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Sample records for cerebral circulation time

  1. Evaluation of angiographic delayed vasospasm due to ruptured aneurysm in comparison with cerebral circulation time measured by IA-DSA

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Yoshikazu; Shima, Takeshi; Nishida, Masahiro; Yamane, Kanji; Okita, Shinji; Hatayama, Takashi; Yoshida, Akira; Naoe, Yasutaka; Shiga, Naoko (Chugoku Rosai Hospital, Hiroshima (Japan))

    1994-05-01

    Delayed vasospasm due to ruptured aneurysm has been basically evaluated by angiographic changes in contrast to clinical features such as delayed ischemic neurological deficits (DIND). However, the discrepancies between angiographic and clinical findings have been pointed out. In this study, angiographic changes and cerebral circulation time in ruptured aneurysms were simultaneously investigated with IA-DSA. Thirty-two patients, who had ruptured aneurysms at the anterior circle of Willis and neck clippings at the acute stage, were investigated. Carotid angiogram was performed with IA-DSA on the 7-13th day after the attack. Angiographic changes were evaluated by Fischer's classification and circulation time was calculated in the following way. A time-density curve was obtained at the two ROI's: the C3-C4 portion and the rolandic vein. Circulation time was defined by the difference between the time showing peak optical density at the carotid and the venous portion. The control value of this circulation time obtained from 20 cases with non-rupture aneurysm and epilepsy was 3.4 sec (53 year old) on the average. X-ray CT scan examination was performed at the same time and clinical features were observed every day. Angiographically, 3 cases were free from vasospasm, 18 cases were found to present slight to moderate vasospasm, and 11 cases showed severe vasospasm. Circulation time in patients with no spasm was 3.6 seconds, in patients with slight to moderate vasospasm it was 4.3 seconds and in patients with severe vasospasm it was 6.8 seconds. Ten patients showing cerebral infarction on CT scans demonstrated significantly long circulation time, 7.0 seconds on the average. And all patients having severe vasospasm with circulation time more than 6 seconds presented DIND such as hemiparesis. (author).

  2. Prolonged Cerebral Circulation Time Is the Best Parameter for Predicting Vasospasm during Initial CT Perfusion in Subarachnoid Hemorrhagic Patients.

    Directory of Open Access Journals (Sweden)

    Chun Fu Lin

    Full Text Available We sought to imitate angiographic cerebral circulation time (CCT and create a similar index from baseline CT perfusion (CTP to better predict vasospasm in patients with subarachnoid hemorrhage (SAH.Forty-one SAH patients with available DSA and CTP were retrospectively included. The vasospasm group was comprised of patients with deterioration in conscious functioning and newly developed luminal narrowing; remaining cases were classified as the control group. The angiography CCT (XA-CCT was defined as the difference in TTP (time to peak between the selected arterial ROIs and the superior sagittal sinus (SSS. Four arterial ROIs were selected to generate four corresponding XA-CCTs: the right and left anterior cerebral arteries (XA-CCTRA2 and XA-CCTLA2 and right- and left-middle cerebral arteries (XA-CCTRM2 and XA-CCTLM2. The CCTs from CTP (CT-CCT were defined as the differences in TTP from the corresponding arterial ROIs and the SSS. Correlations of the different CCTs were calculated and diagnostic accuracy in predicting vasospasm was evaluated.Intra-class correlations ranged from 0.96 to 0.98. The correlations of XA-CCTRA2, XA-CCTRM2, XA-CCTLA2, and XA-CCTLM2 with the corresponding CT-CCTs were 0.64, 0.65, 0.53, and 0.68, respectively. All CCTs were significantly prolonged in the vasospasm group (5.8-6.4 s except for XA-CCTLA2. CT-CCTA2 of 5.62 was the optimal cut-off value for detecting vasospasm with a sensitivity of 84.2% and specificity 82.4.CT-CCTs can be used to interpret cerebral flow without deconvolution algorithms, and outperform both MTT and TTP in predicting vasospasm risk. This finding may help facilitate management of patients with SAH.

  3. Evaluation of asymmetries of blood flow rate and of circulation time by intravenous radionuclide cerebral angiography in patients with ischemic completed stroke.

    Science.gov (United States)

    Bartolini, A; Primavera, A; Gasparetto, B

    1984-12-01

    155 patients with ischemic completed stroke of varying severity and outcome have been evaluated by radionuclide cerebral angiography with analysis of regional time-activity curves. Two parameters have been evaluated: area under the upslope of the curve (Aup) reflecting regional blood flow rate and moment of the whole curve reflecting tracer circulation time (rABCT) Combination of these two methods ensured increased detection of perfusion asymmetries.

  4. Utility of cerebral circulation evaluation in acute traumatic brain injuries

    International Nuclear Information System (INIS)

    Honda, Mitsuru; Sakata, Yoshihito; Haga, Daisuke; Nomoto, Jun; Noguchi, Yoshitaka; Seiki, Yoshikatsu; Machida, Keiichi; Sase, Shigeru

    2007-01-01

    Severe traumatic brain injury (TBI) is well-known to cause dynamic changes in cerebral blood flow (CBF). Specifically, TBI has been reported to cause decreases in cerebral blood flow (CBF). In this study, we measured CBF, mean transit time (MTT) and cerebral blood volume (CBV) after TBI. Our purpose was investigate the possibility of assessing TBI outcome and severity with these physiological parameters, and the clinical utility of cerebral circulation evaluation for brain-oriented intensive care. In 37 patients with TBI, xenon-enhanced CT (Xe-CT) and perfusion CT were performed on days 1-3 post-event (phase II). We measured CBF using Xe-CT and MTT by Perfusion CT and calculated CBV using an AZ-7000W98 computer system. Relative intra cranicol pressure (ICP) and CBF showed significant negative correlations. Relative ICP and MTT showed significant positive correlations. Outcomes, correlated with valuse of CBF and MIT. Significant differences in CBF and MTT were found between favorable outcome group (good recovery (GR) and moderate disability (MD)) and poor outcome group (severe disability (SD), vegetative state (VS), and dead (D)). We could estimate the outcome of patients after TBI by analyzing values of CBF and MTT with a probability of 74%. We evaluated cerebral circulation status in patients with TBI by CBF and MTT. These tests can help to optimize management and improve outcome in patients with severe TBI. (author)

  5. Cerebral circulation and metabolism with recovery of chronic poststroke aphasia

    International Nuclear Information System (INIS)

    Yamada, Tomoyuki; Kabasawa, Hidehiro; Matsubara, Michitaka; Hibino, Hiroaki; Kamimoto, Kaoru; Fukagawa, Kazutoshi

    2004-01-01

    The recruitment of cerebral circulation and oxygen metabolism in the particular brain areas responsible for poststroke aphasia are necessary for recovery. This study was undertaken to investigate changes in cerebral circulation and oxygen metabolism corresponding to improvement of aphasia. Twenty-nine right-handed chronic aphasic patients with left hemispheric stroke were studied. Aphasia was evaluated as the score of fluency, comprehension, repetition and naming by the Western Aphasia Battery (Japanese version). Concurrent with the evaluation of aphasia, positron emission tomography (PET) scans were performed. After several months of speech therapy, PET scans and evaluation of aphasia were reperformed. Both regional cerebral blood flow and the cerebral metabolic rate for oxygen significantly increased in the left upper superior and middle temporal gyri, and in the left upper inferior frontal gyrus in the fair recovery group for comprehension, repetition and naming. In the fair recovery group for fluency, the cerebral metabolic rate for oxygen significantly increased in the left upper superior and middle temporal gyri, but regional cerebral blood flow increased insignificantly in these areas. In the lower white matter of the right parietal lobe, both the regional cerebral blood flow and the cerebral metabolic rate for oxygen were significantly increased in the fair recovery group for all aphasic features. The recruitment of cerebral circulation and oxygen metabolism in the left temporo-parietal area, in the left inferior frontal area, and in the right deep parietal area are essentially responsible for the recovery of aphasia. (author)

  6. Autoregulation of cerebral circulation in hypertension

    International Nuclear Information System (INIS)

    Strandgaard, S.

    1978-01-01

    The present work deals with the effects of high blood pressure on cerebrovascular autoregulation, i.e. the mechanism that ensures a constant blood flow in the brain tissue by way of varying the calibre of the smallest resistance vessels. It has been shown that in patients with severe, untreated or uncontrolled hypertension, the lower limit of autoregulation of cerebral blood flow is shifted towards high blood pressure, thus decreasing the tolerance to acute hypotension. This is a functional correlate of the morphological changes present in hypertensive arterioles, i.e. wall thickening and luminal narrowing. Observations in a group of effectively treated hypertensive patients strongly suggest that a readaptation of autoregulation towards normal may take place during long-term entihypertensive treatment. Thus, the present findings should not be interpreted as a warning against clinical blood pressure lowering, which is known from other studies to protect the patient against stroke. Rather, the present observations are a support of the view that a severely elevated blood pressure should be lowered gradually, without aiming at an immediate normalization. It has also been demonstrated that some hypertensive patients do not readapt their cerebrovascular autoregulation towards normal during treatment, and may be better served in the long run with a blood pressure somewhat above normal. An upper blood pressure limit of autoregulation of cerebral blood flow has been demonstrated in man and experimental animal in the present and other investigations. With a blood pressure rise of 40-60% above the resting awake level, autoregulation may fail, and cerebral blood flow increases. At the upper limit of autoregulation, a ''sausage-string'' pattern has been observed in the cat's pial arterioles. It has been shown by vessel calibre measurements to consist of localized dilatations superimposed on autoregulatory arteriolar constriction. At higher pressures, vasodilatation becomes

  7. Sex Differences in the Cerebral Collateral Circulation.

    Science.gov (United States)

    Faber, James E; Moore, Scott M; Lucitti, Jennifer L; Aghajanian, Amir; Zhang, Hua

    2017-06-01

    Premenopausal women and intact female rodents sustain smaller cerebral infarctions than males. Several sex-dependent differences have been identified as potential contributors, but many questions remain unanswered. Mice exhibit wide variation in native collateral number and diameter (collateral extent) that is dependent on differences in genetic background, aging, and other comorbidities and that contributes to their also-wide differences in infarct volume. Likewise, variation in infarct volume correlates with differences in collateral-dependent blood flow in patients with acute ischemic stroke. We examined whether extent of pial collateral arterioles and posterior communicating collateral arteries (PComAs) differ depending on sex in young, aged, obese, hypertensive, and genetically different mice. We combined new data with meta-analysis of our previously published data. Females of C57BL/6J (B6) and BALB/cByJ (BC) strains sustained smaller infarctions than males after permanent MCA occlusion. This protection was unchanged in BC mice after introgression of the B6 allele of Dce1, the major genetic determinant of variation in pial collaterals among mouse strains. Consistent with this, collateral extent in these and other strains did not differ with sex. Extent of PComAs and primary cerebral arteries also did not vary with sex. No dimorphism was evident for loss of pial collateral number and/or diameter (collateral rarefaction) caused by aging, obesity, and hypertension, nor for collateral remodeling after pMCAO. However, rarefaction was greater in females with long-standing hypertension. We conclude that smaller infarct volume in female mice is not due to greater collateral extent, greater remodeling, or less rarefaction caused by aging, obesity, or hypertension.

  8. Regional effects of craniotomy on cerebral circulation and metabolism

    International Nuclear Information System (INIS)

    Abumiya, Takeo; Sayama, Ichiro; Asakura, Ken; Hadeishi, Hiromu; Mizuno, Makoto; Suzuki, Akifumi; Yasui, Nobuyuki; Shishido, Fumio; Uemura, Kazuo

    1990-01-01

    Regional effects of craniotomy on cerebral circulation and metabolism, such as regional cerebral blood flow (rCBF), regional cerebral oxygen consumption (rCMRO 2 ), regional oxygen extraction fraction (rOEF), and regional cerebral blood volume (rCBV) were examined by a PET (positron emission tomography) study concerning surgery that was performed on un-ruptured aneurysm patients. Eight patients with intracranial un-ruptured aneurysms were studied pre- and post-operatively by the 15 O labelled-gas steady-state method, using HEADTOME-III. All patients underwent aneurysmal surgery performed by the transsylvian approach. There was a significant increase in the mean OEF values taken from the whole-brains of 8 patients, but there was not a significant change in CBF, CMRO 2 or CBV. The increase in OEF was caused by decrease of O 2 content, which was caused by post-operative decrease in the Hb value. So, this OEF increase was not the direct effect of craniotomy. In 2 patients, the rCBF and rCMRO 2 , in the fronto-temporal region (where craniotomy was performed) increased post-operatively. This regional effect suggests transient reactive hyperemia following compressive ischemia during the operative procedure, and metabolic demands for recovery of brain function. In 2 other patients, who had relatively low rCBFs during the pre-operative study, rCBF and rCMRO 2 in the bi-frontal region had decreased more at the post-operative study. This change appears to have been caused by removal of cerebrospinal fluid and depression of the frontal lobe. From this study, it becomes evident that the regional effect of craniotomy on cerebral circulation and metabolism is not so great, when adequate microsurgical techniques are used. (author)

  9. Bond Graph Model of Cerebral Circulation: Toward Clinically Feasible Systemic Blood Flow Simulations

    Science.gov (United States)

    Safaei, Soroush; Blanco, Pablo J.; Müller, Lucas O.; Hellevik, Leif R.; Hunter, Peter J.

    2018-01-01

    We propose a detailed CellML model of the human cerebral circulation that runs faster than real time on a desktop computer and is designed for use in clinical settings when the speed of response is important. A lumped parameter mathematical model, which is based on a one-dimensional formulation of the flow of an incompressible fluid in distensible vessels, is constructed using a bond graph formulation to ensure mass conservation and energy conservation. The model includes arterial vessels with geometric and anatomical data based on the ADAN circulation model. The peripheral beds are represented by lumped parameter compartments. We compare the hemodynamics predicted by the bond graph formulation of the cerebral circulation with that given by a classical one-dimensional Navier-Stokes model working on top of the whole-body ADAN model. Outputs from the bond graph model, including the pressure and flow signatures and blood volumes, are compared with physiological data. PMID:29551979

  10. Utility of evaluation of cerebral circulation for brain-oriented intensive care

    International Nuclear Information System (INIS)

    Honda, Mitsuru; Sakata, Yoshihito; Ichibayashi, Ryo; Yoshihara, Katsunori; Noguchi, Yoshitaka; Seiki, Yoshikatsu; Machida, Keiichi; Sase, Shigeru

    2007-01-01

    Severe traumatic brain injury is widely known to cause a dynamic change in CBF. Especially, a decrease in cerebral blood flow (CBF) has been reported. In the present study we measured CBF, mean transit time (MTT) and cerebral blood volume (CBV). Our purpose was to investigate the possibility to estimate the outcome and severity by using these physiological parameters and the utility of cerebral circulation evaluation for brain-oriented intensive care. In 54 patients with traumatic brain injury, Xe-CT and perfusion CT were performed at the same time in the phase II (Day 1-3). We measured CBF by using Xe-CT and MTT by using Perfusion CT and calculated CBV by using AZ-7000 W 98 computer system. The results were correlated with the outcome and the values of CBF and MTT. Significant differences in CBF and MTT were found between a favorable outcome group and a poor outcome group. We could evaluate the condition of cerebral circulation for patients with traumatic brain injury by analyzing the values of CBF and MTT. In conclusion, these parameters can be helpfull for the optimal management and outcome improvement for the patients with severe traumatic brain injury. (author)

  11. A study of cerebral circulation in patients on moderate hypothermia therapy

    International Nuclear Information System (INIS)

    Honda, Mitsuru; Kushida, Tsuyoshi; Nagao, Takeki; Seiki, Yoshikatsu; Shibata, Iekado

    2003-01-01

    Recently, moderate hypothermia with cooling of the brain to 32-33 deg C has been widely applied to patients with severe brain damage. We evaluated the cerebral circulation of patients treated with moderate hypothermia therapy. In 16 patients with severe brain damage, both Xe-CT and Perfusion CT were performed during moderate hypothermia. The study included 5 head injury patients, 6 anoxic brain patients, 2 subarachnoid hemorrhage patients, 2 cerebral embolization patients and 1 cerebral hemorrhage patient. We measured cerebral blood flow (CBF) values using Xe-CT and mean transit time (MTT) by Perfusion CT and calculated cerebral blood volume (CBV) using an AZ-7000W98 computer system. In 16 patients, moderate hypothermia decreased both CBF (21.4±14.0 ml/100 g/min) and CBV (3.4±2.9 ml/100 g) and increased MTT (9.6±l.9 sec) compared to normal volunteers. However, patients who became brain death during moderate hypothermia maintained high levels of CBF and CBV. Based on the present results, we propose that reduction of CBV and CBF by moderate hypothermia can play important role in protecting brain from damage. (author)

  12. Study of cerebral circulation for patients with head injury

    International Nuclear Information System (INIS)

    Honda, Mitsuru; Aoki, Yoshinori; Noguchi, Yoshitaka; Haga, Daisuke; Seiki, Yoshikatsu; Machida, Keiichi

    2004-01-01

    Severe traumatic brain injury is widely known to cause a dynamic cerebral blood flow (CBF). Especially, decrease of CBF has been reported. In the present study we measured the CBF, the mean transit time (MTT) and the cerebral blood volume (CBV). Our purpose was to investigate the possibility to estimate the outcome with use of these physiological parameters, and the relationship between the clinical condition of the patients and these parameters. In 24 patients with traumatic brain injury, Xe-CT and Perfusion CT were performed at the same time in the phase II (Day 1-3). We measured CBF by using Xe-CT and MTT by using Perfusion CT and calculated CBV by using AZ-7000W98 computer system. We evaluated the relationship between these values and outcome, grading on admission and discussed the usefulness of deciding on courses of treatment. The results were correlated with the outcome and values of CBF and MTT. Significant differences in CBF and MTT were found between favorable outcome group (good recovery (GR) and moderate disability (MD)) and poor outcome group (severe disability (SD), vegetative state (VS) and dead (D)). We could estimate the outcome of patients with subarachnoid hemorrhage (SAH) by analyzing values of CBF and MTT. The probability was 78%. (authors)

  13. The analysis of cerebro-vascular circulation time using digital subtraction angiography (DSA)

    International Nuclear Information System (INIS)

    Han, D. G.; Kim, D. H.; Lee, H. K.; Kwon, K. H.; Kim, K. J.

    1986-01-01

    We analyzed the cerebral arterio-venous circulation time of 141 cases of cranial DSA in 136 patients, for the assessment of cerebral circulatory dynamics. IV-DSA was 111 cases, IA-DSA 30 cases. The results were as follows: 1. There was no significant difference in arterio-venous circulation time between IA-DSA and IV-DSA, if the disease pattern was not considered (P > 0.1). 2. Prolongation of arterio-venous circulation time was noted in the cases of cerebral (cerebellar) hemorrhage, subarachnoid hemorrhage, intracranial hematoma, brain abscess, acute stage of cerebra-vascular occlusive disease, acute stage of postoperative follow up, and acute stage of cerebral contusion (p > 0.05). 3. Compared the chronic stage of cerebra-vascular occlusive disease, postoperative follow up, and cerebral contusion with acute stage, significant decrement of arterio-venous circulation time was resulted (p > 0.05). 4. DSA was a useful modality for the assessment of circulatory dynamics, including measurement of arterio-venous circulation time.

  14. Effect of adrenomedullin on the cerebral circulation: relevance to primary headache disorders

    DEFF Research Database (Denmark)

    Petersen, K A; Birk, S; Kitamura, K

    2009-01-01

    Adrenomedullin (ADM) is closely related to calcitonin gene-related peptide, which has a known causative role in migraine. Animal studies have strongly suggested that ADM has a vasodilatory effect within the cerebral circulation. For these reasons, ADM is also likely to be involved in migraine....... However, the hypothetical migraine-inducing property and effect on human cerebral circulation of ADM have not previously been investigated. Human ADM (0.08 microg kg(-1) min(-1)) or placebo (saline 0.9%) was administered as a 20-min intravenous infusion to 12 patients suffering from migraine without aura...... in a crossover double-blind study. The occurrence of headache and associated symptoms were registered regularly 24 h post infusion. Cerebral blood flow (CBF) was measured by (133)Xenon single-photon emission computed tomography, mean blood flow velocity in the middle cerebral artery (V(MCA)) by transcranial...

  15. Decimeter waves in complex treatment of patients with cerebral blood circulation insufficiency

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    Strelkova, N.I.

    Decimeter waves (DMW) were introduced into the therapeutic armamentarium relatively recently. The effect of DMW on the CNS was studied in the Division of Neurology at the Central Scientific Research Institute of Resort Science and Physiotherapy for a number of years on four groups of patients: (A) Parkinson's Disease Group, (B) patients with sequelae of open and closed craniocerebral injuries, (C) cerebral stroke patients basically of the ischemic type and (D) patients with transitory cerebral circulation disorders. The experience gained showed that the use of DMW improved cerebral circulation and aided in development of collateral circulation. It was found that in cases of tremor Parkinsonism and in epilepsy, DMW therapy should be applied to the collarbone area. Application of DMW in early stages of injury needs further study. Obviously, a single therapeutic intervention cannot provide complete recovery; a combined treatment must be applied, advisably under conditions of a resort spa. 11 references.

  16. Cerebral circulation and prognosis of the patients with hypoxic encephalopathy

    International Nuclear Information System (INIS)

    Nogami, Kenichiro; Fujii, Masami; Kashiwagi, Shiro; Sadamitsu Daikai; Maekawa, Tsuyoshi

    2000-01-01

    Recent progress in cardiopulmonary resuscitation techniques improved the survival rate of patients with acute cardiopulmonary disturbances. However, severe cerebral complications remained frequently in patients who survived the acute stage. Early prediction of cerebral prognosis is important to optimize the management of these patients. We examined the relations between radiological findings (Xe-CT and MRI) and cerebral prognosis. Patients included in this study were selected from all patients with hypoxic encephalopathy admitted to our hospital. There were 11 men and 10 women. Causes of hypoxic encephalopathy were heart disease (11 cases), suffocation (4 cases), CO intoxication (2 cases), asthma (1 case), pneumothorax (1 case), anaphyraxy shock (1 case) and electric shock (1 case). Xe-CT and MRI were carried out 3 weeks after the onset. Cerebral blood flow (CBF) of the patients was measured at rest and 15 minutes after intravenous administration of acetazolamide (1 g). The prognosis was evaluated 3 months after the onset in accordance with Glasgow Outcome Scale (GOS). Low hemispheric CBF (30 ml/100 g/min), poor reactivity of acetazolamide challenge test (10 ml/100 g/min), presence of hyperintensity areas in the basal ganglia in T1 weighted images (T1WI) and T2 weighted images (T2WI) are the factors associated with poor outcome in hypoxic encephalopathy. (author)

  17. The effects of superimposed tilt and lower body negative pressure on anterior and posterior cerebral circulations.

    Science.gov (United States)

    Tymko, Michael M; Rickards, Caroline A; Skow, Rachel J; Ingram-Cotton, Nathan C; Howatt, Michael K; Day, Trevor A

    2016-09-01

    Steady-state tilt has no effect on cerebrovascular reactivity to increases in the partial pressure of end-tidal carbon dioxide (PETCO2). However, the anterior and posterior cerebral circulations may respond differently to a variety of stimuli that alter central blood volume, including lower body negative pressure (LBNP). Little is known about the superimposed effects of head-up tilt (HUT; decreased central blood volume and intracranial pressure) and head-down tilt (HDT; increased central blood volume and intracranial pressure), and LBNP on cerebral blood flow (CBF) responses. We hypothesized that (a) cerebral blood velocity (CBV; an index of CBF) responses during LBNP would not change with HUT and HDT, and (b) CBV in the anterior cerebral circulation would decrease to a greater extent compared to posterior CBV during LBNP when controlling PETCO2 In 13 male participants, we measured CBV in the anterior (middle cerebral artery, MCAv) and posterior (posterior cerebral artery, PCAv) cerebral circulations using transcranial Doppler ultrasound during LBNP stress (-50 mmHg) in three body positions (45°HUT, supine, 45°HDT). PETCO2 was measured continuously and maintained at constant levels during LBNP through coached breathing. Our main findings were that (a) steady-state tilt had no effect on CBV responses during LBNP in both the MCA (P = 0.077) and PCA (P = 0.583), and (b) despite controlling for PETCO2, both the MCAv and PCAv decreased by the same magnitude during LBNP in HUT (P = 0.348), supine (P = 0.694), and HDT (P = 0.407). Here, we demonstrate that there are no differences in anterior and posterior circulations in response to LBNP in different body positions. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  18. Aneurysms of the anterior and posterior cerebral circulation: comparison of the morphometric features.

    Science.gov (United States)

    Tykocki, Tomasz; Kostkiewicz, Bogusław

    2014-09-01

    Intracranial aneurysms (IAs) located in the posterior circulation are considered to have higher annual bleed rates than those in the anterior circulation. The aim of the study was to compare the morphometric factors differentiating between IAs located in the anterior and posterior cerebral circulation. A total number of 254 IAs diagnosed between 2009 and 2012 were retrospectively analyzed. All patients qualified for diagnostic, three-dimensional rotational angiography. IAs were assigned to either the anterior or posterior cerebral circulation subsets for the analysis. Means were compared with a t-test. The univariate and stepwise logistic regression analyses were used to determine the predictors of morphometric differences between the groups. For the defined predictors, ROC (receiver-operating characteristic) curves and interactive dot diagrams were calculated with the cutoff values of the morphometric factors. The number of anterior cerebral circulation IAs was 179 (70.5 %); 141 (55.5 %) aneurysms were ruptured. Significant differences between anterior and posterior circulation IAs were found for: the parent artery size (5.08 ± 1.8 mm vs. 3.95 ± 1.5 mm; p 45) and aspect ratio (AR) (1.91 ± 0.8 vs. 2.75 ± 1.8; p = 0.02). Predicting factors differentiating anterior and posterior circulation IAs were: the AR (OR = 2.20; 95 % CI 1.80-270; Is 270 correct or should it be 2.70 and parent artery size (OR = 0.44; 95 % CI 0.38-0.54). The cutoff point in the ROC curve was 2.185 for the AR and 4.89 mm for parent artery size. Aspect ratio and parent artery size were found to be predictive morphometric factors in differentiating between anterior and posterior cerebral IAs.

  19. A study of cerebral circulation, metabolism and MRI findings in patients with chronic cerebral circulatory insufficiency

    International Nuclear Information System (INIS)

    Kondo, Susumu

    1995-01-01

    Chronic cerebral circulatory insufficiency (CCCI) is a recently proposed clinical entity characterized by symptoms such as dizziness, a feeling of heavy-headedness or vague numbness without any neurological signs or organic vascular lesions on CT. In order to elucidate its pathogenesis, ultrasonic quantitative blood flow measurement system, positron emission tomography (PET) and MRI were employed to study three groups of subjects: 60 subjects with CCCI (group A), 44 subjects with risk factors for cerebrovascular disease but without neurological abnormalities (group B), and 40 normal healthy volunteers (group C). The results are summarized as follows: Mean common carotid blood flow decreased with age in all groups. Common carotid blood flow was lowest in group A and second lowest in group B in every decade of patient age. PET study revealed that CBF and CMRO 2 in all regions examined were significantly lower in group A than in group C. The incidence of MR signal abnormalities in the white matter increased with age. Group A had the highest incidence, and group C had the lowest. Reduction in mean common carotid blood flow and cerebral blood flow was associated with increasing incidence and severity of MR signal abnormalities. These findings indicate that CCCI is a pathologic condition closely related to diffuse cerebral low perfusion resulting from cerebral arteriosclerosis. The symptoms seen in this condition, which are apt to be taken lightly, may warn of impending ischemic stroke. (author)

  20. Portal pressure correlated to visceral circulation times

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    Friman, L [Serafimerlasarettet, Stockholm (Sweden)

    1979-01-01

    Visceral angiography was performed in 7 patients with normal portal pressure and in 10 with portal hypertension. Circulation times, size of vessels and portal pressure were determined. At celiac angiography, a direct correlation was found between time for maximum filling of portal vein and portal pressure, provided no vascular abnormalities existed. At superior mesenteric angiography such a correlation was not found; loss of flow by shunts in portal hypertension being one explanation. Portocaval shunts are common in the celiac system, but uncommon in the superior mesenteric system.

  1. Portal pressure correlated to visceral circulation times

    International Nuclear Information System (INIS)

    Friman, L.

    1979-01-01

    Visceral angiography was performed in 7 patients with normal portal pressure and in 10 with portal hypertension. Circulation times, size of vessels and portal pressure were determined. At celiac angiography, a direct correlation was found between time for maximum filling of portal vein and portal pressure, provided no vascular abnormalities existed. At superior mesenteric angiography such a correlation was not found; loss of flow by shunts in portal hypertension being one explanation. Portocaval shunts are common in the celiac system, but uncommon in the superior mesenteric system. (Auth.)

  2. Development of a cerebral circulation model for the automatic control of brain physiology.

    Science.gov (United States)

    Utsuki, T

    2015-01-01

    In various clinical guidelines of brain injury, intracranial pressure (ICP), cerebral blood flow (CBF) and brain temperature (BT) are essential targets for precise management for brain resuscitation. In addition, the integrated automatic control of BT, ICP, and CBF is required for improving therapeutic effects and reducing medical costs and staff burden. Thus, a new model of cerebral circulation was developed in this study for integrative automatic control. With this model, the CBF and cerebral perfusion pressure of a normal adult male were regionally calculated according to cerebrovascular structure, blood viscosity, blood distribution, CBF autoregulation, and ICP. The analysis results were consistent with physiological knowledge already obtained with conventional studies. Therefore, the developed model is potentially available for the integrative control of the physiological state of the brain as a reference model of an automatic control system, or as a controlled object in various control simulations.

  3. The effects of superimposed tilt and lower body negative pressure on anterior and posterior cerebral circulations

    OpenAIRE

    Tymko, Michael M.; Rickards, Caroline A.; Skow, Rachel J.; Ingram?Cotton, Nathan C.; Howatt, Michael K.; Day, Trevor A.

    2016-01-01

    Abstract Steady?state tilt has no effect on cerebrovascular reactivity to increases in the partial pressure of end?tidal carbon dioxide (PETCO 2). However, the anterior and posterior cerebral circulations may respond differently to a variety of stimuli that alter central blood volume, including lower body negative pressure (LBNP). Little is known about the superimposed effects of head?up tilt (HUT; decreased central blood volume and intracranial pressure) and head?down tilt (HDT; increased ce...

  4. Significance of non-specific complaints in asymptomatic cerebral infarction. Approach based on the cerebral circulation

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    Sakayori, Osamu; Kitamura, Shin; Nagazumi, Atsushi; Terashi, Akirou [Nippon Medical School, Tokyo (Japan)

    1997-10-01

    Seventy-three cases with asymptomatic cerebral infarction detected by MR scanning and 80 cases of past stroke patients were evaluated. The regional cerebral blood flow (CBF) using the SPECT, idoine-123-IMP autoradiography (ARG) method was measured. Twenty-two patients with non-specific complaints (dizziness, numbness of the extremities, headache, etc.) without cerebrovascular risk factors were also examined as controls. Fifty-two percent of the asymptomatic infarction cases had non-specific complaints. The regional CBF in all cerebral non-specific complaints showed significantly lower values as compared to the controls. There was no difference in CBF values between the asymptomatic infarction cases with non-specific complaints and the past stroke patients. Among the asymptomatic infarction patients, cases with both non-specific complaints and hypertension displayed significantly lower CBF values, especially in the frontal and temporal cortical regions, than did cases without non-specific complaints or hypertension. These findings suggest that the patient`s complaints should be taken into consideration when determining the clinical treatment of asymptomatic infarction. (author)

  5. CHARACTERIZATION OF PATIENTS WITH ENDOVASCULAR TREATMENT OF DISSECTING ANEURYSMS OF POSTERIOR CEREBRAL CIRCULATION IN CARTAGENA DE INDIAS

    OpenAIRE

    Rueda-Tamayo Leidy; Almeida-Pérez Rafael; De la Rosa-Manjarrez Ginna; Orozco-Gómez Fernando; Carrasquilla-Meléndez Rubén

    2015-01-01

    Introduction: the intracraneal aneurysms are local and permanent dilations in the artery. Objective: to describe the clinical, imagenologic and effectiveness of endovascular treatment in terms of its independence and mortality in patients with dissecting aneurysms of posterior cerebral circulation in Cartagena. Methods: a descriptive study was carried out with patients 18 years or older with a diagnosis of dissecting aneurysms of posterior cerebral circulation who received ...

  6. Studies on intracranial collateral circulation with multi-slice CT angiography in patients with symptomatic cerebral artery stenosis

    Directory of Open Access Journals (Sweden)

    Shu-qing ZHOU

    2011-06-01

    Full Text Available Objective To explore the features of intracranial collateral circulation in patients with symptomatic cerebral artery stenosis.Method Ninety-four patients with ischemic cerebrovascular disease admitted from Apr.2004 to Jun.2009 were involved in present study.All the patients were examined with cerebral multi-slice CT angiography,and the features of cerebral artery stenosis and intracranial collateral circulation were evaluated using maximum intensity projection(MIP and volume rendering(VR images of CT angiography.Result Of the 94 patients involved,48 were diagnosed as cerebral artery stenosis,including 29 cases of cerebral infarction,18 of transient ischemic attack(TIA and 1 of moyamoya disease(MMD.Among the 14 cases of severe cerebral artery stenosis or occlusion,cerebral infarction was found in 6 cases with lesser intracranial collateral vessels(including massive cerebral infarction in 4 cases and watershed infarction in 2 cases,and focal infarction of central semi-ovale in 1 case and TIA in 7 cases were found with abundant intracranial collateral vessels.Multiple lacunar infarction was found in 22 cases of mild or moderate cerebral artery stenosis,but there was no significant correlation between the stenosed arteries and infarction sites.Abundant intracranial collateral vessels were found in one patient with Moyamoya disease but no infarction was observed.Conclusions Intracranial collateral circulation plays an important role of compensation in patients with severe cerebral artery stenosis or occlusion.Cerebral angiography with multi-slice CT is of great significance in evaluation of cerebral artery stenosis and intracranial collateral circulation.

  7. Transcephalic electrical impedance in the study of cerebral circulation in a juvenile pig model.

    Science.gov (United States)

    Grönlund, J; Bartocci, M; Kääpä, P; Jahnukainen, T; Rautanen, M; Halkola, L; Välimäki, I

    1997-11-01

    Transcephalic electrical impedance offers a technique for non-invasive, cot-side monitoring of neonatal cerebral circulation but the exact nature of the signal is somewhat ambiguous. The impedance signal is examined in an animal project where the ventilator settings are adjusted (20 min-1-10 min-1-40 min-1 for 10 min periods each) to produce circulatory changes. Six juvenile pigs are intubated, and ECG, arterial blood pressure, carotid flow (CF) by electromagnetic flowmeter and impedance are continuously monitored and stored on analogue tape. Cardiac output by thermodilution, blood oxygen (pO2) and carbon dioxide (pCO2) tensions are measured. ECG is converted to heart rate, mean blood pressure is integrated, and the high-frequency (1.50-4.00 Hz) component of the impedance signal delta Z is computed using autoregressive spectral estimation. Stroke volume, peripheral vascular resistance (PVR) and cerebral vascular resistance (CVR) are calculated. pCO2 and CF increase and pO2 decreases during hypoventilation. CF correlates positively with cardiac output, stroke volume, delta Z and pCO2, and negatively with pO2 and CVR. delta Z correlates positively with heart rate and cardiac output, and negatively with PVR and CVR. It is concluded that the impedance signal is related to the amount of blood transmitted to the brain by every beat of the heart, depending on the changes in both the systemic circulation and the cerebral vascular compliance.

  8. Cerebral circulation, metabolism, and blood-brain barrier of rats in hypocapnic hypoxia

    International Nuclear Information System (INIS)

    Beck, T.; Krieglstein, J.

    1987-01-01

    The effects of hypoxic hypoxia on physiological variables, cerebral circulation, cerebral metabolism, and blood-brain barrier were investigated in conscious, spontaneously breathing rats by exposing them to an atmosphere containing 7% O 2 . Hypoxia affected a marked hypotension, hypocapnia and alkalosis. Cortical tissue high-energy phosphates and glucose content were not affected by hypoxia, glucose 6-phosphate lactate, and pyruvate levels were significantly increased. Blood-brain barrier permeability, regional brain glucose content and lumped constant were not changed by hypoxia. Local cerebral glucose utilization (LCGU) rose by 40-70% of control values in gray matter and by 80-90% in white matter. Under hypoxia, columns of increased and decreased LCGU and were detectable in cortical gray matter. Color-coded [ 14 C]2-deoxy-D-glucose autoradiograms of rat brain are shown. Local cerebral blood flow (LCBF) increased by 50-90% in gray matter and by up to 180% in white matter. Coupling between LCGU and LCBF in hypoxia remained unchanged. The data suggests a stimulation of glycolysis, increased glucose transport into the cell, and increased hexokinase activity. The physiological response of gray and white matter to hypoxia obviously differs. Uncoupling of the relation between LCGU and LCBF does not occur

  9. The effect of circulating adenosine on cerebral haemodynamics and headache generation in healthy subjects

    DEFF Research Database (Denmark)

    Birk, S; Petersen, K.A.; Kruuse, Christina Rostrup

    2005-01-01

    . Headache was rated on a verbal scale (0-10). Regional cerebral blood flow (rCBF) with 133Xe inhalation and single-photon emission computed tomography (SPECT) and MCA flow velocity (V(MCA)) with transcranial Doppler, were measured in direct sequence. Six participants developed headache during 80 microg kg.......16) were found between treatments. A significant dilation of the superficial temporal artery (STA) was seen (P circulating adenosine has no effect on rCBF or V(MCA), while it dilates the STA and causes very mild headache....

  10. Relation between prognosis and collateral circulation or recanalization in occlusive cerebral vascular diseases

    International Nuclear Information System (INIS)

    Saito, Yuko

    1982-01-01

    CT images and angiograms were compared, in occlusive cerebral vascular diseases with complete stroke in the region of internal carotid artery, and following subjects were discussed. 1) Relation between size of final low density area on CT and prognosis. 2) Effectiveness of collateral circulation and recanalization to the low density area on CT in the teritorry of occluded artery. For the subject 1,100 cases of infarction of the region of middle cerebral artery were chosen at random, and the prognosis was compared with the size of low density area on CT. For the subject 2,186 cases of infarction in the region on internal carotid artery were selected, and CT images and angiograms were compared, considering the duration between stroke and angiography. With these studies, following conclusions were obtained. There is tendency that cases with the smaller low density areas on CT have the better prognosis. The low density on CT appeares inside of the teritorry of the occluded artery. When there is neither collateral circulation nor recanalization, appearance of the low density on CT is not avoided. Collateral circulation or recanalization is able to rescue the affected area from appearance of low density on CT, even if it is formed later than 6 hours after ictus. The critical period when collateral circulation or recanalization effects on the involved area is variable depending on each cases, but it is suspected to be 24 or 72 hours after onset. Blood supply which begins later than 73 hours after occlusion of artery does not effect on the involved area. (J.P.N.)

  11. Relation between prognosis and collateral circulation or recanalization in occlusive cerebral vascular diseases

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Yuko (Tokyo Women' s Medical Coll. (Japan))

    1982-09-01

    CT images and angiograms were compared, in occlusive cerebral vascular diseases with complete stroke in the region of internal carotid artery, and following subjects were discussed. 1) Relation between size of final low density area on CT and prognosis. 2) Effectiveness of collateral circulation and recanalization to the low density area on CT in the territory of occluded artery. For the subject 1,100 cases of infarction of the region of middle cerebral artery were chosen at random, and the prognosis was compared with the size of low density area on CT. For the subject 2,186 cases of infarction in the region on internal carotid artery were selected, and CT images and angiograms were compared, considering the duration between stroke and angiography. With these studies, following conclusions were obtained. There is tendency that cases with the smaller low density areas on CT have the better prognosis. The low density on CT appears inside of the territory of the occluded artery. When there is neither collateral circulation nor recanalization, appearance of the low density on CT is not avoided. Collateral circulation or recanalization is able to rescue the affected area from appearance of low density on CT, even if it is formed later than 6 hours after ictus. The critical period when collateral circulation or recanalization effects on the involved area is variable depending on each cases, but it is suspected to be 24 or 72 hours after onset. Blood supply which begins later than 73 hours after occlusion of artery does not effect on the involved area.

  12. A model of the instantaneous pressure-velocity relationships of the neonatal cerebral circulation.

    Science.gov (United States)

    Panerai, R B; Coughtrey, H; Rennie, J M; Evans, D H

    1993-11-01

    The instantaneous relationship between arterial blood pressure (BP) and cerebral blood flow velocity (CBFV), measured with Doppler ultrasound in the anterior cerebral artery, is represented by a vascular waterfall model comprising vascular resistance, compliance, and critical closing pressure. One min recordings obtained from 61 low birth weight newborns were fitted to the model using a least-squares procedures with correction for the time delay between the BP and CBFV signals. A sensitivity analysis was performed to study the effects of low-pass filtering (LPF), cutoff frequency, and noise on the estimated parameters of the model. Results indicate excellent fitting of the model (F-test, p model parameters have a mean correlation coefficient of 0.94 with the measured flow velocity tracing (N = 232 epochs). The model developed can be useful for interpreting clinical findings and as a framework for research into cerebral autoregulation.

  13. The relationship between cerebral infarction on MR and angiographic findings in moyamoya disease: significance of the posterior circulation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Ja; Song, Soon Young [College of Medicine, Kwangdong Univ., Koyang (Korea, Republic of); Yu, Won Jong; Jung, So Lyung; Chung, Bong Gak; Kag, Si Won [College of Medicine, The Catholic Univ. of Korea, Seoul (Korea, Republic of); Kim, Man Deuk [College of Medicine, Pochon CHA Univ., Pochon (Korea, Republic of)

    2002-06-01

    To investigate the relationship between changes in the posterior and anterior circulation, as seen at angiography, and the frequency and extent of cerebral infarction revealed by MR imaging in moyamoya disease. This study involved 34 patients (22 females and 12 males, aged 2-52 years) in whom cerebral angiography revealed the presence of moyamoya disease (bilateral; unilateral= 24:10; total hemispheres=58) and who also underwent brain MR imaging. To evaluate the angiographic findings, we applied each angiographic staging system to the anterior and posterior circulation. Leptomeningeal collateral circulation from the cortical branches of the posterior cerebral artery (PCA) was also assigned one of four grades. At MR imaging, areas of cerebral cortical or subcortical infarction in the hemisphere were divided into six zones. White matter and basal ganglionic infarction, ventricular dilatation, cortical atrophy, and hemorrhagic lesions were also evaluated. To demonstrate the statistical significance of the relationship between the angiographic and the MR findings, both the Mantel-Haenszel chi-square test for trend and the chi-square test were used. The degree of steno-occlusive PCA change correlated significantly with the internal carotid artery (ICA) stage (p<0.0001). As PCA stages advanced, the degree of leptomeningeal collaterals from the PCA decreased significantly (P<0.0001), but ICA stages were not significant (p>0.05). The prevalence of infarction showed significant correlation with the degree of steno-occlusive change in both the ICA and PCA. The degree of cerebral ischemia in moyamoya patients increased proportionally with the severity of PCA stenosis rather than with that of steno-occlusive lesins of the anterior circulation. Infarctions tended to be distributed in the anterior part of the hemisphere at PCA state I or II, while in more advanced PCA lesions, they were also found posteriorly, especially in the territories of the posterior middle cerebral artery

  14. Radionuclide examination of the cerebral circulation with the 'Fucks-Knipping Gamma-Camera'

    International Nuclear Information System (INIS)

    Arnim, W.H. von; Schicha, H.; Becker, V.; Vyska, K.; Feinendegen, L.E.

    1976-01-01

    In order to analyze cerebral blood flow for diagnostic purposes, Indium 113m-DTPA was i.v. injected into seated patients, and time-activity curves were registered by a multifacet gamma camera (Fucks-Knipping) form 8 regions of interest, from the median area and from the right and left side of the head: 3 from the hemisphere, 3 from the brain stem, 2 from the large arteries of the neck. The results from 14 patients with chronic impairment of cerebral blood flow were compared with normal data from 20 healthy individuals. The time activity curves were analyzed for peak-height, mean transit time, and ratio peak to plateau height. The individual parameters were investigated for the degree of their correlation in a multiparameter system. The results from the patients indicated for the different single parameters a non-uniform response. There was also no correlation between the deviation of different parameters, between single pathological parameters and the degree and the site of blood flow impairment. On the other hand, a positive correlation was found between the number of pathological parameters and the degree of blood flow impairment irrespective of the site of its localization. Reason for this result probably is the variable location and degree of blood flow compensation by collaterals, which predominantly are expected at the cerebral base. The data indicate the potential usefulness of the application of the multiparameter analysis to quantitatively detect the degree of impairment of cerebral blood flow without regard to its topography. In this respect, the method, here described, promises to be of clinical value for non-invasive and non-hazardous diagnostic screening of cerebral blood flow. (orig.) [de

  15. The outcome of a surgical protocol based on ischemia overprotection in large and giant aneurysms of the anterior cerebral circulation.

    Science.gov (United States)

    Imai, Hideaki; Watanabe, Katsushige; Miyagishima, Takaaki; Yoshimoto, Yuhei; Kin, Taichi; Nakatomi, Hirofumi; Saito, Nobuhito

    2016-07-01

    Aiming to define the optimal treatment of large and giant aneurysms (LGAs) in the anterior circulation, we present our surgical protocol and patient outcome. A series of 42 patients with intracavernous LGAs (n = 16), paraclinoid (C2) LGAs (n = 17), and peripheral (middle cerebral artery-MCA or anterior cerebral artery-ACA) LGAs (n = 9) were treated after bypass under motor evoked potential (MEP) monitoring. Preoperatively, three categories of ischemic tolerance during internal carotid artery (ICA) occlusion were defined on conventional angiography: optimal, suboptimal, and insufficient collaterals. Accordingly, three types of bypass: low flow (LFB), middle flow (MFB) and high flow (HFB) were applied for the cases with optimal, suboptimal, and insufficient collaterals, respectively. Outcome was evaluated by the Glasgow Outcome Scale (GOS). All patients had excellent GOS score except one, who suffered a major ischemic stroke immediately after surgery for a paraclinoid lesion. Forty-one patients were followed up for 87.1 ± 40.1 months (range 13-144 months). Intracavernous LGAs were all treated by proximal occlusion with bypass surgery. Of paraclinoid LGA patients, 15 patients had direct clipping under suction decompression and other 2 patients with recurrent aneurysms had ICA (C2) proximal clipping with HFB. MEP monitoring guided for temporary clipping time and clip repositioning, observing significant MEP changes for up to 6 min duration. Of 9 peripheral LGAs patients 7 MCA LGAs had reconstructive clipping (n = 4) or trapping (n = 3) with bypass including LFB in 3 cases, MFB in 1 and HFB in 1. Two ACA LGAs had clipping (n = 1) or trapping (n = 1) with A3-A3 bypass. The applied protocol provided excellent results in intracavernous, paraclinoid, and peripheral thrombosed LGAs of the anterior circulation.

  16. Experimental study of the long-term effects of cephalic irradiation on local cerebral circulation. Preliminary results

    International Nuclear Information System (INIS)

    Dufour, R.

    1978-01-01

    The purpose of this experimental study was to follow the effects of fractionated cehalic irradiation (average dosee 100 rads) on local cerebral blood circulation. Observations were made on unanaesthetized rabbits in terms of two circulatory responses, one of which is associated with rapid eye movement sleep and the other produced by inhalation of a mixture of air and 5% carbon dioxide. Both responses take the form of a characteristic increase in cerebral flow. The method of measuring variations in local cerebral flow relies on changes in the thermal conduction of cerebral tissue associated with the changes in circulation. Placement of the measuring probes entails fixation of electrodes for deriving the cortical and hippocampal electroencephalographic activity. The prreliminary results refer to two animalswhich were subjected to three andd four cephalic irradiations off 1000 rads, spaced at least a month apart, at a dose rate of 70 rad min -1 . The increase and the rate of increase of cerebral flow during rapid eye movement sleep and COBinhalation proved significantly greater than the reference values from the third month on (after the second irradiation) in the case of one animal and from the sixth month on (after the third irradiation) in the case of the other. The response during rapid eye movement sleep was equal to 140% of the reference amplitude during the two observation periods in the first case, and to 110 and 150% respectively after the third and fourth irradiations in the second case. The CO 2 response was 140% of the reference value during the two observation periods in the first case, and 135% after the third and fourth irradiations in the second case. The functional significance of these changes in cerebral output is analysed in terms of the regulation of cerebral circulation. (author)

  17. Evaluation of regional cerebral circulation and metabolism in moyamoya disease using positron emission computed tomography

    International Nuclear Information System (INIS)

    Kuwabara, Yasuo

    1986-01-01

    Regional cerebral blood flow, oxygen extraction fraction, metabolic rate of oxygen, blood volume and transit time were evaluated in 11 patients with moyamoya disease and 3 with suspected moyamoya disease using positron emission computed tomography. Eight of them were examined before and after EC-IC bypass surgery. Moyamoya patients were classified into four groups, namely, pediatric bilateral chronic type (over 5 years from onset), pediatric bilateral early type (within 5 years from onset), pediatric unilateral early type and adult type, according to age, duration of disease from onset and angiographic findings. These four groups showed different patterns on PET images; diffusely decreased CBF and CMRO2 in pediatric bilateral chronic type, decreased CBF and increased OEF in the frontal or temporoparietal region in pediatric bilateral early type, diffusely decreased CBF and increased OEF in the unilateral cerebral hemisphere in pediatric unilateral cerebral hemisphere in pediatric unilateral early type, and decreased CBF and CMRO2 in adult type. An increase of rCBV was demonstrated in frontal regions or basal ganglia in all groups, more prominently in pediatric patients. This was thought to be a common finding in moyamoya disease, corresponding to moyamoya vessels. Staging of moyamoya disease by PET was presented and compared to the angiographic staging. They were significantly correlated, and the stage 3 on PET image with decreased CMRO2 corresponded to the stage 3 or 4 on angiography, the most active stage of moyamoya disease. PET revealed increased CBF in the cortical area around EC-IC bypass but no remarkable changes in mean values of rCBF, OEF, CMRO2 and CBV in cerebral hemisphere. Some patients showed decreased rCBV in the basal ganglia. (J.P.N.)

  18. Alcohol abuse and docosahexaenoic acid: Effects on cerebral circulation and neurosurvival

    Directory of Open Access Journals (Sweden)

    Michael A Collins

    2015-01-01

    Full Text Available Alcohol abuse and alcoholism are major and yet surprisingly unacknowledged worldwide causes of brain damage, cognitive impairment, and dementia. Chronic abuse of alcohol is likely to elicit significant changes in essential polyenoic fatty acids and the membrane phospholipids (PLs that covalently contain them in brain membranes. Among the fatty acids of the omega-3 polyenoic class, docosahexaenoic acid (DHA, which is relatively concentrated in mammalian brain, has proven particularly important for proper brain development as well as neurosurvival and protection. DHA losses in brains of chronic alcohol-treated animals may contribute to alcohol′s neuroinflammatory and neuropathological sequelae; indeed, DHA supplementation has beneficial effects, including the possibility that its documented augmenting effects on cerebral circulation could be important. The neurochemical mechanisms by which DHA exerts its effects encompass several signaling routes involving both the membrane PLs in which DHA is esterified as well as unique neuroactive metabolites of the free fatty acid itself. In view of indications that brain DHA deficits are a deleterious outcome of human alcoholism, increasing brain DHA via supplementation during detoxification of alcoholics could potentially fortify against dependence-related neuroinjury.

  19. [Effects of combined action of radon baths and transcranial magnetotherapy on cerebral circulation in patients in an intermediate period of a mild craniocerebral trauma].

    Science.gov (United States)

    Moliavchikova, O V; Cherevashchenko, L A; Grinzaĭd, Iu M; Aĭvazov, V N; Zhuravlev, M E

    2007-01-01

    The authors propose combined therapy improving cerebral circulation in patients in an intermediate period of a mild craniocerebral trauma. The combination consists of radon baths and transcranial magnetotherapy which raise blood volume filling, relieve vascular resistance, improve venous outflow.

  20. Bilateral Superior Cerebellar Artery Embolic Occlusion with a Fetal-Type Posterior Cerebral Artery Providing Collateral Circulation

    Directory of Open Access Journals (Sweden)

    Taylor J. Bergman

    2016-12-01

    Full Text Available Bilateral infarction of the superior cerebellar arteries with sparing of the rest of the posterior circulation, particularly the posterior cerebral arteries, is an uncommon finding in neurological practice. Most commonly, the deficits of the superior cerebellar arteries and posterior cerebral arteries occur together due to the close proximity of their origins at the top of the basilar artery. A patient was transferred to the neurological intensive care unit with a history of recent-onset falls from standing, profound hypertension, dizziness, and headaches. The neurological exam revealed cerebellar signs, including dysmetria of the right upper extremity and a decreased level of consciousness. Computed tomography of the head and neck revealed decreased attenuation throughout most of the cerebellar hemispheres suggestive of ischemic injury with sparing of the rest of the brain. Further investigation with a computed tomography angiogram revealed a fetal-type posterior cerebral artery on the right side that was providing collateral circulation to the posterior brain. Due to this embryological anomaly, the patient was spared significant morbidity and mortality that would have likely occurred had the circulation been more typical of an adult male.

  1. Therapeutic efficiency of decimeter range waves and their effect on cerebral circulation in patients during recovery period after surgery performed on intracranial arteries

    Energy Technology Data Exchange (ETDEWEB)

    Danilova, D.P.; Strelkova, N.I.; Streltsova, E.N.

    The goal of this work was to evaluate the therapeutic effect of an electromagnetic field in the decimeter range on focal neurologic symptoms and cerebral circulation in patients recovering from surgery on intracranial arteries. This treatment led to regression of focal neurologic symptoms and improved cerebral circulation in 86.3% of patients who tolerated this procedure rather well. This approach was recommended as a method of choice for rehabilitative treatment during the postsurgical period. 7 references, 1 figure.

  2. A study on regional cerebral circulation in stroke patients with aphasia

    International Nuclear Information System (INIS)

    Kudo, Ryozo

    1985-01-01

    To study the pathophysiology of aphasia due to cerebral stroke, regional cerebral blood flow (rCBF) was measured by the 133 Xe clearance method and the volume of low density area (LDA) was estimated on the basis of computerized tomography in 43 thrombotic (24 aphasia and 19 non-aphasia), 30 hemorrhagic (16 aphasia and 14 non-aphasia) and 6 non-stroke cases. 1) In the healthy hemisphere, rCBF showed no significant difference between aphasia and non-aphasia in both thrombotic and hemorrhagic cases. In the affected hemisphere, thrombotic cases showed significantly decreased rCBF in aphasic cases as compared to non-aphasic, however, hemorrhagic cases revealed no difference. 2) LDA volume showed no significant difference between aphasia and non-aphasia in cerebral thrombosis, however, LDA volume in non-aphasia was smaller than that in aphasia in cerebral hemorrage. 3) Significant differences in the pathophysiology of aphasia due to cerebral stroke were recognized between cerebral thrombosis and cerebral hemorrhage. Such differences should be taken into consideration in the management and treatment of aphasia caused by cerebral stroke. (author)

  3. Hypoxia compounds exercise-induced free radical formation in humans; partitioning contributions from the cerebral and femoral circulation

    DEFF Research Database (Denmark)

    Bailey, Damian M; Rasmussen, Peter; Evans, Kevin A

    2018-01-01

    This study examined to what extent the human cerebral and femoral circulation contribute to free radical formation during basal and exercise-induced responses to hypoxia. Healthy participants (5♂, 5♀) were randomly assigned single-blinded to normoxic (21% O2) and hypoxic (10% O2) trials...... hypoxia (P free radical-mediated lipid peroxidation subsequent to inadequate antioxidant defense. This was pronounced during exercise across the femoral circulation in proportion to the increase in local O2 uptake (r = -0.397 to -0.459, P = 0.037 to 0...... with measurements taken at rest and 30min after cycling at 70% of maximal power output in hypoxia and equivalent relative and absolute intensities in normoxia. Blood was sampled from the brachial artery (a), internal jugular and femoral veins (v) for non-enzymatic antioxidants (HPLC), ascorbate radical (A...

  4. Central Pulsatile Pressure and Flow Relationship in the Time and Frequency Domain to Characterise Hydraulic Input to the Brain and Cerebral Vascular Impedance.

    Science.gov (United States)

    Kim, Mi Ok; O'Rourke, Michael F; Adji, Audrey; Avolio, Alberto P

    2016-01-01

    In the time domain, pulsatile flow and pressure can be characterised as the ratio of the late systolic boost of flow or pressure to the pulse amplitude so as to estimate the hydraulic input to the brain. While vascular impedance has been widely used to represent the load presented to the heart by the systemic circulation, it has not been applied to the cerebral circulation.We set out to study the relationship between the pressure and the flow augmentation index (AIx) in the time domain and to determine cerebral vascular impedance using aortic blood pressure and cerebral blood flow waveforms in the frequency domain. Twenty-four young subjects (aged 21-39 years) were recruited; aortic pressure was derived using SphygmoCor from radial pressure. Flow waveforms were recorded from the middle cerebral artery. In three subjects, we performed the Valsalva manoeuvre to investigate their response to physiological intervention. There was a linear relationship between flow and pressure AIx, and cerebral impedance values were similar to those estimated for low resistance vascular beds. Substantial change in pressure and flow wave contour was observed during the Valsalva manoeuvre; however, the relationship in both the time and the frequency domains were unchanged. This confirms that aortic pressure and cerebral flow waveform can be used to study cerebral impedance.

  5. Seizures following carotid endarterectomy in patients with severely compromised cerebral circulation

    DEFF Research Database (Denmark)

    Nielsen, Tina G; Sillesen, H; Schroeder, T V

    1995-01-01

    AND METHODS: We determined the incidence of postendarterectomy seizures related to haemodynamic impairment in terms of intraoperatively measured perfusion pressure in 151 patients undergoing 153 carotid endarterectomies. MAIN RESULTS: Cerebral perfusion pressure index (ICA/CCA pressure ratio...

  6. Absence of vasoactive peptide release from brain to cerebral circulation during onset of migraine with aura

    DEFF Research Database (Denmark)

    Friberg, L; Olesen, J; Olsen, T S

    1994-01-01

    In eight patients carotid angiography was required for evaluation of transient neurological attacks. Cerebral blood flow results, angiography and clinical observations subsequently suggested the diagnosis of migraine. We measured plasma concentrations of substance P(SP), neuropeptide Y (NPY), cal...

  7. Sex differences in cerebral venous thrombosis: A systematic analysis of a shift over time

    NARCIS (Netherlands)

    Zuurbier, Susanna M.; Middeldorp, Saskia; Stam, Jan; Coutinho, Jonathan M.

    2016-01-01

    In contemporary studies, cerebral venous thrombosis is three times more common in adult women than in men. To study the change in sex ratio over time in cerebral venous thrombosis. We systematically reviewed the literature. Any type of study with at least 40 patients with cerebral venous thrombosis

  8. Quantification of extra-cerebral and cerebral hemoglobin concentrations during physical exercise using time-domain near infrared spectroscopy.

    Science.gov (United States)

    Auger, Héloïse; Bherer, Louis; Boucher, Étienne; Hoge, Richard; Lesage, Frédéric; Dehaes, Mathieu

    2016-10-01

    Fitness is known to have beneficial effects on brain anatomy and function. However, the understanding of mechanisms underlying immediate and long-term neurophysiological changes due to exercise is currently incomplete due to the lack of tools to investigate brain function during physical activity. In this study, we used time-domain near infrared spectroscopy (TD-NIRS) to quantify and discriminate extra-cerebral and cerebral hemoglobin concentrations and oxygen saturation ( SO 2 ) in young adults at rest and during incremental intensity exercise. In extra-cerebral tissue, an increase in deoxy-hemoglobin ( HbR ) and a decrease in SO 2 were observed while only cerebral HbR increased at high intensity exercise. Results in extra-cerebral tissue are consistent with thermoregulatory mechanisms to dissipate excess heat through skin blood flow, while cerebral changes are in agreement with cerebral blood flow ( CBF ) redistribution mechanisms to meet oxygen demand in activated regions during exercise. No significant difference was observed in oxy- ( HbO 2 ) and total hemoglobin ( HbT ). In addition HbO 2 , HbR and HbT increased with subject's peak power output (equivalent to the maximum oxygen volume consumption; VO 2 peak) supporting previous observations of increased total mass of red blood cells in trained individuals. Our results also revealed known gender differences with higher hemoglobin in men. Our approach in quantifying both extra-cerebral and cerebral absolute hemoglobin during exercise may help to better interpret past and future continuous-wave NIRS studies that are prone to extra-cerebral contamination and allow a better understanding of acute cerebral changes due to physical exercise.

  9. Usefulness of time-resolved projection MRA on evaluation of hemodynamics in cerebral occlusive diseases

    International Nuclear Information System (INIS)

    Oka, Yoshihisa; Kusunoki, Katsusuke; Nochide, Ichiro; Igase, Keiji; Harada, Hironobu; Sadamoto, Kazuhiko; Nagasawa, Kiyoshi

    2001-01-01

    The usefulness for evaluation of cerebral hemodynamics using time-resolved projection MRA was studied in normal volunteers and patients of cerebrovascular diseases. Six normal volunteers and ten patients with cerebrovascular occlusive diseases including 6 of IC occlusion and 4 of post EC/IC bypass surgery underwent time-resolved projection MRA on a 1.5 T clinical MRI system. Projection angiograms are acquired with 2D-fast SPGR sequence with a time resolution of approximately one image per second, 40 images being acquired consecutively before and after bolus injection Gd-DTPA. And all images were calculated by complex subtraction from the background mask in a work station. In normal volunteers, the quality of images of time-resolved projection MRA was satisfactory. The arteries from internal carotid artery through M2 segment of middle cerebral artery and all major venous systems were well portrayed. In 4 cases of IC occlusion who were assessed the collateral flow through the anterior communicating artery and posterior communicating artery, there were delayed to demonstrate the ipsilateral MCA. However, in 2 cases of IC occlusion that were assessed the collateral flow through leptomeningeal anastomosis, ipsilateral MCA and collateral circulation were not demonstrated. In all patients of post EC/IC bypass surgery, the patency of EC/IC bypass could be evaluated as properly with time-resolved projection MRA as 3D-TOF MRA. Although the temporal and spatial resolutions are insufficient, time-resolved projection MRA was power-full non-invasive method to evaluate the cerebral hemodynamics vis the basal communicating arteries in IC occlusion and identify the patency of EC/IC bypass. (author)

  10. Effects on cerebral circulation of decimeter wave therapy and variable magnetic field in patients with hemiparesis of vascular and traumatic origin

    Energy Technology Data Exchange (ETDEWEB)

    Strelkova, N.I.; Gavrilkov, A.T.; Dyuzhilova, N.F.; Strel' tsova, Ye.N.

    1981-08-01

    Both the artherosclerotic process in the case of cerebrovascular accident and cerebral trauma lead to impairment of cerebral hemodynamics, blood and spinal fluid circulation, macroscopic and microscopic disturbances. Electromagnetic waves in the decimeter range (decimeter waves - DMW) and a variable magnetic field (VMF) were used to treat these processes. Treatment was delivered directly to the region of the cerebral lesion, on the basis of the penetrating capacity of DMW and VMF to a relatively great depth (7 to 9 and 4 to 7 cm, respectively). Results of these treatments are discussed.

  11. Quantification of extra-cerebral and cerebral hemoglobin concentrations during physical exercise using time-domain near infrared spectroscopy

    OpenAIRE

    Auger, Héloïse; Bherer, Louis; Boucher, Étienne; Hoge, Richard; Lesage, Frédéric; Dehaes, Mathieu

    2016-01-01

    Fitness is known to have beneficial effects on brain anatomy and function. However, the understanding of mechanisms underlying immediate and long-term neurophysiological changes due to exercise is currently incomplete due to the lack of tools to investigate brain function during physical activity. In this study, we used time-domain near infrared spectroscopy (TD-NIRS) to quantify and discriminate extra-cerebral and cerebral hemoglobin concentrations and oxygen saturation (SO2) in young adults...

  12. The cerebral collateral circulation: Relevance to pathophysiology and treatment of stroke.

    Science.gov (United States)

    Ginsberg, Myron D

    2017-08-09

    The brain's collateral circulation consists of arterial anastomotic channels capable of providing nutrient perfusion to brain regions whose normal sources of flow have become compromised, as occurs in acute ischemic stroke. Modern CT-based neuroimaging is capable of providing detailed information as to collateral extent and sufficiency and is complemented by magnetic resonance-based methods. In the present era of standard-of-care IV thrombolysis for acute ischemic stroke, and following the recent therapeutic successes of randomized clinical trials of acute endovascular intervention, the sufficiency of the collateral circulation has been convincingly established as a key factor influencing the likelihood of successful reperfusion and favorable clinical outcome. This article reviews the features of the brain's collateral circulation; methods for its evaluation in the acute clinical setting; the relevance of collateral circulation to prognosis in acute ischemic stroke; the specific insights into the collateral circulation learned from recent trials of endovascular intervention; and the major influence of genetic factors. Finally, we emphasize the need to develop therapeutic approaches to augment collateral perfusion as an adjunctive strategy to be employed along with, or prior to, thrombolysis and endovascular interventions, and we highlight the possible potential of inhaled nitric oxide, albumin, and other approaches. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. EEG indices in patients with high risk of ischemic stroke as predictors of initial disturbed cerebral circulation

    Directory of Open Access Journals (Sweden)

    N. A. Isaeva

    2014-01-01

    Full Text Available Abnormal changes were detected in EEG in patients with high risk of ischemic stroke (higher level than in the population. These changes show the disturbances in forming mechanisms of functional condition of cerebrum during the calm wakeful period. Changes were represented by: the registration of EEG IV- type (the E.A. Zhirmunsky type which was characterized by disorganization of alpha activity and of slow waves; the instability of pattern during the record of background activity; the paroxysmal activity in form of flashes of the bilateral synchronized waves; the strengthening of low-frequency and high-amplitude β-activity. Revealed changes in EEG show the presence of initial disturbed cerebral circulation and can be recommended as predictors of these disturbances.

  14. Impact of treatment with melatonin on cerebral circulation in old rats

    Science.gov (United States)

    Dupuis, François; Régrigny, Olivier; Atkinson, Jeffrey; Limiñana, Patrick; Delagrange, Philippe; Scalbert, Elizabeth; Chillon, Jean-Marc

    2004-01-01

    Melatonin deprival in young rats induces alterations in cerebral arteriolar wall similar to those observed during aging: atrophy and a decrease in distensibility. In this study, we examined the effects of melatonin treatment on cerebral arteriolar structure and distensibility and on the lower limit of cerebral blood flow autoregulation (LLCBF) in old rats. We measured cerebral blood flow (arbitrary unit, laser Doppler, open skull preparation) prior to and during stepwise hypotension (SH) in adult (12/13 months) and old (24/25 months) IcoWI and WAG/Rij male rats. Old rats were untreated or treated for 3 months with melatonin (0.39 (IcoWi) and 0.44 (Wag/Rij) mg kg−1 day−1, drinking water). Stress–strain relationships were determined using cross-sectional area (CSA, μm2, histometry) and values of arteriolar internal diameter (μm) obtained during a second SH following arteriolar deactivation (EDTA, 67 mmol l−1). Aging induced (a) atrophy of the arteriolar wall in IcoWI (616±20 vs 500±27 μm2, P<0.05) but not in WAG/Rij rats (328±25 vs 341±20 μm2), (b) a decrease in arteriolar wall distensibility and (c) an increase in the LLCBF in both strains (67±10 mmHg in 12-month-old vs 95±6 mmHg in 24-month-old IcoWi, P<0.05 and 53±2 mmHg in 13-month-old vs 67±6 mmHg in 25-month-old WAG/Rij). Melatonin treatment induced in IcoWI and WAG/Rij rats (a) hypertrophy of the arteriolar wall (643±34 and 435±25 μm2, respectively), (b) an increase in arteriolar wall distensibility and (c) a decrease in the LLCBF (64±6 and 45±4 mmHg, respectively). Melatonin treatment of old rats induced hypertrophy of the arteriolar wall, prevented the age-linked decrease in cerebral arteriolar distensibility and decreased the LLCBF. PMID:14718260

  15. Regulation of cerebral circulation in spontaneous hypertension. Abstract. [Intraarterial xanon-133 technique]. Regulacja krazenia mozgowego krwi w genetycznie uwarunkowanym nadcisnieniu tetniczym (streszczenie pracy habilitacyjnej)

    Energy Technology Data Exchange (ETDEWEB)

    Kozniewska-Kolodziejska, E. (Akademia Medyczna, Warsaw (Poland))

    1991-01-01

    The study was undertaken in order to determine global cerebral blood flow (intraarterial xenon-133 technique), cerebral oxygen utilization and cerebrovascular resistance and to estimate cerebrocortical microcirculation (Clark-type surface microelectrodes, corrosion casts) during normo- and hypoxemia in normotensive, spontaneously hypertensive stroke-resistant and stroke-prone rats. The reactivity of cerebral circulation to the changes in the arterial partial pressure of carbon dioxide and to calcium channel blockade was also determined. The results of the study suggest that cerebrovascular resistance in spontaneously hypertensive rats under resting conditions depends, to a great extend, upon the increase of the permeability of cerebral blood vessel to calcium ions and upon the ratification of microvascular bed. Cerebral blood flow in spontaneously hypertensive rats is maintained at a normotensive level during normoxia and normocapnia. The reactivity of cerebral circulation to moderate changes of the arterial partial pressure of oxygen and carbon dioxide is well preserved in both strains of hypertensive rats in comparison with normotensive ones, but is diminished during severe hypocapnia. (author).

  16. Increase in cerebral oxygenation during advanced life support in out-of-hospital patients is associated with return of spontaneous circulation.

    Science.gov (United States)

    Genbrugge, Cornelia; Meex, Ingrid; Boer, Willem; Jans, Frank; Heylen, René; Ferdinande, Bert; Dens, Jo; De Deyne, Cathy

    2015-03-24

    By maintaining sufficient cerebral blood flow and oxygenation, the goal of cardiopulmonary resuscitation (CPR) is to preserve the pre-arrest neurological state. To date, cerebral monitoring abilities during CPR have been limited. Therefore, we investigated the time-course of cerebral oxygen saturation values (rSO₂) during advanced life support in out-of-hospital cardiac arrest. Our primary aim was to compare rSO₂ values during advanced life support from patients with return of spontaneous circulation (ROSC) to patients who did not achieve ROSC. We performed an observational study to measure rSO₂ using Equanox (Nonin, Plymouth, MI) from the start of advanced life support in the pre-hospital setting. rSO₂ of 49 consecutive out-of-hospital cardiac arrest patients were analyzed. The total increase from initial rSO₂ value until two minutes before ROSC or end of advanced life support efforts was significantly larger in the group with ROSC 16% (9 to 36) compared to the patients without ROSC 10% (4 to 15) (P = 0.02). Mean rSO₂ from the start of measurement until two minutes before ROSC or until termination of advanced life support was higher in patients with ROSC than in those without, namely 39% ± 7 and 31% ± 4 (P = 0.05) respectively. During pre-hospital advanced life support, higher increases in rSO₂ are observed in patients attaining ROSC, even before ROSC was clinically determined. Our findings suggest that rSO₂ could be used in the future to guide patient tailored treatment during cardiac arrest and could therefore be a surrogate marker of the systemic oxygenation state of the patient.

  17. Influence exerted by risk factors of space and erath weather on frequency of emergency calls from patients with acute cerebral circulation disorders

    Directory of Open Access Journals (Sweden)

    V.A. Belyaeva

    2017-12-01

    Full Text Available High morbidity with cardiovascular pathology increases loads on a public healthcare system and is not only social but also an economic problem. To optimize cardiovascular pathology prevention, it is necessary to thoroughly analyze risk factors which cause its occurrence. Our research goal was to examine a dynamics of acute cerebral circulation disorders depending on meteorological factors and heliofactors allowing for a seasonal component. We performed a retrospective analysis of morbidity with acute cerebral circulation disorders in winter, spring, and summer in 2012 on the basis of the archives obtained from an emergency station in Vladikavkaz. We analyzed 509 cases of the disease (294 women and 215 men. On the basis of our analysis results we assessed influence exerted by external factors on frequency of applications to emergency from patients with acute cerebral circulation disorders. We analyzed meteorological factors and heliofactors and their derivatives: average daily temperature, air pressure, relative humidity, wind speed, cloud coverage, weather pathogenicity, Sun radiation flux density at a wave length equal to 10.7, and a number of sunspots. We detected that in winter negative influence was exerted by temperature; there was also a multi-factor dependence between frequency of acute cerebral circulation disorders and such predictors as temperature pathogenicity index and speed of changes in Sun radiation flux density during a day (Rmulti = 0.50; R2 = 0.25. Drastic temperature fluctuations make for increase in morbidity in spring. Morbidity cases frequency in women in this period correlates not only with temperature pathogenicity index but also with pathogenicity index of air pressure changes. Morbidity increase in summer is caused by simultaneous drop both in air pressure and relative humidity (Rmulti = 0.59; R2 = 0.35. Overall, correlation between external factors and morbidity with acute cerebral circulation disorder has seasonal

  18. Assessment of cerebral circulation in normal fetuses by three-dimensional power Doppler ultrasonography

    International Nuclear Information System (INIS)

    Milani, Hérbene José Figuinha; Sá Barreto, Enoch Quinderé de; Araujo Júnior, Edward; Haratz, Karina Krajden; Rolo, Liliam Cristine; Nardozza, Luciano Marcondes Machado; Moron, Antonio Fernandes

    2012-01-01

    Objective: To assess the three-dimensional power Doppler ultrasonography (3D power Doppler) vascular indices in the middle cerebral artery (MCA), anterior cerebral artery (ACA) and posterior cerebral artery (PCA) territories. Methods: A cross-sectional study was carried out on 111 normal pregnancies between 26 and 34 weeks. The MCA, ACA and PCA territories closest to the transducer were scanned and volumes were calculated by using the VOCAL (Virtual Organ Computer-aided Analysis) program. The 3D power Doppler indices – vascularization index (VI), flow index (FI) and vascularization-flow index (VFI) were calculated. Scatter graphs, Pearson correlation coefficients (r) and linear regression models were used. Results: Only the FI-MCA (r = 0.38 and p < 0.001), VFI-MCA (r = 0.23 and p = 0.016) and FI-PCA (r = 0.191 and p = 0.040) had a low correlation with gestational age. The other 3D power Doppler indices VI-MCA (r = 0.153 and p = 0.150), VI-ACA (r = 0.105 and p = 0.271), FI-ACA (r = 0.154 and p = 0.106), VFI-ACA (r = 0.134 and p = 0.161), VI-PCA (r = 0.105 and p = 0.270) and VFI-PCA (r = 0.126 and p = 0.180) showed no statistically significant correlation with gestational. Conclusion: It was observed a low correlation between gestational age and the FI-MCA, VFI-MCA and FI-PCA.

  19. Experimental microangiography for measuring cerebral blood circulation following local cold stroke

    Energy Technology Data Exchange (ETDEWEB)

    Ruttmann, G

    1982-01-01

    In 54 female Wistar rats the exposed brain was right-parietally traumatised; cerebral perfusion of two anatomically different brain sections was angiographically imaged and densitometrically evaluated at various instants. The observation period ranged between 1 and 168 hours after the local cold stroke had been applied. Whereas in the telencephal section situated beyond the direct zone of lesion a maximum perfusion difference between the two hemispheres occurred already 1 hour after the animal had been traumatised, a maximum of perfusion difference was observed 6 hours after traumatisation in the diencephalic section situated directly across the site of the cold lesion. Within the first posttraumatic hours the total cerebral perfusion rapidly decreased. The minimum was reached 24 hours after traumatisation. Then it increased again and on the 7th posttraumatic day the perfusion level reached that of the control group. The tendencies of perfusion behaviour differing from one another, which were observed in both hemispheres, followed the course of the total perfusion. The decrease of perfusion occurring during the first hours after traumatisation is provoked by the compressive effect due to the expanding edema. This is principally indicated by the acute hyperperfusion during the first hours to be observed in the telencephalic section. The different velocities at which the hemispheres recover in the diencephalic section must be attributed to metabolic and hypoxic components. The incomplete recovery of perfusion in the injured hemisphere after 7 days may be due to the glial reaction.

  20. Cerebral venous angiomas

    International Nuclear Information System (INIS)

    Agnoli, A.L.; Hildebrandt, G.

    1985-01-01

    Clinical symptoms and radiological signs in 15 patients with cerebral venous malformations are presented and the diagnostic problems discussed. The circulation time in combination with cerebral malformations and angiomas of the scalp are described. CT findings in cases of venous malformations of the brain stem are evaluated. Spot-like enhancement, as well as sharply demarcated round shaped enhancement are characteristic for venous angiomas. Cavernous angiomas usually present as homogenous or inhomogenous round shaped enhanced areas. (Author)

  1. Portable real time analysis system for regional cerebral blood flow

    International Nuclear Information System (INIS)

    Tiernan, T.; Entine, G.; Stump, D.A.; Prough, D.S.

    1988-01-01

    A very portable, regional cerebral blood flow (rCBF) analysis instrument system suitable for use in the operating theater during surgery is under development. Cadmium telluride (CdTe) solid state radiation detectors, an 8086 based data acquisition and communications module and a DEC Microvax computer are used so that the instrument is very compact, yet has the computational power to provide real time data analysis in the clinical environment. The instrument is currently being used at Bowman Gray School of Medicine to study rCBF during cardiopulmonary bypass surgery (CPB). Preliminary studies indicate that monitoring rCBF during this surgical procedure may provide insights into the mechanism that causes a significant fraction of these patients to suffer post operative neuropsychological deficit

  2. Focal cerebral vasculitis associated with circulating immune complexes and brain irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Groothuis, D.R.; Mikhael, M.A.

    1986-06-01

    In this report we describe a patient with a benign glioma treated with surgery and radiation. After a period of stability he developed subacute bacterial endocarditis, and deteriorated neurologically. Computed tomographic scans did not show recurrent tumor. An angiogram showed vasculitis restricted to the previously irradiated area. Secondary to subacute bacterial endocarditis was the presence of high levels of circulating immune complexes. His neurological status was unchanged after antibiotics, but improved after treatment with dexamethasone. We interpret the clinical course as an immune-complex-mediated vasculitis superimposed on a subclinical radiation vasculitis. This case supports the hypothesis that immune mechanisms may be involved in delayed radiation injury to the nervous system.

  3. Focal cerebral vasculitis associated with circulating immune complexes and brain irradiation

    International Nuclear Information System (INIS)

    Groothuis, D.R.; Mikhael, M.A.

    1986-01-01

    In this report we describe a patient with a benign glioma treated with surgery and radiation. After a period of stability he developed subacute bacterial endocarditis, and deteriorated neurologically. Computed tomographic scans did not show recurrent tumor. An angiogram showed vasculitis restricted to the previously irradiated area. Secondary to subacute bacterial endocarditis was the presence of high levels of circulating immune complexes. His neurological status was unchanged after antibiotics, but improved after treatment with dexamethasone. We interpret the clinical course as an immune-complex-mediated vasculitis superimposed on a subclinical radiation vasculitis. This case supports the hypothesis that immune mechanisms may be involved in delayed radiation injury to the nervous system

  4. Study of cerebral vascular diseases with radioisotopes in cerebral atherosclerotical subjects and/for subjects with sequelae of cerebral stroke, before and after use of the association piracetam-dihydroergotoxine

    International Nuclear Information System (INIS)

    Lara, P.F.; Ferreira, A.; Paulillo, L.F.; Cukierman, M.

    1985-01-01

    Twently subjects with cerebral sclerosis and/or sequelas of cerebral stroke were studied, before and after use of piracetam-dihydroergotoxine. We performed the complete hemispheric cerebral blood flow and cerebral scintigraphy, beyond clinical and neurological examination. Scintigraphies were unchanged. Cerebral circulation times, or both hemispheres, diminished. This occurred, probably, in relation with metabolic effects of both pharmaceutical drugs. The alpha sympatolytic and modulatory effects of dihydroergotoxine should be considered. (author) [pt

  5. Observed variations in U.S. frost timing linked to atmospheric circulation patterns.

    Science.gov (United States)

    Strong, Courtenay; McCabe, Gregory J

    2017-05-23

    Several studies document lengthening of the frost-free season within the conterminous United States (U.S.) over the past century, and report trends in spring and fall frost timing that could stem from hemispheric warming. In the absence of warming, theory and case studies link anomalous frost timing to atmospheric circulation anomalies. However, recent efforts to relate a century of observed changes in U.S. frost timing to various atmospheric circulations yielded only modest correlations, leaving the relative importance of circulation and warming unclear. Here, we objectively partition the U.S. into four regions and uncover atmospheric circulations that account for 25-48% of spring and fall-frost timing. These circulations appear responsive to historical warming, and they consistently account for more frost timing variability than hemispheric or regional temperature indices. Reliable projections of future variations in growing season length depend on the fidelity of these circulation patterns in global climate models.

  6. Multi-infarct dementia and Alzheimer disease, contribution of cerebral circulation ultrasonography to pathogenesis and differential diagnosis. Value of microembolisation.

    Science.gov (United States)

    Pancak, Jaroslav; Wagnerova, Helena; Škultéty Szárazová, Andrea; Blaho, Andrej; Durovsky, Ondrej; Durovska, Judita

    2016-01-01

    Dementias are one of the most serious health and socioeconomic issues. Multi-infarct dementia (MID) and Alzheimer´s type dementia (AD) exhibit differences in cerebrovascular blood flow velocity profiles and in presence of microemboli, detected by transcranial Doppler sonography. A group of 77 persons was divided into 4 subgroups: 1. subgroup of patients with MID (n=19; 10 male and 9 female, mean age was 74.32±8.30 years); 2. subgroup of patients with AD (n=19; 11 male and 8 female, mean age was 70.37±87.85 years); 3. subgroup of patients with hypertension (n=19; 11 male and 8 female, age adjusted) and 4. sex and age adjusted control group (CG) of 20 persons without hypertension or other serious risk factors. The duplex ultrasonographic examination of extracranial and intracranial circulation was preceded by neurologic, neuropsychological and psychiatric examination. The presence of microemboli was determined using Multi Dop X2 device (maker DWL), 60 minutes monitoring. All patients underwent brain computer tomography (CT) or magnetic resonance imaging (MRI). We found significantly higher incidence (68.4%, p=0.5267) of asymptomatic microemboli in ACM in the group of patients with MID compared to the AD group, the group of patients with hypertension and CG. The occurrence of "asymptomatic" emboli in the middle cerebral artery in patients with multi-infarct dementia is higher in the current study. Although these microemboli do not cause immediate symptoms, the evidence suggests, that they may be a risk factor for cognitive impairment, especially for multi-infarct dementia.

  7. Time Course of Changes in Extravascular Lung Water Index, Intracranial and Cerebral Perfusion Pressures in Acute Cerebral Circulatory Disorders

    Directory of Open Access Journals (Sweden)

    Yu. A. Churlyaev

    2009-01-01

    Full Text Available Objective: to study the time course of changes in extravascular lung water index (ELWI and intracranial and cerebral perfusion pressures (ICP and CPP and to determine their possible relationships in acute cerebral circulatory disorders (ACCD. Subject and methods. ELWI, pulmonary vascular permeability index (PVPI, ICP, CPP, and central hemodynamics were studied by transpulmonary thermodilution and current X-ray studies were conducted in 18 patients on days 1, 3, 5, and 7 of ACCD. Results. Examinations revealed a supratentorial dislocation of the brain in 6 persons; its subtento-rial dislocation was found in 1 case; supra- and subtentorial dislocations were seen in 6. In patients, ELWI and PVPI increased from days 1 and 5, respectively. The high baseline ICP increased over time. CPP remained unchanged. Preserved left ventricular contractility, enhanced myocardial one, a significant direct correlation between ELWI and PVPI, as well as their increase confirmed that the noncardiogenic genesis was responsible for increased ELWI. A direct significant correlation was found between ICP and ELWI, ICP and PVPI. Against this background, acute respiratory distress syndrome developed in 14 patients with pneumonia evolving in its presence in 7 patients. Conclusion. In ACCD, ELWI increases in the first 24 hours of the acute period. One of its causes is, along with others, primary and/or secondary damage to the brainstem structures with elevated ICP and progressive brain dislocation. The determination of ICP, unlike CPP, is crucial in the diagnosis and treatment of primary/secondary brain injuries and in prognosis. Key words: acute cerebral circulatory disorder, extravascular lung fluid, pulmonary vascular permeability, intracranial pressure, cerebral perfusion pressure, acute respiratory distress syndrome.

  8. Detection of cerebral hemorrhage in rabbits by time-difference magnetic inductive phase shift spectroscopy.

    Directory of Open Access Journals (Sweden)

    Wencai Pan

    Full Text Available Cerebral hemorrhage, a difficult issue in clinical practice, is often detected and studied with computed tomography (CT, magnetic resonance imaging (MRI, and positron emission tomography (PET. However, these expensive devices are not readily available in economically underdeveloped regions, and hence are unable to provide bedside and emergency on-site monitoring. The magnetic inductive phase shift (MIPS is an emerging technology that may become a new tool to detect cerebral hemorrhage and to serve as an inexpensive partial substitute to medical imaging. In order to study a wider band of cerebral hemorrhage MIPS and to provide more useful information for measuring cerebral hemorrhage, we established a cerebral hemorrhage magnetic induction phase shift spectroscopy (MIPSS detection system. Thirteen rabbits with five cerebral hemorrhage states were studied using a single coil-coil within a 1 MHz-200 MHz frequency range in linear sweep. A feature band (FB with the highest detection sensitivity and the greatest stability was selected for further analysis and processing. In addition, a maximum conductivity cerebrospinal fluid (CSF MRI was performed to verify and interpret the MIPSS result. The average phase shift change induced by a 3 ml injection of autologous blood under FB was -7.7503° ± 1.4204°, which was considerably larger than our previous work. Data analysis with a non-parametric statistical Friedman M test showed that in the FB, MIPSS could distinguish the five states of cerebral hemorrhage in rabbits, with a statistical significance of p<0.05. A B-F distribution profile was designed according to the MIPSS under FB that can provide instantaneous diagnostic information about the cerebral hemorrhage severity from a single set of measurements. The results illustrate that the MIPSS detection method is able to provide a new possibility for real-time monitoring and diagnosis of the severity of cerebral hemorrhage.

  9. Time dependency of local cerebral blood flow measurements caused by regional variations in tissue transit time

    International Nuclear Information System (INIS)

    Lear, J.L.; Kasliwal, R.; Feyerabend, A.

    1990-01-01

    Calculated values of local cerebral blood flow (LCBF) using the diffusible tracer model are assumed to be independent of time as long as experiments are brief enough to prevent tissue saturation. This paper investigates the effects of CTT variation on LCBF measurements. Using double-label quantitative digital autoradiography, we compared iodoantipyrine (IAP)-based LCBF measurements obtained with tracer infusions of different lengths of time. Lightly anesthetized rats were given simultaneous ramp infusions of C-14 IAP (45 seconds) and I-123 IAP (15 seconds) and immediately sacrificed. Two autoradiograms of each brain section, one representing I-123 and the other representing C-14, were produced, digitized, and converted into images of LCBF based on the 15- and 45-second infusion periods. The LCBF image pairs were compared on a pixel-by-pixel basis

  10. Detection of Cerebral Hemorrhage in Rabbits by Time-Difference Magnetic Inductive Phase Shift Spectroscopy

    Science.gov (United States)

    Pan, Wencai; Yan, Qingguang; Qin, Mingxin; Jin, Gui; Sun, Jian; Ning, Xu; Zhuang, Wei; Peng, Bin; Li, Gen

    2015-01-01

    Cerebral hemorrhage, a difficult issue in clinical practice, is often detected and studied with computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET). However, these expensive devices are not readily available in economically underdeveloped regions, and hence are unable to provide bedside and emergency on-site monitoring. The magnetic inductive phase shift (MIPS) is an emerging technology that may become a new tool to detect cerebral hemorrhage and to serve as an inexpensive partial substitute to medical imaging. In order to study a wider band of cerebral hemorrhage MIPS and to provide more useful information for measuring cerebral hemorrhage, we established a cerebral hemorrhage magnetic induction phase shift spectroscopy (MIPSS) detection system. Thirteen rabbits with five cerebral hemorrhage states were studied using a single coil-coil within a 1 MHz-200 MHz frequency range in linear sweep. A feature band (FB) with the highest detection sensitivity and the greatest stability was selected for further analysis and processing. In addition, a maximum conductivity cerebrospinal fluid (CSF) MRI was performed to verify and interpret the MIPSS result. The average phase shift change induced by a 3 ml injection of autologous blood under FB was -7.7503° ± 1.4204°, which was considerably larger than our previous work. Data analysis with a non-parametric statistical Friedman M test showed that in the FB, MIPSS could distinguish the five states of cerebral hemorrhage in rabbits, with a statistical significance of phemorrhage severity from a single set of measurements. The results illustrate that the MIPSS detection method is able to provide a new possibility for real-time monitoring and diagnosis of the severity of cerebral hemorrhage. PMID:26001112

  11. Evaluation of cerebral intravascular blood flow by time density curve study of intravenous digital subtraction angiography

    Energy Technology Data Exchange (ETDEWEB)

    Imamura, Toru; Kogure, Kyuya (Tohoku Univ., Sendai (Japan). School of Medicine); Sekine, Teiko; Satoh, Kei; Endoh, Minoru; Tsuburaya, Kenji; Hoshi, Akihiko

    1992-01-01

    Time density curve (TDC) can be reconstructed from the data of intravenous digital subtraction angiography (IVDSA). We evaluated peak time (PT) and modal transit time (MOTT) of the TDC as the probable indicator of cerebral intravascular blood flow. Cerebral IVDSA and single photon emission CT (SPECT) were performed on 12 patients with ischemic cerebrovascular disease, which consisted of 3 internal carotid artery (ICA) occlusions, one middle cerebral artery (MCA) occlusion, one anterior cerebral artery (ACA) branch occlusion and 7 lacunar infarctions. We classified former 4 patients as occlusion group and latter 8 as reference group. In 3 patients (2 ICA and one MCA occlusions), SPECT study revealed definite hypoaccumulation in the MCA territory of occlusive side. Two regions of interest (ROI) were placed on the territories of right and left middle cerebral arteries in the frontal view of cerebral IVDSA. Digital data processor fitted {gamma} curve to the TDC of each ROI, and calculated PT and MOTT. The absolute lateralities of PT and MOTT of MCA territory was significantly (p<0.05) larger in occlusion group than reference group. Patients with hypoaccumulation in SPECT had significantly (p<0.02) larger laterality of MOTT than patients with isoaccumulation. One ICA occluded patient without hypoaccumulation in corresponding MCA territory had relatively small laterality of MOTT similar to the patients of ACA branch occlusion and lacunar infarction. These results suggest that PT and MOTT are possible to detect the laterality of the intravascular blood flow in MCA territories caused by major artery occlusion. Cerebral TDC study of IVDSA may be useful in some clinical therapeutic situations such as hemodilution or intra-arterial thrombolysis, and worth further clinical evaluation. (author).

  12. Intra-arterial thrombolysis using rt-PA in patients with acute stroke due to vessel occlusion of anterior and/or posterior cerebral circulation

    Energy Technology Data Exchange (ETDEWEB)

    Tountopoulou, Argyro; Ahl, Bjoern; Weissenborn, Karin [Hannover Medical School, Department of Neurology and Clinical Neurophysiology, Hannover (Germany); Becker, Hartmut; Goetz, Friedrich [Hannover Medical School, Department of Neuroradiology, Hannover (Germany)

    2008-01-15

    The aim of our study was to evaluate the safety and efficacy of intra-arterial (IA) thrombolysis using recombinant tissue plasminogen activator (rt-PA) in patients with acute stroke due to occlusion in the anterior or posterior circulation. We retrospectively analyzed the clinical and radiological data of 88 consecutive patients with acute ischemic stroke who underwent emergency cerebral angiography for the purpose of subsequent IA thrombolysis. The neurological deficit on admission and discharge was graded using the National Institutes of Health Stroke Scale (NIHSS) score. Baseline computer tomography (CT) scans were examined for any signs indicative of cerebral ischemia. The angiographic findings were classified according to the Thrombolysis in Myocardial Infarction (TIMI) score for myocardial infarction. Follow-up CT scans were examined for hemorrhagic complication. Of the 88 patients who underwent IA thrombolysis, 63 presented with complete or partial arterial occlusion in the suspected perfusion area. In these 63 patients, the median NIHSS score dropped from 15 points on admission to 10 points at discharge. The recanalization rate was 52.6% for partial and complete reperfusion. In-hospital mortality was 20.6% (9.1% for carotid, 44.4% for basilar territory occlusion). Intracerebral bleeding (ICB) occurred in 38.6% of the patients with occlusion in the anterior circulation, resulting in these patients presenting a worse clinical outcome than those without ICB. Only minor extracranial bleedings occurred in 20.6% of patients. Patients with ICB had a significantly higher frequency of ischemic signs on the baseline CT scan. Occlusion of a cerebral artery is present in about 75% of the patients eligible for thrombolytic therapy. Intra-arterial thrombolysis using rt-PA in patients with acute ischemic stroke can achieve re-vascularization, although ICB remains the major risk factor affecting its efficacy. (orig.)

  13. Intra-arterial thrombolysis using rt-PA in patients with acute stroke due to vessel occlusion of anterior and/or posterior cerebral circulation

    International Nuclear Information System (INIS)

    Tountopoulou, Argyro; Ahl, Bjoern; Weissenborn, Karin; Becker, Hartmut; Goetz, Friedrich

    2008-01-01

    The aim of our study was to evaluate the safety and efficacy of intra-arterial (IA) thrombolysis using recombinant tissue plasminogen activator (rt-PA) in patients with acute stroke due to occlusion in the anterior or posterior circulation. We retrospectively analyzed the clinical and radiological data of 88 consecutive patients with acute ischemic stroke who underwent emergency cerebral angiography for the purpose of subsequent IA thrombolysis. The neurological deficit on admission and discharge was graded using the National Institutes of Health Stroke Scale (NIHSS) score. Baseline computer tomography (CT) scans were examined for any signs indicative of cerebral ischemia. The angiographic findings were classified according to the Thrombolysis in Myocardial Infarction (TIMI) score for myocardial infarction. Follow-up CT scans were examined for hemorrhagic complication. Of the 88 patients who underwent IA thrombolysis, 63 presented with complete or partial arterial occlusion in the suspected perfusion area. In these 63 patients, the median NIHSS score dropped from 15 points on admission to 10 points at discharge. The recanalization rate was 52.6% for partial and complete reperfusion. In-hospital mortality was 20.6% (9.1% for carotid, 44.4% for basilar territory occlusion). Intracerebral bleeding (ICB) occurred in 38.6% of the patients with occlusion in the anterior circulation, resulting in these patients presenting a worse clinical outcome than those without ICB. Only minor extracranial bleedings occurred in 20.6% of patients. Patients with ICB had a significantly higher frequency of ischemic signs on the baseline CT scan. Occlusion of a cerebral artery is present in about 75% of the patients eligible for thrombolytic therapy. Intra-arterial thrombolysis using rt-PA in patients with acute ischemic stroke can achieve re-vascularization, although ICB remains the major risk factor affecting its efficacy. (orig.)

  14. Cerebral Palsy

    Science.gov (United States)

    Cerebral palsy is a group of disorders that affect a person's ability to move and to maintain balance ... do not get worse over time. People with cerebral palsy may have difficulty walking. They may also have ...

  15. Control of the cerebral circulation and metabolism by the rostral ventrolateral medulla: Possible role in the cerebrovascular response to hypoxia

    International Nuclear Information System (INIS)

    Underwood, M.D.

    1988-01-01

    Neurons within the rostral ventrolateral medulla (RVL) corresponding to the location of adrenaline neurons of the C1 group (C1 area) maintain resting levels of arterial pressure (AP) and mediate the reflex cardiovascular responses to baro- and chemoreceptor activation and cerebral ischemia. The author therefore sought to determine whether neurons in the C1 area: (a) modulate regional cerebral blood flow (rCBF) and/or cerebral glucose utilization (rCGU), (b) participate in the maintenance of resting levels of CBF and CGU, and (c) mediate the CBF response to hypoxia. Rats were anesthetized, paralyzed and ventilated. The RVL was stimulated electrically or chemically, with kainic acid; lesions were placed electrolytically. rCBF was measured using 14-C-iodoantipyrine and rCGU with 14 C-2-deoxyglucose in 11 dissected brain regions

  16. A study of cerebral circulation in elderly patients with dementia using sup 123 I-IMP SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Arai, Hisayuki [Tokyo Medical Coll. (Japan)

    1991-03-01

    In order to elucidate the pathogenesis of senile dementia of Alzheimer type (SDAT) and multi-infarct dementia (MID), 18 age-matched controls, 22 SDAT cases, 10 MID cases, and 15 multiple infarction without dementia (MI) cases, totaling 65 cases, were enrolled into a study of cerebral blood flow using single photon emission CT (SPECT) with N-isopropyl-p-({sup 123}I)iodoamphetamine (IMP). The diagnosis of dementia was made based on the clinical history, findings of brain CT, MRI, and Hachinski's ischemic score. Lateral asymmetric perfusion was evaluated by using the asymmetry index (AI). Quantitative cerebral blood flow was analyzed by using the venous blood sampling method with IMP SPECT. Cerebral infarction, ischemic changes, and brain atrophy were diagnosed by CT and MRI. mCBF values were significantly lower in SDAT and MID than in those of controls, while rCBF values were lowest at the frontal lobes in MID and at the parietal lobes in SDAT. Hasegawa's dementia score was correlated with the rCBF at the frontal lobes in MID. In MID, there was a greater number of infarction, and atrophic changes were significantly remarkable, while the rCBF values were significantly lower at the frontal lobes compared to the MI group. Multi-variate analysis suggested that among the factors contributing to MID, brain atrophy was most relevant to dementia. In SDAT, rCBF values showed the most lateral asymmetry at the parietal lobes, the least, at the occipital lobes. The lateral asymmetry of the cerebral blood flow at the parietal lobes showed an association with clinical symptoms. There was a negative coefficiency between the cerebellum and the cerebral hemisphere in the evaluation of lateral asymmetry. These results suggest that rCBF estimation by IMP SPECT is useful in the differential diagnosis between MID and SDAT, and may also contribute to the classification of these two diseases. (author).

  17. Influence exerted by new pyrimidine derivatives on cerebral circulation auto-regulation and vasodilatating function of vessels endothelium in rats' brains under chronic hemic hypoxia

    Directory of Open Access Journals (Sweden)

    A.V. Voronkov

    2018-03-01

    Full Text Available Our research goal was to examine influences exerted by new pyrimidine derivatives coded as BL0 and BL2 on cerebral hemodynamics auto-regulation parameters and vasodilatating function of vessels endothelium as risk factors causing ischemic and hemorrhagic strokes under chronic hemic hypoxia. We performed an experiment on white Wistar rats to prove that endothelial dysfunction which evolves under chronic hemic hypoxia leads to disorders in endothelium-mediated mechanisms for cerebral circulation auto-regulation in rats. We modeled hypoxia in animals via granting them free access to 0.2 % sodium nitrite solution instead of ordinary drinking water. Endothelial dysfunction was confirmed as per disorders in vasodilatation and vasoconstriction reactions at intravenous introduction of acetyl choline (0.1 mg/kg and methyl ether hydrochloride nitro-L-arginine (10 mg/kg. Cerebral blood flow speed was measured with MM-D-K-Minimax v.2.1. ultrasound Doppler. We assessed cerebral circulation auto-regulation as per compression test results which allowed us to calculate overshoot coefficient and auto-regulation power. Examined pyrimidine derivatives and comparison preparations were introduced orally 60 minutes prior to taking readings. Mexidol doses were calculated on the basis of interspecific recalculation of a maximum daily dose for a man. Nicergoline dose was taken as a most effective one as per literature data. When new pyrimidine derivatives BL0 and BL2 are applied under chronic hemic hypoxia, it causes overshoot coefficient to grow authentically higher than in a negative control group but it doesn't exert any positive influence on collateral reserve parameter, namely auto-regulation power. BL0 and BL2 improve endothelium vasodilatating function at intravenous acetylcholine introduction (0.1 mg/kg and don't exert any influence on vasoconstricting function at L-NAME intravenous introduction (10 mg/kg. The examined substance BL0 has more apparent

  18. Real-time imaging of cerebral infarction in rabbits using electrical impedance tomography.

    Science.gov (United States)

    Yang, Bin; Shi, Xuetao; Dai, Meng; Xu, Canhua; You, Fushen; Fu, Feng; Liu, Ruigang; Dong, Xiuzhen

    2014-02-01

    To investigate the possible use of electrical impedance tomography (EIT) in monitoring focal cerebral infarction in a rabbit model. A model of focal cerebral infarction was established in eight New Zealand rabbits using a photochemical method without craniectomy. Focal cerebral infarction was confirmed by histopathological examination. Intracranial impedance variation was measured using 16 electrodes placed in a circle on the scalp. EIT images were obtained using a damped least-squares reconstruction algorithm. The average resistivity value (ARV) of the infarct region on EIT images was calculated to quantify relative resistivity changes. A symmetry index was calculated to evaluate the relative difference in resistivity between the two sides of the cerebrum. EIT images and ARV curves showed that impedance changes caused by cerebral infarction increased linearly with irradiation time. A difference in ARV was found between measurements taken before and after infarct induction. Focal cerebral infarction can be monitored by EIT in the proposed animal model. The results are sufficiently encouraging that the authors plan to extend this study to humans, after further technical improvements.

  19. Cerebral perfusion characteristics show differences in younger versus older children with sickle cell anaemia: Results from a multiple-inflow-time arterial spin labelling study.

    Science.gov (United States)

    Kawadler, Jamie M; Hales, Patrick W; Barker, Simon; Cox, Timothy C S; Kirkham, Fenella J; Clark, Chris A

    2018-03-30

    Sickle cell anaemia (SCA) is associated with chronic anaemia and oxygen desaturation, which elevate cerebral blood flow (CBF) and increase the risk of neurocognitive complications. Arterial spin labelling (ASL) provides a methodology for measuring CBF non-invasively; however, ASL techniques using only a single inflow time are not sufficient to fully characterize abnormal haemodynamic behaviour in SCA. This study investigated haemodynamic parameters from a multi-inflow-time ASL acquisition in younger (8-12 years) and older (13-18 years) children with SCA with and without silent cerebral infarction (SCI+/-) (n = 20 and 19 respectively, 6 and 4 SCI+ respectively) and healthy controls (n = 9 and 7 respectively). Compared with controls, CBF was elevated globally in both groups of patients. In the younger SCA patients, blood oxygen content was negatively correlated with CBF in the middle and posterior cerebral artery territories and significantly positively correlated with bolus arrival time (BAT) in the anterior and middle cerebral artery territories. In older children, SCA patients had significantly shorter BAT than healthy controls and there was a significant negative correlation between CBF and oxygen content only in the territory of the posterior cerebral artery, with a trend for a correlation in the anterior cerebral artery but no relationship for the middle cerebral artery territory. In the younger group, SCI+ patients had significantly higher CBF in the posterior cerebral artery territory (SCI+ mean = 92.78 ml/100 g/min; SCI- mean = 72.71 ml/100 g/min; F = 4.28, p = 0.04), but this no longer reached significance when two children with abnormal transcranial Doppler and one with haemoglobin SC disease were excluded, and there were no significant differences between patients with and without SCI in the older children. With age, there appears to be increasing disparity between patients and controls in terms of the relationship between CBF and oxygen

  20. Asphyxia-related risk factors and their timing in spastic cerebral palsy

    DEFF Research Database (Denmark)

    Nielsen, Lene F.; Schendel, Diana; Grove, Jakob

    2008-01-01

    Objective To investigate the association of asphyxia-related conditions (reducing blood flow or blood oxygen levels in the fetus) with spastic cerebral palsy (CP) considering different gestational age groups and the timing of risk. Design Population-based case-control study. Setting Danish Cerebral...... Palsy Register in eastern Denmark and Danish Medical Birth Register. Population or Sample 271 singletons with spastic CP and 217 singleton controls, frequency matched by gestational age group, born 1982-1990 in eastern Denmark. Methods Data were abstracted from medical records, and a priori asphyxia...

  1. Cerebral activation related to implicit sequence learning in a Double Serial Reaction Time task

    NARCIS (Netherlands)

    van der Graaf, FHCE; Maguire, RP; Leenders, KL; de Jong, BM

    2006-01-01

    Using functional magnetic resonance imaging (fMRI), we examined the distribution of cerebral activations related to implicitly learning a series of fixed stimulus-response combinations. In a novel - bimanual - variant of the Serial Reaction Time task (SRT), simultaneous finger movements of the two

  2. Gait Patterns in Twins with Cerebral Palsy: Similarities and Development over Time after Multilevel Surgery

    Science.gov (United States)

    van Drongelen, Stefan; Dreher, Thomas; Heitzmann, Daniel W. W.; Wolf, Sebastian I.

    2013-01-01

    To examine gait patterns and gait quality, 7 twins with cerebral palsy were measured preoperatively and after surgical intervention. The aim was to study differences and/or similarities in gait between twins, the influence of personal characteristics and birth conditions, and to describe the development of gait over time after single event…

  3. Cerebral venous and sinus thrombosis with cerebrospinal fluid circulation block after the first methotrexate administration by lumbar puncture

    International Nuclear Information System (INIS)

    Bienfait, H.P.; Gijtenbeek, J.M.M.; Bent, M.J. van; Bruin, H.G. de; Voogt, P.J.; Pillay, M.

    2002-01-01

    We report a patient treated for small lymphocytic lymphoma/leukemia with cerebral venous and sinus thrombosis (CVST) after lumbar puncture with intrathecal administration of methotrexate (MTX). He also developed a cerebrospinal fluid flow block. This is the first report of an association between lumbar puncture and intrathecally administered MTX and the development of CVST. Intrathecal treatment in this patient was discontinued and he was successfully treated with high-dose low-molecular-weight heparin subcutaneously. (orig.)

  4. Construction of a Cerebral Hemorrhage Test System Operated in Real-time

    Science.gov (United States)

    Li, Gen; Sun, Jian; Ma, Ke; Yan, Qingguang; Zheng, Xiaolin; Qin, Mingxin; Jin, Gui; Ning, Xu; Zhuang, Wei; Feng, Hua; Huang, Shiyuwei

    2017-02-01

    The real-time monitoring and evaluation of the severity and progression of cerebral hemorrhage is essential to its intensive care and its successful emergency treatment. Based on magnetic induction phase shift technology combined with a PCI data acquisition system and LabVIEW software, this study established a real-time monitoring system for cerebral hemorrhage. To test and evaluate the performance of the system, the authors performed resolution conductivity experiments, salted water simulation experiments and cerebral hemorrhage experiments in rabbits and found that when the conductivity difference was 0.73 S/m, the phase difference was 13.196°. The phase difference change value was positively proportional to the volume of saline water, and the conductivity value was positively related to the phase difference of liquid under the same volume conditions. After injecting 3 mL blood into six rabbits, the average change in the blood phase difference was -2.03783 ± 0.22505°, and it was positively proportional to the volume of blood, which was consistent with the theoretical results. The results show that the system can monitor the progressive development of cerebral hemorrhage in real-time and has the advantages of low cost, small size, high phase accuracy, and good clinical application potentiality.

  5. Nitrite and S-Nitrosohemoglobin Exchange Across the Human Cerebral and Femoral Circulation: Relationship to Basal and Exercise Blood Flow Responses to Hypoxia.

    Science.gov (United States)

    Bailey, Damian M; Rasmussen, Peter; Overgaard, Morten; Evans, Kevin A; Bohm, Aske M; Seifert, Thomas; Brassard, Patrice; Zaar, Morten; Nielsen, Henning B; Raven, Peter B; Secher, Niels H

    2017-01-10

    The mechanisms underlying red blood cell (RBC)-mediated hypoxic vasodilation remain controversial, with separate roles for nitrite () and S-nitrosohemoglobin (SNO-Hb) widely contested given their ability to transduce nitric oxide bioactivity within the microcirculation. To establish their relative contribution in vivo, we quantified arterial-venous concentration gradients across the human cerebral and femoral circulation at rest and during exercise, an ideal model system characterized by physiological extremes of O 2 tension and blood flow. Ten healthy participants (5 men, 5 women) aged 24±4 (mean±SD) years old were randomly assigned to a normoxic (21% O 2 ) and hypoxic (10% O 2 ) trial with measurements performed at rest and after 30 minutes of cycling at 70% of maximal power output in hypoxia and equivalent relative and absolute intensities in normoxia. Blood was sampled simultaneously from the brachial artery and internal jugular and femoral veins with plasma and RBC nitric oxide metabolites measured by tri-iodide reductive chemiluminescence. Blood flow was determined by transcranial Doppler ultrasound (cerebral blood flow) and constant infusion thermodilution (femoral blood flow) with net exchange calculated via the Fick principle. Hypoxia was associated with a mild increase in both cerebral blood flow and femoral blood flow (Pflow during exercise (Pvenous; Parterial; P0.05). These findings suggest that hypoxia and, to a far greater extent, exercise independently promote arterial-venous delivery gradients of intravascular nitric oxide, with deoxyhemoglobin-mediated reduction identified as the dominant mechanism underlying hypoxic vasodilation. © 2016 American Heart Association, Inc.

  6. Cerebral Lactate Concentration in Neonatal Hypoxic-Ischemic Encephalopathy: In Relation to Time, Characteristic of Injury, and Serum Lactate Concentration

    Directory of Open Access Journals (Sweden)

    Tai-Wei Wu

    2018-05-01

    Full Text Available BackgroundCerebral lactate concentration can remain detectable in neonatal hypoxic-ischemic encephalopathy (HIE after hemodynamic stability. The temporal resolution of regional cerebral lactate concentration in relation to the severity or area of injury is unclear. Furthermore, the interplay between serum and cerebral lactate in neonatal HIE has not been well defined. The study aims to describe cerebral lactate concentration in neonatal HIE in relation to time, injury, and serum lactate.Design/methodsFifty-two newborns with HIE undergoing therapeutic hypothermia (TH were enrolled. Magnetic resonance imaging and spectroscopy (MRI + MR spectroscopy were performed during and after TH at 54.6 ± 15.0 and 156 ± 57.6 h of life, respectively. Severity and predominant pattern of injury was scored radiographically. Single-voxel 1H MR spectra were acquired using short-echo (35 ms PRESS sequence localized to the basal ganglia (BG, thalamus (Thal, gray matter (GM, and white matter. Cerebral lactate concentration was quantified by LCModel software. Serum and cerebral lactate concentrations were plotted based on age at time of measurement. Multiple comparisons of regional cerebral lactate concentration based on severity and predominant pattern of injury were performed. Spearman’s Rho was computed to determine correlation between serum lactate and cerebral lactate concentration at the respective regions of interest.ResultsOverall, serum lactate concentration decreased over time. Cerebral lactate concentration remained low for less severe injury and decreased over time for more severe injury. Cerebral lactate remained detectable even after TH. During TH, there was a significant higher concentration of cerebral lactate at the areas of injury and also when injury was more severe. However, these differences were no longer observed after TH. There was a weak correlation between serum lactate and cerebral lactate concentration at the BG (rs

  7. Characterisation of cerebral blood flow via determining the vascular mean transit time

    International Nuclear Information System (INIS)

    Lindner, P.; Thelen, M.

    1987-01-01

    By using a recently developed algorithm it is possible to quantify the dynamic information of a DSA sequence of the brain. The theory of algorithm allows to calculate vascular mean transit from time density curves. The algorithm minimizes the problems of densitometry with regard to 'quantitative DSA'. There is a strong correlation between vascular mean transit times and cerebral blood flow values, and therefore the results for mean transit times also correspond to the results obtained for cerebral blood flow. By computerized postprocessing of DSA-images it is possible to generate functional images of the brain with a spatial resolution that had not been attainable so far. The images represent the distribution pattern of reverse vascular mean transit times. The results from 36 patients with proven stenoses of the cervical vessels are reported. (orig.) [de

  8. Applying time-frequency analysis to assess cerebral autoregulation during hypercapnia.

    Directory of Open Access Journals (Sweden)

    Michał M Placek

    Full Text Available Classic methods for assessing cerebral autoregulation involve a transfer function analysis performed using the Fourier transform to quantify relationship between fluctuations in arterial blood pressure (ABP and cerebral blood flow velocity (CBFV. This approach usually assumes the signals and the system to be stationary. Such an presumption is restrictive and may lead to unreliable results. The aim of this study is to present an alternative method that accounts for intrinsic non-stationarity of cerebral autoregulation and the signals used for its assessment.Continuous recording of CBFV, ABP, ECG, and end-tidal CO2 were performed in 50 young volunteers during normocapnia and hypercapnia. Hypercapnia served as a surrogate of the cerebral autoregulation impairment. Fluctuations in ABP, CBFV, and phase shift between them were tested for stationarity using sphericity based test. The Zhao-Atlas-Marks distribution was utilized to estimate the time-frequency coherence (TFCoh and phase shift (TFPS between ABP and CBFV in three frequency ranges: 0.02-0.07 Hz (VLF, 0.07-0.20 Hz (LF, and 0.20-0.35 Hz (HF. TFPS was estimated in regions locally validated by statistically justified value of TFCoh. The comparison of TFPS with spectral phase shift determined using transfer function approach was performed.The hypothesis of stationarity for ABP and CBFV fluctuations and the phase shift was rejected. Reduced TFPS was associated with hypercapnia in the VLF and the LF but not in the HF. Spectral phase shift was also decreased during hypercapnia in the VLF and the LF but increased in the HF. Time-frequency method led to lower dispersion of phase estimates than the spectral method, mainly during normocapnia in the VLF and the LF.The time-frequency method performed no worse than the classic one and yet may offer benefits from lower dispersion of phase shift as well as a more in-depth insight into the dynamic nature of cerebral autoregulation.

  9. Decreased circulation time offsets increased efficacy of PEGylated nanocarriers targeting folate receptors of glioma

    International Nuclear Information System (INIS)

    McNeeley, Kathleen M; Annapragada, Ananth; Bellamkonda, Ravi V

    2007-01-01

    Liposomal and other nanocarrier based drug delivery vehicles can localize to tumours through passive and/or active targeting. Passively targeted liposomal nanocarriers accumulate in tumours via 'leaky' vasculature through the enhanced permeability and retention (EPR) effect. Passive accumulation depends upon the circulation time and the degree of tumour vessel 'leakiness'. After extravasation, actively targeted liposomal nanocarriers efficiently deliver their payload by receptor-mediated uptake. However, incorporation of targeting moieties can compromise circulation time in the blood due to recognition and clearance by the reticuloendothelial system, decreasing passive accumulation. Here, we compare the efficacy of passively targeted doxorubicin-loaded PEGylated liposomal nanocarriers to that of actively targeted liposomal nanocarriers in a rat 9L brain tumour model. Although folate receptor (FR)-targeted liposomal nanocarriers had significantly reduced blood circulation time compared to PEGylated liposomal nanocarriers; intratumoural drug concentrations both at 20 and 50 h after administration were equal for both treatments. Both treatments significantly increased tumour inoculated animal survival by 60-80% compared to non-treated controls, but no difference in survival was observed between FR-targeted and passively targeted nanocarriers. Therefore, alternate approaches allowing for active targeting without compromising circulation time may be important for fully realizing the benefits of receptor-mediated active targeting of gliomas

  10. Intraventricular hemorrhage in the preterm neonate: timing and cerebral blood flow changes

    International Nuclear Information System (INIS)

    Ment, L.R.; Duncan, C.C.; Ehrenkranz, R.A.; Lange, R.C.; Taylor, K.J.; Kleinman, C.S.; Scott, D.T.; Sivo, J.; Gettner, P.

    1984-01-01

    Serial cranial ultrasound studies, 133xenon inhalation cerebral blood flow determinations, and risk factor analyses were performed in 31 preterm neonates. Contrast echocardiographic studies were additionally performed in 16 of these 31 infants. Sixty-one percent were found to have germinal matrix or intraventricular hemorrhage. Seventy-four percent of all hemorrhages were detected by the thirtieth postnatal hour. The patients were divided into three groups: early GMH/IVH by the sixth postnatal hour (eight infants) interval GMH/IVH from 6 hours through 5 days (10), and no GMH/IVH (12). Cerebral blood flow values at 6 postnatal hours were significantly lower for the early GMH/IVH group than for the no GMH/IVH group (P less than 0.01). Progression of GMH/IVH was observed only in those infants with early hemorrhage, and these infants had a significantly higher incidence of neonatal mortality. Ventriculomegaly as determined by ultrasound studies was noted equally in infants with and without GMH/IVH (50%) and was not found to correlate with low cerebral blood flow. The patients with early hemorrhage were distinguishable by their need for more vigorous resuscitation at the time of birth and significantly higher ventilator settings during the first 36 postnatal hours, during which time they also had higher values of PCO2. An equal incidence of patent ductus arteriosus was found across all of the groups. We propose that early GMH/IVH may be related to perinatal events and that the significant decrease in cerebral blood flow found in infants with early GMH/IVH is secondary to the presence of the hemorrhage itself. Progression of early GMH/IVH and new interval GMH/IVH may be related to later neonatal events known to alter cerebral blood flow

  11. Experimental microangiography for measuring cerebral blood circulation following local cold stroke. Experimentelle Mikroangiographie der zerebralen Durchblutung nach lokalem Kaeltetrauma

    Energy Technology Data Exchange (ETDEWEB)

    Ruttmann, G

    1982-01-01

    In 54 female Wistar rats the exposed brain was right-parietally traumatised; cerebral perfusion of two anatomically different brain sections was angiographically imaged and densitometrically evaluated at various instants. The observation period ranged between 1 and 168 hours after the local cold stroke had been applied. Whereas in the telencephal section situated beyond the direct zone of lesion a maximum perfusion difference between the two hemispheres occurred already 1 hour after the animal had been traumatised, a maximum of perfusion difference was observed 6 hours after traumatisation in the diencephalic section situated directly across the site of the cold lesion. Within the first posttraumatic hours the total cerebral perfusion rapidly decreased. The minimum was reached 24 hours after traumatisation. Then it increased again and on the 7th posttraumatic day the perfusion level reached that of the control group. The tendencies of perfusion behaviour differing from one another, which were observed in both hemispheres, followed the course of the total perfusion. The decrease of perfusion occurring during the first hours after traumatisation is provoked by the compressive effect due to the expanding edema. This is principally indicated by the acute hyperperfusion during the first hours to be observed in the telencephalic section. The different velocities at which the hemispheres recover in the diencephalic section must be attributed to metabolic and hypoxic components. The incomplete recovery of perfusion in the injured hemisphere after 7 days may be due to the glial reaction.

  12. Non-linear time series analysis on flow instability of natural circulation under rolling motion condition

    International Nuclear Information System (INIS)

    Zhang, Wenchao; Tan, Sichao; Gao, Puzhen; Wang, Zhanwei; Zhang, Liansheng; Zhang, Hong

    2014-01-01

    Highlights: • Natural circulation flow instabilities in rolling motion are studied. • The method of non-linear time series analysis is used. • Non-linear evolution characteristic of flow instability is analyzed. • Irregular complex flow oscillations are chaotic oscillations. • The effect of rolling parameter on the threshold of chaotic oscillation is studied. - Abstract: Non-linear characteristics of natural circulation flow instabilities under rolling motion conditions were studied by the method of non-linear time series analysis. Experimental flow time series of different dimensionless power and rolling parameters were analyzed based on phase space reconstruction theory. Attractors which were reconstructed in phase space and the geometric invariants, including correlation dimension, Kolmogorov entropy and largest Lyapunov exponent, were determined. Non-linear characteristics of natural circulation flow instabilities under rolling motion conditions was studied based on the results of the geometric invariant analysis. The results indicated that the values of the geometric invariants first increase and then decrease as dimensionless power increases which indicated the non-linear characteristics of the system first enhance and then weaken. The irregular complex flow oscillation is typical chaotic oscillation because the value of geometric invariants is at maximum. The threshold of chaotic oscillation becomes larger as the rolling frequency or rolling amplitude becomes big. The main influencing factors that influence the non-linear characteristics of the natural circulation system under rolling motion are thermal driving force, flow resistance and the additional forces caused by rolling motion. The non-linear characteristics of the natural circulation system under rolling motion changes caused by the change of the feedback and coupling degree among these influencing factors when the dimensionless power or rolling parameters changes

  13. Evaluation of optimal scan duration and end time in cerebral CT perfusion study

    International Nuclear Information System (INIS)

    Hirata, Masaaki; Sugawara, Yoshifumi; Miki, Hitoshi; Mochizuki, Teruhito; Murase, Kenya

    2005-01-01

    The purpose of this study was to evaluate the optimal end time of scanning and the influence of varying the number of source images adopted for calculation of the parameter values in computerized tomography (CT) perfusion. Nineteen CT perfusion studies in 14 patients with cerebrovascular disease were retrospectively analyzed. CT perfusion scanning was performed using continuous scans of 1 sec/rotation x 60 sec with 5-mm-thick sections. To determine the appropriate end time of scanning, the time-density curves (TDCs) of the anterior cerebral artery (ACA), superior sagittal sinus (SSS), and basal ganglia were analyzed. The functional maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were retrospectively generated from various numbers (30, 35, 40, 45, 50, 55, and 60) of source images. Defining the values calculated from the number of source images equal to the end time of the first pass as standard values, the percentage difference between the standard values and the values generated from various numbers of sources were evaluated. The TDCs of SSS showed the latest end time of the first pass (mean, 38.6±5.2 sec; range, 32 to 48 sec). Therefore, the values calculated from the number of source images equal to the end time of the first pass of SSS were defined as standard values. Increase and decrease of the number of source images for calculation resulted in increase of the percentage difference in every parameter value. The percentage differences ranged up to 49.6% for CBF, 48.0% for CBV, and 20.0% for MTT. Scanning until the end time of the first pass of SSS is necessary and sufficient for reliable measurement. Variable scan time based on the TDC of the SSS may be of better utility than use of fixed scan time. Further, the radiation dose could be minimized in many cases by reducing the scan time. (author)

  14. Impact of timing of cranioplasty on hydrocephalus after decompressive hemicraniectomy in malignant middle cerebral artery infarction.

    Science.gov (United States)

    Finger, Tobias; Prinz, Vincent; Schreck, Evelyn; Pinczolits, Alexandra; Bayerl, Simon; Liman, Thomas; Woitzik, Johannes; Vajkoczy, Peter

    2017-02-01

    Patients with malignant middle cerebral artery infarction frequently develop hydrocephalus after decompressive hemicraniectomy. Hydrocephalus itself and known shunt related complications after ventriculo-peritoneal shunt implantation may negatively impact patientś outcome. Here, we aimed to identify factors associated with the development of hydrocephalus after decompressive hemicraniectomy in malignant middle cerebral artery infarction. A total of 99 consecutive patients with the diagnosis of large hemispheric infarctions and the indication for decompressive hemicraniectomy were included. We retrospectively evaluated patient characteristics (gender, age and selected preoperative risk factors), stroke characteristics (side, stroke volume and existing mass effect) and surgical characteristics (size of the bone flap, initial complication rate, time to cranioplasty, complication rate following cranioplasty, type of implant, number of revision surgeries and mortality). Frequency of hydrocephalus development was 10% in our cohort. Patients who developed a hydrocephalus had an earlier time point of bone flap reimplantation compared to the control group (no hydrocephalus=164±104days, hydrocephalus=108±52days, phydrocephalus with a trend towards significance (p=0.08). Communicating hydrocephalus is frequent in patients with malignant middle cerebral artery infarction after decompressive hemicraniectomy. A later time point of cranioplasty might lead to a lower incidence of required shunting procedures in general as we could show in our patient cohort. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Tracking time-varying cerebral autoregulation in response to changes in respiratory PaCO2

    International Nuclear Information System (INIS)

    Liu, Jia; Simpson, M David; Allen, Robert; Yan, Jingyu

    2010-01-01

    Cerebral autoregulation has been studied by linear filter systems, with arterial blood pressure (ABP) as the input and cerebral blood flow velocity (CBFV—from transcranial Doppler Ultrasound) as the output. The current work extends this by using adaptive filters to investigate the dynamics of time-varying cerebral autoregulation during step-wise changes in arterial PaCO 2 . Cerebral autoregulation was transiently impaired in 11 normal adult volunteers, by switching inspiratory air to a CO 2 /air mixture (5% CO 2 , 30% O 2 and 65% N 2 ) for approximately 2 min and then back to the ambient air, causing step-wise changes in end-tidal CO 2 (EtCO 2 ). Simultaneously, ABP and CBFV were recorded continuously. Simulated data corresponding to the same protocol were also generated using an established physiological model, in order to refine the signal analysis methods. Autoregulation was quantified by the time-varying phase lead, estimated from the adaptive filter model. The adaptive filter was able to follow rapid changes in autoregulation, as was confirmed in the simulated data. In the recorded signals, there was a slow decrease in autoregulatory function following the step-wise increase in PaCO 2 (but this did not reach a steady state within approximately 2 min of recording), with a more rapid change in autoregulation on return to normocapnia. Adaptive filter modelling was thus able to demonstrate time-varying autoregulation. It was further noted that impairment and recovery of autoregulation during transient increases in EtCO 2 occur in an asymmetric manner, which should be taken into account when designing experimental protocols for the study of autoregulation

  16. Transit time dispersion in pulmonary and systemic circulation: effects of cardiac output and solute diffusivity.

    Science.gov (United States)

    Weiss, Michael; Krejcie, Tom C; Avram, Michael J

    2006-08-01

    We present an in vivo method for analyzing the distribution kinetics of physiological markers into their respective distribution volumes utilizing information provided by the relative dispersion of transit times. Arterial concentration-time curves of markers of the vascular space [indocyanine green (ICG)], extracellular fluid (inulin), and total body water (antipyrine) measured in awake dogs under control conditions and during phenylephrine or isoproterenol infusion were analyzed by a recirculatory model to estimate the relative dispersions of transit times across the systemic and pulmonary circulation. The transit time dispersion in the systemic circulation was used to calculate the whole body distribution clearance, and an interpretation is given in terms of a lumped organ model of blood-tissue exchange. As predicted by theory, this relative dispersion increased linearly with cardiac output, with a slope that was inversely related to solute diffusivity. The relative dispersion of the flow-limited indicator antipyrine exceeded that of ICG (as a measure of intravascular mixing) only slightly and was consistent with a diffusional equilibration time in the extravascular space of approximately 10 min, except during phenylephrine infusion, which led to an anomalously high relative dispersion. A change in cardiac output did not alter the heterogeneity of capillary transit times of ICG. The results support the view that the relative dispersions of transit times in the systemic and pulmonary circulation estimated from solute disposition data in vivo are useful measures of whole body distribution kinetics of indicators and endogenous substances. This is the first model that explains the effect of flow and capillary permeability on whole body distribution of solutes without assuming well-mixed compartments.

  17. Investigations of the regulation of cerebral circulation by means of functional changes observed on unanaesthetized rabbits during hypoxia, paradoxical sleep and after whole-body γ-exposure (850-150 rad dose range)

    International Nuclear Information System (INIS)

    Dufour, Raymond.

    1977-01-01

    Both the general effects and the effects on cerebral circulation of whole-body exposure were studied at doses of 850, 650, 450, 250 and 150 rads. Early functional changes following exposure demonstrated two juxtaposed mechanisms, a central one and a peripheral one. The central process, slightly sensitive to the dose-effect, occurred earlier and should be at the origin of hyperthermia, hyperventilation, tachycardia, skin vasoconstruction and a slight increase of arterial pressure. The peripheral mechanisms, occurring slightly later should be more sensitive to the dose-effect and might be at the origin of hypothermic effects and cardiovascular depression. The increase of cerebral blood flow occurring at the 450 rad dose should be best explained by the presence of vasotropic substances. A twofold component of cerebral vasotonicity should be assumed that would depend on the autonomous nervous system and myogenous autoregulation [fr

  18. Time-Frequency Characterization of Cerebral Hemodynamics of Migraine Sufferers as Assessed by NIRS Signals

    Directory of Open Access Journals (Sweden)

    Filippo Molinari

    2010-01-01

    Full Text Available Near-infrared spectroscopy (NIRS is a noninvasive system for the real-time monitoring of the concentration of oxygenated (O2Hb and reduced (HHb hemoglobin in the brain cortex. O2Hb and HHb concentrations vary in response to cerebral autoregulation. Sixty-eight women (14 migraineurs without aura, 49 migraineurs with aura, and 5 controls performed breath-holding and hyperventilation during NIRS recordings. Signals were processed using the Choi-Williams time-frequency transform in order to measure the power variation of the very-low frequencies (VLF: 20–40 mHz and of the low frequencies (LF: 40–140 mHz. Results showed that migraineurs without aura present different LF and VLF power levels than controls and migraineurs with aura. The accurate power measurement of the time-frequency analysis allowed for the discrimination of the subjects' hemodynamic patterns. The time-frequency analysis of NIRS signals can be used in clinical practice to assess cerebral hemodynamics.

  19. Time-Frequency Characterization of Cerebral Hemodynamics of Migraine Sufferers as Assessed by NIRS Signals

    Directory of Open Access Journals (Sweden)

    Liboni William

    2010-01-01

    Full Text Available Abstract Near-infrared spectroscopy (NIRS is a noninvasive system for the real-time monitoring of the concentration of oxygenated ( and reduced (HHb hemoglobin in the brain cortex. and HHb concentrations vary in response to cerebral autoregulation. Sixty-eight women (14 migraineurs without aura, 49 migraineurs with aura, and 5 controls performed breath-holding and hyperventilation during NIRS recordings. Signals were processed using the Choi-Williams time-frequency transform in order to measure the power variation of the very-low frequencies (VLF: 20–40 mHz and of the low frequencies (LF: 40–140 mHz. Results showed that migraineurs without aura present different LF and VLF power levels than controls and migraineurs with aura. The accurate power measurement of the time-frequency analysis allowed for the discrimination of the subjects' hemodynamic patterns. The time-frequency analysis of NIRS signals can be used in clinical practice to assess cerebral hemodynamics.

  20. Identification of circulating miRNA biomarkers based on global quantitative real-time PCR profiling

    Directory of Open Access Journals (Sweden)

    Kang Kang

    2012-02-01

    Full Text Available Abstract MicroRNAs (miRNAs are small noncoding RNAs (18-25 nucleotides that regulate gene expression at the post-transcriptional level. Recent studies have demonstrated the presence of miRNAs in the blood circulation. Deregulation of miRNAs in serum or plasma has been associated with many diseases including cancers and cardiovascular diseases, suggesting the possible use of miRNAs as diagnostic biomarkers. However, the detection of the small amount of miRNAs found in serum or plasma requires a method with high sensitivity and accuracy. Therefore, the current study describes polymerase chain reaction (PCR-based methods for measuring circulating miRNAs. Briefly, the procedure involves four major steps: (1 sample collection and preparation; (2 global miRNAs profiling using quantitative real-time PCR (qRT-PCR; (3 data normalization and analysis; and (4 selection and validation of miRNA biomarkers. In conclusion, qRT-PCR is a promising method for profiling of circulating miRNAs as biomarkers.

  1. Prediction about chaotic times series of natural circulation flow under rolling motion

    International Nuclear Information System (INIS)

    Yuan Can; Cai Qi; Guo Li; Yan Feng

    2014-01-01

    The paper have proposed a chaotic time series prediction model, which combined phase space reconstruction with support vector machines. The model has been used to predict the coolant volume flow, in which a synchronous parameter optimization method was brought up based on particle swarm optimization algorithm, since the numerical value selection of related parameter was a key factor for the prediction precision. The average relative error of prediction values and actual observation values was l,5% and relative precision was 0.9879. The result indicated that the model could apply for the natural circulation coolant volume flow prediction under rolling motion condition with high accuracy and robustness. (authors)

  2. Time-resolved near-infrared technique for bedside monitoring of absolute cerebral blood flow

    Science.gov (United States)

    Diop, Mamadou; Tichauer, Kenneth M.; Elliott, Jonathan T.; Migueis, Mark; Lee, Ting-Yim; St. Lawrence, Keith

    2010-02-01

    A primary focus of neurointensive care is monitoring the injured brain to detect harmful events that can impair cerebral blood flow (CBF). Since current non-invasive bedside methods can only indirectly assess blood flow, the goal of this research was to develop an optical technique for measuring absolute CBF. A time-resolved near-infrared (NIR) apparatus was built and its ability to accurately measure changes in optical properties was demonstrated in tissue-mimicking phantoms. The time-resolved system was combined with a bolus-tracking method for measuring CBF using the dye indocyanine green (ICG) as an intravascular flow tracer. Cerebral blood flow was measured in newborn piglets and for comparison, CBF was concurrently measured using a previously developed continuous-wave NIR method. Measurements were acquired with both techniques under three conditions: normocapnia, hypercapnia and following occlusion of the carotid arteries. Mean CBF values (N = 3) acquired with the TR-NIR system were 31.9 +/- 11.7 ml/100g/min during occlusion, 39.7 +/- 1.6 ml/100g/min at normocapnia, and 58.8 +/- 9.9 ml/100g/min at hypercapnia. Results demonstrate that the developed TR-NIR technique has the sensitivity to measure changes in CBF; however, the CBF measurements were approximately 25% lower than the values obtained with the CW-NIRS technique.

  3. Time-related sex differences in cerebral hypoperfusion-induced brain injury

    Directory of Open Access Journals (Sweden)

    Stanojlović Miloš

    2014-01-01

    Full Text Available Although the model of cerebral hypoperfusion in rats has been a matter of many investigations over the years, the exact intracellular and biochemical mechanisms that lead to neuron loss and memory decline have not been clearly identified. In the current study, we examined whether cerebral hypoperfusion causes changes in hippocampal protein expression of apoptotic markers in the synaptosomal fraction and neurodegeneration in a time-dependent and sex-specific manner. Adult male and female Wistar rats were divided into two main groups, controls that underwent sham operation, and animals subjected to permanent bilateral occlusion of common carotid arteries. Both male and female rats were killed 3, 7 or 90 days following the insult. The obtained results indicate that the peak of processes that lead to apoptosis occured on postoperative day 7 and that they were more prominent in males, indicating that neuroprotective effects of certain substances (planned for future experiments, should be tested at this time point. [Projekat Ministarstva nauke Republike Srbije, br. 173044 i br. 41014

  4. The time of appearance and disappearance of fetal DNA from the maternal circulation.

    Science.gov (United States)

    Thomas, M R; Tutschek, B; Frost, A; Rodeck, C H; Yazdani, N; Craft, I; Williamson, R

    1995-07-01

    A single copy Y-chromosome DNA sequence was amplified using the polymerase chain reaction (PCR) from the peripheral blood of 30 women who had achieved a pregnancy through an in vitro fertilization (IVF) programme. The time of conception was known precisely and was confirmed by serial ultrasound scans. Conceptions were dated as the number of weeks after fertilization plus 2, to give a time equivalent to the obstetric menstrual dating of the pregnancy (LMP). Y-chromosome-specific DNA was detected in all pregnancies with a male fetus (18/30). The earliest detection was at 4 weeks and 5 days, and the latest at 7 weeks and 1 day. Y-chromosome-specific sequences were no longer detected in any of the male pregnancies 8 weeks after delivery. No Y-chromosome sequences were detected in any of the pregnancies where only female babies were delivered. This demonstrates that fetal DNA appears in the maternal circulation early in the first trimester, that it can be identified in all pregnancies tested by 7 weeks, that it continues to be present throughout pregnancy, and that it has been cleared from the maternal circulation 2 months after parturition. Early non-invasive prenatal diagnosis for aneuploidies and inherited disorders will be possible in all pregnancies if fetal cells can be isolated free from maternal contamination (or identified accurately in the presence of maternal cells) without problems of contamination from previous pregnancies.

  5. Cerebral blood flow measurement using stable xenon CT with very short inhalation times

    Energy Technology Data Exchange (ETDEWEB)

    Touho, Hajime; Karasawa, Jun; Shishido, Hisashi; Yamada, Keisuke; Shibamoto, Keiji [Osaka Neurological Inst., Toyonaka (Japan)

    1991-02-01

    A noninvasive, simplified method using inhalation of stable xenon (Xe{sup s}) and computed tomographic (CT) scanning to estimate regional cerebral blood flow (rCBF) and regional partition coefficient (r{lambda}) is described. Twenty-four patients with cerebrovascular occlusive disease and six volunteer controls inhaled 30% Xe{sup s} and 70% oxygen for 180 seconds and exhaled for 144 seconds during serial CT scanning without denitrogenation. The end-tidal Xe{sup s} concentration was continuously monitored with a thermoconductivity analyzer to determine the build-up range (A value) and build-up rate constant (K value) for arteries with the curve fitting method. The time-CT number (Hounsfield unit) curve for cerebral tissue during the Xe{sup s} washin and washout phases was used to calculate r{lambda} and rCBF using least squares curve fitting analysis. The resultant r{lambda} and rCBF map demonstrated a reliable distribution between the gray and white matter, and infarcted areas. rCBF was high in gray matter, low in white matter, and much lower in infarcted areas than in white matter. r{lambda} was high in white matter, low in gray matter, and much lower in infarcted areas. Xe{sup s} CT-CBF studies with very short inhalation of 180 seconds is a clinically useful method for evaluation of rCBF in patients with cerebrovascular diseases. (author).

  6. Virtual reality cerebral aneurysm clipping simulation with real-time haptic feedback.

    Science.gov (United States)

    Alaraj, Ali; Luciano, Cristian J; Bailey, Daniel P; Elsenousi, Abdussalam; Roitberg, Ben Z; Bernardo, Antonio; Banerjee, P Pat; Charbel, Fady T

    2015-03-01

    With the decrease in the number of cerebral aneurysms treated surgically and the increase of complexity of those treated surgically, there is a need for simulation-based tools to teach future neurosurgeons the operative techniques of aneurysm clipping. To develop and evaluate the usefulness of a new haptic-based virtual reality simulator in the training of neurosurgical residents. A real-time sensory haptic feedback virtual reality aneurysm clipping simulator was developed using the ImmersiveTouch platform. A prototype middle cerebral artery aneurysm simulation was created from a computed tomographic angiogram. Aneurysm and vessel volume deformation and haptic feedback are provided in a 3-dimensional immersive virtual reality environment. Intraoperative aneurysm rupture was also simulated. Seventeen neurosurgery residents from 3 residency programs tested the simulator and provided feedback on its usefulness and resemblance to real aneurysm clipping surgery. Residents thought that the simulation would be useful in preparing for real-life surgery. About two-thirds of the residents thought that the 3-dimensional immersive anatomic details provided a close resemblance to real operative anatomy and accurate guidance for deciding surgical approaches. They thought the simulation was useful for preoperative surgical rehearsal and neurosurgical training. A third of the residents thought that the technology in its current form provided realistic haptic feedback for aneurysm surgery. Neurosurgical residents thought that the novel immersive VR simulator is helpful in their training, especially because they do not get a chance to perform aneurysm clippings until late in their residency programs.

  7. Phenotypic and Functional Alterations in Circulating Memory CD8 T Cells with Time after Primary Infection.

    Directory of Open Access Journals (Sweden)

    Matthew D Martin

    2015-10-01

    Full Text Available Memory CD8 T cells confer increased protection to immune hosts upon secondary viral, bacterial, and parasitic infections. The level of protection provided depends on the numbers, quality (functional ability, and location of memory CD8 T cells present at the time of infection. While primary memory CD8 T cells can be maintained for the life of the host, the full extent of phenotypic and functional changes that occur over time after initial antigen encounter remains poorly characterized. Here we show that critical properties of circulating primary memory CD8 T cells, including location, phenotype, cytokine production, maintenance, secondary proliferation, secondary memory generation potential, and mitochondrial function change with time after infection. Interestingly, phenotypic and functional alterations in the memory population are not due solely to shifts in the ratio of effector (CD62Llo and central memory (CD62Lhi cells, but also occur within defined CD62Lhi memory CD8 T cell subsets. CD62Lhi memory cells retain the ability to efficiently produce cytokines with time after infection. However, while it is was not formally tested whether changes in CD62Lhi memory CD8 T cells over time occur in a cell intrinsic manner or are due to selective death and/or survival, the gene expression profiles of CD62Lhi memory CD8 T cells change, phenotypic heterogeneity decreases, and mitochondrial function and proliferative capacity in either a lymphopenic environment or in response to antigen re-encounter increase with time. Importantly, and in accordance with their enhanced proliferative and metabolic capabilities, protection provided against chronic LCMV clone-13 infection increases over time for both circulating memory CD8 T cell populations and for CD62Lhi memory cells. Taken together, the data in this study reveal that memory CD8 T cells continue to change with time after infection and suggest that the outcome of vaccination strategies designed to elicit

  8. On cerebral celebrity and reality TV: subjectivity in times of brain scans and psychotainment.

    Science.gov (United States)

    De Vos, Jan

    2009-01-01

    The philosopher Daniel Dennett developed a theory of consciousness in which he replaces the so-called Cartesian theater with conceptions such as "fame in the brain" and "cerebral celebrity." The paradox of this is that Dennett unwittingly reintroduces the metaphors of the stage and the screen. The use of this trope is pursued in this essay in order to juxtapose Dennett's theory with reality TV and celebrity culture. This will allow us to sketch out late-modern subjectivity in times of brains scans and "psychotainment." Drawing on Walter Benjamin, Giorgi Agamben, Slavoj Žižek, and others, a plea is made for a materialism of the zero-level of subjectivity.

  9. Usefulness of measurement of circulation time using MgSO4 : correlation with time-density curve using electron beam computed tomography

    International Nuclear Information System (INIS)

    Kim, Byung Ki; Lee, Hui Joong; Lee, Jong Min; Kim, Yong Joo; Kang, Duck Sik

    1999-01-01

    To determine the usefulness of MgSO 4 for measuring the systemic circulation time. Systemic circulation time, defined as elapsed time from the injection of MgSO 4 solution to the point of pharyngeal burning sensation, was measured in 63 volunteers. MgSO 4 was injected into a superficial vein of an upper extremity. Using dynamic electron beam computed tomography at the level of the abdominal aorta and celiac axis, a time-intensity curve was plotted, and for these two locations, maximal enhancement time was compared. For 60 of the 63 subjects, both systemic circulation time and maximal enhancement time were determined. Average systemic circulation time was 17.4 (SD:3.6) secs. and average maximal enhancement times at the level of the abdominal aorta and celiac axis were 17.5 (SD:3.0) secs. and 18.5 (SD:3.2) secs., respectively. Correlation coefficients between systemic circulation time and maximal enhancement time for the abdominal aorta and celiac axis were 0.73 (p 4 injection and maximal enhancement time for the abdominal aorta showed significant correlation. Thus, to determine the appropriate scanning time in contrast-enhanced radiological studies, MgSO 4 can be used instead of a test bolus study

  10. Bidecadal North Atlantic ocean circulation variability controlled by timing of volcanic eruptions.

    Science.gov (United States)

    Swingedouw, Didier; Ortega, Pablo; Mignot, Juliette; Guilyardi, Eric; Masson-Delmotte, Valérie; Butler, Paul G; Khodri, Myriam; Séférian, Roland

    2015-03-30

    While bidecadal climate variability has been evidenced in several North Atlantic paleoclimate records, its drivers remain poorly understood. Here we show that the subset of CMIP5 historical climate simulations that produce such bidecadal variability exhibits a robust synchronization, with a maximum in Atlantic Meridional Overturning Circulation (AMOC) 15 years after the 1963 Agung eruption. The mechanisms at play involve salinity advection from the Arctic and explain the timing of Great Salinity Anomalies observed in the 1970s and the 1990s. Simulations, as well as Greenland and Iceland paleoclimate records, indicate that coherent bidecadal cycles were excited following five Agung-like volcanic eruptions of the last millennium. Climate simulations and a conceptual model reveal that destructive interference caused by the Pinatubo 1991 eruption may have damped the observed decreasing trend of the AMOC in the 2000s. Our results imply a long-lasting climatic impact and predictability following the next Agung-like eruption.

  11. Plutonium isotopes in the atmosphere of Central Europe: Isotopic composition and time evolution vs. circulation factors

    Energy Technology Data Exchange (ETDEWEB)

    Kierepko, Renata, E-mail: Renata.Kierepko@ifj.edu.pl [Institute of Nuclear Physics, Polish Academy of Sciences, Krakow (Poland); Mietelski, Jerzy W. [Institute of Nuclear Physics, Polish Academy of Sciences, Krakow (Poland); Ustrnul, Zbigniew [Jagiellonian University, Krakow (Poland); Institute of Meteorology and Water Management, National Research Institute, Krakow (Poland); Anczkiewicz, Robert [Institute of Geological Sciences, Polish Academy of Sciences, Krakow (Poland); Wershofen, Herbert [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Holgye, Zoltan [National Radiation Protection Institute, Prague (Czech Republic); Kapała, Jacek [Medical University of Bialystok (Poland); Isajenko, Krzysztof [Central Laboratory for Radiological Protection, Warsaw (Poland)

    2016-11-01

    This paper reports evidence of Pu isotopes in the lower part of the troposphere of Central Europe. The data were obtained based on atmospheric aerosol fraction samples collected from four places in three countries (participating in the informal European network known as the Ring of Five (Ro5)) forming a cell with a surface area of about 200,000 km{sup 2}. We compared our original data sets from Krakow (Poland, 1990–2007) and Bialystok (Poland, 1991–2007) with the results from two other locations, Prague (Czech Republic; 1997–2004) and Braunschweig (Germany; 1990–2003) to find time evolution of the Pu isotopes. The levels of the activity concentration for {sup 238}Pu and for {sup (239} {sup +} {sup 240)}Pu were estimated to be a few and some tens of nBq m{sup −} {sup 3}, respectively. However, we also noted some results were much higher (even about 70 times higher) than the average concentration of {sup 238}Pu in the atmosphere. The achieved complex data sets were used to test a new approach to the problem of solving mixing isotopic traces from various sources (here up to three) in one sample. Results of our model, supported by mesoscale atmospheric circulation parameters, suggest that Pu from nuclear weapon accidents or tests and nuclear burnt-up fuel are present in the air. - Highlights: • Evidence of Pu isotopes in the lower part of the troposphere of Central Europe • The effective annual doses associated with Pu inhalation • New approach to the problem of solving mixed Pu origins in one sample (3SM) • Relationship between Pu isotopes activity concentration and circulation factors.

  12. On cerebrae blood circulation from data of radiocirculography in some diseases of central nervous system in children

    International Nuclear Information System (INIS)

    Dolgov, A.G.; Stroganova, L.I.; Chirkin, N.I.

    1980-01-01

    Results of radioisotope investigation of cerebral blood circulation in 202 children with different pathology of central nervous system are presented. Velocity of cerebral blood flow and time of semiaccumulation and semimoving a preparate were investigated by means of sup(113m)In. It is established that radiocirculography shows clearly the changes in the system of cerebral blood supply and in such diseases as vegetovascular distonia and hypertension syndrome, the radiocirculography data pass ahead the clinical picture

  13. Virtual Reality Cerebral Aneurysm Clipping Simulation With Real-time Haptic Feedback

    Science.gov (United States)

    Alaraj, Ali; Luciano, Cristian J.; Bailey, Daniel P.; Elsenousi, Abdussalam; Roitberg, Ben Z.; Bernardo, Antonio; Banerjee, P. Pat; Charbel, Fady T.

    2014-01-01

    Background With the decrease in the number of cerebral aneurysms treated surgically and the increase of complexity of those treated surgically, there is a need for simulation-based tools to teach future neurosurgeons the operative techniques of aneurysm clipping. Objective To develop and evaluate the usefulness of a new haptic-based virtual reality (VR) simulator in the training of neurosurgical residents. Methods A real-time sensory haptic feedback virtual reality aneurysm clipping simulator was developed using the Immersive Touch platform. A prototype middle cerebral artery aneurysm simulation was created from a computed tomography angiogram. Aneurysm and vessel volume deformation and haptic feedback are provided in a 3-D immersive VR environment. Intraoperative aneurysm rupture was also simulated. Seventeen neurosurgery residents from three residency programs tested the simulator and provided feedback on its usefulness and resemblance to real aneurysm clipping surgery. Results Residents felt that the simulation would be useful in preparing for real-life surgery. About two thirds of the residents felt that the 3-D immersive anatomical details provided a very close resemblance to real operative anatomy and accurate guidance for deciding surgical approaches. They believed the simulation is useful for preoperative surgical rehearsal and neurosurgical training. One third of the residents felt that the technology in its current form provided very realistic haptic feedback for aneurysm surgery. Conclusion Neurosurgical residents felt that the novel immersive VR simulator is helpful in their training especially since they do not get a chance to perform aneurysm clippings until very late in their residency programs. PMID:25599200

  14. Virtual Cerebral Aneurysm Clipping with Real-Time Haptic Force Feedback in Neurosurgical Education.

    Science.gov (United States)

    Gmeiner, Matthias; Dirnberger, Johannes; Fenz, Wolfgang; Gollwitzer, Maria; Wurm, Gabriele; Trenkler, Johannes; Gruber, Andreas

    2018-04-01

    Realistic, safe, and efficient modalities for simulation-based training are highly warranted to enhance the quality of surgical education, and they should be incorporated in resident training. The aim of this study was to develop a patient-specific virtual cerebral aneurysm-clipping simulator with haptic force feedback and real-time deformation of the aneurysm and vessels. A prototype simulator was developed from 2012 to 2016. Evaluation of virtual clipping by blood flow simulation was integrated in this software, and the prototype was evaluated by 18 neurosurgeons. In 4 patients with different medial cerebral artery aneurysms, virtual clipping was performed after real-life surgery, and surgical results were compared regarding clip application, surgical trajectory, and blood flow. After head positioning and craniotomy, bimanual virtual aneurysm clipping with an original forceps was performed. Blood flow simulation demonstrated residual aneurysm filling or branch stenosis. The simulator improved anatomic understanding for 89% of neurosurgeons. Simulation of head positioning and craniotomy was considered realistic by 89% and 94% of users, respectively. Most participants agreed that this simulator should be integrated into neurosurgical education (94%). Our illustrative cases demonstrated that virtual aneurysm surgery was possible using the same trajectory as in real-life cases. Both virtual clipping and blood flow simulation were realistic in broad-based but not calcified aneurysms. Virtual clipping of a calcified aneurysm could be performed using the same surgical trajectory, but not the same clip type. We have successfully developed a virtual aneurysm-clipping simulator. Next, we will prospectively evaluate this device for surgical procedure planning and education. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Measurement of circulation time distribution in a shaking vessel; Yodo kakuhan sonai no junkan jikan bunpu no sokutei

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Y; Hiraoka, S; Tada, Y; Ue, T [Nagoya Institute of Technology, Nagoya (Japan); Koh, S [Toyo Engineering Corp., Tokyo (Japan); Lee, Y [Keimyung University, (Korea, Republic of)

    1996-01-20

    The circulation time distribution of a liquid in a horizontally shaking vessel was observed by tracing particle motion with the liquid. The distribution was affected by the operating conditions. The distribution was monotonous and the flow in the vessel was almost rotational flow at large Fr number. The circulation flow rate q{sub c} derived from the mean circulation time was correlated with Nq{sub c} = 22Fr{sup 2.1}Re{sup 0.2}(d/D){sup -2.6}, where Nq{sub c}, Fr and Re were the dimensionless numbers defined as q{sub c}/Nd{sup 3}, N{sup 2}D/g and Nd{sup 2}/{nu}, respectively, and q{sub c} was defined as {pi}D{sup 2}H/4t{sub c}. It was found from the comparison of the mean circulation time with the mixing time that complete mixing was achieved after about 16 circulations. 12 refs., 9 figs., 1 tab.

  16. Real-time eye lens dose monitoring during cerebral angiography procedures

    International Nuclear Information System (INIS)

    Safari, M.J.; Wong, J.H.D.; Kadir, K.A.A.; Ng, K.H.; Thorpe, N.K.; Cutajar, D.L.; Petasecca, M.; Lerch, M.L.F.; Rosenfeld, A.B.

    2016-01-01

    To develop a real-time dose-monitoring system to measure the patient's eye lens dose during neuro-interventional procedures. Radiation dose received at left outer canthus (LOC) and left eyelid (LE) were measured using Metal-Oxide-Semiconductor Field-Effect Transistor dosimeters on 35 patients who underwent diagnostic or cerebral embolization procedures. The radiation dose received at the LOC region was significantly higher than the dose received by the LE. The maximum eye lens dose of 1492 mGy was measured at LOC region for an AVM case, followed by 907 mGy for an aneurysm case and 665 mGy for a diagnostic angiography procedure. Strong correlations (shown as R 2 ) were observed between kerma-area-product and measured eye doses (LOC: 0.78, LE: 0.68). Lateral and frontal air-kerma showed strong correlations with measured dose at LOC (AK L : 0.93, AK F : 0.78) and a weak correlation with measured dose at LE. A moderate correlation was observed between fluoroscopic time and dose measured at LE and LOC regions. The MOSkin dose-monitoring system represents a new tool enabling real-time monitoring of eye lens dose during neuro-interventional procedures. This system can provide interventionalists with information needed to adjust the clinical procedure to control the patient's dose. (orig.)

  17. Real-time eye lens dose monitoring during cerebral angiography procedures

    Energy Technology Data Exchange (ETDEWEB)

    Safari, M.J.; Wong, J.H.D.; Kadir, K.A.A.; Ng, K.H. [University of Malaya, Department of Biomedical Imaging, Faculty of Medicine, Kuala Lumpur (Malaysia); University of Malaya, University of Malaya Research Imaging Centre (UMRIC), Faculty of Medicine, Kuala Lumpur (Malaysia); Thorpe, N.K.; Cutajar, D.L.; Petasecca, M.; Lerch, M.L.F.; Rosenfeld, A.B. [University of Wollongong, Centre for Medical Radiation Physics (CMRP), Wollongong, NSW (Australia)

    2016-01-15

    To develop a real-time dose-monitoring system to measure the patient's eye lens dose during neuro-interventional procedures. Radiation dose received at left outer canthus (LOC) and left eyelid (LE) were measured using Metal-Oxide-Semiconductor Field-Effect Transistor dosimeters on 35 patients who underwent diagnostic or cerebral embolization procedures. The radiation dose received at the LOC region was significantly higher than the dose received by the LE. The maximum eye lens dose of 1492 mGy was measured at LOC region for an AVM case, followed by 907 mGy for an aneurysm case and 665 mGy for a diagnostic angiography procedure. Strong correlations (shown as R{sup 2}) were observed between kerma-area-product and measured eye doses (LOC: 0.78, LE: 0.68). Lateral and frontal air-kerma showed strong correlations with measured dose at LOC (AK{sub L}: 0.93, AK{sub F}: 0.78) and a weak correlation with measured dose at LE. A moderate correlation was observed between fluoroscopic time and dose measured at LE and LOC regions. The MOSkin dose-monitoring system represents a new tool enabling real-time monitoring of eye lens dose during neuro-interventional procedures. This system can provide interventionalists with information needed to adjust the clinical procedure to control the patient's dose. (orig.)

  18. Functional real-time optoacoustic imaging of middle cerebral artery occlusion in mice.

    Directory of Open Access Journals (Sweden)

    Moritz Kneipp

    Full Text Available BACKGROUND AND PURPOSE: Longitudinal functional imaging studies of stroke are key in identifying the disease progression and possible therapeutic interventions. Here we investigate the applicability of real-time functional optoacoustic imaging for monitoring of stroke progression in the whole brain of living animals. MATERIALS AND METHODS: The middle cerebral artery occlusion (MCAO was used to model stroke in mice, which were imaged preoperatively and the occlusion was kept in place for 60 minutes, after which optoacoustic scans were taken at several time points. RESULTS: Post ischemia an asymmetry of deoxygenated hemoglobin in the brain was observed as a region of hypoxia in the hemisphere affected by the ischemic event. Furthermore, we were able to visualize the penumbra in-vivo as a localized hemodynamically-compromised area adjacent to the region of stroke-induced perfusion deficit. CONCLUSION: The intrinsic sensitivity of the new imaging approach to functional blood parameters, in combination with real time operation and high spatial resolution in deep living tissues, may see it become a valuable and unique tool in the development and monitoring of treatments aimed at suspending the spread of an infarct area.

  19. Systematic assessment of blood circulation time of functionalized upconversion nanoparticles in the chick embryo

    Science.gov (United States)

    Nadort, Annemarie; Liang, Liuen; Grebenik, Ekaterina; Guller, Anna; Lu, Yiqing; Qian, Yi; Goldys, Ewa; Zvyagin, Andrei

    2015-12-01

    Nanoparticle-based delivery of drugs and contrast agents holds great promise in cancer research, because of the increased delivery efficiency compared to `free' drugs and dyes. A versatile platform to investigate nanotechnology is the chick embryo chorioallantoic membrane tumour model, due to its availability (easy, cheap) and accessibility (interventions, imaging). In our group, we developed this model using several tumour cell lines (e.g. breast cancer, colon cancer). In addition, we have synthesized in-house silica coated photoluminescent upconversion nanoparticles with several functional groups (COOH, NH2, PEG). In this work we will present the systematic assessment of their in vivo blood circulation times. To this end, we injected chick embryos grown ex ovo with the functionalized UCNPs and obtained a small amount of blood at several time points after injection to create blood smears The UCNP signal from the blood smears was quantified using a modified inverted microscope imaging set-up. The results of this systematic study are valuable to optimize biochemistry protocols and guide nanomedicine advancement in the versatile chick embryo tumour model.

  20. Studying circulation times of liver cancer cells by in vivo flow cytometry

    Energy Technology Data Exchange (ETDEWEB)

    Liu, G; Li, Y; Fan, Z; Guo, J; Tan, X; Wei, X, E-mail: xwei@fudan.edu.cn [Institutes of Biomedical Sciences, Fudan University, 138 Yi Xue Yuan Road, Shanghai, 200032 (China)

    2011-02-01

    Hepatocellular carcinoma (HCC) may metastasize to lung kidney and many other organs. The survival rate is almost zero for metastatic HCC patients. Molecular mechanisms of HCC metastasis need to be understood better and new therapies must be developed. A recently developed 'in vivo flow cytometer' combined with real-time confocal fluorescence imaging are used to assess spreading and the circulation kinetics of liver tumor cells. The in vivo flow cytometer has the capability to detect and quantify continuously the number and flow characteristics of fluorescently labeled cells in vivo in real time without extracting blood sample. We have measured the depletion kinetics of two related human HCC cell lines high-metastatic HCCLM3 cells and low-metastatic HepG2 cells which were from the same origin and obtained by repetitive screenings in mice. >60% HCCLM3 cells are depleted within the first hour. Interestingly the low-metastatic HepG2 cells possess noticeably slower depletion kinetics. In comparison <40% HepG2 cells are depleted within the first hour. The differences in depletion kinetics might provide insights into early metastasis processes.

  1. [Cerebral protection].

    Science.gov (United States)

    Cattaneo, A D

    1993-09-01

    Cerebral protection means prevention of cerebral neuronal damage. Severe brain damage extinguishes the very "human" functions such as speech, consciousness, intellectual capacity, and emotional integrity. Many pathologic conditions may inflict injuries to the brain, therefore the protection and salvage of cerebral neuronal function must be the top priorities in the care of critically ill patients. Brain tissue has unusually high energy requirements, its stores of energy metabolites are small and, as a result, the brain is totally dependent on a continuous supply of substrates and oxygen, via the circulation. In complete global ischemia (cardiac arrest) reperfusion is characterized by an immediate reactive hyperemia followed within 20-30 min by a delayed hypoperfusion state. It has been postulated that the latter contributes to the ultimate neurologic outcome. In focal ischemia (stroke) the primary focus of necrosis is encircled by an area (ischemic penumbra) that is underperfused and contains neurotoxic substances such as free radicals, prostaglandins, calcium, and excitatory neurotransmitters. The variety of therapeutic effort that have addressed the question of protecting the brain reflects their limited success. 1) Barbiturates. After an initial enthusiastic endorsement by many clinicians and years of vigorous controversy, it can now be unequivocally stated that there is no place for barbiturate therapy following resuscitation from cardiac arrest. One presumed explanation for this negative statement is that cerebral metabolic suppression by barbiturates (and other anesthetics) is impossible in the absence of an active EEG. Conversely, in the event of incomplete ischemia EEG activity in usually present (albeit altered) and metabolic suppression and hence possibly protection can be induced with barbiturates. Indeed, most of the animal studies led to a number of recommendations for barbiturate therapy in man for incomplete ischemia. 2) Isoflurane. From a cerebral

  2. WE-FG-206-05: New Arterial Spin Labeling Method for Simultaneous Estimation of Arterial Cerebral Blood Volume, Cerebral Blood Flow and Arterial Transit Time

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, M; Whitlow, C; Jung, Y [Wake Forest School of Medicine, Winston-Salem, NC (United States); Liu, H [UT MD Anderson Cancer Center, Houston, TX (United States)

    2016-06-15

    Purpose: To demonstrate the feasibility of a novel Arterial Spin Labeling (ASL) method for simultaneously measuring cerebral blood flow (CBF), arterial transit time (ATT), and arterial cerebral blood volume (aCBV) without the use of a contrast agent. Methods: A series of multi-TI ASL images were acquired from one healthy subject on a 3T Siemens Skyra, with the following parameters: PCASL labeling with variable TI [300, 400, 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 3500, 4000] ms, labeling bolus 1400 ms when TI allows, otherwise 100 ms less than TI, TR was minimized for each TI, two sinc shaped pre-saturation pulses were applied in the imaging plane immediately before 2D EPI acquisition. 64×64×24 voxels, 5 mm slice thickness, 1 mm gap, full brain coverage, 6 averages per TI, no crusher gradients, 11 ms TE, scan time of 4:56. The perfusion weighted time-series was created for each voxel and fit to a novel model. The model has two components: 1) the traditional model developed by Buxton et al., accounting for CBF and ATT, and 2) a box car function characterizing the width of the labeling bolus, with variable timing and height in proportion to the aCBV. All three parameters were fit using a nonlinear fitting routine that constrained all parameters to be positive. The main purpose of the high-temporal resolution TI sampling for the first second of data acquisition was to precisely estimate the blood volume component for better detection of arrival time and magnitude of signal. Results: Whole brain maps of CBF, ATT, and aCBV were produced, and all three parameters maps are consistent with similar maps described in the literature. Conclusion: Simultaneous mapping of CBF, ATT, and aCBV is feasible with a clinically tractable scan time (under 5 minutes).

  3. Enhanced conjugation stability and blood circulation time of macromolecular gadolinium-DTPA contrast agent

    Energy Technology Data Exchange (ETDEWEB)

    Jenjob, Ratchapol [Department of New Drug Development, School of Medicine, Inha University, 2F A-dong, Jeongseok Bldg., Sinheung-dong 3-ga, Jung-gu, Incheon 400-712 (Korea, Republic of); Kun, Na [Department of Biotechnology, The Catholic University of Korea, 43 Jibong-ro, Wonmi-gu, Bucheon-si, Gyeonggi-do 420-743 (Korea, Republic of); Ghee, Jung Yeon [Utah-Inha DDS and Advanced Therapeutics, B-403 Meet-You-All Tower, SongdoTechnopark, 7–50, Songdo-dong, Yeonsu-gu, Incheon 406-840 (Korea, Republic of); Shen, Zheyu; Wu, Xiaoxia [Division of Functional Materials and Nano-Devices, Ningbo Institute of Materials Technology & Engineering (NIMTE), Chinese Academy of Sciences, 519 Zhuangshi Street, Zhenhai District, Ningbo, Zhejiang 315201 (China); Cho, Steve K., E-mail: scho@gist.ac.kr [Division of Liberal Arts and Science, GIST College, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Lee, Don Haeng [Utah-Inha DDS and Advanced Therapeutics, B-403 Meet-You-All Tower, SongdoTechnopark, 7–50, Songdo-dong, Yeonsu-gu, Incheon 406-840 (Korea, Republic of); Department of Internal Medicine, School of Medicine, Inha University Hospital, Incheon 420-751 (Korea, Republic of); Yang, Su-Geun, E-mail: Sugeun.Yang@Inha.ac.kr [Department of New Drug Development, School of Medicine, Inha University, 2F A-dong, Jeongseok Bldg., Sinheung-dong 3-ga, Jung-gu, Incheon 400-712 (Korea, Republic of)

    2016-04-01

    In this study, we prepared macromolecular MR T1 contrast agent: pullulan-conjugated Gd diethylene triamine pentaacetate (Gd-DTPA-Pullulan) and estimated residual free Gd{sup 3+}, chelation stability in competition with metal ions, plasma and tissue pharmacokinetics, and abdominal MR contrast on rats. Residual free Gd{sup 3+} in Gd-DTPA-Pullulan was measured using colorimetric spectroscopy. The transmetalation of Gd{sup 3+} incubated with Ca{sup 2+} was performed by using a dialysis membrane (MWCO 100–500 Da) and investigated by ICP-OES. The plasma concentration profiles of Gd-DTPA-Pullulan were estimated after intravenous injection at a dose 0.1 mmol/kg of Gd. The coronal-plane abdominal images of normal rats were observed by MR imaging. The content of free Gd{sup 3+}, the toxic residual form, was less than 0.01%. Chelation stability of Gd-DTPA-Pullulan was estimated, and only 0.2% and 0.00045% of Gd{sup 3+} were released from Gd-DTPA-Pullulan after 2 h incubation with Ca{sup 2+} and Fe{sup 2+}, respectively. Gd-DTPA-Pullulan displayed the extended plasma half-life (t{sub 1/2,α} = 0.43 h, t{sub 1/2,β} = 2.32 h), much longer than 0.11 h and 0.79 h of Gd-EOB-DTPA. Abdominal MR imaging showed Gd-DTPA-Pullulan maintained initial MR contrast for 30 min. The extended plasma half-life of Gd-DTPA-Pullulan probably allows the prolonged MR acquisition time in clinic with enhanced MR contrast. - Highlights: • Macromolecule (pullulan) conjugated Gd contrast agent (Gd-DTPA-Pullulan) showed the extended plasma half-life (t{sub 1/2,α} = 0.43 h, t{sub 1/2,β} = 2.32 h) in comparison with Gd-EOB-DTPA • Gd-DTPA-pullulan T1 contrast agent exhibited strong chelation stability against Gd. • The extended blood circulation attributed the enhanced and prolonged MR contrast on abdominal region of rats. • The extended blood circulation may provide prolonged MR acquisition time window in clinics.

  4. Predicting delayed cerebral ischemia after subarachnoid hemorrhage using physiological time series data.

    Science.gov (United States)

    Park, Soojin; Megjhani, Murad; Frey, Hans-Peter; Grave, Edouard; Wiggins, Chris; Terilli, Kalijah L; Roh, David J; Velazquez, Angela; Agarwal, Sachin; Connolly, E Sander; Schmidt, J Michael; Claassen, Jan; Elhadad, Noemie

    2018-03-20

    To develop and validate a prediction model for delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) using a temporal unsupervised feature engineering approach, demonstrating improved precision over standard features. 488 consecutive SAH admissions from 2006 to 2014 to a tertiary care hospital were included. Models were trained on 80%, while 20% were set aside for validation testing. Baseline information and standard grading scales were evaluated: age, sex, Hunt Hess grade, modified Fisher Scale (mFS), and Glasgow Coma Scale (GCS). An unsupervised approach applying random kernels was used to extract features from physiological time series (systolic and diastolic blood pressure, heart rate, respiratory rate, and oxygen saturation). Classifiers (Partial Least Squares, linear and kernel Support Vector Machines) were trained on feature subsets of the derivation dataset. Models were applied to the validation dataset. The performances of the best classifiers on the validation dataset are reported by feature subset. Standard grading scale (mFS): AUC 0.58. Combined demographics and grading scales: AUC 0.60. Random kernel derived physiologic features: AUC 0.74. Combined baseline and physiologic features with redundant feature reduction: AUC 0.77. Current DCI prediction tools rely on admission imaging and are advantageously simple to employ. However, using an agnostic and computationally inexpensive learning approach for high-frequency physiologic time series data, we demonstrated that our models achieve higher classification accuracy.

  5. Impact of time to return of spontaneous circulation on neuroprotective effect of targeted temperature management at 33 or 36 degrees in comatose survivors of out-of hospital cardiac arrest

    DEFF Research Database (Denmark)

    Kjaergaard, Jesper; Nielsen, Niklas; Winther-Jensen, Matilde

    2015-01-01

    AIM: Time to Return of Spontaneous Circulation (ROSC) has a plausible relation to severity of hypoxic injury before and during resuscitation in Out-of-Hospital Cardiac Arrest (OHCA), and has consistently been associated with adverse outcome. The effect of Targeted Temperature Management (TTM) may...... not be similar over the full spectrum of time to ROSC. This study investigated the possible beneficial effect of targeting 33°C over 36°C on the prognostic importance of time to ROSC. METHODS: In predefined sub-study of the TTM-trial (NEJM 2013) we investigated the relationship between time to ROSC, level of TTM...... and mortality and neurological outcome as assessed by the Cerebral Performance Category (CPC) scale and modified Rankin Scale (mRS) after 180 days. RESULTS: Prolonged time to ROSC was significantly associated with increased mortality with a hazard ratio (HR) of 1.02 per minute (95% CI 1.01-1.02). Level of TTM...

  6. Protective effect of tetraethyl pyrazine against focal cerebral ischemia/reperfusion injury in rats: therapeutic time window and its mechanism.

    Science.gov (United States)

    Jia, Jie; Zhang, Xi; Hu, Yong-Shan; Wu, Yi; Wang, Qing-Zhi; Li, Na-Na; Wu, Cai-Qin; Yu, Hui-Xian; Guo, Qing-Chuan

    2009-03-01

    Tetramethyl pyrazine has been considered an effective agent in treating neurons ischemia/reperfusion injury, but the mechanism of its therapeutic effect remains unclear. This study was to explore the therapeutic time window and mechanism of tetramethyl pyrazine on temporary focal cerebral ischemia/reperfusion injury. Middle cerebral artery occlusion was conducted in male Sprague-Dawley rats and 20 mg/kg of tetramethyl pyrazine was intraperitoneally injected at different time points. At 72 h after reperfusion, all animals' neurologic deficit scores were evaluated. Cerebrums were removed and cerebral infarction volume was measured. The expression of thioredoxin and thioredoxin reductase mRNA was determined at 6 and 24 h after reperfusion. Cerebral infarction volume and neurological deficit scores were significantly decreased in the group with tetramethyl pyrazine treatment. The expression of thioredoxin-1/thioredoxin-2 and thioredoxin reductase-1/thioredoxin reductase-2 was significantly decreased in rats with ischemia/reperfusion injury, while it was increased by tetramethyl pyrazine administration. Treatment with tetramethyl pyrazine, within 4 h after reperfusion, protects the brain from ischemic reperfusion injury in rats. The neuroprotective mechanism of tetramethyl pyrazine treatment is, in part, mediated through the upregulation of thioredoxin transcription.

  7. The Long-Term Outcome Comparison of Different Time-Delayed Kallikrein Treatments in a Mouse Cerebral Ischemic Model

    Directory of Open Access Journals (Sweden)

    Yaohui Ni

    2018-01-01

    Full Text Available Delayed administration of kallikrein after cerebral infarction can improve neurological function. However, the appropriate kallkrein treatment time after ischemic stroke has not been illuminated. In this study, we compared the long-term outcome among three kallikrein therapeutic regimens starting at different time points following mouse cerebral ischemia. Furthermore, the protective mechanisms involving neurogenesis, angiogenesis, and AKT-GSK3β-VEGF signaling pathway were analyzed. Human tissue kallikrein was injected through the tail vein daily starting at 8 h, 24 h, or 36 h after right middle cerebral artery occlusion (MCAO until the 28th day. Three therapeutic regimens all protected against neurological dysfunction, but kallikrein treatment starting at 8 h after MCAO had the best efficacy. Additionally, kallikrein treatment at 8 h after MCAO significantly enhanced cell proliferation including neural stem cell and induced differentiation of neural stem cell into mature neuron. Kallikrein treatment starting at 8 h also promoted more angiogenesis than other two treatment regimens, which was associated with AKT-GSK3β-VEGF signaling pathway. Thus, we confirm that three delayed kallikrein treatments provide protection against cerebral infarction and furthermore suggest that kallikrein treatment starting at 8 h had a better effect than that at 24 h and 36 h. These findings provide the experimental data contributing to better clinical application of exogenous kallikrein.

  8. Cerebral circulation and metabolism in the patients with higher brain dysfunction caused by chronic minor traumatic brain injury. A study by the positron emission tomography in twenty subjects with normal MRI findings

    Energy Technology Data Exchange (ETDEWEB)

    Kabasawa, Hidehiro; Ogawa, Tetsuo; Iida, Akihiko; Matsubara, Michitaka [Nagoya City Rehabilitation and Sports Center (Japan)

    2002-06-01

    Many individuals are affected on their higher brain functions, such as intelligence, memory, and attention, even after minor traumatic brain injury (MTBI). Although higher brain dysfunction is based on impairment of the cerebral circulation and metabolism, the precise relationship between them remains unknown. This study was undertaken to investigate the relationship between the cerebral circulation or cerebral metabolism and higher brain dysfunction. Twenty subjects with higher brain dysfunction caused by chronic MTBI were studied. They had no abnormal MRI findings. The full-scale intelligence quotient (FIQ) were quantitatively evaluated by the Wechsler Adult Intelligence Scale-Revised (WAIS-R), and the subjects were classified into the normal group and the impaired group. Concurrent with the evaluation of FIQ, positron emission tomography (PET) was performed by the steady state method with {sup 15}O gases inhalation. Regional cerebral blood flow (rCBF), oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO{sub 2}) were calculated in the bilateral frontal, parietal, temporal, and occipital lobe. First, of all twenty subjects, we investigated rCBF, OEF and CMRO{sub 2} in all regions. Then we compared rCBF, OEF, and CMRO{sub 2} between the normal group and the impaired group based on FIQ score. We also studied the change of FIQ score of 13 subjects 9.3 months after the first evaluation. In addition, we investigated the change of rCBF, OEF and CMRO{sub 2} along with the improvement of FIQ score. Although rCBF and OEF of all subjects were within the normal range in all regions, CMRO{sub 2} of more than half of subjects was under the lower normal limit in all regions except in the right occipital lobe, showing the presence of ''relative luxury perfusion''. Comparison of rCBF, OEF and CMRO{sub 2} between normal group and impaired group revealed that CMRO{sub 2} of the impaired group was significantly lower than that of the

  9. Cerebral circulation and metabolism in the patients with higher brain dysfunction caused by chronic minor traumatic brain injury. A study by the positron emission tomography in twenty subjects with normal MRI findings

    International Nuclear Information System (INIS)

    Kabasawa, Hidehiro; Ogawa, Tetsuo; Iida, Akihiko; Matsubara, Michitaka

    2002-01-01

    Many individuals are affected on their higher brain functions, such as intelligence, memory, and attention, even after minor traumatic brain injury (MTBI). Although higher brain dysfunction is based on impairment of the cerebral circulation and metabolism, the precise relationship between them remains unknown. This study was undertaken to investigate the relationship between the cerebral circulation or cerebral metabolism and higher brain dysfunction. Twenty subjects with higher brain dysfunction caused by chronic MTBI were studied. They had no abnormal MRI findings. The full-scale intelligence quotient (FIQ) were quantitatively evaluated by the Wechsler Adult Intelligence Scale-Revised (WAIS-R), and the subjects were classified into the normal group and the impaired group. Concurrent with the evaluation of FIQ, positron emission tomography (PET) was performed by the steady state method with 15 O gases inhalation. Regional cerebral blood flow (rCBF), oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO 2 ) were calculated in the bilateral frontal, parietal, temporal, and occipital lobe. First, of all twenty subjects, we investigated rCBF, OEF and CMRO 2 in all regions. Then we compared rCBF, OEF, and CMRO 2 between the normal group and the impaired group based on FIQ score. We also studied the change of FIQ score of 13 subjects 9.3 months after the first evaluation. In addition, we investigated the change of rCBF, OEF and CMRO 2 along with the improvement of FIQ score. Although rCBF and OEF of all subjects were within the normal range in all regions, CMRO 2 of more than half of subjects was under the lower normal limit in all regions except in the right occipital lobe, showing the presence of ''relative luxury perfusion''. Comparison of rCBF, OEF and CMRO 2 between normal group and impaired group revealed that CMRO 2 of the impaired group was significantly lower than that of the normal group in the bilateral frontal, temporal, and occipital

  10. Alterations in the Timing of Huperzine A Cerebral Pharmacodynamics in the Acute Traumatic Brain Injury Setting.

    Science.gov (United States)

    Damar, Ugur; Gersner, Roman; Johnstone, Joshua T; Kapur, Kush; Collins, Stephen; Schachter, Steven; Rotenberg, Alexander

    2018-01-15

    Traumatic brain injury (TBI) may affect the pharmacodynamics of centrally acting drugs. Paired-pulse transcranial magnetic stimulation (ppTMS) is a safe and noninvasive measure of cortical gamma-aminobutyric acid (GABA)-mediated cortical inhibition. Huperzine A (HupA) is a naturally occurring acetylcholinesterase inhibitor with newly discovered potent GABA-mediated antiepileptic capacity, which is reliably detected by ppTMS. To test whether TBI alters cerebral HupA pharmacodynamics, we exposed rats to fluid percussion injury (FPI) and tested whether ppTMS metrics of cortical inhibition differ in magnitude and temporal pattern in injured rats. Anesthetized adult rats were exposed to FPI or sham injury. Ninety minutes post-TBI, rats were injected with HupA or saline (0.6 mg/kg, intraperitoneally). TBI resulted in reduced cortical inhibition 90 min after the injury (N = 18) compared to sham (N = 13) controls (p = 0.03). HupA enhanced cortical inhibition after both sham injury (N = 6; p = 0.002) and TBI (N = 6; p = 0.02). The median time to maximum HupA inhibition in sham and TBI groups were 46.4 and 76.5 min, respectively (p = 0.03). This was consistent with a quadratic trend comparison that projects HupA-mediated cortical inhibition to last longer in injured rats (p = 0.007). We show that 1) cortical GABA-mediated inhibition, as measured by ppTMS, decreases acutely post-TBI, 2) HupA restores lost post-TBI GABA-mediated inhibition, and 3) HupA-mediated enhancement of cortical inhibition is delayed post-TBI. The plausible reasons of the latter include 1) low HupA volume of distribution rendering HupA confined in the intravascular compartment, therefore vulnerable to reduced post-TBI cerebral perfusion, and 2) GABAR dysfunction and increased AChE activity post-TBI.

  11. Circulation of the polar thermosphere during geomagnetically quiet and active times as observed by Dynamics Explorer 2

    International Nuclear Information System (INIS)

    McCormac, F.G.; Killeen, T.L.; Thayer, J.P.; Hernandez, G.; Tschan, C.R.; Ponthieu, J.J.; Spencer, N.W.

    1987-01-01

    Neutral wind measurements obtained by instruments on board the Dynamics Explorer 2 (DE 2) spacecraft have been used to study the effects of geomagnetic activity on the circulation of the high-latitude neutral thermosphere for solar maximum conditions during the periods of November 1981 through January 1982 and November 1982 through January 1983. The data have been sorted and ordered according to the two geophysical indices Kp and (auroral electrojet) AE. Simple expressions have been derived which describe (1) the maximum antisunward wind speed in the geomagnetic polar cap, (2) the maximum sunward wind speeds in the dawn and dusk sectors of the auroral oval, and (3) the latitudinal extent of the polar cap antisunward neutral wind as functions of Kp and AE. The results show a positive correlation between the geomagnetic indices and the three characteristic features of the neutral circulation described above. Averaged vector wind fields in geomagnetic coordinates for Kp ≤ 2 and Kp ≥ 4 in both northern and southern hemispheres for the 6 months have been derived from the data. In doing this, a first-order invariance of the neutral wind circulation in geomagnetic coordinates as a function of universal time (UT) was assumed. The results show a two-cell circulation pattern in the northern winter hemisphere for both quiet and active geomagnetic periods. The cell sizes increase with increasing geomagnetic activity. The dusk cell is always dominant. The southern summer hemisphere averages show only the dusk circulation cell for both quiet and active geomagnetic periods. The cell sizes increase with increasing geomagnetic activity. The dusk cell is always dominant. The southern summer hemisphere averages show only the dusk circulation cell for both quiet and active geomagnetic periods. A diminution of this cell occurs for reduced levels of geomagnetic activity

  12. Statistical Analysis of Categorical Time Series of Atmospheric Elementary Circulation Mechanisms - Dzerdzeevski Classification for the Northern Hemisphere.

    Science.gov (United States)

    Brenčič, Mihael

    2016-01-01

    Northern hemisphere elementary circulation mechanisms, defined with the Dzerdzeevski classification and published on a daily basis from 1899-2012, are analysed with statistical methods as continuous categorical time series. Classification consists of 41 elementary circulation mechanisms (ECM), which are assigned to calendar days. Empirical marginal probabilities of each ECM were determined. Seasonality and the periodicity effect were investigated with moving dispersion filters and randomisation procedure on the ECM categories as well as with the time analyses of the ECM mode. The time series were determined as being non-stationary with strong time-dependent trends. During the investigated period, periodicity interchanges with periods when no seasonality is present. In the time series structure, the strongest division is visible at the milestone of 1986, showing that the atmospheric circulation pattern reflected in the ECM has significantly changed. This change is result of the change in the frequency of ECM categories; before 1986, the appearance of ECM was more diverse, and afterwards fewer ECMs appear. The statistical approach applied to the categorical climatic time series opens up new potential insight into climate variability and change studies that have to be performed in the future.

  13. Cerebral Oximetry in Cardiac Surgery

    Directory of Open Access Journals (Sweden)

    A. N. Shepelyuk

    2012-01-01

    Full Text Available Based on the data of numerous current references, the review describes different neuromonitoring methods during cardiac surgery under extracorporeal circulation. It shows that it is important and necessary to make neuromonitoring for the early diagnosis and prevention of neurological complications after cardiac surgery. Particular attention is given to cerebral oximetry; the possibilities and advantages of this technique are described. Correction of cerebral oximetric values is shown to improve survival rates and to reduce the incidence of postoperative complications. Lack of cerebral oximetry monitoring denudes a clinician of important information and possibilities to optimize patient status and to prevent potentially menacing complications, which allows one to conclude that it is necessary to use cerebral oximetry procedures within neu-romonitoring in cardiac surgery. Key words: extracorporeal circulation, cerebral oximetry, neurological dysfunction, cerebral oxygenation.

  14. Timing and topography of cerebral blood flow, aura, and headache during migraine attacks

    DEFF Research Database (Denmark)

    Olesen, J; Friberg, L; Olsen, T S

    1990-01-01

    Ten years of study has resulted in considerable but fragmented knowledge about regional cerebral blood flow in migraine with aura (classic migraine). In the present study, the number of repeatedly studied patients (n = 63) was large enough to determine statistically significant sequences of event...

  15. Deep cerebral microbleeds are negatively associated with HDL-C in elderly first-time ischemic stroke patients.

    Science.gov (United States)

    Igase, Michiya; Kohara, Katsuhiko; Igase, Keiji; Yamashita, Shiro; Fujisawa, Mutsuo; Katagi, Ryosuke; Miki, Tetsuro

    2013-02-15

    Cerebral microbleeds (CMBs) detected on T2*-weighted MRI gradient-echo have been associated with increased risk of cerebral infarction. We evaluated risk factors for these lesions in a cohort of first-time ischemic stroke patients. Presence of CMBs in consecutive first-time ischemic stroke patients was evaluated. The location of CMBs was classified by cerebral region as strictly lobar (lobar CMBs) and deep or infratentorial (deep CMBs). Logistic regression analysis was performed to determine the contribution of lipid profile to the presence of CMBs. One hundred and sixteen patients with a mean age of 70±10years were recruited. CMBs were present in 74 patients. The deep CMBs group had significantly lower HDL-C levels than those without CMBs. In univariable analysis, advanced periventricular hyperintensity grade (PVH>2) and decreased HDL-C were significantly associated with the deep but not the lobar CMB group. On logistic regression analysis, HDL-C (beta=-0.06, p=0.002) and PVH grade >2 (beta=3.40, p=0.005) were independent determinants of deep CMBs. Low HDL-C may be a risk factor of deep CMBs, including advanced PVH status, in elderly patients with acute ischemic stroke. Management of HDL-C levels might be a therapeutic target for the prevention of recurrence of stroke. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Fluidization behavior in a circulating slugging fluidized bed reactor. Part I : residence time and residence time distribution of polyethylene solids

    NARCIS (Netherlands)

    Putten, van I.C.; Sint Annaland, van M.; Weickert, G.

    2007-01-01

    Square nosed slugging fluidization behavior in a circulating fluidized bed riser using a polyethylene powder with a very wide particle size distribution was studied. In square nosed slugging fluidization the extent of mixing of particles of different size depends on the riser diameter, gas velocity,

  17. Fluidization behavior in a circulating slugging fluidized bed reactor. Part I: Residence time and residence time distribution of polyethylene solids

    NARCIS (Netherlands)

    van Putten, I.C.; van Sint Annaland, M.; Weickert, G.

    2007-01-01

    Square nosed slugging fluidization behavior in a circulating fluidized bed riser using a polyethylene powder with a very wide particle size distribution was studied. In square nosed slugging fluidization the extent of mixing of particles of different size depends on the riser diameter, gas velocity,

  18. Study on time-based variation of blood circulation index, pulse wave energy, and RAI of healthy adult men after different eating times

    Directory of Open Access Journals (Sweden)

    Gyeong-Cheol Kim

    2013-12-01

    Conclusions: Different eating times can bring about changes on blood circulation index, E, and RAI. These changes show a certain tendency and coincide with the physiological factors that eating causes a rise of HR, an increase of systolic cardiac pump performance, and a reduction of peripheral vascular resistance.

  19. Therapeutic time window and underlying therapeutic mechanism of breviscapine injection against cerebral ischemia/reperfusion injury in rats.

    Science.gov (United States)

    Guo, Chao; Zhu, Yanrong; Weng, Yan; Wang, Shiquan; Guan, Yue; Wei, Guo; Yin, Ying; Xi, Miaomaio; Wen, Aidong

    2014-01-01

    Breviscapine injection is a Chinese herbal medicine standardized product extracted from Erigeron breviscapus (Vant.) Hand.-Mazz. It has been widely used for treating cardiovascular and cerebrovascular diseases. However, the therapeutic time window and the action mechanism of breviscapine are still unclear. The present study was designed to investigate the therapeutic time window and underlying therapeutic mechanism of breviscapine injection against cerebral ischemic/reperfusion injury. Sprague-Dawley rats were subjected to middle cerebral artery occlusion for 2h followed by 24h of reperfusion. Experiment part 1 was used to investigate the therapeutic time window of breviscapine. Rats were injected intravenously with 50mg/kg breviscapine at different time-points of reperfusion. After 24h of reperfusion, neurologic score, infarct volume, brain water content and serum level of neuron specific enolase (NSE) were measured in a masked fashion. Part 2 was used to explore the therapeutic mechanism of breviscapine. 4-Hydroxy-2-nonenal (4-HNE), 8-hydroxyl-2'- deoxyguanosine (8-OHdG) and the antioxidant capacity of ischemia cortex were measured by ELISA and ferric-reducing antioxidant power (FRAP) assay, respectively. Immunofluorescence and western blot analysis were used to analyze the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). Part 1: breviscapine injection significantly ameliorated neurologic deficit, reduced infarct volume and water content, and suppressed the levels of NSE in a time-dependent manner. Part 2: breviscapine inhibited the increased levels of 4-HNE and 8-OHdG, and enhanced the antioxidant capacity of cortex tissue. Moreover, breviscapine obviously raised the expression of Nrf2 and HO-1 proteins after 24h of reperfusion. The therapeutic time window of breviscapine injection for cerebral ischemia/reperfusion injury seemed to be within 5h after reperfusion. By up-regulating the expression of Nrf2/HO-1 pathway

  20. Diameter measurements of cerebral arteries on three-dimensional time-of-flight MR angiograms

    International Nuclear Information System (INIS)

    Zhang Yuzhong; Zhang Xuelin; Chang Renmin; Cang Peng; Liu Xingyuan; Xia Qiong

    2003-01-01

    Objective: To measure and establish the normal values of diameters of Chinese cerebral arteries on MRA. Methods: The diameters of the cerebral arteries in 100 persons with normal findings on 3D TOF MRA were measured with projector. There were 53 males and 47 females with the mean age of 45.8 years. 12 subjects were younger than 14 years and 88 were older than 14 years. The diameter differences between the left and the right, in gender and in ages were analyzed statistically. Results: The measurements of each arterial diameter were as follows: Ophthalmic artery: (0.8 ±0.2) mm in male, (0.9±0.2) mm in female. C2 segment of internal carotid artery (ICA-C2): (3.0±0.3) mm (≤14 years) and (3.5±0.6) mm (>14 years) in male, (2.8±0.6) mm (≤14 years) and (3.1±0.5) mm (>14 years) in female. ICA-C4: (4.3±0.6) mm in male, (3.9±0.6) mm in female. A1 segment of anterior cerebral artery (ACA-A1): (2.1±0.4) mm in male, (2.1±0.4) mm in female. Anterior communicating artery (ACoA) : (1.4±0.4) mm in male, (1.3±0.4) mm in female. M1 segment of middle cerebral artery (MCA-M1) : (2.7±0.4) mm in male, (2.6±0.4) mm in female. Basilar artery (BA) : (2.9±0.5) mm in male, (2.8±0.4) mm in female. P1 segment of posterior cerebral artery (PCA-P1) : (2.1±0.5) mm on the left and (2.0±0.5) mm on the right in male, (2.0±0.3) mm on the left and (1.9±0.3) mm on the right in female. PCA-P2: (1.8±0.4) mm in male, (1.7±0.3) mm in female. Posterior communicating artery (PCoA): (1.1±0.3) mm in male, (1.2±0.4) mm in female. Among various diameters, only PCA-P1 had significant difference between the left and the right ( P=0.003); only MCA-M1 (P =0.048), PCA-P1 (P=0.012), ICA-C2 (P=0.000) and C4 segments (P=0.000) had significant differences in gender, respectively; and only ICA-C2 had significant difference in age (P=0.001). Of these significantly different diameters, the diameters in male were larger than those in female. There were significant correlation between PCA-P1 and PCA

  1. NOTICONA--a nonlinear time-domain computer code of two-phase natural circulation instability

    International Nuclear Information System (INIS)

    Su Guanghui; Guo Yujun; Zhang Jinling; Qiu Shuizheng; Jia Dounan; Yu Zhenwan

    1997-10-01

    A microcomputer code, NOTICONA, is developed, which is used for non-linear analysing the two-phase natural circulation systems. The mathematical model of the code includes point source neutron-kinetic model, the feedback of reactivity model, single-phase and two-phase flow model, heat transfer model in different conditions, associated model, etc. NOTICONA is compared with experiments, and its correctness and accuracy are proved. Using NOTICONA, the density wave oscillation (type I) of the 5 MW Test Heating Reactor are calculated, and the marginal stability boundary is obtained

  2. Preliminary study of the scan-delay-time during the combined examation of CT perfusion and CT angiography after contrast media administration in cerebral and cervical CT angiography

    International Nuclear Information System (INIS)

    Cai Wu; Gong Jianping; Zhu Jiangtao; Qiao Fang; Chen Guangqiang; Zhang Bo; Yi Bixing; Qian Minghui

    2010-01-01

    Objective: To discuss the feasibility of the time to peak of cerebral CT perfusion (CTP) in predicting the scan-delay-time after contrast media administration in cerebral and cervical CT angiography (CTA). Methods: Retrospective Analysis was performed in eighty patients who had been examined with cerebral and cervical CTA, they were divided randomly into two groups. Group A:40 patients were performed by the method of experience of 20 seconds as scan-delay-time. Group B:the other 40 patients were examined with the combination scanning technology of CTP-CTA. They were all measured with enhancement value of CT in the M1 segment of left middle cerebral artery, superior sagittal sinus , left common carotid artery adjacent to the fourth cervical vertebrace and internal jugular vein, and then calculate the difference between the arterys and the veins in the same layer. Statistical significance was determined with t test. Results: (1)The enhancement value of CT in the cerebral and cervical artery vessels and the resolving power between the arterys and the veins in the same layer of group B were higher than that in group A. (2) Group B whose cerebral and cervical artery vessels rescontructed from the raw CT data set showed clearly; There were an advance in 3 cases (7.5%), a delay in 5 cases (12.5%) in group A whose cerebral and cervical artery vessels rescontructed from the raw CT data set didn't show clearly.Conclusion It's a satisfactory method based on successful cerebral and cervical CTA study to take the time to peak in CT perfusion as the scan-delay-time during the combined examination of CTP and CTA with 64-detector spiral CT. (authors)

  3. Real-time changes in brain tissue oxygen during endovascular treatment of cerebral vasospasm

    DEFF Research Database (Denmark)

    Rasmussen, Rune; Bache, Søren; Stavngaard, Trine

    2015-01-01

    pressure (PtiO₂) in target parenchyma. However, during the intervention, dangerously low levels of brain tissue oxygen, leading to cerebral infarction, may occur. Thus, no clinical improvement was seen in two of the patients and a dramatic worsening was observed in the third patient. Because the decrease...... minute-by-minute changes in brain tissue oxygen during balloon angioplasty and intraarterial administration of vasodilators in three patients.Our results confirm that endovascular intervention is capable of not only resolving angiographic vasospasm, but also of normalizing values of brain tissue oxygen...... in brain tissue oxygen was seen after administration of vasopressor agents, this may be a contributing factor....

  4. Winter atmospheric circulation signature for the timing of the spring bloom of diatoms in the North Sea

    Science.gov (United States)

    Lohmann, Gerrit; Wiltshire, Karen

    2015-04-01

    Analysing long-term diatom data from the German Bight and observational climate data for the period 1962-2005, we found a close connection of the inter-annual variation of the timing of the spring bloom with the boreal winter atmospheric circulation. We examined the fact that high diatom counts of the spring bloom tended to occur later when the atmospheric circulation was characterized by winter blocking over Scandinavia. The associated pattern in the sea level pressure showed a pressure dipole with two centres located over the Azores and Norway and was tilted compared to the North Atlantic Oscillation. The bloom was earlier when the cyclonic circulation over Scandinavia allowed an increased inflow of Atlantic water into the North Sea which is associated with clearer, more marine water, and warmer conditions. The bloom was later when a more continental atmospheric flow from the east was detected. At Helgoland Roads, it seems that under turbid water conditions (= low light) zooplankton grazing can affect the timing of the phytoplankton bloom negatively. Warmer water temperatures will facilitate this. Under clear water conditions, light will be the main governing factor with regard to the timing of the spring bloom. These different water conditions are shown here to be mainly related to large-scale weather patterns. We found that the mean diatom bloom could be predicted from the sea level pressure one to three months in advance. Using historical pressure data, we derived a proxy for the timing of the spring bloom over the last centuries, showing an increased number of late (proxy-) blooms during the eighteenth century when the climate was considerably colder than today. We argue that these variations are important for the interpretation of inter-annual to centennial variations of biological processes. This is of particular interest when considering future scenarios, as well to considerations on past and future effects on the primary production and food webs.

  5. Real time monitoring of pulsatile change in hemoglobin concentrations of cerebral tissue by a portable tissue oximeter with a 10-Hz sampling rate

    Science.gov (United States)

    Shiga, Toshikazu; Chihara, Eiichi; Tanabe, Kazuhisa; Tanaka, Yoshifumi; Yamamoto, Katsuyuki

    1998-01-01

    A portable CW tissue oximeter of a 10-Hz sampling rate was developed for examination of pulsatile components of the output signals as a mean of checking the signal reliability during long-term monitoring. Feasible studies were performed on a healthy subject. Changes in Hb and HbO2 signals of cerebral tissue were continuously measured by placing a photoprobe on the forehead during 6-hour sleep. Pulsatile changes in Hb and HbO2 were steadily observed over a whole period of the recording. The phase relation of pulsation in Hb and HbO2 was almost inverse. Not only information for reliable monitoring but also physiological parameters with respect to cerebral circulation and metabolism could be obtained by measuring the pulsatile components.

  6. Simultaneous quantitative assessment of circulating cell-free mitochondrial and nuclear DNA by multiplex real-time PCR

    Directory of Open Access Journals (Sweden)

    Peng Xia

    2009-01-01

    Full Text Available Quantification of circulating nucleic acids in plasma and serum could be used as a non-invasive diagnostic tool for monitoring a wide variety of diseases and conditions. We describe here a rapid, simple and accurate multiplex real-time PCR method for direct synchronized analysis of circulating cell-free (ccf mitochondrial (mtDNA and nuclear (nDNA DNA in plasma and serum samples. The method is based on one-step multiplex real-time PCR using a FAM-labeled MGB probe and primers to amplify the mtDNA sequence of the ATP 8 gene, and a VIC-labeled MGB probe and primers to amplify the nDNA sequence of the glycerinaldehyde-3-phosphate-dehydrogenase (GAPDH gene, in plasma and serum samples simultaneously. The efficiencies of the multiplex assays were measured in serial dilutions. Based on the simulation of the PCR reaction kinetics, the relative quantities of ccf mtDNA were calculated using a very simple equation. Using our optimised real-time PCR conditions, close to 100% efficiency was obtained from the two assays. The two assays performed in the dilution series showed very good and reproducible correlation to each other. This optimised multiplex real-time PCR protocol can be widely used for synchronized quantification of mtDNA and nDNA in different samples, with a very high rate of efficiency.

  7. Effects of Participation in Sports Programs on Walking Ability and Endurance Over Time in Children With Cerebral Palsy.

    Science.gov (United States)

    Ross, Sandy A; Yount, Morgan; Ankarstad, Sara; Bock, Samantha; Orso, Britta; Perry, Kimberly; Miros, Jennifer; Brunstrom-Hernandez, Janice E

    2017-12-01

    Children with cerebral palsy may benefit from maintaining a high level of physical fitness similar to typically developing children especially in terms of long-term physical performance, although in practice this is often difficult. The purpose of this study was to determine the effect of participation in sports programs on walking ability and endurance over time. A retrospective cohort study included participants with cerebral palsy, aged 6 to 20 yrs, who attended a summer sports program from 2004 to 2012. There were 256 participant sessions with pre/post data recorded. The participants consisted of a total of 97 children (mean age [SD] = 11.4 [3.1] yrs), many of whom attended multiple programs throughout the years. Programs were held 6 hrs/d, 5 d/wk for up to 4 wks. Outcome measures included the Timed Up and Go, modified 6-min walk, and 25-ft walk/run. The results showed significant improvements in the Timed Up and Go, modified 6-min walk distance and 25-ft walk/run over time. Children in Gross Motor Classification System level III made the largest gains. Walking ability and endurance seem to improve after participation in an intensive summer sports programs. Higher frequency of program attendance resulted in significant improvements in the Timed Up and Go. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) Discuss the importance of physical activity at the participation level (sports programs) for children with cerebral palsy; (2) Contrast the changes in walking ability and endurance for children in Gross Motor Function Classification System level I, II, and III after sports programs; and (3) Identify the impact of higher frequency of sports program attendance over time on walking ability. Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to

  8. Clinical usefulness of augmented reality using infrared camera based real-time feedback on gait function in cerebral palsy: a case study.

    Science.gov (United States)

    Lee, Byoung-Hee

    2016-04-01

    [Purpose] This study investigated the effects of real-time feedback using infrared camera recognition technology-based augmented reality in gait training for children with cerebral palsy. [Subjects] Two subjects with cerebral palsy were recruited. [Methods] In this study, augmented reality based real-time feedback training was conducted for the subjects in two 30-minute sessions per week for four weeks. Spatiotemporal gait parameters were used to measure the effect of augmented reality-based real-time feedback training. [Results] Velocity, cadence, bilateral step and stride length, and functional ambulation improved after the intervention in both cases. [Conclusion] Although additional follow-up studies of the augmented reality based real-time feedback training are required, the results of this study demonstrate that it improved the gait ability of two children with cerebral palsy. These findings suggest a variety of applications of conservative therapeutic methods which require future clinical trials.

  9. Low prevalence of collateral cerebral circulation in the circle of Willis in patients with severe carotid artery stenosis and recent ischemic stroke.

    Science.gov (United States)

    Badacz, Rafał; Przewłocki, Tadeusz; Karch, Izabela; Pieniążek, Piotr; Rosławiecka, Agnieszka; Mleczko, Szymon; Brzychczy, Andrzej; Trystuła, Mariusz; Żmudka, Krzysztof; Kabłak-Ziembicka, Anna

    2015-01-01

    The circle of Willis is thought to play a key role in development of collateral flow in patients with internal carotid artery stenosis (ICAS). To assess flow in the circle of Willis in patients with recent ischemic stroke (IS). The study included 371 patients, 102 symptomatic with severe ICAS and recent IS (within the last 3 months) (group I) and 269 asymptomatic with severe ICAS (group II). Flow in the middle (MCA), anterior (ACA) and posterior (PCA) cerebral arteries and pattern of the cross-flow through anterior (ACoA) and posterior (PCoA) communicating arteries were assessed with transcranial color-coded Doppler ultrasonography (TCCD). The ACoA or PCoA was less prevalent in group I than in group II (54% vs. 78%, p PCoA and higher PSV in the MCA and ACA were associated with significant risk reduction of IS (RR = 0.28 (95% CI = 0.16-0.49, p PCoA seem to play a key role in the evaluation of IS risk in subjects with severe ICAS.

  10. Dual-time-point O-(2-[18F]fluoroethyl)-L-tyrosine PET for grading of cerebral gliomas

    International Nuclear Information System (INIS)

    Lohmann, Philipp; Herzog, Hans; Rota Kops, Elena; Stoffels, Gabriele; Judov, Natalie; Filss, Christian; Tellmann, Lutz; Galldiks, Norbert; Weiss, Carolin; Sabel, Michael; Coenen, Heinz Hubert; Shah, Nadim Jon; Langen, Karl-Josef

    2015-01-01

    We aimed to evaluate the diagnostic potential of dual-time-point imaging with positron emission tomography (PET) using O-(2-[ 18 F]fluoroethyl)-L-tyrosine ( 18 F-FET) for non-invasive grading of cerebral gliomas compared with a dynamic approach. Thirty-six patients with histologically confirmed cerebral gliomas (21 primary, 15 recurrent; 24 high-grade, 12 low-grade) underwent dynamic PET from 0 to 50 min post-injection (p.i.) of 18 F-FET, and additionally from 70 to 90 min p.i. Mean tumour-to-brain ratios (TBR mean ) of 18 F-FET uptake were determined in early (20-40 min p.i.) and late (70-90 min p.i.) examinations. Time-activity curves (TAC) of the tumours from 0 to 50 min after injection were assigned to different patterns. The diagnostic accuracy of changes of 18 F-FET uptake between early and late examinations for tumour grading was compared to that of curve pattern analysis from 0 to 50 min p.i. of 18 F-FET. The diagnostic accuracy of changes of the TBR mean of 18 F-FET PET uptake between early and late examinations for the identification of HGG was 81 % (sensitivity 83 %; specificity 75 %; cutoff - 8 %; p < 0.001), and 83 % for curve pattern analysis (sensitivity 88 %; specificity 75 %; p < 0.001). Dual-time-point imaging of 18 F-FET uptake in gliomas achieves diagnostic accuracy for tumour grading that is similar to the more time-consuming dynamic data acquisition protocol. (orig.)

  11. Dual-time-point O-(2-[{sup 18}F]fluoroethyl)-L-tyrosine PET for grading of cerebral gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Lohmann, Philipp; Herzog, Hans; Rota Kops, Elena; Stoffels, Gabriele; Judov, Natalie; Filss, Christian; Tellmann, Lutz [Forschungszentrum Juelich, Institute of Neuroscience and Medicine, Juelich (Germany); Galldiks, Norbert [Forschungszentrum Juelich, Institute of Neuroscience and Medicine, Juelich (Germany); University of Cologne, Department of Neurology, Cologne (Germany); Weiss, Carolin [University of Cologne, Department of Neurosurgery, Cologne (Germany); Sabel, Michael [Heinrich-Heine University, Department of Neurosurgery, Duesseldorf (Germany); Coenen, Heinz Hubert [Forschungszentrum Juelich, Institute of Neuroscience and Medicine, Juelich (Germany); Juelich-Aachen Research Alliance (JARA) - Section JARA-Brain, Juelich (Germany); Shah, Nadim Jon [Forschungszentrum Juelich, Institute of Neuroscience and Medicine, Juelich (Germany); Juelich-Aachen Research Alliance (JARA) - Section JARA-Brain, Juelich (Germany); RWTH Aachen University Hospital, Department of Neurology, Aachen (Germany); Langen, Karl-Josef [Forschungszentrum Juelich, Institute of Neuroscience and Medicine, Juelich (Germany); RWTH Aachen University Hospital, Department of Nuclear Medicine, Aachen (Germany); Juelich-Aachen Research Alliance (JARA) - Section JARA-Brain, Juelich (Germany)

    2015-10-15

    We aimed to evaluate the diagnostic potential of dual-time-point imaging with positron emission tomography (PET) using O-(2-[{sup 18}F]fluoroethyl)-L-tyrosine ({sup 18}F-FET) for non-invasive grading of cerebral gliomas compared with a dynamic approach. Thirty-six patients with histologically confirmed cerebral gliomas (21 primary, 15 recurrent; 24 high-grade, 12 low-grade) underwent dynamic PET from 0 to 50 min post-injection (p.i.) of {sup 18}F-FET, and additionally from 70 to 90 min p.i. Mean tumour-to-brain ratios (TBR{sub mean}) of {sup 18}F-FET uptake were determined in early (20-40 min p.i.) and late (70-90 min p.i.) examinations. Time-activity curves (TAC) of the tumours from 0 to 50 min after injection were assigned to different patterns. The diagnostic accuracy of changes of {sup 18}F-FET uptake between early and late examinations for tumour grading was compared to that of curve pattern analysis from 0 to 50 min p.i. of {sup 18}F-FET. The diagnostic accuracy of changes of the TBR{sub mean} of {sup 18}F-FET PET uptake between early and late examinations for the identification of HGG was 81 % (sensitivity 83 %; specificity 75 %; cutoff - 8 %; p < 0.001), and 83 % for curve pattern analysis (sensitivity 88 %; specificity 75 %; p < 0.001). Dual-time-point imaging of {sup 18}F-FET uptake in gliomas achieves diagnostic accuracy for tumour grading that is similar to the more time-consuming dynamic data acquisition protocol. (orig.)

  12. A pollen-based reconstruction of summer temperature in central North America and implications for circulation patterns during medieval times

    Science.gov (United States)

    Wahl, Eugene R.; Diaz, Henry F.; Ohlwein, Christian

    2012-03-01

    We present a reconstruction of mean summer temperature for the northern Midwest of the USA based on lacustrine pollen records from three different lakes in Wisconsin. The results suggest a relatively warm period during the earlier part of the record (~ 1200-1500 CE) followed by a cooler Little Ice Age (~ 1500-1900) and a subsequent warming to modern conditions. The reconstructed modern summer mean temperature is in good agreement with observations, and the decades of the 1930s to 1950s appear to be the warmest such period in the proxy record (through 1974). Analyses of circulation features associated with the warmest summers in the recent climate record suggest a prevalence of continental ridging accompanied by generally dry conditions during these warm summers in the Midwest. Drought reconstruction using the Palmer Drought Severity Index (PDSI) and tree-ring records as predictors also yield relatively dry conditions in medieval times for the central US. As reported in a number of recent studies, possible forcing mechanisms include La Niña-like conditions in the equatorial Pacific and warmer than average waters in the tropical Indo-western Pacific Ocean possibly coupled to a positive mode of the AMO/NAO North Atlantic circulation pattern.

  13. Detection of the circulating antigen 14-3-3 protein of Schistosoma japonicum by time-resolved fluoroimmunoassay in rabbits

    Directory of Open Access Journals (Sweden)

    Wang Jie

    2011-05-01

    Full Text Available Abstract Background Schistosomiasis remains a major public health concern that afflicts millions of people worldwide. Low levels of Schistosoma infection require more sensitive diagnostic methods. In this study, a time-resolved fluoroimmunoassay (TRFIA was developed for detecting the signal transduction protein 14-3-3, a circulating antigen of Schistosoma japonicum. Results The detection limit of 14-3-3-TRFIA was 0.78 ng/ml, with a linear measurement range from 0.78 to 800 ng/ml. The average intra-assay and inter-assay variability of this TRFIA was 8.9% and 12.2% respectively, and the mean recovery rate ranged from 92.1% to 115.5%. Within the first 21 days post-infection in rabbits, the positive rates of the 14-3-3-TRFIA were distinctly higher compared to ELISA. All these findings illustrate that 14-3-3-TRFIA has a higher detection efficacy and is a good early diagnostic method for active Schistosoma infection. Conclusions A sandwich TRFIA for detecting the circulating antigen 14-3-3 of S. japonicum has been developed, and has demonstrated to be a good potential diagnostic method for schistosomiasis.

  14. Circulation and hydrological characteristics of the North Aegean Sea: a contribution from real-time buoy measurements

    Directory of Open Access Journals (Sweden)

    K. NITTIS

    2002-06-01

    Full Text Available In the framework of the POSEIDON Project, a network of open sea oceanographic buoys equipped with meteorological and oceanographic sensors has been operational in the Aegean Sea since 1998. The analysis of upper-ocean physical data (currents at 3m, temperature and salinity at 3-40m depths collected during the last 2 years from the stations of the North Aegean basin indicates a strong temporal variability of flow field and hydrological characteristics in both synoptic and seasonal time scales. The northern part of the basin is mainly influenced by the Black Sea Water outflow and the mesoscale variability of the corresponding thermohaline fronts, while the southern stations are influenced by the general circulation of the Aegean Sea with strong modulations caused by the seasonally varying atmospheric forcing.

  15. Time-resolved absorption and hemoglobin concentration difference maps: a method to retrieve depth-related information on cerebral hemodynamics.

    Science.gov (United States)

    Montcel, Bruno; Chabrier, Renée; Poulet, Patrick

    2006-12-01

    Time-resolved diffuse optical methods have been applied to detect hemodynamic changes induced by cerebral activity. We describe a near infrared spectroscopic (NIRS) reconstruction free method which allows retrieving depth-related information on absorption variations. Variations in the absorption coefficient of tissues have been computed over the duration of the whole experiment, but also over each temporal step of the time-resolved optical signal, using the microscopic Beer-Lambert law.Finite element simulations show that time-resolved computation of the absorption difference as a function of the propagation time of detected photons is sensitive to the depth profile of optical absorption variations. Differences in deoxyhemoglobin and oxyhemoglobin concentrations can also be calculated from multi-wavelength measurements. Experimental validations of the simulated results have been obtained for resin phantoms. They confirm that time-resolved computation of the absorption differences exhibited completely different behaviours, depending on whether these variations occurred deeply or superficially. The hemodynamic response to a short finger tapping stimulus was measured over the motor cortex and compared to experiments involving Valsalva manoeuvres. Functional maps were also calculated for the hemodynamic response induced by finger tapping movements.

  16. How Robust Are the Surface Temperature Fingerprints of the Atlantic Overturning Meridional Circulation on Monthly Time Scales?

    Science.gov (United States)

    Alexander-Turner, R.; Ortega, P.; Robson, J. I.

    2018-04-01

    It has been suggested that changes in the Atlantic Meridional Overturning Circulation (AMOC) can drive sea surface temperature (SST) on monthly time scales (Duchez et al., 2016, https://doi.org/10.1002/2017GB005667). However, with only 11 years of continuous observations, the validity of this result over longer, or different, time periods is uncertain. In this study, we use a 120 yearlong control simulation from a high-resolution climate model to test the robustness of the AMOC fingerprints. The model reproduces the observed AMOC seasonal cycle and its variability, and the observed 5-month lagged AMOC-SST fingerprints derived from 11 years of data. However, the AMOC-SST fingerprints are very sensitive to the particular time period considered. In particular, both the Florida current and the upper mid-ocean transport produce highly inconsistent fingerprints when using time periods shorter than 30 years. Therefore, several decades of RAPID observations will be necessary to determine the real impact of the AMOC on SSTs at monthly time scales.

  17. Twenty-Four-Hour Real-Time Continuous Monitoring of Cerebral Edema in Rabbits Based on a Noninvasive and Noncontact System of Magnetic Induction

    Directory of Open Access Journals (Sweden)

    Gen Li

    2017-03-01

    Full Text Available Cerebral edema is a common disease, secondary to craniocerebral injury, and real-time continuous monitoring of cerebral edema is crucial for treating patients after traumatic brain injury. This work established a noninvasive and noncontact system by monitoring the magnetic induction phase shift (MIPS which is associated with brain tissue conductivity. Sixteen rabbits (experimental group n = 10, control group, n = 6 were used to perform a 24 h MIPS and intracranial pressure (ICP simultaneously monitored experimental study. For the experimental group, after the establishment of epidural freeze-induced cerebral edema models, the MIPS presented a downward trend within 24 h, with a change magnitude of −13.1121 ± 2.3953°; the ICP presented an upward trend within 24 h, with a change magnitude of 12–41 mmHg. The ICP was negatively correlated with the MIPS. In the control group, the MIPS change amplitude was −0.87795 ± 1.5146 without obvious changes; the ICP fluctuated only slightly at the initial value of 12 mmHg. MIPS had a more sensitive performance than ICP in the early stage of cerebral edema. These results showed that this system is basically capable of monitoring gradual increases in the cerebral edema solution volume. To some extent, the MIPS has the potential to reflect the ICP changes.

  18. Cerebral blood flow: Physiologic and clinical aspects

    International Nuclear Information System (INIS)

    Wood, J.H.

    1987-01-01

    This book contains 46 chapters divided among nine sections. The section titles are: Historical Perspectives; Cerebrovascular Anatomy; Cerebrovascular Physiology; Methods of Clinical Measurement; Experimental Methods; Imaging of Cerebral Circulation; Cerebrovascular Pathophysiology; Cerebrovascular Pharmacology; and Surgical and Interventional Augmentation

  19. Cerebral time domain-NIRS: Reproducibility analysis, optical properties, hemoglobin species and tissue oxygen saturation in a cohort of adult subjects

    OpenAIRE

    Giacalone, Giacomo; Zanoletti, Marta; Contini, Davide; Rebecca, Re; Spinelli, Lorenzo; Roveri, Luisa; Torricelli, Alessandro

    2017-01-01

    The reproducibility of cerebral time-domain near-infrared spectroscopy (TD-NIRS) has not been investigated so far. Besides, reference intervals of cerebral optical properties, of absolute concentrations of deoxygenated-hemoglobin (HbR), oxygenated-hemoglobin (HbO), total hemoglobin (HbT) and tissue oxygen saturation (StO2) and their variability have not been reported. We have addressed these issues on a sample of 88 adult healthy subjects. TD-NIRS measurements at 690, 785, 830 nm were fitted ...

  20. Analysis of radiocardiographic first pass activity versus time data using models of the central circulation and nonlinear regression analysis

    International Nuclear Information System (INIS)

    Felix, A.C.

    1988-01-01

    In this study mathematical models of the central circulation, containing as undetermined parameters both chamber volumes and crosstalk coefficients, relating region-of-interest count rates to activity no only in the corresponding chamber but also overlapping and contiguous anatomical chambers, were used to identify contaminating crosstalk contributions to the various time-activity curves of interest. The identification of these crosstalks was essential for the creation of decontaminated region-of-interest time-activity curves which could be used for further model analysis. The decontaminated curves represent what the region-of-interest time-activity curves would look like in the absence of crosstalks. An optimal sampling route in was added to the nonlinear regression least squares fit program so that the region-of-interest time-activity curves could be analyzed to determine which data points contributed most toward decreasing the standard error or each parameter. A biplane model was investigated for use in analyzing radionuclide angiocardiographic first pass data

  1. Reconstructing surface ocean circulation with 129I time series records from corals.

    Science.gov (United States)

    Chang, Ching-Chih; Burr, George S; Jull, A J Timothy; Russell, Joellen L; Biddulph, Dana; White, Lara; Prouty, Nancy G; Chen, Yue-Gau; Shen, Chuan-Chou; Zhou, Weijian; Lam, Doan Dinh

    2016-12-01

    The long-lived radionuclide 129 I (half-life: 15.7 × 10 6  yr) is well-known as a useful environmental tracer. At present, the global 129 I in surface water is about 1-2 orders of magnitude higher than pre-1960 levels. Since the 1990s, anthropogenic 129 I produced from industrial nuclear fuels reprocessing plants has been the primary source of 129 I in marine surface waters of the Atlantic and around the globe. Here we present four coral 129 I time series records from: 1) Con Dao and 2) Xisha Islands, the South China Sea, 3) Rabaul, Papua New Guinea and 4) Guam. The Con Dao coral 129 I record features a sudden increase in 129 I in 1959. The Xisha coral shows similar peak values for 129 I as the Con Dao coral, punctuated by distinct low values, likely due to the upwelling in the central South China Sea. The Rabaul coral features much more gradual 129 I increases in the 1970s, similar to a published record from the Solomon Islands. The Guam coral 129 I record contains the largest measured values for any site, with two large peaks, in 1955 and 1959. Nuclear weapons testing was the primary 129 I source in the Western Pacific in the latter part of the 20th Century, notably from testing in the Marshall Islands. The Guam 1955 peak and Con Dao 1959 increases are likely from the 1954 Castle Bravo test, and the Operation Hardtack I test is the most likely source of the 1959 peak observed at Guam. Radiogenic iodine found in coral was carried primarily through surface ocean currents. The coral 129 I time series data provide a broad picture of the surface distribution and depth penetration of 129 I in the Pacific Ocean over the past 60 years. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Enhanced conjugation stability and blood circulation time of macromolecular gadolinium-DTPA contrast agent.

    Science.gov (United States)

    Jenjob, Ratchapol; Kun, Na; Ghee, Jung Yeon; Shen, Zheyu; Wu, Xiaoxia; Cho, Steve K; Lee, Don Haeng; Yang, Su-Geun

    2016-04-01

    In this study, we prepared macromolecular MR T1 contrast agent: pullulan-conjugated Gd diethylene triamine pentaacetate (Gd-DTPA-Pullulan) and estimated residual free Gd(3+), chelation stability in competition with metal ions, plasma and tissue pharmacokinetics, and abdominal MR contrast on rats. Residual free Gd(3+) in Gd-DTPA-Pullulan was measured using colorimetric spectroscopy. The transmetalation of Gd(3+) incubated with Ca(2+) was performed by using a dialysis membrane (MWCO 100-500 Da) and investigated by ICP-OES. The plasma concentration profiles of Gd-DTPA-Pullulan were estimated after intravenous injection at a dose 0.1 mmol/kg of Gd. The coronal-plane abdominal images of normal rats were observed by MR imaging. The content of free Gd(3+), the toxic residual form, was less than 0.01%. Chelation stability of Gd-DTPA-Pullulan was estimated, and only 0.2% and 0.00045% of Gd(3+) were released from Gd-DTPA-Pullulan after 2h incubation with Ca(2+) and Fe(2+), respectively. Gd-DTPA-Pullulan displayed the extended plasma half-life (t1/2,α=0.43 h, t1/2,β=2.32 h), much longer than 0.11h and 0.79 h of Gd-EOB-DTPA. Abdominal MR imaging showed Gd-DTPA-Pullulan maintained initial MR contrast for 30 min. The extended plasma half-life of Gd-DTPA-Pullulan probably allows the prolonged MR acquisition time in clinic with enhanced MR contrast. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Malaria cerebral Cerebral malaria

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    Carlos Hugo Zapata Zapata

    2003-03-01

    Full Text Available La malaria Cerebral (MC es la complicación más frecuente de la malaria por P. falciparum; aproximadamente el 90% de las personas que la han padecido se recuperan completamente sin secuelas neurológicas. Aún no se conoce con claridad su patogénesis pero se han postulado cuatro hipótesis o mecanismos posibles: 1 citoadherencia y secuestro de glóbulos rojos parasitados en la microvasculatura cerebral; 2 formación de rosetas y aglutinación de glóbulos rojos parasitados; 3 producción de citoquinas y activación de segundos mensajeros y, 4 apertura de la barrera hematoencefálica. Sin embargo, queda un interrogante sin resolver aún: ¿qué proceso se lleva a cabo para que el parásito, desde el espacio microvascular, pueda interferir transitoriamente con la función cerebral? Recientemente se ha utilizado el precursor de la proteína b-Amiloide como un marcador de daño neuronal en MC; este precursor será de gran ayuda en futuras investigaciones realizadas en nuestro medio que aporten información para comprender la patogénesis de la MC. Is the most common complication of P. falciparum malaria; nearly 90% of people who have suffered CM can recover without neurological problems. Currently there are four hypotheses that explain pathogenesis of CM: cytoadherence and sequestering of parasitized red blood cells to cerebral capillaries; rosette formation and parasitized red blood cells agglutination; production of cytokines and activation of second messengers and opening of the blood-brain barrier. However the main question remains to be answered; how the host-parasite interaction in the vascular space interferes transiently with cerebral function? Recently, the beta amyloid precursor peptide has been employed as marker of neural injury in CM. It is expected that the beta amyloid precursor peptide will help to understand the pathogenesis of CM in complicated patients of endemic areas of Colombia.

  4. A comparative study of peripheral to central circulation delivery times between intraosseous and intravenous injection using a radionuclide technique in normovolemic and hypovolemic canines

    International Nuclear Information System (INIS)

    Cameron, J.L.; Fontanarosa, P.B.; Passalaqua, A.M.

    1989-01-01

    Intraosseous infusion is considered a useful technique for administration of medications and fluids in emergency situations when peripheral intravascular access is unobtainable. This study examined the effectiveness of intraosseous infusion for delivery of substances to the central circulation. Central deliveries of a radionuclide tracer administered by the intraosseous and intravenous routes were evaluated during normovolemic and hypovolemic states. Intraosseous infusion achieved peripheral to central circulation transit times comparable to those achieved by the intravenous route. Analysis of variance revealed no statistically significant differences between the peripheral to central delivery times comparing intraosseous and intravenous administration. The results demonstrate that intraosseous infusion is a rapid and effective method of delivery to the central circulation and is an alternative method for intravascular access. This study also suggests that a radionuclide tracer is useful for the evaluation of transit times following intraosseous injection

  5. Fast mapping of the T2 relaxation time of cerebral metabolites using proton echo-planar spectroscopic imaging (PEPSI).

    Science.gov (United States)

    Tsai, Shang-Yueh; Posse, Stefan; Lin, Yi-Ru; Ko, Cheng-Wen; Otazo, Ricardo; Chung, Hsiao-Wen; Lin, Fa-Hsuan

    2007-05-01

    Metabolite T2 is necessary for accurate quantification of the absolute concentration of metabolites using long-echo-time (TE) acquisition schemes. However, lengthy data acquisition times pose a major challenge to mapping metabolite T2. In this study we used proton echo-planar spectroscopic imaging (PEPSI) at 3T to obtain fast T2 maps of three major cerebral metabolites: N-acetyl-aspartate (NAA), creatine (Cre), and choline (Cho). We showed that PEPSI spectra matched T2 values obtained using single-voxel spectroscopy (SVS). Data acquisition for 2D metabolite maps with a voxel volume of 0.95 ml (32 x 32 image matrix) can be completed in 25 min using five TEs and eight averages. A sufficient spectral signal-to-noise ratio (SNR) for T2 estimation was validated by high Pearson's correlation coefficients between logarithmic MR signals and TEs (R2 = 0.98, 0.97, and 0.95 for NAA, Cre, and Cho, respectively). In agreement with previous studies, we found that the T2 values of NAA, but not Cre and Cho, were significantly different between gray matter (GM) and white matter (WM; P PEPSI and SVS scans was less than 9%. Consistent spatial distributions of T2 were found in six healthy subjects, and disagreement among subjects was less than 10%. In summary, the PEPSI technique is a robust method to obtain fast mapping of metabolite T2. (c) 2007 Wiley-Liss, Inc.

  6. Comparison of time-resolved and continuous-wave near-infrared techniques for measuring cerebral blood flow in piglets

    Science.gov (United States)

    Diop, Mamadou; Tichauer, Kenneth M.; Elliott, Jonathan T.; Migueis, Mark; Lee, Ting-Yim; Lawrence, Keith St.

    2010-09-01

    A primary focus of neurointensive care is monitoring the injured brain to detect harmful events that can impair cerebral blood flow (CBF), resulting in further injury. Since current noninvasive methods used in the clinic can only assess blood flow indirectly, the goal of this research is to develop an optical technique for measuring absolute CBF. A time-resolved near-infrared (TR-NIR) apparatus is built and CBF is determined by a bolus-tracking method using indocyanine green as an intravascular flow tracer. As a first step in the validation of this technique, CBF is measured in newborn piglets to avoid signal contamination from extracerebral tissue. Measurements are acquired under three conditions: normocapnia, hypercapnia, and following carotid occlusion. For comparison, CBF is concurrently measured by a previously developed continuous-wave NIR method. A strong correlation between CBF measurements from the two techniques is revealed with a slope of 0.79+/-0.06, an intercept of -2.2+/-2.5 ml/100 g/min, and an R2 of 0.810+/-0.088. Results demonstrate that TR-NIR can measure CBF with reasonable accuracy and is sensitive to flow changes. The discrepancy between the two methods at higher CBF could be caused by differences in depth sensitivities between continuous-wave and time-resolved measurements.

  7. Cerebral cortex activation mapping upon electrical muscle stimulation by 32-channel time-domain functional near-infrared spectroscopy.

    Science.gov (United States)

    Re, Rebecca; Muthalib, Makii; Contini, Davide; Zucchelli, Lucia; Torricelli, Alessandro; Spinelli, Lorenzo; Caffini, Matteo; Ferrari, Marco; Quaresima, Valentina; Perrey, Stephane; Kerr, Graham

    2013-01-01

    The application of different EMS current thresholds on muscle activates not only the muscle but also peripheral sensory axons that send proprioceptive and pain signals to the cerebral cortex. A 32-channel time-domain fNIRS instrument was employed to map regional cortical activities under varied EMS current intensities applied on the right wrist extensor muscle. Eight healthy volunteers underwent four EMS at different current thresholds based on their individual maximal tolerated intensity (MTI), i.e., 10 % < 50 % < 100 % < over 100 % MTI. Time courses of the absolute oxygenated and deoxygenated hemoglobin concentrations primarily over the bilateral sensorimotor cortical (SMC) regions were extrapolated, and cortical activation maps were determined by general linear model using the NIRS-SPM software. The stimulation-induced wrist extension paradigm significantly increased activation of the contralateral SMC region according to the EMS intensities, while the ipsilateral SMC region showed no significant changes. This could be due in part to a nociceptive response to the higher EMS current intensities and result also from increased sensorimotor integration in these cortical regions.

  8. Cerebral microangiopathies

    International Nuclear Information System (INIS)

    Linn, Jennifer

    2011-01-01

    Cerebral microangiopathies are a very heterogenous group of diseases characterized by pathological changes of the small cerebral vessels. They account for 20 - 30 % of all ischemic strokes. Degenerative microangiopathy and sporadic cerebral amyloid angiography represent the typical acquired cerebral microangiopathies, which are found in over 90 % of cases. Besides, a wide variety of rare, hereditary microangiopathy exists, as e.g. CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy), Fabrys disease and MELAS syndrome (Mitochondrial myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like episodes). (orig.)

  9. Analysis of arterial pressure variability in patients with acute cerebral stroke depending on the time of occurrence

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    Volosovets A.O.

    2017-12-01

    Full Text Available Arterial hypertension can cause a pronounced negative influence on the state of the cerebral vascular system and lead to significant microtraumatization of the walls of the vessels and disruption of vascular autoregulation. This predictor has the greatest influence on the onset of ischemic stroke of atherothrombotic and lacunar subtypes, however, hypertension occurs almost in all patients with acute cerebral ischemia. Interesting and not at all presented in modern scientific literature is the question of the relationship of oscillation of blood pressure with the period of the onset of the focus of ischemia, which predetermined the purpose of our work. The purpose of our study was to determine the relationship between deformation of the profile of fluctuations in blood pressure of patients in the acute period of ischemic stroke, depending on the time of the occurrence of cerebrovascular accident. We examined 300 patients who suffered acute ischemic stroke (men - 196, women - 104 aged 42 to 84 years (average age - 65.2 ± 8.7 years. All patients were divided into 3 groups according to the period of the day when an ischemic stroke occurred: 1 group (n=146, patients suffering from cerebral ischemia during the day (8.00-14.59; In group 2 (n=107, patients stroke was observed in the evening (15.00-21.59; Group 3 (n=47, patients had an ischemic stroke at night (22.00-7.59. For the 1st group of patients who have had ischemic stroke during the day and as a rule with an increase in blood pressure, a marked increase in blood pressure was at 12.00 and 15.00 and a tendency towards compensatory parasympathetic effect in the form of blood pressure decrease at night (over-dipper was typical. At the same time, in the 2nd group of patients with stroke in the evening, elevated blood pressure at 18.00 and 21.00 and parasympathetic activity disorders with prevalence of insufficient reduction of blood pressure in the evening and during sleep (non-dipper was observed

  10. Impact of time to return of spontaneous circulation on neuroprotective effect of targeted temperature management at 33 or 36 degrees in comatose survivors of out-of hospital cardiac arrest.

    Science.gov (United States)

    Kjaergaard, Jesper; Nielsen, Niklas; Winther-Jensen, Matilde; Wanscher, Michael; Pellis, Tommaso; Kuiper, Michael; Hartvig Thomsen, Jakob; Wetterslev, Jørn; Cronberg, Tobias; Bro-Jeppesen, John; Erlinge, David; Friberg, Hans; Søholm, Helle; Gasche, Yvan; Horn, Janneke; Hovdenes, Jan; Stammet, Pascal; Wise, Matthew P; Åneman, Anders; Hassager, Christian

    2015-11-01

    Time to Return of Spontaneous Circulation (ROSC) has a plausible relation to severity of hypoxic injury before and during resuscitation in Out-of-Hospital Cardiac Arrest (OHCA), and has consistently been associated with adverse outcome. The effect of Targeted Temperature Management (TTM) may not be similar over the full spectrum of time to ROSC. This study investigated the possible beneficial effect of targeting 33°C over 36°C on the prognostic importance of time to ROSC. In predefined sub-study of the TTM-trial (NEJM 2013) we investigated the relationship between time to ROSC, level of TTM and mortality and neurological outcome as assessed by the Cerebral Performance Category (CPC) scale and modified Rankin Scale (mRS) after 180 days. Prolonged time to ROSC was significantly associated with increased mortality with a hazard ratio (HR) of 1.02 per minute (95% CI 1.01-1.02). Level of TTM did not modify the association of time to ROSC and mortality, pinteraction=0.85. Prolonged time to ROSC was associated with reduced odds of surviving with a favorable neurological outcome for CPC (p=0.008 for CPC 1-2) and mRS (p=0.17, mRS 0-3) with no significant interaction with level of TTM. Time to ROSC remains a significant prognostic factor in comatose OHCA patients with regards to risk of death and risk of adverse neurological outcome. For any time to ROSC, targeting 33°C in TTM was not associated with benefit with regards to reducing mortality or risk of adverse neurological outcome compared to targeting 36°C. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. Placental release of distinct DNA-associated microparticles into maternal circulation: reflective of gestation time and preeclampsia

    Science.gov (United States)

    Orozco, Aaron F.; Jorgez, Carolina J.; Ramos-Perez, William D.; Popek, Edwina J.; Yu, Xiaoying; Kozinetz, Claudia A.; Bischoff, Farideh Z.; Lewis, Dorothy E.

    2009-01-01

    Background The aim of this study was to determine whether DNA-associated micro-particles (MPs) in maternal plasma express fetal-derived human leukocyte antigen-G (HLA-G) or placental alkaline phosphatase (PLAP) and whether the levels differ between women with normotensive pregnancies and preeclampsia. Methods DNA-associated MPs expressing HLA-G or PLAP were examined in the plasma of normal pregnant women and preeclamptic patients using flow cytometric analysis. Results DNA-associated HLA-G+ MPs were significantly increased in maternal plasma compared to plasma from non-pregnant controls (p < 0.005), with highest levels found in first and second trimesters. DNA-associated PLAP+ MPs were also increased in maternal plasma compared to plasma from non-pregnant controls (p < 0.006), with highest levels in second and third trimesters. Term preeclamptic women had higher levels of DNA-associated MPs than control pregnant women. HLA-G+ MPs from the plasma of preeclamptic women had more DNA per MP than HLA-G+ MPs from the plasma of normal pregnant women (p < 0.03). Conclusions HLA-G and PLAP MPs increase in maternal circulation at different times during gestation. DNA amounts per HLA-G+ MP increase in preeclamptic women which might indicate dysfunctional extravillous cytotrophoblasts. PMID:19692120

  12. Meteorologic, oceanographic, and geomorphic controls on circulation and residence time in a coral reef-lined embayment: Faga'alu Bay, American Samoa

    Science.gov (United States)

    Storlazzi, C. D.; Cheriton, O. M.; Messina, A. M.; Biggs, T. W.

    2018-06-01

    Water circulation over coral reefs can determine the degree to which reef organisms are exposed to the overlying waters, so understanding circulation is necessary to interpret spatial patterns in coral health. Because coral reefs often have high geomorphic complexity, circulation patterns and the duration of exposure, or "local residence time" of a water parcel, can vary substantially over small distances. Different meteorologic and oceanographic forcings can further alter residence time patterns over reefs. Here, spatially dense Lagrangian surface current drifters and Eulerian current meters were used to characterize circulation patterns and resulting residence times over different regions of the reefs in Faga'alu Bay, American Samoa, during three distinct forcing periods: calm, strong winds, and large waves. Residence times varied among different geomorphic zones of the reef and were reflected in the spatially varying health of the corals across the embayment. The relatively healthy, seaward fringing reef consistently had the shortest residence times, as it was continually flushed by wave breaking at the reef crest, whereas the degraded, sheltered, leeward fringing reef consistently had the longest residence times, suggesting this area is more exposed to land-based sources of pollution. Strong wind forcing resulted in the longest residence times by pinning the water in the bay, whereas large wave forcing flushed the bay and resulted in the shortest residence times. The effect of these different forcings on residence times was fairly consistent across all reef geomorphic zones, with the shift from wind to wave forcing shortening mean residence times by approximately 50%. Although ecologically significant to the coral organisms in the nearshore reef zones, these shortened residence times were still 2-3 times longer than those associated with the seaward fringing reef across all forcing conditions, demonstrating how the geomorphology of a reef environment sets a

  13. Multi-scale approach to Euro-Atlantic climatic cycles based on phenological time series, air temperatures and circulation indexes.

    Science.gov (United States)

    Mariani, Luigi; Zavatti, Franco

    2017-09-01

    The spectral periods in North Atlantic Oscillation (NAO), Atlantic Multidecadal Oscillation (AMO) and El Nino Southern Oscillation (ENSO) were analyzed and has been verified how they imprint a time series of European temperature anomalies (ETA), two European temperature time series and some phenological series (dates of cherry flowering and grapevine harvest). Such work had as reference scenario the linear causal chain MCTP (Macroscale Circulation→Temperature→Phenology of crops) that links oceanic and atmospheric circulation to surface air temperature which in its turn determines the earliness of appearance of phenological phases of plants. Results show that in the three segments of the MCTP causal chain are present cycles with the following central period in years (the % of the 12 analyzed time series interested by these cycles are in brackets): 65 (58%), 24 (58%), 20.5 (58%), 13.5 (50%), 11.5 (58%), 7.7 (75%), 5.5 (58%), 4.1 (58%), 3 (50%), 2.4 (67%). A comparison with short term spectral peaks of the four El Niño regions (nino1+2, nino3, nino3.4 and nino4) show that 10 of the 12 series are imprinted by periods around 2.3-2.4yr while 50-58% of the series are imprinted by El Niño periods of 4-4.2, 3.8-3.9, 3-3.1years. The analysis highlights the links among physical and biological variables of the climate system at scales that range from macro to microscale whose knowledge is crucial to reach a suitable understanding of the ecosystem behavior. The spectral analysis was also applied to a time series of spring - summer precipitation in order to evaluate the presence of peaks common with other 12 selected series with result substantially negative which brings us to rule out the existence of a linear causal chain MCPP (Macroscale Circulation→Precipitation→Phenology). Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Time-course changes in circulating branched-chain amino acid levels and metabolism in obese Yucatan minipig.

    Science.gov (United States)

    Polakof, Sergio; Rémond, Didier; David, Jérémie; Dardevet, Dominique; Savary-Auzeloux, Isabelle

    2018-06-01

    High-fat high-sucrose diet (HFHS) overfeeding is one of the main factors responsible for the increased prevalence of metabolic disorders. Elevated levels of branched-chain amino acids (BCAAs) have been associated with metabolic dysfunctions, including insulin resistance (IR). The aim of this study was to elucidate whether elevated BCAA levels are the cause or the consequence of IR and to determine the mechanisms and tissues involved in such a phenotype. We performed a 2-mo follow-up on minipigs overfed an HFHS diet and focused on kinetics fasting and postprandial (PP) BCAA levels and BCAA catabolism in key tissues. The study of the fasting BCAA elevation reveals that BCAA accumulation in the plasma compartment is well correlated with IR markers and body weight. Furthermore, the PP excursion of BCAA levels after the last HFHS meal was exacerbated when compared with that of the first meal, suggesting a reduced amino acid oxidation potential. Although only minor changes in BCAA metabolism were observed in liver, muscle, and the visceral adipose tissue, the oxidative deamination potential of the subcutaneous adipose tissue was blunted after 60 d of HFHS feeding. To our knowledge, the present results demonstrated for the first time in a swine model of obesity and IR, the existence of a phenotype related to high-circulating BCAA levels and metabolic dysregulation. The oxidative BCAA capacity reduction specifically in the subcutaneous adipose tissue emerges, at least in the present swine model, as the more plausible metabolic explanation for the elevated blood BCAA phenotype. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. The circulation of Ghlin flint during the time of the Blicquy - Villeneuve-Saint-Germain culture (Early Neolithic

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    Solène Denis

    2014-03-01

    Full Text Available In the North of France and Belgium, the Blicquy - Villeneuve-Saint-Germain culture marks the end of the Early Neolithic Period (beginning of the 5th millennium. The Blicquy group is constituted of eleven sites located in Belgium, with two main centers of occupation: one Western in Hainaut and one Eastern in Hesbaye, 100 km away from the first. As part of a PhD, the lithic industry of these sites is studied in order to reconstruct the circulation networks through a techno-economic analysis. It has been complex to identify the raw materials, given the lack of information about the siliceous outcrops in the Mons Basin. However, two main circulation networks have been highlighted: one of Ghlin flint and one of tertiary Bartonian flint. These two types of flint are indeed easily recognizable by their macroscopic characteristics. The outcrops of tertiary Bartonian flints originate from the Paris Basin, where systematic surveys have been conducted since the late 1980s. The circulation of tertiary Bartonian flint is now well-known and emblematic of the Blicquy - Villeneuve-Saint-Germain culture. Therefore, this paper will focus on the circulation of Ghlin flint in the Blicquy-Villeneuve-Saint-Germain culture. The Ghlin flint shows on the surface in the Mons Basin, about twenty kilometers away from the Hainaut sites. Heavily exploited in the latter, it was exported to the Hesbaye sites in a significant way, despite the availability of siliceous resources available in Hesbaye. Moreover, some artifacts circulated towards the Paris Basin. The study of the circulation of Ghlin flint can therefore help to determine the socio-economic organization of these populations by specifying the linkages between the population centers of Hainaut, Hesbaye and Paris Basin.

  16. Time course of radiolabeled 2-deoxy-D-glucose 6-phosphate turnover in cerebral cortex of goats

    International Nuclear Information System (INIS)

    Pelligrino, D.A.; Miletich, D.J.; Albrecht, R.F.

    1987-01-01

    The vivo dephosphorylation rate of 2-deoxy-D-glucose 6-phosphate (DGP) in the cerebral cortex of goats injected intravenously with radiolabeled 2-deoxy-D-glucose (DG) was investigated. Serial rapidly frozen samples of parietal cortical gray tissue were obtained at regular intervals over time periods from 45 min to 3 h in awake goats or in paralyzed and artificially ventilated goats maintained under 70% N 2 O or pentobarbital sodium anesthesia. The samples were analyzed for glucose content and separate DG and DGP activities. The rate parameters for phosphorylation (k/sup */ 4 ) and dephosphorylation (k/sup */ 4 ) were estimated in each animal. The glucose phosphorylation rate (PR) was calculated over the intervals 3-5 (or 6), 3-10, 3-20, 3-30, and 3-45 min, assuming k/sup */ 4 = O. As the evaluation period was extended beyond 10 min, the calculated PR became increasingly less when compared with that calculated over the 3- to 5- (or 6) min interval (PR/sub i/). Furthermore, as metabolic activity decreased, the magnitude of the error increased such that at 45 min pentobarbital-anesthetize goats underestimated the PR/sub i/ by 46.5% compared with only 23.1 in N 2 O-anesthetized goats. This was also reflected in the >twofold higher k/sup */ 4 /k/sup */ 3 ratio in the pentobarbital vs. N 2 O-anesthetized group. It is concluded that when using the DG method in the goat, DGP dephosphorylation cannot be ignored when employing >10-min evaluation periods

  17. Emprego da nimodipina (oxigen como protetor cerebral na cirurgia de revascularização do miocárdio com circulação extracorpórea em pacientes idosos Use of nimodipine for cerebral injury prophylaxis in surgical myocardial revascularization with extracorporeal circulation in elderly patients

    Directory of Open Access Journals (Sweden)

    Ricardo Manrique

    1996-12-01

    Full Text Available Aproximadamente 5% dos pacientes submetidos a cirurgia cardíaca com auxílio da circulação extracorpórea apresentaram problemas neurológicos. Avaliando funções neuropsíquicas, as alterações atingem de 50% a 70% dos casos. Os idosos são mais vulneráveis; nestes, a freqüência de acidente vascular cerebral (AVC aproxima-se dos 9%. Considerando que a população envelhece a um ritmo acelerado e que 0 coronariopata freqüentemente passa dos 65 anos de idade, é fundamental pesquisar meios profiláticos para diminuir esta incidência. Este é um estudo piloto, duplo cego, randomizado e controlado com 64 pacientes, 30 no Grupo nimodipina e 34 no Grupo placebo. As variáveis demográficas e diagnosticas pré-operatórias foram homogêneas, com exceção da incidência de isquemia cerebral transitória. O Grupo nimodipina, mesmo com programação cirúrgica e evolução intra e pós-operatória mais complicadas, apresentou menor número de casos neurológicos. No Grupo nimodipina foram constatados 3 casos de confusão mental e, no Grupo placebo, além de 3 casos de confusão mental, foram diagnosticados mais 2 casos de sonolência e 1 AVC isquêmico com seqüela. No total, foram 3 (10% casos em 30 pacientes no Grupo nimodipina, e 6 (17,64% em 34 pacientes no Grupo placebo, caracterizando uma redução de 76,4%. LEGAULT et al. (15 relatam uma elevada mortalidade de pacientes em uso de nimodipina, quando operados para troca valvar, causada, principalmente, por hemorragia. Nós não encontramos esta correlação. A mortalidade hospitalar é similar em ambos os grupos (1 paciente em cada e o sangramento não é estatisticamente diferente (1 caso de hemorragia importante no Grupo nimodipina. No seguimento até 41 meses, a mortalidade no Grupo placebo foi maior (4 pacientes que no Grupo nimodipina (1 paciente.Around 5 percent of the patients submitted to heart surgery with extracorporeal circulation present neurological problems. In relation to

  18. Reliability of perfusion MR imaging in symptomatic carotid occlusive disease. Cerebral blood volume, mean transit time and time-to-peak

    International Nuclear Information System (INIS)

    Kim, J.H.; Lee, E.J.; Lee, S.J.; Choi, N.C.; Lim, B.H.; Shin, T.

    2002-01-01

    Purpose: Perfusion MR imaging offers an easy quantitative evaluation of relative regional cerebral blood volume (rrCBV), relative mean transit time (rMTT) and time-to-peak (TTP). The purpose of this study was to investigate the reliability of these parameters in assessing the hemodynamic disturbance of carotid occlusive disease in comparison with normative data. Material and Methods: Dynamic contrast-enhanced T2*-weighted perfusion MR imaging was performed in 19 patients with symptomatic unilateral internal carotid artery occlusion and 20 control subjects. The three parameters were calculated from the concentration-time curve fitted by gamma-variate function. Lesion-to-contralateral ratios of each parameter were compared between patients and control subjects. Results: Mean±SD of rrCBV, rMTT and TTP ratios of patients were 1.089±0.118, 1.054±0.031 and 1.062±0.039, respectively, and those of control subjects were 1.002±0.045, 1.000±0.006, 1.001±0.006, respectively. The rMTT and TTP ratios of all patients were greater than 2SDs of control data, whereas in only 6 patients (32%), rrCBV ratios were greater than 2SDs of control data. The three parameter ratios of the patients were significantly high compared with those of control subjects, respectively (p<0.01 for rrCBV ratios, p<0.0001 for rMTT ratios, and p<0.0001 for TTP ratios). Conclusion: Our results indicate that rMTT and TTP of patients, in contrast to rrCBV, are distributed in narrow ranges minimally overlapped with control data. The rMTT and TTP could be more reliable parameters than rrCBV in assessing the hemodynamic disturbance in carotid occlusive disease

  19. Cerebral vasculitis

    International Nuclear Information System (INIS)

    Greenan, T.J.; Grossman, R.I.

    1990-01-01

    This paper reviews retrospectively MR, CT, and angiographic findings in patients with cerebral vasculitis in order to understand the strengths and weaknesses of the various imaging modalities, as well as the spectrum of imaging abnormalities in this disease entity. Studies were retrospectively reviewed in 12 patients with cerebral vasculitis proved by means of angiography and/or brain biopsy

  20. Relationships among Ocular Blood Flow Shown by Laser Speckle Flowgraphy, Retinal Arteriosclerotic Change, and Chorioretinal Circulation Time Obtained by Fluorescein Angiography

    Directory of Open Access Journals (Sweden)

    Hironori Osamura

    2017-01-01

    Full Text Available Purpose. To determine the correlations among the mean blur rate (MBR in the optic nerve head (ONH shown by laser speckle flowgraphy (LSFG, retinal arteriosclerosis, and the circulation time obtained by fluorescein angiography (FA. Method. We evaluated 118 patients and assessed their time of choroidal flush, arm-to-retina time, and early and late phases of retinal circulation time (RT: sec obtained by FA. The severity of retinal arteriosclerosis was classified according to the Scheie classification. The MBR values throughout the ONH (MBR-A, in the tissue (MBR-T, and in the vessels (MBR-V were analyzed. Results. Patients with retinal vein occlusion (RVO showed prolonged early and late phases of RT compared to other ocular diseases. Single and multiple regression analyses showed that the MBR-V and Scheie classification were significantly associated with both the choroidal flush and arm-to-retina times. The incidences of RVO and MVR-V were significantly associated with the early phase of RT, and the incidences of RVO, MBR-V, Scheie classification, and gender were revealed to be factors independently contributing to the late phase of RT. Conclusion. MBR-V in the ONH and retinal arteriosclerosis are important contributing factors for the circulation time of each stage obtained by FA.

  1. Sentinel site-enhanced near-real time surveillance documenting West Nile virus circulation in two Culex mosquito species indicating different transmission characteristics, Djibouti City, Djibouti.

    Science.gov (United States)

    Faulde, Michael K; Spiesberger, Michael; Abbas, Babiker

    2012-08-01

    The Horn of Africa represents a region formerly known to be highly susceptible to mosquito-borne infectious diseases. In order to investigate whether autochthonous WNV transmission occurs in the Djibouti City area, in how far, and which of, the endemic Culex mosquito species are involved in WNV circulation activity,and whether sentinel site-enhanced near-real time surveillance (SSE-NRTS) may increase WNV detection sensitivity, mosquito vector monitoring was conducted from January 2010 to June 2012. Six monitoring locations, including two identified sentinel sites, considered most probable for potential anthroponotic and zoonotic virus circulation activity, have been continuously employed. Among the 20431 mosquitoes collected, 19069 (93.4%) were Cx. quinquefasciatus, and 1345 (6.6%) Cx. pipiens ssp. torridus. WNV lineage 2 circulation activity was detected between December 20th, 2010 and January 7th, 2011. Overall, 19 WNV RNA-positive mosquito pools were detected. Generally, urban environment-specific WNV-RNA circulation took place in Cx. pipiens ssp. torridus, whereas periurban and rural area-linked circulation was detected only in Cx. quinquefasciatus. Serological investigation data from 10 volunteers employed at the dislocated zoonotic WNV transmission sentinel site suggest that six persons (60%) had an acute, or recent, WNV infection. Results show that WNV should be considered endemic for Djibouti and sentinel site-enhanced near-real time surveillance is an elegant and highly effective epidemiological tool. In Djibouti, the endemicity level, public health impact and transmission modes of vector-borne diseases in concordance with locally optimized monitoring and control regimen deserve further investigation.

  2. A comparison of four dimensional time-resolved with keyhole and three dimensional time-of-flight MR angiography for the evaluation of cerebral aneurysms

    International Nuclear Information System (INIS)

    Wu Qian; Li Minghua; Zhang Jiayin; Li Yongdong

    2012-01-01

    Objective: To evaluate the accuracy and reliability of 4D time-resolved MRA with keyhole (4D-TRAK) for the detection and characterization of cerebral aneurysms (CAs), with a comparison of 3D time-of-flight MRA (3D-TOF-MRA). Methods: 3D-TOF-MRA, 4D-TRAK and 3D-DSA were performed sequentially in 52 patients with suspected CAs. 4D-TRAK was acquired using a combination of sensitivity encoding (SENSE) and contrast-enhanced (CE) timing robust angiography (CENTRA) k-space sampling techniques at a contrast dose of 10 ml at 3 T scanner. Accuracy, sensitivity, specificity of 4D-TRAK and 3D-TOF-MRA were calculated and compared for the detection of CAs on patient-based and aneurysm-based evaluation using 3D-DSA as a reference. Wilcoxon signed rank test were used. Results: The overall image quality of 4D-TRAK was appropriate for the diagnostic purpose, but yet not comparable with that of 3D-TOF-MRA. In 52 patients with suspected GAs, 58 CAs were confirmed on 3D-DSA finally.Fifty-one (with 2 false-positives and 9 false-negatives) and 58 (with 1 false-positive and 1 false-negative) CAs were visualized on 4D-TRAK and 3D-TOF-MRA, respectively. Accuracy, sensitivity and specificity on patient-based evaluation of 4D-TRAK and 3D-TOF-MRA were 92.31% (48/52), 93.33% (42/45), 85.71 % (6/7) and 98.08% (51/52), 100.00% (45/45), 85.71% (6/7), respectively, and 74.07% (20/27), 75.00% (18/24), 66.67% (2/3) and 96.30% (26/27), 95.83% (26/27), 100.00% (3/3) on aneurysm-based evaluation in patients with multiple CAs, respectively. Subgroup analysis revealed that for 19 very small CAs (maximal diameter <3 mm,measured on 3D-DSA), 9 were missed on 4D-TRAK and 1 on 3D-TOF-MRA (Z=-2.464, P0.05). In 4 large CAs with maximal diameter more than 10 mm, 4D-TRAK provided a better characterization of morphology than 3D

  3. Revisiting the circulation time of Plasmodium falciparum gametocytes: molecular detection methods to estimate the duration of gametocyte carriage and the effect of gametocytocidal drugs

    Directory of Open Access Journals (Sweden)

    Sawa Patrick

    2010-05-01

    Full Text Available Abstract Background There is renewed acknowledgement that targeting gametocytes is essential for malaria control and elimination efforts. Simple mathematical models were fitted to data from clinical trials in order to determine the mean gametocyte circulation time and duration of gametocyte carriage in treated malaria patients. Methods Data were used from clinical trials from East Africa. The first trial compared non-artemisinin combination therapy (non-ACT: sulphadoxine-pyrimethamine (SP plus amodiaquine and artemisinin-based combination therapy (ACT: SP plus artesunate (AS or artemether-lumefantrine. The second trial compared ACT (SP+AS with ACT in combination with a single dose of primaquine (ACT-PQ: SP+AS+PQ. Mature gametocytes were quantified in peripheral blood samples by nucleic acid sequence based amplification. A simple deterministic compartmental model was fitted to gametocyte densities to estimate the circulation time per gametocyte; a similar model was fitted to gametocyte prevalences to estimate the duration of gametocyte carriage after efficacious treatment. Results The mean circulation time of gametocytes was 4.6-6.5 days. After non-ACT treatment, patients were estimated to carry gametocytes for an average of 55 days (95% CI 28.7 - 107.7. ACT reduced the duration of gametocyte carriage fourfold to 13.4 days (95% CI 10.2-17.5. Addition of PQ to ACT resulted in a further fourfold reduction of the duration of gametocyte carriage. Conclusions These findings confirm previous estimates of the circulation time of gametocytes, but indicate a much longer duration of (low density gametocyte carriage after apparently successful clearance of asexual parasites. ACT shortened the period of gametocyte carriage considerably, and had the most pronounced effect on mature gametocytes when combined with PQ.

  4. A Nonlinear Dynamic Approach Reveals a Long-Term Stroke Effect on Cerebral Blood Flow Regulation at Multiple Time Scales

    Science.gov (United States)

    Hu, Kun; Lo, Men-Tzung; Peng, Chung-Kang; Liu, Yanhui; Novak, Vera

    2012-01-01

    Cerebral autoregulation (CA) is an important vascular control mechanism responsible for relatively stable cerebral blood flow despite changes of systemic blood pressure (BP). Impaired CA may leave brain tissue unprotected against potentially harmful effects of BP fluctuations. It is generally accepted that CA is less effective or even inactive at frequencies >∼0.1 Hz. Without any physiological foundation, this concept is based on studies that quantified the coupling between BP and cerebral blood flow velocity (BFV) using transfer function analysis. This traditional analysis assumes stationary oscillations with constant amplitude and period, and may be unreliable or even invalid for analysis of nonstationary BP and BFV signals. In this study we propose a novel computational tool for CA assessment that is based on nonlinear dynamic theory without the assumption of stationary signals. Using this method, we studied BP and BFV recordings collected from 39 patients with chronic ischemic infarctions and 40 age-matched non-stroke subjects during baseline resting conditions. The active CA function in non-stroke subjects was associated with an advanced phase in BFV oscillations compared to BP oscillations at frequencies from ∼0.02 to 0.38 Hz. The phase shift was reduced in stroke patients even at > = 6 months after stroke, and the reduction was consistent at all tested frequencies and in both stroke and non-stroke hemispheres. These results provide strong evidence that CA may be active in a much wider frequency region than previously believed and that the altered multiscale CA in different vascular territories following stroke may have important clinical implications for post-stroke recovery. Moreover, the stroke effects on multiscale cerebral blood flow regulation could not be detected by transfer function analysis, suggesting that nonlinear approaches without the assumption of stationarity are more sensitive for the assessment of the coupling of nonstationary

  5. Clinical application of cerebral dynamic perfusion studies

    International Nuclear Information System (INIS)

    DeLand, F.H.

    1975-01-01

    Radionuclide cerebral perfusion studies are assuming a far greater importance in the detection and differential diagnosis of cerebral lesions. Perfusion studies not only contribute to the differential diagnosis of lesions but in certain cases are the preferred methods by which more accurate clinical interpretations can be made. The characteristic blood flow of arterio-venous malformations readily differentiates this lesion from neoplasms. The decreased perfusion or absent perfusion observed in cerebral infarctions is diagnostic without concurrent evidence from static images. Changes in rates and direction of blood flow contribute fundamental information to the status of stenosis and vascular occlusion and, in addition, offer valuable information on the competency and routes of collateral circulation. The degree of cerebral perfusion after cerebral vascular accidents appears to be directly related to patient recovery, particularly muscular function. Cerebral perfusion adds a new parameter in the diagnosis of subdural haematomas and concussion and in the differentiation of obscuring radioactivity from superficial trauma. Although pictorial displays of perfusion blood flow will offer information in most cerebral vascular problems, the addition of computer analysis better defines temporal relationships of regional blood flow, quantitative changes in flow and the detection of the more subtle increases or decreases in cerebral blood flow. The status of radionuclide cerebral perfusion studies has taken on an importance making it the primary modality for the diagnosis of cerebral lesions. (author)

  6. Dynamic CT brain scanning in the haemodynamic evaluation of cerebral arterial occlusive disease

    International Nuclear Information System (INIS)

    Davis, S.M.; Melbourne Univ.; Tress, B.M.; Hopper, J.L.; Rossiter, S.C.; Kaye, A.H.

    1987-01-01

    Dynamic cerebral CT scanning (DCT) was used to quantitatively analyse the haemodynamic effects of extracranial and intracranial arterial occlusive lesions in 17 patients with TIA's or minor cerebral infarcts. Using DCT and gamma variate curve fitting, mean transit times were determined for the terminal internal carotid arteries, middle cerebral arteries and middle cerebral-supplied Sylvian cortex at the level of the Circle of Willis. Six patients were studied sequentially, four before and after transcranial bypass surgery. No arterial or tissue delays were found in patients without haemodynamic arterial lesions or cortical infarcts. Seven of nine patients with haemodynamic, extracranial carotid lesions showed ipsilateral delays in arterial or tissue transit times. Tissue delays usually correlated with CT or clinical evidence of infarction. Improved haemodynamics in patients re-studied correlated with the effects of surgery or clinical recovery. DCT has several important limitations but has the potential to provide additional haemodynamic information about the cerebral circulation in selected patients with cerebral arterial occlusive disease. (orig.)

  7. Total and isoform-specific quantitative assessment of circulating Fibulin-1 using selected reaction monitoring mass spectrometry and time-resolved immunofluorometry

    DEFF Research Database (Denmark)

    Overgaard, Martin; Cangemi, Claudia; Jensen, Martin L

    2015-01-01

    biomarker fibulin-1 and its circulating isoforms in human plasma. EXPERIMENTAL DESIGN:: We used bioinformatics analysis to predict total and isoform-specific tryptic peptides for absolute quantitation using SRM-MS. Fibulin-1 was quantitated in plasma by nanoflow-LC-SRM-MS in undepleted plasma and time......PURPOSE:: Targeted proteomics using SRM-MS combined with stable isotope dilution has emerged as a promising quantitative technique for the study of circulating protein biomarkers. The purpose of this study was to develop and characterize robust quantitative assays for the emerging cardiovascular......-resolved immunofluorometric assay (TRIFMA). Both methods were validated and compared to a commercial ELISA (CircuLex). Molecular size determination was performed under native conditions by SEC analysis coupled to SRM-MS and TRIFMA. RESULTS:: Absolute quantitation of total fibulin-1, isoforms -1C and -1D was performed by SRM...

  8. Influence of various forcings on global climate in historical times using a coupled atmosphere-ocean general circulation model

    DEFF Research Database (Denmark)

    Stendel, Martin; Mogensen, Irene A.; Christensen, Jens H.

    2006-01-01

    The results of a simulation of the climate of the last five centuries with a state-of-the-art coupled atmosphere-ocean general circulation model are presented. The model has been driven with most relevant forcings, both natural (solar variability, volcanic aerosol) and anthropogenic (greenhouse...... gases, sulphate aerosol, land-use changes). In contrast to previous GCM studies, we have taken into account the latitudinal dependence of volcanic aerosol and the changing land cover for a period covering several centuries. We find a clear signature of large volcanic eruptions in the simulated...

  9. Continuous real-time in vivo measurement of cerebral nitric oxide supports theoretical predictions of an irreversible switching in cerebral ROS after sufficient exposure to external toxins.

    Science.gov (United States)

    Finnerty, Niall J; O'Riordan, Saidhbhe L; Lowry, John P; Cloutier, Mathieu; Wellstead, Peter

    2013-01-01

    Mathematical models of the interactions between alphasynuclein (αS) and reactive oxygen species (ROS) predict a systematic and irreversible switching to damagingly high levels of ROS after sufficient exposure to risk factors associated with Parkinson's disease (PD). We tested this prediction by continuously monitoring real-time changes in neurochemical levels over periods of several days in animals exposed to a toxin known to cause Parkinsonian symptoms. Nitric oxide (NO) sensors were implanted in the brains of freely moving rats and the NO levels continuously recorded while the animals were exposed to paraquat (PQ) injections of various amounts and frequencies. Long-term, real-time measurement of NO in a cohort of animals showed systematic switching in levels when PQ injections of sufficient size and frequency were administered. The experimental observations of changes in NO imply a corresponding switching in endogenous ROS levels and support theoretical predictions of an irreversible change to damagingly high levels of endogenous ROS when PD risks are sufficiently large. Our current results only consider one form of PD risk, however, we are sufficiently confident in them to conclude that: (i) continuous long-term measurement of neurochemical dynamics provide a novel way to measure the temporal change and system dynamics which determine Parkinsonian damage, and (ii) the bistable feedback switching predicted by mathematical modelling seems to exist and that a deeper analysis of its characteristics would provide a way of understanding the pathogenic mechanisms that initiate Parkinsonian cell damage.

  10. Unilateral cerebral polymicrogyria with ipsilateral cerebral hemiatrophy

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, Katsumi [Department of Radiology, Kyoto City Hospital, 1-2 Higashi-Takada-cho, Mibu, Nakagyo-ku, 604-8845 Kyoto (Japan); Kanda, Toyoko; Yamori, Yuriko [Department of Pediatric Neurology, St. Joseph Hospital for Handicapped Children, 603-8323 Kyoto (Japan)

    2002-10-01

    We evaluated six children in whom MR imaging showed unilateral cerebral polymicrogyria associated with ipsilateral cerebral atrophy and ipsilateral brain stem atrophy. The aim of this study was to clarify whether this disorder based on neuroimaging constitutes a new homogeneous clinical entity. The subjects were six children whose ages at the time of MR imaging ranged from 8 months to 11 years. Their clinical and MR features were analyzed. All of the children were born between 38 and 42 weeks gestation, without any significant perinatal events. Spastic hemiplegia and epilepsy were observed in all of the patients, and mental retardation was observed in four. The MR findings included unilateral cerebral polymicrogyria associated with ipsilateral cerebral hemiatrophy and ipsilateral brain stem atrophy in all patients. The ipsilateral sylvian fissure was hypoplastic in four patients. These patients showed relatively homogeneous clinical and neuroimaging features. Although the additional clinical features varied according to the site and the extent affected by the polymicrogyria, this disorder could constitute a new relatively homogeneous clinical entity. (orig.)

  11. Unilateral cerebral polymicrogyria with ipsilateral cerebral hemiatrophy

    International Nuclear Information System (INIS)

    Hayakawa, Katsumi; Kanda, Toyoko; Yamori, Yuriko

    2002-01-01

    We evaluated six children in whom MR imaging showed unilateral cerebral polymicrogyria associated with ipsilateral cerebral atrophy and ipsilateral brain stem atrophy. The aim of this study was to clarify whether this disorder based on neuroimaging constitutes a new homogeneous clinical entity. The subjects were six children whose ages at the time of MR imaging ranged from 8 months to 11 years. Their clinical and MR features were analyzed. All of the children were born between 38 and 42 weeks gestation, without any significant perinatal events. Spastic hemiplegia and epilepsy were observed in all of the patients, and mental retardation was observed in four. The MR findings included unilateral cerebral polymicrogyria associated with ipsilateral cerebral hemiatrophy and ipsilateral brain stem atrophy in all patients. The ipsilateral sylvian fissure was hypoplastic in four patients. These patients showed relatively homogeneous clinical and neuroimaging features. Although the additional clinical features varied according to the site and the extent affected by the polymicrogyria, this disorder could constitute a new relatively homogeneous clinical entity. (orig.)

  12. Imaging of the appearance time of cerebral blood using [15O]H2O PET for the computation of correct CBF.

    Science.gov (United States)

    Kudomi, Nobuyuki; Maeda, Yukito; Sasakawa, Yasuhiro; Monden, Toshihide; Yamamoto, Yuka; Kawai, Nobuyuki; Iida, Hidehiro; Nishiyama, Yoshihiro

    2013-05-23

    Quantification of cerebral blood flow (CBF) is important for the understanding of normal and pathologic brain physiology. Positron emission tomography (PET) with H215O (or C15O2) can quantify CBF and apply kinetic analyses, including autoradiography (ARG) and the basis function methods (BFM). These approaches, however, are sensitive to input function errors such as the appearance time of cerebral blood (ATB), known as the delay time. We estimated brain ATB in an image-based fashion to correct CBF by accounting for differences in computed CBF values using three different analyses: ARG and BFM with and without fixing the partition coefficient. Subject groups included those with no significant disorders, those with elevated cerebral blood volume, and those with reduced CBF. All subjects underwent PET examination, and CBF was estimated using the three analyses. The ATB was then computed from the differences of the obtained CBF values, and ATB-corrected CBF values were computed. ATB was also estimated for regions of interest (ROIs) of multiple cortical regions. The feasibility of the present method was tested in a simulation study. There were no significant differences in the obtained ATB between the image- and ROI-based methods. Significantly later appearance was found in the cerebellum compared to other brain regions for all groups. In cortical regions where CBF was reduced due to occlusive lesions, the ATB was 0.2 ± 1.2 s, which was significantly delayed relative to the contralateral regions. A simulation study showed that the ATB-corrected CBF was less sensitive to errors in input function, and noise on the tissue curve did not enhance the degree of noise on ATB-corrected CBF image. This study demonstrates the potential utility of visualizing the ATB in the brain, enabling the determination of CBF with less sensitivity to error in input function.

  13. Cerebral oximetry in preterm infants

    DEFF Research Database (Denmark)

    Greisen, Gorm; Andresen, Bjørn; Plomgaard, Anne Mette

    2016-01-01

    Preterm birth constitutes a major cause of death before 5 years of age and it is a major cause of neurodevelopmental impairment across the world. Preterm infants are most unstable during the transition between fetal and newborn life during the first days of life and most brain damage occurs...... in this period. The brain of the preterm infant is accessible for tissue oximetry by near-infrared spectroscopy. Cerebral oximetry has the potential to improve the long-term outcome by helping to tailor the support of respiration and circulation to the individual infant's needs, but the evidence is still lacking....... The goals for research include testing the benefit and harms of cerebral oximetry in large-scale randomized trials, improved definition of the hypoxic threshold, better understanding the effects of intensive care on cerebral oxygenation, as well as improved precision of oximeters and calibration among...

  14. Dynamic CT in early stage of cerebral ischemia; Clinical usefulness of dynamic CT for rapid evaluation of patients considered for emergency cerebral revascularization

    Energy Technology Data Exchange (ETDEWEB)

    Aritake, Koichi; Sano, Keiji (Fuji Brain Inst. Hospital, Fujinomiya, Shizuoka (Japan))

    1990-12-01

    In the present study, we correlated collateral flow patterns derived from dynamic CT (DCT) and the evolution of cerebral infarction in patients with ischemic episodes and analyzed the efficacy of emergency cerebral revascularization (ECR) in preventing infarction. Forty-four patients, all of whom presented cerebral arterial occlusion without showing any hypodense areas on their initial CT scans, were examined. Eleven patients underwent ECR. Time-density curves (TDCs) within 239 different regions in territories of occluded arteries were derived from DCT. The degree of collateral flow and delay of circulation time were assessed, comparing peak values and peak times of TDCs on the occluded side with those in corresponding regions on the non-occluded side. Hemodynamic patterns of TDCs were classified into the following three types: Type 1 - the residual flow was considerably preserved with markedly delayed circulation time; Type 2 - the collateral flow was considerably preserved, but its circulation time was minimally or moderately delayed; and Type 3 - the residual flow was minimal or moderate with or without slowing of circulation time. In the medically-treated group, follow-up CT scans demonstrated infarction in 89% of Type 1, 6% of Type 2 and 97% of Type 3. In the surgically-treated group, infarction developed in 20% of Type 1, 0% of Type 2 and 95% of Type 3. The hemodynamic pattern map, demonstrated with the advent of the personal computer, was clinically useful in predicting the appearance and extent of infarction and judging the prognosis of patients, even immediately after the ischemic ictus. It would appear that patients whose preoperative DCT discloses a Type 1 perfusion pattern can be expected to benefit the most from ECR. (author).

  15. Time-dependent correlation of cerebral blood flow with oxygen metabolism in activated human visual cortex as measured by fMRI.

    Science.gov (United States)

    Lin, Ai-Ling; Fox, Peter T; Yang, Yihong; Lu, Hanzhang; Tan, Li-Hai; Gao, Jia-Hong

    2009-01-01

    The aim of this study was to investigate the relationship between relative cerebral blood flow (delta CBF) and relative cerebral metabolic rate of oxygen (delta CMRO(2)) during continuous visual stimulation (21 min at 8 Hz) with fMRI biophysical models by simultaneously measuring of BOLD, CBF and CBV fMRI signals. The delta CMRO(2) was determined by both a newly calibrated single-compartment model (SCM) and a multi-compartment model (MCM) and was in agreement between these two models (P>0.5). The duration-varying delta CBF and delta CMRO(2) showed a negative correlation with time (r=-0.97, PSCM, an incorrect and even an opposite appearance of the flow-metabolism relationship during prolonged visual stimulation (positively linear coupling) can result. The time-dependent negative correlation between flow and metabolism demonstrated in this fMRI study is consistent with a previous PET observation and further supports the view that the increase in CBF is driven by factors other than oxygen demand and the energy demands will eventually require increased aerobic metabolism as stimulation continues.

  16. Experimental Focal Cerebral Ischemia

    DEFF Research Database (Denmark)

    Christensen, Thomas

    2007-01-01

    Focal cerebral ischemia due to occlusion of a major cerebral artery is the cause of ischemic stroke which is a major reason of mortality, morbidity and disability in the populations of the developed countries. In the seven studies summarized in the thesis focal ischemia in rats induced by occlusion...... in the penumbra is recruited in the infarction process leading to a progressive growth of the infarct. The penumbra hence constitutes an important target for pharmacological treatment because of the existence of a therapeutic time window during which treatment with neuroprotective compounds may prevent...

  17. Cerebral blood volume changes in cats with acute increased intracranial pressure

    International Nuclear Information System (INIS)

    Kondo, Takashi; Kano, Mitsumasa; Ikeda, Takuya.

    1984-01-01

    We measured the changes in cerebral blood volume in cats with increased intracranial pressure with a high-speed CT scanner, employing contrast effects by the iodine agent. In acute increased intracranial pressure caused by raising the extradural pressure by 20 mmHg, cerebral blood volume showed a significant decrease by 32% in comparison with that at normal intracranial pressure. There was also a tendency that a decline of iodine was delayed with time at increased intracranial pressure than that at normal pressure. This was supposed to be a delay of cerebral circulation due to venous congestion. This experimental model and measuring method provide the changes in CBV in the same individual without any tedious procedure, and therefore this is a reliable method with respect to precision. (author)

  18. Concept and laboratory experiments for a new lost circulation material pulser (LCM-Pulser) for real time data transmission in boreholes

    Energy Technology Data Exchange (ETDEWEB)

    Namuq, M.A.; Reich, M.; Kirsten, U.; Sohmer, M.; Lehmann, F. [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Bohrtechnik und Fluidbergbau; Mueller, T. [Adensis GmbH, Dresden (Germany)

    2013-08-01

    It would not be possible to drill through the planned paths to reach targets and optimize the drilling process while drilling without transmitting the geological and directional information to the surface. The most commonly used method for transmitting data is by coded pressure pulses (known as mud pulse telemetry), which propagate to the surface, where they are detected, decoded and displayed for making real time decisions. Mud pulse telemetry systems are using positive, negative or continuous wave pulsers. Mud pulsers are the most critical components of the bottom-hole-assembly with regards to plugging by lost circulation materials. Therefore increasing the tolerance of mud pulse telemetry systems for lost circulation material applications is desired. The plugging of the pulser by lost circulation materials leads to blind drilling, thereby necessitating a trip out of the borehole, consequently increasing the costs of the well. Moreover, one of the contributors to downhole tool failures is the mechanical components associated with mud pulse telemetry. The damage of those components leads to the same previously mentioned problems. All available mud pulse telemetry systems can only generate higher pressure pulse amplitudes by further restricting the flow area. This is necessary in deep wells, where pressure pulses are significantly attenuated on their way to the surface, but leads also to further restrictions when using lost circulation materials. The concept for developing an innovative pulser (named LCM-pulser) and a brief introduction to the experimental setup for evaluating the performance of the pulser will be presented in this paper. The LCM-pulser prototype has been constructed and series of initial experiments have been carried out. The test facilities consist of a flow loop with a pipe line, the new LCM-pulser and a pressure sensor. The fluid used in the experiments is water. With this novel pulser, it is not necessary to restrict the flow area anymore, so

  19. Development and evaluation of tailored specific real-time RT-PCR assays for detection of foot-and-mouth disease virus serotypes circulating in East Africa.

    Science.gov (United States)

    Bachanek-Bankowska, Katarzyna; Mero, Herieth R; Wadsworth, Jemma; Mioulet, Valerie; Sallu, Raphael; Belsham, Graham J; Kasanga, Christopher J; Knowles, Nick J; King, Donald P

    2016-11-01

    Rapid, reliable and accurate diagnostic methods provide essential support to programmes that monitor and control foot-and-mouth disease (FMD). While pan-specific molecular tests for FMD virus (FMDV) detection are well established and widely used in endemic and FMD-free countries, current serotyping methods mainly rely either on antigen detection ELISAs or nucleotide sequencing approaches. This report describes the development of a panel of serotype-specific real-time RT-PCR assays (rRT-PCR) tailored to detect FMDV lineages currently circulating in East Africa. These assays target sequences within the VP1-coding region that share high intra-lineage identity, but do not cross-react with FMD viruses from other serotypes that circulate in the region. These serotype-specific assays operate with the same thermal profile as the pan-diagnostic tests making it possible to run them in parallel to produce C T values comparable to the pan-diagnostic test detecting the 3D-coding region. These assays were evaluated alongside the established pan-specific molecular test using field samples and virus isolates collected from Tanzania, Kenya and Ethiopia that had been previously characterised by nucleotide sequencing. Samples (n=71) representing serotype A (topotype AFRICA, lineage G-I), serotype O (topotypes EA-2 and EA-4), serotype SAT 1 (topotype I (NWZ)) and serotype SAT2 (topotype IV) were correctly identified with these rRT-PCR assays. Furthermore, FMDV RNA from samples that did not contain infectious virus could still be serotyped using these assays. These serotype-specific real-time RT-PCR assays can detect and characterise FMDVs currently circulating in East Africa and hence improve disease control in this region. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  20. 3D CT cerebral angiography technique using a 320-detector machine with a time–density curve and low contrast medium volume: Comparison with fixed time delay technique

    International Nuclear Information System (INIS)

    Das, K.; Biswas, S.; Roughley, S.; Bhojak, M.; Niven, S.

    2014-01-01

    Aim: To describe a cerebral computed tomography angiography (CTA) technique using a 320-detector CT machine and a small contrast medium volume (35 ml, 15 ml for test bolus). Also, to compare the quality of these images with that of the images acquired using a larger contrast medium volume (90 or 120 ml) and a fixed time delay (FTD) of 18 s using a 16-detector CT machine. Materials and methods: Cerebral CTA images were acquired using a 320-detector machine by synchronizing the scanning time with the time of peak enhancement as determined from the time–density curve (TDC) using a test bolus dose. The quality of CTA images acquired using this technique was compared with that obtained using a FTD of 18 s (by 16-detector CT), retrospectively. Average densities in four different intracranial arteries, overall opacification of arteries, and the degree of venous contamination were graded and compared. Results: Thirty-eight patients were scanned using the TDC technique and 40 patients using the FTD technique. The arterial densities achieved by the TDC technique were higher (significant for supraclinoid and basilar arteries, p < 0.05). The proportion of images deemed as having “good” arterial opacification was 95% for TDC and 90% for FTD. The degree of venous contamination was significantly higher in images produced by the FTD technique (p < 0.001%). Conclusion: Good diagnostic quality CTA images with significant reduction of venous contamination can be achieved with a low contrast medium dose using a 320-detector machine by coupling the time of data acquisition with the time of peak enhancement

  1. Cerebral time domain-NIRS: reproducibility analysis, optical properties, hemoglobin species and tissue oxygen saturation in a cohort of adult subjects.

    Science.gov (United States)

    Giacalone, Giacomo; Zanoletti, Marta; Contini, Davide; Re, Rebecca; Spinelli, Lorenzo; Roveri, Luisa; Torricelli, Alessandro

    2017-11-01

    The reproducibility of cerebral time-domain near-infrared spectroscopy (TD-NIRS) has not been investigated so far. Besides, reference intervals of cerebral optical properties, of absolute concentrations of deoxygenated-hemoglobin (HbR), oxygenated-hemoglobin (HbO), total hemoglobin (HbT) and tissue oxygen saturation (StO 2 ) and their variability have not been reported. We have addressed these issues on a sample of 88 adult healthy subjects. TD-NIRS measurements at 690, 785, 830 nm were fitted with the diffusion model for semi-infinite homogenous media. Reproducibility, performed on 3 measurements at 5 minutes intervals, ranges from 1.8 to 6.9% for each of the hemoglobin species. The mean ± SD global values of HbR, HbO, HbT, StO 2 are respectively 24 ± 7 μM, 33.3 ± 9.5 μM, 57.4 ± 15.8 μM, 58 ± 4.2%. StO 2 displays the narrowest range of variability across brain regions.

  2. The study of 1H-MRS on monkey of resuscitation after cerebral selection ultra-profound hypothermic blood flow occlusion

    International Nuclear Information System (INIS)

    Pu Jun; Xu Wei; Fang Shaolong; Zhao Xinxiang; Feng Zhongtang; Jiang Jiyao

    2005-01-01

    Objective: To investigate the appearance and feature of 1 H/protion magnetic resonance spectroscopy ( 1 H-MRS) on resuscitation after cerebral selective ultra-profound hypothermic and blood flow occlusion. To study effects of cerebral biochemical metabolism after cerebral selective ultra-profound hypothermia and blood flow occlusion and to explore the validity and feasibility of it. Methods: Bilateral carotid arteries and jugular veins were clipped about 10 minutes before perfusion. Then selective cerebral circulation was established by perfusion of cooling lingers liquid through right internal carotid artery and flow out of left jugular vein with clip of other carotid arteries and jugular veins. Brain temperature reached (15.1 ± 0.9) degree C, while the body temperature maintained (32.50 ± 0.58) degree C. Cerebral blood recovered after 60 minutes of cerebral ischemia and monkey came back. The cerebral MAI and DWI as well as 1 H-MRS were examined 4, 24, 72 h, 21 days before and after cerebral selective ultro-profound hypothermia and blood flow occlusion. The peak of N-acetyl-aspartate (NAA), Choline (Cho), creatine and phosphocreatine (Cr, PCr) of VOL were compare with those of control group in different time. Results: MRI T 1 WI, MRI T 2 WI and DWI is normal in different time in different region; there was not a significant difference in the ratio of NAA/(Cr+PCr), Cho/(Cr+PCr) in ROI in different time in the different region in the light of statistical analysis (P>0.05). Conclusion: The light of cerebral biochemical metabolism, selective ultra-profound hypothermia is safety and may provide effective protective effects and safety during cerebral ischemia. (authors)

  3. SU-G-IeP1-12: Size Selective Arterial Cerebral Blood Volume Mapping Using Multiple Inversion Time Arterial Spin Labeling

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Y; Johnston, M; Whitlow, C [Wake Forest School of Medicine, Winston-salem, NC (United States); Liu, H [UT MD Anderson Cancer Center, Houston, TX (United States)

    2016-06-15

    Purpose: To demonstrate the feasibility of a novel method for size specific arterial cerebral blood volume (aCBV) mapping using pseudo-continuous arterial spin labeling (PCASL), with multiple TI. Methods: Multiple PCASL images were obtained from a subject with TI of [300, 400, 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 3500, 4000] ms. Each TI pair was averaged six times. Two scans were performed: one without a flow crusher gradient and the other with a crusher gradient (10cm/s in three directions) to remove signals from large arteries. Scan times were 5min. without a crusher gradient and 5.5 min with a crusher gradient. Non-linear fitting algorithm finds the minimum mean squared solution of per-voxel based aCBV, cerebral blood flow, and arterial transit time, and fits the data into a hemodynamic model that represents superposition of blood volume and flow components within a single voxel. Results: aCBV maps with a crusher gradient represent signals from medium and small sized arteries, while those without a crusher gradient represent signals from all sized arteries, indicating that flow crusher gradients can be effectively employed to achieve size-specific aCBV mapping. Regardless of flow crusher, the CBF and ATT maps are very similar in appearance. Conclusion: Quantitative size selective blood volume mapping controlled by a flow crusher is feasible without additional information because the ASL quantification process doesn’t require an arterial input function measured from a large artery. The size specific blood volume mapping is not interfered by sSignals from large arteries do not interfere with size specific aCBV mapping in the applications of interest in for applications in which only medium or small arteries are of interest.

  4. Estimation of arterial arrival time and cerebral blood flow from QUASAR arterial spin labeling using stable spline.

    Science.gov (United States)

    Castellaro, Marco; Peruzzo, Denis; Mehndiratta, Amit; Pillonetto, Gianluigi; Petersen, Esben Thade; Golay, Xavier; Chappell, Michael A; Bertoldo, Alessandra

    2015-12-01

    QUASAR arterial spin labeling (ASL) permits the application of deconvolution approaches for the absolute quantification of cerebral perfusion. Currently, oscillation index regularized singular value decomposition (oSVD) combined with edge-detection (ED) is the most commonly used method. Its major drawbacks are nonphysiological oscillations in the impulse response function and underestimation of perfusion. The aim of this work is to introduce a novel method to overcome these limitations. A system identification method, stable spline (SS), was extended to address ASL peculiarities such as the delay in arrival of the arterial blood in the tissue. The proposed framework was compared with oSVD + ED in both simulated and real data. SS was used to investigate the validity of using a voxel-wise tissue T1 value instead of using a single global value (of blood T1 ). SS outperformed oSVD + ED in 79.9% of simulations. When applied to real data, SS exhibited a physiologically realistic range for perfusion and a higher mean value with respect to oSVD + ED (55.5 ± 9.5 SS, 34.9 ± 5.2 oSVD + ED mL/100 g/min). SS can represent an alternative to oSVD + ED for the quantification of QUASAR ASL data. Analysis of the retrieved impulse response function revealed that using a voxel wise tissue T1 might be suboptimal. © 2014 Wiley Periodicals, Inc.

  5. A recommended workflow methodology in the creation of an educational and training application incorporating a digital reconstruction of the cerebral ventricular system and cerebrospinal fluid circulation to aid anatomical understanding.

    Science.gov (United States)

    Manson, Amy; Poyade, Matthieu; Rea, Paul

    2015-10-19

    The use of computer-aided learning in education can be advantageous, especially when interactive three-dimensional (3D) models are used to aid learning of complex 3D structures. The anatomy of the ventricular system of the brain is difficult to fully understand as it is seldom seen in 3D, as is the flow of cerebrospinal fluid (CSF). This article outlines a workflow for the creation of an interactive training tool for the cerebral ventricular system, an educationally challenging area of anatomy. This outline is based on the use of widely available computer software packages. Using MR images of the cerebral ventricular system and several widely available commercial and free software packages, the techniques of 3D modelling, texturing, sculpting, image editing and animations were combined to create a workflow in the creation of an interactive educational and training tool. This was focussed on cerebral ventricular system anatomy, and the flow of cerebrospinal fluid. We have successfully created a robust methodology by using key software packages in the creation of an interactive education and training tool. This has resulted in an application being developed which details the anatomy of the ventricular system, and flow of cerebrospinal fluid using an anatomically accurate 3D model. In addition to this, our established workflow pattern presented here also shows how tutorials, animations and self-assessment tools can also be embedded into the training application. Through our creation of an established workflow in the generation of educational and training material for demonstrating cerebral ventricular anatomy and flow of cerebrospinal fluid, it has enormous potential to be adopted into student training in this field. With the digital age advancing rapidly, this has the potential to be used as an innovative tool alongside other methodologies for the training of future healthcare practitioners and scientists. This workflow could be used in the creation of other tools

  6. Symptomatic middle cerebral artery stenosis and occlusion. Comparison of three-dimensional time-of-flight magnetic resonance angiography with conventional angiography

    Energy Technology Data Exchange (ETDEWEB)

    Sawada, Motoshi; Yano, Hirohito; Shinoda, Jun; Funakoshi, Takashi [Daiyukai General Hospital, Ichinomiya, Aichi (Japan); Kumagai, Morio

    1994-10-01

    The usefulness of magnetic resonance (MR) angiography using the three-dimensional time-of-flight method for the characterization of symptomatic middle cerebral artery (MCA) occlusive lesions was evaluated in 10 patients with MCA occlusion and 10 with MCA stenosis. All lesions were symptomatic and documented by conventional angiography. There was no false-negative MR angiogram that failed to demonstrate the MCA occlusive lesion. MR angiography correctly evaluated the location of lesions and the difference between stenosis and occlusion. Stenosis appeared as a focal signal loss (<1.0cm) of the MCA at the site of stenosis, and occlusion as a complete signal loss of the MCA distal to the site of occlusion. However, MR angiography could not distinguish diffuse stenosis and one point stenosis demonstrated by conventional angiography. MR angiography is a useful noninvasive diagnostic method for evaluating occlusive lesions of the MCA in symptomatic patients. (author).

  7. Circulation of different lineages of dengue virus type 2 in Central America, their evolutionary time-scale and selection pressure analysis.

    Directory of Open Access Journals (Sweden)

    Germán Añez

    Full Text Available Dengue is caused by any of the four serotypes of dengue virus (DENV-1 to 4. Each serotype is genetically distant from the others, and each has been subdivided into different genotypes based on phylogenetic analysis. The study of dengue evolution in endemic regions is important since the diagnosis is often made by nucleic acid amplification tests, which depends upon recognition of the viral genome target, and natural occurring mutations can affect the performance of these assays. Here we report for the first time a detailed study of the phylogenetic relationships of DENV-2 from Central America, and report the first fully sequenced DENV-2 strain from Guatemala. Our analysis of the envelope (E protein and of the open reading frame of strains from Central American countries, between 1999 and 2009, revealed that at least two lineages of the American/Asian genotype of DENV-2 have recently circulated in that region. In occasions the co-circulation of these lineages may have occurred and that has been suggested to play a role in the observed increased severity of clinical cases. Our time-scale analysis indicated that the most recent common ancestor for Central American DENV-2 of the American/Asian genotype existed about 19 years ago. Finally, we report positive selection in DENV-2 from Central America in codons of the genes encoding for C, E, NS2A, NS3, and NS5 proteins. Some of these identified codons are novel findings, described for the first time for any of the DENV-2 genotypes.

  8. United Cerebral Palsy

    Science.gov (United States)

    ... your local affiliate Find your local affiliate United Cerebral Palsy United Cerebral Palsy (UCP) is a trusted resource for individuals with Cerebral Palsy and other disabilities and their networks. Individuals with ...

  9. Employees with Cerebral Palsy

    Science.gov (United States)

    ... Resources Home | Accommodation and Compliance Series: Employees with Cerebral Palsy (CP) By Eddie Whidden, MA Preface Introduction Information ... SOAR) at http://AskJAN.org/soar. Information about Cerebral Palsy (CP) What is CP? Cerebral palsy is a ...

  10. Birth Defects: Cerebral Palsy

    Science.gov (United States)

    ... Loss > Birth defects & other health conditions > Cerebral palsy Cerebral palsy E-mail to a friend Please fill in ... this page It's been added to your dashboard . Cerebral palsy (also called CP) is a group of conditions ...

  11. Development and evaluation of tailored specific real-time RT-PCR assays for detection of foot-and-mouth disease virus serotypes circulating in East Africa

    DEFF Research Database (Denmark)

    Bachanek-Bankowska, Katarzyna; Mero, Herieth R.; Wadsworth, Jemma

    2016-01-01

    Rapid, reliable and accurate diagnostic methods provide essential support to programmes that monitor and control foot-and-mouth disease (FMD). While pan-specific molecular tests for FMD virus (FMDV) detection are well established and widely used in endemic and FMD-free countries, current serotyping...... methods mainly rely either on antigen detection ELISAs or nucleotide sequencing approaches. This report describes the development of a panel of serotype-specific real-time RT-PCR assays (rRT-PCR) tailored to detect FMDV lineages currently circulating in East Africa. These assays target sequences within...... sequencing. Samples (n = 71) representing serotype A (topotype AFRICA, lineage G-I), serotype O (topotypes EA-2 and EA-4), serotype SAT 1 (topotype I (NWZ)) and serotype SAT2 (topotype IV) were correctly identified with these rRT-PCR assays. Furthermore, FMDV RNA from samples that did not contain infectious...

  12. The effects of capillary transit time heterogeneity (CTH on the cerebral uptake of glucose and glucose analogs:Application to FDG and comparison to oxygen uptake.

    Directory of Open Access Journals (Sweden)

    Hugo Angleys

    2016-10-01

    Full Text Available Glucose is the brain’s principal source of ATP, but the extent to which cerebral glucose consumption (CMRglc is coupled with its oxygen consumption (CMRO2 remains unclear. Measurements of the brain’s oxygen-glucose index OGI=CMRO2/CMRglc suggest that its oxygen uptake largely suffices for oxidative phosphorylation. Nevertheless, during functional activation and in some disease states, brain tissue seemingly produces lactate although cerebral blood flow (CBF delivers sufficient oxygen, so-called aerobic glycolysis. OGI measurements, in turn, are method-dependent in that estimates based on glucose analog uptake depend on the so-called lumped constant (LC to arrive at CMRglc. Capillary transit time heterogeneity (CTH, which is believed to change during functional activation and some disease states, affects the extraction efficacy of oxygen from blood. We developed a three-compartment model of glucose extraction to examine whether CTH also affects glucose extraction into brain tissue. We then combined this model with our previous model of oxygen extraction to examine whether differential glucose and oxygen extraction might favor nonoxidative glucose metabolism under certain conditions. Our model predicts that glucose uptake is largely unaffected by changes in its plasma concentration, while changes in CBF and CTH affect glucose and oxygen uptake to different extents. Accordingly, functional hyperemia facilitates glucose uptake more than oxygen uptake, favoring aerobic glycolysis during enhanced energy demands. Applying our model to glucose analogs, we observe that LC depends on physiological state, with a risk of overestimating relative increases in CMRglc during functional activation by as much as 50%.

  13. Improved cerebral time-of-flight magnetic resonance angiography at 7 Tesla--feasibility study and preliminary results using optimized venous saturation pulses.

    Directory of Open Access Journals (Sweden)

    Karsten H Wrede

    Full Text Available PURPOSE: Conventional saturation pulses cannot be used for 7 Tesla ultra-high-resolution time-of-flight magnetic resonance angiography (TOF MRA due to specific absorption rate (SAR limitations. We overcome these limitations by utilizing low flip angle, variable rate selective excitation (VERSE algorithm saturation pulses. MATERIAL AND METHODS: Twenty-five neurosurgical patients (male n = 8, female n = 17; average age 49.64 years; range 26-70 years with different intracranial vascular pathologies were enrolled in this trial. All patients were examined with a 7 Tesla (Magnetom 7 T, Siemens whole body scanner system utilizing a dedicated 32-channel head coil. For venous saturation pulses a 35° flip angle was applied. Two neuroradiologists evaluated the delineation of arterial vessels in the Circle of Willis, delineation of vascular pathologies, presence of artifacts, vessel-tissue contrast and overall image quality of TOF MRA scans in consensus on a five-point scale. Normalized signal intensities in the confluence of venous sinuses, M1 segment of left middle cerebral artery and adjacent gray matter were measured and vessel-tissue contrasts were calculated. RESULTS: Ratings for the majority of patients ranged between good and excellent for most of the evaluated features. Venous saturation was sufficient for all cases with minor artifacts in arteriovenous malformations and arteriovenous fistulas. Quantitative signal intensity measurements showed high vessel-tissue contrast for confluence of venous sinuses, M1 segment of left middle cerebral artery and adjacent gray matter. CONCLUSION: The use of novel low flip angle VERSE algorithm pulses for saturation of venous vessels can overcome SAR limitations in 7 Tesla ultra-high-resolution TOF MRA. Our protocol is suitable for clinical application with excellent image quality for delineation of various intracranial vascular pathologies.

  14. Improved Cerebral Time-of-Flight Magnetic Resonance Angiography at 7 Tesla – Feasibility Study and Preliminary Results Using Optimized Venous Saturation Pulses

    Science.gov (United States)

    Wrede, Karsten H.; Johst, Sören; Dammann, Philipp; Özkan, Neriman; Mönninghoff, Christoph; Kraemer, Markus; Maderwald, Stefan; Ladd, Mark E.; Sure, Ulrich; Umutlu, Lale; Schlamann, Marc

    2014-01-01

    Purpose Conventional saturation pulses cannot be used for 7 Tesla ultra-high-resolution time-of-flight magnetic resonance angiography (TOF MRA) due to specific absorption rate (SAR) limitations. We overcome these limitations by utilizing low flip angle, variable rate selective excitation (VERSE) algorithm saturation pulses. Material and Methods Twenty-five neurosurgical patients (male n = 8, female n = 17; average age 49.64 years; range 26–70 years) with different intracranial vascular pathologies were enrolled in this trial. All patients were examined with a 7 Tesla (Magnetom 7 T, Siemens) whole body scanner system utilizing a dedicated 32-channel head coil. For venous saturation pulses a 35° flip angle was applied. Two neuroradiologists evaluated the delineation of arterial vessels in the Circle of Willis, delineation of vascular pathologies, presence of artifacts, vessel-tissue contrast and overall image quality of TOF MRA scans in consensus on a five-point scale. Normalized signal intensities in the confluence of venous sinuses, M1 segment of left middle cerebral artery and adjacent gray matter were measured and vessel-tissue contrasts were calculated. Results Ratings for the majority of patients ranged between good and excellent for most of the evaluated features. Venous saturation was sufficient for all cases with minor artifacts in arteriovenous malformations and arteriovenous fistulas. Quantitative signal intensity measurements showed high vessel-tissue contrast for confluence of venous sinuses, M1 segment of left middle cerebral artery and adjacent gray matter. Conclusion The use of novel low flip angle VERSE algorithm pulses for saturation of venous vessels can overcome SAR limitations in 7 Tesla ultra-high-resolution TOF MRA. Our protocol is suitable for clinical application with excellent image quality for delineation of various intracranial vascular pathologies. PMID:25232868

  15. Recurrent cerebral thrombosis

    International Nuclear Information System (INIS)

    Iwamoto, Toshihiko; Abe, Shin-e; Kubo, Hideki; Hanyu, Haruo; Takasaki, Masaru

    1992-01-01

    Neuroradiological techniques were used to elucidate pathophysiology of recurrent cerebral thrombosis. Twenty-two patients with cerebral thrombosis who suffered a second attack under stable conditions more than 22 days after the initial stroke were studied. Hypertension, diabetes mellitus, and hypercholesterolemia were also seen in 20, 8, and 12 patients, respectively. The patients were divided into three groups according to their symptoms: (I) symptoms differed between the first and second strokes (n=12); (II) initial symptoms were suddenly deteriorated (n=6); and (III) symptoms occurring in groups I and II were seen (n=4). In group I, contralateral hemiparesis or suprabulbar palsy was often associated with the initial hemiparesis. The time of recurrent stroke varied from 4 months to 9 years. CT and MRI showed not only lacunae in both hemispheres, but also deep white-matter ischemia of the centrum semi-ovale. In group II, hemiparesis or visual field defect was deteriorated early after the initial stroke. In addition, neuroimaging revealed that infarction in the posterior cerebral artery was progressed on the contralateral side, or that white matter lesion in the middle artery was enlarged in spite of small lesion in the left cerebral hemisphere. All patients in group III had deterioration of right hemiparesis associated with aphasia. CT, MRI, SPECT, and angiography indicated deep white-matter ischemia caused by main trunk lesions in the left hemisphere. Group III seemed to be equivalent to group II, except for laterality of the lesion. Neuroradiological assessment of the initial stroke may help to predict the mode of recurrence, although pathophysiology of cerebral thrombosis is complicated and varies from patient to patient. (N.K.)

  16. Cerebral palsy

    International Nuclear Information System (INIS)

    Truwit, C.L.; Barkovich, A.J.; Koch, T.; Ferreiro, D.

    1990-01-01

    This paper reviews cranial MR findings in patients with cerebral palsy (CP) to clarify and categorize this disorder. The MR images of 40 patients with clinical CP were retrospectively reviewed. All patients suffered either varying spastic plegias, hypotonicity, or choreoathetosis. Concomitantly, the patients suffered from static encephalopathy, developmental delay, and/or microcephaly. Twenty-four patients were born at or near term, 10 were premature, and incomplete birth histories were available in six. The MR images revealed mild to severe degrees of white matter damage in 24 patients (12 term, nine premature, three unknown)

  17. Effect of PPARγ Inhibition during Pregnancy on Posterior Cerebral Artery Function and Structure

    Directory of Open Access Journals (Sweden)

    Siu-Lung eChan

    2010-08-01

    Full Text Available Peroxisome proliferator-activated receptor-γ (PPARγ, a ligand-activated transcription factor, has protective roles in the cerebral circulation, and, is highly activated during pregnancy. Thus, we hypothesized that PPARγ is involved in the adaptation of cerebral vasculature to pregnancy. Nonpregnant (NP and late-pregnant (LP rats were treated with a specific PPARγ inhibitor GW9662 (10 mg/kg/day, in food or vehicle for 10 days and vascular function and structural remodeling were determined in isolated and pressurized posterior cerebral arteries (PCA. Expression of PPARγ and angiotensin type 1 receptor (AT1R in cerebral (pial vessels was determined by real-time RT-PCR. PPARγ inhibition decreased blood pressure and increased blood glucose in NP rats, but not in LP rats. PPARγ inhibition reduced dilation to acetylcholine and sodium nitroprusside in PCA from NP (p<0.05 vs. LP-GW, but not LP rats. PPARγ inhibition tended to increase basal tone and myogenic activity in PCA from NP rats, but not LP rats. Structurally, PPARγ inhibition increased wall-thickness in PCA from both NP and LP rats (p<0.05, but increased distensibility only in PCA from NP rats. Pregnancy decreased expression of PPARγ and AT1R (p<0.05 in cerebral arteries that was not affected by GW9662 treatment. These results suggest that PPARγ inhibition had significant effects on the function and structure of PCA in the NP state, but appeared to have less influence during pregnancy. Down-regulation of PPARγ and AT1R in cerebral arteries may be responsible for the lack of effect of PPARγ in cerebral vasculature and may be part of the vascular adaptation to pregnancy.

  18. Cerebral hemodynamics in adult ischemic-type patients with moyamoya disease compared with those of atherothrombotic middle cerebral artery occlusion

    International Nuclear Information System (INIS)

    Idei, Masaru; Yamane, Kanji; Nishida, Masahiro; Manabe, Kazufumi; Yokota, Akira

    2005-01-01

    We measured regional cerebral blood flow (rCBF) in adult ischemic-type patients with moyamoya disease and in patients with atherothrombotic middle cerebral artery occlusion (MCAO) to investigate cerebral hemodynamics in adult ischemic-type of moyamoya disease. In this study we measured rCBF and regional cerebro-vascular response (rCVR) using acetazolamide by Xe-non-enhanced CT. Our subjects consisted of 15 adult ischemic-type patients with moyamoya disease and 27 atherothrombotic stroke patients with proximal occlusion of the middle cerebral artery. The region of inter est was conducted in the anterior cerebral artery, middle cerebral artery and posterior cerebral artery territories as well as basal ganglia regions. rGBF was preserved in all regions of patients with moyamoya disease. However, rCVR severely decreased in the anterior circulation territory in patients with moyamoya disease compared with those of MCAO. These results suggest that rCBF in the anterior circulation territory of adult ischemic-type patients with moyamoya disease is preserved by vasodilation of the cerebral arteries, while cerebral hemodynamic reserve capacity is severely reduced. The results indicated that basal moyamoya vessels are dilated. These findings may be one of the reasons why stroke occurs more frequently in adult than child patients with moyamoya disease. (author)

  19. Regional Cerebral Oximetry During Cardiopulmonary Resuscitation: Useful or Useless?

    Science.gov (United States)

    Genbrugge, Cornelia; Dens, Jo; Meex, Ingrid; Boer, Willem; Eertmans, Ward; Sabbe, Marc; Jans, Frank; De Deyne, Cathy

    2016-01-01

    Approximately 375,000 people annually experience sudden cardiac arrest (CA) in Europe. Most patients who survive the initial hours and days after CA die of postanoxic brain damage. Current monitors, such as electrocardiography and end-tidal capnography, provide only indirect information about the condition of the brain during cardiopulmonary resuscitation (CPR). In contrast, cerebral near-infrared spectroscopy provides continuous, noninvasive, real-time information about brain oxygenation without the need for a pulsatile blood flow. It measures transcutaneous cerebral tissue oxygen saturation (rSO2). This information could supplement currently used monitors. Moreover, an evolution in rSO2 monitoring technology has made it easier to assess rSO2 in CA conditions. We give an overview of the literature regarding rSO2 measurements during CPR and the current commercially available devices. We highlight the feasibility of cerebral saturation measurement during CPR, its role as a quality parameter of CPR, predictor of return of spontaneous circulation (ROSC) and neurologic outcome, and its monitoring function during transport. rSO2 is feasible in the setting of CA and has the potential to measure the quality of CPR, predict ROSC and neurologic outcome, and monitor post-CA patients during transport. The literature shows that rSO2 has the potential to serve multiple roles as a neuromonitoring tool during CPR and also to guide neuroprotective therapeutic strategies. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Evaluation of time dependency of the acetazolamide effect on cerebral hemodynamics as measured by {sup 99m}Tc-ECD single-photon emission computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Takaki, Akihiro; Urata, Joji; Okada, Kazuhiro; Takaki, Rie [Saiseikai Kumamoto Hospital (Japan). Diagnostic Imaging Center; Mizuta, Yoshihiko; Murakami, Masaji; Yonehara, Toshiroh; Hirano, Teruyuki; Fujioka, Shodo

    2001-01-01

    Kuwabara et al. have examined the cerebral artery dilation with acetazolamide (ACZ) challenge test using PET. And, they reported that ACZ reaction came out time dependently. We have developed a unique SPECT's method using Technetium-99m ethyl cysteinate dimer ({sup 99m}Tc-ECD) to verify the results obtained by Kuwabara et al. One thousand MBq of {sup 99m}Tc-ECD was exactly divided into three syringes. Each of which was intravenous infused (IV) at rest, 7.5, and 20 minutes after ACZ administration. Data collection was started using dynamic SPECT immediately after {sup 99m}Tc-ECD IV at rest. Using necessary data only, SPECT images representing each of the three {sup 99m}Tc-ECD IV was reconstructed. SPECT counts were obtained by the ROI method from each images to calculate relative CBF from rest to 7.5 and 20 minutes after ACZ administration. The 18 hemispheres of nine patients in the negative control group in whom ACZ was not loaded, CBF was stable during the three evaluation. The measurement error our method was estimated as small. The 18 hemispheres of nine patients in the positive control group who has normal vasodilatory reserve, CBF was increased by 26.2{+-}8.1% at 7.5 minutes and 29.3{+-}13.1% at 20 minutes after ACZ administration. Seven patients with and chronic stage unilateral internal carotid artery severe stenosis and/or occlusion were evaluated as the test group. Case of unaffected side, CBF was increased by 17.6{+-}6.9% at 7.5 minutes and 24.8{+-}11.3% 20 minutes after ACZ administration. And, increase rate of CBF in the affected side was 2.8{+-}1.6% at 7.5 minutes and 17.3{+-}5.0% at 20 minutes after ACZ administration. In the affected side, timing of the maximum CBF increase caused by ACZ was remarkably delayed. Our method based on {sup 99m}Tc-ECD SPECT also revealed delayed cerebral artery dilation in the affected side. It was suggested that ACZ reaction came out time dependently, as reported by Kuwabara et al. (author)

  1. Early Recurrence and Cerebral Bleeding in Patients With Acute Ischemic Stroke and Atrial Fibrillation: Effect of Anticoagulation and Its Timing: The RAF Study.

    Science.gov (United States)

    Paciaroni, Maurizio; Agnelli, Giancarlo; Falocci, Nicola; Caso, Valeria; Becattini, Cecilia; Marcheselli, Simona; Rueckert, Christina; Pezzini, Alessandro; Poli, Loris; Padovani, Alessandro; Csiba, Laszló; Szabó, Lilla; Sohn, Sung-Il; Tassinari, Tiziana; Abdul-Rahim, Azmil H; Michel, Patrik; Cordier, Maria; Vanacker, Peter; Remillard, Suzette; Alberti, Andrea; Venti, Michele; Scoditti, Umberto; Denti, Licia; Orlandi, Giovanni; Chiti, Alberto; Gialdini, Gino; Bovi, Paolo; Carletti, Monica; Rigatelli, Alberto; Putaala, Jukka; Tatlisumak, Turgut; Masotti, Luca; Lorenzini, Gianni; Tassi, Rossana; Guideri, Francesca; Martini, Giuseppe; Tsivgoulis, Georgios; Vadikolias, Kostantinos; Liantinioti, Chrissoula; Corea, Francesco; Del Sette, Massimo; Ageno, Walter; De Lodovici, Maria Luisa; Bono, Giorgio; Baldi, Antonio; D'Anna, Sebastiano; Sacco, Simona; Carolei, Antonio; Tiseo, Cindy; Acciarresi, Monica; D'Amore, Cataldo; Imberti, Davide; Zabzuni, Dorjan; Doronin, Boris; Volodina, Vera; Consoli, Domenico; Galati, Franco; Pieroni, Alessio; Toni, Danilo; Monaco, Serena; Baronello, Mario Maimone; Barlinn, Kristian; Pallesen, Lars-Peder; Kepplinger, Jessica; Bodechtel, Ulf; Gerber, Johannes; Deleu, Dirk; Melikyan, Gayane; Ibrahim, Faisal; Akhtar, Naveed; Mosconi, Maria Giulia; Bubba, Valentina; Silvestri, Ilenia; Lees, Kennedy R

    2015-08-01

    The best time for administering anticoagulation therapy in acute cardioembolic stroke remains unclear. This prospective cohort study of patients with acute stroke and atrial fibrillation, evaluated (1) the risk of recurrent ischemic event and severe bleeding; (2) the risk factors for recurrence and bleeding; and (3) the risks of recurrence and bleeding associated with anticoagulant therapy and its starting time after the acute stroke. The primary outcome of this multicenter study was the composite of stroke, transient ischemic attack, symptomatic systemic embolism, symptomatic cerebral bleeding and major extracranial bleeding within 90 days from acute stroke. Of the 1029 patients enrolled, 123 had 128 events (12.6%): 77 (7.6%) ischemic stroke or transient ischemic attack or systemic embolism, 37 (3.6%) symptomatic cerebral bleeding, and 14 (1.4%) major extracranial bleeding. At 90 days, 50% of the patients were either deceased or disabled (modified Rankin score ≥3), and 10.9% were deceased. High CHA2DS2-VASc score, high National Institutes of Health Stroke Scale, large ischemic lesion and type of anticoagulant were predictive factors for primary study outcome. At adjusted Cox regression analysis, initiating anticoagulants 4 to 14 days from stroke onset was associated with a significant reduction in primary study outcome, compared with initiating treatment before 4 or after 14 days: hazard ratio 0.53 (95% confidence interval 0.30-0.93). About 7% of the patients treated with oral anticoagulants alone had an outcome event compared with 16.8% and 12.3% of the patients treated with low molecular weight heparins alone or followed by oral anticoagulants, respectively (P=0.003). Acute stroke in atrial fibrillation patients is associated with high rates of ischemic recurrence and major bleeding at 90 days. This study has observed that high CHA2DS2-VASc score, high National Institutes of Health Stroke Scale, large ischemic lesions, and type of anticoagulant administered

  2. Circadian time structure of circulating plasma lipid peroxides, antioxidant enzymes and other small molecules in peptic ulcers.

    Science.gov (United States)

    Singh, Ranjana; Singh, Rajesh Kumar; Masood, Tariq; Tripathi, Anil Kumar; Mahdi, Abbas Ali; Singh, Raj Kumar; Schwartzkopff, Othild; Cornelissen, Germaine

    2015-12-07

    The circadian rhythm, as part of a broad time structure (chronome) of lipid peroxides and antioxidant defense mechanisms may relate to prevention, efficacy and management of preventive and curative chronotherapy. Fifty newly diagnosed patients with peptic ulcers, 30-45 years of age, and 60 age-matched clinically healthy volunteers were synchronized for one week with diurnal activity from about 06:00 to about 22:00 and nocturnal rest. Breakfast was served around 08:30, lunch around 13:30 and dinner around 20:30. Drugs known to affect the free-radical systems were not taken. Blood samples were collected at 6-hour intervals for 24h under standardized, presumably 24-hour synchronized conditions. Plasma lipid peroxides, in the form of malondialdehyde (MDA), blood superoxide dismutase (SOD), glutathione peroxide (GPx), glutathione reductase (GR), catalase (CAT) activities, and serum total protein, albumin, ascorbic acid, total serum cholesterol, and HDL-cholesterol concentrations were determined. By population-mean cosinor analysis, a marked circadian variation was demonstrated for all variables in healthy subjects and in ulcer patients (pascorbic acid, and HDL-C. They also had smaller circadian amplitude of SOD, CAT, GPx, GR, ascorbic acid, T-C, and HDL-C, but larger circadian amplitude of MDA and albumin. As compared to healthy subjects, the circadian acrophase of ulcer patients occurred later for MDA and GR and earlier for GPx. Mapping circadian rhythms, important chronome components that include trends with age and extra-circadian components characterizing antioxidants and pro-oxidants, is needed for exploring their putative role as markers in the treatment and management of peptic ulcers. Copyright © 2015. Published by Elsevier B.V.

  3. Timing training in three children with diplegic cerebral palsy: Short- and long-term effects on upper-limb movement organization and functioning

    Directory of Open Access Journals (Sweden)

    Anna-Maria eJohansson

    2014-03-01

    Full Text Available Despite the great need of interventions to maintain and improve motor functions in children with diplegic cerebral palsy (DCP, scientific evaluations of existing training methods are rare. This study aimed to explore individual effects of synchronized metronome training (SMT on motor timing, spatio-temporal movement organization, and subjective experiences of changes in upper-limb functions in three children with DCP. All children participated in an individualized 4-week/12 session SMT training regime. Measurements before training (Pre, after training (Post1 and at 6 months post completed training (Post2 were made by the applied SMT training equipment, optoelectronic registrations of goal-directed upper-limb movements, and a questionnaire assessing subjective experiences of changes in upper-limb functions and usability. In general, the training regime was shown to have little effect on motor timing. However, some positive changes in spatio-temporal movement organization were found. Two children also reported substantial long-lasting positive changes in subjective experiences of hand/arm functionality in terms of increased movement control and reduced muscle tone. For these children, parallel kinematic findings also indicated smoother and faster movement trajectories that remained at Post2. Although highly individualized, the shown improvements in upper-limb kinematics and subjective experiences of improved functionality of the hands/arms for two of the cases warrant further explorations of SMT outcomes in children with DCP.

  4. Color doppler evaluation of the influence of type of delivery, sex, postnatal age and time post feeding on full term healthy newborns cerebral blood flow Doppler colorido na avaliação da influência do tipo de parto, sexo, idade pós-natal e tempo pós-mamada no fluxo sanguíneo cerebral em recém-nascidos a termo e saudáveis

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Aranha

    2009-06-01

    Full Text Available OBJECTIVE: The purpose of this study was to evaluate with Color Doppler the influence of type of delivery, sex, postnatal age and time post feeding on full term healthy newborns cerebral blood flow. METHOD: 50 newborns were studied. The Doppler parameters, peak-systolic velocity, end-diastolic velocity, mean velocity, pulsatility index and resistance index, were measured in the anterior cerebral artery, middle cerebral artery, posterior cerebral artery, and basilar artery. The data were compared and analyzed by statistical tests. Informed consent was obtained from all parents, and the study was approved by institutional ethical committee and review board. RESULTS: We observed not statistically significant differences on cerebral blood flow Doppler parameters in relation to type of delivery, sex, postnatal age and feeding in full term healthy newborns. CONCLUSION: We believe that the knowledge of these cerebral hemodynamic profile of newborns in the first days of life can contribute in an accurate interpretation of cranial Doppler abnormal findings when pathologic flow velocities are analyzed.OBJETIVO: O objetivo deste estudo foi avaliar com Doppler colorido a influência do tipo de parto, sexo, idade pós-natal e tempo pós-mamada no fluxo sanguíneo cerebral de recém-nascidos a termo e saudáveis. MÉTODO: Foram estudados 50 recém-nascidos. A Dopplervelocimetria foi obtida nas artérias cerebral anterior, cerebral média, cerebral posterior e basilar. Os parâmetros foram comparados e analisados pelos testes estatísticos Esta pesquisa foi aprovada pela comissão ética e de pós-graduação das instituições e o consentimento informado dos pais foi obtido em todos os casos. RESULTADOS: Não observamos diferenças estatísticamente significativas na Dopplervelocimetria do fluxo sanguíneo cerebral em relação ao tipo de parto, sexo, idade pós-natal e tempo pós-mamada dos recém-nascidos normais e saudáveis estudados. CONCLUS

  5. Cerebral Palsy (For Teens)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Cerebral Palsy KidsHealth / For Teens / Cerebral Palsy What's in this ... do just what everyone else does. What Is Cerebral Palsy? Cerebral palsy (CP) is a disorder of the ...

  6. Sino-Danish Brain Circulation

    DEFF Research Database (Denmark)

    Bertelsen, Rasmus Gjedssø; Du, Xiangyun; Søndergaard, Morten Karnøe

    2014-01-01

    China is faced with urgent needs to develop an economically and environmentally sustainable economy based on innovation and knowledge. Brain circulation and research and business investments from the outside are central for this development. Sino-American brain circulation and research...... and investment by overseas researchers and entrepreneurs are well described. In that case, the US is the center of global R&D and S&T. However, the brain circulation and research and investments between a small open Scandinavian economy, such as Denmark, and the huge developing economy of China are not well...... understood. In this case, Denmark is very highly developed, but a satellite in the global R&D and S&T system. With time and the growth of China as a R&D and S&T power house, both Denmark and China will benefit from brain circulation between them. Such brain circulation is likely to play a key role in flows...

  7. Functional stability of cerebral circulatory system

    Science.gov (United States)

    Moskalenko, Y. Y.

    1980-01-01

    The functional stability of the cerebral circulation system seems to be based on the active mechanisms and on those stemming from specific of the biophysical structure of the system under study. This latter parameter has some relevant criteria for its quantitative estimation. The data obtained suggest that the essential part of the mechanism for active responses of cerebral vessels which maintains the functional stability of this portion of the vascular system, consists of a neurogenic component involving central nervous structures localized, for instance, in the medulla oblongata.

  8. Thermograpic study of upper extremities in patients with cerebral palsy

    Science.gov (United States)

    Lampe, R.; Kawelke, S.; Mitternacht, J.; Turova, V.; Blumenstein, T.; Alves-Pinto, A.

    2015-03-01

    Trophic disorders like reduced skin blood circulation are well-known epiphenomenon of cerebral palsy (CP). They can influence quality of life and can lead to skin damages and, as a consequence, to decubitus. Therefore, it is important to analyse temperature regulation in patients with CP. Thermal imaging camera FLIR BCAM SD was used to study the dependency of skin blood circulation in upper extremities of patients with CP on hand dominance, hand force and hand volume. The hand force was evaluated using a conventional dynamometer. The hand volume was measured with a volumeter. A cold stress test for hands was applied in 22 patients with CP and 6 healthy subjects. The warming up process after the test was recorded with the thermal camera. It was confirmed that the hands of patients warm up slower comparing to healthy persons. The patients' working hands warm up faster than non-working ones. A slight correlation was established between the hand grip force of the working hands and their warm up time. No correlation was found between the warming up time and the volume of the hand. The results confirm our assumption that there is a connection of peripheral blood circulation to upper limb motor functions.

  9. Predictability of motor outcome according to the time of diffusion tensor imaging in patients with cerebral infarct

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Yong Hyun [Yeungnam College of Science and Technology, Department of Physical Therapy, Taegu (Korea, Republic of); Jeoung, Yong Jae [Yeungnam University, Department of Physical Medicine and Rehabilitation, College of Medicine, Taegu (Korea, Republic of); Lee, Jun [Yeungnam University, Department of Neurology, College of Medicine, Taegu (Korea, Republic of); Son, Su Min; Jang, Sung Ho [Yeungnam University 317-1, Department of Physical Medicine and Rehabilitation, College of Medicine, Taegu (Korea, Republic of); Kim, Saeyoon [Yeungnam University, Department of Pediatrics, College of Medicine, Taegu (Korea, Republic of); Kim, Chulseung [Medical Devices Clinical Trial Center of Yeungnam University Hospital, Taegu (Korea, Republic of)

    2012-07-15

    Predictability of diffusion tensor imaging tractography (DTT) for motor outcome can differ according to the time of DTT. We attempted to compare the predictability for motor outcome according to the time of diffusion tensor imaging (DTI) by analyzing the corticospinal tract (CST) integrity on DTT in patients with corona radiata (CR) infarct. Seventy-one consecutive hemiparetic patients with CR infarct were recruited. Motor function of the affected extremities was measured twice: at onset and at 6 months from onset. According to the time of DTI, patients were classified into two groups: the early scanning group (ES group) within 14 days since stroke onset; and the late scanning group (LS group) 15-28 days. Motor outcome was compared with the CST integrity on DTT. Motor prognosis was predicted from scan time of DTI and the CST integrity on DTT in the logistic regression model. According to separate regression analysis, the CST integrity of the late group was found to predict MI score (OR = 14.000, 95% CI = 3.194-61.362, p < 0.05), whereas the CST integrity of the early group was not found to predict MI score. In terms of both positive and negative predictabilities, we found that predictability of DTT for motor outcome was better in patients who were scanned later (15-28 days after onset) than in patients who were scanned earlier (1-14 days after onset). (orig.)

  10. Predictability of motor outcome according to the time of diffusion tensor imaging in patients with cerebral infarct

    International Nuclear Information System (INIS)

    Kwon, Yong Hyun; Jeoung, Yong Jae; Lee, Jun; Son, Su Min; Jang, Sung Ho; Kim, Saeyoon; Kim, Chulseung

    2012-01-01

    Predictability of diffusion tensor imaging tractography (DTT) for motor outcome can differ according to the time of DTT. We attempted to compare the predictability for motor outcome according to the time of diffusion tensor imaging (DTI) by analyzing the corticospinal tract (CST) integrity on DTT in patients with corona radiata (CR) infarct. Seventy-one consecutive hemiparetic patients with CR infarct were recruited. Motor function of the affected extremities was measured twice: at onset and at 6 months from onset. According to the time of DTI, patients were classified into two groups: the early scanning group (ES group) within 14 days since stroke onset; and the late scanning group (LS group) 15-28 days. Motor outcome was compared with the CST integrity on DTT. Motor prognosis was predicted from scan time of DTI and the CST integrity on DTT in the logistic regression model. According to separate regression analysis, the CST integrity of the late group was found to predict MI score (OR = 14.000, 95% CI = 3.194-61.362, p < 0.05), whereas the CST integrity of the early group was not found to predict MI score. In terms of both positive and negative predictabilities, we found that predictability of DTT for motor outcome was better in patients who were scanned later (15-28 days after onset) than in patients who were scanned earlier (1-14 days after onset). (orig.)

  11. How does the interaction of presumed timing, location and extent of the underlying brain lesion relate to upper limb function in children with unilateral cerebral palsy?

    Science.gov (United States)

    Mailleux, Lisa; Klingels, Katrijn; Fiori, Simona; Simon-Martinez, Cristina; Demaerel, Philippe; Locus, Marlies; Fosseprez, Eva; Boyd, Roslyn N; Guzzetta, Andrea; Ortibus, Els; Feys, Hilde

    2017-09-01

    Upper limb (UL) function in children with unilateral cerebral palsy (CP) vary largely depending on presumed timing, location and extent of brain lesions. These factors might exhibit a complex interaction and the combined prognostic value warrants further investigation. This study aimed to map lesion location and extent and assessed whether these differ according to presumed lesion timing and to determine the impact of structural brain damage on UL function within different lesion timing groups. Seventy-three children with unilateral CP (mean age 10 years 2 months) were classified according to lesion timing: malformations (N = 2), periventricular white matter (PWM, N = 42) and cortical and deep grey matter (CDGM, N = 29) lesions. Neuroanatomical damage was scored using a semi-quantitative MRI scale. UL function was assessed at body function and activity level. CDGM lesions were more pronounced compared to PWM lesions (p = 0.0003). Neuroanatomical scores were correlated with a higher degree to UL function in the CDGM group (r s  = -0.39 to r s  = -0.84) compared to the PWM group (r rb  = -0.42 to r s  = -0.61). Regression analysis found lesion location and extent to explain 75% and 65% (p < 0.02) respectively, of the variance in AHA performance in the CDGM group, but only 24% and 12% (p < 0.03) in the PWM group. In the CDGM group, lesion location and extent seems to impact more on UL function compared to the PWM group. In children with PWM lesions, other factors like corticospinal tract (re)organization and structural connectivity may play an additional role. Copyright © 2017 European Paediatric Neurology Society. All rights reserved.

  12. Comparison of 2 protocols to increase circulating progesterone concentration before timed artificial insemination in lactating dairy cows with or without elevated body temperature.

    Science.gov (United States)

    Pereira, M H C; Wiltbank, M C; Guida, T G; Lopes, F R; Vasconcelos, J L M

    2017-10-01

    Two treatments designed to increase circulating progesterone concentration (P4) during preovulatory follicle development were compared. One treatment used 2 intravaginal P4 implants (controlled internal drug-releasing inserts; CIDR) and the other used a GnRH treatment at beginning of the protocol. Lactating Holstein cows that had been diagnosed as nonpregnant were randomly assigned to receive timed artificial insemination (TAI) following 1 of 2 treatments (n = 1,638 breedings): (1) GnRH: CIDR+ 2 mg of estradiol (E2) benzoate + 100 µg of GnRH on d -11, PGF 2α on d -4, CIDR withdrawal + 1.0 mg of E2-cypionate + PGF 2α ) on d -2, and TAI on d 0; or (2) 2CIDR: 2 CIDR + 2 mg of E2-benzoate on d -11, 1 CIDR withdrawn + PGF 2α on d -4, second CIDR withdrawn + 1.0 mg of E2-cypionate + PGF 2α on d -2, and TAI on d 0. Milk yield was measured daily between d 0 and d 7. Rectal temperature was measured using a digital thermometer at d 0 and 7, and elevated body temperature was defined as an average rectal temperature ≥39.1°C. Pregnancy diagnoses were performed on d 32 and 60 after TAI. We detected no effect of treatments on pregnancy per AI or pregnancy loss regardless of elevated body temperature, body condition score, parity, milk yield, or presence or absence of a corpus luteum (CL) on d -11 or d -4. Pregnancy per AI at 60 d was reduced [elevated body temperature = 22.8% (162/709), no elevated body temperature 34.1% (279/817)] and pregnancy loss tended to increase [elevated body temperature = 20.2% (41/203), no elevated body temperature 14.4% (47/326)] in cows with elevated body temperature. Various physiological measurements associated with greater fertility were also reduced in cows with elevated body temperature, such as percentage of cows with a CL at PGF 2α (decreased 7.9%), ovulatory follicle diameter (decreased 0.51 mm), expression of estrus (decreased 5.1%), and ovulation near TAI (decreased 2.8%) compared with cows without elevated body temperature. A

  13. A compact and realistic cerebral cortical layout derived from prewhitened resting-state fMRI time series: Cherniak's adjacency rule, size law, and metamodule grouping upheld.

    Science.gov (United States)

    Lewis, Scott M; Christova, Peka; Jerde, Trenton A; Georgopoulos, Apostolos P

    2012-01-01

    We used hierarchical tree clustering to derive a functional organizational chart of 52 human cortical areas (26 per hemisphere) from zero-lag correlations calculated between single-voxel, prewhitened, resting-state BOLD fMRI time series in 18 subjects. No special "resting-state networks" were identified. There were four major features in the resulting tree (dendrogram). First, there was a strong clustering of homotopic, left-right hemispheric areas. Second, cortical areas were concatenated in multiple, partially overlapping clusters. Third, the arrangement of the areas revealed a layout that closely resembled the actual layout of the cerebral cortex, namely an orderly progression from anterior to posterior. And fourth, the layout of the cortical areas in the tree conformed to principles of efficient, compact layout of components proposed by Cherniak. Since the tree was derived on the basis of the strength of neural correlations, these results document an orderly relation between functional interactions and layout, i.e., between structure and function.

  14. A compact and realistic cerebral cortical layout derived from prewhitened resting-state fMRI time series: Cherniak's adjacency rule, size law, and metamodule grouping upheld

    Science.gov (United States)

    Lewis, Scott M.; Christova, Peka; Jerde, Trenton A.; Georgopoulos, Apostolos P.

    2012-01-01

    We used hierarchical tree clustering to derive a functional organizational chart of 52 human cortical areas (26 per hemisphere) from zero-lag correlations calculated between single-voxel, prewhitened, resting-state BOLD fMRI time series in 18 subjects. No special “resting-state networks” were identified. There were four major features in the resulting tree (dendrogram). First, there was a strong clustering of homotopic, left-right hemispheric areas. Second, cortical areas were concatenated in multiple, partially overlapping clusters. Third, the arrangement of the areas revealed a layout that closely resembled the actual layout of the cerebral cortex, namely an orderly progression from anterior to posterior. And fourth, the layout of the cortical areas in the tree conformed to principles of efficient, compact layout of components proposed by Cherniak. Since the tree was derived on the basis of the strength of neural correlations, these results document an orderly relation between functional interactions and layout, i.e., between structure and function. PMID:22973198

  15. Reliability of Three Dimentional Pseudo-continuous Arterial Spin Labeling: A Volumetric Cerebral Perfusion Imaging with Different Post-labeling Time and Functional State in Health Adults.

    Science.gov (United States)

    Liu, Meng-Qi; Chen, Zhi-Ye; Ma, Lin

    2018-03-30

    Objective To evaluate the reliability of three dimensional spiral fast spin echo pseudo-continuous arterial spin labeling (3D pc-ASL) in measuring cerebral blood flow (CBF) with different post-labeling delay time (PLD) in the resting state and the right finger taping state. Methods 3D pc-ASL and three dimensional T1-weighted fast spoiled gradient recalled echo (3D T1-FSPGR) sequence were applied to eight healthy subjects twice at the same time each day for one week interval. ASL data acquisition was performed with post-labeling delay time (PLD) 1.5 seconds and 2.0 seconds in the resting state and the right finger taping state respectively. CBF mapping was calculated and CBF value of both the gray matter (GM) and white matter (WM) was automatically extracted. The reliability was evaluated using the intraclass correlation coefficient (ICC) and Bland and Altman plot. Results ICC of the GM (0.84) and WM (0.92) was lower at PLD 1.5 seconds than that (GM, 0.88; WM, 0.94) at PLD 2.0 seconds in the resting state, and ICC of GM (0.88) was higher in the right finger taping state than that in the resting state at PLD 1.5 seconds. ICC of the GM and WM was 0.71 and 0.78 for PLD 1.5 seconds and PLD 2.0 seconds in the resting state at the first scan, and ICC of the GM and WM was 0.83 and 0.79 at the second scan, respectively. Conclusion This work demonstrated that 3D pc-ASL might be a reliable imaging technique to measure CBF over the whole brain at different PLD in the resting state or controlled state.

  16. Time-scale and extent at which large-scale circulation modes determine the wind and solar potential in the Iberian Peninsula

    International Nuclear Information System (INIS)

    Jerez, Sonia; Trigo, Ricardo M

    2013-01-01

    The North Atlantic Oscillation (NAO), the East Atlantic (EA) and the Scandinavian (SCAND) modes are the three main large-scale circulation patterns driving the climate variability of the Iberian Peninsula. This study assesses their influence in terms of solar (photovoltaic) and wind power generation potential (SP and WP) and evaluates their skill as predictors. For that we use a hindcast regional climate simulation to retrieve the primary meteorological variables involved, surface solar radiation and wind speed. First we identify that the maximum influence of the various modes occurs on the interannual variations of the monthly mean SP and WP series, being generally more relevant in winter. Second we find that in this time-scale and season, SP (WP) varies up to 30% (40%) with respect to the mean climatology between years with opposite phases of the modes, although the strength and the spatial distribution of the signals differ from one month to another. Last, the skill of a multi-linear regression model (MLRM), built using the NAO, EA and SCAND indices, to reconstruct the original wintertime monthly series of SP and WP was investigated. The reconstructed series (when the MLRM is calibrated for each month individually) correlate with the original ones up to 0.8 at the interannual time-scale. Besides, when the modeled series for each individual month are merged to construct an October-to-March monthly series, and after removing the annual cycle in order to account for monthly anomalies, these correlate 0.65 (0.55) with the original SP (WP) series in average. These values remain fairly stable when the calibration and reconstruction periods differ, thus supporting up to a point the predictive potential of the method at the time-scale assessed here. (letter)

  17. Predicting ischemic mitral regurgitation in patients with acute ST-elevation myocardial infarction: Does time to reperfusion really matter and what is the role of collateral circulation?

    Science.gov (United States)

    Valuckiene, Zivile; Budrys, Povilas; Jurkevicius, Renaldas

    2016-01-15

    Ischemic mitral regurgitation (MR) is an adverse prognostic factor. We aimed to assess the role of time delay from symptom onset to reperfusion, and the impact of collateral circulation to incidence of MR in relation to established echocardiographic and clinical risk factors. Patients with STEMI presenting within 12 h from symptom onset and treated with primary percutaneous coronary intervention (PPCI) at Hospital of Lithuanian University of Health Sciences were enrolled. Echocardiography was performed after PPCI. Based on MR grade, patients were divided into no significant MR (NMR, grade 0-I MR, N = 102) and ischemic MR (IMR, grade ≥ 2 MR, N = 71) groups. Well-developed collaterals were defined as grade ≥ 2 by Rentrop classification. Continuous variables were compared by independent samples Student's T-test. Multivariate logistic regression analysis was used to identify independent predictors of ischemic MR. Time to reperfusion, MI localization, TIMI flow before/after PCI was similar between the groups. IMR group patients were elder, more often females and non-smokers, had lower body mass index, higher prevalence of multi-vessel coronary artery disease (CAD), better-developed collateral supply, greater left ventricular end-diastolic diameter index, left atrial index, pulmonary artery systolic pressure and lower ejection fraction. Multivariate logistic regression analysis revealed that ischemic MR is predicted by female gender, well-developed collateral supply, presence of multi-vessel CAD, and lower EF. In acute STEMI significant MR is unrelated to ischemic time and is predicted by female gender, lower EF, multi-vessel CAD and well-developed collateral supply to the infarct region.

  18. Novel Interactive Data Visualization: Exploration of the ESCAPE Trial (Endovascular Treatment for Small Core and Anterior Circulation Proximal Occlusion With Emphasis on Minimizing CT to Recanalization Times) Data.

    Science.gov (United States)

    Brigdan, Matthew; Hill, Michael D; Jagdev, Abhijeet; Kamal, Noreen

    2018-01-01

    The ESCAPE (Endovascular Treatment for Small Core and Anterior Circulation Proximal Occlusion With Emphasis on Minimizing CT to Recanalization Times) randomized clinical trial collected a large diverse data set. However, it is difficult to fully understand the effects of the study on certain patient groups and disease progression. We developed and evaluated an interactive visualization of the ESCAPE trial data. We iteratively designed an interactive visualization using Python's Bokeh software library. The design was evaluated through a user study, which quantitatively evaluated its efficiency and accuracy against traditional modified Rankin Scalegraphic. Qualitative feedback was also evaluated. The novel interactive visualization of the ESCAPE data are publicly available at http://escapevisualization.herokuapp.com/. There was no difference in the efficiency and accuracy when comparing the use of the novel with the traditional visualization. However, users preferred the novel visualization because it allowed for greater exploration. Some insights obtained through exploration of the ESCAPE data are presented. Novel interactive visualizations can be applied to acute stroke trial data to allow for greater exploration of the results. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01778335. © 2017 American Heart Association, Inc.

  19. Fractionation and current time trends of PCB congeners: evolvement of distributions 1950–2010 studied using a global atmosphere-ocean general circulation model

    Directory of Open Access Journals (Sweden)

    G. Lammel

    2012-08-01

    Full Text Available PCBs are ubiquitous environmental pollutants expected to decline in abiotic environmental media in response to decreasing primary emissions since the 1970s. A coupled atmosphere-ocean general circulation model with embedded dynamic sub-models for atmospheric aerosols and the marine biogeochemistry and air-surface exchange processes with soils, vegetation and the cryosphere is used to study the transport and fate of four PCB congeners covering a range of 3–7 chlorine atoms.

    The change of the geographic distribution of the PCB mixture reflects the sources and sinks' evolvement over time. Globally, secondary emissions (re-volatilisation from surfaces are on the long term increasingly gaining importance over primary emissions. Secondary emissions are most important for the congeners with 5–6 chlorine atoms. Correspondingly, the levels of these congeners are predicted to decrease slowest. Changes in congener mixture composition (fractionation are characterized both geographically and temporally. In high latitudes enrichment of the lighter, less persistent congeners and more delayed decreasing levels in response to decreasing emissions are found. The delivery of the contaminants to high latitudes is predicted to be more efficient than previously suggested. The results suggest furthermore that the effectiveness of emission control measures may significantly vary among substances. The trends of decline of organic contaminant levels in the abiotic environmental media do not only vary with latitude (slow in high latitudes, but do also show longitudinal gradients.

  20. Microparticles generated during chronic cerebral ischemia deliver proapoptotic signals to cultured endothelial cells

    International Nuclear Information System (INIS)

    Schock, Sarah C.; Edrissi, Hamidreza; Burger, Dylan; Cadonic, Robert; Hakim, Antoine; Thompson, Charlie

    2014-01-01

    Highlights: • Microparticles are elevated in the plasma in a rodent model of chronic cerebral ischemia. • These microparticles initiate apoptosis in cultured cells. • Microparticles contain caspase 3 and they activate receptors for TNF-α and TRAIL. - Abstract: Circulating microparticles (MPs) are involved in many physiological processes and numbers are increased in a variety of cardiovascular disorders. The present aims were to characterize levels of MPs in a rodent model of chronic cerebral hypoperfusion (CCH) and to determine their signaling properties. MPs were isolated from the plasma of rats exposed to CCH and quantified by flow cytometry. When MPs were added to cultured endothelial cells or normal rat kidney cells they induced cell death in a time and dose dependent manner. Analysis of pellets by electron microscopy indicates that cell death signals are carried by particles in the range of 400 nm in diameter or less. Cell death involved the activation of caspase 3 and was not a consequence of oxidative stress. Inhibition of the Fas/FasL signaling pathway also did not improve cell survival. MPs were found to contain caspase 3 and treating the MPs with a caspase 3 inhibitor significantly reduced cell death. A TNF-α receptor blocker and a TRAIL neutralizing antibody also significantly reduced cell death. Levels of circulating MPs are elevated in a rodent model of chronic cerebral ischemia. MPs with a diameter of 400 nm or less activate the TNF-α and TRAIL signaling pathways and may deliver caspase 3 to cultured cells

  1. Microparticles generated during chronic cerebral ischemia deliver proapoptotic signals to cultured endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Schock, Sarah C. [Ottawa Hospital Research Institute, Neuroscience, 451 Smyth Road, Ottawa, ON K1H 8M5 (Canada); Edrissi, Hamidreza [University of Ottawa, Neuroscience Graduate Program, 451 Smyth Road, Ottawa, ON K1H 8M5 (Canada); Burger, Dylan [Ottawa Hospital Research Institute, Kidney Centre, 451 Smyth Road, Ottawa, ON K1H 8M5 (Canada); Cadonic, Robert; Hakim, Antoine [Ottawa Hospital Research Institute, Neuroscience, 451 Smyth Road, Ottawa, ON K1H 8M5 (Canada); Thompson, Charlie, E-mail: charliet@uottawa.ca [Ottawa Hospital Research Institute, Neuroscience, 451 Smyth Road, Ottawa, ON K1H 8M5 (Canada)

    2014-07-18

    Highlights: • Microparticles are elevated in the plasma in a rodent model of chronic cerebral ischemia. • These microparticles initiate apoptosis in cultured cells. • Microparticles contain caspase 3 and they activate receptors for TNF-α and TRAIL. - Abstract: Circulating microparticles (MPs) are involved in many physiological processes and numbers are increased in a variety of cardiovascular disorders. The present aims were to characterize levels of MPs in a rodent model of chronic cerebral hypoperfusion (CCH) and to determine their signaling properties. MPs were isolated from the plasma of rats exposed to CCH and quantified by flow cytometry. When MPs were added to cultured endothelial cells or normal rat kidney cells they induced cell death in a time and dose dependent manner. Analysis of pellets by electron microscopy indicates that cell death signals are carried by particles in the range of 400 nm in diameter or less. Cell death involved the activation of caspase 3 and was not a consequence of oxidative stress. Inhibition of the Fas/FasL signaling pathway also did not improve cell survival. MPs were found to contain caspase 3 and treating the MPs with a caspase 3 inhibitor significantly reduced cell death. A TNF-α receptor blocker and a TRAIL neutralizing antibody also significantly reduced cell death. Levels of circulating MPs are elevated in a rodent model of chronic cerebral ischemia. MPs with a diameter of 400 nm or less activate the TNF-α and TRAIL signaling pathways and may deliver caspase 3 to cultured cells.

  2. Cerebral Vasculitis

    Directory of Open Access Journals (Sweden)

    Fariborz Khorvash

    2017-02-01

    Full Text Available Introduction: Vasculitis is an inflammation systems may be involved of blood vessels due to various origins. Vessels of the peripheral and/or central nervous. Vasculitis of the CNS is rare and occurs in the context of systemic diseases or as primary angiitis of the CNS. Epidemiology: The overall incidence of primary vasculitis is about 40/1,000,000 persons [excluding giant cell (temporal arteritis, GCA]. Its incidence increases with age. The incidence of GCA is much higher (around 200/1,000,000 persons in the age group[50 years. Clinical Presentation: Clinical and pathological presentation in CNS vasculitis represents a wide spectrum. Among others, headache, cranial nerve affections, encephalopathy, seizures, psychosis, myelitis, stroke, intracranial haemorrhage and aseptic meningoencephalitis are described. Primary and secondary vasculitides leading more frequently to CNS manifestations are discussed. Primary and secondary Vasculitides: Including Giant Cell (Temporal Arteritis , Takayasu arteritis, Polyarteritis nodosa, Primary angiitis of the CNS, Wegener’s granulomatosis, and Connective tissue diseases, such as systemic lupus erythematosus (SLE, scleroderma, rheumatoid arthritis, mixed connective disease and Sjögren syndrome, are systemic immune-mediated diseases that lead to multiple organ affections. Cerebral Vasculitis: Imaging and Differential Diagnosis: Vasculitides represent a heterogeneous group of inflammatory diseases that affect blood vessel walls of varying calibers (inflammatory vasculopathy. Since the devastating symptoms of CNS vasculitis are at least partially reversible, early diagnosis and appropriate treatment are important. In order to establish a differential diagnosis clinical features, disease progression, age of onset, blood results, as well as CSF examinations have to be taken into consideration. Neuroimaging techniques, such as MRI and DSA, play a central role in the diagnosis and disease monitoring .The diagnostic

  3. Hypothermia reduces cerebral metabolic rate and cerebral blood flow in newborn pigs

    International Nuclear Information System (INIS)

    Busija, D.W.; Leffler, C.W.

    1987-01-01

    The authors examined effects of hypothermia on cerebral metabolic rate and cerebral blood flow in anesthetized, newborn pigs (1-4 days old). Cerebral blood flow (CBF) was determined with 15-μm radioactive microspheres. Regional CBF ranged from 44 to 66 ml·min -1 ·100 g -1 , and cerebral metabolic rate was 1.94 ± 0.23 ml O 2 ·100 g -1 ·min -1 during normothermia (39 degree C). Reduction of rectal temperature to 34-35 degree C decreased CBF and cerebral metabolic rate 40-50%. In another group of piglets, they examined responsiveness of the cerebral circulation to arterial hypercapnia during hypothermia. Although absolute values for normocapnic and hypercapnic CBF were reduced by hypothermia and absolute values for normocapnic and hypercapnic cerebrovascular resistance were increased, the percentage changes from control in these variables during hypercapnia were similar during normothermia and hypothermia. In another group of animals that were maintained normothermic and exposed to two episodes of hypercapnia, there was no attenuation of cerebrovascular dilation during the second episode. They conclude that hypothermia reduces CBF secondarily to a decrease in cerebral metabolic rate and that percent dilator responsiveness to arterial hypercapnia is unaltered when body temperature is reduced

  4. Real-time measurement of cerebral blood flow during and after repetitive transcranial magnetic stimulation: A near-infrared spectroscopy study.

    Science.gov (United States)

    Park, Eunhee; Kang, Min Jae; Lee, Ahee; Chang, Won Hyuk; Shin, Yong-Il; Kim, Yun-Hee

    2017-07-13

    To confirm the interhemispheric modulation induced by low-frequency repetitive transcranial magnetic stimulation (rTMS) over the primary motor cortex, real-time regional cerebral blood flow (rCBF) was assessed using functional near-infrared spectroscopy (fNIRS) in the contralateral primary motor cortex (M1) and premotor cortex (PM). Ten right-handed healthy subjects completed two experimental sessions that were randomly arranged for real or sham rTMS session. In the real rTMS session, fNIRS data were acquired from the right M1 and PM area, while the motor hot spot of the left M1 was stimulated with 1Hz rTMS for 1200 pulses with two boosters. In the sham stimulation session, stimulation was delivered with a disconnected coil. During the real rTMS session, the concentration of oxyhemoglobin ([oxy-Hb]) in the right M1 increased continuously until the end of the stimulation. These changes lasted for 20min, while the right PM did not show a change in [oxy-Hb] concentration. On the other hand, the concentration of deoxy-hemoglobin ([deoxy-Hb]) decreased continuously in the right M1 and PM during the real rTMS stimulation, and this change lasted for 20min after the stimulation. The sham stimulation did not exhibit any significant change in both [oxy-Hb] and [deoxy-Hb] concentration during or after the stimulation. Application of 1Hz rTMS over M1 resulted in changes of rCBF in contralateral M1 and PM, which seemed to constitute a function of interhemispheric modulation of rTMS. The fNIRS data was able to detect this physiological change of neuromodulatory action of rTMS in real-time. Copyright © 2017. Published by Elsevier B.V.

  5. Left Atrium Papillary Fibroelastomas: A Cause of Cerebral Emboli

    Directory of Open Access Journals (Sweden)

    A. G. Ciss

    2012-01-01

    Full Text Available Papillary fibroelastomas are cardiac benign tumours. Among the benign cardiac tumor, papillary fibroelastomas are reported second after myxomas. Most often diagnosed incidentally, papillary fibroelastomas may embolize to cerebral circulation. Valvular locations are predominant; location in left atrium is rare. In this paper, we present a case of papillary fibroelastoma located in left atrium with symptoms of cerebral embolization. Transoesophageal echocardiography diagnosed a mobile mass. The patient was treated with surgical resection without further embolic complication.

  6. The influence of transcutaneous electrical neurostimulation (TENS) on human cerebral blood flow velocities

    NARCIS (Netherlands)

    ter Laan, Mark; van Dijk, J. Marc C.; Elting, Jan-Willem J.; Fidler, Vaclav; Staal, Michiel J.

    It has been shown that transcutaneous electrical neurostimulation (TENS) reduces sympathetic tone. Spinal cord stimulation (SCS) has proven qualities to improve coronary, peripheral, and cerebral blood circulation. Therefore, we postulate that TENS and SCS affect the autonomic nervous system in

  7. Dynamic alteration of regional cerebral blood flow during carotid compression and proof of reversibility

    International Nuclear Information System (INIS)

    Asahi, Kouichi; Hori, M; Hamasaki, N; Sato, S; Nakanishi, H; Kuwatsuru, R; Sasai, K; Aoki, S

    2012-01-01

    It is difficult to non-invasively visualize changes in regional cerebral blood flow caused by manual compression of the carotid artery. To visualize dynamic changes in regional cerebral blood flow during and after manual compression of the carotid artery. Two healthy volunteers were recruited. Anatomic features and flow directions in the circle of Willis were evaluated with time-of-flight magnetic resonance angiography (MRA) and two-dimensional phase-contrast (2DPC) MRA, respectively. Regional cerebral blood flow was visualized with territorial arterial spin-labeling magnetic resonance imaging (TASL-MRI). TASL-MRI and 2DPC-MRA were performed in three states: at rest, during manual compression of the right carotid artery, and after decompression. In one volunteer, time-space labeling inversion pulse (Time-SLIP) MRA was performed to confirm collateral flow. During manual carotid compression, in one volunteer, the right thalamus changed to be fed only by the vertebrobasilar system, and the right basal ganglia changed to be fed by the left internal carotid artery. In the other volunteer, the right basal ganglia changed to be fed by the vertebrobasilar system. 2DPC-MRA showed that the flow direction changed in the right A1 segment of the anterior cerebral artery and the right posterior communicating artery. Perfusion patterns and flow directions recovered after decompression. Time-SLIP MRA showed pial vessels and dural collateral circulation when the right carotid artery was manually compressed. Use of TASL-MRI and 2DPC-MRA was successful for non-invasive visualization of the dynamic changes in regional cerebral blood flow during and after manual carotid compression

  8. Vertigo-related cerebral blood flow changes on magnetic resonance imaging.

    Science.gov (United States)

    Chang, Feiyan; Li, Zhongshi; Xie, Sheng; Liu, Hui; Wang, Wu

    2014-11-01

    A prospective study using magnetic resonance imaging on a consecutive cohort of patients with cervical vertigo. To quantitatively investigate the cerebral blood flow (CBF) changes associated with cervical vertigo by using 3-dimensional pseudocontinuous arterial spin labeling. Previous studies reported blood flow velocity reduction in posterior circulation during vertigo. However, the detailed information of CBF related to cervical vertigo has not been provided. A total of 33 patients with cervical vertigo and 14 healthy volunteers were recruited in this study. Three-dimensional pseudocontinuous arterial spin labeling was performed on each subject to evaluate the CBF before and after the cervical hyperextension-hyperflexion movement tests, which was used to induce cervical vertigo. Repeated-measures analysis of variance was conducted to assess the effect of subjects and tests. There were time effects of CBF in the territory of bilateral superior cerebellar artery, bilateral posterior cerebral artery, bilateral middle cerebral artery, and right anterior cerebral artery, but no group effect was observed. The analysis of CBF revealed a significant main effect of tests (P=0.024) and participants (P=0.038) in the dorsal pons. Cervical vertigo onset may be related to CBF reduction in the dorsal pons, which sequentially evokes the vestibular nuclei. 2.

  9. [Cerebral aspergillosis].

    Science.gov (United States)

    Tattevin, P; Jauréguiberry, S; Gangneux, J-P

    2004-05-01

    The brain is almost always a localization of invasive aspergillosis, after hematogenous spread from pulmonary aspergillosis. Brain aspergilosis is not rare and is one of the worst prognosis factors of invasive aspergillosis. The incidence of this severe mycosis is currently on the rise due to the development of major immunosuppressive treatments. Brain aspergillosis is noteworthy for its vascular tropism, leading to infectious cerebral vasculitis, mainly involving thalamoperforating and lenticulostriate arteries, with a high frequency of thalamic or basal nuclei lesions. Extra-neurologic features that suggest this diagnosis are: i) risk factors for invasive aspergillosis (major or prolonged neutropenia, hematologic malignancies, prolonged corticosteroid treatment, bone marrow or solid organ transplant, AIDS); ii) persistent fever not responding to presumptive antibacterial treatment; iii) respiratory signs (brain aspergillosis is associated with pulmonary aspergillosis in 80 to 95 p. 100 of cases). Perspectives. Two recent major improvements in brain aspergillosis management must be outlined: i) for diagnostic purposes, the development of testing for Aspergillus antigenemia (a non-invasive procedure with good diagnostic value for invasive aspergillosis); ii) for therapeutic purposes, the demonstration that voriconazole is better than amphotericin B in terms of clinical response, tolerance and survival, for all types of invasive aspergillosis, the benefit being probably even greater in case of brain aspergillosis because of the good diffusion of voriconazole into the central nervous system. Brain aspergillosis is a severe emerging opportunistic infection for which diagnostic and therapeutic tools have recently improved. Thus, this diagnostic must be suspected early, especially in the immunocompromised patient, in the event of respiratory symptoms and when the brain lesions are localized in the central nuclei and the thalamus.

  10. Dynamic digitized cerebral parenchymography

    International Nuclear Information System (INIS)

    Theron, J.; Alachkar, F.; Nelson, M.; Mazia, D.

    1992-01-01

    Aortic arch injections centred on the head have been performed routinely in patients with cerebral ischaemia. Digital angiograms with modified windowing (low and narrow) have been used. This 'cerebral' arch injection allows much improved analysis of the cerebral parenchymal vascularization, giving better understanding of hemispheric ischaemia and making the decision about revascularization more rational. (orig.)

  11. Biodynamics circulation

    CERN Document Server

    Fung, Y C

    1984-01-01

    This book is a continuation of my Biomechanics.The first volume deals with the mechanical properties of living tissues. The present volume deals with the mechanics ofcirculation. A third volume willdeal with respiration, fluid balance, locomotion, growth, and strength. This volume is called Bio­ dynamics in order to distinguish it from the first volume. The same style is followed. My objective is to present the mechanical aspects ofphysiology in precise terms ofmechanics so that the subject can become as lucid as physics. The motivation of writing this series of books is, as I have said in the preface to the first volume, to bring biomechanics to students ofbioengineer­ ing, physiology, medicine, and mechanics. I have long felt a need for a set of books that willinform the students ofthe physiological and medical applica­ tions ofbiomechanics,and at the same time develop their training in mechan­ ics. In writing these books I have assumed that the reader already has some basic training in mechanics, to a ...

  12. [Role of cerebral hemodynamics in the mechanism of development of acquired myopia in schoolchildren].

    Science.gov (United States)

    Iastrebtseva, T A; Demidova, T E; Polikarpova, V E

    2008-01-01

    Rheoencephalography was used to study cerebral venous circulation in 199 schoolchildren aged 12-15 years who had emmetropia, pseudomyopia, and myopia. Tonometry was carried out in 39 persons. Cerebral venous hemodynamic dysfunction was more frequently encountered in schoolchildren with myopia than in those with emmetropia. Intraocular pressure was significantly higher only in schoolchildren with high myopia than in the controls.

  13. CT classification and clinical prognosis of cerebral infarction in the area of middle cerebral artery

    International Nuclear Information System (INIS)

    Konno, Jyoji

    1983-01-01

    Computerized tomographies (CT) were repeatedly scanned on 70 patients with cerebral infarction in the middle cerebral artery. Low density area (LDA) was measured with HounFsfield's Unit (HU) and studied on the progressive changes. Classification of LDA was attempted and studied on correlation with mass effect, contrast enhancement, angiographical findings, clinical symptoms and prognosis. It was considered that important points of diagnosis of cerebral infarction were timing of examination of CT and determination of LDA with HUF. It was also thought that CT classification of LDA was usefull to estimate prognosis of the patients with cerebral infarction. (author)

  14. Cerebral Aneurysms

    Science.gov (United States)

    ... person's age, general health, pre-existing neurological conditions, adn time between rupture and medical attention. Early diagnosis ... person's age, general health, pre-existing neurological conditions, adn time between rupture and medical attention. Early diagnosis ...

  15. Effects of Milrinone continuous intravenous infusion on global cerebral oxygenation and cerebral vasospasm after cerebral aneurysm surgical clipping

    Directory of Open Access Journals (Sweden)

    Mohamed A. Ghanem

    2014-01-01

    Conclusions: Milrinone improved significantly the global cerebral oxygenation and reduced the incidence of cerebral vasospasm during the dangerous period of cerebral spasm after cerebral aneurysm clipping.

  16. Optimizing {sup 18}F-FDG PET/CT imaging of vessel wall inflammation: the impact of {sup 18}F-FDG circulation time, injected dose, uptake parameters, and fasting blood glucose levels

    Energy Technology Data Exchange (ETDEWEB)

    Bucerius, Jan [Icahn School of Medicine at Mount Sinai, Translational and Molecular Imaging Institute, One Gustave L. Levy Place, P.O. Box 1234, New York, NY (United States); Mount Sinai School of Medicine, Department of Radiology, New York, NY (United States); Maastricht University Medical Center, Department of Nuclear Medicine, Maastricht (Netherlands); Maastricht University Medical Center, Cardiovascular Research Institute Maastricht (CARIM), Maastricht (Netherlands); University Hospital, RWTH Aachen, Department of Nuclear Medicine, Aachen (Germany); Mani, Venkatesh; Fayad, Zahi A. [Icahn School of Medicine at Mount Sinai, Translational and Molecular Imaging Institute, One Gustave L. Levy Place, P.O. Box 1234, New York, NY (United States); Mount Sinai School of Medicine, Department of Radiology, New York, NY (United States); Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); Moncrieff, Colin [Icahn School of Medicine at Mount Sinai, Translational and Molecular Imaging Institute, One Gustave L. Levy Place, P.O. Box 1234, New York, NY (United States); Mount Sinai School of Medicine, Department of Radiology, New York, NY (United States); Machac, Josef [Mount Sinai School of Medicine, Division of Nuclear Medicine, Department of Radiology, New York, NY (United States); Fuster, Valentin [Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); The Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid (Spain); Farkouh, Michael E. [Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); Mount Sinai School of Medicine, Cardiovascular Imaging Clinical Trials Unit, New York, NY (United States); Tawakol, Ahmed [Massachusetts General Hospital, Harvard University, Cardiac MR PET CT Program, Boston, MA (United States); Rudd, James H.F. [Cambridge University, Division of Cardiovascular Medicine, Cambridge (United Kingdom)

    2014-02-15

    {sup 18}F-FDG PET is increasingly used for imaging of vessel wall inflammation. However, limited data are available on the impact of methodological variables, i.e. prescan fasting glucose, FDG circulation time and injected FDG dose, and of different FDG uptake parameters, in vascular FDG PET imaging. Included in the study were 195 patients who underwent vascular FDG PET/CT of the aorta and the carotids. Arterial standardized uptake values ({sub mean}SUV{sub max}), target-to-background ratios ({sub mean}TBR{sub max}) and FDG blood-pool activity in the superior vena cava (SVC) and the jugular veins (JV) were quantified. Vascular FDG uptake values classified according to the tertiles of prescan fasting glucose levels, the FDG circulation time, and the injected FDG dose were compared using ANOVA. Multivariate regression analyses were performed to identify the potential impact of all variables described on the arterial and blood-pool FDG uptake. Tertile analyses revealed FDG circulation times of about 2.5 h and prescan glucose levels of less than 7.0 mmol/l, showing a favorable relationship between arterial and blood-pool FDG uptake. FDG circulation times showed negative associations with aortic{sub mean}SUV{sub max} values as well as SVC and JV FDG blood-pool activity, but positive correlations with aortic and carotid{sub mean}TBR{sub max} values. Prescan glucose levels were negatively associated with aortic and carotid{sub mean}TBR{sub max} and carotid{sub mean}SUV{sub max} values, but were positively correlated with SVC blood-pool uptake. The injected FDG dose failed to show any significant association with vascular FDG uptake. FDG circulation times and prescan blood glucose levels significantly affect FDG uptake in the aortic and carotid walls and may bias the results of image interpretation in patients undergoing vascular FDG PET/CT. The injected FDG dose was less critical. Therefore, circulation times of about 2.5 h and prescan glucose levels less than 7.0 mmol

  17. Microembolism after cerebral angiography

    International Nuclear Information System (INIS)

    Manaka, Hiroshi; Sakai, Hideki; Nagata, Izumi

    2000-01-01

    Acute microemboli are detected more precisely with the recently developed diffusion-weighted MR imaging (DWI). We happened to obtain 24 DWIs after 350 diagnostic cerebral angiographies in 1999. DWIs after cerebral angiographies showed bright lesions in 7 patients (28%), of whom 6 had no neurological symptoms after cerebral angiography. Seven of the 24 patients had risk factors for arteriosclerosis. Only one patient had embolic events due to angiography. Microemboli related to cerebral angiographies are inevitable in some patients. Most are silent, however, we should investigate the cause of microemboli and should make cerebral angiography safer. (author)

  18. Definition of the key target volume in radiosurgical management of arteriovenous malformations: a new dynamic concept based on angiographic circulation time.

    Science.gov (United States)

    Valle, Ramiro Del; Zenteno, Marco; Jaramillo, José; Lee, Angel; De Anda, Salvador

    2008-12-01

    The cumulative experience worldwide indicates complete radiosurgical obliteration rates of brain arteriovenous malformations (AVMs) ranging from 35 to 90%. The purpose of this study was to propose a strategy to increase the obliteration rate for AVMs through the dynamic definition of the key target volume (KTV). A prospective series of patients harboring an AVM was assessed using digital subtraction angiography in which a digital counter was used to measure the several stages of the frame-by-frame circulation time. All the patients were analyzed using dynamic measurement planning to define the KTV, corresponding to the volume of the shunt with the least vascular resistance and the earliest venous drainage. All patients underwent catheter-based angiography, a subgroup was additionally assessed by means of a superselective catheterization, and among these a further subgroup received embolization. The shunts were also categorized according to their angioarchitectural type: fistulous, plexiform, or mixed. The authors applied the radiosurgery-based grading system (RBGS) as well to find a correlation with the obliteration rate. This series includes 44 patients treated by radiosurgery; global angiography was performed for all patients, including dynamic measurement planning. Eighty-four percent of them underwent superselective catheterization, and 50% of the total population underwent embolization. In the embolized arm of the study, the pretreatment volume was up to 120 ml. In patients with a single treatment, the mean volume was 8.5 ml, and the median volume was 6.95 +/- 4.56 ml (mean +/- standard deviation), with a KTV of up to 15 ml. For prospectively staged radiosurgery, the mean KTV was 28 ml. The marginal radiation dose was 18-22 Gy, with a mean of dose 20 Gy. The mean RBGS score was 1.70. The overall obliteration rate was 91%, including the repeated radiosurgery group (4 patients), in which 100% showed complete obliteration. The overall permanent deficit was 2 of

  19. Circulation of Stars

    Science.gov (United States)

    Boitani, P.

    2016-01-01

    Since the dawn of man, contemplation of the stars has been a primary impulse in human beings, who proliferated their knowledge of the stars all over the world. Aristotle sees this as the product of primeval and perennial “wonder” which gives rise to what we call science, philosophy, and poetry. Astronomy, astrology, and star art (painting, architecture, literature, and music) go hand in hand through millennia in all cultures of the planet (and all use catasterisms to explain certain phenomena). Some of these developments are independent of each other, i.e., they take place in one culture independently of others. Some, on the other hand, are the product of the “circulation of stars.” There are two ways of looking at this. One seeks out forms, the other concentrates on the passing of specific lore from one area to another through time. The former relies on archetypes (for instance, with catasterism), the latter constitutes a historical process. In this paper I present some of the surprising ways in which the circulation of stars has occurred—from East to West, from East to the Far East, and from West to East, at times simultaneously.

  20. CT findings of middle cerebral artery occlusion

    International Nuclear Information System (INIS)

    Shiokawa, Yoshiaki; Saito, Isamu; Segawa, Hiromu; Fujimaki, Takamitsu; Tsutsumi, Kazuo

    1987-01-01

    In each case, we selected the CT scan showing the maximum extent of the low-density area (LDA) during the course of the occlusion and classified the findings into the following five types: basal ganglia type, extensive subcortical type, hemispheric type, branch type, and normal (no LDA) type. The angiographic occlusion sites of MCA were divided into 4 patterns; the origin of MCA, the distal M1 portion, MCA trifurcation, and one branch of the M2. The overall mortality rate was 33 %, while the morbidity rate was 53 %. The older the patient, the poorer the prognosis. In the 17 cases of MCA-origin occlusion, 12 cases (71 %) showed the basal ganglia type of LDA; their prognoses varied. In the 12 cases of MCA trifurcation occlusion, 10 cases (83 %) revealed an extensive subcortical type of LDA, and all showed a poor prognosis. In the MCA occlusion, the angiography-CT correlation seemed to depend on where and how the occlusion had occurred. Cerebral thrombosis frequently occurred at the origin of MCA, while cerebral embolism was more usually found to occlude the MCA trifurcation. In order to assess the collateral circulation quantitatively, we determined the IC-M2 time, that is, the conduction time of the contrast media from the intracranial carotid siphone (IC) to the insular portion of the MCA (M2) through the leptomeningeal anastomosis. Of the 29 cases admitted within 24 hours after the onset and which yet showed no LDA on the initial CT scan, all 13 cases with IC-M2 times of less than 5 seconds showed the basal ganglia type of LDA. On the other hand, the 16 cases with IC-M2 times of more than 5 seconds always demonstrated a large LDA, of either the extensive subcortical type or the hemispheric type. This IC-M2 time is useful in anticipating the extent of infarction before a CT scan demonstrates LDA and in predicting a patient's prognosis in the acute stage. (J.P.N.)

  1. CT findings of middle cerebral artery occlusion

    Energy Technology Data Exchange (ETDEWEB)

    Shiokawa, Yoshiaki; Saito, Isamu; Segawa, Hiromu; Fujimaki, Takamitsu; Tsutsumi, Kazuo

    1987-04-01

    In each case, we selected the CT scan showing the maximum extent of the low-density area (LDA) during the course of the occlusion and classified the findings into the following five types: basal ganglia type, extensive subcortical type, hemispheric type, branch type, and normal (no LDA) type. The angiographic occlusion sites of MCA were divided into 4 patterns; the origin of MCA, the distal M1 portion, MCA trifurcation, and one branch of the M2. The overall mortality rate was 33 %, while the morbidity rate was 53 %. The older the patient, the poorer the prognosis. In the 17 cases of MCA-origin occlusion, 12 cases (71 %) showed the basal ganglia type of LDA; their prognoses varied. In the 12 cases of MCA trifurcation occlusion, 10 cases (83 %) revealed an extensive subcortical type of LDA, and all showed a poor prognosis. In the MCA occlusion, the angiography-CT correlation seemed to depend on where and how the occlusion had occurred. Cerebral thrombosis frequently occurred at the origin of MCA, while cerebral embolism was more usually found to occlude the MCA trifurcation. In order to assess the collateral circulation quantitatively, we determined the IC-M2 time, that is, the conduction time of the contrast media from the intracranial carotid siphone (IC) to the insular portion of the MCA (M2) through the leptomeningeal anastomosis. Of the 29 cases admitted within 24 hours after the onset and which yet showed no LDA on the initial CT scan, all 13 cases with IC-M2 times of less than 5 seconds showed the basal ganglia type of LDA. On the other hand, the 16 cases with IC-M2 times of more than 5 seconds always demonstrated a large LDA, of either the extensive subcortical type or the hemispheric type. This IC-M2 time is useful in anticipating the extent of infarction before a CT scan demonstrates LDA and in predicting a patient's prognosis in the acute stage. (J.P.N.).

  2. Advances in computer applications in radioactive tracer studies of the circulation

    International Nuclear Information System (INIS)

    Wagner, H.N. Jr.; Klingensmith, W.C. III; Knowles, L.G.; Lotter, M.G.; Natarajan, T.K.

    1977-01-01

    Advances in computer technology since the last IAEA symposium on medical radionuclide imaging have now made possible a new approach to the study of physiological processes that promise to improve greatly our perception of body functions and structures. We have developed procedures, called ''compressed time imaging'' (CTI), that display serial images obtained over periods of minutes and hours at framing rates of approximately 16 to 60 per minute. At other times, ''real'' or ''expanded time imaging'' is used, depending on the process under study. Designed initially to study the beating heart, such multidimensional time studies are now being extended to the cerebral and other regional circulations, as well as to other organ systems. The improved imaging methods provide a new approach to space and time in the study of physiology and are supplemented by quantitative analysis of data displayed on the television screen of the computer. (author)

  3. Obliteration dynamics in cerebral arteriovenous malformations after cyberknife radiosurgery: quantification with sequential nidus volumetry and 3-tesla 3-dimensional time-of-flight magnetic resonance angiography.

    Science.gov (United States)

    Wowra, Berndt; Muacevic, Alexander; Tonn, Jörg-Christian; Schoenberg, Stefan O; Reiser, Maximilian; Herrmann, Karin A

    2009-02-01

    To investigate the time-dependent obliteration of cerebral arteriovenous malformations (cAVM) after CyberKnife radiosurgery (CKRS) (Accuray, Inc., Sunnyvale, CA) by means of sequential 3-T, 3-dimensional (3D), time-of-flight (TOF) magnetic resonance angiography (MRA), and volumetry of the arteriovenous malformation (AVM) nidus. In this prospective study, 3D TOF MRA was performed on 20 patients with cAVMs treated by single-fraction CKRS. Three-dimensional TOF MRA was performed on a 3-T, 32-channel magnetic resonance scanner (Magnetom TIM Trio; Siemens Medical Solutions, Erlangen, Germany) with isotropic voxel size at a spatial resolution of 0.6 x 0.6 x 0.6 mm3. The time-dependent relative decay of the transnidal blood flow evidenced by 3D TOF MRA was referred to as "obliteration dynamics." Volumetry of the nidus size was performed with OsiriX imaging software (OsiriX Foundation, Geneva, Switzerland). All patients had 3 to 4 follow-up examinations at 3- to 6-month intervals over a minimum follow-up period of 9 months. Subtotal obliteration was determined if the residual nidus volume was 5% or less of the initial nidus volume. Stata/IC software (Version 10.0; Stata Corp., College Station, TX) was used for statistical analysis and to identify potential factors of AVM obliteration. Regarding their clinical status, case history, and pretreatments, the participants of this study represent difficult-to-treat cAVM patients. The median nidus volume was 1.8 mL (range, 0.4-12.5 mL); the median minimum dose prescribed to the nidus was 22 Gy (range, 16-24 Gy) delivered to the 67% isodose line (range, 55-80%). CKRS was well tolerated, with complications in 2 patients. No further hemorrhages occurred after RS, except 1 small and clinically inapparent incident. The median follow-up period after RS was 25.0 months (range, 11.7-36.8 months). After RS, a statistically significant obliteration was observed in all patients. However, the obliteration dynamics of the cAVMs showed a

  4. MR angiography of cerebral aneurysms

    International Nuclear Information System (INIS)

    Miki, Hitoshi; Tanada, Shuji; Sakaki, Saburo; Hamamoto, Ken; Sadamoto, Kazuhiko.

    1992-01-01

    Time-of-flight (TOF) MR angiography (MRA) and phase-contrast (PC) MRA are examined clinically for evaluating cerebral aneurysms. In the morphological diagnosis of cerebral aneurysms, three-dimensional (3D) MRA is superior to two-dimensional (2D) MRA because 3D MRA has a higher S/N ratio and a higher spatial resolution. However, it is difficult to decide which, 3D TOF MRA or 3D PC MRA, is superior, for both methods have many scan parameters. In our study, 3D PC MRA was performed using two methods; one had the same acquisition time as 3D TOF MRA, while the other had the same spatial resolution as 3D TOF MRA. The detectability of aneurysms by each MRA method was evaluated in comparison with 3D TOF MRA. In fifteen patients (6 males and 9 females), a total of 16 cerebral aneurysms (3 ruptured and 13 unruptured) were studied. The lesion sizes ranged from 2.5 to 18 mm. All the 16 lesions were examined by means of 3D TOF MRA, 3D PC MRA, and conventional angiography. MR imaging was performed with a 1.5 tesla MRI system (Signa). All of the 16 cerebral aneurysms were detected by 3D TOF MRA, while only 11 of them were detected by 3D PC MRA. When 3D PC MRA was performed with the same acquisition time as 3D TOF MRA, 3D PC MRA was superior in showing one of the 7 aneurysms. When 3D PC MRA was performed with same spatial resolution as 3D TOF MRA, 3D PC MRA was superior in showing two of the 10 aneurysms. 3D TOF MRA was superior to 3D PC MRA in the detection of cerebral aneurysms because of the long acquisition times and the different flow velocity, which induced different signal intensities between the aneurysms and parent arteries in 3D PC MRA. 3D PC MRA was superior to 3D TOF MRA in patients with large thrombotic aneurysms of the internal carotid artery. We consider that 3D TOF MRA should be the first choice for screening and following-up cerebral aneurysms. 3D PC MRA should then be performed for large cerebral aneurysms in addition to 3D TOF MRA. (author)

  5. Radiology of liver circulation

    International Nuclear Information System (INIS)

    Hermine, C.L.

    1985-01-01

    This book proposes that careful evaluation of the arterioportogram is the cornerstone in assessing portal flow obstruction, being the most consistent of all observations including liver histology, portal venous pressure, size and number of portosystemic collaterals, and wedged hepatic venous pressure. Very brief chapters cover normal hepatic circulation and angiographic methods. Contrast volumes and flow rates for celiac, hepatic, and superior mesenteric injection are given, with the timing for venous phase radiographs. In the main body of the text, portal obstruction is divided very simply into presinusoidal (all proximal causes) and postsinusoidal (all distal causes, including Budd-Chiari). Changes are discussed regarding the splenic artery and spleen; hepatic artery and its branches; portal flow rate and direction; and arterioportal shunting and portosystemic collateral circulation in minimal, moderate, severe, and very severe portal obstruction and in recognizable entities such as prehepatic portal and hepatic venous obstructions. The major emphasis in this section is the recognition and understanding of flow changes by which level and severity of obstruction are assessed (not simply the anatomy of portosystemic collateral venous flow). Excellent final chapters discuss the question of portal hypertension without obstruction, and the contribution of arterioportography to the treatment of portal hypertension, again with an emphasis on hemodynamics before and after shunt surgery. There is a fascinating final chapter on segmental intrahepatic obstruction without portal hypertension that explains much of the unusual contrast enhancement sometimes seen in CT scanning of hepatic mass lesions

  6. Diagnosis and endovascular treatment of multiple cerebral venous and venous sinuses thrombosis

    International Nuclear Information System (INIS)

    Li Baomin; Zhang Ji; Yin Ling; Huang Xusheng; Jiang Jinli; Liu Jun; Lang Senyang; Zhou Dingbiao; Zhu Ke

    2000-01-01

    Objective: Eighty-five cases with multiple cerebral venous and venous sinuses thrombosis including the diagnosis and endovascular therapy were reported. Methods: The long T2 and short T1 signals in the related regions of multiple venous sinuses on MRI and prolonged blood circulation time of the brain with tortuous dilatation of vein in angiography were the important characteristics for the diagnosis. Of the 85 cases, the treatment procedures were consisted of injecting urokinase intermittently via common carotid artery and intra-sinus contact thrombolysis as well as warfarin intake orally. Results: Intracranial pressure of 80 cases reduced down between 230 and 300 mm H 2 O, and clinical deficits were markedly improved within 10 days. Re-angiography of 18 cases revealed recanalization partly in 5 cases and circulation time appeared near normal i 8 cases during one week after therapy. Conclusions: Combined intraarterial thrombolysis consecutively with general anticoagulation for the treatment of multiple thrombosis in cerebral venous sinuses may be one of the effective means

  7. NMR imaging of cerebral infarction

    International Nuclear Information System (INIS)

    Takusagawa, Yoshihiko; Yamaoka, Naoki; Doi, Kazuaki; Okada, Keisei

    1987-01-01

    One hundred and five patients with cerebral infarction were studied by nuclear magnetic resonance (NMR) CT (resistive type of magnet with strength of 0.1 tesla) and X-ray CT. Pulse sequences used saturation recovery (Tr = 600 mSec), Inversion recovery (Tr = 500 mSec, Td = 300 mSec) and spin echo (Tr = 1500 mSec, Te = 40, 80, 120, 160 mSec). Fifteen cases were examined by NMR-CT within 24 hours from onset. Proton NMR imaging could not detect cerebral ischemia as early as 2 hours after onset, but except could detect the lesions in Se image the area of cerebral infarct 3 hours after onset. After 5 hours from onset image changes in SE were evident and corresponded to the area of cerebral infarct, but image changes in IR could not fully delineate the infarcted area. NMR images of 41 year-old woman with cerebral embolism by MCA trunck occlusion associated with mitral stenosis were presented, and NMR-CT was examined 10 hours, 9th and 43th days after episode of MCA occlusion. Sixty patents (64 times) with lacunar infarction were studied by NMR-CT and X-ray CT. The inversion recovery images were used mainly for detection of lesions and comparison with X-ray CT. In 160 lesions which were detected by NMR-CT or X-ray CT, could 156 lesions be detected by NMR-CT and 78 lesions by X-ray CT. Inversion recovery images were more useful for detection of lacunes than X-ray CT. Calculated T1 and T2 values prolonged with time course from onset. (author)

  8. Evaluation of cerebral blood flow, cerebral metabolism and cerebral function by magnetic resonance imaging

    International Nuclear Information System (INIS)

    Tanaka, Chuzo; Higuchi, Toshihiro; Umeda, Masahiro; Naruse, Shoji; Horikawa, Yoshiharu; Ueda, Satoshi; Furuya, Seiichi.

    1995-01-01

    The magnetic resonance (MR) method has the unique potentiality of detecting cerebral metabolites, cerebral blood flow and brain functions in a noninvasive fashion. We have developed several MR techniques to detect these cerebral parameters with the use of clinical MRI scanners. By modifying the MR spectroscopy (MRS) technique, both 31 P- and 1 H-MRS data can be obtained from multiple, localized regions (multi-voxel method) of the brain, and the distribution of each metabolite in the brain can be readily visualized by metabolite mapping. The use of diffusion weighted images (DWI) permits visualization of the anisotropy of water diffusion in white matter, and based on the difference of diffusion coefficiency, the differential diagnosis between epidermoid tumor and arachnoid cyst can be made. By employing dynamic-MRI (Dyn-MRI) with Gd-DTPA administration, it is possible to examine the difference in blood circulation between brain tumor tissue and normal tissue, as well as among different types of brain tumors. By using magnetization transfer contrast (MTC) imaging, it has become possible to detect brain tumors, and with a small dose of Gd-DTPA, to visualize the vascular system. Functional MRI (fMRI) visualizes the activated brain by using conventional gradient echo technique on conventional MRI scanners. This method has the unique characteristic of detecting a brain function with high spatial and temporal resolution by using the intrinsic substance. Moreover, the localization of motor and sensory areas was detected by noninvasive means within few minutes. The fMRI procedure will be used in the future to analyze the higher and complex brain functions. In conclusion, multi-modality MR is a powerful technique that is useful for investigating the pathogenesis of many diseases, and provides a noninvasive analytic modality for studying brain function. (author)

  9. Cerebral vasculitis associated with Schistosoma mansoni infection

    Directory of Open Access Journals (Sweden)

    Camuset Guillaume

    2012-09-01

    Full Text Available Abstract Background Cerebral involvement in schistosomiasis is not rare, but it is underdiagnosed because of the lack of clinical suspicion and the frequency of asymptomatic forms. Neurologic complications are generally supported by granuloma formation around ectopic eggs which have migrated to the brain. Moreover, vascular lesions and cerebral arteritis have been well documented in histopathological studies. Nevertheless, cerebral vasculitis in later stages of the Schistosoma mansoni infection have not yet been described in living subjects. Case presentation A 28-year-old french woman had a stroke linked with cerebral vasculitis, 6 monthes after returning from Burkina-Faso. At the same time, a S. mansoni disseminated infection was diagnosed. She suffered from a new stroke after undertaking praziquantel therapy, which lead us to associate the S. mansoni infection and cerebral vasculitis. Conclusion This is the first report of such association, since cerebral vasculitis has never been described in later stages of the S. mansoni infection. Although the causal link between the two pathologies could not be proved, we suggest that S. mansoni is able to cause severe vascular damage in cerebral vessels. Schistosomiasis must be investigated in the event of a brain infarct in young people, particularly in patients originating or returning from an endemic area.

  10. Posterior cerebral artery involvement in moyamoya disease: initial infarction and angle between PCA and basilar artery.

    Science.gov (United States)

    Lee, Ji Yeoun; Kim, Seung-Ki; Cheon, Jung-Eun; Choi, Jung Won; Phi, Ji Hoon; Kim, In-One; Cho, Byung-Kyu; Wang, Kyu-Chang

    2013-12-01

    Moyamoya disease (MMD) is a chronic cerebrovascular occlusive disease, and progressive involvement of the posterior cerebral artery (PCA) has been reported. However, majority of MMD articles are presenting classic anterior circulation related issues. This study investigates the preoperative factors related to the long-term outcome of posterior circulation in MMD. Retrospective review of 88 MMD patients (166 PCAs in either hemisphere) without symptomatic disease involvement of PCA at initial diagnosis was done. Data at initial diagnosis regarding age, presence of infarction, status of the PCA, type of posterior communicating artery, and the angle between PCA and basilar artery were reviewed. Progressive stenosis of PCA was evaluated by symptom or radiological imaging during follow up. During an average follow up of 8.3 years, 29 out of 166 (18 %) evaluated PCAs showed progressive disease involvement. The average time of progression from the initial operation was 4.9 years, with the latest onset at 10.8 years. The patients who showed progressive stenosis of the PCA tended to be younger, present with infarction, have smaller angle between PCA and basilar artery, and have asymptomatic stenosis of the PCA at initial presentation. However, multivariate analysis confirmed only the presence of initial infarction and a smaller angle between PCA and basilar artery to be significantly associated with progressive stenosis of PCA. Involvement of PCA in MMD may occur in a delayed fashion, years after the completion of revascularization of anterior circulation. Persistent long-term follow-up regarding the posterior circulation is recommended.

  11. Cerebral perfusion studies using Au-195: Investigations into their clinical usefulness and comparisons with the xenon-133 inhalation method

    International Nuclear Information System (INIS)

    Draws, J.

    1989-01-01

    Au-195m cerebral perfusion studies in the diagnosis of blood supply disorders of the brain have only recently leaped into currency. Au-195m is not capable of diffusing. This particular property permits first-pass times of vascular transfer to be determined for cerebral tissues that correlate with the degree of cerebral circulation. In the study described here, attempts were made to shed more light on the clinical usefulness of the method. For this purpose, the record sheets of two cohorts of patients were analysed on a retrospective basis. 1. In 23 patients, where the cerebrovascular disorders were strictly confined to the cerebral hemispheres, the blood supply of the brain was examined on the basis of both Au-195m cerebral perfusion studies and the xenon-133 inhalation method. In the evaluation of the findings based on the Au-195m study the investigator was blinded to the neurological manifestations of the disease and the results from other studies. In 82% of the patients the perfusion mapping using Au-195m was consistent with the clinical symptoms. 2. In a second group of patients, the probable results of the Au-195m perfusion study were forecasted on the basis of the medical history, clinical symptoms and preliminary diagnosis and subsequently compared to those actually obtained. Expected and actual results were found to be in agreement for 88% of cases. The results provided evidence of the suitability of Au-195m cerebral perfusion studies to examine the blood suply of the brain. In view of the fact that the examinations and measurements are relatively uncomplicated, this newly developed method is most likely to be used on a broader basis in the future. (orig./MG) [de

  12. Cerebral blood flow measurement techniques in infants and children

    International Nuclear Information System (INIS)

    Kirsch, J.R.; Traystman, R.J.; Rogers, M.C.

    1985-01-01

    The tremendous growth of interest in neurologic intensive care and in the pathophysiology of the cerebral circulation in the past few years has resulted in increasing numbers of studies that document alterations in cerebral flow during the course of various diseases or as a response to treatment of them. Before pediatricians come to conclusions based on these studies, it is important to have an understanding of the techniques involved. The techniques are complex and difficult but are based on understandable principles. They also have limitations and are subject to misinterpretations. Pediatricians should become knowledgeable about some of these techniques and their limitations because it is likely that they will be applied with increasing frequency in the next several years. We are on the threshold of exciting discoveries in abnormalities of cerebral blood flow and cerebral metabolism not only in critically ill children but also in children with congenital and learning disorders

  13. The Hamburg Oceanic Carbon Cycle Circulation Model. Version 1. Version 'HAMOCC2s' for long time integrations

    Energy Technology Data Exchange (ETDEWEB)

    Heinze, C.; Maier-Reimer, E. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany)

    1999-11-01

    The Hamburg Ocean Carbon Cycle Circulation Model (HAMOCC, configuration HAMOCC2s) predicts the atmospheric carbon dioxide partial pressure (as induced by oceanic processes), production rates of biogenic particulate matter, and geochemical tracer distributions in the water column as well as the bioturbated sediment. Besides the carbon cycle this model version includes also the marine silicon cycle (silicic acid in the water column and the sediment pore waters, biological opal production, opal flux through the water column and opal sediment pore water interaction). The model is based on the grid and geometry of the LSG ocean general circulation model (see the corresponding manual, LSG=Large Scale Geostrophic) and uses a velocity field provided by the LSG-model in 'frozen' state. In contrast to the earlier version of the model (see Report No. 5), the present version includes a multi-layer sediment model of the bioturbated sediment zone, allowing for variable tracer inventories within the complete model system. (orig.)

  14. Cerebral edema in drug addicts

    Directory of Open Access Journals (Sweden)

    Daruši Dragana J.

    2014-01-01

    Full Text Available Background/Aim. The effect of drugs leaves permanent consequences on the brain, organic in type, followed by numerous manifestations, and it significantly affects the development of mental dysfunctions. The clinicians are often given a task to estimate a patient’s personality during treatment or during experts estimate of a drug addict. The aim of this research was to determine the differences, if any, in characteristics of addicts experience and personality traits in drug addicts with or without cerebral edema. Methods. The research was conducted on a sample of 252 male drug addicts, the average age of 23.3 (SD = 4.3 years. Cerebral edema was confirmed on magnetic resonance (MR images of the brain performed during the treatment of the addicts. The participants were tested by the psychologists using Minnesota Multiphasic Personality Inventory (MMPI-201 test, and the data were processed using canonical discriminate analysis within the SPSS program. The dependent variable in the study was cerebral edema. A block of independent variables, designed for the requirements of this study, consisted of two subgroups. The first one consisted of 12 variables describing the relevant characteristics of drug abuse. The second subgroup consisted of 8 psychopathological tendencies in the personality defined by the mentioned test. Results. Cerebral edema was confirmed in 52 (20.63% of the drug addicts. The differences between the groups of drug addicts with and without cerebral edema were determined in the following: the time span of taking drugs (0.301, use of alcohol parallel with drugs (0.466, and treatment for addiction (0.603. In the drug addicts with a cerebral edema, MMPI-201 confirmed the increase in the scales for hypochondria, psychopathic deviations and psychastenia, and the decrease in the scales for schizophrenia and depression. Conclusion. Our study confirmed a possible connection between cerebral edema and personality traits in a number of the

  15. Optimal estimate of the coolant flow in the assemblies of a BWR of natural circulation in real time; Estimacion optima del flujo de refrigerante en los ensambles de un BWR de circulacion natural en tiempo real

    Energy Technology Data Exchange (ETDEWEB)

    Valle H, J.; Morales S, J. B. [UNAM, Facultad de Ingenieria, Division de Estudios de Posgrado, Laboratorio de Analisis de Ingenieria de Reactores Nucleares, Paseo Cuauhnahuac 8532, Col. Progreso, 62550 Jiutepec, Morelos (Mexico); Espinosa P, G., E-mail: julfi_jg@yahoo.com.mx [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico D. F. (Mexico)

    2012-10-15

    The present work exposes the design and the implementation of an advanced controller that allows estimating the coolant flow in the fuel assemblies of a BWR reactor of natural circulation in real time. To be able to reduce the penalizations that are established in the calculations of the operation limits due to the magnitude of the uncertainties in the coolant flows of a natural circulation reactor, is the objective of this research. In this work the construction of the optimal controller that allows estimating the coolant flows in a fuel channels group of the reactor is shown, as well as the operation of this applied to a reduced order model that simulates the dynamics of a natural circulation reactor. The controller design required of an estimator of the valuation variables not directly of the plant and of the estimates use of the local distributions of the coolant flow. The controller construction of the estimator was based mathematically in the filter Kalman whose algorithm allows to be carried out an advanced control of the system. To prove the estimator operation was development a simplified model that reproduces the basic dynamics of the flowing coolant in the reactor, which works as observer of the system, this model is coupled by means of the estimator controller to a detail model of the plant. The results are presented by means of graphics of the interest variables and the estimate flow, and they are documented in the chart that is presented at the end of this article. (Author)

  16. Microwave circulator design

    CERN Document Server

    Linkhart, Douglas K

    2014-01-01

    Circulator design has advanced significantly since the first edition of this book was published 25 years ago. The objective of this second edition is to present theory, information, and design procedures that will enable microwave engineers and technicians to design and build circulators successfully. This resource contains a discussion of the various units used in the circulator design computations, as well as covers the theory of operation. This book presents numerous applications, giving microwave engineers new ideas about how to solve problems using circulators. Design examples are provided, which demonstrate how to apply the information to real-world design tasks.

  17. Cerebral blood flow and oxygen metabolism after subarachnoid hemorrhage

    International Nuclear Information System (INIS)

    Ito, Hidemichi; Sakurai, Takashi; Hayashi, Tatsuo; Hashimoto, Takuo

    2004-01-01

    The mechanism of reduction of cerebral circulation in the early phase of aneurysmal subarachnoid hemorrhage (SAH) has not yet been clarified. Previous studies have variously indicated that cerebral blood flow (CBF) reduction may be due to cerebral vasospasm, an elevation in intracranial pressure (ICP), constriction of intraparenchymal arterioles, or metabolic reduction. The aim of this study is to investigate the relationship between cerebral circulation and oxygen metabolism. In 36 patients with aneurysmal SAH, the values of mean cerebral blood flow (mCBF), cerebral metabolic rate of oxygen (GMRO 2 ) and oxygen extraction fraction (OEF) were measured by using single photon emission computed tomography (SPECT) with arterial blood drawing and oxygen saturation of internal jugular bulb blood (SjO 2 ) in the acute stage (1-3 days after onset) and the spasm stage (7-10 days after onset). The patients in our study were selected by using the following criteria: no history of cerebrovascular or cardiopulmonary diseases; under the age of 70; the ruptured aneurysm was treated by clipping or coil embolization within 72 hours after onset; no symptoms of cerebral vasospasm; no signs of cerebral ischemic change on CT scans. These patients were divided into 2 groups according to the World Federation of Neurological Surgeons (WFNS) grading classification; the mild group (Grades I and II) consisted of 27 cases and the severe group (Grade IV) consisted of 9 cases. We studied differences in mCBF CMRO 2 , and OEF between the mild group and severe group. In the mild group, mCBF, CMRO 2 , and OEF were significantly higher than in the severe group during both the acute and the spasm stage. Also mCBF showed a direct correlation with CMRO 2 . All the patients were kept under the following conditions: the bed was positioned so that the upper body was raised at an angle at 30 deg; blood pressure was maintained at 130-150 mmHg and PaCO 2 of arterial blood was maintained at 35-40 mmHg; ICP

  18. Cerebral venous angioma

    International Nuclear Information System (INIS)

    Inagawa, Tetsuji; Taguchi, Haruyoshi; Kamiya, Kazuko; Yano, Takashi; Nakajima, Reiko

    1984-01-01

    This report presents a 27-year-old male patient who was diagnosed as having cerebral venous angioma in the postero-temporal area by CT scan and cerebral angiography. The patient improved by removing angioma with electrocoagulation of medullary veins. (Namekawa, K.)

  19. Modelling noninvasively measured cerebral signals during a hypoxemia challenge: steps towards individualised modelling.

    Directory of Open Access Journals (Sweden)

    Beth Jelfs

    Full Text Available Noninvasive approaches to measuring cerebral circulation and metabolism are crucial to furthering our understanding of brain function. These approaches also have considerable potential for clinical use "at the bedside". However, a highly nontrivial task and precondition if such methods are to be used routinely is the robust physiological interpretation of the data. In this paper, we explore the ability of a previously developed model of brain circulation and metabolism to explain and predict quantitatively the responses of physiological signals. The five signals all noninvasively-measured during hypoxemia in healthy volunteers include four signals measured using near-infrared spectroscopy along with middle cerebral artery blood flow measured using transcranial Doppler flowmetry. We show that optimising the model using partial data from an individual can increase its predictive power thus aiding the interpretation of NIRS signals in individuals. At the same time such optimisation can also help refine model parametrisation and provide confidence intervals on model parameters. Discrepancies between model and data which persist despite model optimisation are used to flag up important questions concerning the underlying physiology, and the reliability and physiological meaning of the signals.

  20. Perfusion-weighted magnetic resonance imaging detects recurrent isolated vertigo caused by cerebral hypoperfusion.

    Science.gov (United States)

    Xu, Xiaowei; Jiang, Li; Luo, Man; Li, Jiaoxing; Li, Weidong; Sheng, Wenli

    2015-06-01

    The etiology of isolated vertigo has been a substantial diagnostic challenge for both neurologists and otolaryngologists. This study was designed to detect recurrent isolated vertigo due to cerebral hypoperfusion using perfusion-weighted magnetic resonance imaging (PWI). We recruited isolated vertigo patients whose clinical condition was suspected to be caused by hypodynamics of the brain; these individuals formed the case group. We generated two additional groups: a negative group composed of vertigo patients whose symptoms were caused by problems associated with the ear and a healthy control group. Each subject underwent PWI, and seven regions of interest (ROIs) were chosen. The relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), and mean transit time (MTT) were obtained from each ROI. We further calculated the absolute difference of relative parameter values between two mirrored ROIs. The significant difference in the relative MTT from the mirrored cerebellar ROI (|rMTTleft-right|) of the case group was larger than those from the negative and healthy control groups (p = 0.026 and p = 0.038, respectively). Signal differences in |rrCBVleft-right| and |rrCBFleft-right| were not found among the three groups. In summary, disequilibrium in the rMTT of the bilateral cerebellum in the case group implied that hypoperfusion of the posterior circulation could trigger recurrent isolated vertigo and could be shown efficiently using PWI.

  1. AbetaPP/APLP2 family of Kunitz serine proteinase inhibitors regulate cerebral thrombosis.

    Science.gov (United States)

    Xu, Feng; Previti, Mary Lou; Nieman, Marvin T; Davis, Judianne; Schmaier, Alvin H; Van Nostrand, William E

    2009-04-29

    The amyloid beta-protein precursor (AbetaPP) is best recognized as the precursor to the Abeta peptide that accumulates in the brains of patients with Alzheimer's disease, but less is known about its physiological functions. Isoforms of AbetaPP that contain a Kunitz-type serine proteinase inhibitor (KPI) domain are expressed in brain and, outside the CNS, in circulating blood platelets. Recently, we showed that KPI-containing forms of AbetaPP regulates cerebral thrombosis in vivo (Xu et al., 2005, 2007). Amyloid precursor like protein-2 (APLP2), a closely related homolog to AbetaPP, also possesses a highly conserved KPI domain. Virtually nothing is known of its function. Here, we show that APLP2 also regulates cerebral thrombosis risk. Recombinant purified KPI domains of AbetaPP and APLP2 both inhibit the plasma clotting in vitro. In a carotid artery thrombosis model, both AbetaPP(-/-) and APLP2(-/-) mice exhibit similar significantly shorter times to vessel occlusion compared with wild-type mice indicating a prothrombotic phenotype. Similarly, in an experimental model of intracerebral hemorrhage, both AbetaPP(-/-) and APLP2(-/-) mice produce significantly smaller hematomas with reduced brain hemoglobin content compared with wild-type mice. Together, these results indicate that AbetaPP and APLP2 share overlapping anticoagulant functions with regard to regulating thrombosis after cerebral vascular injury.

  2. Cerebral ischemia is exacerbated by extracellular nicotinamide phosphoribosyltransferase via a non-enzymatic mechanism.

    Directory of Open Access Journals (Sweden)

    Bing Zhao

    Full Text Available Intracellular nicotinamide phosphoribosyltransferase (iNAMPT in neuron has been known as a protective factor against cerebral ischemia through its enzymatic activity, but the role of central extracellular NAMPT (eNAMPT is not clear. Here we show that eNAMPT protein level was elevated in the ischemic rat brain after middle-cerebral-artery occlusion (MCAO and reperfusion, which can be traced to at least in part from blood circulation. Administration of recombinant NAMPT protein exacerbated MCAO-induced neuronal injury in rat brain, while exacerbated oxygen-glucose-deprivation (OGD induced neuronal injury only in neuron-glial mixed culture, but not in neuron culture. In the mixed culture, NAMPT protein promoted TNF-α release in a time- and concentration-dependent fashion, while TNF-α neutralizing antibody protected OGD-induced, NAMPT-enhanced neuronal injury. Importantly, H247A mutant of NAMPT with essentially no enzymatic activity exerted similar effects on ischemic neuronal injury and TNF-α release as the wild type protein. Thus, eNAMPT is an injurious and inflammatory factor in cerebral ischemia and aggravates ischemic neuronal injury by triggering TNF-α release from glia cells, via a mechanism not related to NAMPT enzymatic activity.

  3. Validation of housekeeping genes for quantitative real-time PCR in in-vivo and in-vitro models of cerebral ischaemia

    Directory of Open Access Journals (Sweden)

    Serena Joaquín

    2009-06-01

    Full Text Available Abstract Background Studies of gene expression in experimental cerebral ischaemia models can contribute to understanding the pathophysiology of brain ischaemia and to identifying prognostic markers and potential therapeutic targets. The normalization of relative qRT-PCR data using a suitable reference gene is a crucial prerequisite for obtaining reliable conclusions. No validated housekeeping genes have been reported for the relative quantification of the mRNA expression profile activated in in-vitro ischaemic conditions, whereas for the in-vivo model different reference genes have been used. The present study aims to determine the expression stability of ten housekeeping genes (Gapdh, β2m, Hprt, Ppia, Rpl13a, Oaz1, 18S rRNA, Gusb, Ywhaz and Sdha to establish their suitability as control genes for in-vitro and in-vivo cerebral ischaemia models. Results The expression stability of the candidate reference genes was evaluated using the 2-ΔC'T method and ANOVA followed by Dunnett's test. For the in-vitro model using primary cultures of rat astrocytes, all genes analysed except for Rpl13a and Sdha were found to have significantly different levels of mRNA expression. These different levels were also found in the case of the in-vivo model of pMCAO in rats except for Hprt, Sdha and Ywhaz mRNA, where the expression did not vary. Sdha and Ywhaz were identified by geNorm and NormFinder as the two most stable genes. Conclusion We have validated endogenous control genes for qRT-PCR analysis of gene expression in in-vitro and in-vivo cerebral ischaemia models. For normalization purposes, Rpl13a and Sdha are found to be the most suitable genes for the in-vitro model and Sdha and Ywhaz for the in-vivo model. Genes previously used as housekeeping genes for the in-vivo model in the literature were not validated as good control genes in the present study, showing the need for careful evaluation for each new experimental setup.

  4. CaMKII and MEK1/2 inhibition time-dependently modify inflammatory signaling in rat cerebral arteries during organ culture

    DEFF Research Database (Denmark)

    Waldsee, Roya; Eftekhari, Sajedeh; Ahnstedt, Hilda

    2014-01-01

    MKII) II and extracellular signal-regulated kinase1/2 (ERK1/2) on inflammatory mediators in rat cerebral arteries using organ culture as a method for inducing ischemic-like vascular wall changes. METHODS: Rat basilar arteries were cultured in serum-free medium for 0, 3, 6 or 24 hours in the presence...... of phosphorylated c-Jun N-terminal kinase and p-p38, as evaluated by immunohistochemistry. KN93 affected the increase in caspase-3 mRNA expression only when given at the start of incubation, while U0126 had an inhibitory effect when given up to six hours later. Tumor necrosis factor receptor 1 was elevated after...

  5. Radioisotopic evaluation of portal circulation

    International Nuclear Information System (INIS)

    Maliska, C.; Rosenthal, D.

    1986-01-01

    The use of a radio-tracer of portal circulation through the intestine, should prevent cruel punctures in the portal-vein or spleen as it is usually the case with traditional methods in the study of portal-system. The absorption of I-131 and Tc-99m, previously cheked in rabbits presented similar results in dogs. The time of circulation between terminal large-intestine and the liver (t-RF) was determined by external counting at hepatic level by recording radioactivity variation-time. In healthy animals the t-RF was from 20to 60 seconds, with average time of 42 seconds. In 2 animals with partial binding of portal-vein the t-RF went up to 110 and 120 seconds. (Author) [pt

  6. Circulation pump mounting

    International Nuclear Information System (INIS)

    Skalicky, A.

    1976-01-01

    The suspension is described of nuclear reactor circulating pumps enabling their dilatation with a minimum reverse force consisting of spacing rods supported with one end in the anchor joints and provided with springs and screw joints engaging the circulating pump shoes. The spacing rods are equipped with side vibration dampers anchored in the shaft side wall and on the body of the circulating pump drive body. The negative reverse force F of the spacing rods is given by the relation F=Q/l.y, where Q is the weight of the circulating pump, l is the spatial distance between the shoe joints and anchor joints, and y is the deflection of the circulating pump vertical axis from the mean equilibrium position. The described suspension is advantageous in that that the reverse force for the deflection from the mean equilibrium position is minimal, dynamic behaviour is better, and construction costs are lower compared to suspension design used so far. (J.B.)

  7. Development and Characterization of Probe-Based Real Time Quantitative RT-PCR Assays for Detection and Serotyping of Foot-And-Mouth Disease Viruses Circulating in West Eurasia.

    Science.gov (United States)

    Jamal, Syed M; Belsham, Graham J

    2015-01-01

    Rapid and accurate diagnosis of foot-and-mouth disease (FMD) and virus serotyping are of paramount importance for control of this disease in endemic areas where vaccination is practiced. Ideally this virus characterization should be achieved without the need for virus amplification in cell culture. Due to the heterogeneity of FMD viruses (FMDVs) in different parts of the world, region specific diagnostic tests are required. In this study, hydrolysable probe-based real time reverse transcription quantitative polymerase chain reaction (RT-qPCR) assays were developed for specific detection and serotyping of the FMDVs currently circulating in West Eurasia. These assays were evaluated, in parallel with pan-FMDV diagnostic assays and earlier serotype-specific assays, using field samples originating from Pakistan and Afghanistan containing FMD viruses belonging to different sublineages of O-PanAsia, A-Iran05 and Asia-1 (Group-II and Group-VII (Sindh-08)). In addition, field samples from Iran and Bulgaria, containing FMDVs belonging to the O-PanAsiaANT-10 sublineage were also tested. Each of the three primer/probe sets was designed to be specific for just one of the serotypes O, A and Asia-1 of FMDV and detected the RNA from the target viruses with cycle threshold (CT) values comparable with those obtained with the serotype-independent pan-FMDV diagnostic assays. No cross-reactivity was observed in these assays between the heterotypic viruses circulating in the region. The assays reported here have higher diagnostic sensitivity (100% each for serotypes O and Asia-1, and 92% [95% CI = 81.4-100%] for serotype A positive samples) and specificity (100% each for serotypes O, A and Asia-1 positive samples) for the viruses currently circulating in West Eurasia compared to the serotyping assays reported earlier. Comparisons of the sequences of the primers and probes used in these assays and the corresponding regions of the circulating viruses provided explanations for the poor

  8. Development and Characterization of Probe-Based Real Time Quantitative RT-PCR Assays for Detection and Serotyping of Foot-And-Mouth Disease Viruses Circulating in West Eurasia.

    Directory of Open Access Journals (Sweden)

    Syed M Jamal

    Full Text Available Rapid and accurate diagnosis of foot-and-mouth disease (FMD and virus serotyping are of paramount importance for control of this disease in endemic areas where vaccination is practiced. Ideally this virus characterization should be achieved without the need for virus amplification in cell culture. Due to the heterogeneity of FMD viruses (FMDVs in different parts of the world, region specific diagnostic tests are required. In this study, hydrolysable probe-based real time reverse transcription quantitative polymerase chain reaction (RT-qPCR assays were developed for specific detection and serotyping of the FMDVs currently circulating in West Eurasia. These assays were evaluated, in parallel with pan-FMDV diagnostic assays and earlier serotype-specific assays, using field samples originating from Pakistan and Afghanistan containing FMD viruses belonging to different sublineages of O-PanAsia, A-Iran05 and Asia-1 (Group-II and Group-VII (Sindh-08. In addition, field samples from Iran and Bulgaria, containing FMDVs belonging to the O-PanAsiaANT-10 sublineage were also tested. Each of the three primer/probe sets was designed to be specific for just one of the serotypes O, A and Asia-1 of FMDV and detected the RNA from the target viruses with cycle threshold (CT values comparable with those obtained with the serotype-independent pan-FMDV diagnostic assays. No cross-reactivity was observed in these assays between the heterotypic viruses circulating in the region. The assays reported here have higher diagnostic sensitivity (100% each for serotypes O and Asia-1, and 92% [95% CI = 81.4-100%] for serotype A positive samples and specificity (100% each for serotypes O, A and Asia-1 positive samples for the viruses currently circulating in West Eurasia compared to the serotyping assays reported earlier. Comparisons of the sequences of the primers and probes used in these assays and the corresponding regions of the circulating viruses provided explanations for

  9. Leisure-time physical activity and circulating 25-hydroxyvitamin D levels in cancer survivors: a cross-sectional analysis using data from the US National Health and Nutrition Examination Survey.

    Science.gov (United States)

    Yang, Lin; Toriola, Adetunji T

    2017-07-10

    Circulating 25-hydroxyvitamin D (25-OHD) is associated with improved cancer prognosis in some studies, yet it may be a surrogate marker for physical activity. We investigated the associations of leisure-time physical activity (LTPA) with circulating 25-OHD levels in cancer survivors, and determined whether associations differ by indoor and outdoor activity. Cross-sectional study. The US National Health and Nutrition Examination Survey (NHANES). Cancer survivors with available data on demographic information, measures of adiposity, smoking history, self-reported LTPA and circulating 25-OHD levels in five waves of NHANES (2001-2010). Circulating 25-OHD levels. Multivariable linear regression and logistic regression models were used to evaluate the associations of self-reported LTPA with 25-OHD, adjusting for potential confounders. Due to the differences in LTPA measure, the analyses were conducted separately for 2001-2006 and 2007-2010 data. We further estimated associations by indoor and outdoor activity in the 2001-2006 data. There were 1530 cancer survivors (mean age=60.5 years, mean body mass index=28.6 kg/m 2 ). The prevalent cancer sites were breast (19.3%), prostate (18.8%), cervix (10.4%) and colon (8.6%). Compared with inactive cancer survivors, being physically active was associated with higher circulating 25-OHD levels (8.07 nmol/L, 95% CI 4.63 to 11.52) for 2001-2006 data. In the mutually adjusted model, higher outdoor activity (5.83 nmol/L, 95% CI 1.64 to 10.01), but not indoor activity (2.93 nmol/L, 95% CI -1.80 to 7.66), was associated with statistically significantly higher 25-OHD levels. The interaction between indoor and outdoor activities was, however, not significant (p=0.29). The only statistically significant association seen in the 2007-2010 data was among obese cancer survivors. Physical activity, particularly outdoor activity, is associated with higher 25-OHD levels in cancer survivors. In view of the possible beneficial effects

  10. MR findings of cerebral palsy

    International Nuclear Information System (INIS)

    Yoon, Sang Hum; Chang, Seung Kuk; Cho, Mee Young; Park, Dong Woo; Kim, Jong Deok; Eun, Choong Ki

    1994-01-01

    To evaluate the MR findings of brain damage in cerebral palised patients and to correlate it with gestational age and the time of damage. A retrospective analysis was performed in 40 patients who underwent MR scanning for evaluation of brain lesion in clinically diagnosed cerebral palsy. Authors classified the patients into two groups as premature and full-term and compared MR findings of the two groups. Abnormal MR findings were noted in 28 cases (70%). Five out of 6 patients who had been born prematurely showed isolate periventricular white matter lesions. Twenty-three out of 34 patients who had been born at full-term showed abnormal MR findings. Of these 23 patients, migration anomalies in 7 patients, isolate periventricular white matter lesions in 3 patients, and other combined periventricular subcortical white matter and deep gray matter lesions in 14 patients were seen. At least, 10 patients(43%) of full term group showed abnormal MRI findings reflecting intrauterine brain damage and all 5 patients of premature group showed isolate periventricular white matter lesions suggesting immaturity of brain. MRI is thought to be very useful in the assessment of brain damage for the patients with cerebral palsy by recognizing the location of the lesion and estimating the time of damage

  11. MR findings of cerebral palsy

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Sang Hum; Chang, Seung Kuk; Cho, Mee Young; Park, Dong Woo; Kim, Jong Deok; Eun, Choong Ki [Pusan Paik Hospital, Pusan (Korea, Republic of)

    1994-11-15

    To evaluate the MR findings of brain damage in cerebral palised patients and to correlate it with gestational age and the time of damage. A retrospective analysis was performed in 40 patients who underwent MR scanning for evaluation of brain lesion in clinically diagnosed cerebral palsy. Authors classified the patients into two groups as premature and full-term and compared MR findings of the two groups. Abnormal MR findings were noted in 28 cases (70%). Five out of 6 patients who had been born prematurely showed isolate periventricular white matter lesions. Twenty-three out of 34 patients who had been born at full-term showed abnormal MR findings. Of these 23 patients, migration anomalies in 7 patients, isolate periventricular white matter lesions in 3 patients, and other combined periventricular subcortical white matter and deep gray matter lesions in 14 patients were seen. At least, 10 patients(43%) of full term group showed abnormal MRI findings reflecting intrauterine brain damage and all 5 patients of premature group showed isolate periventricular white matter lesions suggesting immaturity of brain. MRI is thought to be very useful in the assessment of brain damage for the patients with cerebral palsy by recognizing the location of the lesion and estimating the time of damage.

  12. Proposal for a universal definition of cerebral infarction.

    Science.gov (United States)

    Saver, Jeffrey L

    2008-11-01

    Cerebral infarction is a leading cause of disability and death worldwide but has no uniform international definition. Recent diagnostic advances have revised fundamental concepts in cerebral and cardiac ischemia. Cardiologists, already possessed of a nosologic framework distinguishing myocardial infarction from unstable angina on the basis of tissue state, promulgated a new "universal" tissue definition of myocardial infarction incorporating insights afforded by assays of cardiac troponin, a serum biomarker exquisitely sensitive to myocardial injury. Concurrently, vascular neurologists proposed a new tissue, rather than time, criterion to distinguish transient ischemia attack from cerebral infarction, responding to perspectives provided by diffusion MRI and cerebral blood volume CT, imaging biomarkers highly sensitive to neuronal injury. To complete this conceptual realignment, vascular neurology must now advance a clear, uniform, and operationalizable tissue definition of cerebral infarction. This review proposes cerebral infarction be defined as brain or retinal cell death due to prolonged ischemia. This definition categorizes both pannecrosis and neuronal dropout ("complete" and "incomplete" infarcts in classic neuropathologic terminology) as cerebral infarcts. Making the presence of any neuronal or glial cell death essential yields a definition of cerebral infarction that has high relevance to patients, physicians, and policymakers; is more easily applied in clinical practice; fosters action in acute care; harmonizes with myocardial ischemia classification; and focuses diagnostic evaluation on the cause of brain ischemia and the occurrence of end organ injury. The term cerebral infarction should be used when there is evidence of brain or retinal cell death due to cerebral ischemia.

  13. Seawater circulating system in an aquaculture laboratory

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A.; Ingole, B.S.; Parulekar, A.H.

    The note gives an account, for the first time in India, of an Aquaculture Laboratory with open type seawater circulating system developed at the National Institute of Oceanography, Goa, India. Besides describing the details of the system...

  14. Western Indian Ocean circulation and climate variability on different time scales. A study based on stable oxygen and carbon isotopes, benthic foraminiferal assemblages and Mg/Ca paleothermometry

    Energy Technology Data Exchange (ETDEWEB)

    Romahn, Sarah

    2014-08-19

    In order to understand the Earth's climate evolution it is crucial to evaluate the role of low-latitude oceans in the global climate system, as they are connected to both hemispheres via atmospheric and oceanic circulation and thus hold the potential to disentangle the asynchronicity of short-term Pleistocene climate variability. However, the potential of low latitude oceans to respond to and force large-scale changes of the climate system is still debated. The aim of this thesis is to examine and to understand the causal relationship of both atmospheric and oceanic changes in the tropical western Indian Ocean on centennial-, millennial and glacial-interglacial timescales. For this purpose I investigated stable oxygen and carbon isotope compositions of both planktic and benthic foraminiferal tests, Mg/Ca ratios of planktic foraminiferal tests as well as benthic foraminiferal assemblages and sedimentary geochemical parameters on two sediment cores (GeoB12615-4, 446 m and GeoB12616-4, 1449 m) from the continental slope off Tanzania, East Africa.

  15. Routine clinical use of circulating tumor cells for diagnosis of mutations and chromosomal rearrangements in non-small cell lung cancer-ready for prime-time?

    Science.gov (United States)

    Pailler, Emma; Faugeroux, Vincent; Oulhen, Marianne; Catelain, Cyril; Farace, Françoise

    2017-08-01

    In non-small cell lung cancer (NSCLC), diagnosis of predictive biomarkers for targeted therapies is currently done in small tumor biopsies. However, tumor biopsies can be invasive, in some cases associated with risk, and tissue adequacy, both in terms of quantity and quality is often insufficient. The development of efficient and non-invasive methods to identify genetic alterations is a key challenge which circulating tumor cells (CTCs) have the potential to be exploited for. CTCs are extremely rare and phenotypically diverse, two characteristics that impose technical challenges and impact the success of robust molecular analysis. Here we introduce the clinical needs in this disease that mainly consist of the diagnosis of epidermal growth factor receptor ( EGFR ) activating alterations and anaplastic lymphoma kinase ( ALK ) rearrangement. We present the proof-of-concept studies that explore the detection of these genetic alterations in CTCs from NSCLC patients. Finally, we discuss steps that are still required before CTCs are routinely used for diagnosis of EGFR -mutations and ALK -rearrangements in this disease.

  16. Western Indian Ocean circulation and climate variability on different time scales. A study based on stable oxygen and carbon isotopes, benthic foraminiferal assemblages and Mg/Ca paleothermometry

    International Nuclear Information System (INIS)

    Romahn, Sarah

    2014-01-01

    In order to understand the Earth's climate evolution it is crucial to evaluate the role of low-latitude oceans in the global climate system, as they are connected to both hemispheres via atmospheric and oceanic circulation and thus hold the potential to disentangle the asynchronicity of short-term Pleistocene climate variability. However, the potential of low latitude oceans to respond to and force large-scale changes of the climate system is still debated. The aim of this thesis is to examine and to understand the causal relationship of both atmospheric and oceanic changes in the tropical western Indian Ocean on centennial-, millennial and glacial-interglacial timescales. For this purpose I investigated stable oxygen and carbon isotope compositions of both planktic and benthic foraminiferal tests, Mg/Ca ratios of planktic foraminiferal tests as well as benthic foraminiferal assemblages and sedimentary geochemical parameters on two sediment cores (GeoB12615-4, 446 m and GeoB12616-4, 1449 m) from the continental slope off Tanzania, East Africa.

  17. Seasonal overturning circulation in the Red Sea: 2. Winter circulation

    KAUST Repository

    Yao, Fengchao; Hoteit, Ibrahim; Pratt, Lawrence J.; Bower, Amy S.; Kö hl, Armin; Gopalakrishnan, Ganesh; Rivas, David

    2014-01-01

    The shallow winter overturning circulation in the Red Sea is studied using a 50 year high-resolution MITgcm (MIT general circulation model) simulation with realistic atmospheric forcing. The overturning circulation for a typical year, represented

  18. Comprehensive Overview of Contemporary Management Strategies for Cerebral Aneurysms.

    Science.gov (United States)

    Manhas, Amitoz; Nimjee, Shahid M; Agrawal, Abhishek; Zhang, Jonathan; Diaz, Orlando; Zomorodi, Ali R; Smith, Tony; Powers, Ciarán J; Sauvageau, Eric; Klucznik, Richard P; Ferrell, Andrew; Golshani, Kiarash; Stieg, Philip E; Britz, Gavin W

    2015-10-01

    Aneurysmal subarachnoid hemorrhage (SAH) remains an important health issue in the United States. Despite recent improvements in the diagnosis and treatment of cerebral aneurysms, the mortality rate following aneurysm rupture. In those patients who survive, up to 50% are left severely disabled. The goal of preventing the hemorrhage or re-hemorrhage can only be achieved by successfully excluding the aneurysm from the circulation. This article is a comprehensive review by contemporary vascular neurosurgeons and interventional neuroradiolgists on the modern management of cerebral aneurysms. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Relationship between availability of the collateral circulation and ischemic time for myocardial viability in patients with acute myocardial infarction. Assessment by technetium-99m tetrofosmin single photon emission computed tomography

    International Nuclear Information System (INIS)

    Kanamori, Norio; Kondo, Makoto; Fukuoka, Yoshitomo; Higuchi, Hirokazu; Kubota, Tomoyuki; Matsuoka, Ryota; Araki, Makoto; Tanio, Hitoshi; Doyama, Kiyoshi

    2007-01-01

    Myocardial accumulation before reperfusion therapy of a radioactive tracer in the completely occluded region, conceivably reflects the viability of myocytes and degree of collateral circulation. To confirm this, the present study examined the relationship in the title. Subjects were 33 patients (F 7, M 26; average age 65 y) of the first 1-branch acute myocardial infarction and of TIMI (thrombolysis in myocardial infarction trial) grade 0 who recovered to TIMI 3 within 12 hr after attack: 99m Tc-tetrofosmin, 740 MBq, was intravenously injected before reperfusion and just after which, SPECT imaging (TF-SPECT) was conducted with Toshiba E. CAM, and regional severity score index (RSSI) (0-3) was calculated. About 1 week later, to see the myocardial viability in the chronic phase, GITl (Glucose-Insulin- 201 Tl) (111 MBq) SPECT was performed 30 min after its injection to calculate RSSI as above, and the echocardiography with ALOKA Pro Sound SSD-4000 or SIEMENS Acuson SEQUOIA C256 was done to calculate the regional wall motion score index (RWMSI) (0-4). RWMSI was found significantly correlated with TF-RSSI, the group with the better collateral circulation (TF-RSSI, 1.9 or less) exhibited significantly lower GITl-RSSI and RWMSI, and correlation between the ischemic time and neither TF-RSSI, GITl-RSSI nor RWMSI was found. Thus under these conditions, the development of collateral vessels was found to have potential protective effects on myocardium independently on the ischemic time. (T.I.)

  20. Behcet's disease with cerebral vasculitis

    International Nuclear Information System (INIS)

    Scardamaglia, L.; Desmond, P.M.; Gonzales, M.F.; Bendrups, A.; Brodtmann, A.

    2001-01-01

    The case presented illustrates the diagnostic dilemma off neurological involvement in Behcet's disease and other inflammatory diseases. 'Psychiatric' symptoms were present for 2 years without abnormalities on SPECT or MRI and without CSF pleocytosis. Even at the time of fitting, no CSF abnormalities were observed. The preceding psychiatric presentations may have been due to cerebral vasculitis that was exacerbated by withdrawal of steroids. Magnetic resonance imaging is currently the most sensitive imaging modality. Lesions are usually in the brainstem, cerebellum, basal ganglia region or periventricular white matter, and the pons and the mesencephalon are commonly affected. In our patient there was no diencephalic or brainstem involvement. The inflammatory process can appear as a very large lesion, with gadolinium enhancement and significant mass effect, as in our patient. Brain magnetic resonance imaging. Postgadolinium-diethylenetriamine pentaacetic acid, axial image shows two large lesions in the right frontal lobe, with the larger, posterior lesion demonstrating vivid ring enhancement. A central nodule is isodense, with the cerebral white matter within the larger lesion. Surrounding low T 1 signal involves the hemispheric white matter without cortical extension and is consistent with vasogenic oedema. Minor mass effect is demonstrated with bowing of the anterior falx cerebri to the left. Biopsy shows prominent fibrinoid necrosis in small calibre postcapillary venules and cerebral white matter. There are surrounding acute and chronic inflammatory cells and nuclear debris, consistent with vasculitis

  1. Cerebral Palsy (For Parents)

    Science.gov (United States)

    ... Going to an Occupational Therapist Scoliosis In the Band: Jens' Story Cerebral ... KidsHealth® is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995- ...

  2. Cerebral Contusions and Lacerations

    Science.gov (United States)

    ... Contusions and Lacerations Concussion Diffuse Axonal Injury Intracranial Hematomas Skull Fracture Sports-Related Concussion Cerebral contusions are ... Contusions and Lacerations Concussion Diffuse Axonal Injury Intracranial Hematomas Skull Fracture Sports-Related Concussion NOTE: This is ...

  3. Cerebral cartography and connectomics

    OpenAIRE

    Sporns, Olaf

    2015-01-01

    Cerebral cartography and connectomics pursue similar goals in attempting to create maps that can inform our understanding of the structural and functional organization of the cortex. Connectome maps explicitly aim at representing the brain as a complex network, a collection of nodes and their interconnecting edges. This article reflects on some of the challenges that currently arise in the intersection of cerebral cartography and connectomics. Principal challenges concern the temporal dynamic...

  4. Time course of changes in cerebral blood flow velocity after tourniquet deflation in patients with diabetes mellitus or previous stroke under sevoflurane anesthesia.

    Science.gov (United States)

    Hinohara, Hiroshi; Kadoi, Yuji; Takahashi, Kenichiro; Saito, Shigeru; Kawauchi, Chikara; Mizutani, Akio

    2011-06-01

    We observed an increase in mean middle cerebral artery blood flow velocity (V(mca)) after tourniquet deflation during orthopedic surgery under sevoflurane anesthesia in patients with diabetes mellitus or previous stroke. Eight controls, seven insulin-treated diabetic patients, and eight previous stroke patients were studied. Arterial blood pressure, heart rate, V(mca), arterial blood gases, and plasma lactate levels were measured every minute for 10 min after tourniquet release in all patients. V(mca) was measured using a transcranial Doppler probe. V(mca) in all three groups increased after tourniquet deflation, the increase lasting for 4 or 5 min. However, the degree of increase in V(mca) in the diabetic patients was smaller than that in the other two groups after tourniquet deflation (at 2 min after tourniquet deflation: control 58.5 ± 3.3, previous stroke 58.4 ± 4.6, diabetes 51.7 ± 2.3; P < 0.05 compared with the other two groups). In conclusion, the degree of increase in V (mca) in diabetic patients is smaller than that in controls and patients with previous stroke.

  5. Development of tailored real-time RT-PCR assays for the detection and differentiation of serotype O, A and Asia-1 foot-and-mouth disease virus lineages circulating in the Middle East.

    Science.gov (United States)

    Reid, Scott M; Mioulet, Valerie; Knowles, Nick J; Shirazi, Nazeem; Belsham, Graham J; King, Donald P

    2014-10-01

    Rapid and accurate diagnosis is essential for effective control of foot-and-mouth disease (FMD). In countries where FMD is endemic, identification of the serotypes of the causative virus strains is important for vaccine selection and tracing the source of outbreaks. In this study, real-time reverse transcription polymerase chain reaction (rRT-PCR) assays using primer/probe sets designed from the VP1 coding region of the virus genomes were developed for the specific detection of serotype O, A and Asia-1 FMD viruses (FMDVs) circulating in the Middle East. These assays were evaluated using representative field samples of serotype O strains belonging exclusively to the PanAsia-2 lineage, serotype A strains of the Iran-05 lineage and serotype Asia-1 viruses from three relevant sub-groups. When RNA extracted from archival and contemporary field strains was tested using one- or two-step rRT-PCR assays, all three primer/probe sets detected the RNA from homotypic viruses and no cross-reactivity was observed with heterotypic viruses. Similar results were obtained using both single- and multiplex assay formats. Using plasmid standards, the minimum detection level of these tests was found to be lower than two copies. The results illustrate the potential of tailored rRT-PCR tools for the detection and categorization of viruses circulating in the Middle East belonging to distinct subgroups of serotypes O, A and Asia-1. These assays can also overcome the problem of serotyping samples which are found positive by the generic rRT-PCR diagnostic assays but negative by virus isolation and antigen-detection ELISA which would otherwise have to be serotyped by nucleotide sequencing. A similar approach could be used to develop serotyping assays for FMDV strains circulating in other regions of the world. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  6. Nanomedicine in cerebral palsy

    Science.gov (United States)

    Balakrishnan, Bindu; Nance, Elizabeth; Johnston, Michael V; Kannan, Rangaramanujam; Kannan, Sujatha

    2013-01-01

    Cerebral palsy is a chronic childhood disorder that can have diverse etiologies. Injury to the developing brain that occurs either in utero or soon after birth can result in the motor, sensory, and cognitive deficits seen in cerebral palsy. Although the etiologies for cerebral palsy are variable, neuroinflammation plays a key role in the pathophysiology of the brain injury irrespective of the etiology. Currently, there is no effective cure for cerebral palsy. Nanomedicine offers a new frontier in the development of therapies for prevention and treatment of brain injury resulting in cerebral palsy. Nanomaterials such as dendrimers provide opportunities for the targeted delivery of multiple drugs that can mitigate several pathways involved in injury and can be delivered specifically to the cells that are responsible for neuroinflammation and injury. These materials also offer the opportunity to deliver agents that would promote repair and regeneration in the brain, resulting not only in attenuation of injury, but also enabling normal growth. In this review, the current advances in nanotechnology for treatment of brain injury are discussed with specific relevance to cerebral palsy. Future directions that would facilitate clinical translation in neonates and children are also addressed. PMID:24204146

  7. Hemodynamics in the cerebral cortex and basal ganglia

    International Nuclear Information System (INIS)

    Yamaguchi, Shinya; Fukuyama, Hidenao; Yamauchi, Hiroshi; Kimura, Jun

    1991-01-01

    We examined ten healthy volunteers using positron emission tomography (PET) in order to elucidate regional changes and correlations in the cerebral circulation and oxygen metabolism. We also studied eight lacunar stroke patients so as to disclose the influences of vascular risk factors and aging on the cerebral blood flow and metabolism. We can conclude from our result as follows: (1) Cerebral blood volume (CBV) was minimum in the basal ganglia and cerebral blood flow (CBF)/CBV ratio was higher than that of cerebral cortex in healthy volunteers; (2) CBF of gray matter in healthy volunteers correlated with CBV and cerebral metabolic rate of oxygen where oxygen extraction fraction inversely correlated with CBF, CBV, and CBF/CBV; and (3) the basal ganglia CBF/CBV ratio in lacunar stroke patients was lower than that of healthy volunteers. These findings suggested that the perfusion pressure in the basal ganglia was so high in the normal condition than the angionecrosis or occlusion in the perforating arteries would be induced, especially in the aged and hypertensive patients. (author)

  8. Recovery of cerebral blood flow in unilateral chronic subdural hematoma. The correlation with cerebral re-expansion in elders

    International Nuclear Information System (INIS)

    Nemoto, Akio

    2003-01-01

    CT and SPECT were used to investigate the relationship between cerebral re-expansion and changes in cerebral blood flow underneath hematoma in elderly patients after surgery for chronic unilateral subdural hematoma. I studied 22 patients with mild hematoma, aged 43 to 82 years (mean 67 years). The patients were placed in either Group A (under 70 years) or Group B (70 years or over) to observe postoperative changes. CT and SPECT examinations were conducted before surgery and 1, 7 and 30 days after surgery, 4 times in total. Cerebral re-expansion was represented by the re-expansion rate (PER) comparing the pre- and postoperative thickness of the maximal hematoma in CT images. The rate of cerebral re-expansion was slowed in Group B (p<0.01). Cerebral re-expansion was characterized by biphasic, rapid or gradual re-expansion on postoperative day 1 with a significant difference between groups (p<0.01). Before surgery, cerebral blood flow on the affected side correlated with age (p<0.01), thougn blood flow was diminished in both groups. After surgery, cerebral blood flow on the affected side exceeded that on the unaffected side in Group A and transiently increased on postoperative day 1. Cerebral blood flow improved after surgery in both groups, with a significant difference in those changes over time (p<0.01). In both groups, cerebral re-expansion on postoperative days 7 and 30 correlated with cerebral blood flow on the affected side (p<0.05). The present results suggest that improvement in cerebral blood flow on the affected side is delayed in elderly patients, due to slower postoperative cerebral re-expansion. (author)

  9. Cerebral palsy and congenital malformations

    DEFF Research Database (Denmark)

    Garne, Ester; Dolk, Helen; Krägeloh-Mann, Inge

    2007-01-01

    AIM: To determine the proportion of children with cerebral palsy (CP) who have cerebral and non-cerebral congenital malformations. METHODS: Data from 11 CP registries contributing to the European Cerebral Palsy Database (SCPE), for children born in the period 1976-1996. The malformations were...... classified as recognized syndromes, chromosomal anomalies, cerebral malformations or non-cerebral malformations. Prevalence of malformations was compared to published data on livebirths from a European database of congenital malformations (EUROCAT). RESULTS: Overall 547 out of 4584 children (11.9%) with CP...... were reported to have a congenital malformation. The majority (8.6% of all children) were diagnosed with a cerebral malformation. The most frequent types of cerebral malformations were microcephaly and hydrocephaly. Non-cerebral malformations were present in 97 CP children and in further 14 CP children...

  10. Quality of Arithmetic Education for Children with Cerebral Palsy

    Science.gov (United States)

    Jenks, Kathleen M.; de Moor, Jan; van Lieshout, Ernest C. D. M.; Withagen, Floortje

    2010-01-01

    The aim of this exploratory study was to investigate the quality of arithmetic education for children with cerebral palsy. The use of individual educational plans, amount of arithmetic instruction time, arithmetic instructional grouping, and type of arithmetic teaching method were explored in three groups: children with cerebral palsy (CP) in…

  11. Modelling of impaired cerebral blood flow due to gaseous emboli

    International Nuclear Information System (INIS)

    Hague, J P; Banahan, C; Chung, E M L

    2013-01-01

    Bubbles introduced to the arterial circulation during invasive medical procedures can have devastating consequences for brain function but their effects are currently difficult to quantify. Here we present a Monte Carlo simulation investigating the impact of gas bubbles on cerebral blood flow. For the first time, this model includes realistic adhesion forces, bubble deformation, fluid dynamical considerations, and bubble dissolution. This allows investigation of the effects of buoyancy, solubility, and blood pressure on embolus clearance. Our results illustrate that blockages depend on several factors, including the number and size distribution of incident emboli, dissolution time and blood pressure. We found it essential to model the deformation of bubbles to avoid overestimation of arterial obstruction. Incorporation of buoyancy effects within our model slightly reduced the overall level of obstruction but did not decrease embolus clearance times. We found that higher blood pressures generate lower levels of obstruction and improve embolus clearance. Finally, we demonstrate the effects of gas solubility and discuss potential clinical applications of the model. (paper)

  12. Studies of Ocean Predictability at Decade to Century Time Scales Using a Global Ocean General Circulation Model in a Parallel Computing Environment; FINAL

    International Nuclear Information System (INIS)

    Barnett, T.P.

    1998-01-01

    The objectives of this report are to determine the structure of oceanic natural variability at time scales of decades to centuries, characterize the physical mechanisms responsible for the variability; determine the relative importance of heat, fresh water, and moment fluxes on the variability; determine the predictability of the variability on these times scales

  13. Correlations of circulating peptide YY and ghrelin with body weight, rate of weight gain, and time required to achieve the recommended daily intake in preterm infants.

    Science.gov (United States)

    Chen, XiaFang; Du, XueLiang; Zhu, JianXing; Xie, LiJuan; Zhang, YongJun; He, ZhenJuan

    2012-07-01

    The objective was to elucidate the relationships between serum concentrations of the gut hormone peptide YY (PYY) and ghrelin and growth development in infants for potential application to the clinical observation index. Serum concentrations of PYY and ghrelin were measured using radioimmunoassay from samples collected at the clinic. For each patient, gestational age, birth weight, time required to return to birth weight, rate of weight gain, time required to achieve recommended daily intake (RDI) standards, time required for full-gastric feeding, duration of hospitalization, and time of administration of total parenteral nutrition were recorded. Serum PYY and ghrelin concentrations were significantly higher in the preterm group (N = 20) than in the full-term group (N = 20; P weight, and the degree of correlation varied with age. Serum ghrelin concentration correlated negatively with birth weight and positively with the time required to achieve RDI (P newborns and to determine the usefulness of measuring these hormones in clinical practice.

  14. Long-term evolution of cerebral hemodynamics after brain irradiation in the rat

    International Nuclear Information System (INIS)

    Keyeux, A.; Ochrymowicz-Bemelmans, D.

    1985-01-01

    Long-term evolution of radioisotope indices, evaluating respectively the cerebral blood flow (CBF), the cerebral blood volume (CBV) and the cephalic specific distribution space of iodoantipyrine (ΔIAP) of rat, was studied after brain irradiation at 20 Gy. Radioinduced hemodynamic alterations evidenced by this approach are biphasic and support the prominent role of circulation impairment in the genesis of delayed brain radionecrosis [fr

  15. Pathological review of late cerebral radionecrosis

    International Nuclear Information System (INIS)

    Yoshii, Yoshihiko

    2008-01-01

    Late cerebral radionecrosis may be considered to be a specific chronic inflammatory response, although it is unknown whether the initial damage by brain irradiation is to an endothelial cell or a glial cell. I discuss the pathological specificity of late cerebral radionecrosis by studying the published literature and a case that I experienced. In late cerebral radionecrosis, there are typical coagulation necrosis areas containing fibrinoid necrosis with occlusion of the lumina and poorly active inflammatory areas with many inflammatory ghost cells, focal perivascular lymphocytes, hyalinized vessels, and telangiectatic vascularization near and in the necrotic tissue, and more active inflammatory areas formed as a partial rim of the reactive zone by perivascular lymphocytes, much vascularization, and glial fibrillary acidic protein (GFAP)-positive astrocytes at the corticomedullary border adjacent to necrotic tissue in the white matter. It is difficult to believe that coagulation necrosis occurs without first disordering the vascular endothelial cells because fibrinoid necrosis is a main feature and a diffusely multiple lesion in late cerebral radionecrosis. Because various histological findings do develop, progress, and extend sporadically at different areas and times in the irradiated field of the brain for a long time after radiation, uncontrolled chronic inflammation containing various cytokine secretions may also play a key role in progression of this radionecrosis. Evaluation of the mechanism of the development/aggravation of late cerebral radionecrosis requires a further study for abnormal cytokine secretions and aberrant inflammatory reactions. (author)

  16. Nanomedicine in cerebral palsy

    Directory of Open Access Journals (Sweden)

    Balakrishnan B

    2013-11-01

    Full Text Available Bindu Balakrishnan,1 Elizabeth Nance,1 Michael V Johnston,2 Rangaramanujam Kannan,3 Sujatha Kannan1 1Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University; Baltimore, MD, USA; 2Department of Neurology and Pediatrics, Kennedy Krieger Institute, Baltimore, MD, USA; 3Department of Ophthalmology, Center for Nanomedicine, Johns Hopkins University, Baltimore, MD, USA Abstract: Cerebral palsy is a chronic childhood disorder that can have diverse etiologies. Injury to the developing brain that occurs either in utero or soon after birth can result in the motor, sensory, and cognitive deficits seen in cerebral palsy. Although the etiologies for cerebral palsy are variable, neuroinflammation plays a key role in the pathophysiology of the brain injury irrespective of the etiology. Currently, there is no effective cure for cerebral palsy. Nanomedicine offers a new frontier in the development of therapies for prevention and treatment of brain injury resulting in cerebral palsy. Nanomaterials such as dendrimers provide opportunities for the targeted delivery of multiple drugs that can mitigate several pathways involved in injury and can be delivered specifically to the cells that are responsible for neuroinflammation and injury. These materials also offer the opportunity to deliver agents that would promote repair and regeneration in the brain, resulting not only in attenuation of injury, but also enabling normal growth. In this review, the current advances in nanotechnology for treatment of brain injury are discussed with specific relevance to cerebral palsy. Future directions that would facilitate clinical translation in neonates and children are also addressed. Keywords: dendrimer, cerebral palsy, neuroinflammation, nanoparticle, neonatal brain injury, G4OH-PAMAM

  17. Relationship Between Cerebral Oxygenation and Hemodynamic and Oxygen Transport Parameters in Surgery for Acquired Heart Diseases

    Directory of Open Access Journals (Sweden)

    A. I. Lenkin

    2012-01-01

    Full Text Available Objective: to evaluate the relationship between cerebral oxygenation and hemodynamic and oxygen transport parameters in surgical correction of concomitant acquired heart diseases. Subjects and methods. Informed consent was received from 40 patients who required surgery because of concomitant (two or more acquired heart defects. During procedure, perioperative monitoring of oxygen transport and cerebral oxygenation was performed with the aid of PiCCO2 monitor (Pulsion Medical Systems, Germany and a Fore-Sight cerebral oximeter (CASMED, USA. Anesthesia was maintained with propofol and fen-tanyl, by monitoring the depth of anesthesia. Early postoperative intensive therapy was based on the protocol for early targeted correction of hemodynamic disorders. Oxygen transport and cerebral oxygenation parameters were estimated intraopera-tively and within 24 postoperative hours. A statistical analysis including evaluation of Spearman correlations was performed with the aid of SPSS 15.0. Results. During perfusion, there was a relationship between cerebral oximetry values and hemat-ocrit levels, and oxygen partial pressure in the venous blood. Furthermore, a negative correlation between cerebral oximetry values and blood lactate levels was found 30 minutes after initiation of extracorporeal circulation (EC. During the study, there was a positive correlation between cerebral oxygenation and values of cardiac index, central venous saturation, and oxygen delivery index. There was a negative relationship between cerebral oxygenation and extravascular lung water at the beginning of surgery and a correlation between cerebral oximetry values and oxygenation index by the end of the first 24 postoperative hours. Conclusion. The cerebral oxygenation values correlate -with the main determinants of oxygen transport during EC and after cardiac surgical procedures. Cerebral oximetry may be used in early targeted therapy for the surgical correction of acquired combined

  18. Monitoring of cerebral haemodynamics in newborn infants

    DEFF Research Database (Denmark)

    Liem, K Djien; Greisen, Gorm

    2010-01-01

    The most important cerebrovascular injuries in newborn infants, particularly in preterm infants, are cerebral haemorrhage and ischemic injury. The typical cerebral vascular anatomy and the disturbance of cerebral haemodynamics play important roles in the pathophysiology. The term 'cerebral haemod...

  19. Dynamic Cerebral Autoregulation in Pregnancy and the Risk of Preeclampsia

    DEFF Research Database (Denmark)

    Janzarik, Wibke G; Ehlers, Elena; Ehmann, Renata

    2014-01-01

    Preeclampsia may affect severely the cerebral circulation leading to impairment of cerebral autoregulation, edema, and ischemia. It is not known whether impaired autoregulation occurs before the clinical onset of preeclampsia, and whether this can predict the occurrence of preeclampsia. Seventy......) of respiratory-induced 0.1 Hz hemodynamic oscillations. Uterine artery ultrasound was performed to search for a notch sign as an early marker of general endothelial dysfunction. All women were followed up until 6 weeks after delivery for the occurrence of preeclampsia. The autoregulation parameter gain did...... not differ between pregnant and nonpregnant women. Phase was slightly but significantly higher in pregnant women, indicating better DCA. Women with a notch sign did not show altered DCA. A history of preeclampsia during a previous pregnancy was associated with lower phase in middle cerebral artery...

  20. Transient cerebral hypoperfusion and hypertensive events during atrial fibrillation: a plausible mechanism for cognitive impairment.

    Science.gov (United States)

    Anselmino, Matteo; Scarsoglio, Stefania; Saglietto, Andrea; Gaita, Fiorenzo; Ridolfi, Luca

    2016-06-23

    Atrial fibrillation (AF) is associated with an increased risk of dementia and cognitive decline, independent of strokes. Several mechanisms have been proposed to explain this association, but altered cerebral blood flow dynamics during AF has been poorly investigated: in particular, it is unknown how AF influences hemodynamic parameters of the distal cerebral circulation, at the arteriolar and capillary level. Two coupled lumped-parameter models (systemic and cerebrovascular circulations, respectively) were here used to simulate sinus rhythm (SR) and AF. For each simulation 5000 cardiac cycles were analyzed and cerebral hemodynamic parameters were calculated. With respect to SR, AF triggered a higher variability of the cerebral hemodynamic variables which increases proceeding towards the distal circulation, reaching the maximum extent at the arteriolar and capillary levels. This variability led to critical cerebral hemodynamic events of excessive pressure or reduced blood flow: 303 hypoperfusions occurred at the arteriolar level, while 387 hypertensive events occurred at the capillary level during AF. By contrast, neither hypoperfusions nor hypertensive events occurred during SR. Thus, the impact of AF per se on cerebral hemodynamics candidates as a relevant mechanism into the genesis of AF-related cognitive impairment/dementia.

  1. Endothelial glycocalyx on brain endothelial cells is lost in experimental cerebral malaria

    DEFF Research Database (Denmark)

    Hempel, Casper; Hyttel, Poul; Kurtzhals, Jørgen Al

    2014-01-01

    We hypothesized that the glycocalyx, which is important for endothelial integrity, is lost in severe malaria. C57BL/6 mice were infected with Plasmodium berghei ANKA, resulting in cerebral malaria, or P. chabaudi AS, resulting in uncomplicated malaria. We visualized the glycocalyx with transmission...... electron microscopy and measured circulating glycosaminoglycans by dot blot and ELISA. The glycocalyx was degraded in brain vasculature in cerebral and to a lesser degree uncomplicated malaria. It was affected on both intact and apoptotic endothelial cells. Circulating glycosaminoglycan levels suggested...

  2. Fatal Cerebral Air Embolism: A Case Series and Literature Review

    Directory of Open Access Journals (Sweden)

    Rashmi Mishra

    2016-01-01

    Full Text Available Cerebral air embolism (CAE is an infrequently reported complication of routine medical procedures. We present two cases of CAE. The first patient was a 55-year-old male presenting with vomiting and loss of consciousness one day after his hemodialysis session. Physical exam was significant for hypotension and hypoxia with no focal neurologic deficits. Computed tomography (CT scan of head showed gas in cerebral venous circulation. The patient did not undergo any procedures prior to presentation, and his last hemodialysis session was uneventful. Retrograde rise of venous air to the cerebral circulation was the likely mechanism for venous CAE. The second patient was a 46-year-old female presenting with fever, shortness of breath, and hematemesis. She was febrile, tachypneic, and tachycardic and required intubation and mechanical ventilation. An orogastric tube inserted drained 2500 mL of bright red blood. Flexible laryngoscopy and esophagogastroduodenoscopy were performed. She also underwent central venous catheter placement. CT scan of head performed the next day due to absent brain stem reflexes revealed intravascular air within cerebral arteries. A transthoracic echocardiogram with bubble study ruled out patent foramen ovale. The patient had a paradoxical CAE in the absence of a patent foramen ovale.

  3. An investigation of cerebral magnetic resonance angiography, 5

    International Nuclear Information System (INIS)

    Takeda, Sadanori; Sadamoto, Kazuhiko; Ohue, Shiro; Todo, Hirooki; Sakaki, Saburo.

    1992-01-01

    A number of studies of MR angiography (MRA) as a noninvasive screening method for vascular diseases have been reported recently. Almost all of them were investigated using high tesla magnets (1.5 tesla). We have been investigating three-dimensional MRA using a medium tesla (0.5 tesla) system (HITACHI G-50). The purpose of this study is to evaluate the usefulness of 3-D MRA for the screening of cerebral aneurysms. Twenty patients with 25 cerebral aneurysms were included in this study. The sizes of the aneurysms ranged from 2 to 35 mm. Twenty-three aneurysms were located on the anterior circulation, and 2 on the posterior circulation. MR angiography was performed with a gradient-echo sequence at a TR of 50 msec, a TE of 16 msec, and a flip angle of 25 degrees. The imaging volumes ranged in thickness from 48 to 64 mm, with 32 partitions. We used a sequence-subtraction technique composed of rephased and dephased sequences; it provides a good visualization of the main cerebral arteries. Cerebral aneurysms were detected on 3-D MRA in 23 lesions (92%). We consider that 0.5 tesla 3-D MRA could be useful for the screening of nonruptured aneurysms. (author)

  4. Subarachnoid Hemorrhage Severely Impairs Brain Parenchymal Cerebrospinal Fluid Circulation in Nonhuman Primate.

    Science.gov (United States)

    Goulay, Romain; Flament, Julien; Gauberti, Maxime; Naveau, Michael; Pasquet, Nolwenn; Gakuba, Clement; Emery, Evelyne; Hantraye, Philippe; Vivien, Denis; Aron-Badin, Romina; Gaberel, Thomas

    2017-08-01

    Subarachnoid hemorrhage (SAH) is a devastating form of stroke with neurological outcomes dependent on the occurrence of delayed cerebral ischemia. It has been shown in rodents that some of the mechanisms leading to delayed cerebral ischemia are related to a decreased circulation of the cerebrospinal fluid (CSF) within the brain parenchyma. Here, we evaluated the cerebral circulation of the CSF in a nonhuman primate in physiological condition and after SAH. We first evaluated in physiological condition the circulation of the brain CSF in Macaca facicularis , using magnetic resonance imaging of the temporal DOTA-Gd distribution after its injection into the CSF. Then, animals were subjected to a minimally invasive SAH before an MRI evaluation of the impact of SAH on the brain parenchymal CSF circulation. We first demonstrate that the CSF actively penetrates the brain parenchyma. Two hours after injection, almost the entire brain is labeled by DOTA-Gd. We also show that our model of SAH in nonhuman primate displays the characteristics of SAH in humans and leads to a dramatic impairment of the brain parenchymal circulation of the CSF. The CSF actively penetrates within the brain parenchyma in the gyrencephalic brain, as described for the glymphatic system in rodent. This parenchymal CSF circulation is severely impaired by SAH. © 2017 American Heart Association, Inc.

  5. Development and Characterization of Probe-Based Real Time Quantitative RT-PCR Assays for Detection and Serotyping of Foot-And-Mouth Disease Viruses Circulating in West Eurasia

    DEFF Research Database (Denmark)

    Jamal, Syed M.; Belsham, Graham

    2015-01-01

    Asia,A-Iran05 and Asia-1 (Group-II and Group-VII (Sindh-08)). In addition, field samples from Iran and Bulgaria, containing FMDVs belonging to the O-PanAsiaANT-10 subline-agewere also tested. Each of the three primer/probe sets was designed to be specific for just one of the serotypes O, A and Asia-1 of FMDV....... Due to the heterogeneity of FMD viruses (FMDVs) in different parts of the world, region specific diagnostic tests are required. In this study, hydrolysableprobe-based real time reverse transcription quantitative polymerase chain reaction (RTqPCR) assays were developed for specific detection...... and serotyping of the FMDVs currently circulating in West Eurasia. These assays were evaluated, in parallel with pan-FMDV diagnosticassays and earlier serotype-specific assays, using field samples originating from Pakistan and Afghanistan containing FMD viruses belonging to different sublineages of OPan...

  6. Upper limit of cerebral blood flow autoregulation in experimental renovascular hypertension in the baboon

    DEFF Research Database (Denmark)

    Strandgaard, S; Jones, J V; MacKenzie, E T

    1975-01-01

    The effect of arterial hypertension on cerebral blood flow was studied by the intracarotid 133Xe clearance method in baboons. The arterial blood pressure was raised in gradual steps with angiotensin. Baboons with renal hypertension of 8-12 weeks duration were studied along with normotensive baboons....... In initially normotensive baboons, cerebral blood flow remained constant until the mean arterial blood pressure had risen to the range of 140 to 154 mm Hg; thereafter cerebral blood flow increased with each rise in mean arterial blood pressure. In the chronically hypertensive baboons, cerebral blood flow...... remained constant until the mean arterial blood pressure had been elevated to the range of 155 to 169 mm Hg. Thus, in chronic hypertension it appears that there are adaptive changes in the cerebral circulation which may help to protect the brain from further increases in arterial blood pressure....

  7. Cerebral Pathophysiology in Extracorporeal Membrane Oxygenation: Pitfalls in Daily Clinical Management

    Directory of Open Access Journals (Sweden)

    Syed Omar Kazmi

    2018-01-01

    Full Text Available Extracorporeal membrane oxygenation (ECMO is a life-saving technique that is widely being used in centers throughout the world. However, there is a paucity of literature surrounding the mechanisms affecting cerebral physiology while on ECMO. Studies have shown alterations in cerebral blood flow characteristics and subsequently autoregulation. Furthermore, the mechanical aspects of the ECMO circuit itself may affect cerebral circulation. The nature of these physiological/pathophysiological changes can lead to profound neurological complications. This review aims at describing the changes to normal cerebral autoregulation during ECMO, illustrating the various neuromonitoring tools available to assess markers of cerebral autoregulation, and finally discussing potential neurological complications that are associated with ECMO.

  8. SpaceX Dragon Air Circulation System

    Science.gov (United States)

    Hernandez, Brenda; Piatrovich, Siarhei; Prina, Mauro

    2011-01-01

    The Dragon capsule is a reusable vehicle being developed by Space Exploration Technologies (SpaceX) that will provide commercial cargo transportation to the International Space Station (ISS). Dragon is designed to be a habitable module while it is berthed to ISS. As such, the Dragon Environmental Control System (ECS) consists of pressure control and pressure equalization, air sampling, fire detection, illumination, and an air circulation system. The air circulation system prevents pockets of stagnant air in Dragon that can be hazardous to the ISS crew. In addition, through the inter-module duct, the air circulation system provides fresh air from ISS into Dragon. To utilize the maximum volume of Dragon for cargo packaging, the Dragon ECS air circulation system is designed around cargo rack optimization. At the same time, the air circulation system is designed to meet the National Aeronautics Space Administration (NASA) inter-module and intra-module ventilation requirements and acoustic requirements. A flight like configuration of the Dragon capsule including the air circulation system was recently assembled for testing to assess the design for inter-module and intra-module ventilation and acoustics. The testing included the Dragon capsule, and flight configuration in the pressure section with cargo racks, lockers, all of the air circulation components, and acoustic treatment. The air circulation test was also used to verify the Computational Fluid Dynamics (CFD) model of the Dragon capsule. The CFD model included the same Dragon internal geometry that was assembled for the test. This paper will describe the Dragon air circulation system design which has been verified by testing the system and with CFD analysis.

  9. Neuroimaging of cerebral vasculitis

    International Nuclear Information System (INIS)

    Wengenroth, M.; Saam, T.; Haehnel, S.

    2016-01-01

    Cerebral vasculitis can have a variety of origins. Furthermore, there are no vasculitis-specific symptoms or imaging signs and vasculitis of the CNS can mimic many other neurological diseases, which require different treatment approaches. Thus, the clinical and radiological diagnosis of cerebral vasculitis is challenging. Magnetic resonance imaging (MRI) and MR angiography (MRA) should be the radiological imaging methods of choice to assess the degree of parenchymal damage and to detect vessel wall changes. If the results are unclear digital subtraction angiography (DSA) should be pursued in order to also detect changes in medium sized vessels. Vasculitis of small vessels cannot be detected by vascular imaging and requires brain or leptomeningeal biopsy. In this review we present the current diagnostic approach and a variety of imaging findings in cerebral vasculitis and discuss the main radiological differential diagnoses. (orig.) [de

  10. Duplicated middle cerebral artery

    Science.gov (United States)

    Perez, Jesus; Machado, Calixto; Scherle, Claudio; Hierro, Daniel

    2009-01-01

    Duplicated middle cerebral artery (DMCA) is an anomalous vessel arising from the internal carotid artery. The incidence DMCA is relatively law, and an association between this anomaly and cerebral aneurysms has been documented. There is a controversy whether DMCA may have perforating arteries. This is an important fact to consider in aneurysm surgery. We report the case of a 34-year-old black woman who suffered a subarachnoid hemorrhage and the angiography a left DMCA, and an aneurysm in an inferior branch of the main MCA. The DMCA and the MCA had perforating arteries. The aneurysm was clipped without complications. The observation of perforating arteries in our patient confirms that the DMCA may have perforating arteries. This is very important to be considered in cerebral aneurysms surgery. Moreover, the DMCA may potentially serve as a collateral blood supply to the MCA territory in cases of MCA occlusion. PMID:22140405

  11. Diaschisis with cerebral infarction

    Energy Technology Data Exchange (ETDEWEB)

    Slater, R.; Reivich, M.; Goldberg, H.; Banka, R.; Greenberg, J.

    1977-01-01

    Fifteen patients admitted to Philadelphia General Hospital with acute strokes had repeated measurements of cerebral blood flow measured by the /sup 133/X inhalation method. A progressive decline in cerebral blood flow in both hemispheres was observed during the first week after infarction in twelve of these patients. This decline could be partially explained by loss of autoregulation, but could not be correlated with level of consciousness, clinical status of PCO2. This progressive decline in flow in the non-ischemic hemisphere indicates a process more complex than a simple destruction of axonal afferants to neurons as implied by the term diaschisis. The flow changes in the non-ischemic hemisphere are likely caused by a combination of the immediate effects of decreased neuronal stimulation modified by loss of autoregulation, release of vasoactive substances, cerebral edema, and other factors.

  12. Cerebral hemodynamics in migraine

    DEFF Research Database (Denmark)

    Hachinski, V C; Olesen, Jes; Norris, J W

    1977-01-01

    Clinical and angiographic findings in migraine are briefly reviewed in relation to cerebral hemodynamic changes shown by regional cerebral blood flow (rCBF) studies. Three cases of migraine studied by the intracarotid xenon 133 method during attacks are reported. In classic migraine, with typical...... prodromal symptoms, a decrease in cerebral blood flow has been demonstrated during the aura. Occasionally, this flow decrease persists during the headache phase. In common migraine, where such prodromata are not seen, a flow decrease has not been demonstrated. During the headache phase of both types...... of migraine, rCBF has usually been found to be normal or in the high range of normal values. The high values may represent postischemic hyperemia, but are probably more frequently secondary to arousal caused by pain. Thus, during the headache phase rCBF may be subnormal, normal or high. These findings do...

  13. Effect of Blood Collection Tube Type and Time to Processing on the Enumeration and High-Content Characterization of Circulating Tumor Cells Using the High-Definition Single-Cell Assay.

    Science.gov (United States)

    Rodríguez-Lee, Mariam; Kolatkar, Anand; McCormick, Madelyn; Dago, Angel D; Kendall, Jude; Carlsson, Nils Anders; Bethel, Kelly; Greenspan, Emily J; Hwang, Shelley E; Waitman, Kathryn R; Nieva, Jorge J; Hicks, James; Kuhn, Peter

    2018-02-01

    - As circulating tumor cell (CTC) assays gain clinical relevance, it is essential to address preanalytic variability and to develop standard operating procedures for sample handling in order to successfully implement genomically informed, precision health care. - To evaluate the effects of blood collection tube (BCT) type and time-to-assay (TTA) on the enumeration and high-content characterization of CTCs by using the high-definition single-cell assay (HD-SCA). - Blood samples of patients with early- and advanced-stage breast cancer were collected into cell-free DNA (CfDNA), EDTA, acid-citrate-dextrose solution, and heparin BCTs. Time-to-assay was evaluated at 24 and 72 hours, representing the fastest possible and more routine domestic shipping intervals, respectively. - We detected the highest CTC levels and the lowest levels of negative events in CfDNA BCT at 24 hours. At 72 hours in this BCT, all CTC subpopulations were decreased with the larger effect observed in high-definition CTCs and cytokeratin-positive cells smaller than white blood cells. Overall cell retention was also optimal in CfDNA BCT at 24 hours. Whole-genome copy number variation profiles were generated from single cells isolated from all BCT types and TTAs. Cells from CfDNA BCT at 24-hour TTA exhibited the least noise. - Circulating tumor cells can be identified and characterized under a variety of collection, handling, and processing conditions, but the highest quality can be achieved with optimized conditions. We quantified performance differences of the HD-SCA for specific preanalytic variables that may be used as a guide to develop best practices for implementation into patient care and/or research biorepository processes.

  14. Cerebral fat embolism

    International Nuclear Information System (INIS)

    Sakamoto, Toshihisa; Sawada, Yusuke; Yukioka, Tetsuo; Nishide, Kazuyuki; Yoshioka, Toshiharu

    1982-01-01

    A case of cerebral fat embolism is reported. A 18-year-old patient with multiple bone fractures was in semiconma immediately after an injury. Brain CT showed no brain swelling or intracranial hematoma. Hypoxemia and alcoholemia were noted on admission, which returned to normal without improvement of consciousness level. In addition, respiratory symptoms with positive radiographic changes, tachycardia, pyrexia, sudden drop in hemoglobin level, and sudden thrombocytopenia developed. These symptoms were compatible with Gurd's criteria of systemic fat embolism. Eight days after injury, multiple low density areas appeared on CT and disappeared within the subsequent two weeks, and subdural effusion with cerebral atrophy developed. These CT findings were not considered due to cerebral trauma. Diagnosis of cerebral fat embolism was made. The subdural effusion was drained. Neurologic and pulmonary recoveries took place slowly and one month following the injury the patient became alert and exhibited fully coordinated limb movement. The CT scans of the present case well corresponded with hitherto reported pathological findings. Petechiae in the white matter must have developed on the day of injury, which could not be detected by CT examination. It is suggested that some petechial regions fused to purpuras and then gradually resolved when they were detected as multiple low density areas on CT. CT in the purpuras phase would have shown these lesions as high density areas. These lesions must have healed with formation of tiny scars and blood pigment which were demonstrated as the disappearance of multiple low density areas by CT examination. Cerebral atrophy and subsequent subdural effusion developed as a result of demyelination. The patient took the typical clinical course of cerebral fat embolism and serial CT scans served for its assessment. (author)

  15. Gammagraphy of cerebral perfusion

    International Nuclear Information System (INIS)

    Vazquez, Silvia

    2003-01-01

    Important aspects of the gammagraphy of cerebral perfusion and the diverse clinical applications in the neurological diseases are comment in this article. We focus in the usefulness of the photon emission cerebral tomography (SPECT) and its capacity to cross the hemato encephalic barrier through the use of radiopharmacons like 99 mTc-H M-PAO and 99mTc-EDC, thus managing to offer functional data on the captantes neurons of the radiopharmacon. The clinical applications of SPECT are studied; cerebrovascular disease, transient ischemic attacks, dementias, Alzheimer disease, as well as other neurological diseases are referred. (The author)

  16. Cerebral blood flow variations in CNS lupus

    International Nuclear Information System (INIS)

    Kushner, M.J.; Tobin, M.; Fazekas, F.; Chawluk, J.; Jamieson, D.; Freundlich, B.; Grenell, S.; Freemen, L.; Reivich, M.

    1990-01-01

    We studied the patterns of cerebral blood flow (CBF), over time, in patients with systemic lupus erythematosus and varying neurologic manifestations including headache, stroke, psychosis, and encephalopathy. For 20 paired xenon-133 CBF measurements, CBF was normal during CNS remissions, regardless of the symptoms. CBF was significantly depressed during CNS exacerbations. The magnitude of change in CBF varied with the neurologic syndrome. CBF was least affected in patients with nonspecific symptoms such as headache or malaise, whereas patients with encephalopathy or psychosis exhibited the greatest reductions in CBF. In 1 patient with affective psychosis, without clinical or CT evidence of cerebral ischemia, serial SPECT studies showed resolution of multifocal cerebral perfusion defects which paralleled clinical recovery

  17. New Wavelet Neurovascular Bundle for Bedside Evaluation of Cerebral Autoregulation and Neurovascular Coupling in Newborns with Hypoxic-Ischemic Encephalopathy.

    Science.gov (United States)

    Chalak, Lina F; Zhang, Rong

    2017-01-01

    Neonatal encephalopathy (NE) resulting from birth asphyxia constitutes a major global public health burden for millions of infants every year, and despite therapeutic hypothermia, half of these neonates have poor neurological outcomes. As new neuroprotective interventions are being studied in clinical trials, there is a critical need to establish physiological surrogate markers of therapeutic efficacy, to guide patient selection and/or to modify the therapeutic intervention. The challenge in the field of neonatal brain injury has been the difficulty of clinically discerning NE severity within the short therapeutic window after birth or of analyzing the dynamic aspects of the cerebral circulation in sick NE newborns. To address this roadblock, we have recently developed a new "wavelet neurovascular bundle" analytical system that can measure cerebral autoregulation (CA) and neurovascular coupling (NVC) at multiple time scales under dynamic, nonstationary clinical conditions. This wavelet analysis may allow noninvasive quantification at the bedside of (1) CA (combining metrics of blood pressure and cerebral near-infrared spectroscopy, NIRS) and (2) NVC (combining metrics obtained from NIRS and EEG) in newborns with encephalopathy without mathematical assumptions of linear and stationary systems. In this concept paper, we present case examples of NE using the proposed physiological wavelet metrics of CA and NVC. The new approach, once validated in large NE studies, has the potential to optimize the selection of candidates for therapeutic decision-making, and the prediction of neurocognitive outcomes. © 2017 S. Karger AG, Basel.

  18. High Throughput qPCR Expression Profiling of Circulating MicroRNAs Reveals Minimal Sex- and Sample Timing-Related Variation in Plasma of Healthy Volunteers.

    Directory of Open Access Journals (Sweden)

    Catherine Mooney

    Full Text Available MicroRNAs are a class of small non-coding RNA that regulate gene expression at a post-transcriptional level. MicroRNAs have been identified in various body fluids under normal conditions and their stability as well as their dysregulation in disease opens up a new field for biomarker study. However, diurnal and day-to-day variation in plasma microRNA levels, and differential regulation between males and females, may affect biomarker stability. A QuantStudio 12K Flex Real-Time PCR System was used to profile plasma microRNA levels using OpenArray in male and female healthy volunteers, in the morning and afternoon, and at four time points over a one month period. Using this system we were able to run four OpenArray plates in a single run, the equivalent of 32 traditional 384-well qPCR plates or 12,000 data points. Up to 754 microRNAs can be identified in a single plasma sample in under two hours. 108 individual microRNAs were identified in at least 80% of all our samples which compares favourably with other reports of microRNA profiles in serum or plasma in healthy adults. Many of these microRNAs, including miR-16-5p, miR-17-5p, miR-19a-3p, miR-24-3p, miR-30c-5p, miR-191-5p, miR-223-3p and miR-451a are highly expressed and consistent with previous studies using other platforms. Overall, microRNA levels were very consistent between individuals, males and females, and time points and we did not detect significant differences in levels of microRNAs. These results suggest the suitability of this platform for microRNA profiling and biomarker discovery and suggest minimal confounding influence of sex or sample timing. However, the platform has not been subjected to rigorous validation which must be demonstrated in future biomarker studies where large differences may exist between disease and control samples.

  19. Cerebral atrophic and degenerative changes following various cerebral diseases, (1)

    International Nuclear Information System (INIS)

    Kino, Masao; Anno, Izumi; Yano, Yuhiko; Anno, Yasuro.

    1980-01-01

    Patients having cerebral atrophic and degenerative changes following hypoglycemia, cerebral contusion, or cerebral hypoxia including cerebrovascular disorders were reported. Description was made as to cerebral changes visualized on CT images and clinical courses of a patient who revived 10 minutes after heart stoppage during neurosurgery, a newborn with asphyxia, a patient with hypoglycemia, a patient who suffered from asphyxia by an accident 10 years before, a patient with carbon monoxide poisoning at an acute stage, a patient who had carbon monoxide poisoning 10 years before, a patient with diffuse cerebral ischemic changes, a patient with cerebral edema around metastatic tumor, a patient with respiration brain, a patient with neurological sequelae after cerebral contusion, a patient who had an operation to excise right parietal lobe artery malformation, and a patient who was shooted by a machine gun and had a lead in the brain for 34 years. (Tsunoda, M.)

  20. Arctic circulation regimes.

    Science.gov (United States)

    Proshutinsky, Andrey; Dukhovskoy, Dmitry; Timmermans, Mary-Louise; Krishfield, Richard; Bamber, Jonathan L

    2015-10-13

    Between 1948 and 1996, mean annual environmental parameters in the Arctic experienced a well-pronounced decadal variability with two basic circulation patterns: cyclonic and anticyclonic alternating at 5 to 7 year intervals. During cyclonic regimes, low sea-level atmospheric pressure (SLP) dominated over the Arctic Ocean driving sea ice and the upper ocean counterclockwise; the Arctic atmosphere was relatively warm and humid, and freshwater flux from the Arctic Ocean towards the subarctic seas was intensified. By contrast, during anticylonic circulation regimes, high SLP dominated driving sea ice and the upper ocean clockwise. Meanwhile, the atmosphere was cold and dry and the freshwater flux from the Arctic to the subarctic seas was reduced. Since 1997, however, the Arctic system has been under the influence of an anticyclonic circulation regime (17 years) with a set of environmental parameters that are atypical for this regime. We discuss a hypothesis explaining the causes and mechanisms regulating the intensity and duration of Arctic circulation regimes, and speculate how changes in freshwater fluxes from the Arctic Ocean and Greenland impact environmental conditions and interrupt their decadal variability. © 2015 The Authors.

  1. Isolated transient vertigo: posterior circulation ischemia or benign origin?

    Science.gov (United States)

    Blasberg, Tobias F; Wolf, Lea; Henke, Christian; Lorenz, Matthias W

    2017-06-14

    Isolated transient vertigo can be the only symptom of posterior circulation ischemia. Thus, it is important to differentiate isolated vertigo of a cerebrovascular origin from that of more benign origins, as patients with cerebral ischemia have a much higher risk for future stroke than do those with 'peripheral' vertigo. The current study aims to identify risk factors for cerebrovascular origin of isolated transient vertigo, and for future cerebrovascular events. From the files of 339 outpatients with isolated transient vertigo we extracted history, clinical and technical findings, diagnosis, and follow-up information on subsequent stroke or transient ischemic attack (TIA). Risk factors were analyzed using multivariate regression models (logistic or Cox) and reconfirmed in univariate analyses. On first presentation, 48 (14.2%) patients received the diagnosis 'probable or definite cerebrovascular vertigo'. During follow-up, 41 patients suffered stroke or TIA (event rate 7.9 per 100 person years, 95% confidence interval (CI) 5.5-10.4), 26 in the posterior circulation (event rate 4.8 per 100 person years, 95% CI 3.0-6.7). The diagnosis was not associated with follow-up cerebrovascular events. In multivariate models testing multiple potential determinants, only the presentation mode was consistently associated with the diagnosis and stroke risk: patients who presented because of vertigo (rather than reporting vertigo when they presented for other reasons) had a significantly higher risk for future stroke or TIA (p = 0.028, event rate 13.4 vs. 5.4 per 100 person years) and for future posterior circulation stroke or TIA (p = 0.044, event rate 7.8 vs. 3.5 per 100 person years). We here report for the first time follow-up stroke rates in patients with transient isolated vertigo. In such patients, the identification of those with cerebrovascular origin remains difficult, and presentation mode was found to be the only consistent risk factor. Confirmation in an independent

  2. Diarrhea caused by circulating agents.

    Science.gov (United States)

    Fabian, Elisabeth; Kump, Patrizia; Krejs, Guenter J

    2012-09-01

    Circulating agents cause intestinal secretion or changes in motility with decreased intestinal transit time, resulting in secretory-type diarrhea. Secretory diarrhea as opposed to osmotic diarrhea is characterized by large-volume, watery stools, often more than 1 L per day; by persistence of diarrhea when patients fast; and by the fact that on analysis of stool-water, measured osmolarity is identical to that calculated from the electrolytes present. Although sodium plays the main role in water and electrolyte absorption, chloride is the major ion involved in secretion. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. Cerebral malaria: susceptibility weighted MRI

    Directory of Open Access Journals (Sweden)

    Vinit Baliyan

    2015-03-01

    Full Text Available Cerebral malaria is one of the fatal complications of Plasmodium falciparum infection. Pathogenesis involves cerebral microangiopathy related to microvascular plugging by infected red blood cells. Conventional imaging with MRI and CT do not reveal anything specific in case of cerebral malaria. Susceptibility weighted imaging, a recent advance in the MRI, is very sensitive to microbleeds related to microangiopathy. Histopathological studies in cerebral malaria have revealed microbleeds in brain parenchyma secondary to microangiopathy. Susceptibility weighted imaging, being exquisitely sensitive to microbleeds may provide additional information and improve the diagnostic accuracy of MRI in cerebral malaria.

  4. The Scrap Collection per Industry Sector and the Circulation Times of Steel in the U.S. between 1900 and 2016, Calculated Based on the Volume Correlation Model

    Directory of Open Access Journals (Sweden)

    Alicia Gauffin

    2018-05-01

    Full Text Available On the basis of the Volume Correlation Model (VCM as well as data on steel consumption and scrap collection per industry sector (construction, automotive, industrial goods, and consumer goods, it was possible to estimate service lifetimes of steel in the United States between 1900 and 2016. Input data on scrap collection per industry sector was based on a scrap survey conducted by the World Steel Association for a static year in 2014 in the United States. The lifetimes of steel calculated with the VCM method were within the range of previously reported measured lifetimes of products and applications for all industry sectors. Scrapped (and apparent lifetimes of steel compared with measured lifetimes were calculated to be as follows: a scrapped lifetime of 29 years for the construction sector (apparent lifetime: 52 years compared with 44 years measured in 2014. Industrial goods: 16 (27 years compared with 19 years measured in 2010. Consumer goods: 12 (14 years compared with 13 years measured in 2014. Automotive sector: 14 (19 years compared with 17 years measured in 2011. Results show that the VCM can estimate reasonable values of scrap collection and availability per industry sector over time.

  5. High Altitude Cerebral Edema

    Science.gov (United States)

    1986-03-01

    described neuropathological findings of cerebral edema and wi4espread petechial hemorrhages in two HAPE fatalities and later reported (52...lethargy, thirst, indigestion, hysterical outburst o: other behavior disturbances, decreased concentration, fever , couhh and peripheral edema (52...autopsy results from the two fatalities in their series. In both cases multiple, widespread petechial hemorrhages were noted throughout the brain. One

  6. [Retrospective analysis of risk factors in 900 patients with ischemic cerebral stroke of wind-phlegm collateral obstruction syndrome and qi deficiency blood stasis syndrome in Wuhan District].

    Science.gov (United States)

    Qiu, Xin; Wang, Kai-xin; Chen, Guo-hua

    2011-11-01

    To analyze the correlation between risk factors and ischemic cerebral stroke of wind-phlegm collateral obstruction syndrome and qi deficiency blood stasis syndrome. Totally 900 patients of the two syndrome types were recruited. Risk factors correlated to ischemic cerebral stroke such as gender, age, time of onset, site of infarction, tongue proper, tongue fur, pulse picture, hypertension, diabetes, past stroke history, hyperlipidemia, hematocrit, smoking, drinking, genetic factor, blood type, complications were analyzed using Chi-square test and non-conditional Logistic regression analysis. Statistical significance existed between the two syndrome types in age (X2 = 8.2392, P = 0.0413), hyperlipidemia (X2 = 4.8386, P = 0.0278), tongue proper (X2 = 7.9470, P = 0.0048), and tongue fur (X2 = 4.3298, P = 0.0375). Statistical significance existed between the two syndrome types in hyperlipidemia, tongue proper, and tongue fur, and their OR value was 0.699 (P = 0.0282), 0.332 (P =0.0071), and 0.667 (P = 0.0382) respectively. The OR value of the past stroke history was 3.226 (P = 0.0314), that of complications 0.203 (P = 0.0705), and that of anterior circulation infarction 0.214 (P = 0.0098). Among different ages groups, the constituent ratio of qi deficiency blood stasis syndrome was obviously higher than that of wind-phlegm collateral obstruction syndrome. Besides, patients of qi deficiency blood stasis syndrome were liable to suffer from hyperlipidemia, anterior circulation infarction, and complications. The age, blood lipid levels, site of infarction, complications are closely correlated with Chinese syndrome types of ischemic cerebral stroke, which can provide objective indices for typing ischemic cerebral stroke.

  7. Multi-modal assessment of neurovascular coupling during cerebral ischaemia and reperfusion using remote middle cerebral artery occlusion

    DEFF Research Database (Denmark)

    Sutherland, Brad A; Fordsmann, Jonas C; Martin, Chris

    2017-01-01

    . Male Wistar rats were subjected to remote middle cerebral artery occlusion, where a long filament was advanced intraluminally through a guide cannula in the common carotid artery. Transcallosal stimulation evoked increases in blood flow, tissue oxygenation and neuronal activity, which were diminished...... that neurovascular dysfunction was not sustained. These data show for the first time that the rat remote middle cerebral artery occlusion model coupled with transcallosal stimulation provides a novel method for continuous assessment of hyperacute neurovascular coupling changes during ischaemia and reperfusion......Hyperacute changes in cerebral blood flow during cerebral ischaemia and reperfusion are important determinants of injury. Cerebral blood flow is regulated by neurovascular coupling, and disruption of neurovascular coupling contributes to brain plasticity and repair problems. However, it is unknown...

  8. Hyperventilation, cerebral perfusion, and syncope

    DEFF Research Database (Denmark)

    Immink, R V; Pott, F C; Secher, N H

    2014-01-01

    dioxide (PaCO2) and oxygen (PaO2) partial pressures so that hypercapnia/hypoxia increases and hypocapnia/hyperoxia reduces global cerebral blood flow. Cerebral hypoperfusion and TLOC have been associated with hypocapnia related to HV. Notwithstanding pronounced cerebrovascular effects of PaCO2...... the contribution of a low PaCO2 to the early postural reduction in middle cerebral artery blood velocity is transient. HV together with postural stress does not reduce cerebral perfusion to such an extent that TLOC develops. However when HV is combined with cardiovascular stressors like cold immersion or reduced...... cardiac output brain perfusion becomes jeopardized. Whether, in patients with cardiovascular disease and/or defect, cerebral blood flow cerebral control HV-induced hypocapnia elicits cerebral hypoperfusion, leading to TLOC, remains to be established....

  9. Psychiatric and subjective symptoms and cerebral blood flow in patients with chronic cerebral infarction after treatment with Ca antagonist (nilvadipine). Quantitative measurement of cerebral blood flow by the 123IMP-SPECT ARG method

    International Nuclear Information System (INIS)

    Sakayori, Osamu; Kitamura, Shin; Mishina, Masahiro; Yamazaki, Mineo; Terashi, Akirou

    1997-01-01

    Psychiatric and subjective symptoms such as headache, dizziness, lack of spontaneity, anxiety, and a depressive state are often found in patients with chronic cerebral infarction. Some Ca antagonists are reported to relieve such symptoms. The purpose of the present study was to investigate the relationship between psychiatric and subjective symptoms and cerebral blood flow (CBF) in cerebral infarction and to evaluate the clinical effects of Ca antagonists from the standpoint of the cerebral circulation. Nilvadipine was administered to is patients with chronic cerebral infarction and their CBF was measured by the 123 IMP-SPECT ARG method before and at 8 weeks after the nilvadipine treatment. The CBF in patients with hypertension was increased by 11% after giving nilvadipine. Patients without hypertension showed no tendency for elevation of their CBF. Patients who were relieved from some psychiatric symptoms revealed a 14% increase of CBF in all cortical regions, and a significant increase was noted in the frontal and temporal regions. In other patients without changes in psychiatric symptoms, the CBF did not increase in any of the cortical regions. No relationship between symptoms and CBF was observed in any of the patients with subjective symptoms. Our study demonstrated a close correlation between psychiatric symptoms and CBF. We speculate that psychiatric symptoms in chronic cerebral infarction may reflect diffuse brain dysfunctions. We also conclude that nilvadipine is more effective in relieving psychiatric symptoms in patients with hypertensive cerebral infarction. It is inferred that nilvadipine may be more effective in relieving psychiatric symptoms in patients with hypertension. (author)

  10. A simple method for regional cerebral blood flow measurement by one-point arterial blood sampling and 123I-IMP microsphere model (part 2). A study of time correction of one-point blood sample count

    International Nuclear Information System (INIS)

    Masuda, Yasuhiko; Makino, Kenichi; Gotoh, Satoshi

    1999-01-01

    In our previous paper regarding determination of the regional cerebral blood flow (rCBF) using the 123 I-IMP microsphere model, we reported that the accuracy of determination of the integrated value of the input function from one-point arterial blood sampling can be increased by performing correction using the 5 min: 29 min ratio for the whole-brain count. However, failure to carry out the arterial blood collection at exactly 5 minutes after 123 I-IMP injection causes errors with this method, and there is thus a time limitation. We have now revised out method so that the one-point arterial blood sampling can be performed at any time during the interval between 5 minutes and 20 minutes after 123 I-IMP injection, with addition of a correction step for the sampling time. This revised method permits more accurate estimation of the integral of the input functions. This method was then applied to 174 experimental subjects: one-point blood samples collected at random times between 5 and 20 minutes, and the estimated values for the continuous arterial octanol extraction count (COC) were determined. The mean error rate between the COC and the actual measured continuous arterial octanol extraction count (OC) was 3.6%, and the standard deviation was 12.7%. Accordingly, in 70% of the cases, the rCBF was able to be estimated within an error rate of 13%, while estimation was possible in 95% of the cases within an error rate of 25%. This improved method is a simple technique for determination of the rCBF by 123 I-IMP microsphere model and one-point arterial blood sampling which no longer shows a time limitation and does not require any octanol extraction step. (author)

  11. Cerebral microbleeds in a neonatal rat model.

    Directory of Open Access Journals (Sweden)

    Brianna Carusillo Theriault

    Full Text Available In adult humans, cerebral microbleeds play important roles in neurodegenerative diseases but in neonates, the consequences of cerebral microbleeds are unknown. In rats, a single pro-angiogenic stimulus in utero predisposes to cerebral microbleeds after birth at term, a time when late oligodendrocyte progenitors (pre-oligodendrocytes dominate in the rat brain. We hypothesized that two independent pro-angiogenic stimuli in utero would be associated with a high likelihood of perinatal microbleeds that would be severely damaging to white matter.Pregnant Wistar rats were subjected to intrauterine ischemia (IUI and low-dose maternal lipopolysaccharide (mLPS at embryonic day (E 19. Pups were born vaginally or abdominally at E21-22. Brains were evaluated for angiogenic markers, microhemorrhages, myelination and axonal development. Neurological function was assessed out to 6 weeks.mRNA (Vegf, Cd31, Mmp2, Mmp9, Timp1, Timp2 and protein (CD31, MMP2, MMP9 for angiogenic markers, in situ proteolytic activity, and collagen IV immunoreactivity were altered, consistent with an angiogenic response. Vaginally delivered pups exposed to prenatal IUI+mLPS had spontaneous cerebral microbleeds, abnormal neurological function, and dysmorphic, hypomyelinated white matter and axonopathy. Pups exposed to the same pro-angiogenic stimuli in utero but delivered abdominally had minimal cerebral microbleeds, preserved myelination and axonal development, and neurological function similar to naïve controls.In rats, pro-angiogenic stimuli in utero can predispose to vascular fragility and lead to cerebral microbleeds. The study of microbleeds in the neonatal rat brain at full gestation may give insights into the consequences of microbleeds in human preterm infants during critical periods of white matter development.

  12. External carotid compression: a novel technique to improve cerebral perfusion during selective antegrade cerebral perfusion for aortic arch surgery.

    Science.gov (United States)

    Grocott, Hilary P; Ambrose, Emma; Moon, Mike

    2016-10-01

    Selective antegrade cerebral perfusion (SACP) involving cannulation of either the axillary or innominate artery is a commonly used technique for maintaining cerebral blood flow (CBF) during the use of hypothermic cardiac arrest (HCA) for operations on the aortic arch. Nevertheless, asymmetrical CBF with hypoperfusion of the left cerebral hemisphere is a common occurrence during SACP. The purpose of this report is to describe an adjunctive maneuver to improve left hemispheric CBF during SACP by applying extrinsic compression to the left carotid artery. A 77-yr-old male patient with a history of aortic valve replacement presented for emergent surgical repair of an acute type A aortic dissection of a previously known ascending aortic aneurysm. His intraoperative course included cannulation of the right axillary artery, which was used as the aortic inflow during cardiopulmonary bypass and also allowed for subsequent SACP during HCA. After the onset of HCA, the innominate artery was clamped at its origin to allow for SACP. Shortly thereafter, however, the left-sided cerebral oxygen saturation (SrO2) began to decrease. Augmenting the PaO2, PaCO2 and both SACP pressure and flow failed to increase left hemispheric SrO2. Following the use of ultrasound guidance to confirm the absence of atherosclerotic disease in the carotid artery, external pressure was applied partially compressing the artery. With the carotid compression, the left cerebral saturation abruptly increased, suggesting pressurization of the left cerebral hemispheric circulation and augmentation of CBF. Direct ultrasound visualization and cautious partial compression of the left carotid artery may address asymmetrical CBF that occurs with SACP during HCA for aortic arch surgery. This strategy may lead to improved symmetry of CBF and corresponding cerebral oximetry measurements during aortic arch surgery.

  13. Neuroimaging patterns of cerebral hyperperfusion

    Science.gov (United States)

    Semenov, S.; Portnov, Yu; Semenov, A.; Korotkevich, A.; Kokov, A.

    2017-08-01

    Cerebral hyperperfusion syndrome (CHS) after revascularization is a rare phenomenon associated with post-ischemic (reactive) hyperemia and acute pathological hyperperfusion. First described on perfusion CT as a very often moderate CBF increase, MTT/TTP decrease within 30% like a temporary effect, according to a short-time deterioration of neurological symptoms (vestibular ataxia - 58%, vegetative dysfunction - 100%, asthenic syndrome - 100%) in early postoperative period in patients with cardiac ischemia who had undergone coronary artery bypass surgery. The acute pathological hyperperfusion carotid revascularization is a casuistic phenomenon with two- or three-fold CBV and MTT/TTP increase and high hemorrhage risk. Besides, we detected similar exchanges via perfusion CT called benign hyperemia, which marks extension of MTT/TTP and an increase of CBV from 27% to 48% (average 30%), but with normal CBF-parameters, indicating that venous stasis in acute venous ischemic stroke due cerebral venous sinus-trombosis (68%), only 6% in cardioembolic stroke and appears never in arterial stroke. Territorial coincidence registered for perifocal of necrosis zones of benign hyperemia and vasogenic edema accompanied on MRI (DWI, ADC). Secondary hemorrhagic transformation registered for primary non-hemorrhagic venous stroke in 27%, only in 9% for arterial stroke and in 60% for cardioembolic stroke. Probably, congestion is an increasingly predisposing factor secondary hemorrhaging than necrosis.

  14. Metabolic and circulatory evaluation of acute cerebral ischaemic accidents in man by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Depresseux, J C; Franck, G., Van Cauwenberge, H.

    1987-06-18

    Positron emission tomography and oxygen-15 were used to evaluate the effects of an almitrine-raubasine combination on cerebral blood flow and oxydative metabolism in patients with acute cerebral ischaemia. In 5 patients, aged between 58 and 74 years, with cerebral ischaemic accident in the territory of the middle cerebral artery, blood flow rate, oxygen consumption and brain oxygen extraction were measured before and after a 90-min intravenous infusion of almitrine bismesilate 15 mg and raubasine 5 mg. Only one patient presented with initial relative luxury perfusion, the intensity of which was reduced by the combined treatment. The other 4 patients had focal reduction of cerebral blood flow and oxygen consumption prior to treatment. Satistical analysis conducted on three cerebral areas (epicentre of the lesion, anterior and posterior juxtalesional areas and homologous heterolateral areas) showed a significant 3.6% increase of oxygen consumption in the epicentre, both hemispheres included, and a significant increase of cerebral blood flow in all three areas (3% on the healthy side, 13% on the diseased side). No significant change in oxygen extraction was demonstrated. The authors conclude that acute almitrine-raubasine treatment has beneficial effects on the brain immediately after a cerebral vascular accident, reflecting respect of the circulation-metabolism couple.

  15. Metabolic and circulatory evaluation of acute cerebral ischaemic accidents in man by positron emission tomography

    International Nuclear Information System (INIS)

    Depresseux, J.C.; Franck, G.; Van Cauwenberge, H.

    1987-01-01

    Positron emission tomography and oxygen-15 were used to evaluate the effects of an almitrine-raubasine combination on cerebral blood flow and oxydative metabolism in patients with acute cerebral ischaemia. In 5 patients, aged between 58 and 74 years, with cerebral ischaemic accident in the territory of the middle cerebral artery, blood flow rate, oxygen consumption and brain oxygen extraction were measured before and after a 90-min intravenous infusion of almitrine bismesilate 15 mg and raubasine 5 mg. Only one patient presented with initial relative luxury perfusion, the intensity of which was reduced by the combined treatment. The other 4 patients had focal reduction of cerebral blood flow and oxygen consumption prior to treatment. Satistical analysis conducted on three cerebral areas (epicentre of the lesion, anterior and posterior juxtalesional areas and homologous heterolateral areas) showed a significant 3.6% increase of oxygen consumption in the epicentre, both hemispheres included, and a significant increase of cerebral blood flow in all three areas (3% on the healthy side, 13% on the diseased side). No significant change in oxygen extraction was demonstrated. The authors conclude that acute almitrine-raubasine treatment has beneficial effects on the brain immediately after a cerebral vascular accident, reflecting respect of the circulation-metabolism couple [fr

  16. Quenching phenomena in natural circulation loop

    International Nuclear Information System (INIS)

    Umekawa, Hisashi; Ozawa, Mamoru; Ishida, Naoki

    1995-01-01

    Quenching phenomena has been investigated experimentally using circulation loop of liquid nitrogen. During the quenching under natural circulation, the heat transfer mode changes from film boiling to nucleate boiling, and at the same time flux changes with time depending on the vapor generation rate and related two-phase flow characteristics. Moreover, density wave oscillations occur under a certain operating condition, which is closely related to the dynamic behavior of the cooling curve. The experimental results indicates that the occurrence of the density wave oscillation induces the deterioration of effective cooling of the heat surface in the film and the transition boiling regions, which results in the decrease in the quenching velocity

  17. Quenching phenomena in natural circulation loop

    Energy Technology Data Exchange (ETDEWEB)

    Umekawa, Hisashi; Ozawa, Mamoru [Kansai Univ., Osaka (Japan); Ishida, Naoki [Daihatsu Motor Company, Osaka (Japan)

    1995-09-01

    Quenching phenomena has been investigated experimentally using circulation loop of liquid nitrogen. During the quenching under natural circulation, the heat transfer mode changes from film boiling to nucleate boiling, and at the same time flux changes with time depending on the vapor generation rate and related two-phase flow characteristics. Moreover, density wave oscillations occur under a certain operating condition, which is closely related to the dynamic behavior of the cooling curve. The experimental results indicates that the occurrence of the density wave oscillation induces the deterioration of effective cooling of the heat surface in the film and the transition boiling regions, which results in the decrease in the quenching velocity.

  18. Regional cerebral blood flow in schizophrenics

    Energy Technology Data Exchange (ETDEWEB)

    Uchino, J.; Ohta, Y.; Nakane, Y.; Mori, H.; Hirota, N.; Yonekura, M.

    1987-01-01

    The present study on schizophrenics dealt with the relationship of regional cerebral blood flow (rCBF) to age, disease duration, and treatment length with chlorpromazine hydrochloride (CPZ). Regional cerebral blood flow in 28 cerebral regions of interest was measured by iv injection of /sup 133/X in 54 schizophrenic patients and 39 healthy volunteers. Neither age nor dosage of CPZ significantly influenced rCBF. All patients, including 11 treated for a short period of time (6 months or less), were characterized by having a decreased rCBF over the whole cerebrum. Thirty-four patients treated for a long period of time (2 years or more) had a varied rCBF distribution in the left hemisphere, with the most predominant feature being the decrease in rCBF in the frontal lobe (i.e., hypofrontality); however, there was no linear correlation between rCBF and disease duration. A decreased rCBE in the right occipital region was seen in patients with paranoid schizophrenia, suggesting that manifestations of symptoms may depend on disturbed regions. These results suggest that cerebral dysfunction in schizophrenic patients may not be restricted to the frontal lobe, but cover the whole cerebrum, and that nonuniform dysfunction in various regions of the cerebrum, including the frontal lobe, may be involved in manifestations of symptoms.

  19. Regional cerebral blood flow in schizophrenics

    International Nuclear Information System (INIS)

    Uchino, Jun; Ohta, Yasuyuki; Nakane, Yoshibumi; Mori, Hiroyuki; Hirota, Noriyoshi; Yonekura, Masahiro.

    1987-01-01

    The present study on schizophrenics dealt with the relationship of regional cerebral blood flow (rCBF) to age, disease duration, and treatment length with chlorpromazine hydrochloride (CPZ). Regional cerebral blood flow in 28 cerebral regions of interest was measured by iv injection of X-133 in 54 schizophrenic patients and 39 healthy volunteers. Neither age nor dosage of CPZ significantly influenced rCBF. All patients, including 11 treated for a short period of time (6 months or less), were characterized by having a decreased rCBF over the whole cerebrum. Thirty-four patients treated for a long period of time (2 years or more) had a varied rCBF distribution in the left hemisphere, with the most predominant feature being the decrease in rCBF in the frontal lobe (i.e., ''hypofrontality''); however, there was no linear correlation between rCBF and disease duration. A decreased rCBE in the right occipital region was seen in patients with paranoid schizophrenia, suggesting that manifestations of symptoms may depend on disturbed regions. These results suggest that cerebral dysfunction in schizophrenic patients may not be restricted to the frontal lobe, but cover the whole cerebrum, and that nonuniform dysfunction in various regions of the cerebrum, including the frontal lobe, may be involved in manifestations of symptoms. (Namekawa, K.)

  20. Controlled humidity gas circulators

    International Nuclear Information System (INIS)

    Gruner, S.M.

    1981-01-01

    A programmable circulator capable of regulating the humidity of a gas stream over a wide range of humidity is described. An optical dew-point hygrometer is used as a feedback element to control the addition or removal of water vapor. Typical regulation of the gas is to a dew-point temperature of +- 0.2 0 C and to an accuracy limited by the dew-point hygrometer

  1. Fluid circulation control device

    International Nuclear Information System (INIS)

    Benard, Henri; Henocque, Jean.

    1982-01-01

    Horizontal fluid circulation control device, of the type having a pivoting flap. This device is intended for being fitted in the pipes of hydraulic installation, particularly in a bleed and venting system of a nuclear power station shifting radioactive or contaminated liquids. The characteristic of this device is the cut-out at the top of the flap to allow the air contained in the pipes to flow freely [fr

  2. Surgical approach to giant aneurysms of the anterior circulation.

    Science.gov (United States)

    Giombini, S; Solero, C L; Ferraresi, S; Melcarne, A; Broggi, G; Pluchino, F

    1988-01-01

    The surgical approach to cerebral giant aneurysms is still a source of great concern. We describe our experience with giant aneurysms of the anterior circulation and discuss the different surgical techniques adopted. During the period January 1972-December 1985, a total of 33 patients were operated upon at the Istituto Neurologico "C. Besta" of Milan for a giant aneurysm of the anterior circulation. Nineteen cases had suffered subarachnoid haemorrhage before admission; in 14 cases the hospitalization was due to evidence of mass effect on the surrounding neurovascular structures. All aneurysms were directly approached: in 24 cases the neck was occluded by a suitable clip, in 4 cases intramural thrombosis was attempted, in 3 cases the aneurysms were definitively trapped and in one case aneurysmorrhaphy was performed after resection of the sac. Operative mortality was 12%. Long-term follow-up shows good results whenever exclusion of the aneurysm from cerebral circulation had been achieved, either after removal of the sac or not; on the contrary, only fair or poor results were evident when other surgical techniques were adopted, either electively or out of necessity. The importance of intraoperative protection and monitoring of brain function is stressed.

  3. Improving the Grading Accuracy of Astrocytic Neoplasms Noninvasively by Combining Timing Information with Cerebral Blood Flow: A Multi-TI Arterial Spin-Labeling MR Imaging Study.

    Science.gov (United States)

    Yang, S; Zhao, B; Wang, G; Xiang, J; Xu, S; Liu, Y; Zhao, P; Pfeuffer, J; Qian, T

    2016-12-01

    Systematic and accurate glioma grading has clinical significance. We present the utility of multi-TI arterial spin-labeling imaging and provide the bolus arrival time maps for grading astrocytomas. Forty-three patients with astrocytomas (21 men; mean age, 51 years) were recruited. The classification abilities of conventional MR imaging features, normalized CBF value derived from multi-TI arterial spin-labeling imaging, normalized bolus arrival time, and normalized CBF derived from single-TI arterial spin-labeling were compared in patients with World Health Organization (WHO) grade II, III, and IV astrocytomas. The normalized CBF value derived from multi-TI arterial spin-labeling imaging was higher in patients with higher grade astrocytoma malignancies compared with patients with lower grade astrocytomas, while the normalized bolus arrival time showed the opposite tendency. The normalized CBF value derived from the multi-TI arterial spin-labeling imaging showed excellent performance with areas under the receiver operating characteristic curve of 0.813 (WHO II versus III), 0.964 (WHO II versus IV), 0.872 (WHO III versus IV), and 0.883 (low-grade-versus-high-grade gliomas). The normalized CBF value derived from single-TI arterial spin-labeling imaging could statistically differentiate the WHO II and IV groups (area under the receiver operating characteristic curve = 0.826). The normalized bolus arrival time effectively identified the WHO grades II and III with an area under the receiver operating characteristic curve of 0.836. Combining the normalized CBF value derived from multi-TI arterial spin-labeling imaging and normalized bolus arrival time improved the diagnostic accuracy from 65.10% to 72.10% compared with the normalized CBF value derived from multi-TI arterial spin-labeling imaging being applied independently. The combination of multi-TI arterial spin-labeling imaging and conventional MR imaging had the best performance, with a diagnostic accuracy of 81

  4. Comparison of cerebral microcirculation of alloxan diabetes and healthy mice using laser speckle contrast imaging

    Science.gov (United States)

    Timoshina, Polina A.; Shi, Rui; Zhang, Yang; Zhu, Dan; Semyachkina-Glushkovskaya, Oxana V.; Tuchin, Valery V.; Luo, Qingming

    2015-03-01

    The study of blood microcirculation is one of the most important problems of the medicine. This paper presents results of experimental study of cerebral blood flow microcirculation in mice with alloxan-induced diabetes using Temporal Laser Speckle Imaging (TLSI). Additionally, a direct effect of glucose water solution (concentration 20% and 45%) on blood flow microcirculation was studied. In the research, 20 white laboratory mice weighing 20-30 g were used. The TLSI method allows one to investigate time dependent scattering from the objects with complex dynamics, since it possesses greater temporal resolution. Results show that in brain of animal diabetic group diameter of sagittal vein is increased and the speed of blood flow reduced relative to the control group. Topical application of 20%- or 45%-glucose solutions also causes increase of diameter of blood vessels and slows down blood circulation. The results obtained show that diabetes development causes changes in the cerebral microcirculatory system and TLSI techniques can be effectively used to quantify these alterations.

  5. Doppler Ultrasonographic Parameters for Predicting Cerebral Vascular Reserve in Patients with Acute Ischemic Stroke

    International Nuclear Information System (INIS)

    Jung, Han Young; Lee, Hui Joong; Kim, Hye Jung; Kim, Yong Sun; Kang, Duk Sik

    2006-01-01

    We investigated Doppler ultrasonographic (US) parameters of patients with acute stroke to predict the cerebral vascular reserve (CVR) measured by SPECT. We reviewed the flow velocity and cross-sectional area of the circular vessel at the common, external, and internal carotid arteries (ICA) and the vertebral arteries (VA) in 109 acute stroke patients who underwent SPECT. Flow volume (FV) of each artery was calculated as the product of the angle-corrected time averaged flow velocity and cross-sectional area of the circular vessel. Total cerebral FV (TCBFV) was determined as the sum of the FVs of the right and left ICA and VA. We compared the Doppler US parameters between 44 cases of preserved and 65 cases of impaired CVR. In the preserved CVR group, ICA FV, anterior circulating FV (ACFV) and TCBFV were higher than in the impaired CVR group (p < 0.05, independent t-test). In the impaired CVR group, the ROC curves showed ACFV and TCBFV were suitable parameters to predict CVR (p < 0.05). Doppler US was helpful for understanding the hemodynamic state of acute stroke. FV measurement by Doppler US was useful for predicting CVR

  6. Cerebral localization in antiquity.

    Science.gov (United States)

    Rose, F Clifford

    2009-07-01

    Fragments of neurology can be found in the oldest medical writings in antiquity. Recognizable cerebral localization is seen in Egyptian medical papyri. Most notably, the Edwin Smith papyrus describes hemiplegia after a head injury. Similar echoes can be seen in Homer, the Bible, and the pre-Hippocratic writer Alcmaeon of Croton. While Biblical writers thought that the heart was the seat of the soul, Hippocratic writers located it in the head. Alexandrian anatomists described the nerves, and Galen developed the ventricular theory of cognition whereby mental functions are classified and localized in one of the cerebral ventricles. Medieval scholars, including the early Church Fathers, modified Galenic ventricular theory so as to make it a dynamic model of cognition. Physicians in antiquity subdivided the brain into separate areas and attributed to them different functions, a phenomenon that connects them with modern neurologists.

  7. Cerebral venous thrombosis

    International Nuclear Information System (INIS)

    Soralova, T.; Sevcikova, H.; Petersky, D.

    2014-01-01

    We decided to process this theme due to its nonspecific clinical features as they often cause diagnostic problems not only to clinicians but also to diagnostic. It is important to think of this disease mainly in young women who administer hormonal contraception. Imaging methods play the crucial role in diagnostic of cerebral venous sinus thrombosis. The gold standard is a native CT of brain which shows the venous sinus thrombosis as a hyperdense lesion in the locus of the sinus (dense triangle sign), CT venography shows the sinus thrombosis as a defect in a contrast filling of the venous sinus (empty delta sign). Other investigative methods are magnetic resonance imaging or MRA. In short we also mention quite a rare but more serious thrombosis of profound cerebral veins v. cerebri magna-Galeni, vv. cerebri internae). The importance of early diagnostic and non specificity of symptoms is presented in 3 clinical cases that are the part of this work. (author)

  8. Applications of cerebral SPECT

    Energy Technology Data Exchange (ETDEWEB)

    McArthur, C., E-mail: claire.mcarthur@nhs.net [Department of Neuroradiology, Institute of Neurological Sciences, Glasgow (United Kingdom); Jampana, R.; Patterson, J.; Hadley, D. [Department of Neuroradiology, Institute of Neurological Sciences, Glasgow (United Kingdom)

    2011-07-15

    Single-photon emission computed tomography (SPECT) can provide three-dimensional functional images of the brain following the injection of one of a series of radiopharmaceuticals that crosses the blood-brain barrier and distributes according to cerebral perfusion, neurotransmitter, or cell density. Applications include differentiating between the dementias, evaluating cerebrovascular disease, preoperative localization of epileptogenic foci, diagnosing movement disorders, and evaluation of intracerebral tumours, while also proving a useful research tool. Unlike positronemission tomography (PET), SPECT imaging is widely available and can be performed in any department that has access to a rotating gamma camera. The purpose of this review is to demonstrate the utility of cerebral SPECT and increase awareness of its role in the investigation of neurological and psychiatric disorders.

  9. AβPP/APLP2 Family of Kunitz Serine Proteinase Inhibitors Regulate Cerebral Thrombosis

    Science.gov (United States)

    Xu, Feng; Previti, Mary Lou; Nieman, Marvin T.; Davis, Judianne; Schmaier, Alvin H.; Van Nostrand, William E.

    2009-01-01

    The amyloid β-protein precursor (AβPP) is best recognized as the precursor to the Aβ peptide that accumulates in the brains of patients with Alzheimer’s disease, but less is known about its physiological functions. Isoforms of AβPP that contain a Kunitz-type serine proteinase inhibitor (KPI) domain are expressed in brain and, outside the CNS, in circulating blood platelets. Recently, we showed that KPI-containing forms of AβPP regulates cerebral thrombosis in vivo (Xu et al., 2005 Proc. Natl. Acad. Sci. USA 102:18135–18140; Xu et al. 2007 Stroke 38:2598–2601). Amyloid precursor like protein-2 (APLP2), a closely related homolog to AβPP, also possesses a highly conserved KPI domain. Virtually nothing is known of its function. Here we show that APLP2 also regulates cerebral thrombosis risk. Recombinant purified KPI domains of AβPP and APLP2 both inhibit the plasma clotting in vitro. In a carotid artery thrombosis model both AβPP−/− and APLP2−/− mice exhibit similar significantly shorter times to vessel occlusion compared with wild-type mice indicating a pro-thrombotic phenotype. Similarly, in an experimental model of intracerebral hemorrhage both AβPP−/− and APLP2−/− mice produce significantly smaller hematomas with reduced brain hemoglobin content compared with wild-type mice. Together, these results indicate that AβPP and APLP2 share overlapping anticoagulant functions with regard to regulating thrombosis after cerebral vascular injury. PMID:19403832

  10. The CGRP-antagonist, BIBN4096BS does not affect cerebral or systemic haemodynamics in healthy volunteers

    DEFF Research Database (Denmark)

    Petersen, K A; Birk, S; Lassen, L H

    2005-01-01

    CBF(MCA)) was measured by 133-Xenon inhalation SPECT. The diameter of the temporal and radial artery was measured by high-resolution ultrasound. Systemic haemodynamics and partial pressure of CO(2) (P(et)CO(2)), and adverse events were monitored regularly. BIBN4096BS had no influence on global or regional cerebral blood......BIBN4096BS is a CGRP-antagonist effective in the treatment of migraine. Blocking the receptor of a strong vasodilator involves a theoretical risk of causing cerebral vasoconstriction, a probability not previously investigated with BIBN4096BS. Seven healthy volunteers completed this double...... flow, or on the blood flow velocity in the middle cerebral artery. There was no effect on systemic haemodynamics and adverse events were minor. We conclude that there is no effect of CGRP-receptor blockade on the cerebral or systemic circulation in humans. Circulating CGRP is therefore not likely...

  11. Cerebral ketone body metabolism.

    Science.gov (United States)

    Morris, A A M

    2005-01-01

    Ketone bodies (KBs) are an important source of energy for the brain. During the neonatal period, they are also precursors for the synthesis of lipids (especially cholesterol) and amino acids. The rate of cerebral KB metabolism depends primarily on the concentration in blood; high concentrations occur during fasting and on a high-fat diet. Cerebral KB metabolism is also regulated by the permeability of the blood-brain barrier (BBB), which depends on the abundance of monocarboxylic acid transporters (MCT1). The BBB's permeability to KBs increases with fasting in humans. In rats, permeability increases during the suckling period, but human neonates have not been studied. Monocarboxylic acid transporters are also present in the plasma membranes of neurons and glia but their role in regulating KB metabolism is uncertain. Finally, the rate of cerebral KB metabolism depends on the activities of the relevant enzymes in brain. The activities vary with age in rats, but reliable results are not available for humans. Cerebral KB metabolism in humans differs from that in the rat in several respects. During fasting, for example, KBs supply more of the brain's energy in humans than in the rat. Conversely, KBs are probably used more extensively in the brain of suckling rats than in human neonates. These differences complicate the interpretation of rodent studies. Most patients with inborn errors of ketogenesis develop normally, suggesting that the only essential role for KBs is as an alternative fuel during illness or prolonged fasting. On the other hand, in HMG-CoA lyase deficiency, imaging generally shows asymptomatic white-matter abnormalities. The ability of KBs to act as an alternative fuel explains the effectiveness of the ketogenic diet in GLUT1 deficiency, but its effectiveness in epilepsy remains unexplained.

  12. Radiopharmaceuticals for cerebral studies

    International Nuclear Information System (INIS)

    Leon Cabana, Alba

    1994-01-01

    For obtain good brain scintillation images in nuclear medicine must be used several radiopharmaceuticals. Cerebral studies give a tumors visual image as well as brain anomalities detection and are helpful in the diagnostic diseases . Are described in this work: a cerebrum radiopharmaceuticals classification,labelled compounds proceeding and Tc 99m good properties in for your fast caption, post administration and blood purification for renal way

  13. Three-pattern decomposition of global atmospheric circulation: part II—dynamical equations of horizontal, meridional and zonal circulations

    Science.gov (United States)

    Hu, Shujuan; Cheng, Jianbo; Xu, Ming; Chou, Jifan

    2018-04-01

    The three-pattern decomposition of global atmospheric circulation (TPDGAC) partitions three-dimensional (3D) atmospheric circulation into horizontal, meridional and zonal components to study the 3D structures of global atmospheric circulation. This paper incorporates the three-pattern decomposition model (TPDM) into primitive equations of atmospheric dynamics and establishes a new set of dynamical equations of the horizontal, meridional and zonal circulations in which the operator properties are studied and energy conservation laws are preserved, as in the primitive equations. The physical significance of the newly established equations is demonstrated. Our findings reveal that the new equations are essentially the 3D vorticity equations of atmosphere and that the time evolution rules of the horizontal, meridional and zonal circulations can be described from the perspective of 3D vorticity evolution. The new set of dynamical equations includes decomposed expressions that can be used to explore the source terms of large-scale atmospheric circulation variations. A simplified model is presented to demonstrate the potential applications of the new equations for studying the dynamics of the Rossby, Hadley and Walker circulations. The model shows that the horizontal air temperature anomaly gradient (ATAG) induces changes in meridional and zonal circulations and promotes the baroclinic evolution of the horizontal circulation. The simplified model also indicates that the absolute vorticity of the horizontal circulation is not conserved, and its changes can be described by changes in the vertical vorticities of the meridional and zonal circulations. Moreover, the thermodynamic equation shows that the induced meridional and zonal circulations and advection transport by the horizontal circulation in turn cause a redistribution of the air temperature. The simplified model reveals the fundamental rules between the evolution of the air temperature and the horizontal, meridional

  14. Neonatal cerebral infarction

    International Nuclear Information System (INIS)

    Fujimoto, Shinji; Togari, Hajime; Sobajima, Hisanori; Suzuki, Shigesumi; Wada, Yoshiro; Yokochi, Kenji; Nishimura, Yutaka; Inukai, Kazuhisa; Futamura, Masahide.

    1992-01-01

    In a retrospective multi-center study, we investigated eighteen infants with unilateral cerebral infarctions confirmed by computed tomography (CT) scans. The initial symptoms were observed in all the patients between 0 and 3 days of age. Convulsions or apneic attacks were the initial symptoms in all but one. Only 4 patients had complicated obstetric histories and none showed polycythemia or electrolyte abnormalities. All of the initial CT scans revealed unilaterally localized hypodense areas. In 10, the initial CT scans were performed within 24 hours after the clinical onset. In 16, the lesions were within the territory of the middle cerebral artery, 9 of which also involved the cortico-spinal tract (CST). In the remaining 2 patients, the lesions were located whithin the territory of the posterior cerebral artery. None of the 9 patients without CST involvement developed hemiplegia, whereas 5 (56%) of the 9 with CST involvement had hemiplegia, which is a fairly low incidence compared with that in adult cases. This difference was thought to be related to neonatal brain plasticity. (author)

  15. Tomographic analysis of CBF in cerebral infarction

    International Nuclear Information System (INIS)

    Segawa, Hiromu; Kimura, Kazumoto; Ueda, Yuichi; Nagai, Masakatsu; Yoshimasu, Norio.

    1983-01-01

    Cerebral perfusion was examined in various types of occlusive disease by computed tomographic CBF method. The method utilized has several advantages over conventional studies using isotope, providing high resolution images in a direct relation to CT anatomy. Ten representative cases were presented from 25 consective cases of occlusive disease studied by this method. The method included inhalation of 40 to 60% xenon with serial CT scanning for 25 min. K (build-up rate), lambda (partition coefficient) and CBF values were calculated from ΔHU for each pixel and ΔXe in expired air, based on Fick's principle, and displayed on CRT as K-, lambda- and CBF-map separately. CBF for gray matter of normal control was 82 +- 11 ml/100 gm/min and that for white matter was 24 +- 5 ml/100 gm/min. The ischemic threshold for gray matter appeared to be approximately 20 ml/100 gm/min, as blood flow in focus of complete infarction was below this level. Blood flow between 20 - 30 ml/ 100 gm/min caused some change on CT, such as localized atrophy, cortical thinning, loss of distinction between gray and white matter and decreased or increased density, which were considered to be compatible with pathological changes of laminar necrosis or gliosis with neuronal loss. In a case with occlusion of middle cerebral artery with subsequent recanalization, causing hemorrhagic infarct, hyperemia was observed in the infarcted cortex that was enhanced by iodine. Periventricular lucency observed in two cases, where blood flow was decreased below threshold, could be classified as ''watershed infarction'' mainly involving white matter. In moyamoya disease, blood flow in the anterior circulation was decreased near ischemic level, whereas that in basal ganglia and territory of posterior cerebral artery was fairly preserved, which was compatible with general angiographic finding of this disease. (author)

  16. Analysis of peritumoral cerebral edema of meningiomas

    International Nuclear Information System (INIS)

    Okada, Masaaki; Tanaka, Katsuyuki; Abe, Juzo; Sekino, Hiroaki; Ogawa, Takei; Hayashi, Tatsuo.

    1992-01-01

    Peritumoral edema associated with 28 meningiomas was studied. The results of radiological investigation, using MRI, CT, and angiography, and histological studies were described and correlated with each other in order to clarify the mechanism of peritumoral cerebral edema production. Extensive peritumoral edema was recognized when the venous sinus or cortical veins, especially the superficial and deep Sylvian veins, were invaded and/or compressed markedly by the tumor. Therefore, large tumors (more than 5 cm in diameter) which were located in the parasagittal area and the middle cranial fossa had a tendency to be associated with extensive peritumoral edema. The posterior fossa meningiomas were associated with small edema because there were rich venous channels in the posterior fossa. Although there have been several reports that the peritumoral edema of meningioma would be produced by the vessels of the tumor itself and would migrate through the tumor capsule into the surrounding brain tissue, and although mechanical factors alone are not sufficient to explain peritumoral edema production, we would like to postulate that the longstanding mechanical compression of venous circulation by the meningioma might be an important factor in the production of the peritumoral cerebral edema. (author)

  17. Effects of CDP-choline on neurologic deficits and cerebral glucose metabolism in a rat model of cerebral ischemia

    Energy Technology Data Exchange (ETDEWEB)

    Kakihana, M.; Fukuda, N.; Suno, M.; Nagaoka, A.

    1988-02-01

    The effects of cytidine 5'-diphosphocholine (CDP-choline) on neurologic deficits and cerebral glucose metabolism were studied in a rat model of transient cerebral ischemia. Cerebral ischemia was induced by occluding both common carotid arteries for 20 or 30 minutes 24 hours after the vertebral arteries were permanently occluded by electrocautery. CDP-choline was administered intraperitoneally twice daily for 4 days after reestablishing carotid blood flow. CDP-choline at two dosages (50 and 250 mg/kg) shortened the time required for recovery of spontaneous motor activity in a dose-related manner; recovery time was measured early after reperfusion. Neurologic signs were observed for 10 days. High-dose CDP-choline improved neurologic signs in the rats within 20-30 minutes of ischemia. When cerebral glucose metabolism was assessed on Day 4, increases in the levels of glucose and pyruvate were accompanied by decreases in the synthesis of labeled acetylcholine from uniformly labeled (/sup 14/C)glucose measured in the cerebral cortex of rats with 30 minutes of ischemia. High-dose CDP-choline also attenuated changes in these variables. CDP-(1,2-/sup 14/C)choline injected intravenously 10 minutes after reperfusion was used for membrane lipid biosynthesis. These results indicate that CDP-choline has beneficial effects on brain dysfunction induced by cerebral ischemia, which may be due in part to the restorative effects of CDP-choline on disturbed cerebral glucose metabolism, probably by stimulating phospholipid biosynthesis.

  18. Effects of CDP-choline on neurologic deficits and cerebral glucose metabolism in a rat model of cerebral ischemia

    International Nuclear Information System (INIS)

    Kakihana, M.; Fukuda, N.; Suno, M.; Nagaoka, A.

    1988-01-01

    The effects of cytidine 5'-diphosphocholine (CDP-choline) on neurologic deficits and cerebral glucose metabolism were studied in a rat model of transient cerebral ischemia. Cerebral ischemia was induced by occluding both common carotid arteries for 20 or 30 minutes 24 hours after the vertebral arteries were permanently occluded by electrocautery. CDP-choline was administered intraperitoneally twice daily for 4 days after reestablishing carotid blood flow. CDP-choline at two dosages (50 and 250 mg/kg) shortened the time required for recovery of spontaneous motor activity in a dose-related manner; recovery time was measured early after reperfusion. Neurologic signs were observed for 10 days. High-dose CDP-choline improved neurologic signs in the rats within 20-30 minutes of ischemia. When cerebral glucose metabolism was assessed on Day 4, increases in the levels of glucose and pyruvate were accompanied by decreases in the synthesis of labeled acetylcholine from uniformly labeled [ 14 C]glucose measured in the cerebral cortex of rats with 30 minutes of ischemia. High-dose CDP-choline also attenuated changes in these variables. CDP-[1,2- 14 C]choline injected intravenously 10 minutes after reperfusion was used for membrane lipid biosynthesis. These results indicate that CDP-choline has beneficial effects on brain dysfunction induced by cerebral ischemia, which may be due in part to the restorative effects of CDP-choline on disturbed cerebral glucose metabolism, probably by stimulating phospholipid biosynthesis

  19. Cerebral infarction secondary to temporal lobe herniation in head trauma: a CT study

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Hyoung; Park, Eui Dong; Kim, Hyung Jin; Han, Jong Woo; Chung, Sung Hoon; Ha, Choong Kun; Kim, Jae Il [College of Medicine, Gyeongsang National University, Jinju (Korea, Republic of)

    1992-11-15

    Cerebral infarction is a known complication of temporal lobe herniation caused by a traumatic intracranial lesion. To ascertain the frequency, time of recognition, and influence on mortality of posttraumatic cerebral infarction secondary to temporal lobe herniation, we retrospectively reviewed brain CT scans and clinical records of 55 patients who had CT and clinical signs of temporal lobe herniation on admission date. Cerebral infarctions were recognized in seven (12.7%) patients on CT scans taken within two days after admission (mean: 1.3 days). Cerebral infarctions were in the terrtiories of the posterior cerebral artery in all seven patients, two of whom had infarctions of the anterior choroidal artery as well. Mortality (71.4%) for these seven patients was not statistically significant from that (50%) of patients without cerebral infarction admitted with the same range of Glasgow Coma Scale score. The result suggests that such cerebral infarction dose not greatly influence patient's mortality.

  20. Roadmap for cardiovascular circulation model

    Science.gov (United States)

    Bradley, Christopher P.; Suresh, Vinod; Mithraratne, Kumar; Muller, Alexandre; Ho, Harvey; Ladd, David; Hellevik, Leif R.; Omholt, Stig W.; Chase, J. Geoffrey; Müller, Lucas O.; Watanabe, Sansuke M.; Blanco, Pablo J.; de Bono, Bernard; Hunter, Peter J.

    2016-01-01

    Abstract Computational models of many aspects of the mammalian cardiovascular circulation have been developed. Indeed, along with orthopaedics, this area of physiology is one that has attracted much interest from engineers, presumably because the equations governing blood flow in the vascular system are well understood and can be solved with well‐established numerical techniques. Unfortunately, there have been only a few attempts to create a comprehensive public domain resource for cardiovascular researchers. In this paper we propose a roadmap for developing an open source cardiovascular circulation model. The model should be registered to the musculo‐skeletal system. The computational infrastructure for the cardiovascular model should provide for near real‐time computation of blood flow and pressure in all parts of the body. The model should deal with vascular beds in all tissues, and the computational infrastructure for the model should provide links into CellML models of cell function and tissue function. In this work we review the literature associated with 1D blood flow modelling in the cardiovascular system, discuss model encoding standards, software and a model repository. We then describe the coordinate systems used to define the vascular geometry, derive the equations and discuss the implementation of these coupled equations in the open source computational software OpenCMISS. Finally, some preliminary results are presented and plans outlined for the next steps in the development of the model, the computational software and the graphical user interface for accessing the model. PMID:27506597

  1. Magnetic resonance angiography in suspected cerebral vasculitis

    International Nuclear Information System (INIS)

    Demaerel, Philippe; De Ruyter, Nele; Wilms, Guido; Maes, Frederik; Velghe, Beatrijs

    2004-01-01

    The purpose of this study was to determine the technical capacity and diagnostic accuracy of 3D time-of-flight magnetic resonance angiography (MRA) in suspected cerebral vasculitis in a retrospective analysis of MRA and digital subtraction angiography (DSA) in 14 young patients with clinical and/or radiological suspicion of cerebral vasculitis. A total of nine arteries were evaluated in each patient. Consensus review of DSA by three observers was the reference standard. The sensitivity for detecting a stenosis varied from 62 to 79% for MRA and from 76 to 94% for DSA, depending on the observer. The specificity for detecting a stenosis varied from 83 to 87% for MRA and from 83 to 97% for DSA. Using the criterion ''more than two stenoses in at least two separate vascular distributions'' to consider the examination as being true positive, the false-positive rates for MRA and DSA were comparable. MRA plays a role as the first angiographical examination in the diagnostic work-up of suspected cerebral vasculitis. When more than two stenoses in at least two separate vascular distributions are depicted on MRA, DSA is not expected to add a significant diagnostic contribution in a patient with suspected cerebral vasculitis. DSA remains necessary when MRA is normal or when less than three stenoses are seen. (orig.)

  2. Magnetic resonance angiography in suspected cerebral vasculitis

    Energy Technology Data Exchange (ETDEWEB)

    Demaerel, Philippe; De Ruyter, Nele; Wilms, Guido [Department of Radiology, Universitair Ziekenhuis, KU Leuven, 3000, Leuven (Belgium); Maes, Frederik [Department of Medical Imaging Computing, Universitair Ziekenhuis, KU Leuven, 3000, Leuven (Belgium); Velghe, Beatrijs [Department of Radiology, Ziekenhuis Oost-Limburg, Schiepse Bos 6, 3600, Genk (Belgium)

    2004-06-01

    The purpose of this study was to determine the technical capacity and diagnostic accuracy of 3D time-of-flight magnetic resonance angiography (MRA) in suspected cerebral vasculitis in a retrospective analysis of MRA and digital subtraction angiography (DSA) in 14 young patients with clinical and/or radiological suspicion of cerebral vasculitis. A total of nine arteries were evaluated in each patient. Consensus review of DSA by three observers was the reference standard. The sensitivity for detecting a stenosis varied from 62 to 79% for MRA and from 76 to 94% for DSA, depending on the observer. The specificity for detecting a stenosis varied from 83 to 87% for MRA and from 83 to 97% for DSA. Using the criterion ''more than two stenoses in at least two separate vascular distributions'' to consider the examination as being true positive, the false-positive rates for MRA and DSA were comparable. MRA plays a role as the first angiographical examination in the diagnostic work-up of suspected cerebral vasculitis. When more than two stenoses in at least two separate vascular distributions are depicted on MRA, DSA is not expected to add a significant diagnostic contribution in a patient with suspected cerebral vasculitis. DSA remains necessary when MRA is normal or when less than three stenoses are seen. (orig.)

  3. Postradiation regional cerebral blood flow in primates

    International Nuclear Information System (INIS)

    Cockerham, L.G.; Cerveny, T.J.; Hampton, J.D.

    1986-01-01

    Early transient incapacitation (ETI) is the complete cessation of performance during the first 30 min after radiation exposure and performance decrement (PD) is a reduction in performance at the same time. Supralethal doses of radiation have been shown to produce a marked decrease in regional cerebral blood flow in primates concurrent with hypotension and a dramatic release of mast cell histamine. In an attempt to elucidate mechanisms underlying the radiation-induced ETI/PD phenomenon and the postradiation decrease in cerebral blood flow, primates were exposed to 100 Gy (1 Gy = 100 rads), whole-body, gamma radiation. Pontine and cortical blood flows were measured by hydrogen clearance, before and after radiation exposure. Systemic blood pressures were determined simultaneously. Systemic arterial histamine levels were determined preradiation and postradiation. Data obtained indicated that radiated animals showed a decrease in blood flow of 63% in the motor cortex and 51% in the pons by 10 min postradiation. Regional cerebral blood flow of radiated animals showed a slight recovery 20 min postradiation, followed by a fall to the 10 min nadir by 60 min postradiation. Immediately, postradiation systemic blood pressure fell 67% and remained at that level for the remainder of the experiment. Histamine levels in the radiated animals increased a hundredfold 2 min postradiation. This study indicates that regional cerebral blood flow decreases postradiation with the development of hypotension and may be associated temporally with the postradiation release of histamine

  4. Cerebral malformations without antenatal diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Girard, Nadine J. [Diagnostic Neuroradiology, Hopital Timone, Marseille (France)

    2010-06-15

    Cerebral malformations are usually described following the different steps in development. Disorders of neurulation (dysraphisms), or diverticulation (holoprosencephalies and posterior fossa cysts), and total commissural agenesis are usually diagnosed in utero. In contrast, disorders of histogenesis (proliferation-differentiation, migration, organization) are usually discovered in infants and children. The principal clinical symptoms that may be a clue to cerebral malformation include congenital hemiparesis, epilepsy and mental or psychomotor retardation. MRI is the imaging method of choice to assess cerebral malformations. (orig.)

  5. Ischemic Left Ventricular Perforation Covered by a Thrombus in a Patient Presenting with Cerebral Ischemia: Importance of Time-Sensitive Performance and Adequate Interpretation of Bedside Transthoracic Echography

    Directory of Open Access Journals (Sweden)

    A. J. Fischer

    2016-01-01

    Full Text Available If myocardial infarction remains silent, only clinical signs of complications may unveil its presence. Life-threatening complications include myocardial rupture, thrombus formation, or arterial embolization. In the presented case, a 76-year-old patient was admitted with left-sided hemiparesis. In duplex sonography, a critical stenosis of the right internal carotid artery was identified and initially but retrospectively incorrectly judged as the potential cause for ischemia. During operative thromboendarterectomy, arterial embolism of the right leg occurred coincidentally, more likely pointing towards a cardioembolic origin. Percutaneous interventions remained unsuccessful and local fibrinolysis was applied. Delayed bedside echocardiography by an experienced cardiologist demonstrated a discontinuity of the normal myocardial texture of the left ventricular apex together with an echodense, partly floating structure merely attached by a thin bridge not completely sealing the myocardial defect, accompanied by pericardial effusion. The patient was immediately transferred to emergency cardiac surgery with extirpation of the thrombus, aortocoronary bypass graft placement, and aneurysmectomy. This didactic case reveals decisive structural shortcomings in patient’s admission and triage processes and underlines, if performed timely and correctly, the value of transthoracic echocardiography as a noninvasive and cost-effective tool allowing immediate decision-making, which, in this case, led to the correct but almost fatally delayed diagnosis.

  6. Ischemic Left Ventricular Perforation Covered by a Thrombus in a Patient Presenting with Cerebral Ischemia: Importance of Time-Sensitive Performance and Adequate Interpretation of Bedside Transthoracic Echography.

    Science.gov (United States)

    Fischer, A J; Lebiedz, P; Wiaderek, M; Lichtenberg, M; Böse, D; Martens, S; Breuckmann, F

    2016-01-01

    If myocardial infarction remains silent, only clinical signs of complications may unveil its presence. Life-threatening complications include myocardial rupture, thrombus formation, or arterial embolization. In the presented case, a 76-year-old patient was admitted with left-sided hemiparesis. In duplex sonography, a critical stenosis of the right internal carotid artery was identified and initially but retrospectively incorrectly judged as the potential cause for ischemia. During operative thromboendarterectomy, arterial embolism of the right leg occurred coincidentally, more likely pointing towards a cardioembolic origin. Percutaneous interventions remained unsuccessful and local fibrinolysis was applied. Delayed bedside echocardiography by an experienced cardiologist demonstrated a discontinuity of the normal myocardial texture of the left ventricular apex together with an echodense, partly floating structure merely attached by a thin bridge not completely sealing the myocardial defect, accompanied by pericardial effusion. The patient was immediately transferred to emergency cardiac surgery with extirpation of the thrombus, aortocoronary bypass graft placement, and aneurysmectomy. This didactic case reveals decisive structural shortcomings in patient's admission and triage processes and underlines, if performed timely and correctly, the value of transthoracic echocardiography as a noninvasive and cost-effective tool allowing immediate decision-making, which, in this case, led to the correct but almost fatally delayed diagnosis.

  7. Molecular pathophysiology of cerebral edema

    Science.gov (United States)

    Gerzanich, Volodymyr; Simard, J Marc

    2015-01-01

    Advancements in molecular biology have led to a greater understanding of the individual proteins responsible for generating cerebral edema. In large part, the study of cerebral edema is the study of maladaptive ion transport. Following acute CNS injury, cells of the neurovascular unit, particularly brain endothelial cells and astrocytes, undergo a program of pre- and post-transcriptional changes in the activity of ion channels and transporters. These changes can result in maladaptive ion transport and the generation of abnormal osmotic forces that, ultimately, manifest as cerebral edema. This review discusses past models and current knowledge regarding the molecular and cellular pathophysiology of cerebral edema. PMID:26661240

  8. [Estimation of Time-Dependent microRNA Expression Patterns in Brain Tissue, Leukocytes, and Blood Plasma of Rats under Photochemically Induced Focal Cerebral Ischemia].

    Science.gov (United States)

    Gusar, V A; Timofeeva, A V; Zhanin, I S; Shram, S I; Pinelis, V G

    2017-01-01

    miRNA expression over different time periods (24 and 48 h) using the quantitative RT-PCR and deep sequencing has been evaluated in a model of photochemically induced thrombosis. A combination of two approaches allowed us to determine the miRNA expression patterns caused by ischemia. Nine miRNAs, including let-7f-5p, miR-221-3p, miR-21-5p, miR-30c-5p, miR-30a-3p, miR-223-3p, miR-23a-3p, miR-22-5p, and miR-99a-5p, were differentially expressed in brain tissue and leukocytes of rats 48 h after onset of ischemia. In addition, six miRNAs were differentially expressed in the brain tissue and blood plasma of rats 24 h after exposure, among which miR-145-3p and miR-375-3p were downregulated and miR-19a-3p, miR-92a-3p, miR-188-5p, and miR-532-5p were upregulated. In our opinion, miR-188-5p and miR-532-5p may be considered to be new potential markers of ischemic injury. The level of miRNA expression tended to increase 48 h after the onset of ischemia in brain tissue and leukocytes, which reflects not only the local response in brain tissue due to inflammation, vascular endothelial dysfunction, and disorders of the permeability of the blood-brain barrier, but also the systemic response of the organism to multifactor molecular processes induced by ischemic injury.

  9. Diagnosis of hemodynamic compromise in patients with chronic cerebral ischemia

    International Nuclear Information System (INIS)

    Kuroda, Satoshi; Sakuragi, Mitsugi; Motomiya, Mineo; Nakagawa, Tango; Mitsumori, Kenji; Tsuru, Mitsuo; Takigawa, Shugo; Kamiyama, Hiroyasu; Abe, Hiroshi.

    1990-01-01

    Tests using 133 Xe inhalation method and single photon emission computed tomography (SPECT) with acetazolamide (Diamox) were performed in 23 patients with chronic cerebral ischemia, before and after extracranial-intracranial bypass surgery or carotid-endarterectomy. All patients complained of TIA, RIND, or minor completed stroke. Cerebral angiography demonstrated severe stenosis or occlusion in the ipsilateral internal carotid artery or middle cerebral artery. Cerebral blood flow (CBF) was measured with 133 Xe SPECT, and was measured 15 minutes after intravenous administration of 10-12 mg/kg Diamox, which is known as a cerebral vasodilatory agent (Diamox test). Our results revealed that all patients could be divided into four types according to their resting rCBF and Diamox reactivity. The patients who had normal resting rCBF and normal Diamox reactivity (type 1) were considered to have well-developed collateral circulation and normal cerebral perfusion pressure (CPP) in spite of severe occlusive lesions in the carotid system. Moderate vasodilation due to reduced CPP was considered to occur in patients who had normal resting rCBF and decreased Diamox reactivity (type 2). The resting rCBF remained unchanged, but Diamox reactivity improved to normal after surgery in the patients of type 2, which indicated the improvement of CPP and the resolution of the autoregulatory vasodilation. Maximum vasodilation or dysautoregulation was considered to occur due to the inadequate collateral flow and the severely reduced CPP in patients whose findings revealed decrease in the resting rCBF and impaired Diamox reactivity (type 3). Remarkable improvement was seen in both resting rCBF and Diamox reactivity after surgery in the patients of type 3. In the patients who had decreased resting rCBF and normal Diamox reactivity (type 4), the decreased resting rCBF was considered to result from the reduction in metabolic demand because of irreversible ischemic neuronal damage. (J.P.N.)

  10. Relationship between blood uric and acute cerebral infarction

    International Nuclear Information System (INIS)

    Yin Zhanxia; Zhao Danyang

    2011-01-01

    Objective: To study the relationship between blood uric acid and acute cerebral infarction. Methods: The level of blood uric acid and prevalence of hyperuricemia (HUA) were compared in 360 patients with acute cerebral infarction and 300 patients without it. According to the level of blood uric acid, 360 acute cerebral infarction patients were divided into HUA and normouricemia (NUA) groups. Age, sex, body mass index (BMI), blood glucose and total cholesterol were compared between the HUA and NUA group. The degree of neurological functional defection was compared between the two groups when patients were attacked by acute cerebral infarction. After a recovery treatment, the neurological functional defection of the two groups was compared a second time. Results: (1)The average blood uric acid level and prevalence of HUA were higher in patients with acute cerebral infarction. (2) The BMI, blood glucose and total cholesterol were higher in HUA group than in NUA group. (3) The neurological functional defection was more serious in HUA group when patients were attacked by acute cerebral infarction and after a recovery treatment. Conclusion: Hyperuricemia is related to acute cerebral infarction. (authors)

  11. First circulating beam in the AA

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    On 3 July 1980, two years after project authorization, beam circulated for the first time in the AA. It was a 3.56 GeV/c proton test beam. We see an expecting crowd, minutes before the happy event. The persons are too numerous to name them all, but the 3 most prominent ones are at the centre (left to right): Roy Billinge (Joint AA Project Leader, with his hand on the control box), Eifionydd Jones (white shirt), Simon van der Meer (spiritus rector and Joint AA Project Leader). The first antiprotons were injected, made to circulate and cooled soon after, on 14 July 1980.

  12. Effects of acetazolamide on the micro- and macro-vascular cerebral hemodynamics: A diffuse optical and transcranial doppler ultrasound study

    OpenAIRE

    Zirak P.; Delgado-Mederos R.; Marti-Fabregas J.; Durduran T.

    2010-01-01

    Acetazolamide (ACZ) was used to stimulate the cerebral vasculature on ten healthy volunteers to assess the cerebral vasomotor reactivity (CVR). We have combined near infrared spectroscopy (NIRS), diffuse correlation spectroscopy (DCS) and transcranial Doppler (TCD) technologies to non-invasively assess CVR in real-time by measuring oxy- and deoxy-hemoglobin concentrations, using NIRS, local cerebral blood flow (CBF), using DCS, and blood flow velocity (CBFV) in the middle cerebral artery, usi...

  13. [Effect of Chinese drugs for activating blood circulation and removing blood stasis on carotid atherosclerosis and ischemic cerebrovascular events].

    Science.gov (United States)

    Lu, Yan; Li, Tao

    2014-03-01

    To explore the effect of Chinese drugs for activating blood circulation and removing blood stasis (CDABCRBS) on carotid atherosclerotic plaque and long-term ischemic cerebrovascular events. By using open and control method, effect of 4 groups of platelet antagonists, platelet antagonists + CDABCRBS, platelet antagonists +atorvastatin, platelet antagonists +atorvastatin +CDABCRBS on carotid atherosclerotic plaque and long-term ischemic cerebrovascular events of 90 cerebral infarction patients were analyzed. Through survival analysis, there was no statistical difference in the effect of the 4 interventions on the variation of carotid stenosis rates or ischemic cerebrovascular events (P > 0.05). The occurrence of ischemic cerebrovascular events could be postponed by about 4 months in those treated with platelet antagonists + CDABCRBS and platelet antagonists + atorvastatin +CDABCRBS. By multivariate Logistic analysis, age, hypertension, and clopidogrel were associated with stenosis of extracranial carotid arteries (P cerebrovascular accidents (P cerebrovascular events. CDABCRBS could effectively prolong the occurrence time of ischemic cerebrovascular events.

  14. A Means for the Scintigraphic Imaging of Regional Brain Dynamics. Regional Cerebral Blood Flow and Regional Cerebral Blood Volume

    Energy Technology Data Exchange (ETDEWEB)

    Potchen, E. J.; Bentley, R.; Gerth, W.; Hill, R. L.; Davis, D. O. [Washington University School Of Medicine, St. Louis, MO (United States)

    1969-05-15

    The use of freely diffusable inert radioactive gas as a washout indicator to measure regional cerebral blood flow has become a standardized kinetic procedure in many laboratories. Recent investigations with this technique have led us to conclude that we can reliably distinguish regional flow with perfusion against regional flow without perfusion from the early portion of the curve. Based on a detailed study of the early curve kinetics in patients with and without cerebral vascular disease we have defined the sampling duration necessary for application of the Anger gamma camera imaging process to regional changes in cerebral radioactivity. Using a standard camera and a small computer, a procedure has been developed and based upon entire field to determine the time of maximum height followed by analysis of the data in a matrix. This will permit a contour plot presentation of calculated regional cerebral blood flow in millilitres per 100 grams perfused brain per minute. In addition, we propose to augment this data by the display of regional non-perfusion blood flow versus regional cerebral flow with perfusion. Preliminary investigation on sampling duration, and Compton scattering were prerequisite to clinical scintigraphy of regional cerebral blood flow. In addition, the method of interface for the conventional Anger gamma camera to digital computers used in this procedure are discussed. Applications to further assess regional cerebral dynamics by scintigraphy are presented. (author)

  15. [Raman spectra of monkey cerebral cortex tissue].

    Science.gov (United States)

    Zhu, Ji-chun; Guo, Jian-yu; Cai, Wei-ying; Wang, Zu-geng; Sun, Zhen-rong

    2010-01-01

    Monkey cerebral cortex, an important part in the brain to control action and thought activities, is mainly composed of grey matter and nerve cell. In the present paper, the in situ Raman spectra of the cerebral cortex of the birth, teenage and aged monkeys were achieved for the first time. The results show that the Raman spectra for the different age monkey cerebral cortex exhibit most obvious changes in the regions of 1000-1400 and 2800-3000 cm(-1). With monkey growing up, the relative intensities of the Raman bands at 1313 and 2885 cm(-1) mainly assigned to CH2 chain vibrational mode of lipid become stronger and stronger whereas the relative intensities of the Raman bands at 1338 and 2932 cm(-1) mainly assigned to CH3 chain vibrational mode of protein become weaker and weaker. In addition, the two new Raman bands at 1296 and 2850 cm(-1) are only observed in the aged monkey cerebral cortex, therefore, the two bands can be considered as a character or "marker" to differentiate the caducity degree with monkey growth In order to further explore the changes, the relative intensity ratios of the Raman band at 1313 cm(-1) to that at 1338 cm(-1) and the Raman band at 2885 cm(-1) to that at 2 932 cm(-1), I1313/I1338 and I2885/I2932, which are the lipid-to-protein ratios, are introduced to denote the degree of the lipid content. The results show that the relative intensity ratios increase significantly with monkey growth, namely, the lipid content in the cerebral cortex increases greatly with monkey growth. So, the authors can deduce that the overmuch lipid is an important cause to induce the caducity. Therefore, the results will be a powerful assistance and valuable parameter to study the order of life growth and diagnose diseases.

  16. A computational model of the fetal circulation to quantify blood redistribution in intrauterine growth restriction.

    Directory of Open Access Journals (Sweden)

    Patricia Garcia-Canadilla

    2014-06-01

    Full Text Available Intrauterine growth restriction (IUGR due to placental insufficiency is associated with blood flow redistribution in order to maintain delivery of oxygenated blood to the brain. Given that, in the fetus the aortic isthmus (AoI is a key arterial connection between the cerebral and placental circulations, quantifying AoI blood flow has been proposed to assess this brain sparing effect in clinical practice. While numerous clinical studies have studied this parameter, fundamental understanding of its determinant factors and its quantitative relation with other aspects of haemodynamic remodeling has been limited. Computational models of the cardiovascular circulation have been proposed for exactly this purpose since they allow both for studying the contributions from isolated parameters as well as estimating properties that cannot be directly assessed from clinical measurements. Therefore, a computational model of the fetal circulation was developed, including the key elements related to fetal blood redistribution and using measured cardiac outflow profiles to allow personalization. The model was first calibrated using patient-specific Doppler data from a healthy fetus. Next, in order to understand the contributions of the main parameters determining blood redistribution, AoI and middle cerebral artery (MCA flow changes were studied by variation of cerebral and peripheral-placental resistances. Finally, to study how this affects an individual fetus, the model was fitted to three IUGR cases with different degrees of severity. In conclusion, the proposed computational model provides a good approximation to assess blood flow changes in the fetal circulation. The results support that while MCA flow is mainly determined by a fall in brain resistance, the AoI is influenced by a balance between increased peripheral-placental and decreased cerebral resistances. Personalizing the model allows for quantifying the balance between cerebral and peripheral

  17. Clinical significance of posterior cerebral artery stenosis/occlusion in moyamoya disease

    Energy Technology Data Exchange (ETDEWEB)

    Kuroda, Satoshi; Ishikawa, Tatsuya; Iwasaki, Yoshinobu [Hokkaido Univ., Sapporo (Japan). Graduate School of Medicine; Houkin, Kiyohiro [Sapporo Medical Univ. (Japan)

    2002-12-01

    The present study was aimed at clarifying the clinical significance of posterior cerebral artery (PCA) stenosis/occlusion in pediatric and adult moyamoya disease. This study included a total of 132 patients (52 children and 80 adults) who were diagnosed as by cerebral angiography having moyamoya disease. CT or MRI was performed to examine the location of cerebral infarction in all subjects. Cerebral blood flow and vasoreactivity to acetazolamide were measured in 80 patients before surgery, using single photon emission computed tomography (SPECT). Three-dimensional MR angiography (3D-MRA) was repeated in 32 pediatric patients after surgery in order to clarify the natural course of the PCA stenosis/occlusion. Of 264 sides in 132 patients, PCA stenosis/occlusion was observed in 50 sides of 40 patients (30.3%). Its incidence was significantly higher in ischemic-type patients than in hemorrhagic-type and asymptomatic patients, and was higher in patients in the advanced stage of the disease. The hemisphere ipsilateral to PCA stenosis/occlusion had higher incidence of ischemic symptoms, cerebral infarction, and impaired cerebral hemodynamics. Transient ischemic attack (TIA) (hemianopsia) or cerebral infarction in the occipital lobe was noted in 4 (10%) of 40 patients during follow-up periods after bypass surgery for anterior circulation. Of 32 pediatric patients, none showed progression of PCA stenosis on 3D-MRA during follow-up periods. The present study showed that the involvement of PCA could increase the risk of TIA and/or cerebral infarction in both anterior and posterior circulation areas, suggesting that the PCA plays an important collateral role in moyamoya disease. (author)

  18. Cerebral Amyloid Angiopathy

    Directory of Open Access Journals (Sweden)

    Mahmut Edip Gürol

    2009-03-01

    Full Text Available Cerebral amyloid angiopathy (CAA is characterized by the accumulation of amyloid beta-peptides (Ab in the walls of leptomeningeal arteries, arterioles, and veins. Despite the fact that these pathological changes were first described in 1909, major advancement in our understanding of the clinicoradiological manifestations, neurobiology, and course of CAA has occurred only during the last 30 years. No significant associations have been shown between CAA and other systemic/visceral amyloidoses or vascular risk factors, including hypertension. CAA is well known as the most common cause of spontaneous and anticoagulant-related lobar parenchymal ICH in the elderly. It also causes lobar cerebral microbleeds (CMBs, small dot-like dark susceptibility artifacts visible with gradient recalled echo (GRE-magnetic resonance imaging (MRI. CMBs are important markers of disease severity and predictors of CAA progression. Amyloid angiopathy is also a common cause of ischemic microvascular white matter disease (WMD and deep cerebral infarctions. Such WMD is defined as subcortical and periventricular white matter changes without obvious infarction, as well as a dark appearance on computerized tomography (CT and a bright appearance on fluid attenuated inversion recovery (FLAIR-MRI. CAA-related vascular dysfunction, with its hemorrhagic and ischemic complications, is a recognized contributor to vascular cognitive impairment in the elderly, an independent effect that is synergistically increased by Alzheimer pathologies, such as plaques and tangles. A set of clinicoradiological criteria was established for the accurate diagnosis of CAA. According to the Boston Criteria, patients aged 55 years and older with multiple hemorrhages (on CT or GRE-MRI restricted to the lobar, cortical, or corticosubcortical regions (cerebellar hemorrhage allowed are diagnosed as probable CAA when no other etiology is found; a single hemorrhage in the same region is classified as possible

  19. Interfaces para control cerebral

    OpenAIRE

    Spinelli, Enrique Mario

    2000-01-01

    La función de una interfaz para control cerebral basada en señales de electroencefalograma (EEG), en forma general denominada BCI (Brain control Interface), es establecer un enlace directo entre el cerebro y una máquina, sin utilizar acciones motoras directas. Una BCI permite realizar operaciones simples a partir de la interpretación de las señales de EEG. Su desarrollo está principalmente orientado hacia la ayuda a personas con discapacidades motoras severas, que poseen deterioros en el sist...

  20. Techniques in cerebral protection.

    Science.gov (United States)

    Fanelli, Fabrizio; Bezzi, Mario; Boatta, Emanuele; Passariello, Roberto

    2006-10-01

    Carotid angioplasty and stenting is a valid alternative option to conventional carotid endarterectomy in the treatment of carotid artery stenosis. During the stenting process, however, distal embolization can occur with neurological consequences. To avoid this, cerebral protection devices have been introduced. Three principal types of protection system have been developed: distal balloon occlusion, distal filters and proximal protection with or without reversal of flow. As protection devices became the focus of interest by manufactures and physicians, several trials are going on worldwide to analyze the characteristics of each of them and to evaluate their efficacy to reduce the rate of distal embolization.

  1. Regional cerebral blood flow measurement using a scintillation camera

    International Nuclear Information System (INIS)

    Heiss, W.D.

    1979-01-01

    A scintillation camera connected to auxillary equipment with off-line data processing or connected to an on-line dedicated computer system permits measurement of hemispheric and regional cerebral blood flow. Reliable flow values are obtained from regions limited in size by spatial resolution and the count rates achieved. Flow measurements obtained with the camera are able to resolve inhomogeneities of cerebral circulation in normal subjects. In a variety of clinical conditions, the localization, severity and extent of flow alterations are shown. Results of flow measurements in individual cases elucidate the pathogenesis of neurologic deficits, quantify the damage to the brain, indicate therapeutic measures of potential value and permit an estimation of the further clinical course. With restricted spatial resolution, flow measurements after intravenous 133 Xe injection are also feasible

  2. Increased Cerebral Water Content in Hemodialysis Patients

    OpenAIRE

    Reetz, Kathrin; Abbas, Zaheer; Eitner, Frank; Gross, Theresa; Schulz, Jörg Bernhard; Floege, Jürgen; Shah, N. J.; Costa, Ana Sofia; Gras, Vincent; Tiffin-Richards, Frances; Mirzazade, Shahram; Holschbach, Bernhard; Frank, Rolf Dario; Vassiliadou, Athina; Krüger, Thilo

    2015-01-01

    Little information is available on the impact of hemodialysis on cerebral water homeostasis and its distribution in chronic kidney disease. We used a neuropsychological test battery, structural magnetic resonance imaging (MRI) and a novel technique for quantitative measurement of localized water content using 3T MRI to investigate ten hemodialysis patients (HD) on a dialysis-free day and after hemodialysis (2.4±2.2 hours), and a matched healthy control group with the same time interval. Neuro...

  3. Regional cerebral flows in hypertensive patients

    International Nuclear Information System (INIS)

    Britton, K.E.; Granowska, M.; Lee, T.Y.; Nimmon, C.C.; Rutland, M.

    1978-01-01

    The aim of this study is to develop a method for assessing the natural history of cerebrovascular disease in patients with hypertension in order that the effects of controlling hypertension may be judged. By developing a quantitative noninvasive method for measuring regional cerebral flow and internal carotid appearance times it is hoped that drugs intended to inhibit the continued formation of atheroma and drugs intended to aid the dissolution of atheroma, may be objectively evaluated. (Auth.)

  4. Cerebral aneurysms – an audit

    African Journals Online (AJOL)

    Enrique

    Abstract. We performed an audit to determine the profile of cerebral aneurysms at the Universitas Hospital Bloem- fontein, the only government hospital with a vascular suite in the Free State and Northern Cape area. Two hun- dred and twenty-three government patients, diagnosed with cerebral aneurysms during the period.

  5. Circulation Systems Past and Present

    Directory of Open Access Journals (Sweden)

    Maurice J. Freedman

    1981-01-01

    Full Text Available A review of the development of circulation systems shows two areas of change. The librarian's perception of circulation control has shifted from a broad service orientation to a narrow record-keeping approach and recently back again. The technological development of circulation sys-tems has evolved from manual systems to the online systems of today. The trade-offs and deficiencies of earlier systems in relation to the comprehensive services made possible by the online computer are detailed.

  6. Electroacupuncture improves neurovascular unit reconstruction by promoting collateral circulation and angiogenesis

    Directory of Open Access Journals (Sweden)

    Lei Shi

    2017-01-01

    Full Text Available Acupuncture at Shuigou (GV26 shows good clinical efficacy for treating stroke, but its mechanism remains poorly understood. In this study, a cerebral infarction model of ischemia/reperfusion injury received electroacupuncture at GV26 (15 Hz and 1 mA, continuous wave [biphasic pulses], for 5 minutes. Electroacupuncture effectively promoted regional cerebral blood flow on the infarct and non-infarct sides, increased infarct lesions, lectin, and number of blood vessels, upregulated von Willebrand factor and cell proliferation marker Ki67 expression, and diminished neurological severity score. These findings confirm that electroacupuncture at GV26 promotes establishment of collateral circulation and angiogenesis, and improves neurological function.

  7. Therapeutic interventions in cerebral palsy.

    Science.gov (United States)

    Patel, Dilip R

    2005-11-01

    Various therapeutic interventions have been used in the management of children with cerebral palsy. Traditional physiotherapy and occupational therapy are widely used interventions and have been shown to be of benefit in the treatment of cerebral palsy. Evidence in support of the effectiveness of the neurodevelopmental treatment is equivocal at best. There is evidence to support the use and effectiveness of neuromuscular electrical stimulation in children with cerebral palsy. The effectiveness of many other interventions used in the treatment of cerebral palsy has not been clearly established based on well-controlled trials. These include: sensory integration, body-weight support treadmill training, conductive education, constraint-induced therapy, hyperbaric oxygen therapy, and the Vojta method. This article provides an overview of salient aspects of popular interventions used in the management of children with cerebral palsy.

  8. The ocean circulation inverse problem

    National Research Council Canada - National Science Library

    Wunsch, C

    1996-01-01

    .... This book addresses the problem of inferring the state of the ocean circulation, understanding it dynamically, and even forecasting it through a quantitative combination of theory and observation...

  9. Mechanism of the re-buildup phenomenon in moyamoya disease; Analysis of local cerebral hemodynamics with intra-arterial digital subtraction angiography

    Energy Technology Data Exchange (ETDEWEB)

    Touho, Hajime; Karasawa, Jun; Shishido, Hisashi; Morisako, Toshitaka; Yamada, Keisuke; Nagai, Shigeki; Shibamoto, Kenji [Osaka Neurological Institute, Osaka (Japan)

    1990-10-01

    The authors investigated the mechanism of the re-buildup phenomenon on electroencephalogram in 14 patients of moyamoya disease with superficial temporal artery-middle cerebral artery anastomosis. Visualization of the lateral view of the common carotid angiography was performed with intra-arterial digital subtraction angiography (IA-DSA), using a 4/sec x 3 sec + 2/sec x 5 sec + 1/sec x 5 sec film sequence. The catheter tip was inserted into C5/6 level and 250 mgl/ml of iopamidol was used as the contrast agent; 6 ml in total was injected over 1.5 seconds. Circulation times of the common carotid artery (C{sub 3} portion)-ascending parietal vein ({delta}TTP{sub s}) and common carotid artery-internal cerebral vein ({delta}TTP{sub D}) were measured before hyperventilation (HV), immediately after HV, and 3 minutes after HV during pre- and postoperative periods. {delta}TTP{sub D} in the preoperative period was prolonged by HV and was normalized at 3 minutes after HV but {delta}TTP{sub S} were prolonged immediately after and 3 minutes after HV. In the postoperative period, however, these values did not change significantly immediately after and 3 minutes after HV. These findings indicate that delayed cerebral blood flow response to HV is a pathogenetic factor of the re-buildup phenomenon in moyamoya disease. (author).

  10. Cerebral imaging in pediatrics

    International Nuclear Information System (INIS)

    Gordon, I.

    1998-01-01

    Radioisotope brain imaging has focused mainly on regional cerebral blood flow (rCBF). However the use of ligand which go to specific receptor sites is being introduced in pediatrics, mainly psychiatry. rCBF is potentially available in many institutions, especially with the availability of multi-headed gamma cameras. The use of this technique in pediatrics requires special attention to detail in the manner of data acquisition and handling the child. The interpretation of the rCBF study in a child requires knowledge of normal brain maturation. The major clinical use in pediatrics is epilepsy because of the advances in surgery and the frequency of complex partial seizures. Other indications in pediatric neurology include brain death, acute neurological loss including stroke, language disorders, cerebral palsy, hypertension due to renovascular disease, traumatic brain injury and migraine. There are pediatric physiological conditions in which rCBF has been undertaken, these include anorexia nervosa, autism, Gilles de la Tourette syndrome (GTS) and attention deficit disorder-hyperactivity (ADHD). Research using different ligands to specific receptor sites will also be reviewed in pediatrics

  11. Cerebral imaging in pediatrics

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, I [London, Great Ormond Street Hospital for Children (United Kingdom)

    1998-06-01

    Radioisotope brain imaging has focused mainly on regional cerebral blood flow (rCBF). However the use of ligand which go to specific receptor sites is being introduced in pediatrics, mainly psychiatry. rCBF is potentially available in many institutions, especially with the availability of multi-headed gamma cameras. The use of this technique in pediatrics requires special attention to detail in the manner of data acquisition and handling the child. The interpretation of the rCBF study in a child requires knowledge of normal brain maturation. The major clinical use in pediatrics is epilepsy because of the advances in surgery and the frequency of complex partial seizures. Other indications in pediatric neurology include brain death, acute neurological loss including stroke, language disorders, cerebral palsy, hypertension due to renovascular disease, traumatic brain injury and migraine. There are pediatric physiological conditions in which rCBF has been undertaken, these include anorexia nervosa, autism, Gilles de la Tourette syndrome (GTS) and attention deficit disorder-hyperactivity (ADHD). Research using different ligands to specific receptor sites will also be reviewed in pediatrics.

  12. Cerebral cartography and connectomics.

    Science.gov (United States)

    Sporns, Olaf

    2015-05-19

    Cerebral cartography and connectomics pursue similar goals in attempting to create maps that can inform our understanding of the structural and functional organization of the cortex. Connectome maps explicitly aim at representing the brain as a complex network, a collection of nodes and their interconnecting edges. This article reflects on some of the challenges that currently arise in the intersection of cerebral cartography and connectomics. Principal challenges concern the temporal dynamics of functional brain connectivity, the definition of areal parcellations and their hierarchical organization into large-scale networks, the extension of whole-brain connectivity to cellular-scale networks, and the mapping of structure/function relations in empirical recordings and computational models. Successfully addressing these challenges will require extensions of methods and tools from network science to the mapping and analysis of human brain connectivity data. The emerging view that the brain is more than a collection of areas, but is fundamentally operating as a complex networked system, will continue to drive the creation of ever more detailed and multi-modal network maps as tools for on-going exploration and discovery in human connectomics. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  13. Cerebral Gluconeogenesis and Diseases

    Science.gov (United States)

    Yip, James; Geng, Xiaokun; Shen, Jiamei; Ding, Yuchuan

    2017-01-01

    The gluconeogenesis pathway, which has been known to normally present in the liver, kidney, intestine, or muscle, has four irreversible steps catalyzed by the enzymes: pyruvate carboxylase, phosphoenolpyruvate carboxykinase, fructose 1,6-bisphosphatase, and glucose 6-phosphatase. Studies have also demonstrated evidence that gluconeogenesis exists in brain astrocytes but no convincing data have yet been found in neurons. Astrocytes exhibit significant 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 activity, a key mechanism for regulating glycolysis and gluconeogenesis. Astrocytes are unique in that they use glycolysis to produce lactate, which is then shuttled into neurons and used as gluconeogenic precursors for reduction. This gluconeogenesis pathway found in astrocytes is becoming more recognized as an important alternative glucose source for neurons, specifically in ischemic stroke and brain tumor. Further studies are needed to discover how the gluconeogenesis pathway is controlled in the brain, which may lead to the development of therapeutic targets to control energy levels and cellular survival in ischemic stroke patients, or inhibit gluconeogenesis in brain tumors to promote malignant cell death and tumor regression. While there are extensive studies on the mechanisms of cerebral glycolysis in ischemic stroke and brain tumors, studies on cerebral gluconeogenesis are limited. Here, we review studies done to date regarding gluconeogenesis to evaluate whether this metabolic pathway is beneficial or detrimental to the brain under these pathological conditions. PMID:28101056

  14. Cerebral Gluconeogenesis and Diseases.

    Science.gov (United States)

    Yip, James; Geng, Xiaokun; Shen, Jiamei; Ding, Yuchuan

    2016-01-01

    The gluconeogenesis pathway, which has been known to normally present in the liver, kidney, intestine, or muscle, has four irreversible steps catalyzed by the enzymes: pyruvate carboxylase, phosphoenolpyruvate carboxykinase, fructose 1,6-bisphosphatase, and glucose 6-phosphatase. Studies have also demonstrated evidence that gluconeogenesis exists in brain astrocytes but no convincing data have yet been found in neurons. Astrocytes exhibit significant 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 activity, a key mechanism for regulating glycolysis and gluconeogenesis. Astrocytes are unique in that they use glycolysis to produce lactate, which is then shuttled into neurons and used as gluconeogenic precursors for reduction. This gluconeogenesis pathway found in astrocytes is becoming more recognized as an important alternative glucose source for neurons, specifically in ischemic stroke and brain tumor. Further studies are needed to discover how the gluconeogenesis pathway is controlled in the brain, which may lead to the development of therapeutic targets to control energy levels and cellular survival in ischemic stroke patients, or inhibit gluconeogenesis in brain tumors to promote malignant cell death and tumor regression. While there are extensive studies on the mechanisms of cerebral glycolysis in ischemic stroke and brain tumors, studies on cerebral gluconeogenesis are limited. Here, we review studies done to date regarding gluconeogenesis to evaluate whether this metabolic pathway is beneficial or detrimental to the brain under these pathological conditions.

  15. Fort St. Vrain circulator operating experience

    Energy Technology Data Exchange (ETDEWEB)

    Brey, H. L.

    1988-08-15

    Fort St. Vrain, on the system of Public Service Company of Colorado, is the only high-temperature gas-cooled power reactor in the United States. Four helium circulators are utilized in this plant to transfer heat from the reactor to the steam generators. These unique machines have a single stage axial flow helium compressor driven by a single stage steam turbine. A single stage water driven (pelton wheel) turbine is the back-up drive utilizing either feed water, condensate, or fire water as the driving fluid. Developmental testing of the circulators was accomplished prior to installation into Fort St. Vrain. A combined machine operating history of approximately 250,000 hours has shown these machines to be of conservative design and proven mechanical integrity. However, many problems have been encountered in operating the complex auxiliaries which are necessary for successful circulator and plant operation. It has been 15 years since initial installation of the circulators occurred at Fort St. Vrain. During this time, a number of significant issues had to be resolved dealing specifically with machine performance. These events include cavitation damage of the pelton wheels during the initial plant hot functional testing, cracks in the water turbine buckets and cervic coupling, static shutdown seal bellows failure, and, most recently, degradation of components within the steam drive assembly. Unreliable operation particularly with the circulator auxiliaries has been a focus of attention by Public Service Company of Colorado. Actions to replace or significantly modify the existing circulators and their auxiliaries are currently awaiting decisions concerning the long-term future of the Fort St. Vrain plant. (author). 10 refs, 7 figs, 2 tabs.

  16. Fort St. Vrain circulator operating experience

    International Nuclear Information System (INIS)

    Brey, H.L.

    1988-01-01

    Fort St. Vrain, on the system of Public Service Company of Colorado, is the only high-temperature gas-cooled power reactor in the United States. Four helium circulators are utilized in this plant to transfer heat from the reactor to the steam generators. These unique machines have a single stage axial flow helium compressor driven by a single stage steam turbine. A single stage water driven (pelton wheel) turbine is the back-up drive utilizing either feed water, condensate, or fire water as the driving fluid. Developmental testing of the circulators was accomplished prior to installation into Fort St. Vrain. A combined machine operating history of approximately 250,000 hours has shown these machines to be of conservative design and proven mechanical integrity. However, many problems have been encountered in operating the complex auxiliaries which are necessary for successful circulator and plant operation. It has been 15 years since initial installation of the circulators occurred at Fort St. Vrain. During this time, a number of significant issues had to be resolved dealing specifically with machine performance. These events include cavitation damage of the pelton wheels during the initial plant hot functional testing, cracks in the water turbine buckets and cervic coupling, static shutdown seal bellows failure, and, most recently, degradation of components within the steam drive assembly. Unreliable operation particularly with the circulator auxiliaries has been a focus of attention by Public Service Company of Colorado. Actions to replace or significantly modify the existing circulators and their auxiliaries are currently awaiting decisions concerning the long-term future of the Fort St. Vrain plant. (author). 10 refs, 7 figs, 2 tabs

  17. Development of tailored real-time RT-PCR assays for the detection and differentiation of serotype O, A and Asia-1 foot-and-mouth disease virus lineages circulating in the Middle East

    DEFF Research Database (Denmark)

    Reid, Scott M.; Mioulet, Valerie; Knowles, Nick J.

    2014-01-01

    transcription polymerase chain reaction (rRT-PCR) assays using primer/probe sets designed from the VP1 coding region of the virus genomes were developed for the specific detection of serotype O, A and Asia-1 FMD viruses (FMDVs) circulating in the Middle East. These assays were evaluated using representative...... by the generic rRT-PCR diagnostic assays but negative by virus isolation and antigen-detection ELISA which would otherwise have to be serotyped by nucleotide sequencing. A similar approach could be used to develop serotyping assays for FMDV strains circulating in other regions of the world....

  18. Genetic Dissection of the Canq1 Locus Governing Variation in Extent of the Collateral Circulation

    Science.gov (United States)

    Wang, Shiliang; Zhang, Hua; Wiltshire, Tim; Sealock, Robert; Faber, James E.

    2012-01-01

    Background Native (pre-existing) collaterals are arteriole-to-arteriole anastomoses that interconnect adjacent arterial trees and serve as endogenous bypass vessels that limit tissue injury in ischemic stroke, myocardial infarction, coronary and peripheral artery disease. Their extent (number and diameter) varies widely among mouse strains and healthy humans. We previously identified a major quantitative trait locus on chromosome 7 (Canq1, LOD = 29) responsible for 37% of the heritable variation in collateral extent between C57BL/6 and BALB/c mice. We sought to identify candidate genes in Canq1 responsible for collateral variation in the cerebral pial circulation, a tissue whose strain-dependent variation is shared by similar variation in other tissues. Methods and Findings Collateral extent was intermediate in a recombinant inbred line that splits Canq1 between the C57BL/6 and BALB/c strains. Phenotyping and SNP-mapping of an expanded panel of twenty-one informative inbred strains narrowed the Canq1 locus, and genome-wide linkage analysis of a SWRxSJL-F2 cross confirmed its haplotype structure. Collateral extent, infarct volume after cerebral artery occlusion, bleeding time, and re-bleeding time did not differ in knockout mice for two vascular-related genes located in Canq1, IL4ra and Itgal. Transcript abundance of 6 out of 116 genes within the 95% confidence interval of Canq1 were differentially expressed >2-fold (p-valuecollateral formation. Conclusions These findings refine the Canq1 locus and identify several genes as high-priority candidates important in specifying native collateral formation and its wide variation. PMID:22412848

  19. Dynamic CT scan in cerebral infarction

    International Nuclear Information System (INIS)

    Kobayashi, Shigeki; Oka, Nobuo; Mitsuhashi, Hiromitsu

    1984-01-01

    Forty-two dynamic CT studies were performed on 27 patients with cerebral infarction (11 to 75 years of age), and perfusion patterns of low density areas on plain CT were evaluated. The initial studies were performed 1.5 hours to 60 days after acute onset. The following results were obtained. 1) The perfusion pattern in the low density area on plain CT varies among patients at any periods after onset, ranging from absent perfusion pattern to hyperfusion pattern. No consisitent perfusion pattern was obtained at any given time after onset. 2) Repeat dynamic CT revealed that the perfusion pattern in the low density area changed with time variously. 3) The perfusion pattern or change of perfusion pattern did not correlate with outcome of the patient. 4) At an acute stage, when no abnormal findings were obtained on plain CT, dynamic CT revealed abnormal perfusion pattern, enabling early diagnosis of cerebral infarction and estimation of blood perfusion in the infarcted area. In determining the treatment for the cerebral infarction at an acute stage, it is important to know the condition of the blood perfusion in the infarcted area. For the patients in whom recanalization has already taken place, mannitol or steroid might be effective, providing protection against severe brain edema and hemorrhagic infarction. On the other hand, if recanalization has not taken place, revascularization therapy might be worth trying within 6 hours since the onset. It has been said that ischemic brain damage may not be reversed by the revascularization after 6 hours. Dynamic CT is safe, less invasive, convenient and very useful for early diagnosis of the cerebral infarction and determination of the treatment at the acute stage. (J.P.N.)

  20. Severe Plasmodium falciparum malaria is associated with circulating ultra-large von Willebrand multimers and ADAMTS13 inhibition.

    LENUS (Irish Health Repository)

    Larkin, Deirdre

    2009-03-01

    Plasmodium falciparum infection results in adhesion of infected erythrocytes to blood vessel endothelium, and acute endothelial cell activation, together with sequestration of platelets and leucocytes. We have previously shown that patients with severe infection or fulminant cerebral malaria have significantly increased circulatory levels of the adhesive glycoprotein von Willebrand factor (VWF) and its propeptide, both of which are indices of endothelial cell activation. In this prospective study of patients from Ghana with severe (n = 20) and cerebral (n = 13) P. falciparum malaria, we demonstrate that increased plasma VWF antigen (VWF:Ag) level is associated with disproportionately increased VWF function. VWF collagen binding (VWF:CB) was significantly increased in patients with cerebral malaria and severe malaria (medians 7.6 and 7.0 IU\\/ml versus 1.9 IU\\/ml; p<0.005). This increased VWF:CB correlated with the presence of abnormal ultra-large VWF multimers in patient rather than control plasmas. Concomitant with the increase in VWF:Ag and VWF:CB was a significant persistent reduction in the activity of the VWF-specific cleaving protease ADAMTS13 (approximately 55% of normal; p<0.005). Mixing studies were performed using P. falciparum patient plasma and normal pooled plasma, in the presence or absence of exogenous recombinant ADAMTS13. These studies demonstrated that in malarial plasma, ADAMTS13 function was persistently inhibited in a time-dependent manner. Furthermore, this inhibitory effect was not associated with the presence of known inhibitors of ADAMTS13 enzymatic function (interleukin-6, free haemoglobin, factor VIII or thrombospondin-1). These novel findings suggest that severe P. falciparum infection is associated with acute endothelial cell activation, abnormal circulating ULVWF multimers, and a significant reduction in plasma ADAMTS13 function which is mediated at least in part by an unidentified inhibitor.

  1. Neuroprotection by inhibiting the c-Jun N-terminal kinase pathway after cerebral ischemia occurs independently of interleukin-6 and keratinocyte-derived chemokine (KC/CXCL1 secretion

    Directory of Open Access Journals (Sweden)

    Benakis Corinne

    2012-04-01

    Full Text Available Abstract Background Cerebral ischemia is associated with the activation of glial cells, infiltration of leukocytes and an increase in inflammatory mediators in the ischemic brain and systemic circulation. How this inflammatory response influences lesion size and neurological outcome remains unclear. D-JNKI1, an inhibitor of the c-Jun N-terminal kinase pathway, is strongly neuroprotective in animal models of stroke. Intriguingly, the protection mediated by D-JNKI1 is high even with intravenous administration at very low doses with undetectable drug levels in the brain, pointing to a systemic mode of action, perhaps on inflammation. Findings We evaluated whether D-JNKI1, administered intravenously 3 h after the onset of middle cerebral artery occlusion (MCAO, modulates secretion of the inflammatory mediators interleukin-6 and keratinocyte-derived chemokine in the plasma and from the spleen and brain at several time points after MCAO. We found an early release of both mediators in the systemic circulation followed by an increase in the brain and went on to show a later systemic increase in vehicle-treated mice. Release of interleukin-6 and keratinocyte-derived chemokine from the spleen of mice with MCAO was not significantly different from sham mice. Interestingly, the secretion of these inflammatory mediators was not altered in the systemic circulation or brain after successful neuroprotection with D-JNKI1. Conclusions We demonstrate that neuroprotection with D-JNKI1 after experimental cerebral ischemia is independent of systemic and brain release of interleukin-6 and keratinocyte-derived chemokine. Furthermore, our findings suggest that the early systemic release of interleukin-6 and keratinocyte-derived chemokine may not necessarily predict an unfavorable outcome in this model.

  2. Cerebral toxoplasmosis in AIDS

    International Nuclear Information System (INIS)

    Christ, F.; Steudel, H.; Klotz, D.; Bonn Univ.; Bonn Univ.

    1986-01-01

    Since 1982 (Hauser and co-workers), literature has reported focal cerebral tissue charges in AIDS patients whose diagnosis was unclear at first but which could be identified finally as florid toxoplasmosis encephalitis by biopsy and autopsy. It was found that the value of otherwise reliable serological tests (KBR, Sabin-Feldmann tests, etc.) is questionable in patients with severely impaired or incompetent immune systems, and, in particular, that a negative or uncharacteristic test result may not preclude any opportunistic infection process. Furthermore, isolation of Toxoplasma gondii or specific antibodies from the cerebrospinal fluid will be successful in exceptional cases only. In patients with AIDS or lymphadenopathy syndrome, the differential diagnosis will have to include - first and foremost - reactivated toxoplasma infection (not newly acquired, as a rule) if central neurological symptoms occur. (orig.) [de

  3. Cerebral white matter hypoplasia

    International Nuclear Information System (INIS)

    Dietrich, R.B.; Shields, W.D.; Sankar, R.

    1990-01-01

    This paper demonstrates the MR imaging findings in children with cerebral white matter hypoplasia (CWMH). The MR studies of four children, aged 3-7 y (mean age, 2.3 y) with a diagnosis of CWMH were reviewed. In all cases multiplanar T1-weighted and T2-weighted spin-echo images were obtained. All children had similar histories of severe developmental delay and nonprogressive neurologic deficits despite normal gestational and birth histories. In two cases there was a history of maternal cocaine abuse. Autopsy correlation was available in one child. The MR images of all four children demonstrated diffuse lack of white matter and enlarged ventricles but normal-appearing gray matter. The corpus callosum, although completely formed, was severely thinned. There was no evidence of gliosis or porencephaly, and the distribution of myelin deposition was normal for age in all cases. Autopsy finding in one child correlated exactly with the MR finding

  4. Multiple cerebral hydatid cysts

    Energy Technology Data Exchange (ETDEWEB)

    Banzo, J.; Pina, J.I.; Abos, M.D.; Rios, G.; Garcia, D.; Marin, F.; Diaz, F.J.

    1984-12-01

    A 39-year-old woman was admitted to hospital with headaches, vomiting, psychic impairment and diplopia. Three hydatid cysts of the lung had been previously removed. An avascular mass in the left hemisphere with left-to-right displacement of the anterior cerebral arteries was noted during a brain angioscintigraphy. A cerebralthrombosis (CT) brain scan showed two cystic lesions situated in the left-frontal and occipital regions. A CT abdominal scan showed multiple cysts in the liver, spleen and both kidneys. At operation, two brain cysts were totally extirpated without rupture. The definite pathological diagnosis was secondry hydatid cysts. The headaches, vomiting and diplopia were persistent in the post-operative period. Seven days after the operation, a CT brain scan showed an infratenrorial cyst. The patient rejected any surgical intervention.

  5. Natural Circulation with Boiling

    Energy Technology Data Exchange (ETDEWEB)

    Mathisen, R P

    1967-09-15

    A number of parameters with dominant influence on the power level at hydrodynamic instability in natural circulation, two-phase flow, have been studied experimentally. The geometrical dependent quantities were: the system driving head, the boiling channel and riser dimensions, the single-phase as well as the two phase flow restrictions. The parameters influencing the liquid properties were the system pressure and the test section inlet subcooling. The threshold of instability was determined by plotting the noise characteristics in the mass flow records against power. The flow responses to artificially obtained power disturbances at instability conditions were also measured in order to study the nature of hydrodynamic instability. The results presented give a review over relatively wide ranges of the main parameters, mainly concerning the coolant performance in both single and parallel boiling channel flow. With regard to the power limits the experimental results verified that the single boiling channel performance was intimately related to that of the parallel channels. In the latter case the additional inter-channel factors with attenuating effects were studied. Some optimum values of the parameters were observed.

  6. Diffusion-weighted MRI in acute cerebral stroke

    Energy Technology Data Exchange (ETDEWEB)

    Takayama, Hideichi; Kobayashi, Masahito; Suga, Sadao; Kawase, Takeshi; Nagasawa, Masakazu; Sadanaga, Humiko; Okamura, Miyuki; Kanai, Yoshihiro; Mihara, Ban [Mihara Memorial Hospital, Isezaki, Gunma (Japan)

    1999-03-01

    Diffusion-weighted MRI has been demonstrated to be valuable in the assessment of cerebral stroke. Recent advance in MR systems of hardware with larger maximum gradient amplitude and faster imaging strategies, such as EPI, has made it possible to acquire whole brain diffusion-weighted imaging (DWI) in less that one minute. The purposes of this study are to evaluate clinical usefulness of DWI and to clarify pitfalls in the diagnosis of acute cerebral stroke. Seventeen patients with 18 ischemic lesions were studied. DWI were taken with 1.5 Tesla MRI (Magnetom Vision, Siemens, Germany) using EPI sequence. Fifteen lesions out of them (3 in cerebral cortex, 9 in basal ganglia/deep white matter and 3 in cerebellum) were studied serially at various times up to 147 days. Acute cerebral infarction was seen clearly as an area of hyperintensity with DWI and as hypointensity in apparent diffusion coefficient (ADC) maps which are indicative of decreased diffusion. DWI detected areas of hyperintense acute infarcts, as early as 2.5 hours after onset, which were not visualized on T{sub 2}-weighted image (T2WI). The lesion of cerebral infarction became isointense in ADC maps at 14-28 days after onset, whereas with DWI it became isointense at about 2 months. Because ADC changed earlier than DWI, ADC maps were useful for differentiate acute from nonacute lesion in cases of recurrent stroke within a short period. In a patient with transient global amnesia for 7 hours, DWI did not show any lesion at 8 hours. In terms of cerebral hemorrhage, lesions were seen as area of hyperintensity in DWI at 3 days and were not distinguishable from that of infarct. Despite limitations in the diagnosis of transient ischemia and cerebral hemorrhage, DWI is a useful technique for early detection of cerebral infarction, especially within the first 6 hours after stroke onset. (author)

  7. Diffusion-weighted MRI in acute cerebral stroke

    International Nuclear Information System (INIS)

    Takayama, Hideichi; Kobayashi, Masahito; Suga, Sadao; Kawase, Takeshi; Nagasawa, Masakazu; Sadanaga, Humiko; Okamura, Miyuki; Kanai, Yoshihiro; Mihara, Ban

    1999-01-01

    Diffusion-weighted MRI has been demonstrated to be valuable in the assessment of cerebral stroke. Recent advance in MR systems of hardware with larger maximum gradient amplitude and faster imaging strategies, such as EPI, has made it possible to acquire whole brain diffusion-weighted imaging (DWI) in less that one minute. The purposes of this study are to evaluate clinical usefulness of DWI and to clarify pitfalls in the diagnosis of acute cerebral stroke. Seventeen patients with 18 ischemic lesions were studied. DWI were taken with 1.5 Tesla MRI (Magnetom Vision, Siemens, Germany) using EPI sequence. Fifteen lesions out of them (3 in cerebral cortex, 9 in basal ganglia/deep white matter and 3 in cerebellum) were studied serially at various times up to 147 days. Acute cerebral infarction was seen clearly as an area of hyperintensity with DWI and as hypointensity in apparent diffusion coefficient (ADC) maps which are indicative of decreased diffusion. DWI detected areas of hyperintense acute infarcts, as early as 2.5 hours after onset, which were not visualized on T 2 -weighted image (T2WI). The lesion of cerebral infarction became isointense in ADC maps at 14-28 days after onset, whereas with DWI it became isointense at about 2 months. Because ADC changed earlier than DWI, ADC maps were useful for differentiate acute from nonacute lesion in cases of recurrent stroke within a short period. In a patient with transient global amnesia for 7 hours, DWI did not show any lesion at 8 hours. In terms of cerebral hemorrhage, lesions were seen as area of hyperintensity in DWI at 3 days and were not distinguishable from that of infarct. Despite limitations in the diagnosis of transient ischemia and cerebral hemorrhage, DWI is a useful technique for early detection of cerebral infarction, especially within the first 6 hours after stroke onset. (author)

  8. Diagnosis of hemodynamic compromise in patients with chronic cerebral ischemia

    International Nuclear Information System (INIS)

    Kuroda, Satoshi; Sakuragi, Mitsugi; Motomiya, Mineo; Nakagawa, Tango; Mitsumori, Kenji; Tsuru, Mitsuo; Takigawa, Shugo; Kamiyama, Hiroyasu; Abe, Hiroshi.

    1990-01-01

    To evaluate the efficacy of tests for selecting patients with hemodynamic compromise, measurement of cerebral blood volume (CBV) with 99m Tc-RBC single photon emission computed tomography (SPECT) was performed in thirteen patients with occlusive cerebrovascular disease, and was compared with results obtained by 133 Xe SPECT and acetazolamide (Diamox) test. All patients in our study suffered TIA, RIND, or minor completed stroke. Cerebral angiography demonstrated severe stenosis or occlusion in the ipsilateral internal carotid artery or middle cerebral artery, although plain CT scan or MRI revealed no or, if any, only localized infarcted lesions. Regional cerebral blood volume (rCBV) was measured with 99m Tc-RBC SPECT and regional cerebral blood flow (rCBF) was measured with 133 Xe SPECT before and after intravenous injection of 10 - 12 mg/kg acetazolamide (Diamox). Our results suggest that the ipsilateral rCBV/rCBF (mean transit time) is a more sensitive index of the cerebral perfusion reserve than the use of only rCBV or rCBF of the ipsilateral hemisphere. Also, the ipsilateral rCBV/rCBF is significantly correlated (r= -0.72) with the Diamox reactivity of rCBF, which is considered to represent the cerebral vasodilatory capacity in patients with chronic cerebral ischemia. Postoperative SPECT study revealed remarkable improvement of ipsilateral rCBV/rCBF and Diamox reactivity in four patients who underwent EC/IC bypass surgery to improve the hemodynamic compromise. In conclusion, our results suggest that the measurement of rCBV/rCBF with 133 Xe SPECT and 99m Tc-RBC SPECT is useful for detecting the hemodynamic compromise in patients with occlusive cerebrovascular disease. (author)

  9. Normal diffusion-weighted imaging in cerebral air embolism complicating angiography

    Energy Technology Data Exchange (ETDEWEB)

    Sayama, T.; Inamura, T.; Fukui, M. [Dept. of Neurosurgery, Kyushu University Hospital, Fukuoka (Japan); Mitani, M.; Yagi, H. [Dept. of Neurosurgery, Yagi Hospital, Fukuoka (Japan)

    2000-03-01

    We report a case of cerebral air embolism resulting from accidental air infection during cerebral angiography. A 60-year-old man was accidentally injected with air via the left subclavian artery. Angiography demonstrated air within the basilar artery. The patient showed signs of posterior circulation ischaemia (confusion, blindness, gaze palsy and hemiparesis). However, MRI, including diffusion-weighted imaging, showed no abnormality 4 h later. The patient was treated with hyperbaric oxygen within 5 h of the embolism. All symptoms and signs resolved completely within a week. (orig.)

  10. Anti-cyclonic circulation driven by the estuarine circulation in a gulf type ROFI

    Science.gov (United States)

    Fujiwara, T.; Sanford, L. P.; Nakatsuji, K.; Sugiyama, Y.

    1997-08-01

    Baroclinic residual circulation processes are examined in gulf type Regions Of Freshwater Influence (ROFIs), which have large rivers discharging into a rounded head wider than the Rossby internal deformation radius. Theoretical and observational investigations concentrate on Ise Bay, Japan, with supporting data from Osaka Bay and Tokyo Bay. Simplified analytical solutions are derived to describe the primary features of the circulation. Three dimensional residual current data collected using moored current meters and shipboard acoustic doppler current profilers (ADCPs), satellite imagery and density structure data observed using STDs, are presented for comparison to the theoretical predictions. There are three key points to understanding the resulting circulation in gulf type ROFIs. First, there are likely to be three distinct water masses: the river plume, a brackish upper layer, and a higher salinity lower layer. Second, baroclinic processes in gulf type ROFIs are influenced by the Earth's rotation at first order. Residual currents are quasi-geostrophic and potential vorticity is approximately conserved. Third, the combined effects of a classical longitudinal estuarine circulation and the Earth's rotation are both necessary to produce the resulting circulation. Anti-cyclonic vorticity is generated in the upper layer by the horizontal divergence associated with upward entrainment, which is part of the estuarine circulation. The interaction between anti-cyclonic vorticity and horizontal divergence results in two regions of qualitatively different circulation, with gyre-like circulation near the bay head and uniformly seaward anti-cyclonicly sheared flow further towards the mouth. The stagnation point separating the two regions is closer to (further away from) the bay head for stronger (weaker) horizontal divergence, respectively. The vorticity and spin-up time of this circulation are-(ƒ-ω 1)/2 and h/2w 0, respectively, where ƒ is the Coriolis parameter, ω 1 is

  11. Unchanged cerebral blood flow and oxidative metabolism after acclimatization to high altitude

    DEFF Research Database (Denmark)

    Møller, Kirsten; Paulson, Olaf B; Hornbein, Thomas F.

    2002-01-01

    The authors investigated the effect of acclimatization to high altitude on cerebral blood flow and oxidative metabolism at rest and during exercise. Nine healthy, native sea-level residents were studied 3 weeks after arrival at Chacaltaya, Bolivia (5,260 m) and after reacclimatization to sea level....... At high altitude at rest, arterial carbon dioxide tension, oxygen saturation, and oxygen tension were significantly reduced, and arterial oxygen content was increased because of an increase in hemoglobin concentration. Global cerebral blood flow was similar in the four conditions. Cerebral oxygen delivery...... and cerebral metabolic rates of oxygen and glucose also remained unchanged, whereas cerebral metabolic rates of lactate increased slightly but nonsignificantly at high altitude during exercise compared with high altitude at rest. Reaction time was unchanged. The data indicate that cerebral blood flow...

  12. Cerebral sino-venous thrombosis

    International Nuclear Information System (INIS)

    Sayama, Ichiro; Kobayashi, Tsunesaburo; Nakajima, Kenji

    1982-01-01

    Three cases of cerebral sino-venous thrombosis were reported. Repeated CT findings were studied and discussed on account of the treatments for those pathologic conditions. Those of studied cases are; a 22-year-old postpartum woman, a 42-year-old woman with irregular vaginal bleeding, and a 26-year-old man with severe reactive emesis after drinking alcohol. They were treated conservatively. Case 1 died in its acute stage. In the remaining ones, each had an uneventful recovery. CT scan findings of them manifested their exact clinical conditions. These findings were devided into two categories, one was direct signs expressed sino-venous occlusion, the other was indirect signs which appeared as a result of these occlusion. Direct signs cannot always get in every cases with sino-venous occlusion, but as for indirect signs, we can get various changes corresponding to the time taken CT photoes, and they are useful to decide appropriate treatments at that time. Considering suitable treatments for this disease, it is necessary to select most suitable ones according to their pathologic conditions, which may be precisely drawn with CT scans. (J.P.N.)

  13. Clinical implication and prognosis of normal baseline cerebral blood flow with impaired vascular reserve in patients with major cerebral artery occlusive disease

    International Nuclear Information System (INIS)

    Isozaki, Makoto; Arai, Yoshikazu; Kubota, Toshihiko; Kikuta, Ken-ichiro; Kudo, Takashi; Kiyono, Yasushi; Kobayashi, Masato; Okazawa, Hidehiko

    2010-01-01

    To investigate the prognosis of patients with cerebrovascular steno-occlusive disease who have preserved baseline cerebral blood flow (CBF) and reduced cerebral vasoreactivity (CVR), they were followed up after scans of positron emission tomography (PET). Fifty-seven patients with symptomatic unilateral major cerebral arterial occlusion or severe stenosis underwent O-15 gas and water PET scans to measure cerebral blood volume, metabolic rate of oxygen, oxygen extraction fraction (OEF), and CBF at the baseline and after acetazolamide administration. Thirty of them (mean age 60±10 years) had normal ipsilateral CBF, and were followed prospectively at least 30 months from the last ischemic event. They were medically treated for cerebral circulation and underlying diseases during follow-up periods. The primary endpoint was determined as stroke recurrence during the follow-up. Thirty patients were divided into two groups of reduced CVR (N=16, 63±8 years) and normal CVR (N=14, 56±10 years) on the basis of CVR values from healthy volunteers. None of them showed significant laterality in baseline CBF and OEF between the hemispheres although patients with reduced CVR showed a tendency of ipsilateral increases in OEF and CBV. Patients were followed up for 50.5±19.0 and 48.1±12.4 months in the reduced and normal CVR groups, respectively. Although one patient with reduced CVR died of heart disease, there was no incidence of ischemic events during follow-up periods for either group. In the present prospective study, patients with sufficient baseline CBF showed good prognosis and no difference in recurrent stroke risks even though they had poor CVR in the affected hemisphere, indicating that these patients can be treated by medication for cerebral circulation and baseline diseases if they have high risk factors for neurosurgical treatment. (author)

  14. Cerebral blood flow in migraine and cortical spreading depression

    Energy Technology Data Exchange (ETDEWEB)

    Lauritzen, M.

    1987-01-01

    In a series of migraine patients, carotid arteriography was carried out as part of the clinical evalution. Nine patients developed a migrainous attack with focal neurological symptoms and headache after the angiography and during the subsequent, ongoing regional cerebral blood flow rCBF study. rCBF was measured by bolus injection of Xenon/sup 133/ into the internal carotid artery and a gamma camera with 254 collimated scintillation detectors covering the lateral aspect of the hemisphere. This technique depicts rCBF mainly at the level of the superficial cortex, with no depth resolution. The resolution is 1 cm/sup 2/ providing detailed spatial information of the cortical blood flow. Other methods for measuring local blood flow in animal and man employ a radioactive, freely diffusible tracer, in combination with an autoradiographic technique for the assessment of the tissue concentration, the so-called autoradiographic methods. In the series of patients with spontaneous migraine, rCBF was estimated using an in-vivo application of the autoradiographic principle. Xenon/sup 133/ was administered by inhalation and the time course of the arterial concentration curve was assessed by a scintillation detector over the upper right lung, since the arterial curve has been found to follow the shape of the lung curve. The rCBF was studied accompanying cortical spreading depression in rat experiments to evaluate wheter this phenomenon could explain the blood flow changes in migraine. (/sup 14/C) iodoantipyrine was given as an intravenous bolus injection and the brain content of indicator was determined by tissue sample or autoradiography after 10 or 20 seconds of isotope circulation. The conditions of the autoradiographic methods are that the flow remains constant within the period of measuring, and that the region under study is homogenous with regard to flow and lambda. (EG).

  15. A postural `stressed` cerebral HMPAO case study

    Energy Technology Data Exchange (ETDEWEB)

    Williams, R.C.; Jost, G.M.; Bolitho, L.; Grantham, M. [Wangaratta District Hospital, VIC (Australia)

    1998-03-01

    Full text: This case study represents an example of the utility of postural hypoperfusion stressed HMPAO SPECT. An elderly woman of 78 with a long history of giddiness was referred to our laboratory for examination of possible cerebral ischaemia. She had recurrent dizzy episodes, sometimes posture related, over the past few years and had suffered several falls. Cerebral DSA revealed minimal disease. CT scans were reported as normal. Carotid duplex Doppler studies revealed bilateral plaque disease in the carotid bulbs extending to the origins of the ICAs which were not significant stenoses. Postural symptoms were induced by standing the patient up rapidly and HMPAO was administered at the same time. A SPECT scan of the brain was performed. Quantitative analysis showed a left to right decrease of 10.8% in the temporo-occipital area, 5.6% in the temporo-parietal area and 2.5% in the cerebellar and parietal areas. Images revealed moderately reduced tracer concentration in the left half of the cerebellum and the left occipital region extending as far forward as the temporo-parietal region A repeat HMPAO SPECT scan without stress was normal. This would appear to indicate reversible ischaemia in the left posterior region, and is consistent with the reported symptoms. This case illustrates the usefulness of HMPAO in the diagnosis of reversible cerebral ischaemia.

  16. A postural 'stressed' cerebral HMPAO case study

    International Nuclear Information System (INIS)

    Williams, R.C.; Jost, G.M.; Bolitho, L.; Grantham, M.

    1998-01-01

    Full text: This case study represents an example of the utility of postural hypoperfusion stressed HMPAO SPECT. An elderly woman of 78 with a long history of giddiness was referred to our laboratory for examination of possible cerebral ischaemia. She had recurrent dizzy episodes, sometimes posture related, over the past few years and had suffered several falls. Cerebral DSA revealed minimal disease. CT scans were reported as normal. Carotid duplex Doppler studies revealed bilateral plaque disease in the carotid bulbs extending to the origins of the ICAs which were not significant stenoses. Postural symptoms were induced by standing the patient up rapidly and HMPAO was administered at the same time. A SPECT scan of the brain was performed. Quantitative analysis showed a left to right decrease of 10.8% in the temporo-occipital area, 5.6% in the temporo-parietal area and 2.5% in the cerebellar and parietal areas. Images revealed moderately reduced tracer concentration in the left half of the cerebellum and the left occipital region extending as far forward as the temporo-parietal region A repeat HMPAO SPECT scan without stress was normal. This would appear to indicate reversible ischaemia in the left posterior region, and is consistent with the reported symptoms. This case illustrates the usefulness of HMPAO in the diagnosis of reversible cerebral ischaemia

  17. Traumatic Anterior Cerebral Artery Pseudoaneurysmal Epistaxis.

    Science.gov (United States)

    Liu, Qing Lin; Xue, Hao; Qi, Chang Jing; Zhao, Peng; Wang, Dong Hai; Li, Gang

    2017-04-01

    Pseudoaneurysmal epistaxis is a rare but emergent condition. We report a case of traumatic anterior cerebral artery pseudoaneurysmal epistaxis and review the published literature. A 49-year-old man sustained severe head trauma. He was diagnosed with multiple skull bone fractures, left subdural hematoma, subarachnoid hemorrhage, pneumocephalus, and right frontal hematoma. Subdural hematoma evacuation was done at a local hospital. In the following months, he experienced repeated epistaxis that required nasal packing to stop the bleeding. Digital subtraction angiography showed an anterior cerebral artery pseudoaneurysm protruding into the posterior ethmoid sinus. Embolization of the aneurysm was performed with microcoils, and the parent artery was occluded by thrombosis. The patient presented 1 month later with another epistaxis episode. Digital subtraction angiography showed recanalization of the parent artery and recurrence of the aneurysm. The parent artery was occluded for the second time with coils and Onyx embolic agent. Pseudoaneurysmal epistaxis is rare, and this is the first report of an anterior cerebral artery pseudoaneurysm that manifested with epistaxis. Endovascular intervention has become the first choice of treatment for this disease. The high recurrence rate is the main disadvantage of endovascular intervention. Aneurysm trapping with bypass surgery is another treatment option. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Cerebral Laterality and Verbal Processes

    Science.gov (United States)

    Sherman, Jay L.; And Others

    1976-01-01

    Research suggests that we process information by way of two distinct and functionally separate coding systems. Their location, somewhat dependent on cerebral laterality, varies in right- and left-handed persons. Tests this dual coding model. (Editor/RK)

  19. Hydrocephalus in cerebral venous thrombosis

    NARCIS (Netherlands)

    Zuurbier, Susanna M.; van den Berg, René; Troost, Dirk; Majoie, Charles B.; Stam, Jan; Coutinho, Jonathan M.

    2015-01-01

    Increased intracranial pressure is common in cerebral venous thrombosis (CVT), but hydrocephalus is rarely reported in these patients. We examined the frequency, pathophysiology and associated clinical manifestations of hydrocephalus in patients with CVT admitted to our hospital between 2000 and

  20. Cerebral infarcts resulting from trauma

    International Nuclear Information System (INIS)

    Busch, G.

    1985-01-01

    Vascular occlusions due to cerebral trauma have always been regarded as great rarities. However, we have found hypo-dense foci of vascular distribution in 3.5% of 3500 CT examinations for trauma during the late phase. Lesions in the vascular territory of the posterior cerebral artery are usually the result of supratentorial pressure rise from epidural and subdural haematomas, leading to compression of the vessels against the edge of the tentorium. Typical infacts in the territory of the medial and anterior cerebral arteries were found only rarely by CT after cerebral trauma. Infarcts at the watersheds between the three vascular territories were found with surprising frequency and small infarcts were found in the basal ganglia. It is assumed that these were due to ischaemic or hypoxic events due to cardiac or pulmonary complications during the initial phase. (orig.) [de

  1. Cerebral Cavernous Malformation and Hemorrhage

    Science.gov (United States)

    ... Text Size: SMALL • LARGE Cerebral Cavernous Angioma and Hemorrhage By Jack Hoch; Reviewed by Dr. Issam Awad ... for years, the mechanism by which these lesions hemorrhage remains poorly understood. Hemorrhage Types Since cavernous angiomas ...

  2. MRI of cerebral alveolar echinococcosis

    International Nuclear Information System (INIS)

    Tunaci, M.; Tunaci, A.; Engin, G.; Oezkorkmaz, B.; Ahishali, B.; Rozanes, I.

    1999-01-01

    Cerebral alveolar echinococcosis is rare. We report a case with multiple intracranial masses which show cauliflower-like contrast enhancement pattern on MRI. The lesions originated from hepatic involvement with invasion of the inferior vena cava. (orig.)

  3. Learn More About Cerebral Palsy

    Centers for Disease Control (CDC) Podcasts

    2008-03-30

    This podcast describes the causes, preventions, types, and signs and symptoms of cerebral palsy.  Created: 3/30/2008 by National Center on Birth Defects and Developmental Disabilities.   Date Released: 3/21/2008.

  4. Regional cerebral perfusion in cardiovascular reflex syncope

    International Nuclear Information System (INIS)

    Toeyry, J.P.; Kuikka, J.T.; Laensimies, E.A.

    1997-01-01

    Little is known about the regional cerebral perfusion in subjects with presyncope or syncope, and the impact that autonomic nervous dysfunction has on it. Seven subjects with cardiovascular vasodepressor reflex syncope were studied. A baseline test was performed with the patients standing in the 70 upright position, while the passive head-up tilt table test with and without isoprenaline infusion was employed for provocation. Regional cerebral perfusion was assessed by means of single-photon emission tomography with technetium-99m labelled V-oxo-1,2-N,N 1 -ethylenedylbis-l-cysteine diethylester (baseline, and during blood pressure decline in the provocation test) and the autonomic nervous function by means of spectral analysis of heart rate variability (baseline, and before blood pressure decline in the provocation test). Every subject showed an abrupt decline in blood pressure in the provocation test (five with presyncope and two with syncope). The systolic and diastolic blood pressures decreased significantly (P<0.001) between the baseline and the provocation study time points (radiopharmaceutical injection and lowest systolic blood pressure). Mean cerebral perfusion as average count densities decreased upon provocation as compared with baseline (190±63 vs 307±90 counts/voxel, respectively, P=0.013). Hypoperfusion was most pronounced in the frontal lobe. These results suggest that cerebral perfusion decreases markedly during presyncope or syncope with systemic blood pressure decline in subjects with cardiovascular vasodepressor syncope. Furthermore, the autonomic nervous function remains unchanged before the systemic blood pressure decline. (orig.). With 3 figs., 2 tabs

  5. Parálisis cerebral :

    OpenAIRE

    Cabrero Izquierdo, María del Carmen

    2012-01-01

    Se aborda el tema de la parálisis cerebral definiendo qué es, clasificando los tipos de parálisis dependiendo de la afectación y las características principales. Se explican algunos de sus tratamientos, se dan sistemas alternativos y/o aumentativos de comunicación para un alumno con PC (parálisis cerebral).

  6. Cerebral candidiasis. Computed tomography appearance

    International Nuclear Information System (INIS)

    Chaabane, M.; Ladeb, M.F.; Bouhaouala, M.H.; Ben Hammouda, M.; Ataalah, R.; Gannouni, A.; Krifa, H.

    1989-01-01

    A three year old child who had been suffering from oral candidiasis since the age of 1 year presented with osteitis of the clavicle, 2 cerebral frontal abscesses and an occipital abscess which extended across the calvaria and was associated with osteolysis. Histological and microbiological studies following surgery confirmed the diagnosis of candidiasis in this girl who was found to have IgA immunodefinciency. The authors report the computed tomographic appearance of the cerebral lesions and review the literature. (orig.)

  7. Cerebral candidiasis. Computed tomography appearance

    Energy Technology Data Exchange (ETDEWEB)

    Chaabane, M.; Ladeb, M.F.; Bouhaouala, M.H.; Ben Hammouda, M.; Ataalah, R.; Gannouni, A.; Krifa, H.

    1989-07-01

    A three year old child who had been suffering from oral candidiasis since the age of 1 year presented with osteitis of the clavicle, 2 cerebral frontal abscesses and an occipital abscess which extended across the calvaria and was associated with osteolysis. Histological and microbiological studies following surgery confirmed the diagnosis of candidiasis in this girl who was found to have IgA immunodefinciency. The authors report the computed tomographic appearance of the cerebral lesions and review the literature. (orig.).

  8. The stability of the thermohaline circulation in a coupled ocean-atmosphere general circulation model

    Energy Technology Data Exchange (ETDEWEB)

    Schiller, A. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Mikolajewicz, U. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Voss, R. [Deutsches Klimarechenzentrum (DKRZ), Hamburg (Germany)

    1996-02-01

    The stability of the Atlantic thermohaline circulation against meltwater input is investigated in a coupled ocean-atmosphere general circulation model. The meltwater input to the Labrador Sea is increased linearly for 250 years to a maximum input of 0.625 Sv and then reduced again to 0 (both instantaneously and slowly decreasing over 250 years). The resulting freshening forces a shutdown of the formation of North Atlantic deepwater and a subsequent reversal of the thermohaline circulation of the Atlantic, filling the deep Atlantic with Antarctic bottom water. The change in the overturning pattern causes a drastic reduction of the Atlantic northward heat transport, resulting in a strong cooling with maximum amplitude over the northern North Atlantic and a southward shift of the sea-ice margin in the Atlantic. Due to the increased meridional temperature gradient, the Atlantic intertropical convergence zone is displaced southward and the westerlies in the northern hemisphere gain strength. We identify four main feedbacks affecting the stability of the thermohaline circulation: the change in the overturning circulation of the Atlantic leads to longer residence times of the surface waters in high northern latitudes, which allows them to accumulate more precipitation and runoff from the continents, which results in an increased stability in the North Atlantic.

  9. [Assessment of maternal cerebral blood flow in patients with preeclampsia].

    Science.gov (United States)

    Mandić, Vesna; Miković, Zeljko; Dukić, Milan; Vasiljević, Mladenko; Filimonović, Dejan; Bogavac, Mirjana

    2005-01-01

    Systemic vasoconstriction in preeclamptic patients increases vascular resistance, and is manifested by increased arterial blood flow velocity. The aim of the study is to evaluate if there is a change of Doppler indices in maternal medial cerbral artery (MCA) in severe preeclampsia due to: 1) severity of clinical symptoms, 2) the begining of eclamptic attack and 3) the application of anticonvulsive therapy. A prospective clinical study included 92 pregnant women, gestational age 28-36 weeks. They were divided into three groups: normotensive (n=30), mild preeclampsia (n=33), and severe preeclampsia (n=29). We investigated maternal cerebral circulation by assessing the MCA. We registrated: pulsatility index (Pi), resistance index (Ri), systolic/diastolic ratio (S/D), and the maximum systolic, end diastolic and medium velocity. Patients with severe preeclampsia were divided into two subgroups. subgroup 1 included patients without symptoms of threatening eclampsia (n=18; 62.06%); while subgroup 2 included those with symptoms of preeclampsia (n=11; 37.94%). All patients with severe preeclampsia were treated with magnesium sulfate (MgSO4), and cerebral blood flow was measured before and after the treatment. Statistical analysis was done by oneway ANOVA, Student t-test and t-paired sample test. The difference was considered to be significant if ppreclampsia we found increased velocity values, Pi and Ri, especially in patients with signs of threatened eclampsia, suggesting that blood vessels changes are most prominent in severe preeclampsia. Cerebral blood flow meassurements can be used as a clinical test for the prediction of eclampsia. Magnesium-sulfate (MgSO4) has a signifficant role in prophylaxis and treatment of eclampsia, and, therefore, positive influence on reduction of cerebral ishemic lesions can be expected. We can conclude that changes of the cerebral blood flow can be evaluated by evaluating blood flow velocities in the medial cerebral artery. Velocities tend

  10. First circulating beam in the AA

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    On 3 July 1980, two years after project authorization, beam circulated for the first time in the AA. It was a 3.5 GeV/c proton test beam. We see an expecting crowd, minutes before the happy event. The persons are to numerous to name them all. Heribert Koziol, apparently asleep, is answering the call from an impatient director. See also 8007094.

  11. Observations of the summer Red Sea circulation

    Science.gov (United States)

    Sofianos, Sarantis S.; Johns, William E.

    2007-06-01

    Aiming at exploring and understanding the summer circulation in the Red Sea, a cruise was conducted in the basin during the summer of 2001 involving hydrographic, meteorological, and direct current observations. The most prominent feature, characteristic of the summer circulation and exchange with the Indian Ocean, is a temperature, salinity, and oxygen minimum located around a depth of 75 m at the southern end of the basin, associated with Gulf of Aden Intermediate Water inflowing from the Gulf of Aden during the summer season as an intruding subsurface layer. Stirring and mixing with ambient waters lead to marked increases in temperature (from 16.5 to almost 33°C) and salinity (from 35.7 to more than 38 psu) in this layer by the time it reaches midbasin. The observed circulation presents a very vigorous pattern with strong variability and intense features that extend the width of the basin. A permanent cyclone, detected in the northern Red Sea, verifies previous observations and modeling studies, while in the central sector of the basin a series of very strong anticyclones were observed with maximum velocities exceeding 1 m/s. The three-layer flow pattern, representative of the summer exchange between the Red Sea and the Gulf of Aden, is observed in the strait of Bab el Mandeb. In the southern part of the basin the layer flow is characterized by strong banking of the inflows and outflows against the coasts. Both surface and intermediate water masses involved in the summer Red Sea circulation present prominent spatial variability in their characteristics, indicating that the eddy field and mixing processes play an important role in the summer Red Sea circulation.

  12. Seasonal overturning circulation in the Red Sea: 2. Winter circulation

    Science.gov (United States)

    Yao, Fengchao; Hoteit, Ibrahim; Pratt, Larry J.; Bower, Amy S.; Köhl, Armin; Gopalakrishnan, Ganesh; Rivas, David

    2014-04-01

    The shallow winter overturning circulation in the Red Sea is studied using a 50 year high-resolution MITgcm (MIT general circulation model) simulation with realistic atmospheric forcing. The overturning circulation for a typical year, represented by 1980, and the climatological mean are analyzed using model output to delineate the three-dimensional structure and to investigate the underlying dynamical mechanisms. The horizontal model circulation in the winter of 1980 is dominated by energetic eddies. The climatological model mean results suggest that the surface inflow intensifies in a western boundary current in the southern Red Sea that switches to an eastern boundary current north of 24°N. The overturning is accomplished through a cyclonic recirculation and a cross-basin overturning circulation in the northern Red Sea, with major sinking occurring along a narrow band of width about 20 km along the eastern boundary and weaker upwelling along the western boundary. The northward pressure gradient force, strong vertical mixing, and horizontal mixing near the boundary are the essential dynamical components in the model's winter overturning circulation. The simulated water exchange is not hydraulically controlled in the Strait of Bab el Mandeb; instead, the exchange is limited by bottom and lateral boundary friction and, to a lesser extent, by interfacial friction due to the vertical viscosity at the interface between the inflow and the outflow.

  13. Impact of short-term treatment with telmisartan on cerebral arterial remodeling in SHR.

    Directory of Open Access Journals (Sweden)

    Sébastien Foulquier

    Full Text Available Chronic hypertension decreases internal diameter of cerebral arteries and arterioles. We recently showed that short-term treatment with the angiotensin II receptor blocker telmisartan restored baseline internal diameter of small cerebral arterioles in spontaneously hypertensive rats (SHR, via reversal of structural remodeling and inhibition of the angiotensin II vasoconstrictor response. As larger arteries also participate in the regulation of cerebral circulation, we evaluated whether similar short-term treatment affects middle cerebral arteries of SHR.Baseline internal diameters of pressurised middle cerebral arteries from SHR and their respective controls, Wistar Kyoto rats (WKY and responses to angiotensin II were studied in a small vessel arteriograph. Pressure myogenic curves and passive internal diameters were measured following EDTA deactivation, and elastic modulus from stress-strain relationships.Active baseline internal diameter was 23% lower in SHR compared to WKY, passive internal diameter (EDTA 28% lower and elastic modulus unchanged. Pressure myogenic curves were shifted to higher pressure values in SHR. Telmisartan lowered blood pressure but had no effect on baseline internal diameter nor on structural remodeling (passive internal diameter and elastic modulus remained unchanged compared to SHR. Telmisartan shifted the pressure myogenic curve to lower pressure values than SHR.In the middle cerebral arteries of SHR, short-term treatment with telmisartan had no effect on structural remodeling and did not restore baseline internal diameter, but allowed myogenic tone to adapt towards lower pressure values.

  14. Value of cerebral blood flow rate and regional oxygen consumption studies in cerebral ischaemia

    Energy Technology Data Exchange (ETDEWEB)

    Clanet, M

    1987-06-18

    Studies of experimentally-induced ischaemia have shown that the intensity of neuronal suffering is related to the fall in perfusion rate. Below a certain level, called functional threshold, cerebral function is reversibly altered, whereas at a lower level (tissue necrosis threshold) the damage inflicted on neurons is irreversible. Between these two thresholds lies a ''penumbra zone''. This concept of thresholds must be mitigated by 2 parameters: duration of ischaemia and selective vulnerability of the various structures affected. Variations in blood flow rate only indirectly affect the state of tissues. Techniques developed from positron emission tomography make it possible to evaluate the metabolic activity of brain tissue in vivo: oxygen consumption (CMRO/sub 2/), oxygen extraction (EO/sub 2/) and glucose consumption (CMRG) which are thus correlated to cerebral blood flow and cerebral blood volume, sometimes also to tissue pH. Normal relations between blood flow rate and metabolism may be altered. Misery perfusion reflects a fall in cerebral blood flow with an increase in EO/sub 2/ and often a decrease in CMRO/sub 2/, whereas luxury perfusion reflects an increase in cerebral blood flow rate with reduction of CMRO/sub 2/, EO/sub 2/ and CMRG. The type of alteration encountered in human ischaemia varies according to the nature of the accident: studies of transient accidents emphasize the different haemodynamic aspects of occlusion of the wider arteries. The metabolic and haemodynamic profiles of established ischaemic accidents vary according to their type and to the time of the study, reflecting the complexity of the physiopathological mechanisms involved; they are frequently associated with metabolic repercussions at a distance from the ischaemic focus, which supports the concept of diaschisis.

  15. Value of cerebral blood flow rate and regional oxygen consumption studies in cerebral ischaemia

    International Nuclear Information System (INIS)

    Clanet, M.

    1987-01-01

    Studies of experimentally-induced ischaemia have shown that the intensity of neuronal suffering is related to the fall in perfusion rate. Below a certain level, called functional threshold, cerebral function is reversibly altered, whereas at a lower level (tissue necrosis threshold) the damage inflicted on neurons is irreversible. Between these two thresholds lies a ''penumbra zone''. This concept of thresholds must be mitigated by 2 parameters: duration of ischaemia and selective vulnerability of the various structures affected. Variations in blood flow rate only indirectly affect the state of tissues. Techniques developed from positron emission tomography make it possible to evaluate the metabolic activity of brain tissue in vivo: oxygen consumption (CMRO 2 ), oxygen extraction (EO 2 ) and glucose consumption (CMRG) which are thus correlated to cerebral blood flow and cerebral blood volume, sometimes also to tissue pH. Normal relations between blood flow rate and metabolism may be altered. Misery perfusion reflects a fall in cerebral blood flow with an increase in EO 2 and often a decrease in CMRO 2 , whereas luxury perfusion reflects an increase in cerebral blood flow rate with reduction of CMRO 2 , EO 2 and CMRG. The type of alteration encountered in human ischaemia varies according to the nature of the accident: studies of transient accidents emphasize the different haemodynamic aspects of occlusion of the wider arteries. The metabolic and haemodynamic profiles of established ischaemic accidents vary according to their type and to the time of the study, reflecting the complexity of the physiopathological mechanisms involved; they are frequently associated with metabolic repercussions at a distance from the ischaemic focus, which supports the concept of diaschisis [fr

  16. Cerebral CT of ischaemic lesions

    Energy Technology Data Exchange (ETDEWEB)

    Aulich, A

    1981-11-25

    The diagnosis of stroke must first be established by clinical examination. CT has proved useful for confirmation of the diagnosis and provides a global intracranial picture of morphological changes in cerebral vascular diseases. A hemorrhage can be recognized with certainty at the first CT examination as the cause of the stroke, but in the detection of a lesion due to ischemia an important role is played by the correct choice of the time of examination, and in some cases also of the check-up with contrast medium. The differential diagnosis between infarct in the acute stage and encephalitis or gliomas of low-grade malignity can be difficult. A decision can often only be made after a series of examinations. Postmalacial conditions are often difficult to differentiate from defects due to other causes, such as hemorrhage, head injury, postoperative states and after encephalitis. A knowledge of the anamnesis and the clinical findings is indispensable for CT evaluation. In assessing the prognosis before vascular surgery on the extracranial brain-supplying vessels the performance of a CT examination should be advised. A warning is given against the use of CT as a screening method.

  17. Cerebral venous sinus thrombosis in HIV-infected patients: report of 2 cases.

    Science.gov (United States)

    Mwita, Julius Chacha; Baliki, Kgomotso; Tema, Ludo

    2013-01-01

    Infection with the human immunodeficiency virus (HIV) is associated with increased risk of cerebrovascular disease; however Cerebral Venous Sinus Thrombosis (CVST) is rarely associated with HIV-related cerebrovascular events. We describe two cases of HIV-positive patients who, at the same time, presented to our hospital with deep cerebral venous thrombosis and stroke.

  18. Cerebral blood flow velocity changes during upright positioning in bed after acute stroke : An observational study

    NARCIS (Netherlands)

    Aries, Marcel J; Elting, Jan Willem; Stewart, Roy; De Keyser, Jacques; Kremer, Berry; Vroomen, Patrick

    2013-01-01

    Objectives: National guidelines recommend mobilisation in bed as early as possible after acute stroke. Little is known about the influence of upright positioning on real-time cerebral flow variables in patients with stroke. We aimed to assess whether cerebral blood flow velocity (CBFV) changes

  19. Proprioceptive evoked potentials in man: cerebral responses to changing weight loads on the hand

    DEFF Research Database (Denmark)

    Arnfred, S; He, Chen; Eder, D

    2000-01-01

    We studied cerebral evoked potentials on the scalp to the stimulation of the right hand from a change in weight of 400-480 g in ten subjects. Rise-time was 20g/10 ms, Inter Stimulus Interval 2s and stimulus duration was 100 ms. The cerebral activations were a double positive contralateral C3'/P70...

  20. Preterm birth and cerebral palsy. Predictive value of pregnancy complications, mode of delivery, and Apgar scores

    DEFF Research Database (Denmark)

    Topp, Monica Wedell; Langhoff-Roos, J; Uldall, P

    1997-01-01

    BACKGROUND: Preterm infants are at 8 times higher risk than term infants for pre- and perinatal brain damage, resulting in cerebral palsy. In this paper we have analysed the influence of prenatal and birth-related risk factors on cerebral palsy in preterm infants. METHODS: In a register-based stu...

  1. IGF-1 deficiency impairs cerebral myogenic autoregulation in hypertensive mice.

    Science.gov (United States)

    Toth, Peter; Tucsek, Zsuzsanna; Tarantini, Stefano; Sosnowska, Danuta; Gautam, Tripti; Mitschelen, Matthew; Koller, Akos; Sonntag, William E; Csiszar, Anna; Ungvari, Zoltan

    2014-12-01

    Aging impairs autoregulatory protection in the brain, exacerbating hypertension-induced cerebromicrovascular injury, neuroinflammation, and development of vascular cognitive impairment. Despite the importance of the age-related decline in circulating insulin-like growth factor-1 (IGF-1) levels in cerebrovascular aging, the effects of IGF-1 deficiency on functional adaptation of cerebral arteries to high blood pressure remain elusive. To determine whether IGF-1 deficiency impairs autoregulatory protection, hypertension was induced in control and IGF-1-deficient mice (Igf1(f/f)+TBG-iCre-AAV8) by chronic infusion of angiotensin-II. In hypertensive control mice, cerebral blood flow (CBF) autoregulation was extended to higher pressure values and the pressure-induced tone of middle cerebral arteries (MCAs) was increased. In hypertensive IGF-1-deficient mice, autoregulation was markedly disrupted, and MCAs did not show adaptive increases in myogenic tone. In control mice, the mechanism of adaptation to hypertension involved upregulation of TRPC channels in MCAs and this mechanism was impaired in hypertensive IGF-1-deficient mice. Likely downstream consequences of cerebrovascular autoregulatory dysfunction in hypertensive IGF-1-deficient mice included exacerbated disruption of the blood-brain barrier and neuroinflammation (microglia activation and upregulation of proinflammatory cytokines and chemokines), which were associated with impaired hippocampal cognitive function. Collectively, IGF-1 deficiency impairs autoregulatory protection in the brain of hypertensive mice, potentially exacerbating cerebromicrovascular injury and neuroinflammation mimicking the aging phenotype.

  2. Cerebral trypanosomiasis and AIDS

    Directory of Open Access Journals (Sweden)

    Antunes Apio Claudio Martins

    2002-01-01

    Full Text Available A 36 year-old black female, complaining of headache of one month's duration presented with nausea, vomiting, somnolence, short memory problems, loss of weight, and no fever history. Smoker, intravenous drugs abuser, promiscuous lifestyle. Physical examination: left homonimous hemianopsia, left hemiparesis, no papilledema, diffuse hyperreflexia, slowness of movements. Brain CT scan: tumor-like lesion in the splenium of the corpus calosum, measuring 3.5 x 1.4 cm, with heterogeneous enhancing pattern, sugesting a primary CNS tumor. Due to the possibility of CNS infection, a lumbar puncture disclosed an opening pressure of 380 mmH(20; 11 white cells (lymphocytes; glucose 18 mg/dl (serum glucose 73 mg/dl; proteins 139 mg/dl; presence of Trypanosoma parasites. Serum Elisa-HIV tests turned out to be positive. Treatment with benznidazole dramatically improved clinical and radiographic picture, but the patient died 6 weeks later because of respiratory failure. T. cruzi infection of the CNS is a rare disease, but we have an increasing number of cases in HIV immunecompromised patients. Diagnosis by direct observation of CSF is uncommon, and most of the cases are diagnosed by pathological examination. It is a highly lethal disease, even when properly diagnosed and treated. This article intends to include cerebral trypanosomiasis in the differential diagnosis of intracranial space-occupying lesions, especially in immunecompromised patients from endemic regions.

  3. Pseudotumoral delayed cerebral radionecrosis

    International Nuclear Information System (INIS)

    Ciaudo-Lacroix, C.; Lapresle, J.

    1985-01-01

    A 60 year-old woman with a scalp epithelioma underwent radiotherapy, the dose being 57 Gray. A first epileptic seizure occurred twenty months later. Neurological examination revealed signs of left hemisphere involvement. γEG, angiography, CT scans, demonstrated a pseudotumoral avascular process. On account of the localisation, the patient being right-handed, no surgical procedure was performed. In spite of corticotherapy and anticonvulsive treatment, seizures recurred and neurological signs slowly progressed. The patient died, 22 months after the first seizure, of an associated disseminated carcinoma with cachexia. Neuropathological examination showed a massive lesion presenting all the features of delayed radionecrosis in the left hemisphere: situated mainly in the white matter; numerous vascular abnormalities; wide-spread demyelination; disappearance of oligoglial cells. The Authors recall the clinical and anatomical aspects of this condition for which the only successful treatment is surgical removal when location and size of the lesion permit. Finally, the mechanisms which have been proposed to explain this delayed cerebral radionecrosis are discussed [fr

  4. Pseudotumoral delayed cerebral radionecrosis

    Energy Technology Data Exchange (ETDEWEB)

    Ciaudo-Lacroix, C; Lapresle, J [Centre Hospitalier de Bicetre, 94 - Le Kremlin-Bicetre (France)

    1985-01-01

    A 60 year-old woman with a scalp epithelioma underwent radiotherapy, the dose being 57 Gray. A first epileptic seizure occurred twenty months later. Neurological examination revealed signs of left hemisphere involvement. ..gamma..EG, angiography, CT scans, demonstrated a pseudotumoral avascular process. On account of the localisation, the patient being right-handed, no surgical procedure was performed. In spite of corticotherapy and anticonvulsive treatment, seizures recurred and neurological signs slowly progressed. The patient died, 22 months after the first seizure, of an associated disseminated carcinoma with cachexia. Neuropathological examination showed a massive lesion presenting all the features of delayed radionecrosis in the left hemisphere: situated mainly in the white matter; numerous vascular abnormalities; wide-spread demyelination; disappearance of oligoglial cells. The Authors recall the clinical and anatomical aspects of this condition for which the only successful treatment is surgical removal when location and size of the lesion permit. Finally, the mechanisms which have been proposed to explain this delayed cerebral radionecrosis are discussed.

  5. Gas-cooled reactor coolant circulator and blower technology

    International Nuclear Information System (INIS)

    1988-08-01

    In the previous 17 meetings held within the framework of the International Working Group on Gas-Cooled Reactors, a wide variety of topics and components have been addressed, but the San Diego meeting represented the first time that a group of specialists had been convened to discuss circulator and blower related technology. A total of 20 specialists from 6 countries attended the meeting in which 15 technical papers were presented in 5 sessions: circulator operating experience I and II (6 papers); circulator design considerations I and II (6 papers); bearing technology (3 papers). A separate abstract was prepared for each of these papers. Refs, figs and tabs

  6. The circulation of Amway's discourse: from control to social practice

    OpenAIRE

    Brunelli, Anna Flora

    2013-01-01

    In this paper, we intend to contribute to the debate about the circulation of the discourses. To do that, we analyze aspects regarding the circulation of Amway's discourse, a North-American network sales company that has been working in Brazil for a while. Precisely, we analyze the conditions of this circulation at the time it was more intensively, ie, in the 90s, when there were thousands of people in several parts of the country selling the company's products or consuming them. This study h...

  7. Natural-circulation-cooling characteristics during PWR accident simulations

    International Nuclear Information System (INIS)

    Adams, J.P.; McCreery, G.E.; Berta, V.T.

    1983-01-01

    A description of natural circulation cooling characteristics is presented. Data were obtained from several pressurized water reactor accident simulations in the Loss-of-Fluid Test (LOFT) pressurized water reactor (PWR). The reliability of natural circulation cooling, its cooling effectiveness, and the effect of changing system conditions are described. Quantitative comparison of flow rates and time constants with theory for both single- and two-phase fluid conditions were made. It is concluded that natural circulation cooling can be relied on in plant recovery procedures in the absence of forced convection whenever the steam generator heat sink is available

  8. Cerebral Aneurysm in the Evolution of Cardiac Myxoma: Clinical and Physiopathological Interpretations; El aneurisma cerebral en la evolucion del mixoma cardiaco: planteamientos clinicos y fisopatologicos

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, R.; Garcia, M. L. [Hospital General Universitario Morales Meseguer. Murcia (Spain)

    2003-07-01

    We present the case of a patient with stroke, cerebral aneurysms (small distal and large proximal) who had been treated for cardiac myxoma 18 years earlier. We compared the imaging findings (localization, size, density and associated cerebral lesions) with those of other publications. The data obtained from other works and those that we could derive from our patient suggest that the cerebral aneurysms are responsible for neurological symptoms observed some time after removal of the tumor. On the other hand, such aneurysms tend to grow larger and more proximal with increasing time after surgery. (Author) 15 refs.

  9. Producing superfluid circulation states using phase imprinting

    Science.gov (United States)

    Kumar, Avinash; Dubessy, Romain; Badr, Thomas; De Rossi, Camilla; de Goër de Herve, Mathieu; Longchambon, Laurent; Perrin, Hélène

    2018-04-01

    We propose a method to prepare states of given quantized circulation in annular Bose-Einstein condensates (BEC) confined in a ring trap using the method of phase imprinting without relying on a two-photon angular momentum transfer. The desired phase profile is imprinted on the atomic wave function using a short light pulse with a tailored intensity pattern generated with a spatial light modulator. We demonstrate the realization of "helicoidal" intensity profiles suitable for this purpose. Due to the diffraction limit, the theoretical steplike intensity profile is not achievable in practice. We investigate the effect of imprinting an intensity profile smoothed by a finite optical resolution onto the annular BEC with a numerical simulation of the time-dependent Gross-Pitaevskii equation. This allows us to optimize the intensity pattern for a given target circulation to compensate for the limited resolution.

  10. On-Chip Microwave Quantum Hall Circulator

    Directory of Open Access Journals (Sweden)

    A. C. Mahoney

    2017-01-01

    Full Text Available Circulators are nonreciprocal circuit elements that are integral to technologies including radar systems, microwave communication transceivers, and the readout of quantum information devices. Their nonreciprocity arises from the interference of microwaves over the centimeter scale of the signal wavelength, in the presence of bulky magnetic media that breaks time-reversal symmetry. Here, we realize a completely passive on-chip microwave circulator with size 1/1000th the wavelength by exploiting the chiral, “slow-light” response of a two-dimensional electron gas in the quantum Hall regime. For an integrated GaAs device with 330  μm diameter and about 1-GHz center frequency, a nonreciprocity of 25 dB is observed over a 50-MHz bandwidth. Furthermore, the nonreciprocity can be dynamically tuned by varying the voltage at the port, an aspect that may enable reconfigurable passive routing of microwave signals on chip.

  11. Cerebral ischemia produced by four-vessel occlusion in the rat: a quantitative evaluation of cerebral blood flow

    International Nuclear Information System (INIS)

    Furlow, T.W. Jr.

    1982-01-01

    Cerebral ischemia was produced in the rat by simultaneous occlusion of the vertebral and carotid arteries according to the method of Pulsinelli and Brierley (Stroke 10: 267, 1979). Local cerebral blood flow (CBF) was determined by polarographic and autoradiographic techniques. Hydrogen-clearance measurements showed that mean CBF fell in four monitored regions of the hemispheres to between 0.11 and 0.18 ml/g/min, being least in deep rostal gray, intermediate in superficial gray, and greatest in deep caudal gray. However, individual animals had local CBF in excess of 0.20 and even 0.30 ml/g/min, and no animal showed zero CBF. When animals were rendered hypotensive (MABP of 50 Torr) during vascular occlusion, mean CBF ranged between 0.03 and 0.10 ml/g/min in the same regional order. With hypotension, total arrest of flow occurred. Autoradiographic data confirmed the above findings and indicated adequate CBF to the lower brainstem. During vascular occlusion, sufficient CBF may be present ot sustain cerebral tissue as in animals with a well developed spinal circulation or an inadvertently patent vertebral artery

  12. Time Is Brain: The Stroke Theory of Relativity.

    Science.gov (United States)

    Gomez, Camilo R

    2018-04-25

    Since the introduction of the philosophical tenet "Time is Brain!," multiple lines of research have demonstrated that other factors contribute to the degree of ischemic injury at any one point in time, and it is now clear that the therapeutic window of acute ischemic stroke is more protracted than it was first suspected. To define a more realistic relationship between time and the ischemic process, we used computational modeling to assess how these 2 variables are affected by collateral circulatory competence. Starting from the premise that the expression "Time=Brain" is mathematically false, we reviewed the existing literature on the attributes of cerebral ischemia over time, with particular attention to relevant clinical parameters, and the effect of different variables, particularly collateral circulation, on the time-ischemia relationship. We used this information to construct a theoretical computational model and applied it to categorically different yet abnormal cerebral perfusion scenarios, allowing comparison of their behavior both overall (i.e., final infarct volume) and in real-time (i.e., ins