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Sample records for impaired cerebral autoregulation

  1. Autonomic dysfunction and impaired cerebral autoregulation in cirrhosis

    DEFF Research Database (Denmark)

    Frøkjaer, Vibe G; Strauss, Gitte I; Mehlsen, Jesper

    2006-01-01

    .0+/-2.0 bpm) compared to the controls (21.7+/-2.2 bpm, p=0.001, Tukey' test). Systolic blood pressure fell during head-up tilt only in patients with severe cirrhosis. Our results imply that cerebral autoregulation was impaired in the most severe cases of liver cirrhosis, and that those with impaired cerebral...

  2. Autonomic dysfunction and impaired cerebral autoregulation in cirrhosis

    DEFF Research Database (Denmark)

    Frøkjaer, Vibe G; Mehlsen, Jesper; Knudsen, Gitte M;

    2006-01-01

    by norepinephrine infusion (NE). The severity of liver disease was assessed using the Child-Pugh scale (class A, mild; class B, moderate; class C, severe liver dysfunction).NE increased blood pressure similarly in the controls (27 (24-32) mmHg) and patients with the most severe liver cirrhosis (Child-Pugh C, 31 (26.......0+/-2.0 bpm) compared to the controls (21.7+/-2.2 bpm, p=0.001, Tukey' test). Systolic blood pressure fell during head-up tilt only in patients with severe cirrhosis. Our results imply that cerebral autoregulation was impaired in the most severe cases of liver cirrhosis, and that those with impaired cerebral......Cerebral blood flow autoregulation is lost in patients with severe liver cirrhosis. The cause of this is unknown. We determined whether autonomic dysfunction was related to impaired cerebral autoregulation in patients with cirrhosis. Fourteen patients with liver cirrhosis and 11 healthy volunteers...

  3. Impaired Cerebral Autoregulation Using Near-Infrared Spectroscopy and Its Relation to Clinical Outcomes in Premature Infants

    NARCIS (Netherlands)

    Caicedo, Alexander; De Smet, Dominique; Vanderhaegen, Joke; Naulaers, Gunnar; Wolf, Martin; Lemmers, Petra; Van Bel, Frank; Ameye, Lieveke; Van Huffel, Sabine; LaManna, JC; Puchowicz, MA; Xu, K; Harrison, DK; Bruley, DF

    2011-01-01

    The concordance between the change in the Mean Arterial Blood Pressure (MABP) and the Cerebral Blood Flow (CBF) is studied using the Correlation, Coherence and Partial Coherence methods in order to detect Impaired Cerebral Autoregulation in Neonates. The presence of impaired autoregulation is assess

  4. Detection of Impaired Cerebral Autoregulation Using Selected Correlation Analysis: A Validation Study

    Science.gov (United States)

    Brawanski, Alexander

    2017-01-01

    Multimodal brain monitoring has been utilized to optimize treatment of patients with critical neurological diseases. However, the amount of data requires an integrative tool set to unmask pathological events in a timely fashion. Recently we have introduced a mathematical model allowing the simulation of pathophysiological conditions such as reduced intracranial compliance and impaired autoregulation. Utilizing a mathematical tool set called selected correlation analysis (sca), correlation patterns, which indicate impaired autoregulation, can be detected in patient data sets (scp). In this study we compared the results of the sca with the pressure reactivity index (PRx), an established marker for impaired autoregulation. Mean PRx values were significantly higher in time segments identified as scp compared to segments showing no selected correlations (nsc). The sca based approach predicted cerebral autoregulation failure with a sensitivity of 78.8% and a specificity of 62.6%. Autoregulation failure, as detected by the results of both analysis methods, was significantly correlated with poor outcome. Sca of brain monitoring data detects impaired autoregulation with high sensitivity and sufficient specificity. Since the sca approach allows the simultaneous detection of both major pathological conditions, disturbed autoregulation and reduced compliance, it may become a useful analysis tool for brain multimodal monitoring data. PMID:28255331

  5. Detection of Impaired Cerebral Autoregulation Using Selected Correlation Analysis: A Validation Study

    Directory of Open Access Journals (Sweden)

    Martin A. Proescholdt

    2017-01-01

    Full Text Available Multimodal brain monitoring has been utilized to optimize treatment of patients with critical neurological diseases. However, the amount of data requires an integrative tool set to unmask pathological events in a timely fashion. Recently we have introduced a mathematical model allowing the simulation of pathophysiological conditions such as reduced intracranial compliance and impaired autoregulation. Utilizing a mathematical tool set called selected correlation analysis (sca, correlation patterns, which indicate impaired autoregulation, can be detected in patient data sets (scp. In this study we compared the results of the sca with the pressure reactivity index (PRx, an established marker for impaired autoregulation. Mean PRx values were significantly higher in time segments identified as scp compared to segments showing no selected correlations (nsc. The sca based approach predicted cerebral autoregulation failure with a sensitivity of 78.8% and a specificity of 62.6%. Autoregulation failure, as detected by the results of both analysis methods, was significantly correlated with poor outcome. Sca of brain monitoring data detects impaired autoregulation with high sensitivity and sufficient specificity. Since the sca approach allows the simultaneous detection of both major pathological conditions, disturbed autoregulation and reduced compliance, it may become a useful analysis tool for brain multimodal monitoring data.

  6. Impaired Cerebral Autoregulation during Head Up Tilt in Patients with Severe Brain Injury

    DEFF Research Database (Denmark)

    Riberholt, Christian Gunge; Olesen, Niels Damkjær; Thing, Mira;

    2016-01-01

    acquired brain injury and a low level of consciousness. Fourteen patients with severe acquired brain injury and orthostatic intolerance and fifteen healthy volunteers were enrolled. Blood pressure was evaluated by pulse contour analysis, heart rate and RR-intervals were determined by electrocardiography...... mean velocity and estimated cerebral perfusion pressure. Patients with acquired brain injury presented an increase in mean flow index during head-up tilt indicating impaired autoregulation (P ....1 Hz spectral power in patients compared to healthy controls suggesting baroreflex dysfunction. In conclusion, patients with severe acquired brain injury and orthostatic intolerance during head-up tilt have impaired cerebral autoregulation more than one month after brain injury....

  7. Impaired Cerebral Autoregulation during Head Up Tilt in Patients with Severe Brain Injury.

    Directory of Open Access Journals (Sweden)

    Christian Gunge Riberholt

    Full Text Available Early mobilization is of importance for improving long-term outcome for patients after severe acquired brain injury. A limiting factor for early mobilization by head-up tilt is orthostatic intolerance. The purpose of the present study was to examine cerebral autoregulation in patients with severe acquired brain injury and a low level of consciousness. Fourteen patients with severe acquired brain injury and orthostatic intolerance and fifteen healthy volunteers were enrolled. Blood pressure was evaluated by pulse contour analysis, heart rate and RR-intervals were determined by electrocardiography, middle cerebral artery velocity was evaluated by transcranial Doppler, and near-infrared spectroscopy determined frontal lobe oxygenation in the supine position and during head-up tilt. Cerebral autoregulation was evaluated as the mean flow index calculated as the ratio between middle cerebral artery mean velocity and estimated cerebral perfusion pressure. Patients with acquired brain injury presented an increase in mean flow index during head-up tilt indicating impaired autoregulation (P < 0.001. Spectral analysis of heart rate variability in the frequency domain revealed lower magnitudes of ~0.1 Hz spectral power in patients compared to healthy controls suggesting baroreflex dysfunction. In conclusion, patients with severe acquired brain injury and orthostatic intolerance during head-up tilt have impaired cerebral autoregulation more than one month after brain injury.

  8. Cerebral Autoregulation in Normal Pregnancy and Preeclampsia

    NARCIS (Netherlands)

    van Veen, Teelkien R.; Panerai, Ronney B.; Haeri, Sina; Griffioen, Annemiek C.; Zeeman, Gerda; Belfort, Michael A.

    2013-01-01

    OBJECTIVE: To test the hypothesis that preeclampsia is associated with impaired dynamic cerebral autoregulation. METHODS: In a prospective cohort analysis, cerebral blood flow velocity of the middle cerebral artery (determined by transcranial Doppler), blood pressure (determined by noninvasive arter

  9. Impaired cerebral autoregulation during upright tilt in patients with severe brain injury

    DEFF Research Database (Denmark)

    Hansen, Christian Riberholt; Olesen, Niels; Thing, Mira

    Objectives: Upright tilt is an important tool for early mobilization of patients after severe acquired brain injury (ABI). Early mobilization is considered to be of importance for increasing awareness, in the prevention of contractures and pulmonary infections and to improve long-term outcome....... A challenge for early mobilization is orthostatic instability that is often observed during heap-up tilt, which could lead to decreased cerebral blood flow velocity (CBFV) and decreased long-term outcome. We examined cerebral blood flow autoregulation in patients with severe brain injury and impaired...

  10. Impaired cerebral autoregulation is associated with brain atrophy and worse functional status in chronic ischemic stroke.

    Directory of Open Access Journals (Sweden)

    Mikio C Aoi

    Full Text Available Dynamic cerebral autoregulation (dCA is impaired following stroke. However, the relationship between dCA, brain atrophy, and functional outcomes following stroke remains unclear. In this study, we aimed to determine whether impairment of dCA is associated with atrophy in specific regions or globally, thereby affecting daily functions in stroke patients.We performed a retrospective analysis of 33 subjects with chronic infarctions in the middle cerebral artery territory, and 109 age-matched non-stroke subjects. dCA was assessed via the phase relationship between arterial blood pressure and cerebral blood flow velocity. Brain tissue volumes were quantified from MRI. Functional status was assessed by gait speed, instrumental activities of daily living (IADL, modified Rankin Scale, and NIH Stroke Score.Compared to the non-stroke group, stroke subjects showed degraded dCA bilaterally, and showed gray matter atrophy in the frontal, parietal and temporal lobes ipsilateral to infarct. In stroke subjects, better dCA was associated with less temporal lobe gray matter atrophy on the infracted side ([Formula: see text] = 0.029, faster gait speed ([Formula: see text] = 0.018 and lower IADL score ([Formula: see text]0.002. Our results indicate that better dynamic cerebral perfusion regulation is associated with less atrophy and better long-term functional status in older adults with chronic ischemic infarctions.

  11. Impaired dynamic cerebral autoregulation at rest and during isometric exercise in type 2 diabetes patients.

    Science.gov (United States)

    Vianna, Lauro C; Deo, Shekhar H; Jensen, Areum K; Holwerda, Seth W; Zimmerman, Matthew C; Fadel, Paul J

    2015-04-01

    Type 2 diabetes mellitus patients (T2D) have elevated risk of stroke, suggesting that cerebrovascular function is impaired. Herein, we examined dynamic cerebral autoregulation (CA) at rest and during exercise in T2D patients and determined whether underlying systemic oxidative stress is associated with impairments in CA. Middle cerebral artery blood velocity and arterial blood pressure (BP) were measured at rest and during 2-min bouts of low- and high-intensity isometric handgrip performed at 20% and 40% maximum voluntary contraction, respectively, in seven normotensive and eight hypertensive T2D patients and eight healthy controls. Dynamic CA was estimated using the rate of regulation (RoR). Total reactive oxygen species (ROS) and superoxide levels were measured at rest. There were no differences in RoR at rest or during exercise between normotensive and hypertensive T2D patients. However, when compared with controls, T2D patients exhibited lower RoR at rest and during low-intensity handgrip indicating impaired dynamic CA. Moreover, the RoR was further reduced by 29 ± 4% during high-intensity handgrip in T2D patients (0.307 ± 0.012/s rest vs. 0.220 ± 0.014/s high intensity; P < 0.01), although well maintained in controls. T2D patients demonstrated greater baseline total ROS and superoxide compared with controls, both of which were negatively related to RoR during handgrip (e.g., total ROS: r = -0.71, P < 0.05; 40% maximum voluntary contraction). Collectively, these data demonstrate impaired dynamic CA at rest and during isometric handgrip in T2D patients, which may be, in part, related to greater underlying systemic oxidative stress. Additionally, dynamic CA is blunted further with high intensity isometric contractions potentially placing T2D patients at greater risk for cerebral events during such activities. Copyright © 2015 the American Physiological Society.

  12. Cerebral autoregulation in the first day after preterm birth

    DEFF Research Database (Denmark)

    Hahn, Gitte Holst; Maroun, Lisa L; Larsen, Nanna Brink;

    2012-01-01

    Both systemic inflammation and impaired cerebral autoregulation (CA) have been associated with brain injury in preterm infants. We hypothesized that impaired CA represents a hemodynamic link between inflammation and brain injury.......Both systemic inflammation and impaired cerebral autoregulation (CA) have been associated with brain injury in preterm infants. We hypothesized that impaired CA represents a hemodynamic link between inflammation and brain injury....

  13. Impaired Cerebral Autoregulation during Head Up Tilt in Patients with Severe Brain Injury

    DEFF Research Database (Denmark)

    Riberholt, Christian Gunge; Olesen, Niels Damkjær; Thing, Mira;

    2016-01-01

    acquired brain injury and a low level of consciousness. Fourteen patients with severe acquired brain injury and orthostatic intolerance and fifteen healthy volunteers were enrolled. Blood pressure was evaluated by pulse contour analysis, heart rate and RR-intervals were determined by electrocardiography......, middle cerebral artery velocity was evaluated by transcranial Doppler, and near-infrared spectroscopy determined frontal lobe oxygenation in the supine position and during head-up tilt. Cerebral autoregulation was evaluated as the mean flow index calculated as the ratio between middle cerebral artery...

  14. Dopamine therapy is associated with impaired cerebral autoregulation in preterm infants

    DEFF Research Database (Denmark)

    Eriksen, Vibeke R; Hahn, Gitte H; Greisen, Gorm

    2014-01-01

    cerebral autoregulation (CA). METHODS: Near-infrared spectroscopy was used to measure the cerebral oxygenation index in 60 very preterm infants, and mean arterial blood pressure was monitored towards the end of their first day of life. Measurements were performed continuously for two to three hour periods....... CA was quantified as the cerebral oximetry index (COx). RESULTS: We treated 13 of the 60 infants (22%) with dopamine during the measurements. COx was higher in the dopamine group than the untreated group (0.41 ± 0.25 vs. 0.08 ± 0.25, p pressure tended to be lower in the dopamine group...

  15. Effects of desflurane on cerebral autoregulation.

    Science.gov (United States)

    Bedforth, N M; Girling, K J; Skinner, H J; Mahajan, R P

    2001-08-01

    The aim of this study was to determine the effects of desflurane, at 1 and 1.5 MAC, on cerebral autoregulation. Data were analysed from eight patients undergoing non-neurosurgical procedure. The blood flow velocity in the middle cerebral artery was measured by transcranial Doppler ultrasound and cerebral autoregulation was assessed by the transient hyperaemic response test. Partial pressure of the end-tidal carbon dioxide (PE'(CO(2))) and mean arterial pressure were measured throughout the study. Anaesthesia was induced with propofol and was maintained with desflurane at end-tidal concentrations of 7.4% (1 MAC) or 10.8% (1.5 MAC). The order of administration of the desflurane concentrations was determined randomly and a period of 15 min was allowed for equilibration at each concentration. The transient hyperaemic response tests were performed before induction of anaesthesia and after equilibration with each concentration of desflurane. An infusion of phenylephrine was used to maintain pre-induction mean arterial pressure and ventilation was adjusted to maintain the pre-induction value of PE'(CO(2)) throughout the study. Two indices derived from the transient hyperaemic response test (the transient hyperaemic response ratio and the strength of autoregulation) were used to assess cerebral autoregulation. Desflurane resulted in a marked and significant impairment in cerebral autoregulation; at concentrations of 1.5 MAC, autoregulation was almost abolished.

  16. Impaired autoregulation of cerebral blood flow in the distressed newborn infant

    DEFF Research Database (Denmark)

    Lou, H C; Lassen, N A; Friis-Hansen, B

    1979-01-01

    Cerebral blood flow was measured, using the 133Xe clearance technique, a few hours after birth in 19 infants with varying degrees of respiratory distress syndrome. Ten of these infants had had asphyxia at birth. The least affected infants with normotension (systolic blood pressure 60 to 65 mm Hg...... at birth and infants with RDS only. CBF varied considerably with spontaneous variations in blood pressure, suggesting that autoregulation was lacking. This finding may explain why distressed premature infants are prone to develop massive capillary bleeding in the germinal layer with penetration...

  17. Cerebellar and cerebral autoregulation in migraine.

    Science.gov (United States)

    Reinhard, Matthias; Schork, Joscha; Allignol, Arthur; Weiller, Cornelius; Kaube, Holger

    2012-04-01

    Silent ischemic brain lesions frequently occur in migraine with aura and are most often located in cerebellar border zones. This may imply an impairment of cerebellar blood flow autoregulation. This study investigated the characteristics of interictal cerebellar autoregulation in migraine with and without aura. Thirty-four patients (n=17, migraine without aura; n=17, migraine with aura) and 35 age- and sex-matched controls were studied. Triple simultaneous transcranial Doppler monitoring of one posterior inferior cerebellar artery, right posterior cerebral artery, and left middle cerebral artery was performed. Autoregulation dynamics were assessed from spontaneous blood pressure fluctuations (correlation coefficient index Dx) and from respiratory-induced 0.1-Hz blood pressure oscillations (phase and gain). Compared with controls, the autoregulatory index Dx was higher (indicating less autoregulation) in the posterior inferior cerebellar artery (P=0.0062) and middle cerebral artery (P=0.0078) in migraine with aura, but not in migraine without aura. Phase and gain did not significantly differ between migraine patients and controls. No significant associations of autoregulation with clinical factors were found, including frequency of migraine attacks and orthostatic intolerance. This first-time analysis of cerebellar autoregulation in migraine did not show a specific cerebellar dysautoregulation in the interictal period. More static autoregulatory properties (index Dx) are, however, impaired in persons with migraine with aura both in the cerebellar and anterior circulation. The cerebellar predilection of ischemic lesions in migraine with aura might be a combination of altered autoregulation and additional factors, such as the end artery cerebellar angioarchitecture.

  18. Cerebral Autoregulation in Stroke A Review of Transcranial Doppler Studies

    NARCIS (Netherlands)

    Aries, M.J.H.; Elting, Jan W.; De Keyser, Jacques; Kremer, Berry P. H.; Vroomen, Patrick C. A. J.

    2010-01-01

    Background and Purpose-Cerebral autoregulation may become impaired after stroke. To provide a review of the nature and extent of any autoregulation impairment after stroke and its course over time, a technique allowing repeated bedside measurements with good temporal resolution is required.

  19. Cerebral autoregulation in different hypertensive disorders of pregnancy

    NARCIS (Netherlands)

    van Veen, Teelkien R.; Panerai, Ronney B.; Haeri, Sina; Singh, Jasbir; Adusumalli, Jasvant A.; Zeeman, Gerda G.; Belfort, Michael A.

    2015-01-01

    OBJECTIVE: Cerebrovascular complications that are associated with hypertensive disorders of pregnancy (preeclampsia, chronic hypertension [CHTN], and gestational hypertension [GHTN]) are believed to be associated with impaired cerebral autoregulation, which is a physiologic process that maintains bl

  20. Chronically impaired autoregulation of cerebral blood flow in long-term diabetics

    DEFF Research Database (Denmark)

    Bentsen, N; Larsen, B; Lassen, N A

    1975-01-01

    of the patient. Regression analysis was carried out on the results in order to quantify autoregulatory capacity. In the control patients CBF did not vary with moderate blood pressure variations, indicating normal autoregulation. In four of the 16 diabetic patients CBF showed significant pressure dependency...

  1. 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...

  2. Human cerebral autoregulation before, during and after spaceflight.

    Science.gov (United States)

    Iwasaki, Ken-ichi; Levine, Benjamin D; Zhang, Rong; Zuckerman, Julie H; Pawelczyk, James A; Diedrich, André; Ertl, Andrew C; Cox, James F; Cooke, William H; Giller, Cole A; Ray, Chester A; Lane, Lynda D; Buckey, Jay C; Baisch, Friedhelm J; Eckberg, Dwain L; Robertson, David; Biaggioni, Italo; Blomqvist, C Gunnar

    2007-03-15

    Exposure to microgravity alters the distribution of body fluids and the degree of distension of cranial blood vessels, and these changes in turn may provoke structural remodelling and altered cerebral autoregulation. Impaired cerebral autoregulation has been documented following weightlessness simulated by head-down bed rest in humans, and is proposed as a mechanism responsible for postspaceflight orthostatic intolerance. In this study, we tested the hypothesis that spaceflight impairs cerebral autoregulation. We studied six astronauts approximately 72 and 23 days before, after 1 and 2 weeks in space (n = 4), on landing day, and 1 day after the 16 day Neurolab space shuttle mission. Beat-by-beat changes of photoplethysmographic mean arterial pressure and transcranial Doppler middle cerebral artery blood flow velocity were measured during 5 min of spontaneous breathing, 30 mmHg lower body suction to simulate standing in space, and 10 min of 60 deg passive upright tilt on Earth. Dynamic cerebral autoregulation was quantified by analysis of the transfer function between spontaneous changes of mean arterial pressure and cerebral artery blood flow velocity, in the very low- (0.02-0.07 Hz), low- (0.07-0.20 Hz) and high-frequency (0.20-0.35 Hz) ranges. Resting middle cerebral artery blood flow velocity did not change significantly from preflight values during or after spaceflight. Reductions of cerebral blood flow velocity during lower body suction were significant before spaceflight (P e.m.) cerebral blood flow velocity after 10 min upright tilt were smaller after than before spaceflight (absolute, -4 +/- 3 cm s(-1) after versus -14 +/- 3 cm s(-1) before, P = 0.001; and percentage, -8.0 +/- 4.8% after versus -24.8 +/- 4.4% before, P < 0.05), consistent with improved rather than impaired cerebral blood flow regulation. Low-frequency gain decreased significantly (P < 0.05) by 26, 23 and 27% after 1 and 2 weeks in space and on landing day, respectively, compared with

  3. Autoregulation of cerebral blood flow in experimental focal brain ischemia.

    Science.gov (United States)

    Dirnagl, U; Pulsinelli, W

    1990-05-01

    The relationship between systemic arterial pressure (SAP) and neocortical microcirculatory blood-flow (CBF) in areas of focal cerebral ischemia was studied in 15 spontaneously hypertensive rats (SHRs) anesthetized with halothane (0.5%). Ischemia was induced by ipsilateral middle cerebral artery/common carotid artery occlusion and CBF was monitored continuously in the ischemic territory using laser-Doppler flowmetry during manipulation of SAP with I-norepinephrine (hypertension) or nitroprusside (hypotension). In eight SHRs not subjected to focal ischemia, we demonstrated that 0.5% halothane and the surgical manipulations did not impair autoregulation. Autoregulation was partly preserved in ischemic brain tissue with a CBF of greater than 30% of preocclusion values. In areas where ischemic CBF was less than 30% of preocclusion values, autoregulation was completely lost. Changes in SAP had a greater influence on CBF in tissue areas where CBF ranged from 15 to 30% of baseline (9% change in CBF with each 10% change in SAP) than in areas where CBF was less than 15% of baseline (6% change in CBF with each 10% change in SAP). These findings demonstrate that the relationship between CBF and SAP in areas of focal ischemia is highly dependent on the severity of ischemia. Autoregulation is lost in a gradual manner until CBF falls below 30% of normal. In areas without autoregulation, the slope of the CBF/SAP relationship is inversely related to the degree of ischemia.

  4. Role of the altitude level on cerebral autoregulation in residents at high altitude.

    Science.gov (United States)

    Jansen, Gerard F A; Krins, Anne; Basnyat, Buddha; Odoom, Joseph A; Ince, Can

    2007-08-01

    Cerebral autoregulation is impaired in Himalayan high-altitude residents who live above 4,200 m. This study was undertaken to determine the altitude at which this impairment of autoregulation occurs. A second aim of the study was to test the hypothesis that administration of oxygen can reverse this impairment in autoregulation at high altitudes. In four groups of 10 Himalayan high-altitude dwellers residing at 1,330, 2,650, 3,440, and 4,243 m, arterial oxygen saturation (Sa(O(2))), blood pressure, and middle cerebral artery blood velocity were monitored during infusion of phenylephrine to determine static cerebral autoregulation. On the basis of these measurements, the cerebral autoregulation index (AI) was calculated. Normally, AI is between zero and 1. AI of 0 implies absent autoregulation, and AI of 1 implies intact autoregulation. At 1,330 m (Sa(O(2)) = 97%), 2,650 m (Sa(O(2)) = 96%), and 3,440 m (Sa(O(2)) = 93%), AI values (mean +/- SD) were, respectively, 0.63 +/- 0.27, 0.57 +/- 0.22, and 0.57 +/- 0.15. At 4,243 m (Sa(O(2)) = 88%), AI was 0.22 +/- 0.18 (P < 0.0005, compared with AI at the lower altitudes) and increased to 0.49 +/- 0.23 (P = 0.008, paired t-test) when oxygen was administered (Sa(O(2)) = 98%). In conclusion, high-altitude residents living at 4,243 m have almost total loss of cerebral autoregulation, which improved during oxygen administration. Those people living at 3,440 m and lower have still functioning cerebral autoregulation. This study showed that the altitude region between 3,440 and 4,243 m, marked by Sa(O(2)) in the high-altitude dwellers of 93% and 88%, is a transitional zone, above which cerebral autoregulation becomes critically impaired.

  5. Testing impact of perinatal inflammation on cerebral autoregulation in preterm neonates

    DEFF Research Database (Denmark)

    Hahn, Gitte Holst

    2013-01-01

    us to evaluate the precision and validity of this method. We monitored 22 preterm neonates and demonstrated that reliable detection of impaired cerebral autoregulation requires several hours of monitoring. However, weighting measurements with large variations in blood pressure in favour of those...... is impaired, cerebral blood flow follows changes in arterial blood pressure passively. Both impaired cerebral autoregulation and perinatal inflammation have been associated with perinatal brain injury in preterm neonates. We hypothesized that impaired cerebral autoregulation might represent a hemodynamic link...... between inflammation and brain injury. We used an apparently well established non-invasive method based on frequency analysis between spontaneous changes in arterial blood pressure and cerebral oxygenation as measured with near-infrared spectroscopy. It turned out that the methodology was weak. This led...

  6. Cerebral blood flow autoregulation in experimental liver failure

    DEFF Research Database (Denmark)

    Dethloff, T.J.; Larsen, F.S.; Knudsen, Gitte Moos

    2008-01-01

    Patients with acute liver failure (ALF) display impairment of cerebral blood flow (CBF) autoregulation, which may contribute to the development of fatal intracranial hypertension, but the pathophysiological mechanism remains unclear. In this study, we examined whether loss of liver mass causes...... impairment of CBF autoregulation. Four rat models were chosen, each representing different aspects of ALF: galactosamine (GlN) intoxication represented liver necrosis, 90% hepatectomy (PHx90) represented reduction in liver mass, portacaval anastomosis (PCA) represented shunting of blood....../toxins into the systemic circulation thus mimicking intrahepatic shunting in ALF, PCA+NH(3) provided information about the additional effects of hyperammonemia Rats were intubated and sedated with pentobarbital. We measured CBF with laser Doppler, intracranial pressure (ICP) was measured in the fossa posterior...

  7. Changes in cerebral autoregulation in the second half of pregnancy and compared to non-pregnant controls

    NARCIS (Netherlands)

    van Veen, Teelkien R.; Panerai, Ronney B.; Haeri, Sina; van den Berg, Paul P.; Zeeman, Gerda G.; Belfort, Michael A.

    2016-01-01

    Objective: The mechanism by which pregnancy affects the cerebral circulation is unknown, but it has a central role in the development of neurological complications in preeclampsia, which is believed to be related to impaired autoregulation. We evaluated the cerebral autoregulation in the second half

  8. Mathematical modelling of cerebral blood circulation and cerebral autoregulation: towards preventing intracranial hemorrhages in preterm newborns.

    Science.gov (United States)

    Lampe, Renée; Botkin, Nikolai; Turova, Varvara; Blumenstein, Tobias; Alves-Pinto, Ana

    2014-01-01

    Impaired cerebral autoregulation leads to fluctuations in cerebral blood flow, which can be especially dangerous for immature brain of preterm newborns. In this paper, two mathematical models of cerebral autoregulation are discussed. The first one is an enhancement of a vascular model proposed by Piechnik et al. We extend this model by adding a polynomial dependence of the vascular radius on the arterial blood pressure and adjusting the polynomial coefficients to experimental data to gain the autoregulation behavior. Moreover, the inclusion of a Preisach hysteresis operator, simulating a hysteretic dependence of the cerebral blood flow on the arterial pressure, is tested. The second model couples the blood vessel system model by Piechnik et al. with an ordinary differential equation model of cerebral autoregulation by Ursino and Lodi. An optimal control setting is proposed for a simplified variant of this coupled model. The objective of the control is the maintenance of the autoregulatory function for a wider range of the arterial pressure. The control can be interpreted as the effect of a medicament changing the cerebral blood flow by, for example, dilation of blood vessels. Advanced numerical methods developed by the authors are applied for the numerical treatment of the control problem.

  9. Mathematical Modelling of Cerebral Blood Circulation and Cerebral Autoregulation: Towards Preventing Intracranial Hemorrhages in Preterm Newborns

    Directory of Open Access Journals (Sweden)

    Renée Lampe

    2014-01-01

    Full Text Available Impaired cerebral autoregulation leads to fluctuations in cerebral blood flow, which can be especially dangerous for immature brain of preterm newborns. In this paper, two mathematical models of cerebral autoregulation are discussed. The first one is an enhancement of a vascular model proposed by Piechnik et al. We extend this model by adding a polynomial dependence of the vascular radius on the arterial blood pressure and adjusting the polynomial coefficients to experimental data to gain the autoregulation behavior. Moreover, the inclusion of a Preisach hysteresis operator, simulating a hysteretic dependence of the cerebral blood flow on the arterial pressure, is tested. The second model couples the blood vessel system model by Piechnik et al. with an ordinary differential equation model of cerebral autoregulation by Ursino and Lodi. An optimal control setting is proposed for a simplified variant of this coupled model. The objective of the control is the maintenance of the autoregulatory function for a wider range of the arterial pressure. The control can be interpreted as the effect of a medicament changing the cerebral blood flow by, for example, dilation of blood vessels. Advanced numerical methods developed by the authors are applied for the numerical treatment of the control problem.

  10. Regional cerebral blood flow autoregulation in patients with fulminant hepatic failure

    DEFF Research Database (Denmark)

    Larsen, Fin Stolze; Strauss, Gitte Irene; Møller, Kirsten;

    2000-01-01

    The absence of cerebral blood flow autoregulation in patients with fulminant hepatic failure (FHF) implies that changes in arterial pressure directly influence cerebral perfusion. It is assumed that dilatation of cerebral arterioles is responsible for the impaired autoregulation. Recently, frontal...... blood flow was reported to be lower compared with other brain regions, indicating greater arteriolar tone and perhaps preserved regional cerebral autoregulation. In patients with severe FHF (6 women, 1 man; median age, 46 years; range, 18 to 55 years), we tested the hypothesis that perfusion...... in the anterior cerebral artery would be less affected by an increase in mean arterial pressure compared with the brain area supplied by the middle cerebral artery. Relative changes in cerebral perfusion were determined by transcranial Doppler-measured mean flow velocity (V(mean)), and resistance was determined...

  11. Cerebral autoregulation in pregnancies complicated by diabetes and overweight

    NARCIS (Netherlands)

    van Veen, Teelkien R.; Panerai, Ronney B.; Haeri, Sina; van den Berg, Paul P.; Zeeman, Gerda G.; Belfort, Michael A.

    2015-01-01

    Aim: The aim of this study was to estimate the impact of diabetes and obesity on cerebral autoregulation in pregnancy. Methods: Cerebral autoregulation was evaluated in women with gestational diabetes, type 2 diabetes mellitus and/or overweight (body mass index >= 25kgm(-2)) and compared to a cohort

  12. [Should cerebral autoregulation be reassessed?

    DEFF Research Database (Denmark)

    Secher, Niels H.

    2009-01-01

    Maintained cardiac output (CO) and cerebral oxygenation (ScO2) are of importance for a reduction in perioperative complications. Normovolaemia is defined as a central blood volume that does not limit CO for the supine patient and is maintained by individualized goal directed fluid therapy. Thereb......, ScO2 is maintained even when the mean arterial pressure is pressure and it is recommended that ScO2 be monitored Udgivelsesdato: 2009/8/10...

  13. Cerebral blood flow autoregulation in patients with acute bacterial meningitis

    DEFF Research Database (Denmark)

    Møller, Kirsten

    2001-01-01

    Ph.d. afhandlingen omhandler sammenhængen mellem hjernens blodtilførsel (CBF) og middelarterietrykket (MAP) hos patienter med akut bakteriel meningitis. Hos raske er CBF uafhængig af MAP, hvilket kaldes CBF autoregulation. Svækket autoregulation antages at øge risikoen for cerebral hypoperfusion ...

  14. Altered phase interactions between spontaneous blood pressure and flow fluctuations in type 2 diabetes mellitus: Nonlinear assessment of cerebral autoregulation

    Science.gov (United States)

    Hu, Kun; Peng, C. K.; Huang, Norden E.; Wu, Zhaohua; Lipsitz, Lewis A.; Cavallerano, Jerry; Novak, Vera

    2008-04-01

    Cerebral autoregulation is an important mechanism that involves dilatation and constriction in arterioles to maintain relatively stable cerebral blood flow in response to changes of systemic blood pressure. Traditional assessments of autoregulation focus on the changes of cerebral blood flow velocity in response to large blood pressure fluctuations induced by interventions. This approach is not feasible for patients with impaired autoregulation or cardiovascular regulation. Here we propose a newly developed technique-the multimodal pressure-flow (MMPF) analysis, which assesses autoregulation by quantifying nonlinear phase interactions between spontaneous oscillations in blood pressure and flow velocity during resting conditions. We show that cerebral autoregulation in healthy subjects can be characterized by specific phase shifts between spontaneous blood pressure and flow velocity oscillations, and the phase shifts are significantly reduced in diabetic subjects. Smaller phase shifts between oscillations in the two variables indicate more passive dependence of blood flow velocity on blood pressure, thus suggesting impaired cerebral autoregulation. Moreover, the reduction of the phase shifts in diabetes is observed not only in previously-recognized effective region of cerebral autoregulation (type 2 diabetes mellitus alters cerebral blood flow regulation over a wide frequency range and that this alteration can be reliably assessed from spontaneous oscillations in blood pressure and blood flow velocity during resting conditions. We also show that the MMPF method has better performance than traditional approaches based on Fourier transform, and is more suitable for the quantification of nonlinear phase interactions between nonstationary biological signals such as blood pressure and blood flow.

  15. Effect of short-term hyperventilation on cerebral blood flow autoregulation in patients with acute bacterial meningitis

    DEFF Research Database (Denmark)

    Møller, Kirsten

    2000-01-01

    BACKGROUND AND PURPOSE: Cerebral blood flow (CBF) autoregulation is impaired in patients with acute bacterial meningitis: this may be caused by cerebral arteriolar dilatation. We tested the hypothesis that CBF autoregulation is recovered by acute mechanical hyperventilation in 9 adult patients...... with acute bacterial meningitis. METHODS: Norepinephrine was infused to increase mean arterial pressure (MAP) 30 mm Hg from baseline. Relative changes in CBF were concomitantly recorded by transcranial Doppler ultrasonography of the middle cerebral artery, measuring mean flow velocity (V...... completely during hyperventilation. The slope of the autoregulation curve decreased during hyperventilation compared with normoventilation (Pmeningitis, indicating...

  16. Impaired autoregulation of cerebral blood flow in long-term type I (insulin-dependent) diabetic patients with nephropathy and retinopathy

    DEFF Research Database (Denmark)

    Kastrup, J; Rørsgaard, S; Parving, H H;

    1986-01-01

    . Cerebral blood flow was measured by the intravenous 133Xenon method. Mean arterial blood pressure was elevated approximately 30 mmHg by intravenous infusion of angiotensin amide II and lowered about 10 mmHg by intravenous infusion of trimethaphan camsylate. In the control subjects the flow/pressure curve...... was horizontal indicating perfect autoregulation. In the diabetic patients the flow/pressure curve showed a significant slope with a 1.9% change in CBF per 10 mmHg change in mean arterial blood pressure as compared to a slope value of -0.4% in the control subjects (P less than 0.05). Our results confirm...

  17. Cerebral autoregulation control of blood flow in the brain

    CERN Document Server

    Payne, Stephen

    2016-01-01

    This Brief provides a comprehensive introduction to the control of blood flow in the brain. Beginning with the basic physiology of autoregulation, the author goes on to discuss measurement techniques, mathematical models, methods of analysis, and relevant clinical conditions, all within this single volume. The author draws together this disparate field, and lays the groundwork for future research directions. The text gives an up-to-date review of the state of the art in cerebral autoregulation, which is particularly relevant as cerebral autoregulation moves from the laboratory to the bedside. Cerebral Autoregulation will be useful to researchers in the physical sciences such as mathematical biology, medical physics, and biomedical engineering whose work is concerned with the brain. Researchers in the medical sciences and clinicians dealing with the brain and blood flow, as well as industry professionals developing techniques such as ultrasound, MRI, and CT will also find this Brief of interest.

  18. Cerebral autoregulation in subjects adapted and not adapted to high altitude.

    Science.gov (United States)

    Jansen, G F; Krins, A; Basnyat, B; Bosch, A; Odoom, J A

    2000-10-01

    Impaired cerebral autoregulation (CA) from high-altitude hypoxia may cause high-altitude cerebral edema in newcomers to a higher altitude. Furthermore, it is assumed that high-altitude natives have preserved CA. However, cerebral autoregulation has not been studied at altitude. We studied CA in 10 subjects at sea level and in 9 Sherpas and 10 newcomers at an altitude of 4243 m by evaluating the effect of an increase of mean arterial blood pressure (MABP) with phenylephrine infusion on the blood flow velocity in the middle cerebral artery (Vmca), using transcranial Doppler. Theoretically, no change of Vmca in response to an increase in MABP would imply perfect autoregulation. Complete loss of autoregulation is present if Vmca changes proportionally with changes of MABP. In the sea-level group, at a relative MABP increase of 23+/-4% during phenylephrine infusion, relative Vmca did not change essentially from baseline Vmca (2+/-7%, P=0.36), which indicated intact autoregulation. In the Sherpa group, at a relative MABP increase of 29+/-7%, there was a uniform and significant increase of Vmca of 24+/-9% (P<0.0001) from baseline Vmca, which indicated loss of autoregulation. The newcomers showed large variations of Vmca in response to a relative MABP increase of 21+/-6%. Five subjects showed increases of Vmca of 22% to 35%, and 2 subjects showed decreases of Vmca of 21% and 23%. All Sherpas and the majority of the newcomers showed impaired CA. It indicates that an intact autoregulatory response to changes in blood pressure is probably not a hallmark of the normal human cerebral vasculature at altitude and that impaired CA does not play a major role in the occurrence of cerebral edema in newcomers to the altitude.

  19. Multichannel near infrared spectroscopy indicates regional variations in cerebral autoregulation in infants supported on extracorporeal membrane oxygenation

    Science.gov (United States)

    Papademetriou, Maria D.; Tachtsidis, Ilias; Elliot, Martin J.; Hoskote, Aparna; Elwell, Clare E.

    2012-06-01

    Assessing noninvasively cerebral autoregulation, the protective mechanism of the brain to maintain constant cerebral blood flow despite changes in blood pressure, is challenging. Infants on life support system (ECMO) for cardiorespiratory failure are at risk of cerebral autoregulation impairment and consequent neurological problems. We measured oxyhaemoglobin concentration (HbO2) by multichannel (12 channels) near-infrared spectroscopy (NIRS) in six infants during sequential changes in ECMO flow. Wavelet cross-correlation (WCC) between mean arterial pressure (MAP) and HbO2 was used to construct a time-frequency representation of the concordance between the two signals to assess the nonstationary aspect of cerebral autoregulation and investigate regional variations. Group data showed that WCC increases with decreasing ECMO flow indicating higher concordance between MAP and HbO2 and demonstrating loss of cerebral autoregulation at low ECMO flows. Statistically significant differences in WCC were observed between channels placed on the right and left scalp with channels on the right exhibiting higher values of WCC suggesting that the right hemisphere was more susceptible to disruption of cerebral autoregulation. Multichannel NIRS in conjunction with wavelet analysis methods can be used to assess regional variations in dynamic cerebral autoregulation with important clinical application in the management of critically ill children on life support systems.

  20. Inhibition of nitric oxide synthesis following severe hypoxia-ischemia restores autoregulation of cerebral blood flow in newborn lambs

    NARCIS (Netherlands)

    Dorrepaal, CA; Steendijk, P; van Bel, F; Baan, J.

    Birth asphyxia impairs the autoregulatory ability of the cerebral blood flow. Inappropriate synthesis of vasodilatory nitric oxide may be important in this respect. We investigated if nitric oxide synthesis inhibition by N-omega-nitro-L-arginine (NLA) could restore cerebral autoregulation after

  1. Autoregulation of cerebral blood flow in orthostatic hypotension

    Science.gov (United States)

    Novak, V.; Novak, P.; Spies, J. M.; Low, P. A.

    1998-01-01

    BACKGROUND AND PURPOSE: We sought to evaluate cerebral autoregulation in patients with orthostatic hypotension (OH). METHODS: We studied 21 patients (aged 52 to 78 years) with neurogenic OH during 80 degrees head-up tilt. Blood flow velocities (BFV) from the middle cerebral artery were continuously monitored with transcranial Doppler sonography, as were heart rate, blood pressure (BP), cardiac output, stroke volume, CO2, total peripheral resistance, and cerebrovascular resistance. RESULTS: All OH patients had lower BP (PTPR (P.75) but with a flat slope. An expansion of the "autoregulated" range was seen in some patients. The OH_AF group was characterized by a profound fall in BFV in response to a small reduction in BP (mean deltaBP .75). CONCLUSIONS: The most common patterns of cerebral response to OH are autoregulatory failure with a flat flow-pressure relationship or intact autoregulation with an expanded autoregulated range. The least common pattern is autoregulatory failure with a steep flow-pressure relationship. Patients with patterns 1 and 2 have an enhanced capacity to cope with OH, while those with pattern 3 have reduced capacity.

  2. Comparison of Model-Based Indices of Cerebral Autoregulation and Vasomotor Reactivity Using Transcranial Doppler versus Near-Infrared Spectroscopy in Patients with Amnestic Mild Cognitive Impairment

    Science.gov (United States)

    Marmarelis, Vasilis Z.; Shin, Dae C.; Tarumi, Takashi; Zhang, Rong

    2016-01-01

    We recently introduced model-based “physiomarkers” of dynamic cerebral autoregulation and CO2 vasomotor reactivity as an aid for diagnosis of early-stage Alzheimer’s disease (AD) [1], where significant impairment of dynamic vasomotor reactivity (DVR) was observed in early-stage AD patients relative to age-matched controls. Milder impairment of DVR was shown in patients with amnestic mild cognitive impairment (MCI) using the same approach in a subsequent study [2]. The advocated approach utilizes subject-specific data-based models of cerebral hemodynamics to quantify the dynamic effects of resting-state changes in arterial blood pressure and end-tidal CO2 (the putative inputs) upon cerebral blood flow velocity (the putative output) measured at the middle cerebral artery via transcranial Doppler (TCD). The obtained input-output models are then used to compute model-based indices of DCA and DVR from model-predicted responses to an input pressure pulse or an input CO2 pulse, respectively. In this paper, we compare these model-based indices of DVR and DCA in 46 amnestic MCI patients, relative to 20 age-matched controls, using TCD measurements with their counterparts using Near-Infrared Spectroscopy (NIRS) measurements of blood oxygenation at the lateral prefrontal cortex in 43 patients and 22 age-matched controls. The goal of the study is to assess whether NIRS measurements can be used instead of TCD measurements to obtain model-based physiomarkers with comparable diagnostic utility. The results corroborate this view in terms of the ability of either output to yield model-based physiomarkers that can differentiate the group of aMCI patients from age-matched healthy controls. PMID:27911329

  3. Lipopolysaccharide infusion enhances dynamic cerebral autoregulation without affecting cerebral oxygen vasoreactivity in healthy volunteers

    DEFF Research Database (Denmark)

    Berg, Ronan Mg; Plovsing, Ronni R; Evans, Kevin A;

    2013-01-01

    Sepsis may be associated with disturbances in cerebral oxygen transport and cerebral haemodynamic function, thus rendering the brain particularly susceptible to hypoxia. The purpose of this study was to assess the impact of isocapnic hypoxia and hyperoxia on dynamic cerebral autoregulation...... in a human-experimental model of the systemic inflammatory response during the early stages of sepsis....

  4. Changes in cerebral autoregulation in the second half of pregnancy and compared to non-pregnant controls.

    Science.gov (United States)

    van Veen, Teelkien R; Panerai, Ronney B; Haeri, Sina; van den Berg, Paul P; Zeeman, Gerda G; Belfort, Michael A

    2016-10-01

    The mechanism by which pregnancy affects the cerebral circulation is unknown, but it has a central role in the development of neurological complications in preeclampsia, which is believed to be related to impaired autoregulation. We evaluated the cerebral autoregulation in the second half of pregnancy, and compared this with a control group of healthy, fertile non-pregnant women. In a prospective cohort analysis, cerebral blood flow velocity of the middle cerebral artery (determined by transcranial Doppler), blood pressure (noninvasive arterial volume clamping), and end-tidal carbon dioxide (EtCO2) were simultaneously collected for 7min. The autoregulation index (ARI) was calculated. ARI values of 0 and 9 indicated absent and perfect autoregulation, respectively. ANOVA and Pearson's correlation coefficient were used, with ppregnant and 18 non-pregnant women were included. The ARI did not change during pregnancy, but pregnant women had a significantly higher ARI than non-pregnant controls (ARI 6.7±0.9 vs. 5.3±1.4, ppregnant fertile women, even after controlling for EtCO2. The autoregulation does not change with advancing gestational age. Copyright © 2016 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved.

  5. Applicability of near-infrared spectroscopy to measure cerebral autoregulation noninvasively in neonates: a validation study in piglets

    DEFF Research Database (Denmark)

    Holst Hahn, Gitte; Heiring, Christian; Pryds, Ole;

    2011-01-01

    Impaired cerebral autoregulation (CA) is common and is associated with brain damage in sick neonates. Frequency analysis using spontaneous changes in arterial blood pressure (ABP) and cerebral near-infrared spectroscopy (NIRS) has been used to measure CA in several clinical studies. Coherence...... of the NIRS and ABP signals (i.e. correlation in the frequency domain) detects impairment of CA, whereas gain (i.e. magnitude of ABP variability passing from systemic to cerebral circulation) estimates the degree of this impairment. So far, however, this method has not been validated. In 12 newborn piglets...

  6. Cardiac baroreflex function and dynamic cerebral autoregulation in elderly Masters athletes

    NARCIS (Netherlands)

    Aengevaeren, V.L.; Claassen, J.A.H.R.; Levine, B.D.; Zhang, R.

    2013-01-01

    Cerebral blood flow (CBF) is stably maintained through the combined effects of blood pressure (BP) regulation and cerebral autoregulation. Previous studies suggest that aerobic exercise training improves cardiac baroreflex function and beneficially affects BP regulation, but may negatively affect ce

  7. Secondary decline of cerebral autoregulation is associated with worse outcome after intracerebral hemorrhage

    DEFF Research Database (Denmark)

    Reinhard, Matthias; Neunhoeffer, Florian; Gerds, Thomas A

    2010-01-01

    and 5 after ictus. Autoregulation was noninvasively measured from spontaneous fluctuations of blood pressure and middle cerebral artery flow velocity (assessed by transcranial Doppler) using the correlation coefficient index Mx. From the same signals, non-invasive cerebral perfusion pressure...

  8. A stochastic delay differential model of cerebral autoregulation.

    Science.gov (United States)

    Panunzi, Simona; D'Orsi, Laura; Iacoviello, Daniela; De Gaetano, Andrea

    2015-01-01

    Mathematical models of the cardiovascular system and of cerebral autoregulation (CAR) have been employed for several years in order to describe the time course of pressures and flows changes subsequent to postural changes. The assessment of the degree of efficiency of cerebral auto regulation has indeed importance in the prognosis of such conditions as cerebro-vascular accidents or Alzheimer. In the quest for a simple but realistic mathematical description of cardiovascular control, which may be fitted onto non-invasive experimental observations after postural changes, the present work proposes a first version of an empirical Stochastic Delay Differential Equations (SDDEs) model. The model consists of a total of four SDDEs and two ancillary algebraic equations, incorporates four distinct delayed controls from the brain onto different components of the circulation, and is able to accurately capture the time course of mean arterial pressure and cerebral blood flow velocity signals, reproducing observed auto-correlated error around the expected drift.

  9. A Stochastic Delay Differential Model of Cerebral Autoregulation

    Science.gov (United States)

    Panunzi, Simona; D’Orsi, Laura; Iacoviello, Daniela; De Gaetano, Andrea

    2015-01-01

    Mathematical models of the cardiovascular system and of cerebral autoregulation (CAR) have been employed for several years in order to describe the time course of pressures and flows changes subsequent to postural changes. The assessment of the degree of efficiency of cerebral auto regulation has indeed importance in the prognosis of such conditions as cerebro-vascular accidents or Alzheimer. In the quest for a simple but realistic mathematical description of cardiovascular control, which may be fitted onto non-invasive experimental observations after postural changes, the present work proposes a first version of an empirical Stochastic Delay Differential Equations (SDDEs) model. The model consists of a total of four SDDEs and two ancillary algebraic equations, incorporates four distinct delayed controls from the brain onto different components of the circulation, and is able to accurately capture the time course of mean arterial pressure and cerebral blood flow velocity signals, reproducing observed auto-correlated error around the expected drift. PMID:25830915

  10. A stochastic delay differential model of cerebral autoregulation.

    Directory of Open Access Journals (Sweden)

    Simona Panunzi

    Full Text Available Mathematical models of the cardiovascular system and of cerebral autoregulation (CAR have been employed for several years in order to describe the time course of pressures and flows changes subsequent to postural changes. The assessment of the degree of efficiency of cerebral auto regulation has indeed importance in the prognosis of such conditions as cerebro-vascular accidents or Alzheimer. In the quest for a simple but realistic mathematical description of cardiovascular control, which may be fitted onto non-invasive experimental observations after postural changes, the present work proposes a first version of an empirical Stochastic Delay Differential Equations (SDDEs model. The model consists of a total of four SDDEs and two ancillary algebraic equations, incorporates four distinct delayed controls from the brain onto different components of the circulation, and is able to accurately capture the time course of mean arterial pressure and cerebral blood flow velocity signals, reproducing observed auto-correlated error around the expected drift.

  11. Dynamic cerebral autoregulation changes during sub-maximal handgrip maneuver.

    Directory of Open Access Journals (Sweden)

    Ricardo C Nogueira

    Full Text Available PURPOSE: We investigated the effect of handgrip (HG maneuver on time-varying estimates of dynamic cerebral autoregulation (CA using the autoregressive moving average technique. METHODS: Twelve healthy subjects were recruited to perform HG maneuver during 3 minutes with 30% of maximum contraction force. Cerebral blood flow velocity, end-tidal CO₂ pressure (PETCO₂, and noninvasive arterial blood pressure (ABP were continuously recorded during baseline, HG and recovery. Critical closing pressure (CrCP, resistance area-product (RAP, and time-varying autoregulation index (ARI were obtained. RESULTS: PETCO₂ did not show significant changes during HG maneuver. Whilst ABP increased continuously during the maneuver, to 27% above its baseline value, CBFV raised to a plateau approximately 15% above baseline. This was sustained by a parallel increase in RAP, suggestive of myogenic vasoconstriction, and a reduction in CrCP that could be associated with metabolic vasodilation. The time-varying ARI index dropped at the beginning and end of the maneuver (p<0.005, which could be related to corresponding alert reactions or to different time constants of the myogenic, metabolic and/or neurogenic mechanisms. CONCLUSION: Changes in dynamic CA during HG suggest a complex interplay of regulatory mechanisms during static exercise that should be considered when assessing the determinants of cerebral blood flow and metabolism.

  12. Cerebral blood flow autoregulation in hypertension and effects of antihypertensive drugs

    DEFF Research Database (Denmark)

    Barry, David; Lassen, N A

    1984-01-01

    If antihypertensive treatment, especially emergency blood pressure lowering, is always to be safe, more thought should be given to autoregulation of cerebral blood in the hypertensive patient. This topic is reviewed in the present article, in the hypertensive patient. This topic is reviewed...... in the present article, particular emphasis being placed on the resetting of the lower limit of autoregulation to higher pressure in hypertension and the effects of acute administration of anti-hypertensive drugs on CBF and CBF-autoregulation....

  13. Dynamic cerebral autoregulation to induced blood pressure changes in human experimental and clinical sepsis.

    Science.gov (United States)

    Berg, Ronan M G; Plovsing, Ronni R; Bailey, Damian M; Holstein-Rathlou, Niels-Henrik; Møller, Kirsten

    2016-11-01

    Previous studies have demonstrated that dynamic cerebral autoregulation to spontaneous fluctuations in blood pressure is enhanced following lipopolysaccharide (LPS) infusion, a human experimental model of early sepsis, whereas by contrast it is impaired in patients with severe sepsis or septic shock. In this study, we hypothesized that this pattern of response would be identical during induced changes in blood pressure. Dynamic cerebral autoregulation was assessed in nine healthy volunteers and six septic patients. The healthy volunteers underwent a 4-h intravenous infusion of LPS (total dose: 2 ng kg(-1) ). Mean arterial blood pressure (MAP, arterial transducer) and middle cerebral artery blood flow velocity (MCAv, transcranial Doppler ultrasound) were recorded continuously during thigh-cuff deflation-induced changes in MAP for the determination of a modified rate of regulation (RoR). This was performed before and after LPS infusion in healthy volunteers, and within 72 h following clinical diagnosis of sepsis in patients. In healthy volunteers, thigh-cuff deflation caused a MAP reduction of 16 (13-20) % at baseline and 18 (16-20) % after LPS, while the MAP reduction was 12 (11-13) % in patients (Psepsis, they remain inconclusive with regard to more advanced stages of disease, because thigh-cuff deflation failed to induce sufficient MAP reductions in patients. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  14. Cerebral autoregulation in awake versus isoflurane-anesthetized rats.

    Science.gov (United States)

    Hoffman, W E; Edelman, G; Kochs, E; Werner, C; Segil, L; Albrecht, R F

    1991-12-01

    We evaluated regional cerebral and spinal cord blood flow in rats during isoflurane anesthesia. Tissue blood flow was measured in cerebral cortex, subcortex, midbrain, and spinal cord using radioactive microspheres. Blood flow autoregulation was measured within the following arterial blood pressure ranges (mm Hg): 1 = less than 50, 2 = 50-90, 3 = 90-130, 4 = 130-170, 5 = greater than 170. Arterial blood pressure was increased using phenylephrine infusion and decreased with ganglionic blockade and hemorrhage. Three treatment groups were studied: 1 = awake control, 2 = 1.0 minimum alveolar anesthetic concentration (MAC) isoflurane, 3 = 2.0 MAC isoflurane. Autoregulation was seen in awake rats from 50 to 170 mm Hg in all tissues. The autoregulatory coefficient (change in blood flow/change in blood pressure) was increased in midbrain and spinal cord during 1.0 MAC isoflurane and in all tissues during 2.0 MAC isoflurane (P less than 0.05). Within the arterial blood pressure range of 90-130 mm Hg, isoflurane produced the following changes in tissue blood flow (percent of awake control): 1.0 MAC isoflurane: cortex = 87% +/- 8% (P greater than 0.30), subcortex = 124% +/- 11% (P greater than 0.05), midbrain = 263% +/- 20% (P less than 0.001), spinal cord = 278% +/- 19% (P less than 0.001); 2.0 MAC isoflurane: cortex = 137% +/- 13% (P less than 0.05), subcortex = 272% +/- 24% (P less than 0.001), midbrain = 510% +/- 53% (P less than 0.001), spinal cord = 535% +/- 50% (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Cerebral autoregulation and symptoms of orthostatic hypotension in familial dysautonomia.

    Science.gov (United States)

    Fuente Mora, Cristina; Palma, Jose-Alberto; Kaufmann, Horacio; Norcliffe-Kaufmann, Lucy

    2017-07-01

    Familial dysautonomia is an inherited autonomic disorder with afferent baroreflex failure. We questioned why despite low blood pressure standing, surprisingly few familial dysautonomia patients complain of symptomatic hypotension or have syncope. Using transcranial Doppler ultrasonography of the middle cerebral artery, we measured flow velocity (mean, peak systolic, and diastolic), area under the curve, pulsatility index, and height of the dictrotic notch in 25 patients with familial dysautonomia and 15 controls. In patients, changing from sitting to a standing position, decreased BP from 124 ± 4/64 ± 3 to 82 ± 3/37 ± 2 mmHg (p < 0.0001, for both). Despite low BP, all patients denied orthostatic symptoms. Middle cerebral artery velocity fell minimally, and the magnitude of the reductions were similar to those observed in healthy controls, in whom BP upright did not fall. While standing, patients had a greater fall in cerebrovascular resistance (p < 0.0001), an increase in pulsatility (p < 0.0001), and a deepening of the dicrotic notch (p = 0.0010), findings all consistent with low cerebrovascular resistance. No significant changes occurred in controls. Patients born with baroreflex deafferentation retain the ability to buffer wide fluctuations in BP and auto-regulate cerebral blood flow. This explains how they can tolerate extremely low BPs standing that would otherwise induce syncope.

  16. Transfer function analysis of dynamic cerebral autoregulation in humans

    Science.gov (United States)

    Zhang, R.; Zuckerman, J. H.; Giller, C. A.; Levine, B. D.; Blomqvist, C. G. (Principal Investigator)

    1998-01-01

    To test the hypothesis that spontaneous changes in cerebral blood flow are primarily induced by changes in arterial pressure and that cerebral autoregulation is a frequency-dependent phenomenon, we measured mean arterial pressure in the finger and mean blood flow velocity in the middle cerebral artery (VMCA) during supine rest and acute hypotension induced by thigh cuff deflation in 10 healthy subjects. Transfer function gain, phase, and coherence function between changes in arterial pressure and VMCA were estimated using the Welch method. The impulse response function, calculated as the inverse Fourier transform of this transfer function, enabled the calculation of transient changes in VMCA during acute hypotension, which was compared with the directly measured change in VMCA during thigh cuff deflation. Beat-to-beat changes in VMCA occurred simultaneously with changes in arterial pressure, and the autospectrum of VMCA showed characteristics similar to arterial pressure. Transfer gain increased substantially with increasing frequency from 0.07 to 0.20 Hz in association with a gradual decrease in phase. The coherence function was > 0.5 in the frequency range of 0.07-0.30 Hz and transfer function with the quality of a high-pass filter in the frequency range of 0.07-0.30 Hz.

  17. Cerebral autoregulation in the preterm newborn using near-infrared spectroscopy

    DEFF Research Database (Denmark)

    Eriksen, Vibeke R; Hahn, Gitte H; Greisen, Gorm

    2015-01-01

    The aim was to compare two conventional methods used to describe cerebral autoregulation (CA): frequency-domain analysis and time-domain analysis. We measured cerebral oxygenation (as a surrogate for cerebral blood flow) and mean arterial blood pressure (MAP) in 60 preterm infants. In the frequency...

  18. Transfer function analysis for the assessment of cerebral autoregulation using spontaneous oscillations in blood pressure and cerebral blood flow

    NARCIS (Netherlands)

    Abeelen, A.S.S. van den; Beek, A.H. van; Slump, C.H.; Panerai, R.B.; Claassen, J.A.H.R.

    2014-01-01

    Cerebral autoregulation (CA) is a key mechanism to protect the brain against excessive fluctuations in blood pressure (BP) and maintain cerebral blood flow. Analyzing the relationship between spontaneous BP and cerebral blood flow velocity (CBFV) using transfer function analysis is a widely used tec

  19. Wavelet coherence analysis of dynamic cerebral autoregulation in neonatal hypoxic–ischemic encephalopathy

    Directory of Open Access Journals (Sweden)

    Fenghua Tian

    2016-01-01

    Full Text Available Cerebral autoregulation represents the physiological mechanisms that keep brain perfusion relatively constant in the face of changes in blood pressure and thus plays an essential role in normal brain function. This study assessed cerebral autoregulation in nine newborns with moderate-to-severe hypoxic–ischemic encephalopathy (HIE. These neonates received hypothermic therapy during the first 72 h of life while mean arterial pressure (MAP and cerebral tissue oxygenation saturation (SctO2 were continuously recorded. Wavelet coherence analysis, which is a time-frequency domain approach, was used to characterize the dynamic relationship between spontaneous oscillations in MAP and SctO2. Wavelet-based metrics of phase, coherence and gain were derived for quantitative evaluation of cerebral autoregulation. We found cerebral autoregulation in neonates with HIE was time-scale-dependent in nature. Specifically, the spontaneous changes in MAP and SctO2 had in-phase coherence at time scales of less than 80 min (<0.0002 Hz in frequency, whereas they showed anti-phase coherence at time scales of around 2.5 h (~0.0001 Hz in frequency. Both the in-phase and anti-phase coherence appeared to be related to worse clinical outcomes. These findings suggest the potential clinical use of wavelet coherence analysis to assess dynamic cerebral autoregulation in neonatal HIE during hypothermia.

  20. Detection of cerebral autoregulation by near-infrared spectroscopy in neonates: performance analysis of measurement methods

    Science.gov (United States)

    Caicedo, Alexander; Naulaers, Gunnar; Lemmers, Petra; van Bel, Frank; Wolf, Martin; Van Huffel, Sabine

    2012-11-01

    Cerebral Autoregulation, in clinical practice, is assessed by means of correlation or coherence analysis between mean arterial blood pressure (MABP) and cerebral blood flow (CBF). However, even though there is evidence linking cerebral autoregulation assessment with clinical outcome in preterm infants, available methods lack precision for clinical use. Classical methods, used for cerebral autoregulation, are influenced by the choice of parameters such as the length of the epoch under analysis and the choice of suitable frequency bands. The influence of these parameters, in the derived measurements for cerebral autoregulation, has not yet been evaluated. In this study, cerebral autoregulation was assessed using correlation, coherence, a modified version of coherence and transfer function gain, and phase. The influence of the extra-parameters on the final scores was evaluated by means of sensitivity analysis. The methods were applied to a database of 18 neonates with measurements of MABP and tissue oxygenation index (TOI). TOI reflects changes in CBF and was measured by means of near-infrared spectroscopy.

  1. Cerebral autoregulation dynamics in endurance-trained individuals

    DEFF Research Database (Denmark)

    Lind-Holst, Mikkel; Cotter, James D; Helge, Jørn W;

    2011-01-01

    of increase in the cerebrovascular conductance index (CVCi = MCA V(mean)/MAP) appeared later in the athletes (3.9 ± 0.4 vs. 2.7 ± 0.4s, P = 0.01). Spectral analysis revealed a normal MAP-to-MCA V(mean) phase in both groups but ~40% higher normalized MAP to MCA V(mean) low-frequency transfer function gain...... in untrained subjects and was associated with parallel changes in indexes of cerebral blood flow. Once initiated, the autoregulatory response was similar between the groups. A delayed onset of autoregulation with a larger normalized transfer gain conforms with a less effective dampening of MAP oscillations...... pressure (MAP) after 2.5 min of leg ischemia in endurance athletes and untrained subjects (maximal O(2) uptake: 69 ± 7 vs. 42 ± 5 ml O(2)·min(-1)·kg(-1); n = 9 for both, means ± SE). After cuff release when seated, endurance athletes had larger drops in MAP (94 ± 6 to 62 ± 5 mmHg, -39%, vs. 99 ± 5 to 73...

  2. Autoregulation of cerebral blood flow to changes in arterial pressure in mild Alzheimer's disease.

    Science.gov (United States)

    Zazulia, Allyson R; Videen, Tom O; Morris, John C; Powers, William J

    2010-11-01

    Studies in transgenic mice overexpressing amyloid precursor protein (APP) demonstrate impaired autoregulation of cerebral blood flow (CBF) to changes in arterial pressure and suggest that cerebrovascular dysfunction may be critically important in the development of pathological Alzheimer's disease (AD). Given the relevance of such a finding for guiding hypertension treatment in the elderly, we assessed autoregulation in individuals with AD. Twenty persons aged 75±6 years with very mild or mild symptomatic AD (Clinical Dementia Rating 0.5 or 1.0) underwent (15)O-positron emission tomography (PET) CBF measurements before and after mean arterial pressure (MAP) was lowered from 107±13 to 92±9 mm Hg with intravenous nicardipine; (11)C-PIB-PET imaging and magnetic resonance imaging (MRI) were also obtained. There were no significant differences in mean CBF before and after MAP reduction in the bilateral hemispheres (-0.9±5.2 mL per 100 g per minute, P=0.4, 95% confidence interval (CI)=-3.4 to 1.5), cortical borderzones (-1.9±5.0 mL per 100 g per minute, P=0.10, 95% CI=-4.3 to 0.4), regions of T2W-MRI-defined leukoaraiosis (-0.3±4.4 mL per 100 g per minute, P=0.85, 95% CI=-3.3 to 3.9), or regions of peak (11)C-PIB uptake (-2.5±7.7 mL per 100 g per minute, P=0.30, 95% CI=-7.7 to 2.7). The absence of significant change in CBF with a 10 to 15 mm Hg reduction in MAP within the normal autoregulatory range demonstrates that there is neither a generalized nor local defect of autoregulation in AD.

  3. No effect of angiotensin II AT(2)-receptor antagonist PD 123319 on cerebral blood flow autoregulation

    DEFF Research Database (Denmark)

    Estrup, T M; Paulson, O B; Strandgaard, S

    2001-01-01

    Blockade of the renin-angiotensin system with angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin AT1-receptor antagonists shift the limits of autoregulation of cerebral blood flow (CBF) towards lower blood pressure (BP). The role of AT2-receptors in the regulation of the cerebral cir...

  4. No effect of angiotensin II AT(2)-receptor antagonist PD 123319 on cerebral blood flow autoregulation

    DEFF Research Database (Denmark)

    Estrup, T M; Paulson, O B; Strandgaard, S

    2001-01-01

    Blockade of the renin-angiotensin system with angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin AT1-receptor antagonists shift the limits of autoregulation of cerebral blood flow (CBF) towards lower blood pressure (BP). The role of AT2-receptors in the regulation of the cerebral...

  5. Endotoxemia reduces cerebral perfusion but enhances dynamic cerebrovascular autoregulation at reduced arterial carbon dioxide tension*

    DEFF Research Database (Denmark)

    Brassard, Patrice; Kim, Yu-Sok; van Lieshout, Johannes

    2012-01-01

    OBJECTIVE:: The administration of endotoxin to healthy humans reduces cerebral blood flow but its influence on dynamic cerebral autoregulation remains unknown. We considered that a reduction in arterial carbon dioxide tension would attenuate cerebral perfusion and improve dynamic cerebral......-104] mm Hg; p = .75), but increased cardiac output (8.3 [6.1-9.5] L·min vs. 6.0 [4.5-8.2] L·min; p = .02) through an elevation in heart rate (82 ± 9 beats·min vs. 63 ± 10 beats·min; p arterial carbon dioxide tension (37 ± 5 mm Hg vs. 41 ± 2 mm Hg; p artery mean...... in arterial carbon dioxide tension explains the improved dynamic cerebral autoregulation and the reduced cerebral perfusion encountered in healthy subjects during endotoxemia....

  6. Dopamine therapy does not affect cerebral autoregulation during hypotension in newborn piglets.

    Science.gov (United States)

    Eriksen, Vibeke Ramsgaard; Rasmussen, Martin Bo; Hahn, Gitte Holst; Greisen, Gorm

    2017-01-01

    Hypotensive neonates who have been treated with dopamine have poorer neurodevelopmental outcome than those who have not been treated with dopamine. We speculate that dopamine stimulates adrenoceptors on cerebral arteries causing cerebral vasoconstriction. This vasoconstriction might lead to a rightward shift of the cerebral autoregulatory curve; consequently, infants treated with dopamine would have a higher risk of low cerebral blood flow at a blood pressure that is otherwise considered "safe". In anaesthetized piglets, perfusion of the brain, monitored with laser-doppler flowmetry, and cerebral venous saturation was measured at different levels of hypotension. Each piglet was studied in two phases: a phase with stepwise decreases in MAP and a phase with stepwise increases in MAP. We randomized the order of the two phases, whether dopamine was given in the first or second phase, and the infusion rate of dopamine (10, 25, or 40 μg/kg/min). In/deflation of a balloon catheter, placed in vena cava, induced different levels of hypotension. At each level of hypotension, fluctuations in MAP were induced by in/deflations of a balloon catheter in descending aorta. During measurements, PaCO2 and arterial saturation were stable. MAP levels ranged between 14 and 82 mmHg. Cerebral autoregulation (CA) capacity was calculated as the ratio between %-change in cerebrovascular resistance and %-change in MAP induced by the in/deflation of the arterial balloon. A breakpoint in CA capacity was identified at a MAP of 38±18 mmHg without dopamine and at 44±18, 31±14, and 24±14 mmHg with dopamine infusion rates of 10, 25, and 40 μg/kg/min (p = 0.057). Neither the index of steady-state cerebral perfusion nor cerebral venous saturation were affected by dopamine infusion. Dopamine infusion tended to improve CA capacity at low blood pressures while an index of steady-state cerebral blood flow and cerebral venous saturation were unaffected by dopamine infusion. Thus, dopamine does not

  7. Effect of pregnancy on autoregulation of cerebral blood flow in anterior versus posterior cerebrum.

    Science.gov (United States)

    Cipolla, Marilyn J; Bishop, Nicole; Chan, Siu-Lung

    2012-09-01

    Severe preeclampsia and eclampsia are associated with brain edema that forms preferentially in the posterior cerebral cortex possibly because of decreased sympathetic innervation of posterior cerebral arteries and less effective autoregulation during acute hypertension. In the present study, we examined the effect of pregnancy on the effectiveness of cerebral blood flow autoregulation using laser Doppler flowmetry and edema formation by wet:dry weight in acute hypertension induced by phenylephrine infusion in the anterior and posterior cerebrum from nonpregnant (n=8) and late-pregnant (n=6) Sprague-Dawley rats. In addition, we compared the effect of pregnancy on sympathetic innervation by tyrosine hydroxylase staining of posterior and middle cerebral arteries (n=5-6 per group) and endothelial and neuronal NO synthase expression using quantitative PCR (n=3 per group). In nonpregnant animals, there was no difference in autoregulation between the anterior and posterior cerebrum. However, in late-pregnant animals, the threshold of cerebral blood flow autoregulation was shifted to lower pressures in the posterior cerebrum, which was associated with increased neuronal NO synthase expression in the posterior cerebral cortex versus anterior. Compared with the nonpregnant state, pregnancy increased the threshold of autoregulation in both brain regions that was related to decreased expression of endothelial NO synthase. Lastly, acute hypertension during pregnancy caused greater edema formation in both brain cortices that was not attributed to changes in sympathetic innervation. These findings suggest that, although pregnancy shifted the cerebral blood flow autoregulatory curve to higher pressures in both the anterior and posterior cortices, it did not protect from edema during acute hypertension.

  8. Effect of pregnancy and nitric oxide on the myogenic vasodilation of posterior cerebral arteries and the lower limit of cerebral blood flow autoregulation.

    Science.gov (United States)

    Chapman, Abbie C; Cipolla, Marilyn J; Chan, Siu-Lung

    2013-09-01

    Hemorrhage during parturition can lower blood pressure beyond the lower limit of cerebral blood flow (CBF) autoregulation that can cause ischemic brain injury. However, the impact of pregnancy on the lower limit of CBF autoregulation is unknown. We measured myogenic vasodilation, a major contributor of CBF autoregulation, in isolated posterior cerebral arteries (PCAs) from nonpregnant and late-pregnant rats (n = 10/group) while the effect of pregnancy on the lower limit of CBF autoregulation was studied in the posterior cerebral cortex during controlled hemorrhage (n = 8). Pregnancy enhanced myogenic vasodilation in PCA and shifted the lower limit of CBF autoregulation to lower pressures. Inhibition of nitric oxide synthase (NOS) prevented the enhanced myogenic vasodilation during pregnancy but did not affect the lower limit of CBF autoregulation. The shift in the autoregulatory curve to lower pressures during pregnancy is likely protective of ischemic injury during hemorrhage and appears to be independent of NOS.

  9. Applicability of near-infrared spectroscopy to measure cerebral autoregulation noninvasively in neonates: a validation study in piglets

    DEFF Research Database (Denmark)

    Holst Hahn, Gitte; Heiring, Christian; Pryds, Ole;

    2011-01-01

    , we compared NIRS-derived measures of CA with a conventional measure of CA: cerebral blood flow was measured by laser Doppler flowmetry, and changes in ABP were induced by inflating a thoracic aorta balloon. CA capacity was calculated as %¿CVR/%¿ABP (i.e. percentage of full autoregulatory capacity......Impaired cerebral autoregulation (CA) is common and is associated with brain damage in sick neonates. Frequency analysis using spontaneous changes in arterial blood pressure (ABP) and cerebral near-infrared spectroscopy (NIRS) has been used to measure CA in several clinical studies. Coherence...... capacity in measurements with significant coherence (r = -0.55, n = 15, p = 0.03). In conclusion, our data validate frequency analysis for estimation of CA in clinical research. Low precision, however, hampers its clinical application....

  10. Dopamine therapy does not affect cerebral autoregulation during hypotension in newborn piglets

    DEFF Research Database (Denmark)

    Eriksen, Vibeke Ramsgaard; Rasmussen, Martin Bo; Hahn, Gitte Holst

    2017-01-01

    measurements, PaCO2 and arterial saturation were stable. MAP levels ranged between 14 and 82 mmHg. Cerebral autoregulation (CA) capacity was calculated as the ratio between %-change in cerebrovascular resistance and %-change in MAP induced by the in/deflation of the arterial balloon. A breakpoint in CA...

  11. [A five-element lumped-parameter model for cerebral blood flow autoregulation].

    Science.gov (United States)

    Wang, Shengzhang; Yao, Wei; Ding, Guanghong

    2009-10-01

    Utilizing the third-order polynomial curve fitted to the experimental data, which represents the relationship between cerebral blood flow (CBF) and mean artery blood pressure (MABP), we constructed a lumped-parameter dynamic model with 5 elements. In this model; the resistance is not constants it is determined by the fitted curve. We simulated the process of CBF autoregulation numerically by solving the govern equation of this model and got quite accurate results. Furthermore, we studied the influence of hemodynamic parameters on the CBF autoregulation by this model and proved that the characteristic resistance is the most important factor.

  12. Precision of coherence analysis to detect cerebral autoregulation by near-infrared spectroscopy in preterm infants

    DEFF Research Database (Denmark)

    Hahn, GH; Christensen, KB; Leung, TS;

    2010-01-01

    Coherence between spontaneous fluctuations in arterial blood pressure (ABP) and the cerebral near-infrared spectroscopy signal can detect cerebral autoregulation. Because reliable measurement depends on signals with high signal-to-noise ratio, we hypothesized that coherence is more precisely...... for the variabilityABP among repeated measurements (i.e., weighting measurements with high variabilityABP in favor of those with low) improved the precision. The evidence of drift in individual infants was weak. Minimum monitoring time needed to discriminate among infants was 1.3–3.7 h. Coherence analysis in low...... frequencies (0.04–0.1 Hz) had higher precision and statistically more power than in very low frequencies (0.003–0.04 Hz). In conclusion, a reliable detection of cerebral autoregulation takes hours and the precision is improved by adjusting for variabilityABP between repeated measurements....

  13. Effects of autoregulation and CO2 reactivity on cerebral oxygen transport.

    Science.gov (United States)

    Payne, S J; Selb, J; Boas, D A

    2009-11-01

    Both autoregulation and CO(2) reactivity are known to have significant effects on cerebral blood flow and thus on the transport of oxygen through the vasculature. In this paper, a previous model of the autoregulation of blood flow in the cerebral vasculature is expanded to include the dynamic behavior of oxygen transport through binding with hemoglobin. The model is used to predict the transfer functions for both oxyhemoglobin and deoxyhemoglobin in response to fluctuations in arterial blood pressure and arterial CO(2) concentration. It is shown that only six additional nondimensional groups are required in addition to the five that were previously found to characterize the cerebral blood flow response. A resonant frequency in the pressure-oxyhemoglobin transfer function is found to occur in the region of 0.1 Hz, which is a frequency of considerable physiological interest. The model predictions are compared with results from the published literature of phase angle at this frequency, showing that the effects of changes in breathing rate can significantly alter the inferred phase dynamics between blood pressure and hemoglobin. The question of whether dynamic cerebral autoregulation is affected under conditions of stenosis or stroke is then examined.

  14. Laser Doppler flowmetry is valid for measurement of cerebral blood flow autoregulation lower limit in rats

    DEFF Research Database (Denmark)

    Tonnesen, Jan; Pryds, Anders; Larsen, Erik Hviid

    2005-01-01

    Laser Doppler flowmetry (LDF) is a recent technique that is increasingly being used to monitor relative changes in cerebral blood flow whereas the intra-arterial 133xenon injection technique is a well-established method for repeated absolute measurements of cerebral blood flow. The aim of this st...... CO2 challenge. Haemodilution influences the two methods differently causing relative overestimation of blood flow by the laser Doppler technique compared to the 133xenon method....... of this study was to validate LDF for assessment of cerebral autoregulation and CO2 reactivity with the 133xenon injection technique as the gold standard. Simultaneous measurements of cerebral blood flow (CBF) were collected by LDF (CBFLDF) and the 133xenon method (CBFXe) while (1) cerebral autoregulation...... was challenged by controlled systemic haemorrhage, or (2) cerebral blood flow was varied by manipulating the arterial partial pressure of CO2 (Pa,CO2). LDF slightly overestimated CBF under conditions of haemorrhagic shock and haemodilution caused by controlled haemorrhage (paired t test, P

  15. Cerebral autoregulation dynamics in endurance-trained individuals

    NARCIS (Netherlands)

    M. Lind-Holst; J.D. Cotter; J.W. Helge; R. Boushel; H. Augustesen; J.J. van Lieshout; F.C. Pott

    2011-01-01

    Aerobic fitness may be associated with reduced orthostatic tolerance. To investigate whether trained individuals have less effective regulation of cerebral vascular resistance, we studied the middle cerebral artery (MCA) mean blood velocity (V(mean)) response to a sudden drop in mean arterial pressu

  16. The effect of S. pneumoniae bacteremia on cerebral blood flow autoregulation in rats

    DEFF Research Database (Denmark)

    Pedersen, Michael; Brandt, Christian T.; Knudsen, Gitte Moos

    2008-01-01

    In the present study, we studied the effect of bacteremia on cerebral blood flow (CBF) autoregulation in a rat model of pneumococcal bacteremia and meningitis. Anesthetized rats were divided into five groups (A to E) and inoculated with pneumococci intravenously and normal saline intracisternally...... (group A, N=10); saline intravenously and pneumococci intracisternally (group B, N=10); pneumococci intravenously and pneumococci intracisternally (group C, N=5); saline intravenously, antipneumococcal antibody intravenously (to prevent bacteremia), and pneumococci intracisternally (group D, N=10......bacteremia in rats triggers cerebral vasodilation, which right shifts...

  17. Salvinorin A administration after global cerebral hypoxia/ischemia preserves cerebrovascular autoregulation via kappa opioid receptor in piglets.

    Directory of Open Access Journals (Sweden)

    Zhenhong Wang

    Full Text Available BACKGROUND: Cerebral hypoxia/ischemia (HI is not uncommon during the perinatal period. If occurring, it can result in severe neurologic disabilities that persist throughout life. Salvinorin A, a non-opioid Kappa opioid receptors (KOR selective agonist, has the potential to address this devastating situation. We have demonstrated that salvinorin A administration before HI, preserves pial artery autoregulative function through both the KOR and extracellular signal-regulated kinases (ERK pathways. In the present study, we tested the hypothesis that administration of salvinorin A after HI could preserve cerebral autoregulation via KOR and ERK pathway. METHODOLOGY/PRINCIPAL FINDINGS: The response of the pial artery to hypercapnia, hypotension and isoproterenol were monitored before and 1 hour after HI in piglets equipped with a cranial window. Four groups of drug administration were performed after HI. The control group had DMSO (1 µl/kg, i.v. administrated immediately after HI. Two salvinorin A treated groups had salvinorin A (10 µg/kg, i.v. administrated 0 and 30 min after HI, respectively. The 4(th group had salvinorin A and the KOR antagonist norbinaltorphimine (Nor-BIN, 1 µM topical co-administrated 0 min after HI (n = 5. The dilation responses of the pial artery to hypercapnia and hypotension were impaired after global HI and were preserved with salvinorin A administration immediately or 30 min after HI. The preservation of autoregulation was abolished when nor-BIN was administered. Levels of phosphor-ERK(pERK/ERK in the cerebrospinal fluid (CSF were measured before and 1 hour after HI. After HI, the pERK/ERK levels significantly increased in both DMSO control group and salvinorin A and nor-BIN co-administration group. The elevated levels of pERK/ERK were not observed with salvinorin A only groups. CONCLUSIONS: Salvinorin A administration 0 and 30 min after HI preserves autoregulation of pial artery to hypercapnia and hypotension via

  18. Static cerebrovascular pressure autoregulation remains intact during deep hypothermia.

    Science.gov (United States)

    Goswami, Dheeraj; McLeod, Katherine; Leonard, Samantha; Kibler, Kathleen; Easley, Ronald Blaine; Fraser, Charles D; Andropoulos, Dean; Brady, Ken

    2017-09-01

    Clinical studies measuring cerebral blood flow in infants during deep hypothermia have demonstrated diminished cerebrovascular pressure autoregulation. The coexistence of hypotension in these cohorts confounds the conclusion that deep hypothermia impairs cerebrovascular pressure autoregulation. We sought to compare the lower limit of autoregulation and the static rate of autoregulation between normothermic and hypothermic piglets. Twenty anesthetized neonatal piglets (5-7 days old; 10 normothermic and 10 hypothermic to 20°C) had continuous measurements of cortical red cell flux using laser Doppler flowmetry, while hemorrhagic hypotension was induced without cardiopulmonary bypass. Lower limit of autoregulation was determined for each subject using piecewise regression and SRoR was determined above and below each lower limit of autoregulation as (%change cerebrovascular resistance/%change cerebral perfusion pressure). The estimated difference in lower limit of autoregulation was 1.4 mm Hg (lower in the hypothermic piglets; 95% C.I. -10 to 14 mm Hg; P=0.6). The median lower limit of autoregulation in the normothermic group was 39 mm Hg [IQR 38-51] vs 35 mm Hg [31-50] in the hypothermic group. Intact steady-state pressure autoregulation was defined as static rate of autoregulation >0.5 and was demonstrated in all normothermic subjects (static rate of autoregulation=0.72 [0.65-0.87]) and in 9/10 of the hypothermic subjects (static rate of autoregulation=0.65 [0.52-0.87]). This difference in static rate of autoregulation of 0.06 (95% C.I. -0.3 to 0.1) was not significant (P=0.4). Intact steady-state cerebrovascular pressure autoregulation is demonstrated in a swine model of profound hypothermia. Lower limit of autoregulation and static rate of autoregulation were similar in hypothermic and normothermic subjects. © 2017 John Wiley & Sons Ltd.

  19. Ventricular Volume Load Reveals the Mechanoelastic Impact of Communicating Hydrocephalus on Dynamic Cerebral Autoregulation.

    Directory of Open Access Journals (Sweden)

    Christina Haubrich

    Full Text Available Several studies have shown that the progression of communicating hydrocephalus is associated with diminished cerebral perfusion and microangiopathy. If communicating hydrocephalus similarly alters the cerebrospinal fluid circulation and cerebral blood flow, both may be related to intracranial mechanoelastic properties as, for instance, the volume pressure compliance. Twenty-three shunted patients with communicating hydrocephalus underwent intraventricular constant-flow infusion with Hartmann's solution. The monitoring included transcranial Doppler (TCD flow velocities (FV in the middle (MCA and posterior cerebral arteries (PCA, intracranial pressure (ICP, and systemic arterial blood pressure (ABP. The analysis covered cerebral perfusion pressure (CPP, the index of pressure-volume compensatory reserve (RAP, and phase shift angles between Mayer waves (3 to 9 cpm in ABP and MCA-FV or PCA-FV. Due to intraventricular infusion, the pressure-volume reserve was exhausted (RAP 0.84+/-0.1 and ICP was increased from baseline 11.5+/-5.6 to plateau levels of 20.7+/-6.4 mmHg. The ratio dRAP/dICP distinguished patients with large 0.1+/-0.01, medium 0.05+/-0.02, and small 0.02+/-0.01 intracranial volume compliances. Both M wave phase shift angles (r = 0.64; p<0.01 and CPP (r = 0.36; p<0.05 displayed a gradual decline with decreasing dRAP/dICP gradients. This study showed that in communicating hydrocephalus, CPP and dynamic cerebral autoregulation in particular, depend on the volume-pressure compliance. The results suggested that the alteration of mechanoelastic characteristics contributes to a reduced cerebral perfusion and a loss of autonomy of cerebral blood flow regulation. Results warrant a prospective TCD follow-up to verify whether the alteration of dynamic cerebral autoregulation may indicate a progression of communicating hydrocephalus.

  20. Dynamic cerebral autoregulation: different signal processing methods without influence on results and reproducibility.

    Science.gov (United States)

    Gommer, Erik D; Shijaku, Eri; Mess, Werner H; Reulen, Jos P H

    2010-12-01

    Cerebral autoregulation controls cerebral blood flow under changing cerebral perfusion pressure. Standards for measurement and analysis of dynamic cerebral autoregulation (dCA) are lacking. In this study, dCA reproducibility, quantified by intraclass correlation coefficient, is evaluated for different methodological approaches of transfer function analysis (TFA) and compared with multimodal pressure flow analysis (MMPF). dCA parameters were determined in 19 healthy volunteers during three 15-min lasting epochs of spontaneous breathing. Every spontaneous breathing epoch was followed by 5 min of paced breathing at 6 cycles/min. These six measurements were performed in both a morning and an afternoon session. Analysis compared raw data pre-processing by mean subtraction versus smoothness priors detrending. The estimation of spectral density was either performed by averaging of subsequent time windows or by smoothing the spectrum of the whole recording. No significant influence of pre-processing and spectral estimation on dCA parameters was found. Therefore, there seems to be no need to prescribe a specific signal-processing regime. Poor reproducibility of gain and phase was found for TFA as well as for MMPF. Based on reproducibility, no preference can be made for morning versus afternoon measurements, neither for spontaneous versus paced breathing. Finally, reproducibility results are not in favour of TFA or MMPF.

  1. Precision of coherence analysis to detect cerebral autoregulation by near-infrared spectroscopy in preterm infants

    Science.gov (United States)

    Hahn, Gitte Holst; Christensen, Karl Bang; Leung, Terence S.; Greisen, Gorm

    2010-05-01

    Coherence between spontaneous fluctuations in arterial blood pressure (ABP) and the cerebral near-infrared spectroscopy signal can detect cerebral autoregulation. Because reliable measurement depends on signals with high signal-to-noise ratio, we hypothesized that coherence is more precisely determined when fluctuations in ABP are large rather than small. Therefore, we investigated whether adjusting for variability in ABP (variabilityABP) improves precision. We examined the impact of variabilityABP within the power spectrum in each measurement and between repeated measurements in preterm infants. We also examined total monitoring time required to discriminate among infants with a simulation study. We studied 22 preterm infants (GA<30) yielding 215 10-min measurements. Surprisingly, adjusting for variabilityABP within the power spectrum did not improve the precision. However, adjusting for the variabilityABP among repeated measurements (i.e., weighting measurements with high variabilityABP in favor of those with low) improved the precision. The evidence of drift in individual infants was weak. Minimum monitoring time needed to discriminate among infants was 1.3-3.7 h. Coherence analysis in low frequencies (0.04-0.1 Hz) had higher precision and statistically more power than in very low frequencies (0.003-0.04 Hz). In conclusion, a reliable detection of cerebral autoregulation takes hours and the precision is improved by adjusting for variabilityABP between repeated measurements.

  2. What is the optimal anesthetic protocol for measurements of cerebral autoregulation in spontaneously breathing mice?

    Science.gov (United States)

    Wang, Zhenghui; Schuler, Beat; Vogel, Olga; Arras, Margarete; Vogel, Johannes

    2010-12-01

    Autoregulation, an important feature of the cerebral circulation, is affected in many diseases. Since genetically modified mice are a fundamental tool in biomedical research, including neuro(bio)logy also in this specie measurements of cerebral autoregulation (CA) are mandatory. However, this requires anesthesia that unfortunately significantly impacts cerebral perfusion and consequently might distort CA measurements directly or by altering arterial pCO(2). The latter can be avoided by artificial ventilation but requires several control measurements of blood gases, each consuming at least 100 μl of blood or 5% of a mouse's blood volume. To avoid such diagnostic hemorrhage, we systematically analyzed the effect of different common anesthetic protocols used for rodents in spontaneously breathing mice on CA measured with Laser speckle perfusion imaging. Halothane, Isoflurane and Pentobarbital abrogated CA and Ketamin/Xylazine as well as Chloralose had a moderate reproducibility. In contrast, the rather rarely used anesthetic Ethomidate applied in low doses combined with local anesthetics had the best reproducibility. Although with this anesthesia the lower CA limit was lower than with Ketamin/Xylazine and Chloralose as reported in the handful of papers so far dealing with CA in mice, we suggest Ethomidate as the anesthetic of choice for CA measurements in spontaneously breathing mice.

  3. Cerebral blood flow and autoregulation: current measurement techniques and prospects for noninvasive optical methods.

    Science.gov (United States)

    Fantini, Sergio; Sassaroli, Angelo; Tgavalekos, Kristen T; Kornbluth, Joshua

    2016-07-01

    Cerebral blood flow (CBF) and cerebral autoregulation (CA) are critically important to maintain proper brain perfusion and supply the brain with the necessary oxygen and energy substrates. Adequate brain perfusion is required to support normal brain function, to achieve successful aging, and to navigate acute and chronic medical conditions. We review the general principles of CBF measurements and the current techniques to measure CBF based on direct intravascular measurements, nuclear medicine, X-ray imaging, magnetic resonance imaging, ultrasound techniques, thermal diffusion, and optical methods. We also review techniques for arterial blood pressure measurements as well as theoretical and experimental methods for the assessment of CA, including recent approaches based on optical techniques. The assessment of cerebral perfusion in the clinical practice is also presented. The comprehensive description of principles, methods, and clinical requirements of CBF and CA measurements highlights the potentially important role that noninvasive optical methods can play in the assessment of neurovascular health. In fact, optical techniques have the ability to provide a noninvasive, quantitative, and continuous monitor of CBF and autoregulation.

  4. Monitoring of cerebral blood flow autoregulation in adults undergoing sevoflurane anesthesia: a prospective cohort study of two age groups.

    Science.gov (United States)

    Goettel, Nicolai; Patet, Camille; Rossi, Ariane; Burkhart, Christoph S; Czosnyka, Marek; Strebel, Stephan P; Steiner, Luzius A

    2016-06-01

    Autoregulation of blood flow is a key feature of the human cerebral vascular system to assure adequate oxygenation and metabolism of the brain under changing physiological conditions. The impact of advanced age and anesthesia on cerebral autoregulation remains unclear. The primary objective of this study was to determine the effect of sevoflurane anesthesia on cerebral autoregulation in two different age groups. This is a follow-up analysis of data acquired in a prospective observational cohort study. One hundred thirty-three patients aged 18-40 and ≥65 years scheduled for major noncardiac surgery under general anesthesia were included. Cerebral autoregulation indices, limits, and ranges were compared in young and elderly patient groups. Forty-nine patients (37 %) aged 18-40 years and 84 patients (63 %) aged ≥65 years were included in the study. Age-adjusted minimum alveolar concentrations of sevoflurane were 0.89 ± 0.07 in young and 0.99 ± 0.14 in older subjects (P blood pressure range of 13.8 ± 9.8 mmHg in young and 10.2 ± 8.6 mmHg in older patients (P = 0.079). The lower limit of autoregulation was 66 ± 12 mmHg and 73 ± 14 mmHg in young and older patients, respectively (P = 0.075). The association between sevoflurane concentrations and autoregulatory capacity was similar in both age groups. Our data suggests that the autoregulatory plateau is shortened in both young and older patients under sevoflurane anesthesia with approximately 1 MAC. Lower and upper limits of cerebral blood flow autoregulation, as well as the autoregulatory range, are not influenced by the age of anesthetized patients. Trial registration ClinicalTrials.gov (NCT00512200).

  5. The effects of poststroke captopril and losartan treatment on cerebral blood flow autoregulation in SHRsp with hemorrhagic stroke

    Science.gov (United States)

    Smeda, John S; Daneshtalab, Noriko

    2011-01-01

    The ability of captopril and losartan treatment to restore cerebral blood flow (CBF) autoregulation after intracerebral hemorrhagic stroke (HS) was assessed in Kyoto–Wistar stroke-prone hypertensive rats (SHRsp). Laser Doppler techniques assessed CBF autoregulation in the middle cerebral artery (MCA) perfusion domain and a pressure myograph was used to measure pressure-dependent constriction (PDC) in isolated MCAs before and after stroke and after 13, 33, and 63 days of poststroke captopril or losartan treatment. The treatments did not lower blood pressure (BP) and equally suppressed plasma aldosterone after HS. The HS development was associated with the loss of CBF autoregulation, high CBF, increased CBF conductance to elevations in BP, and the loss of PDC in the MCAs. Both treatments restored these functions to prestroke levels within 13 days. The PDC and CBF autoregulation subsequently deteriorated after 63 days of captopril treatment while being maintained at prestroke levels over all durations of losartan treatment. The SHRsp subjected to 35 days of poststroke losartan treatment exhibited less blood–brain barrier (BBB) disruption and brain herniation than captopril-treated SHRsp. The superior ability of losartan to restore CBF autoregulation and myogenic function may have contributed to the more effective attenuation of cerebral damage after HS. PMID:20648036

  6. Mimicking of cerebral autoregulation by flow-dependent cerebrovascular resistance: a feasibility study.

    Science.gov (United States)

    Kaufmann, Tim A S; Wong, Kai C; Schmitz-Rode, Thomas; Steinseifer, Ulrich

    2012-04-01

    Understanding circulatory autoregulation is essential for improving physiological control of rotary blood pumps and support conditions during cardiopulmonary bypass (CPB). Cerebral autoregulation (CAR), arguably the most critical, is the body's intrinsic ability to maintain sufficient cerebral blood flow (CBF) despite changes in aortic perfusion pressure. It is therefore imperative to include this mechanism into computational fluid dynamics (CFD), particle image velocimetry (PIV), or mock circulation loop (MCL) studies. Without such inclusions, potential losses of CBF are overestimated. In this study, a mathematical model to mimic CAR is implemented in a MCL- and PIV-validated CFD model. A three-dimensional model of the human vascular system was created from magnetic resonance imaging records. Numerical flow simulations were performed for physiological conditions and CPB. The inlet flow was varied between 4.5 and 6 L/min. Arterial outlets were modeled using vessel-specific, flow-dependent cerebrovascular resistances (CVRs), resulting in a variation of the pressure drop between 0 and 80mmHg. CBF is highly dependent on the level of CAR during CPB. By varying the CVR parameters up to the beginning of plateau phase, it can be regulated between 0 and 80% of physiological CBF. So while implementing autoregulation, CBF remains unchanged during a simulated native cardiac output of 5L/min or CPB support of 6L/min. Neglecting CAR, constant backflow from the brain occurs for some cannula positions. Using flow-dependent CVR, CBF returns to its baseline at a rate of recovery of 0.25s. Results demonstrate that modeling of CAR by flow-dependent CVR delivers feasible results. The presented method can be used to optimize physiological control of assist devices dependent upon different levels of CAR representing different patients.

  7. Assessment of cerebral blood flow autoregulation (CBF AR) with rheoencephalography (REG): studies in animals

    Science.gov (United States)

    Popovic, Djordje; Bodo, Michael; Pearce, Frederick; van Albert, Stephen; Garcia, Alison; Settle, Tim; Armonda, Rocco

    2013-04-01

    The ability of cerebral vasculature to regulate cerebral blood flow (CBF) in the face of changes in arterial blood pressure (SAP) or intracranial pressure (ICP) is an important guard against secondary ischemia in acute brain injuries, and official guidelines recommend that therapeutic decisions be guided by continuous monitoring of CBF autoregulation (AR). The common method for CBF AR monitoring, which rests on real-time derivation of the correlation coefficient (PRx) between slow oscillations in SAP and ICP is, however, rarely used in clinical practice because it requires invasive ICP measurements. This study investigated whether the correlation coefficient between SAP and the pulsatile component of the non-invasive transcranial bioimpedance signal (rheoencephalography, REG) could be used to assess the state and lower limit of CBF AR. The results from pigs and rhesus macaques affirm the utility of REG; however, additional animal and clinical studies are warranted to assess selectivity of automatic REG-based evaluation of CBF AR.

  8. Cardiovascular and Postural Control Interactions during Hypergravity: Effects on Cerebral Autoregulation in Males and Females

    Science.gov (United States)

    Goswami, Nandu; Blaber, Andrew; Bareille, Marie-Pierre; Beck, Arnaud; Avan, Paul; Bruner, Michelle; Hinghofer-Szalkay, Helmut

    2012-07-01

    Orthostatic intolerance remains a problem upon return to Earth from the microgravity environment of spaceflight. A variety of conditions including hypovolemia, cerebral vasoconstriction, cerebral or peripheral vascular disease, or cardiac arrhythmias may result in syncope if the person remains upright. Current research indicates that there is a greater dependence on visual and somatosensory information at the beginning of space flight with a decreased otolith gain during prolonged space flight (Herault et al., 2002). The goal of the research is to further our understanding of the fundamental adaptive homeostatic mechanisms involved in gravity related changes in cardiovascular and postural function. Cardiovascular, cerebrovascular, and postural sensory motor control systems in male and female participants before, during, and after exposure to graded levels of hyper-G were investigated. Hypotheses: 1) Activation of skeletal muscle pump will be directly related to the degree of orthostatic stress. 2) Simultaneous measurement of heart rate, blood pressure and postural sway will predict cardio-postural stability. Blood pressure and heart rate (means and variability), postural sway, center of pressure (COP), baroreflex function, calf blood flow, middle cerebral artery blood flow, non-invasive intracranial pressure measurements, and two-breath CO2 were measured. Results from the study will be used to provide an integrated insight into mechanisms of cardio-postural control and cerebral autoregulation, which are important aspects of human health in flights to Moon, Mars and distant planets.

  9. How measurement artifacts affect cerebral autoregulation outcomes: A technical note on transfer function analysis.

    Science.gov (United States)

    Meel-van den Abeelen, Aisha S S; de Jong, Daan L K; Lagro, Joep; Panerai, Ronney B; Claassen, Jurgen A H R

    2016-05-01

    Cerebral autoregulation (CA) is the mechanism that aims to maintain adequate cerebral perfusion during changes in blood pressure (BP). Transfer function analysis (TFA), the most reported method in literature to quantify CA, shows large between-study variability in outcomes. The aim of this study is to investigate the role of measurement artifacts in this variation. Specifically, the role of distortion in the BP and/or CBFV measurementon TFA outcomes was investigated. The influence of three types of artifacts on TFA outcomes was studied: loss of signal, motion artifacts, and baseline drifts. TFA metrics of signals without the simulated artifacts were compared with those of signals with artifacts. TFA outcomes scattered highly when more than 10% of BP signal or over 8% of the CBFV signal was lost, or when measurements contained one or more artifacts resulting from head movement. Furthermore, baseline drift affected interpretation of TFA outcomes when the power in the BP signal was 5 times the power in the LF band. In conclusion, loss of signal in BP and loss in CBFV, affects interpretation of TFA outcomes. Therefore, it is vital to validate signal quality to the defined standards before interpreting TFA outcomes.

  10. Altered free radical metabolism in acute mountain sickness: implications for dynamic cerebral autoregulation and blood-brain barrier function

    DEFF Research Database (Denmark)

    Bailey, D M; Evans, K A; James, P E

    2008-01-01

    (2)) and following 6 h passive exposure to hypoxia (12% O(2)). Blood flow velocity in the middle cerebral artery (MCAv) and mean arterial blood pressure (MAP) were measured for determination of CA following calculation of transfer function analysis and rate of regulation (RoR). Nine subjects......We tested the hypothesis that dynamic cerebral autoregulation (CA) and blood-brain barrier (BBB) function would be compromised in acute mountain sickness (AMS) subsequent to a hypoxia-mediated alteration in systemic free radical metabolism. Eighteen male lowlanders were examined in normoxia (21% O...

  11. Dynamic cerebral autoregulation to induced blood pressure changes in human experimental and clinical sepsis

    DEFF Research Database (Denmark)

    Berg, Ronan M G; Plovsing, Ronni R; Bailey, Damian M

    2016-01-01

    (Pvolunteers at baseline; Pvolunteers after LPS). The corresponding RoR values increased from 0·46 (0·31-0·49) s(-1) at baseline to 0·58 (0·36-0·74) s(-1) after LPS (Pvolunteers, whereas they were similar to values observed in patients [0·43 (0·36-0·52) s...... shock. In this study, we hypothesized that this pattern of response would be identical during induced changes in blood pressure. Dynamic cerebral autoregulation was assessed in nine healthy volunteers and six septic patients. The healthy volunteers underwent a 4-h intravenous infusion of LPS (total dose......R). This was performed before and after LPS infusion in healthy volunteers, and within 72 h following clinical diagnosis of sepsis in patients. In healthy volunteers, thigh-cuff deflation caused a MAP reduction of 16 (13-20) % at baseline and 18 (16-20) % after LPS, while the MAP reduction was 12 (11-13) % in patients...

  12. Zinc-Finger Nuclease Knockout of Dual-Specificity Protein Phosphatase-5 Enhances the Myogenic Response and Autoregulation of Cerebral Blood Flow in FHH.1BN Rats

    Science.gov (United States)

    Fan, Fan; Geurts, Aron M.; Pabbidi, Mallikarjuna R.; Smith, Stanley V.; Harder, David R.; Jacob, Howard; Roman, Richard J.

    2014-01-01

    We recently reported that the myogenic responses of the renal afferent arteriole (Af-Art) and middle cerebral artery (MCA) and autoregulation of renal and cerebral blood flow (RBF and CBF) were impaired in Fawn Hooded hypertensive (FHH) rats and were restored in a FHH.1BN congenic strain in which a small segment of chromosome 1 from the Brown Norway (BN) containing 15 genes including dual-specificity protein phosphatase-5 (Dusp5) were transferred into the FHH genetic background. We identified 4 single nucleotide polymorphisms in the Dusp5 gene in FHH as compared with BN rats, two of which altered CpG sites and another that caused a G155R mutation. To determine whether Dusp5 contributes to the impaired myogenic response in FHH rats, we created a Dusp5 knockout (KO) rat in the FHH.1BN genetic background using a zinc-finger nuclease that introduced an 11 bp frame-shift deletion and a premature stop codon at AA121. The expression of Dusp5 was decreased and the levels of its substrates, phosphorylated ERK1/2 (p-ERK1/2), were enhanced in the KO rats. The diameter of the MCA decreased to a greater extent in Dusp5 KO rats than in FHH.1BN and FHH rats when the perfusion pressure was increased from 40 to 140 mmHg. CBF increased markedly in FHH rats when MAP was increased from 100 to 160 mmHg, and CBF was better autoregulated in the Dusp5 KO and FHH.1BN rats. The expression of Dusp5 was higher at the mRNA level but not at the protein level and the levels of p-ERK1/2 and p-PKC were lower in cerebral microvessels and brain tissue isolated from FHH than in FHH.1BN rats. These results indicate that Dusp5 modulates myogenic reactivity in the cerebral circulation and support the view that a mutation in Dusp5 may enhance Dusp5 activity and contribute to the impaired myogenic response in FHH rats. PMID:25397684

  13. Zinc-finger nuclease knockout of dual-specificity protein phosphatase-5 enhances the myogenic response and autoregulation of cerebral blood flow in FHH.1BN rats.

    Directory of Open Access Journals (Sweden)

    Fan Fan

    Full Text Available We recently reported that the myogenic responses of the renal afferent arteriole (Af-Art and middle cerebral artery (MCA and autoregulation of renal and cerebral blood flow (RBF and CBF were impaired in Fawn Hooded hypertensive (FHH rats and were restored in a FHH.1BN congenic strain in which a small segment of chromosome 1 from the Brown Norway (BN containing 15 genes including dual-specificity protein phosphatase-5 (Dusp5 were transferred into the FHH genetic background. We identified 4 single nucleotide polymorphisms in the Dusp5 gene in FHH as compared with BN rats, two of which altered CpG sites and another that caused a G155R mutation. To determine whether Dusp5 contributes to the impaired myogenic response in FHH rats, we created a Dusp5 knockout (KO rat in the FHH.1BN genetic background using a zinc-finger nuclease that introduced an 11 bp frame-shift deletion and a premature stop codon at AA121. The expression of Dusp5 was decreased and the levels of its substrates, phosphorylated ERK1/2 (p-ERK1/2, were enhanced in the KO rats. The diameter of the MCA decreased to a greater extent in Dusp5 KO rats than in FHH.1BN and FHH rats when the perfusion pressure was increased from 40 to 140 mmHg. CBF increased markedly in FHH rats when MAP was increased from 100 to 160 mmHg, and CBF was better autoregulated in the Dusp5 KO and FHH.1BN rats. The expression of Dusp5 was higher at the mRNA level but not at the protein level and the levels of p-ERK1/2 and p-PKC were lower in cerebral microvessels and brain tissue isolated from FHH than in FHH.1BN rats. These results indicate that Dusp5 modulates myogenic reactivity in the cerebral circulation and support the view that a mutation in Dusp5 may enhance Dusp5 activity and contribute to the impaired myogenic response in FHH rats.

  14. Identifying stable phase coupling associated with cerebral autoregulation using the synchrosqueezed cross-wavelet transform and low oscillation morlet wavelets.

    Science.gov (United States)

    Addison, Paul S

    2015-01-01

    A novel method of identifying stable phase coupling behavior of two signals within the wavelet transform time-frequency plane is presented. The technique employs the cross-wavelet transform to provide a map of phase coupling followed by synchrosqueezing to collect the stable phase regime information. The resulting synchrosqueezed cross-wavelet transform method (Synchro-CrWT) is illustrated using a synthetic signal and then applied to the analysis of the relationship between biosignals used in the analysis of cerebral autoregulation function.

  15. Impaired autoregulation of the glomerular filtration rate in patients with nondiabetic nephropathies

    DEFF Research Database (Denmark)

    Christensen, P K; Hommel, E E; Clausen, P

    1999-01-01

    BACKGROUND: The ability of the kidney to maintain constancy of the glomerular filtration rate (GFR) over a wide range of renal perfusion pressures is termed autoregulation. Defective autoregulation of GFR has been demonstrated in diabetic nephropathy. Whether this is also the case in patients...

  16. Cerebral vascular effects of hypovolemia and dopamine infusions

    DEFF Research Database (Denmark)

    Holst Hahn, Gitte; Heiring, Christian; Pryds, Ole

    2012-01-01

    Despite widespread use, effects of volume boluses and dopamine in hypotensive newborn infants remain controversial. We aimed to elucidate if hypovolemia alone impairs cerebral autoregulation (CA) and if dopamine affects cerebral vasculature.......Despite widespread use, effects of volume boluses and dopamine in hypotensive newborn infants remain controversial. We aimed to elucidate if hypovolemia alone impairs cerebral autoregulation (CA) and if dopamine affects cerebral vasculature....

  17. Impaired autoregulation of renal blood flow in the fawn-hooded rat

    NARCIS (Netherlands)

    R.P.E. van Dokkum (Richard); M. Alonso-Galicia; A.P. Provoost (Abraham); H.J. Jacob (Howard); R.J. Roman

    1999-01-01

    textabstractThe responses to changes in renal perfusion pressure (RPP) were compared in 12-wk-old fawn-hooded hypertensive (FHH), fawn-hooded low blood pressure (FHL), and August Copenhagen Irish (ACI) rats to determine whether autoregulation of renal blood flow (RBF) i

  18. Cerebral autoregulation in the preterm newborn using near-infrared spectroscopy: a comparison of time-domain and frequency-domain analyses

    Science.gov (United States)

    Eriksen, Vibeke R.; Hahn, Gitte H.; Greisen, Gorm

    2015-03-01

    The aim was to compare two conventional methods used to describe cerebral autoregulation (CA): frequency-domain analysis and time-domain analysis. We measured cerebral oxygenation (as a surrogate for cerebral blood flow) and mean arterial blood pressure (MAP) in 60 preterm infants. In the frequency domain, outcome variables were coherence and gain, whereas the cerebral oximetry index (COx) and the regression coefficient were the outcome variables in the time domain. Correlation between coherence and COx was poor. The disagreement between the two methods was due to the MAP and cerebral oxygenation signals being in counterphase in three cases. High gain and high coherence may arise spuriously when cerebral oxygenation decreases as MAP increases; hence, time-domain analysis appears to be a more robust-and simpler-method to describe CA.

  19. 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....

  20. Model-based physiomarkers of cerebral hemodynamics in patients with mild cognitive impairment.

    Science.gov (United States)

    Marmarelis, V Z; Shin, D C; Orme, M E; Zhang, R

    2014-05-01

    In our previous studies, we have introduced model-based "functional biomarkers" or "physiomarkers" of cerebral hemodynamics that hold promise for improved diagnosis of early-stage Alzheimer's disease (AD). The advocated methodology utilizes subject-specific data-based dynamic nonlinear models of cerebral hemodynamics to compute indices (serving as possible diagnostic physiomarkers) that quantify the state of cerebral blood flow autoregulation to pressure-changes (CFAP) and cerebral CO2 vasomotor reactivity (CVMR) in each subject. The model is estimated from beat-to-beat measurements of mean arterial blood pressure, mean cerebral blood flow velocity and end-tidal CO2, which can be made reliably and non-invasively under resting conditions. In a previous study, it was found that a CVMR index quantifying the impairment in CO2 vasomotor reactivity correlates with clinical indications of early AD, offering the prospect of a potentially useful diagnostic tool. In this paper, we explore the use of the same model-based indices for patients with amnestic Mild Cognitive Impairment (MCI), a preclinical stage of AD, relative to a control subjects and clinical cognitive assessments. It was found that the model-based CVMR values were lower for MCI patients relative to the control subjects.

  1. Dynamic cerebral autoregulatory capacity is affected early in Type 2 diabetes

    DEFF Research Database (Denmark)

    Kim, Y.S.; Immink, R.V.; Stok, W.J.

    2008-01-01

    Type 2 diabetes is associated with an increased risk of endothelial dysfunction and microvascular complications with impaired autoregulation of tissue perfusion. Both microvascular disease and cardiovascular autonomic neuropathy may affect cerebral autoregulation. In the present study, we tested...... the hypothesis that, in the absence of cardiovascular autonomic neuropathy, cerebral autoregulation is impaired in subjects with DM+ (Type 2 diabetes with microvascular complications) but intact in subjects with DM- (Type 2 diabetes without microvascular complications). Dynamic cerebral autoregulation......, -15+/-6% in subjects with DM- and -15+/-7% in subjects with DM+). HbA(1c) (glycated haemoglobin) and the duration of diabetes, but not blood pressure, were determinants of transfer function phase. In conclusion, dysfunction of dynamic cerebral autoregulation in subjects with Type 2 diabetes appears...

  2. Impaired autoregulation of glomerular filtration rate in type 1 (insulin-dependent) diabetic patients with nephropathy

    DEFF Research Database (Denmark)

    Parving, H H; Kastrup, Helge; Smidt, U M;

    1984-01-01

    served as controls. Renal function was assessed by glomerular filtration rate (single bolus 51Cr-EDTA technique) and urinary albumin excretion rate (radial immunodiffusion). The study was performed twice within 2 weeks, with the subjects receiving an intravenous injection of either clonidine (225...... arterial blood pressure in all three groups (16-18 mmHg). While glomerular filtration rate and urinary albumin excretion rate remained unchanged in both control groups after clonidine injection, glomerular filtration rate diminished from 78 to 71 ml/min per 1.73 m2 (p les than 0.01), and urinary albumin...... excretion declined from 1707 to 938 micrograms/min (p less than 0.01) in the patients with diabetic nephropathy. Our results suggest that an intrinsic vascular (arteriolar) mechanism underlying the normal autoregulation of glomerular filtration rate, i.e. the relative constancy of glomerular filtration rate...

  3. Impaired autoregulation of glomerular filtration rate in type 1 (insulin-dependent) diabetic patients with nephropathy

    DEFF Research Database (Denmark)

    Parving, H H; Kastrup, Helge; Smidt, U M

    1984-01-01

    The effect of acute lowering of arterial blood pressure upon kidney function in nephropathy was studied in 13 patients with long-term Type 1 (insulin-dependent) diabetes. Ten normal subjects (six normotensive and four hypertensive) and five short-term Type 1 diabetic patients without nephropathy...... micrograms) or saline (0.154 mmol/l). The arterial blood pressure was similar in the diabetic patients with nephropathy (mean 136 +/- 11 divided by 88 +/- mmHg) and in the non-diabetic control subjects (mean 140 +/- 25 divided by 92 +/- 15 mmHg). The clonidine injection induced similar reductions in mean...... excretion declined from 1707 to 938 micrograms/min (p less than 0.01) in the patients with diabetic nephropathy. Our results suggest that an intrinsic vascular (arteriolar) mechanism underlying the normal autoregulation of glomerular filtration rate, i.e. the relative constancy of glomerular filtration rate...

  4. Phase Synchronization of Pressure-Flow Fluctuations: A measure of cerebral autoregulation dynamics

    CERN Document Server

    Chen, Z; Ivanov, P C; Novák, V; Stanley, H E

    2006-01-01

    We employ a synchronization method to investigate the relationship between the blood flow velocities (BFV) in the middle cerebral arteries (MCA) and beat-to-beat blood pressure (BP) recorded from a finger in healthy and post-stroke subjects during four different physiologic conditions: supine, head-up tilt, hyperventilation and CO$_2$ rebreathing in upright position. To evaluate whether instantaneous BP changes are synchronized with changes in the BFV, we compare dynamical patterns in the instantaneous phases of these signals, obtained from the Hilbert transform, as a function of time. We find that in post-stroke subjects the instantaneous phase increments of BP and BFV exhibit well pronounced patterns that remain stable in time for all four physiologic conditions, while in healthy subjects these patterns are different, less pronounced and more variable. Further, we show that the instantaneous phase increments of BP and BFV are cross-correlated even within a single heartbeat cycle. The maximum correlation str...

  5. Effects of Sustained Low-Level Elevations of Carbon Dioxide on Cerebral Blood Flow and Autoregulation of the Intracerebral Arteries in Humans

    Science.gov (United States)

    Sliwka, U.; Krasney, J. A.; Simon, S. G.; Schmidt, P.

    1996-01-01

    Cerebral blood flow velocity (CBFv) was measured by insonating the middle cerebral arteries of 4 subjects using a 2 Mhz transcranial Doppler. Ambient CO2 was elevated to 0.7% for 23 days in the first study and to 1.2% for 23 days in the same subjects in the second study. By non-parametric testing CBFv was elevated significantly by +35% above pre-exposure levels during the first 1-3 days at both exposure levels after which CBFv progressively readjusted to pre-exposure levels. Despite similar CBFv responses, headache was only reported during the initial phase of exposure to 1.2% CO2. Vascular reactivity to CO2 assessed by rebreathing showed a similar pattern with the CBFv increases early in the exposures being greater than those elicited later. An increase in metabolic rate of the visual cortex was evoked by having the subjects open and close their eyes during a visual stimulus. Evoked CBFv responses measured in the posterior cerebral artery were also elevated in the first 1-3 days of both studies returning to pre-exposure levels as hypercapnia continued. Cerebral vascular autoregulation assessed by raising head pressure during 10 deg head-down tilt both during the low-level exposures and during rebreathing was unaltered. There were no changes in the retinal microcirculation during serial fundoscopy studies. The time-dependent changes in CO2 vascular reactivity might be due either to retention of bicarbonate in brain extracellular fluid or to progressive increases in ventilation, or both. Cerebral vascular autoregulation appears preserved during chronic exposure to these levels of ambient CO2.

  6. Age-dependent NOC/oFQ contribution to impaired hypotensive cerebral hemodynamics after brain injury.

    Science.gov (United States)

    Armstead, William M

    2002-10-01

    Previous studies have observed that the newly described opioid, nociceptin/orphanin FQ (NOC/oFQ), contributed to age dependent reductions in cerebral blood flow (CBF) and pial artery diameter after fluid percussion brain injury (FPI). Unrelated studies have noted a similar age dependency in impaired hypotensive cerebral autoregulation after FPI. This study was designed to compare the role of NOC/oFQ in impaired hypotensive cerebral autoregulation after FPI in newborn and juvenile pigs equipped with a closed cranial window. Ten minutes of hemorrhagic hypotension (10-15 mL blood/kg) decreased mean arterial blood pressure uniformly in both groups ( approximately 44%). In the newborn, hypotensive pial artery dilation was blunted within 1 h of FPI but partially protected by pretreatment with the NOC/oFQ antagonist, [F/G] NOC/oFQ (1-13) NH(2) (1 mg/kg, i.v.) (34 +/- 1 vs. 8 +/- 1 vs. 20 +/- 2% for sham control, FPI, and FPI-[F/G] NOC/oFQ (1-13) NH(2), respectively). CBF was reduced during normotension by FPI, further reduced by hypotension, but both were partially protected by this antagonist in the newborn (63 +/- 4, 34 +/- 2, and 20 +/- 2 vs. 65 +/- 4, 47 +/- 2, and 29 +/- 2 mL/min.100 g for normotension, normotension-FPI and hypotension-FPI in the absence and presence of [F/G] NOC/oFQ (1-13) NH(2), respectively). In contrast, blunted hypotensive pial artery dilation was protected significantly less by this NOC/oFQ antagonist in the juvenile (32 +/- 2 vs. 7 +/- 2 vs. 13 +/- 2% for sham control, FPI and FPI-NOC/oFQ antagonist, respectively). Similarly, [F/G] NOC/oFQ (1-13) NH(2) had less protective effect on normotensive and hypotensive CBF values post FPI in the juvenile. These data indicate that NOC/oFQ contributes to impaired hypotensive cerebral hemodynamics following brain injury in an age-dependent manner.

  7. High-NaCl intake impairs dynamic autoregulation of renal blood flow in ANG II-infused rats

    DEFF Research Database (Denmark)

    Saeed, Aso; Dibona, Gerald F; Marcussen, Niels

    2010-01-01

    The aim of this study was to investigate dynamic autoregulation of renal blood flow (RBF) in ANG II-infused rats and the influence of high-NaCl intake. Sprague-Dawley rats received ANG II (250 ng·kg(-1)·min(-1) sc) or saline vehicle (sham) for 14 days after which acute renal clearance experiments...

  8. High-NaCl diet impairs dynamic renal blood flow autoregulation in rats with adenine-induced chronic renal failure

    DEFF Research Database (Denmark)

    Saeed, Aso; DiBona, Gerald F; Grimberg, Elisabeth

    2014-01-01

    This study examined the effects of 2 wk of high-NaCl diet on kidney function and dynamic renal blood flow autoregulation (RBFA) in rats with adenine-induced chronic renal failure (ACRF). Male Sprague-Dawley rats received either chow containing adenine or were pair-fed an identical diet without ad...

  9. T2’-Imaging to Assess Cerebral Oxygen Extraction Fraction in Carotid Occlusive Disease: Influence of Cerebral Autoregulation and Cerebral Blood Volume

    Science.gov (United States)

    Deichmann, Ralf; Pfeilschifter, Waltraud; Hattingen, Elke; Singer, Oliver C.; Wagner, Marlies

    2016-01-01

    Purpose Quantitative T2'-mapping detects regional changes of the relation of oxygenated and deoxygenated hemoglobin (Hb) by using their different magnetic properties in gradient echo imaging and might therefore be a surrogate marker of increased oxygen extraction fraction (OEF) in cerebral hypoperfusion. Since elevations of cerebral blood volume (CBV) with consecutive accumulation of Hb might also increase the fraction of deoxygenated Hb and, through this, decrease the T2’-values in these patients we evaluated the relationship between T2’-values and CBV in patients with unilateral high-grade large-artery stenosis. Materials and Methods Data from 16 patients (13 male, 3 female; mean age 53 years) with unilateral symptomatic or asymptomatic high-grade internal carotid artery (ICA) or middle cerebral artery (MCA) stenosis/occlusion were analyzed. MRI included perfusion-weighted imaging and high-resolution T2’-mapping. Representative relative (r)CBV-values were analyzed in areas of decreased T2’ with different degrees of perfusion delay and compared to corresponding contralateral areas. Results No significant elevations in cerebral rCBV were detected within areas with significantly decreased T2’-values. In contrast, rCBV was significantly decreased (pperfusion delay and decreased T2’. Furthermore, no significant correlation between T2’- and rCBV-values was found. Conclusions rCBV is not significantly increased in areas of decreased T2’ and in areas of restricted perfusion in patients with unilateral high-grade stenosis. Therefore, T2’ should only be influenced by changes of oxygen metabolism, regarding our patient collective especially by an increase of the OEF. T2’-mapping is suitable to detect altered oxygen consumption in chronic cerebrovascular disease. PMID:27560515

  10. Attentional and executive impairments in children with spastic cerebral palsy

    DEFF Research Database (Denmark)

    Bottcher, Louise; Flachs, Esben Meulengracht; Uldall, Peter

    2010-01-01

    Children with cerebral palsy (CP) are reported to have learning and social problems. The aim of the present study was to examine whether children with CP have impairments in attention or executive function.......Children with cerebral palsy (CP) are reported to have learning and social problems. The aim of the present study was to examine whether children with CP have impairments in attention or executive function....

  11. Defective cerebrovascular autoregulation after carotid endarterectomy

    DEFF Research Database (Denmark)

    Jørgensen, L G; Schroeder, T V

    1993-01-01

    Correction of high grade carotid artery stenosis may result in cerebral hyperperfusion because of defective vascular autoregulation. Thus, transcranial Doppler was used to determine mean arterial flow velocity (Vmean) of the middle cerebral artery in 95 patients before and after carotid endartere...

  12. Identifying and characterising cerebral visual impairment in children: a review.

    Science.gov (United States)

    Philip, Swetha Sara; Dutton, Gordon N

    2014-05-01

    Cerebral visual impairment (CVI) comprises visual malfunction due to retro-chiasmal visual and visual association pathway pathology. This can be isolated or accompany anterior visual pathway dysfunction. It is a major cause of low vision in children in the developed and developing world due to increasing survival in paediatric and neonatal care. CVI can present in many combinations and degrees. There are multiple causes and it is common in children with cerebral palsy. CVI can be identified easily, if a structured approach to history-taking is employed. This review describes the features of CVI and describes practical management strategies aimed at helping affected children. A literature review was undertaken using 'Medline' and 'Pubmed'. Search terms included cerebral visual impairment, cortical visual impairment, dorsal stream dysfunction and visual function in cerebral palsy.

  13. Impaired cerebral autoregulation during head up tilt in patients with severe brain injury

    DEFF Research Database (Denmark)

    Riberholt, Christian Gunge; Olesen, Niels Damkjær; Thing, Mira

    2016-01-01

    acquired brain injury and a low level of consciousness. Fourteen patients with severe acquired brain injury and orthostatic intolerance and fifteen healthy volunteers were enrolled. Blood pressure was evaluated by pulse contour analysis, heart rate and RR-intervals were determined by electrocardiography...

  14. Cerebral autoregulation and flow/metabolism coupling during cardiopulmonary bypass: the influence of PaCO/sub 2/

    Energy Technology Data Exchange (ETDEWEB)

    Murkin, J.M.; Farrar, J.K.; Tweed, W.A.; McKenzie, F.N.; Guiraudon, G.

    1987-09-01

    Measurement of /sup 133/Xe clearance and effluent cerebral venous blood sampling were used in 38 patients to determine the effects of cardiopulmonary bypass, and of maintaining temperature corrected or noncorrected PaCO/sub 2/ at 40 mm Hg on regulation of cerebral blood flow (CBF) and flow/metabolism coupling. After induction of anesthesia with diazepam and fentanyl, mean CBF was 25 ml X 100 g-1 X min-1 and cerebral oxygen consumption, 1.67 ml X 100 g-1 X min-1. Cerebral oxygen consumption during nonpulsatile cardiopulmonary bypass at 26 degrees C was reduced to 0.42 ml X 100 g-1 X min-1 in both groups. CBF was reduced to 14-15 ml X 100 g-1 X min-1 in the non-temperature-corrected group (n = 21), was independent of cerebral perfusion pressure over the range of 20-100 mm Hg, but correlated with cerebral oxygen consumption. In the temperature-corrected group (n = 17), CBF varied from 22 to 32 ml X 100 g-1 X min-1, and flow/metabolism coupling was not maintained (i.e., CBF and cerebral oxygen consumption varied independently). However, variation in CBF correlated significantly with cerebral perfusion pressure over the pressure range of 15-95 mm Hg. This study demonstrates a profound reduction in cerebral oxygen consumption during hypothermic nonpulsatile cardiopulmonary bypass. When a non-temperature-corrected PaCO/sub 2/ of approximately 40 mm Hg was maintained, CBF was lower, and analysis of pooled data suggested that CBF regulation was better preserved, i.e., CBF was independent of pressure changes and dependent upon cerebral oxygen consumption.

  15. Development and face validity of a cerebral visual impairment motor questionnaire for children with cerebral palsy

    NARCIS (Netherlands)

    Salavati, M.; Waninge, A.; Rameckers, E. A. A.; van der Steen, J.; Krijnen, W. P.; van der Schans, C. P.; Steenbergen, B.

    2017-01-01

    Aim The objectives of this study were (i) to develop two cerebral visual impairment motor questionnaires (CVI-MQ's) for children with cerebral palsy (CP): one for children with Gross Motor Function Classification System (GMFCS) levels I, II and III and one for children with GMFCS levels IV and V; (i

  16. Impaired Voluntary Movement Control and Its Rehabilitation in Cerebral Palsy.

    Science.gov (United States)

    Gordon, Andrew M

    2016-01-01

    Cerebral palsy is caused by early damage to the developing brain, as the most common pediatric neurological disorder. Hemiplegia (unilateral spastic cerebral palsy) is the most common subtype, and the resulting impairments, lateralized to one body side, especially affect the upper extremity, limiting daily function. This chapter first describes the pathophysiology and mechanisms underlying impaired upper extremity control of cerebral palsy. It will be shown that the severity of impaired hand function closely relates to the integrity of the corticospinal tract innervating the affected hand. It will also shown that the developing corticospinal tract can reorganize its connectivity depending on the timing and location of CNS injury, which also has implications for the severity of hand impairments and rehabilitation. The mechanisms underlying impaired motor function will be highlighted, including deficits in movement execution and planning and sensorimotor integration. It will be shown that despite having unimanual hand impairments, bimanual movement control deficits and mirror movements also impact function. Evidence for motor learning-based therapies including Constraint-Induced Movement Therapy and Bimanual Training, and the possible pathophysiological predictors of treatment outcome and plasticity will be described. Finally, future directions for rehabilitations will be presented.

  17. Does cerebral large-artery disease contribute to cognitive impairment?

    Directory of Open Access Journals (Sweden)

    Satoshi Kimura

    2017-09-01

    Conclusion: Impaired cognition was observed in some of the non-demented patients with CLAD. Older age, drinking habit, severe PVH and decreased cerebral perfusion contributed to their poor cognitive performance. Strict treatment of atherosclerosis and intervention for CLAD might be necessary to prevent cognitive decline in these patients.

  18. Limb distribution, motor impairment, and functional classification of cerebral palsy

    NARCIS (Netherlands)

    J.A. Gorter; P.L. Rosenbaum

    2004-01-01

    This study explored the relationships between the Gross Motor Function Classification System (GMFCS), limb distribution, and type of motor impairment. Data used were collected in the Ontario Motor Growth study, a longitudinal cohort study with a population-based sample of children with cerebral pals

  19. Correlation between cerebral hemodynamic and perfusion pressure changes in non-human primates

    Science.gov (United States)

    Ruesch, A.; Smith, M. A.; Wollstein, G.; Sigal, I. A.; Nelson, S.; Kainerstorfer, J. M.

    2017-02-01

    The mechanism that maintains a stable blood flow in the brain despite changes in cerebral perfusion pressure (CPP), and therefore guaranties a constant supply of oxygen and nutrients to the neurons, is known as cerebral auto-regulation (CA). In a certain range of CPP, blood flow is mediated by a vasomotor adjustment in vascular resistance through dilation of blood vessels. CA is known to be impaired in diseases like traumatic brain injury, Parkinson's disease, stroke, hydrocephalus and others. If CA is impaired, blood flow and pressure changes are coupled and thee oxygen supply might be unstable. Lassen's blood flow auto-regulation curve describes this mechanism, where a plateau of stable blood flow in a specific range of CPP corresponds to intact auto-regulation. Knowing the limits of this plateau and maintaining CPP within these limits can improve patient outcome. Since CPP is influenced by both intracranial pressure and arterial blood pressure, long term changes in either can lead to auto-regulation impairment. Non-invasive methods for monitoring blood flow auto-regulation are therefore needed. We propose too use Near infrared spectroscopy (NIRS) too fill this need. NIRS is an optical technique, which measures microvascular changes in cerebral hemoglobin concentration. We performed experiments on non-human primates during exsanguination to demonstrate that thee limits of blood flow auto-regulation can be accessed with NIRS.

  20. Cerebral versus Ocular Visual Impairment: The Impact on Developmental Neuroplasticity.

    Science.gov (United States)

    Martín, Maria B C; Santos-Lozano, Alejandro; Martín-Hernández, Juan; López-Miguel, Alberto; Maldonado, Miguel; Baladrón, Carlos; Bauer, Corinna M; Merabet, Lotfi B

    2016-01-01

    Cortical/cerebral visual impairment (CVI) is clinically defined as significant visual dysfunction caused by injury to visual pathways and structures occurring during early perinatal development. Depending on the location and extent of damage, children with CVI often present with a myriad of visual deficits including decreased visual acuity and impaired visual field function. Most striking, however, are impairments in visual processing and attention which have a significant impact on learning, development, and independence. Within the educational arena, current evidence suggests that strategies designed for individuals with ocular visual impairment are not effective in the case of CVI. We propose that this variance may be related to differences in compensatory neuroplasticity related to the type of visual impairment, as well as underlying alterations in brain structural connectivity. We discuss the etiology and nature of visual impairments related to CVI, and how advanced neuroimaging techniques (i.e., diffusion-based imaging) may help uncover differences between ocular and cerebral causes of visual dysfunction. Revealing these differences may help in developing future strategies for the education and rehabilitation of individuals living with visual impairment.

  1. High-NaCl diet impairs dynamic renal blood flow autoregulation in rats with adenine-induced chronic renal failure.

    Science.gov (United States)

    Saeed, Aso; DiBona, Gerald F; Grimberg, Elisabeth; Nguy, Lisa; Mikkelsen, Minne Line Nedergaard; Marcussen, Niels; Guron, Gregor

    2014-03-15

    This study examined the effects of 2 wk of high-NaCl diet on kidney function and dynamic renal blood flow autoregulation (RBFA) in rats with adenine-induced chronic renal failure (ACRF). Male Sprague-Dawley rats received either chow containing adenine or were pair-fed an identical diet without adenine (controls). After 10 wk, rats were randomized to either remain on the same diet (0.6% NaCl) or to be switched to high 4% NaCl chow. Two weeks after randomization, renal clearance experiments were performed under isoflurane anesthesia and dynamic RBFA, baroreflex sensitivity (BRS), systolic arterial pressure variability (SAPV), and heart rate variability were assessed by spectral analytical techniques. Rats with ACRF showed marked reductions in glomerular filtration rate and renal blood flow (RBF), whereas mean arterial pressure and SAPV were significantly elevated. In addition, spontaneous BRS was reduced by ∼50% in ACRF animals. High-NaCl diet significantly increased transfer function fractional gain values between arterial pressure and RBF in the frequency range of the myogenic response (0.06-0.09 Hz) only in ACRF animals (0.3 ± 4.0 vs. -4.4 ± 3.8 dB; P renal failure by facilitating pressure transmission to the microvasculature.

  2. Cerebral hyperperfusion following carotid endarterectomy

    DEFF Research Database (Denmark)

    Schroeder, T; Sillesen, H; Sørensen, O;

    1987-01-01

    , occurred in the low pressure ratio group, while the hemispheric asymmetry on average was unchanged in the high pressure ratio group. This relative hyperemia was most pronounced 2 to 4 days following reconstruction. The marked hyperemia, absolute as well as relative, in patients with a low ICA/CCA pressure...... ratio suggests a temporary impairment of autoregulation. Special care should be taken to avoid postoperative hypertension in such patients, who typically have preoperative hypoperfusion, to avoid the occurrence of cerebral edema or hemorrhage....

  3. Gait Impairment in a Rat Model of Focal Cerebral Ischemia

    Directory of Open Access Journals (Sweden)

    Saara Parkkinen

    2013-01-01

    Full Text Available The availability of proper tests for gait evaluation following cerebral ischemia in rats has been limited. The automated, quantitative CatWalk system, which was initially designed to measure gait in models of spinal cord injury, neuropathic pain, and peripheral nerve injury, is said to be a useful tool for the study of motor impairment in stroke animals. Here we report our experiences of using CatWalk XT with rats subjected to transient middle cerebral artery occlusion (MCAO, during their six-week followup. Large corticostriatal infarct was confirmed by MRI in all MCAO rats, which was associated with severe sensorimotor impairment. In contrast, the gait impairment was at most mild, which is consistent with seemingly normal locomotion of MCAO rats. Many of the gait parameters were affected by body weight, walking speed, and motivation despite the use of a goal box. In addition, MCAO rats showed bilateral compensation, which was developed to stabilize proper locomotion. All of these interferences may confound the data interpretation. Taken together, the translational applicability of CatWalk XT in evaluating motor impairment and treatment efficacy remains to be limited at least in rats with severe corticostriatal infarct and loss of body weight.

  4. Autoregulation of brain circulation in severe arterial hypertension

    DEFF Research Database (Denmark)

    Strandgaard, S; Olesen, Jes; Skinhoj, E

    1973-01-01

    Cerebral blood flow was studied by the arteriovenous oxygen difference method in patients with severe hypertension and in normotensive controls. The blood pressure was lowered to study the lower limit of autoregulation (the pressure below which cerebral blood flow decreases) and the pressure limi...

  5. Development of visual acuity in children with cerebral visual impairment.

    Science.gov (United States)

    Lim, Mira; Soul, Janet S; Hansen, Ronald M; Mayer, D Luisa; Moskowitz, Anne; Fulton, Anne B

    2005-09-01

    To study the development of visual acuity in term-born children with cerebral visual impairment and a history of neonatal hypoxic-ischemic encephalopathy. We studied 19 term-born children, aged 6 months to 6 years, with moderate to severe neonatal hypoxic-ischemic encephalopathy and behaviors indicative of cerebral visual impairment. Longitudinal measures of grating acuity were obtained using preferential looking (PL) and visual evoked potential (VEP) procedures. Visual acuities at first and last visits were compared. The courses of acuity development in the 9 children who underwent both VEP and PL acuity assessment at 4 or more ages were compared with normal development. All children had measurable PL and VEP acuity, despite poor visual behavior. In nearly all, both PL and VEP acuity were below normal for age. For both PL and VEP measures, acuity at the last visit was, on average, 1 octave better than at the first visit, with a rate of improvement lower than normal. Although parallel courses of PL and VEP development occurred in many, substantial disparities in PL and VEP acuity were observed in others. Modest increases in PL and VEP grating acuity occur during early childhood in many of these patients. The rate of increase is lower than normal.

  6. Strictly Lobar Cerebral Microbleeds Are Associated With Cognitive Impairment.

    Science.gov (United States)

    Chung, Chih-Ping; Chou, Kun-Hsien; Chen, Wei-Ta; Liu, Li-Kuo; Lee, Wei-Ju; Chen, Liang-Kung; Lin, Ching-Po; Wang, Pei-Ning

    2016-10-01

    Different distributions of cerebral microbleeds (CMBs) are associated with distinct pathological mechanisms. Lobar CMBs are thought to be related to cerebral amyloid angiopathy, whereas deep or infratentorial CMBs are related to hypertensive vasculopathy. The present study aimed to evaluate the effects of CMBs and their locations on a variety of cognitive domains. Study subjects were selected from the community-based I-Lan Longitudinal Aging Study. We assessed cognitive domains, including verbal memory, language, visuospatial executive function, and verbal executive function. CMBs were evaluated using 3T susceptibility-weighted magnetic resonance imaging. We studied 959 subjects (mean±SD, 62.5±8.6 years; 425 [44.3%] men). CMBs were found in 14.2% of the population. We classified subjects with CMBs into 2 different groups based on the locations of their CMBs: (1) deep or infratentorial (85 subjects, 8.8% of population) and (2) strictly lobar (49, 5.1%). Multivariate linear analysis showed that strictly lobar CMBs were significantly associated with deficits in global cognitive function (Mini-Mental State Examination) and visuospatial executive function, as determined by the copy test of the Taylor complex figure test and the clock drawing test. We adjusted our results for age, sex, years of education, cardiovascular risk factors, and other markers of cerebral small vessel disease, lacunes, and white matter hyperintensity. Deep or infratentorial CMBs were not associated with changes in cognitive function in our population. Strictly lobar, but not deep or infratentorial, CMBs are associated with changes in cognitive function, especially in visuospatial executive functions. Cerebral amyloid angiopathy may be the underlying pathology associated with CMB-related cognitive impairment. © 2016 American Heart Association, Inc.

  7. Impaired autoregulation of blood flow in skeletal muscle and subcutaneous tissue in long-term Type 1 (insulin-dependent) diabetic patients with microangiopathy

    DEFF Research Database (Denmark)

    Faris, I; Vagn Nielsen, H; Henriksen, O

    1983-01-01

    Autoregulation of blood flow was studied in skeletal muscle and subcutaneous tissue in seven Type 1 (insulin-dependent) diabetic patients (median age: 36 years) with nephropathy and retinopathy and in eight normal subjects of the same age. Blood flow was measured by the local 133Xe washout...

  8. Evaluation of Cognitive Impairment After Posterior Cerebral Artery Infarction

    Directory of Open Access Journals (Sweden)

    Nilgün Çınar

    2013-02-01

    Full Text Available OBJECTIVE: The assessment of cognitive impairment after posterior cerebral artery (PCA ischemic infarction has not been well documanted. MATERIAL and METHODS: Twenty-six oriented, cooperated and non-aphasic consecutive patients with right or left (10/16 PCA infarction who were hospitalized between the years 2010-2012 were enrolled to the study. The branches of PSA were dealt as cortical and subcortical infarct under two groups. Short mental state examination test and cognitive test battery (CTB created from Wechsler memory scale (WMS, word-catogory association test and similarity test parameters were applied to the patients at the first week and third month follow-up visits and the groups were compared with each other. RESULTS: There was a significant improvement in catogory association test and total score of cognitive test battery (CTB in right PCA group, also there was a significant improvement in catogory association test in left PCA group at the first and 3th month evaluations. At the first month evaluations, total score of CTB of the subcortical segment PCA infarcts are lower than the cortical segment PCA infarcts. At the 3th month evaluations the scores increased in the both groups; but the scores in the subcortical PCA infarcts were lower than the cortical PCA infarcts. CONCLUSION: Our findings suggest that there was a cognitive impairment in patients with PCA infarction. The impairment in verbal fluency which was showed by catogory association test was found more prominent in the second evaluation. Further studies including functional imaging methods and cortical function tests are needed.

  9. Observation of Autoregulation Indices During Ventricular CSF Drainage After Aneurysmal Subarachnoid Hemorrhage : A Pilot Study

    NARCIS (Netherlands)

    Aries, Marcel J. H.; de Jong, Sytse F.; van Dijk, J. Marc C.; Regtien, Joost; Depreitere, Bart; Czosnyka, Marek; Smielewski, Peter; Elting, Jan Willem J.

    2015-01-01

    Cerebral autoregulation is increasingly recognized as a factor that requires evaluation when managing poor grade aneurysmal subarachno

  10. Impaired autoregulation of blood flow in subcutaneous tissue of long-term type 1 (insulin-dependent) diabetic patients with microangiopathy

    DEFF Research Database (Denmark)

    Kastrup, J; Nørgaard, T; Parving, H H

    1985-01-01

    Autoregulation of blood flow in subcutaneous tissue was studied at the level of the lateral malleolus in eight long-term Type 1 (insulin-dependent) diabetic patients with clinical microangiopathy, eight short-term Type 1 diabetic patients without clinical microangiopathy and seven healthy control...... by activation of the leg muscle vein pump (heel raising). Mean arterial blood pressure was thus varied between 60 and 160 mmHg. In normal and short-term diabetic subjects blood flow remained within 10% of control values during the changes in arterial blood pressure. In six of the eight Type 1 diabetic patients...

  11. The Danish Cerebral Palsy Registry. A registry on a specific impairment

    DEFF Research Database (Denmark)

    Uldall, P; Michelsen, Susan Ishøy; Topp, M

    2001-01-01

    Cerebral palsy (CP) is the commonest disabling impairment in childhood, with a prevalence of 2-3 per 1000 live births. The Danish Cerebral Palsy Registry is a research registry that contains cases of CP from birth year 1925 and has estimated the birth prevalence since 1950. Data on children with CP...

  12. The Danish Cerebral Palsy Registry. A registry on a specific impairment

    DEFF Research Database (Denmark)

    Uldall, P; Michelsen, S I; Topp, M;

    2001-01-01

    Cerebral palsy (CP) is the commonest disabling impairment in childhood, with a prevalence of 2-3 per 1000 live births. The Danish Cerebral Palsy Registry is a research registry that contains cases of CP from birth year 1925 and has estimated the birth prevalence since 1950. Data on children with CP...

  13. Gross motor function in children with spastic cerebral palsy and cerebral visual impairment: A comparison between outcomes of the original and the Cerebral Visual Impairment adapted Gross Motor Function Measure-88 (GMFM-88-CVI)

    NARCIS (Netherlands)

    Salavati, M.; Rameckers, E.A.A.; Waninge, A.; Krijnen, W.P.; Steenbergen, B.; Schans, C.P. van der

    2017-01-01

    Purpose: To investigate whether the adapted version of the Gross Motor Function Measure-88 (GMFM-88) for children with Cerebral Palsy (CP) and Cerebral Visual Impairment (CVI) results in higher scores. This is most likely to be a reflection of their gross motor function, however it may be the result

  14. Gross motor function in children with spastic Cerebral Palsy and Cerebral Visual Impairment : A comparison between outcomes of the original and the Cerebral Visual Impairment adapted Gross Motor Function Measure-88 (GMFM-88-CVI)

    NARCIS (Netherlands)

    Salavati, M.; Rameckers, E. A. A.; Waninge, A.; Krijnen, W. P.; Steenbergen, B.; van der Schans, C. P.

    2017-01-01

    Purpose: To investigate whether the adapted version of the Gross Motor Function Measure 88 (GMFM-88) for children with Cerebral Palsy (CP) and Cerebral Visual Impairment (CVI) results in higher scores. This is most likely to be a reflection of their gross motor function, however it may be the result

  15. Gross motor function in children with spastic cerebral palsy and cerebral visual impairment: A comparison between outcomes of the original and the Cerebral Visual Impairment adapted Gross Motor Function Measure-88 (GMFM-88-CVI)

    NARCIS (Netherlands)

    Salavati, M.; Rameckers, E.A.A.; Waninge, A.; Krijnen, W.P.; Steenbergen, B.; Schans, C.P. van der

    2017-01-01

    Purpose: To investigate whether the adapted version of the Gross Motor Function Measure-88 (GMFM-88) for children with Cerebral Palsy (CP) and Cerebral Visual Impairment (CVI) results in higher scores. This is most likely to be a reflection of their gross motor function, however it may be the result

  16. Development and face validity of a cerebral visual impairment motor questionnaire for children with cerebral palsy.

    Science.gov (United States)

    Salavati, M; Waninge, A; Rameckers, E A A; van der Steen, J; Krijnen, W P; van der Schans, C P; Steenbergen, B

    2017-01-01

    The objectives of this study were (i) to develop two cerebral visual impairment motor questionnaires (CVI-MQ's) for children with cerebral palsy (CP): one for children with Gross Motor Function Classification System (GMFCS) levels I, II and III and one for children with GMFCS levels IV and V; (ii) to describe their face validity and usability; and (iii) to determine their sensitivity and specificity. The initial versions of the two CVI-MQ's were developed based on literature. Subsequently, the Delphi method was used in two groups of experts, one familiar with CVI and one not familiar with CVI, in order to gain consensus about face validity and usability. The sensitivity and specificity of the CVI-MQ's were subsequently assessed in 82 children with CP with (n = 39) and without CVI (n = 43). With the receiver operating curve the cut-off scores were determined to detect possible presence or absence of CVI in children with CP. Both questionnaires showed very good face validity (percentage agreement above 96%) and good usability (percentage agreement 95%) for practical use. The CVI-MQ version for GMFCS levels I, II and III had a sensitivity of 1.00 and specificity of 0.96, with a cut-off score of 12 points or higher, and the version for GMFCS levels IV and V had a sensitivity of 0.97 and a specificity of 0.98, with a cut-off score of eight points or higher. The CVI-MQ is able to identify at-risk children with CP for the probability of having CVI. © 2016 John Wiley & Sons Ltd.

  17. Pathophysiology of impaired hand function in children with unilateral cerebral palsy

    NARCIS (Netherlands)

    Gordon, A.M.; Bleyenheuft, Y.; Steenbergen, B.

    2013-01-01

    Unilateral spastic cerebral palsy, caused by damage to the developing central nervous system, is characterized by motor impairments mainly lateralized to one side of the body, with hand impairments greatly contributing to functional limitations. The integrity of the motor areas and the corticospinal

  18. Pathophysiology of impaired hand function in children with unilateral cerebral palsy.

    NARCIS (Netherlands)

    Gordon, A.M.; Bleyenheuft, Y.; Steenbergen, B.

    2013-01-01

    Unilateral spastic cerebral palsy, caused by damage to the developing central nervous system, is characterized by motor impairments mainly lateralized to one side of the body, with hand impairments greatly contributing to functional limitations. The integrity of the motor areas and the corticospinal

  19. Pathophysiology of impaired hand function in children with unilateral cerebral palsy.

    NARCIS (Netherlands)

    Gordon, A.M.; Bleyenheuft, Y.; Steenbergen, B.

    2013-01-01

    Unilateral spastic cerebral palsy, caused by damage to the developing central nervous system, is characterized by motor impairments mainly lateralized to one side of the body, with hand impairments greatly contributing to functional limitations. The integrity of the motor areas and the corticospinal

  20. Pathophysiology of impaired hand function in children with unilateral cerebral palsy

    NARCIS (Netherlands)

    Gordon, A.M.; Bleyenheuft, Y.; Steenbergen, B.

    2013-01-01

    Unilateral spastic cerebral palsy, caused by damage to the developing central nervous system, is characterized by motor impairments mainly lateralized to one side of the body, with hand impairments greatly contributing to functional limitations. The integrity of the motor areas and the corticospinal

  1. Cerebral hemodynamics: concepts of clinical importance

    Directory of Open Access Journals (Sweden)

    Edson Bor-Seng-Shu

    2012-05-01

    Full Text Available Cerebral hemodynamics and metabolism are frequently impaired in a wide range of neurological diseases, including traumatic brain injury and stroke, with several pathophysiological mechanisms of injury. The resultant uncoupling of cerebral blood flow and metabolism can trigger secondary brain lesions, particularly in early phases, consequently worsening the patient's outcome. Cerebral blood flow regulation is influenced by blood gas content, blood viscosity, body temperature, cardiac output, altitude, cerebrovascular autoregulation, and neurovascular coupling, mediated by chemical agents such as nitric oxide (NO, carbon monoxide (CO, eicosanoid products, oxygen-derived free radicals, endothelins, K+, H+, and adenosine. A better understanding of these factors is valuable for the management of neurocritical care patients. The assessment of both cerebral hemodynamics and metabolism in the acute phase of neurocritical care conditions may contribute to a more effective planning of therapeutic strategies for reducing secondary brain lesions. In this review, the authors have discussed concepts of cerebral hemodynamics, considering aspects of clinical importance.

  2. Amyloid beta-peptide worsens cognitive impairment following cerebral ischemia-reperfusion injury*****

    Institute of Scientific and Technical Information of China (English)

    Bo Song; Qiang Ao; Ying Niu; Qin Shen; Huancong Zuo; Xiufang Zhang; Yandao Gong

    2013-01-01

    Amyloid β-peptide, a major component of senile plaques in Alzheimer’s disease, has been impli-cated in neuronal cel death and cognitive impairment. Recently, studies have shown that the pathogenesis of cerebral ischemia is closely linked with Alzheimer’s disease. In this study, a rat model of global cerebral ischemia-reperfusion injury was established via occlusion of four arteries;meanwhile, fibril ar amyloid β-peptide was injected into the rat lateral ventricle. The Morris water maze test and histological staining revealed that administration of amyloid β-peptide could further aggravate impairments to learning and memory and neuronal cel death in the hippocampus of rats subjected to cerebral ischemia-reperfusion injury. Western blot showed that phosphorylation of tau protein and the activity of glycogen synthase kinase 3β were significantly stronger in cerebral is-chemia-reperfusion injury rats subjected to amyloidβ-peptide administration than those undergoing cerebral ischemia-reperfusion or amyloidβ-peptide administration alone. Conversely, the activity of protein phosphatase 2A was remarkably reduced in rats with cerebral ischemia-reperfusion injury fol owing amyloidβ-peptide administration. These findings suggest that amyloidβ-peptide can po-tentiate tau phosphorylation induced by cerebral ischemia-reperfusion and thereby aggravate cog-nitive impairment.

  3. The longitudinal changes of BOLD response and cerebral hemodynamics from acute to subacute stroke. A fMRI and TCD study

    Directory of Open Access Journals (Sweden)

    Hamzei Farsin

    2009-12-01

    Full Text Available Abstract Background By mapping the dynamics of brain reorganization, functional magnetic resonance imaging MRI (fMRI has allowed for significant progress in understanding cerebral plasticity phenomena after a stroke. However, cerebro-vascular diseases can affect blood oxygen level dependent (BOLD signal. Cerebral autoregulation is a primary function of cerebral hemodynamics, which allows to maintain a relatively constant blood flow despite changes in arterial blood pressure and perfusion pressure. Cerebral autoregulation is reported to become less effective in the early phases post-stroke. This study investigated whether any impairment of cerebral hemodynamics that occurs during the acute and the subacute phases of ischemic stroke is related to changes in BOLD response. We enrolled six aphasic patients affected by acute stroke. All patients underwent a Transcranial Doppler to assess cerebral autoregulation (Mx index and fMRI to evaluate the amplitude and the peak latency (time to peak-TTP of BOLD response in the acute (i.e., within four days of stroke occurrence and the subacute (i.e., between five and twelve days after stroke onset stroke phases. Results As patients advanced from the acute to subacute stroke phase, the affected hemisphere presented a BOLD TTP increase (p = 0.04 and a deterioration of cerebral autoregulation (Mx index increase, p = 0.046. A similar but not significant trend was observed also in the unaffected hemisphere. When the two hemispheres were grouped together, BOLD TTP delay was significantly related to worsening cerebral autoregulation (Mx index increase (Spearman's rho = 0.734; p = 0.01. Conclusions The hemodynamic response function subtending BOLD signal may present a delay in peak latency that arises as patients advance from the acute to the subacute stroke phase. This delay is related to the deterioration of cerebral hemodynamics. These findings suggest that remodeling the fMRI hemodynamic response function in the

  4. Autoregulation of brain circulation in severe arterial hypertension

    DEFF Research Database (Denmark)

    Strandgaard, S; Olesen, Jes; Skinhoj, E

    1973-01-01

    Cerebral blood flow was studied by the arteriovenous oxygen difference method in patients with severe hypertension and in normotensive controls. The blood pressure was lowered to study the lower limit of autoregulation (the pressure below which cerebral blood flow decreases) and the pressure limit...... of brain hypoxia. Both limits were shifted upwards in the hypertensive patients, probably as a consequence of hypertrophy of the arteriolar walls. These findings have practical implications for antihypertensive therapy.When the blood pressure was raised some patients showed an upper limit of autoregulation...... beyond which an increase of cerebral blood flow above the resting value was seen without clinical symptoms. No evidence of vasospasm was found in any patient at high blood pressure. These observations may be of importance for the understanding of the pathogenesis of hypertensive encephalopathy....

  5. Aqueous extract of Cordyceps alleviates cerebral ischemia-induced short-term memory impairment in gerbils.

    Science.gov (United States)

    Lee, Sang-Hak; Ko, Il-Gyu; Kim, Sung-Eun; Hwang, Lakkyong; Jin, Jun-Jang; Choi, Hyun-Hee; Kim, Chang-Ju

    2016-04-01

    Cerebral ischemia is caused by reduced cerebral blood flow due to a transient or permanent cerebral artery occlusion. Ischemic injury in the brain leads to neuronal cell death, and eventually causes neurological impairments. Cordyceps, the name given to the fungi on insects, has abundant useful natural products with various biological activities. Cordyceps is known to have nephroprotective, hepatoprotective, anti-inflammatory, antioxidative, and antiapoptotic effects. We investigated the effects of Cordyceps on short-term memory, neuronal apoptosis, and cell proliferation in the hippocampal dentate gyrus following transient global ischemia in gerbils. For this study, a step-down avoidance test, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, immunohistochemistry for caspase-3 and 5-bromo-2'-de-oxyuridine, and western blot for Bax, Bcl-2, brain-derived neurotrophic factor (BDNF), and tyrosin kinase B were performed. In the present study, Cordyceps alleviated cerebral ischemia-induced short-term memory impairment. Cordyceps showed therapeutic effects through inhibiting cerebral ischemia-induced apoptosis in the hippocampus. Cordyceps suppressed cerebral ischemia-induced cell proliferation in the hippocampal dentate gyrus due to the reduced apoptotic neuronal cell death. Cordyceps treatment also enhanced BDNF and TrkB expressions in the hippocampus of ischemic gerbils. It can be suggested that Cordyceps overcomes cerebral ischemia-induced neuronal apoptosis, thus facilitates recovery following cerebral ischemia injury.

  6. Effects of propofol versus sevoflurane on cerebral oxygenation and cognitive outcome in patients with impaired cerebral oxygenation

    Directory of Open Access Journals (Sweden)

    Guo JY

    2016-01-01

    Full Text Available Jun-ying Guo,1,* Jie-yu Fang,1,* San-rong Xu,2 Ming Wei,1 Wen-qi Huang1 1Department of Anesthesia, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, 2Department of Anesthesia, Zhangzhou Municipal Hospital of Fujian Province, Zhangzhou, Fujian, People’s Republic of China *These authors contributed equally to this work Background: Postoperative neurocognitive dysfunction induced by anesthetics, particularly in elderly patients with impaired oxygenation, is a common complication of surgery and is eliciting increased interest in clinical practice. To investigate the effects of anesthetics on neurocognition, we compared the effects of propofol versus sevoflurane on cerebral oxygenation and cognitive outcome in patients with impaired cerebral oxygenation undergoing general anesthesia. Methods: Sixty-three patients with impaired cerebral oxygenation (jugular venous bulb oxygen saturation [SjvO2] <50% or cerebral blood flow/cerebral metabolic rate of oxygen ([CBF/CMRO2] ≤15% undergoing elective abdominal surgery were randomly allocated into propofol group (group P or sevoflurane group (group S. The clinical parameters and jugular venous bulb blood gas analysis were monitored throughout the surgical procedure. Cognitive function was assessed with the mini-mental state examination and Montreal Cognitive Assessment at day 1 and day 7 following surgery. S100β protein in plasma was measured using enzyme-linked immunosorbent assay. Results: The SjvO2 increased during anesthesia induction and surgery when compared to baseline but had no significant difference between group P and group S. When compared to baseline, the CBF/CMRO2 was increased only at the end of surgery and extubation in group P; however, the CBF/CMRO2 in group S was increased during anesthesia induction at 1 hour, 2 hours, end of surgery, and extubation. Furthermore, the CBF/CMRO2 in group S was significantly higher than that in group P during anesthesia

  7. Impaired cerebral blood flow and oxygenation during exercise in type 2 diabetic patients

    DEFF Research Database (Denmark)

    Kim, Yu-Sok; Seifert, Thomas; Brassard, Patrice

    2015-01-01

    cerebral artery blood flow velocity. Cerebral oxygenation and metabolism were evaluated from the arterial-to-venous differences for oxygen, glucose, and lactate. Blood pressure was comparable during exercise between the two groups. However, the partial pressure of arterial carbon dioxide was lower......Endothelial vascular function and capacity to increase cardiac output during exercise are impaired in patients with type 2 diabetes (T2DM). We tested the hypothesis that the increase in cerebral blood flow (CBF) during exercise is also blunted and, therefore, that cerebral oxygenation becomes...... at higher workloads in T2DM patients and their work capacity and increase in cardiac output were only ~80% of that established in the control subjects. CBF and cerebral oxygenation were reduced during exercise in T2DM patients (P

  8. T-type Ca(2+) channels and Autoregulation of Local Blood Flow

    DEFF Research Database (Denmark)

    Jensen, Lars Jørn; Nielsen, Morten Schak; Salomonsson, Max

    2017-01-01

    L-type voltage gated Ca(2+) channels are considered to be the primary source of calcium influx during the myogenic response. However, many vascular beds also express T-type voltage gated Ca(2+) channels. Recent studies suggest that these channels may also play a role in autoregulation. At low...... pressures (40-80 mm Hg) T-type channels affect myogenic responses in cerebral and mesenteric vascular beds. T-type channels also seem to be involved in skeletal muscle autoregulation. This review discusses the expression and role of T-type voltage gated Ca(2+) channels in the autoregulation of several...

  9. Obesity Interacts with Cerebral Hypoperfusion to Exacerbate Cognitive Impairment in Older Adults with Heart Failure

    Directory of Open Access Journals (Sweden)

    Michael L. Alosco

    2012-10-01

    Full Text Available Background: Cerebral hypoperfusion accompanies heart failure (HF and is associated with reduced cognitive performance. Obesity is prevalent in persons with HF and is also a likely contributor to cognitive function, as it has been independently linked to cognitive impairment in healthy individuals. The current study examined the association between obesity and cognitive performance among older adults with HF and whether obesity interacts with cerebral hypoperfusion to exacerbate cognitive impairment. Methods: Patients with HF (n = 99, 67.46 ± 11.36 years of age completed neuropsychological testing and impedance cardiography. Cerebral blood flow velocity (CBF-V measured by transcranial Doppler sonography quantified cerebral perfusion and body mass index (BMI operationalized obesity. Results: A hierarchical regression analysis showed that lower CBF-V was associated with reduced performance on tests of attention/executive function and memory. Elevated BMI was independently associated with reduced attention/executive function and language test performance. Notably, a significant interaction between CBF-V and BMI indicated that a combination of hypoperfusion and high BMI has an especially adverse influence on attention/executive function in HF patients. Conclusions: The current findings suggest that cerebral hypoperfusion and obesity interact to impair cognitive performance in persons with HF. These results may have important clinical implications, as HF patients who are at high risk for cerebral hypoperfusion may benefit from weight reduction.

  10. Studies on the cerebral circulation of the baboon in acutely induced hypertension

    DEFF Research Database (Denmark)

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

    1976-01-01

    The upper limit autoregulation of cerebral blood flow was investigated in eight young baboons with the intracarotid 133xenon clearance method. Blood pressure was increased by intravenous angiotensin infusion. Autoregulation was effective during blood pressure increase from normotensive levels...

  11. Dependency of cerebral blood flow upon mean arterial pressure in patients with acute bacterial meningitis

    DEFF Research Database (Denmark)

    Møller, Kirsten; Larsen, Fin Stolze; Qvist, Jesper;

    2000-01-01

    OBJECTIVE: Patients with acute bacterial meningitis are often treated with sympathomimetics to maintain an adequate mean arterial pressure (MAP). We studied the influence of such therapy on cerebral blood flow (CBF). DESIGN: Prospective physiologic trial. SETTING: The Department of Infectious...... Diseases, Copenhagen University Hospital, Denmark. PATIENTS: Sixteen adult patients with acute bacterial meningitis. INTERVENTION: Infusion of norepinephrine to increase MAP. MEASUREMENTS: During a rise in MAP induced by norepinephrine infusion, we measured relative changes in CBF by transcranial Doppler...... bacterial meningitis, CBF autoregulation is impaired. With recovery from meningitis, the cerebral vasculature regains the ability to maintain cerebral perfusion at a constant level despite variations in MAP....

  12. Impact of Cerebral Visual Impairments on Motor Skills: Implications for Developmental Coordination Disorders

    OpenAIRE

    2016-01-01

    Cerebral visual impairment (CVI) has become the primary cause of visual impairment and blindness in children in industrialized countries. Its prevalence has increased sharply, due to increased survival rates of children who sustain severe neurological conditions during the perinatal period. Improved diagnosis has probably contributed to this increase. As in adults, the nature and severity of CVI in children relate to the cause, location and extent of damage to the brain. In the present paper,...

  13. Impaired fasting blood glucose is associated to cognitive impairment and cerebral atrophy in middle-aged non-human primates

    Science.gov (United States)

    Djelti, Fathia; Dhenain, Marc; Terrien, Jérémy; Picq, Jean-Luc; Hardy, Isabelle; Champeval, Delphine; Perret, Martine; Schenker, Esther; Epelbaum, Jacques; Aujard, Fabienne

    2017-01-01

    Age-associated cognitive impairment is a major health and social issue because of increasing aged population. Cognitive decline is not homogeneous in humans and the determinants leading to differences between subjects are not fully understood. In middle-aged healthy humans, fasting blood glucose levels in the upper normal range are associated with memory impairment and cerebral atrophy. Due to a close evolutional similarity to Man, non-human primates may be useful to investigate the relationships between glucose homeostasis, cognitive deficits and structural brain alterations. In the grey mouse lemur, Microcebus murinus, spatial memory deficits have been associated with age and cerebral atrophy but the origin of these alterations have not been clearly identified. Herein, we showed that, on 28 female grey mouse lemurs (age range 2.4-6.1 years-old), age correlated with impaired fasting blood glucose (rs=0.37) but not with impaired glucose tolerance or insulin resistance. In middle-aged animals (4.1-6.1 years-old), fasting blood glucose was inversely and closely linked with spatial memory performance (rs=0.56) and hippocampus (rs=−0.62) or septum (rs=−0.55) volumes. These findings corroborate observations in humans and further support the grey mouse lemur as a natural model to unravel mechanisms which link impaired glucose homeostasis, brain atrophy and cognitive processes. PMID:28039490

  14. Story Retelling and Language Ability in School-Aged Children with Cerebral Palsy and Speech Impairment

    Science.gov (United States)

    Nordberg, Ann; Dahlgren Sandberg, Annika; Miniscalco, Carmela

    2015-01-01

    Background: Research on retelling ability and cognition is limited in children with cerebral palsy (CP) and speech impairment. Aims: To explore the impact of expressive and receptive language, narrative discourse dimensions (Narrative Assessment Profile measures), auditory and visual memory, theory of mind (ToM) and non-verbal cognition on the…

  15. Inferential Ability in Children with Cerebral Palsy, Spina Bifida and Pragmatic Language Impairment

    Science.gov (United States)

    Holck, Pernille; Sandberg, Annika Dahlgren; Nettelbladt, Ulrika

    2010-01-01

    The aim of the study was to investigate and compare the ability to make inferences in three groups of children ranging from 5;2 to 10;9 years: 10 children with cerebral palsy (CP), 10 children with spina bifida and hydrocephalus (SBH) and 10 children with pragmatic language impairment (PLI). The relationship between inferential and literal…

  16. Children with Cerebral Palsy, Spina Bifida and Pragmatic Language Impairment: Differences and Similarities in Pragmatic Ability

    Science.gov (United States)

    Holck, Pernille; Nettelbladt, Ulrika; Sandberg, Annika Dahlgren

    2009-01-01

    Pragmatically related abilities were studied in three clinical groups of children from 5 to 11 years of age; children with cerebral palsy (CP; n = 10), children with spina bifida and hydrocephalus (SBH; n = 10) and children with pragmatic language impairment (PLI; n = 10), in order to explore pragmatic abilities within each group. A range of…

  17. Inferential Ability in Children with Cerebral Palsy, Spina Bifida and Pragmatic Language Impairment

    Science.gov (United States)

    Holck, Pernille; Sandberg, Annika Dahlgren; Nettelbladt, Ulrika

    2010-01-01

    The aim of the study was to investigate and compare the ability to make inferences in three groups of children ranging from 5;2 to 10;9 years: 10 children with cerebral palsy (CP), 10 children with spina bifida and hydrocephalus (SBH) and 10 children with pragmatic language impairment (PLI). The relationship between inferential and literal…

  18. Children with Cerebral Palsy, Spina Bifida and Pragmatic Language Impairment: Differences and Similarities in Pragmatic Ability

    Science.gov (United States)

    Holck, Pernille; Nettelbladt, Ulrika; Sandberg, Annika Dahlgren

    2009-01-01

    Pragmatically related abilities were studied in three clinical groups of children from 5 to 11 years of age; children with cerebral palsy (CP; n = 10), children with spina bifida and hydrocephalus (SBH; n = 10) and children with pragmatic language impairment (PLI; n = 10), in order to explore pragmatic abilities within each group. A range of…

  19. My Voice Heard: The Journey of a Young Man with a Cerebral Visual Impairment

    Science.gov (United States)

    Macintyre-Beon, Catriona; Mitchell, Kate; Gallagher, Ian; Cockburn, Debbie; Dutton, Gordon N.; Bowman, Richard

    2012-01-01

    This longitudinal case study presents John's journey through childhood and adolescence, living with visual difficulties associated with a cerebral visual impairment. It highlights the day-to-day problems that John encountered, giving practical solutions and strategies that have enabled his dream of going to a university to be realized. John and…

  20. Closed-Loop Dynamic Modeling of Cerebral Hemodynamics

    Science.gov (United States)

    Marmarelis, V. Z.; Shin, D. C.; Orme, M. E.; Zhang, R.

    2013-01-01

    The dynamics of cerebral hemodynamics have been studied extensively because of their fundamental physiological and clinical importance. In particular, the dynamic processes of cerebral flow autoregulation and CO2 vasomotor reactivity have attracted broad attention because of their involvement in a host of pathologies and clinical conditions (e.g. hypertension, syncope, stroke, traumatic brain injury, vascular dementia, Alzheimer’s disease, mild cognitive impairment etc.). This raises the prospect of useful diagnostic methods being developed on the basis of quantitative models of cerebral hemodynamics, if cerebral vascular dysfunction can be quantified reliably from data collected within practical clinical constraints. This paper presents a modeling method that utilizes beat-to-beat measurements of mean arterial blood pressure, cerebral blood flow velocity and end-tidal CO2 (collected non-invasively under resting conditions) to quantify the dynamics of cerebral flow autoregulation (CFA) and cerebral vasomotor reactivity (CVMR). The unique and novel aspect of this dynamic model is that it is nonlinear and operates in a closed-loop configuration. PMID:23292615

  1. Gross motor function, functional skills and caregiver assistance in children with spastic cerebral palsy (CP) with and without cerebral visual impairment (CVI)

    NARCIS (Netherlands)

    Salavati, M.; Rameckers, E.A.A.; Steenbergen, B.; Schans, C.P. van der

    2014-01-01

    Aim: To determine whether the level of gross motor function and functional skills in children with cerebral palsy (CP) and cerebral visual impairment (CVI) as well as caregiver assistance are lower in comparison with the corresponding group of children experiencing CP without CVI. Method: Data aggre

  2. Gross motor function, functional skills and caregiver assistance in children with spastic cerebral palsy (CP) with and without cerebral visual impairment (CVI)

    NARCIS (Netherlands)

    Salavati, M.; Rameckers, E.A.A.; Steenbergen, B.; Schans, C.P. van der

    2014-01-01

    Aim: To determine whether the level of gross motor function and functional skills in children with cerebral palsy (CP) and cerebral visual impairment (CVI) as well as caregiver assistance are lower in comparison with the corresponding group of children experiencing CP without CVI. Method: Data

  3. Reliability of the modified Paediatric Evaluation of Disability Inventory, Dutch version (PEDI-NL) for children with cerebral palsy and cerebral visual impairment

    NARCIS (Netherlands)

    Salavati, M.; Waninge, A.; Rameckers, E.A.A.; Blecourt, A.C. de; Krijnen, W.P.; Steenbergen, B.; Schans, C.P. van der

    2015-01-01

    PURPOSE: The aims of this study were to adapt the Paediatric Evaluation of Disability Inventory, Dutch version (PEDI-NL) for children with cerebral visual impairment (CVI) and cerebral palsy (CP) and determine test-retest and inter-respondent reliability. METHOD: The Delphi method was used to gain

  4. Reliability of the modified Paediatric Evaluation of Disability Inventory, Dutch version (PEDI-NL) for children with cerebral palsy and cerebral visual impairment

    NARCIS (Netherlands)

    Salavati, M.; Waninge, A.; Rameckers, E. A. A.; de Blecourt, A. C. E.; Krijnen, W. P.; Steenbergen, B.; van der Schans, C. P.

    Purpose: The aims of this study were to adapt the Paediatric Evaluation of Disability Inventory, Dutch version (PEDI-NL) for children with cerebral visual impairment (CVI) and cerebral palsy (CP) and determine test-retest and inter-respondent reliability. Method: The Delphi method was used to gain

  5. Reliability of the modified Gross Motor Function Measure-88 (GMFM-88) for children with both Spastic Cerebral Palsy and Cerebral Visual Impairment : A preliminary study

    NARCIS (Netherlands)

    Salavati, M.; Krijnen, W. P.; Rameckers, E. A. A.; Looijestijn, P. L.; Maathuis, C. G. B.; van der Schans, C. P.; Steenbergen, B.

    2015-01-01

    Purpose: The aims of this study were to adapt the Gross Motor Function Measure-88 (GMFM-88) for children with Cerebral Palsy (CP) and Cerebral Visual Impairment (CVI) and to determine the test-retest and interobserver reliability of the adapted version. Method: Sixteen paediatric physical therapists

  6. Spontaneous low-frequency oscillations in cerebral vessels

    DEFF Research Database (Denmark)

    Schytz, Henrik W; Hansson, Andreas; Phillip, Dorte

    2010-01-01

    The etiology behind and physiological significance of spontaneous oscillations in the low-frequency spectrum in both systemic and cerebral vessels remain unknown. Experimental studies have proposed that spontaneous oscillations in cerebral blood flow reflect impaired cerebral autoregulation (CA......). Analysis of CA by measurement of spontaneous oscillations in the low-frequency spectrum in cerebral vessels might be a useful tool for assessing risk and investigating different treatment strategies in carotid artery disease (CAD) and stroke. We reviewed studies exploring spontaneous oscillations...... coefficients in the time domain are the most frequently used parameters for analyzing spontaneous oscillations in systemic and cerebral vessels. At present, there is no gold standard for analyzing spontaneous oscillations in the low-frequency spectrum, and simplistic models of CA have failed to predict...

  7. 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.

  8. Structural Equation Modeling of Motor Impairment, Gross Motor Function, and the Functional Outcome in Children with Cerebral Palsy

    Science.gov (United States)

    Park, Eun-Young; Kim, Won-Ho

    2013-01-01

    Physical therapy intervention for children with cerebral palsy (CP) is focused on reducing neurological impairments, improving strength, and preventing the development of secondary impairments in order to improve functional outcomes. However, relationship between motor impairments and functional outcome has not been proved definitely. This study…

  9. Impairment of neuropsychological function in patients with hemodynamic cerebral ischemia and efficacy of bypass surgery

    Energy Technology Data Exchange (ETDEWEB)

    Sasoh, Masayuki [Iwate Medical Univ., Morioka (Japan). School of Medicine

    1999-08-01

    In order to evaluate the relation between neuropsychological functions and hemodynamic cerebral ischemia, the author analyzed neuropsychological examination and the cerebral blood flow and metabolism of patients before and after bypass surgery. Twenty-five patients were defined by clinical and laboratory criteria as suffering from hemodynamic cerebral ischemia. All patients had one or more episodes of focal cerebral ischemia due to unilateral internal carotid or middle cerebral artery occlusion. Computerized tomography scans either were normal or showed evidence of watershed infarction. Based on these criteria, superficial temporal artery-proximal middle cerebral artery anastomosis was performed. The baseline cerebral blood flow (CBF), oxygen extraction fraction (OEF), cerebral metabolic rate of oxygen (CMRO{sub 2}) and cerebrovascular reserve capacity (CVRC) were studied using positron emission computerized tomography (PET) and the acetazolamide test. Neuropsychological evaluations including Hasegawa Dementia Scale-Revised, Mini-Mental State and Wechsler Adult Intelligence Scale-Revised (WAIS-R), and PET study were completed one month after the last ischemic event and 3-6 months after the operation. A significant negative correlation was observed between OEF and neuropsychological functions. Postoperative neuropsychological functions showed significant improvement. Significant correlations were observed for {delta}WAIS-R (preoperative WAIS-R postoperative WAIS-R) versus preoperative CMRO{sub 2} (r=0.52), for {delta}WAIS-R versus preoperative OEF (r=0.47). In view of these findings, the author concludes that elevation of OEF impairs neuropsychological functions and bypass surgery improves neuropsychological functions in patients with normal CMRO{sub 2} and elevated OEF. (author)

  10. Cerebral blood flow response to hypoglycemia is altered in patients with type 1 diabetes and impaired awareness of hypoglycemia.

    Science.gov (United States)

    Wiegers, Evita C; Becker, Kirsten M; Rooijackers, Hanne M; von Samson-Himmelstjerna, Federico C; Tack, Cees J; Heerschap, Arend; de Galan, Bastiaan E; van der Graaf, Marinette

    2017-06-01

    It is unclear whether cerebral blood flow responses to hypoglycemia are altered in people with type 1 diabetes and impaired awareness of hypoglycemia. The aim of this study was to investigate the effect of hypoglycemia on both global and regional cerebral blood flow in type 1 diabetes patients with impaired awareness of hypoglycemia, type 1 diabetes patients with normal awareness of hypoglycemia and healthy controls ( n = 7 per group). The subjects underwent a hyperinsulinemic euglycemic-hypoglycemic glucose clamp in a 3 T MR system. Global and regional changes in cerebral blood flow were determined by arterial spin labeling magnetic resonance imaging, at the end of both glycemic phases. Hypoglycemia generated typical symptoms in patients with type 1 diabetes and normal awareness of hypoglycemia and healthy controls, but not in patients with impaired awareness of hypoglycemia. Conversely, hypoglycemia increased global cerebral blood flow in patients with impaired awareness of hypoglycemia, which was not observed in the other two groups. Regionally, hypoglycemia caused a redistribution of cerebral blood flow towards the thalamus of both patients with normal awareness of hypoglycemia and healthy controls, consistent with activation of brain regions associated with the autonomic response to hypoglycemia. No such redistribution was found in the patients with impaired awareness of hypoglycemia. An increase in global cerebral blood flow may enhance nutrient supply to the brain, hence suppressing symptomatic awareness of hypoglycemia. Altogether these results suggest that changes in cerebral blood flow during hypoglycemia contribute to impaired awareness of hypoglycemia.

  11. Endothelin-1 Mediates Brain Microvascular Dysfunction Leading to Long-Term Cognitive Impairment in a Model of Experimental Cerebral Malaria.

    Directory of Open Access Journals (Sweden)

    Brandi D Freeman

    2016-03-01

    Full Text Available Plasmodium falciparum infection causes a wide spectrum of diseases, including cerebral malaria, a potentially life-threatening encephalopathy. Vasculopathy is thought to contribute to cerebral malaria pathogenesis. The vasoactive compound endothelin-1, a key participant in many inflammatory processes, likely mediates vascular and cognitive dysfunctions in cerebral malaria. We previously demonstrated that C57BL6 mice infected with P. berghei ANKA, our fatal experimental cerebral malaria model, sustained memory loss. Herein, we demonstrate that an endothelin type A receptor (ETA antagonist prevented experimental cerebral malaria-induced neurocognitive impairments and improved survival. ETA antagonism prevented blood-brain barrier disruption and cerebral vasoconstriction during experimental cerebral malaria, and reduced brain endothelial activation, diminishing brain microvascular congestion. Furthermore, exogenous endothelin-1 administration to P. berghei NK65-infected mice, a model generally regarded as a non-cerebral malaria negative control for P. berghei ANKA infection, led to experimental cerebral malaria-like memory deficits. Our data indicate that endothelin-1 is critical in the development of cerebrovascular and cognitive impairments with experimental cerebral malaria. This vasoactive peptide may thus serve as a potential target for adjunctive therapy in the management of cerebral malaria.

  12. Endothelin-1 Mediates Brain Microvascular Dysfunction Leading to Long-Term Cognitive Impairment in a Model of Experimental Cerebral Malaria.

    Directory of Open Access Journals (Sweden)

    Brandi D Freeman

    2016-03-01

    Full Text Available Plasmodium falciparum infection causes a wide spectrum of diseases, including cerebral malaria, a potentially life-threatening encephalopathy. Vasculopathy is thought to contribute to cerebral malaria pathogenesis. The vasoactive compound endothelin-1, a key participant in many inflammatory processes, likely mediates vascular and cognitive dysfunctions in cerebral malaria. We previously demonstrated that C57BL6 mice infected with P. berghei ANKA, our fatal experimental cerebral malaria model, sustained memory loss. Herein, we demonstrate that an endothelin type A receptor (ETA antagonist prevented experimental cerebral malaria-induced neurocognitive impairments and improved survival. ETA antagonism prevented blood-brain barrier disruption and cerebral vasoconstriction during experimental cerebral malaria, and reduced brain endothelial activation, diminishing brain microvascular congestion. Furthermore, exogenous endothelin-1 administration to P. berghei NK65-infected mice, a model generally regarded as a non-cerebral malaria negative control for P. berghei ANKA infection, led to experimental cerebral malaria-like memory deficits. Our data indicate that endothelin-1 is critical in the development of cerebrovascular and cognitive impairments with experimental cerebral malaria. This vasoactive peptide may thus serve as a potential target for adjunctive therapy in the management of cerebral malaria.

  13. Impaired consciousness revealing a cerebral amebiasis in an immunocompetent adult

    Directory of Open Access Journals (Sweden)

    Hanane Ezzouine

    2012-01-01

    Full Text Available Amebiasis is a parasitic infection with manifestations, mainly digestives. It is rarely described extra-gastrointestinal locations including the brain. We report the case of a patient aged 42, made five months earlier for an appendectomy, and was admitted to the ICU after a convalescent stable uncomplicated. At admission, he was 12/15 in Glasgow and had a right hemiplegia. Brain CT revealed a discrete diffuse hypodensities perilesional edema. An abdominal ultrasound found an aspect for multiple hepatic abscesses. Abscess puncture was performed, which was not conclusive, and no seed could be identified. On Ultrasound, no cardiac abnormalities were found, and no endocarditis was present. And since the appearance macroscopic (chocolate-brown, amebic serology is performed and has been highly positive. The therapeutic management included an intubation and ventilation as well as a tri-antibiotic-based ceftriaxon, metronidazol and gentamycin. Confirmation of amebiasis required high doses of metronidazol for an extended period. The replay of the play was an appendectomy for an amebome. Evolution was favorable. Amebiasis can have extraintestinal locations, issues to think about including the cerebral forms.

  14. [Magnetic resonance spectroscopic study of memory impairment after cerebral infarction treated with electroacupuncture].

    Science.gov (United States)

    Zhang, Jianbo; Shen, Yunxia

    2015-07-01

    To study the impacts of electroacupuncture (EA) on memory impairment after cerebral infarction through the observation of hydrogen proton magnetic resonance spectroscopy (1H-MRS) of brain tissue metabolites in the patients of cerebral infarction. Sixty cases of memory impairment after cerebral infarction were randomized into an observation group and a control group, 30 cases in each one. The conventional rehabilitation training and medication were applied to all the patients. In the observation group, beside the basic treatment, EA was applied to bilateral Ezhongxian (MS 1), Dingzhongxian (MS 5), Dingniehouxiexian (MS 7), Hegu (LI 4), Taichong (LR 3), Zusanli (ST 36), Taixi (KI 3), Xuanzhong (GB 39) and Fengchi (GB 20). The treatment was given once a day, 5 times a week, for 8 weeks. The clinical memory scale was used for the score evaluation before and after treatment in all the patients. The magnetic resonance image (MRI) and 1H-MRS scanning were applied to the head. The ratio of N-acetyl aspartate (NAA) and creatine (Cr) and the ratio of choline (Cho) and Cr were determined in the foci of cerebral infarction. Eight weeks later, the scores of clinical memory scale were all increased after treatment as compared with those before treatment in the two group (all Prehabilitation training, EA improves the metabolism of brain tissue and memory function of the patients. The efficacy of this therapy is better than that of medication combined with rehabilitation training.

  15. Effect of Vestibular Impairment on Cerebral Blood Flow Response to Dynamic Roll Tilt

    Science.gov (United States)

    Serrador, J. M.; Black, F. O.; Schlgel, Todd T.; Lipsitz, L. A.; Wood, S. J.

    2008-01-01

    Change to upright posture results in reductions in cerebral perfusion pressure due to hydrostatic pressure changes related to gravity. Since vestibular organs, specifically the otoliths, provide information on position relative to gravity, vestibular inputs may assist in adaptation to the upright posture. The goal of this study was to examine the effect of direct vestibular stimulation on cerebral blood flow (CBF). To examine the role of otolith inputs we screened 165 subjects for vestibular function and classified subjects as either normal or impaired based on ocular torsion. Ocular torsion, an indication of otolith function, was assessed during sinusoidal roll tilt of 20 degrees at 0.01 Hz (100 sec per cycle). Subjects with torsion one SD below the mean were classified as impaired while subjects one SD above the mean were considered normal. During one session subjects were placed in a chair that was sinusoidally rotated 25 degrees in the roll plane at five frequencies: 0.25 & 0.125 Hz for 80 sec, 0.0625 Hz for 160 sec and 0.03125 Hz and 0.015625 Hz for 320 sec. During testing, CBF (transcranial Doppler), blood pressure (Finapres), and end tidal CO2 (Puritan Bennet) were measured continuously. Ocular torsion was assessed from infrared images of the eyes. All rotations were done in the dark with subjects fixated on a red LED directly at the center of rotation. In the normal group, dynamic tilt resulted in significant changes in both blood pressure and cerebral blood flow velocity that was related to the frequency of stimulus. In contrast the impaired group did not show similar patterns. As expected normal subjects demonstrated significant ocular torsion that was related to stimulus frequency while impaired subjects had minimal changes. These data suggest that vestibular inputs have direct effects on cerebral blood flow regulation during dynamic tilt. Supported by NASA.

  16. Citicoline Protects Against Cognitive Impairment in a Rat Model of Chronic Cerebral Hypoperfusion

    OpenAIRE

    Lee, Hyun Joon; Kang, Ji Seung; Kim, Yeong In

    2008-01-01

    Background and purpose Cerebral white matter (WM) lesions are frequently observed in human cerebrovascular diseases, and are believed to be responsible for cognitive impairment. Various neuroprotective agents can suppress this type of WM or neuronal damage. In this study, we investigated whether citicoline, a drug used to treat acute ischemic stroke, can attenuate WM lesions and cognitive decline caused by chronic hypoperfusion in the rat. Methods Animals were divided into immediate- and dela...

  17. The spectrum of cerebral visual impairment as a sequel to premature birth: an overview.

    Science.gov (United States)

    Dutton, Gordon N

    2013-08-01

    In children born prematurely, impairment of vision due to damage to the brain is more common than due to retinopathy of prematurity. Yet, the diagnosis of cerebral visual impairment may be missed. The subject of cerebral visual impairment in children is reviewed in order to explain and draw attention to the types of visual deficits and behaviours that may result as a sequel to premature birth. A wide range of sources of data has been employed to assemble this overview. The principal reference source is PubMed. The material presented highlights the origin and range of visual deficits that result from damage to the brain, related to premature birth. Deficits of primary visual functions, perceptual dysfunction, simultanagnostic visual disorders and impaired visual guidance of movement (optic ataxia), as well as disorders of visual attention and memory, can occur in a variety of combinations and degrees. The resulting behavioural outcomes are described. Identification and characterisation of impaired vision, due to prematurity associated damage to the brain, are essential. This is required so as to ensure that affected children are not inappropriately disadvantaged on account of the diagnosis being missed or inadequately acted upon, but instead, they are managed optimally, both at home and at school, so that their development is enhanced to the greatest advantage.

  18. Impaired Cerebral Mitochondrial Oxidative Phosphorylation Function in a Rat Model of Ventricular Fibrillation and Cardiopulmonary Resuscitation

    Directory of Open Access Journals (Sweden)

    Jun Jiang

    2014-01-01

    Full Text Available Postcardiac arrest brain injury significantly contributes to mortality and morbidity in patients suffering from cardiac arrest (CA. Evidence that shows that mitochondrial dysfunction appears to be a key factor in tissue damage after ischemia/reperfusion is accumulating. However, limited data are available regarding the cerebral mitochondrial dysfunction during CA and cardiopulmonary resuscitation (CPR and its relationship to the alterations of high-energy phosphate. Here, we sought to identify alterations of mitochondrial morphology and oxidative phosphorylation function as well as high-energy phosphates during CA and CPR in a rat model of ventricular fibrillation (VF. We found that impairment of mitochondrial respiration and partial depletion of adenosine triphosphate (ATP and phosphocreatine (PCr developed in the cerebral cortex and hippocampus following a prolonged cardiac arrest. Optimal CPR might ameliorate the deranged phosphorus metabolism and preserve mitochondrial function. No obvious ultrastructural abnormalities of mitochondria have been found during CA. We conclude that CA causes cerebral mitochondrial dysfunction along with decay of high-energy phosphates, which would be mitigated with CPR. This study may broaden our understanding of the pathogenic processes underlying global cerebral ischemic injury and provide a potential therapeutic strategy that aimed at preserving cerebral mitochondrial function during CA.

  19. Dynamic Cerebral Autoregulation after Cardiopulmonary Bypass

    DEFF Research Database (Denmark)

    Christiansen, Claus Behrend; Berg, Ronan M G; Plovsing, Ronni

    2016-01-01

    volunteers (gain: 1.24 [0.94-1.49] vs. 1.22 [1.06-1.34] cm mm Hg(-1) s(-1), p = 0.97; phase: 0.33 [0.15-0.56] vs. 0.69 [0.50-0.77] rad, p = 0.09). Neurocognitive testing showed a perioperative decline in the Letter Digit Coding Score (p = 0.04), while weaker dCA was associated with a lower Stroop Color Word...... in eight patients 6 hours after the cessation of CPB; 10 healthy volunteers served as controls. Neurocognitive function was assessed by four specific tests 1 day prior to and 3 days after CPB. Results Even though patients exhibited systemic inflammation and anemic hypoxemia, dCA was similar to healthy...... Test (rho =  - 0.90; p = 0.01). Discussion and Conclusion We found no changes in dCA 6 hours after CPB. However, based on the data at hand, it cannot be ruled out that changes in dCA predispose to POCD, which calls for larger studies that assess the potential impact of dCA in the early postoperative...

  20. Intraoperative blood pressure and cerebral perfusion: strategies to clarify hemodynamic goals.

    Science.gov (United States)

    Williams, Monica; Lee, Jennifer K

    2014-07-01

    Blood pressure can vary considerably during anesthesia. If blood pressure falls outside the limits of cerebrovascular autoregulation, children can become at risk of cerebral ischemic or hyperemic injury. However, the blood pressure limits of autoregulation are unclear in infants and children, and these limits can shift after brain injury. This article will review autoregulation, considerations for the hemodynamic management of children with brain injuries, and research on autoregulation monitoring techniques.

  1. Intraoperative blood pressure and cerebral perfusion: strategies to clarify hemodynamic goals

    OpenAIRE

    Williams, Monica; Lee, Jennifer K.

    2014-01-01

    Blood pressure can vary considerably during anesthesia. If blood pressure falls outside the limits of cerebrovascular autoregulation, children can become at risk of cerebral ischemic or hyperemic injury. However, the blood pressure limits of autoregulation are unclear in infants and children, and these limits can shift after brain injury. This article will review autoregulation, considerations for the hemodynamic management of children with brain injuries, and research on autoregulation monit...

  2. Impaired Cerebral Hemodynamics and Cognitive Performance in Patients with Atherothrombotic Disease.

    Science.gov (United States)

    Haratz, Salo; Weinstein, Galit; Molshazki, Noa; Beeri, Michal Schnaider; Ravona-Springer, Ramit; Marzeliak, Oleg; Goldbourt, Uri; Tanne, David

    2015-01-01

    Patients with pre-existing atherothrombotic disease are prone to cognitive impairment. We tested whether impaired cerebrovascular reactivity (CVR), a marker of cerebral microvascular hemodynamic dysfunction, is associated with poorer cognitive scores among patients with and without carotid large-vessel disease. A subgroup of non-demented patients with chronic coronary heart disease followed-up for 15 ± 3 years was assessed for cognitive function (Neurotrax Computerized Cognitive Battery; scaled to an IQ style scale with a mean of 100 and SD of 15) and for CVR using the breath-holding index (BHI) with transcranial Doppler and for carotid plaques using ultrasound. We assessed cognitive scores in specific domains in patients with and without impaired CVR (BHI hemodynamics in cognitive performance.

  3. Autoregulation of glomerular filtration rate during spironolactone treatment in hypertensive patients with type 1 diabetes: a randomized crossover trial

    DEFF Research Database (Denmark)

    Schjoedt, K.J.; Christensen, P.K.; Jorsal, A.;

    2009-01-01

    BACKGROUND: Autoregulation of GFR, i.e. maintenance of relative constancy of GFR despite variations in mean arterial pressure (MAP) >80 mmHg, is impaired in diabetic kidney disease; furthermore, some antihypertensive drugs may jeopardize autoregulation. The aim of our study was to establish...... if spironolactone affects the ability to autoregulate GFR. METHODS: Sixteen hypertensive type 1 diabetic patients with persistent normoalbuminuria (presumed normal autoregulation) completed this randomized, double-masked, crossover trial. After a 4-week wash-out period, patients received spironolactone 25 mg o...... correlated with diabetes duration (R = 0.67, P hypertension, baseline BP, GFR, HbA1c or to changes in BP. CONCLUSION: Spironolactone did not change the overall ability to autoregulate GFR in 16 hypertensive type 1 diabetic patients with normoalbuminuria. Our data...

  4. Ginger pharmacopuncture improves cognitive impairment and oxidative stress following cerebral ischemia.

    Science.gov (United States)

    Jittiwat, Jinatta; Wattanathorn, Jintanaporn

    2012-12-01

    Recent findings have demonstrated that acupuncture and ginger can each improve memory impairment following cerebral ischemia. We hypothesized that ginger pharmacopuncture, a combination of these two treatments, could increase the beneficial effects. Due to the limitation of supporting evidence, we aimed to determine whether ginger pharmacopuncture could improve cognitive function and oxidative stress following cerebral ischemia. Male Wistar rats were induced by right middle cerebral artery occlusion (Rt. MCAO) and subjected to either acupuncture or ginger pharmacopuncture once daily over a period of 14 days after Rt. MCAO. Cognitive function was determined every 7 days, using escape latency and retention time as indices, and the oxidative stress status of the rats was determined at the end of the study. Rats subjected either to acupuncture or to ginger pharmacopuncture at GV20 demonstrated enhanced spatial memory, and the activities of catalase and glutathione peroxidase in both cerebral cortex and hippocampus were improved. Elevation of superoxide dismutase activity was observed only in the hippocampus. Cognitive enhancement was observed sooner with ginger pharmacopuncture than with acupuncture. The cognitive enhancing effect of acupuncture and ginger pharmacopuncture is likely to be at least partially attributable to decreased oxidative stress. However, other mechanisms may also be involved, and this requires further study.

  5. Disentangling How the Brain is "Wired" in Cortical (Cerebral) Visual Impairment.

    Science.gov (United States)

    Merabet, Lotfi B; Mayer, D Luisa; Bauer, Corinna M; Wright, Darick; Kran, Barry S

    2017-05-01

    Cortical (cerebral) visual impairment (CVI) results from perinatal injury to visual processing structures and pathways of the brain and is the most common cause of severe visual impairment or blindness in children in developed countries. Children with CVI display a wide range of visual deficits including decreased visual acuity, impaired visual field function, as well as impairments in higher-order visual processing and attention. Together, these visual impairments can dramatically influence a child's development and well-being. Given the complex neurologic underpinnings of this condition, CVI is often undiagnosed by eye care practitioners. Furthermore, the neurophysiological basis of CVI in relation to observed visual processing deficits remains poorly understood. Here, we present some of the challenges associated with the clinical assessment and management of individuals with CVI. We discuss how advances in brain imaging are likely to help uncover the underlying neurophysiology of this condition. In particular, we demonstrate how structural and functional neuroimaging approaches can help gain insight into abnormalities of white matter connectivity and cortical activation patterns, respectively. Establishing a connection between how changes within the brain relate to visual impairments in CVI will be important for developing effective rehabilitative and education strategies for individuals living with this condition. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Early treatment of minocycline alleviates white matter and cognitive impairments after chronic cerebral hypoperfusion.

    Science.gov (United States)

    Ma, Jing; Zhang, Jing; Hou, Wei Wei; Wu, Xiao Hua; Liao, Ru Jia; Chen, Ying; Wang, Zhe; Zhang, Xiang Nan; Zhang, Li San; Zhou, Yu Dong; Chen, Zhong; Hu, Wei Wei

    2015-01-01

    Subcortical ischemic vascular dementia (SIVD) caused by chronic cerebral hypoperfusion develops with progressive white matter and cognitive impairments, yet no effective therapy is available. We investigated the temporal effects of minocycline on an experimental SIVD exerted by right unilateral common carotid arteries occlusion (rUCCAO). Minocycline treated at the early stage (day 0-3), but not the late stage after rUCCAO (day 4-32) alleviated the white matter and cognitive impairments, and promoted remyelination. The actions of minocycline may not involve the inhibition of microglia activation, based on the effects after the application of a microglial activation inhibitor, macrophage migration inhibitory factor, and co-treatment with lipopolysaccharides. Furthermore, minocycline treatment at the early stage promoted the proliferation of oligodendrocyte progenitor cells (OPCs) in subventricular zone, increased OPC number and alleviated apoptosis of mature oligodendrocytes in white matter. In vitro, minocycline promoted OPC proliferation and increased the percentage of OPCs in S and G2/M phases. We provided direct evidence that early treatment is critical for minocycline to alleviate white matter and cognitive impairments after chronic cerebral hypoperfusion, which may be due to its robust effects on OPC proliferation and mature oligodendrocyte loss. So, early therapeutic time window may be crucial for its application in SIVD.

  7. Should we add visual acuity ratios to referral criteria for potential cerebral visual impairment?

    Science.gov (United States)

    van der Zee, Ymie J; Stiers, Peter; Evenhuis, Heleen M

    To determine whether the assessment of visual acuity ratios might improve the referral of children with (sub)normal visual acuity but at risk of cerebral visual impairment. In an exploratory study, we assessed visual acuity, crowding ratio and the ratios between grating acuity (Teller Acuity Cards-II) and optotype acuity (Cambridge Crowding Cards) in 60 typically developing school children (mean age 5y8m±1y1m), 21 children with ocular abnormalities only (5y7m±1y9m) and 26 children with (suspected) brain damage (5y7m±1y11m). Sensitivities and specificities were calculated for targets and controls from the perspective of different groups of diagnosticians: youth health care professionals (target: children with any visual abnormalities), ophthalmologists and low vision experts (target: children at risk of cerebral visual impairment). For youth health care professionals subnormal visual acuity had the best sensitivity (76%) and specificity (70%). For ophthalmologists and low vision experts the crowding ratio had the best sensitivity (67%) and specificity (79 and 86%). Youth health care professionals best continue applying subnormal visual acuity for screening, whereas ophthalmologists and low vision experts best add the crowding ratio to their routine diagnostics, to distinguish children at risk of visual impairment in the context of brain damage from children with ocular pathology only. Copyright © 2016 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

  8. Effects of cerebrolysin on moderate cognitive impairments in cerebral vascular insufficiency (a clinical-electrophysiological study).

    Science.gov (United States)

    Damulin, I V; Koberskaya, N N; Mkhitaryan, E A

    2008-07-01

    The efficacy of treatment with cerebrolysin was studied in 40 patients with cerebral vascular insufficiency. Cerebrolysin (20 daily i.v. infusions of 10 ml in 200 ml of physiological saline) was found to be an effective means of treating this group of patients. Courses of cerebrolysin treatment decreased the severity of memory and attention impairments, improving the overall cognitive status of the patients. Clinical observations and neuropsychological testing were supported by electrophysiological results, in terms of the P300 cognitive evoked potential. The effects of treatment at the doses used here were delayed and were seen three months after completion of treatment.

  9. Peritoneal dialysis impairs nitric oxide homeostasis and may predispose infants with low systolic blood pressure to cerebral ischemia.

    Science.gov (United States)

    Carlström, Mattias; Cananau, Carmen; Checa, Antonio; Wide, Katarina; Sartz, Lisa; Svensson, Anders; Wheelock, Craig E; Westphal, Susanne; Békássy, Zivile; Bárány, Peter; Lundberg, Jon O; Hansson, Sverker; Weitzberg, Eddie; Krmar, Rafael T

    2016-08-31

    Infants on chronic peritoneal dialysis (PD) have an increased risk of developing neurological morbidities; however, the underlying biological mechanisms are poorly understood. In this clinical study, we investigated whether PD-mediated impairment of nitric oxide (NO) bioavailability and signaling, in patients with persistently low systolic blood pressure (SBP), can explain the occurrence of cerebral ischemia. Repeated blood pressure measurements, serial neuroimaging studies, and investigations of systemic nitrate and nitrite levels, as well as NO signaling, were performed in ten pediatric patients on PD. We consistently observed the loss of both inorganic nitrate (-17 ± 3%, P low SBP developed ischemic cerebral complications. Our data suggests that PD impairs NO homeostasis and predisposes infants with persistently low SBP to cerebral ischemia. These findings improve current understanding of the pathogenesis of infantile cerebral ischemia induced by PD and may lead to the new treatment strategies to reduce neurological morbidities. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Impact of cerebral visual impairments on motor skills : implications for developmental coordination disorders.

    Directory of Open Access Journals (Sweden)

    Sylvie Chokron

    2016-10-01

    Full Text Available Cerebral visual impairment (CVI has become the primary cause of visual impairment and blindness in children in industrialized countries. Its prevalence has increased sharply, due to increased survival rates of children who sustain severe neurological conditions during the perinatal period. Improved diagnosis has probably contributed to this increase. As in adults, the nature and severity of CVI in children relate to the cause, location and extent of damage to the brain. In the present paper, we define CVI and how this impacts on visual function. We then define DCD and discuss the link between CVI and DCD. The neuroanatomical correlates and aetiologies of DCD are also presented in relationship with CVI as well as the consequences of perinatal asphyxia and preterm birth on the occurrence and nature of DCD and CVI. This paper underlines why there are both clinical and theoretical reasons to disentangle CVI and DCD, and to categorise the features with more precision. In order to offer the most appropriate rehabilitation, we propose a systematic and rapid evaluation of visual function in at-risk children who have survived preterm birth or perinatal asphyxia whether or not they have been diagnosed with cerebral palsy or DCD.

  11. Impact of Cerebral Visual Impairments on Motor Skills: Implications for Developmental Coordination Disorders

    Science.gov (United States)

    Chokron, Sylvie; Dutton, Gordon N.

    2016-01-01

    Cerebral visual impairment (CVI) has become the primary cause of visual impairment and blindness in children in industrialized countries. Its prevalence has increased sharply, due to increased survival rates of children who sustain severe neurological conditions during the perinatal period. Improved diagnosis has probably contributed to this increase. As in adults, the nature and severity of CVI in children relate to the cause, location and extent of damage to the brain. In the present paper, we define CVI and how this impacts on visual function. We then define developmental coordination disorder (DCD) and discuss the link between CVI and DCD. The neuroanatomical correlates and aetiologies of DCD are also presented in relationship with CVI as well as the consequences of perinatal asphyxia (PA) and preterm birth on the occurrence and nature of DCD and CVI. This paper underlines why there are both clinical and theoretical reasons to disentangle CVI and DCD, and to categorize the features with more precision. In order to offer the most appropriate rehabilitation, we propose a systematic and rapid evaluation of visual function in at-risk children who have survived preterm birth or PA whether or not they have been diagnosed with cerebral palsy or DCD. PMID:27757087

  12. Impact of Cerebral Visual Impairments on Motor Skills: Implications for Developmental Coordination Disorders.

    Science.gov (United States)

    Chokron, Sylvie; Dutton, Gordon N

    2016-01-01

    Cerebral visual impairment (CVI) has become the primary cause of visual impairment and blindness in children in industrialized countries. Its prevalence has increased sharply, due to increased survival rates of children who sustain severe neurological conditions during the perinatal period. Improved diagnosis has probably contributed to this increase. As in adults, the nature and severity of CVI in children relate to the cause, location and extent of damage to the brain. In the present paper, we define CVI and how this impacts on visual function. We then define developmental coordination disorder (DCD) and discuss the link between CVI and DCD. The neuroanatomical correlates and aetiologies of DCD are also presented in relationship with CVI as well as the consequences of perinatal asphyxia (PA) and preterm birth on the occurrence and nature of DCD and CVI. This paper underlines why there are both clinical and theoretical reasons to disentangle CVI and DCD, and to categorize the features with more precision. In order to offer the most appropriate rehabilitation, we propose a systematic and rapid evaluation of visual function in at-risk children who have survived preterm birth or PA whether or not they have been diagnosed with cerebral palsy or DCD.

  13. Visual-perceptual impairment in children with cerebral palsy: a systematic review.

    Science.gov (United States)

    Ego, Anne; Lidzba, Karen; Brovedani, Paola; Belmonti, Vittorio; Gonzalez-Monge, Sibylle; Boudia, Baya; Ritz, Annie; Cans, Christine

    2015-04-01

    Visual perception is one of the cognitive functions often impaired in children with cerebral palsy (CP). The aim of this systematic literature review was to assess the frequency of visual-perceptual impairment (VPI) and its relationship with patient characteristics. Eligible studies were relevant papers assessing visual perception with five common standardized assessment instruments in children with CP published from January 1990 to August 2011. Of the 84 studies selected, 15 were retained. In children with CP, the proportion of VPI ranged from 40% to 50% and the mean visual perception quotient from 70 to 90. None of the studies reported a significant influence of CP subtype, IQ level, side of motor impairment, neuro-ophthalmological outcomes, or seizures. The severity of neuroradiological lesions seemed associated with VPI. The influence of prematurity was controversial, but a lower gestational age was more often associated with lower visual motor skills than with decreased visual-perceptual abilities. The impairment of visual perception in children with CP should be considered a core disorder within the CP syndrome. Further research, including a more systematic approach to neuropsychological testing, is needed to explore the specific impact of CP subgroups and of neuroradiological features on visual-perceptual development. © 2015 The Authors. Developmental Medicine & Child Neurology © 2015 Mac Keith Press.

  14. T-type Ca(2+) channels and Autoregulation of Local Blood Flow

    DEFF Research Database (Denmark)

    Jensen, Lars Jørn; Nielsen, Morten Schak; Salomonsson, Max

    2017-01-01

    different vascular beds. Lack of specific pharmacological inhibitors has been a huge challenge in the field. Now the research has been strengthened by genetically modified models such as mice lacking expression of T-type voltage gated Ca(2+) channels (CaV3.1 and CaV3.2). Hopefully, these new tools will help......L-type voltage gated Ca(2+) channels are considered to be the primary source of calcium influx during the myogenic response. However, many vascular beds also express T-type voltage gated Ca(2+) channels. Recent studies suggest that these channels may also play a role in autoregulation. At low...... pressures (40-80 mm Hg) T-type channels affect myogenic responses in cerebral and mesenteric vascular beds. T-type channels also seem to be involved in skeletal muscle autoregulation. This review discusses the expression and role of T-type voltage gated Ca(2+) channels in the autoregulation of several...

  15. Neonatal cerebral lesions predict 2-year neurodevelopmental impairment in children treated with laser surgery for twin-twin transfusion syndrome.

    Science.gov (United States)

    Chmait, Ramen H; Chon, Andrew H; Schrager, Sheree M; Llanes, Arlyn; Hamilton, Anita H; Vanderbilt, Douglas L

    2017-09-06

    The objective of this study is to assess whether postnatally detected cerebral abnormalities are predictive of neurodevelopmental impairment (NDI) in survivors of twin-twin transfusion syndrome (TTTS) that underwent laser surgery. Ninety-nine children treated for TTTS had neurodevelopmental assessment at age 2-years (±6 weeks). 'High-risk survivors' had cerebral imaging in the neonatal period. 'High-risk survivors' were defined as (1) delivered at Battelle Developmental Inventory 2nd edition (BDI-2) score <70, cerebral palsy, blindness, and/or deafness. Multilevel logistic regression with robust standard errors was used to evaluate associations between cerebral lesions and NDI. Fifty-six children were 'high-risk survivors' and had neonatal cerebral imaging. Ten twins (18%) had at least one cerebral lesion, including grade 1-2 intraventricular hemorrhage (8), cystic periventricular leukomalacia (2), ventriculomegaly (1), and bilateral subependymal cyst (1). The risk of NDI in the 'high-risk survivors' was 7% (4/56) compared with 0% (0/43) in the remaining group. Among 'high-risk survivors', cerebral lesions were a significant risk factor for NDI (OR = 19.28, p < .001). Among 'high-risk survivors' of TTTS treated with laser surgery, cerebral lesions identified on neonatal imaging were associated with NDI at 2-years.

  16. Association between arterial stiffness, cerebral small vessel disease and cognitive impairment: a systematic review and meta-analysis

    Science.gov (United States)

    van Sloten, Thomas T; Protogerou, Athanase D; Henry, Ronald MA; Schram, Miranda T; Launer, Lenore J; Stehouwer, Coen DA

    2017-01-01

    Arterial stiffness may be a cause of cerebral small vessel disease and cognitive impairment. We therefore performed a systematic review and meta-analysis of studies on the association between stiffness, cerebral small vessel disease and cognitive impairment. For the associations between stiffness (i.e. carotid-femoral pulse wave velocity (cfPWV), brachial-ankle PWV (baPWV), carotid stiffness and pulse pressure) on the one hand and cerebral small vessel disease and cognitive impairment on the other, we identified 23 (n=15,666/22 cross-sectional/3 longitudinal) and 41 studies (n=57,671/30 cross-sectional/15 longitudinal), respectively. Pooled analyses of cross-sectional studies showed that greater stiffness was associated with markers of cerebral small vessel disease with odds ratios, per +1 SD, of 1.29 to 1.32 (P<.001). Studies on cognitive impairment could not be pooled due to large heterogeneity. Some (but not all) studies showed an association between greater stiffness and cognitive impairment, and the strength of this association was relatively weak. The present study supports the hypothesis that greater arterial stiffness is a contributor to microvascular brain disease. PMID:25827412

  17. Association of brain amyloid-β with cerebral perfusion and structure in Alzheimer's disease and mild cognitive impairment.

    Science.gov (United States)

    Mattsson, Niklas; Tosun, Duygu; Insel, Philip S; Simonson, Alix; Jack, Clifford R; Beckett, Laurel A; Donohue, Michael; Jagust, William; Schuff, Norbert; Weiner, Michael W

    2014-05-01

    Patients with Alzheimer's disease have reduced cerebral blood flow measured by arterial spin labelling magnetic resonance imaging, but it is unclear how this is related to amyloid-β pathology. Using 182 subjects from the Alzheimer's Disease Neuroimaging Initiative we tested associations of amyloid-β with regional cerebral blood flow in healthy controls (n = 51), early (n = 66) and late (n = 41) mild cognitive impairment, and Alzheimer's disease with dementia (n = 24). Based on the theory that Alzheimer's disease starts with amyloid-β accumulation and progresses with symptoms and secondary pathologies in different trajectories, we tested if cerebral blood flow differed between amyloid-β-negative controls and -positive subjects in different diagnostic groups, and if amyloid-β had different associations with cerebral blood flow and grey matter volume. Global amyloid-β load was measured by florbetapir positron emission tomography, and regional blood flow and volume were measured in eight a priori defined regions of interest. Cerebral blood flow was reduced in patients with dementia in most brain regions. Higher amyloid-β load was related to lower cerebral blood flow in several regions, independent of diagnostic group. When comparing amyloid-β-positive subjects with -negative controls, we found reductions of cerebral blood flow in several diagnostic groups, including in precuneus, entorhinal cortex and hippocampus (dementia), inferior parietal cortex (late mild cognitive impairment and dementia), and inferior temporal cortex (early and late mild cognitive impairment and dementia). The associations of amyloid-β with cerebral blood flow and volume differed across the disease spectrum, with high amyloid-β being associated with greater cerebral blood flow reduction in controls and greater volume reduction in late mild cognitive impairment and dementia. In addition to disease stage, amyloid-β pathology affects cerebral blood flow across the span from controls to

  18. The link between impaired theory of mind and executive function in children with cerebral palsy.

    Science.gov (United States)

    Li, Xiaoming; Wang, Kai; Wu, Jianxian; Hong, Yongfeng; Zhao, Jingpu; Feng, Xiaojun; Xu, Mei; Wang, Min; Ndasauka, Yamikani; Zhang, Xiaochu

    2014-07-01

    The aim of the study was to explore the relationship between theory of mind (ToM) deficits and executive function (EF) impairments in children with cerebral palsy (CP), 42 CP with children and 42 typically developing (TD) children, acting as controls, were assessed on the tasks of ToM (false belief and faux pas) and EF (inhibition, updating and shifting). Results showed that CP children had deficits both in ToM and EF tasks. The correlation analyses showed that two EF components (inhibition and updating) were strongly related to false belief and faux pas in both two groups. We also found correlation between shifting and false belief and faux pas. However, this correlation was only found in TD children and not in children with CP. These findings suggest that children with CP lag behind TD children in both ToM and EF. Further, the results reveal, interestingly, that ToM deficits in CP children might be related to their inhibition and updating impairments, but not to shifting impairments.

  19. Defective motion processing in children with cerebral visual impairment due to periventricular white matter damage.

    Science.gov (United States)

    Weinstein, Joel M; Gilmore, Rick O; Shaikh, Sumera M; Kunselman, Allen R; Trescher, William V; Tashima, Lauren M; Boltz, Marianne E; McAuliffe, Matthew B; Cheung, Albert; Fesi, Jeremy D

    2012-07-01

    We sought to characterize visual motion processing in children with cerebral visual impairment (CVI) due to periventricular white matter damage caused by either hydrocephalus (eight individuals) or periventricular leukomalacia (PVL) associated with prematurity (11 individuals). Using steady-state visually evoked potentials (ssVEP), we measured cortical activity related to motion processing for two distinct types of visual stimuli: 'local' motion patterns thought to activate mainly primary visual cortex (V1), and 'global' or coherent patterns thought to activate higher cortical visual association areas (V3, V5, etc.). We studied three groups of children: (1) 19 children with CVI (mean age 9y 6mo [SD 3y 8mo]; 9 male; 10 female); (2) 40 neurologically and visually normal comparison children (mean age 9y 6mo [SD 3y 1mo]; 18 male; 22 female); and (3) because strabismus and amblyopia are common in children with CVI, a group of 41 children without neurological problems who had visual deficits due to amblyopia and/or strabismus (mean age 7y 8mo [SD 2y 8mo]; 28 male; 13 female). We found that the processing of global as opposed to local motion was preferentially impaired in individuals with CVI, especially for slower target velocities (p=0.028). Motion processing is impaired in children with CVI. ssVEP may provide useful and objective information about the development of higher visual function in children at risk for CVI. © The Authors. Journal compilation © Mac Keith Press 2011.

  20. Cerebrospinal fluid profiles with increasing number of cerebral microbleeds in a continuum of cognitive impairment.

    Science.gov (United States)

    Shams, Sara; Granberg, Tobias; Martola, Juha; Li, Xiaozhen; Shams, Mana; Fereshtehnejad, Seyed-Mohammad; Cavallin, Lena; Aspelin, Peter; Kristoffersen-Wiberg, Maria; Wahlund, Lars-Olof

    2016-03-01

    Cerebral microbleeds (CMBs) are hypothesised to have an important yet unknown role in the dementia disease pathology. In this study we analysed increasing number of CMBs and their independent associations with routine cerebrospinal fluid (CSF) biomarkers in a continuum of cognitive impairment. A total of 1039 patients undergoing dementia investigation were analysed and underwent lumbar puncture, and an MRI scan. CSF samples were analysed for amyloid β (Aβ) 42, total tau (T-tau), tau phosphorylated at threonine 18 (P-tau) and CSF/serum albumin ratios. Increasing number of CMBs were independently associated with low Aβ42 levels, in the whole cohort, Alzheimer's disease and mild cognitive impairment (p CMBs (p CMBs when compared to zero CMBs, but did not change in the rest of the cohort. White matter hyperintensities were associated with low Aβ42 in the whole cohort and Alzheimer's disease (p CMBs in cognitive impairment, and there is an accumulative effect with increasing number of CMBs. © The Author(s) 2015.

  1. Intensive blood pressure control affects cerebral blood flow in type 2 diabetes mellitus patients

    DEFF Research Database (Denmark)

    Kim, Yu-Sok; Davis, Shyrin C A T; Truijen, Jasper;

    2011-01-01

    Type 2 diabetes mellitus is associated with microvascular complications, hypertension, and impaired dynamic cerebral autoregulation. Intensive blood pressure (BP) control in hypertensive type 2 diabetic patients reduces their risk of stroke but may affect cerebral perfusion. Systemic hemodynamic...... variables and transcranial Doppler-determined cerebral blood flow velocity (CBFV), cerebral CO2 responsiveness, and cognitive function were determined after 3 and 6 months of intensive BP control in 17 type 2 diabetic patients with microvascular complications (T2DM+), in 18 diabetic patients without (T2DM......-) microvascular complications, and in 16 nondiabetic hypertensive patients. Cerebrovascular reserve capacity was lower in T2DM+ versus T2DM- and nondiabetic hypertensive patients (4.6±1.1 versus 6.0±1.6 [P

  2. Distribution of cerebral microbleeds determines their association with impaired kidney function.

    Science.gov (United States)

    Song, Tae-Jin; Kim, Jinkwon; Lee, Hye Sun; Nam, Chung Mo; Nam, Hyo Suk; Kim, Young Dae; Heo, Ji Hoe

    2014-07-01

    Cerebral microbleeds (CMBs) are associated with various pathologies of the cerebral small vessels according to their distribution (i.e., cerebral amyloid angiopathy or hypertensive angiopathy). We investigated the association between CMB location and kidney function in acute ischemic stroke patients. We enrolled 1669 consecutive patients with acute ischemic stroke who underwent gradient-recalled echo brain magnetic resonance imaging. Kidney function was determined using the estimated glomerular filtration rate (eGFR). CMBs were classified into strictly lobar, strictly nonlobar (i.e., only deep or infratentorial), and a combination of both lobar and nonlobar. Multinomial logistic regression analyses were used to determine the factors associated with the existence of CMBs according to their location. The patients were aged 66±12 years (mean±standard deviation), and 61.9% (1033/1669) of them were male. CMBs were found in 27.0% (452/1669) of the patients. The stroke subtypes of small-artery occlusion and cardioembolism occurred more frequently in those with strictly nonlobar CMBs (10.8%) and strictly lobar CMBs (48.8%), respectively. The mean eGFR was lower in the strictly nonlobar CMBs group (72±28 mL/min/1.73 m(2)) and the both lobar and nonlobar CMBs group (72±25 mL/min/1.73 m(2)) than in the no-CMBs group (86±29 mL/min/1.73 m(2)). Multivariate multinomial logistic regression revealed that eGFR CMBs (odds ratio=2.63, p=0.001). Impaired kidney function is associated with strictly nonlobar CMBs. Our findings indicate that the distribution of CMBs should be considered when evaluating their relationships or prognoses.

  3. Cerebral Visual Impairment: Which Perceptive Visual Dysfunctions Can Be Expected in Children with Brain Damage? A Systematic Review

    Science.gov (United States)

    Boot, F. H.; Pel, J. J. M.; van der Steen, J.; Evenhuis, H. M.

    2010-01-01

    The current definition of Cerebral Visual Impairment (CVI) includes all visual dysfunctions caused by damage to, or malfunctioning of, the retrochiasmatic visual pathways in the absence of damage to the anterior visual pathways or any major ocular disease. CVI is diagnosed by exclusion and the existence of many different causes and symptoms make…

  4. Cerebral Damage May Be the Primary Risk Factor for Visual Impairment in Preschool Children Born Extremely Premature

    DEFF Research Database (Denmark)

    Slidsborg, Carina; Bangsgaard, Regitze; Fledelius, Hans Callø;

    2012-01-01

    OBJECTIVES To investigate the importance of cerebral damage and retinopathy of prematurity (ROP) for visual impairment in preschool children born extremely premature and to determine the primary risk factor of the two. METHODS A clinical follow-up study of a Danish national cohort of children bor...

  5. Cerebral Visual Impairment: Which Perceptive Visual Dysfunctions Can Be Expected in Children with Brain Damage? A Systematic Review

    Science.gov (United States)

    Boot, F. H.; Pel, J. J. M.; van der Steen, J.; Evenhuis, H. M.

    2010-01-01

    The current definition of Cerebral Visual Impairment (CVI) includes all visual dysfunctions caused by damage to, or malfunctioning of, the retrochiasmatic visual pathways in the absence of damage to the anterior visual pathways or any major ocular disease. CVI is diagnosed by exclusion and the existence of many different causes and symptoms make…

  6. IL-33 receptor ST2 regulates the cognitive impairments associated with experimental cerebral malaria.

    Science.gov (United States)

    Reverchon, Flora; Mortaud, Stéphane; Sivoyon, Maëliss; Maillet, Isabelle; Laugeray, Anthony; Palomo, Jennifer; Montécot, Céline; Herzine, Améziane; Meme, Sandra; Meme, William; Erard, François; Ryffel, Bernhard; Menuet, Arnaud; Quesniaux, Valérie F J

    2017-04-01

    Cerebral malaria (CM) is associated with a high mortality rate and long-term neurocognitive impairment in survivors. The murine model of experimental cerebral malaria (ECM) induced by Plasmodium berghei ANKA (PbA)-infection reproduces several of these features. We reported recently increased levels of IL-33 protein in brain undergoing ECM and the involvement of IL-33/ST2 pathway in ECM development. Here we show that PbA-infection induced early short term and spatial memory defects, prior to blood brain barrier (BBB) disruption, in wild-type mice, while ST2-deficient mice did not develop cognitive defects. PbA-induced neuroinflammation was reduced in ST2-deficient mice with low Ifng, Tnfa, Il1b, Il6, CXCL9, CXCL10 and Cd8a expression, associated with an absence of neurogenesis defects in hippocampus. PbA-infection triggered a dramatic increase of IL-33 expression by oligodendrocytes, through ST2 pathway. In vitro, IL-33/ST2 pathway induced microglia expression of IL-1β which in turn stimulated IL-33 expression by oligodendrocytes. These results highlight the IL-33/ST2 pathway ability to orchestrate microglia and oligodendrocytes responses at an early stage of PbA-infection, with an amplification loop between IL-1β and IL-33, responsible for an exacerbated neuroinflammation context and associated neurological and cognitive defects.

  7. Setting up of a cerebral visual impairment clinic for children: Challenges and future developments.

    Science.gov (United States)

    Philip, Swetha Sara

    2017-01-01

    The aim of this study is to describe the setting up of a cerebral visual impairment (CVI) clinic in a tertiary care hospital in South India and to describe the spectrum of cases seen. The CVI clinic, set up in February 2011, receives interdisciplinary input from a core team involving a pediatrician, neurologist, psychiatrist, occupational therapist, pediatric ophthalmologist, and an optometrist. All children, cerebral palsy (CP), learning disability, autism, neurodegenerative diseases, and brain trauma are referred to the clinic for functional vision assessment and opinion for further management. One thousand four hundred and seventy-eight patients were seen in the CVI clinic from February 2011 to September 2015. Eighty-five percent of the patients were from different parts of India. In the clinic, 61% had CP, 28% had seizure disorders, autism was seen in 9.5%, and learning disability, neurodegenerative conditions, and brain injury together constituted 1.5%. Most of the children (45%) had moderate CP. Forty percent of CVI was due to birth asphyxia, but about 20% did not have any known cause for CVI. Seventy percent of patients, who came back for follow-up, were carrying out the habilitation strategies suggested. Average attendance of over 300 new patients a year suggests a definite need for CVI clinics in the country. These children need specialized care to handle their complex needs. Although difficult to coordinate, an interdisciplinary team including the support groups and voluntary organizations is needed to facilitate the successful implementation of such specialized service.

  8. Cerebral and blood correlates of reduced functional connectivity in mild cognitive impairment.

    Science.gov (United States)

    Gonzalez-Escamilla, Gabriel; Atienza, Mercedes; Garcia-Solis, David; Cantero, Jose L

    2016-01-01

    Growing evidence suggests that decreased functional connectivity in cortical networks precedes clinical stages of Alzheimer's disease (AD), although our knowledge about cerebral and biological correlates of this phenomenon is limited. To shed light on this issue, we have investigated whether resting-state oscillatory connectivity patterns in healthy older (HO) and amnestic mild cognitive impairment (aMCI) subjects are related to anatomical grey matter (GM) and functional (2-[18F]fluoro-2-deoxy-D-glucose (FDG)-PET) changes of neuroelectric sources of alpha rhythms, and/or to changes in plasma amyloid-beta (Aβ) and serum lipid levels, blood markers tied to AD pathogenesis and aging-related cognitive decline. We found that aMCI subjects showed decreased levels of cortical connectivity, reduced FDG-PET intake of the precuneus, and GM atrophy of the thalamus, together with higher levels of Aβ and apolipoprotein B (ApoB) compared to HO. Interestingly, levels of high-density lipoprotein (HDL) cholesterol were positively correlated with the strength of neural-phase coupling in aMCI subjects, and increased triglycerides accompanied bilateral GM loss in the precuneus of aMCI subjects. Together, these findings provide peripheral blood correlates of reduced resting-state cortical connectivity in aMCI, supported by anatomo-functional changes in cerebral sources of alpha rhythms. This framework constitutes an integrated approach to assess functional changes in cortical networks through neuroimaging and peripheral blood markers during early stages of neurodegeneration.

  9. Gross motor function in children with spastic Cerebral Palsy and Cerebral Visual Impairment: A comparison between outcomes of the original and the Cerebral Visual Impairment adapted Gross Motor Function Measure-88 (GMFM-88-CVI).

    Science.gov (United States)

    Salavati, M; Rameckers, E A A; Waninge, A; Krijnen, W P; Steenbergen, B; van der Schans, C P

    2017-01-01

    To investigate whether the adapted version of the Gross Motor Function Measure-88 (GMFM-88) for children with Cerebral Palsy (CP) and Cerebral Visual Impairment (CVI) results in higher scores. This is most likely to be a reflection of their gross motor function, however it may be the result of a better comprehension of the instruction of the adapted version. The scores of the original and adapted GMFM-88 were compared in the same group of children (n=21 boys and n=16 girls), mean (SD) age 113 (30) months with CP and CVI, within a time span of two weeks. A paediatric physical therapist familiar with the child assessed both tests in random order. The GMFCS level, mental development and age at testing were also collected. The Wilcoxon signed-rank test was used to compare two different measurements (the original and adapted GMFM-88) on a single sample, (the same child with CP and CVI; pvisual problems. On the basis of these findings, we recommend using the adapted GMFM-88 to measure gross motor functioning in children with CP and CVI. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. [The effectiveness of dynamic proprioceptive correction in patients with cerebral palsy with cognitive impairment].

    Science.gov (United States)

    Nemkova, S A; Maslova, O I

    2013-01-01

    One hundred and sixty-seven patients with cerebral palsy (CP), aged 11-16 years, with spastic diplegia (n=87) and hemiparetic forms (n=80), with subgroups of mental retardation (MR) or intellectual delay (ID) have been studied. Standard treatment and application of a method of dynamic proprioceptive correction (MDPC) in the complex rehabilitation with the use of a medical and loading Adeli suit were used. Cognitive deficit in patients was characterized by the relative integrity of short-term nonverbal memory and marked impairment of verbal memory, verbal and nonverbal intellect. CP patients with intellectual delay demonstrated the predominant impairment of verbal functions. CP patients with mental retardation have the deficiency of both verbal and non-verbal cognitive functions. An individual profile of brain functional asymmetry in patients with CP was more lateralized than in healthy peers that can represent a mechanism for irregular development of cognitive functions in CP. Implementing the MDPC into comprehensive rehabilitation promotes the improvement of postural regulation and cognitive functions in children with CP compared to traditional methods of treatment. This is accompanied by the changes in functioning of the associative brain areas and hemispheric interaction.

  11. Acute ischemic cerebral attack

    OpenAIRE

    Franco-Garcia Samir; Barreiro-Pinto Belis

    2010-01-01

    The decrease of the cerebral blood flow below the threshold of autoregulation led to changes of cerebral ischemia and necrosis that traduce in signs and symtoms of focal neurologic dysfunction called acute cerebrovascular symdrome (ACS) or stroke. Two big groups according to its etiology are included in this category the hemorragic that constitue a 20% and the ischemic a 80% of cases. Great interest has wom the ischemic ACS because of its high social burden, being the third cause of no violen...

  12. Loss of autoregulation of blood flow in subcutaneous tissue in juvenile diabetes

    DEFF Research Database (Denmark)

    Henriksen, O; Kastrup, J; Parving, H H;

    1984-01-01

    and retinopathy. The blood flow remained constant in all normal subjects, when the arterial perfusion pressure was varied between 70 and 150 mm Hg. All diabetics had impaired or reduced autoregulation of the subcutaneous blood flow. The blood flow increased and decreased almost linearly with the changes...... in arterial perfusion pressure. The mechanism underlying the defect autoregulation of blood flow in diabetics is uncertain; possibilities include structural changes of the arterioles and/or alterations of local metabolic factors.......The autoregulation of blood flow in subcutaneous tissue was investigated at the level of the lateral malleolus by the local 133Xenon washout technique. We have investigated eight long-term insulin-dependent diabetics and seven healthy controls. All diabetics had moderate diabetic nephropathy...

  13. Characteristics and dynamics of cognitive impairment in patients with primary and recurrent cerebral ischemic hemispheric stroke

    Directory of Open Access Journals (Sweden)

    A. A. Kozyolkin

    2014-08-01

    Full Text Available Acute cerebrovascular disease is a global medical and social problem of the modern angioneurology, occupying leading positions in the structure of morbidity and mortality among adult population of the world. Ischemic stroke – is one of the most common pathology. Today this disease took out the world pandemic. More than 16 million new cases of cerebral infarction recorded in the world each year and it “kills” about 7 million of people. About 111,953 cases of cerebral stroke were registered in 2013 in Ukraine. Cognitive impairment, t hat significantly disrupt daily activities and life of the patient, is one of the most significant post-stroke complications that have social, medical and biological significance. Aim. The purpose of this investigation was to study features and dynamics of cognitive impairments in patients with primary and recurrent cerebral hemispheric ischemic stroke (CHIS in the acute stage of the disease. Materials and methods. To achieve the aim, and the decision of tasks in the clinic of nervous diseases Zaporozhye State Medical University (supervisor - Doctor of Medicine, Professor Kozelkin A. based on the department of acute cerebrovascular disease were performed comparative, prospective cohort study, which included comprehensive clinical and paraclinical examinations of 41 patients (26 men and 15 women aged 45 to 85 years (mean age 66,4 ± 1,4 years with acute left-hemispheric (2 patients and right - hemispheric (39 patients CHIS . First up was a group of 28 patients (19 men and 9 women, mean age 65,6 ± 1,6 years, who suffered from primary CHIS. The second group consisted of 13 patients (7 men and 6 women, mean age 68,1 ± 2,5 years with recurrent CHIS. The groups were matched by age, sex, localization of the lesion and the initial level of neurological deficit. All patients underwent physical examination, neurological examination. Dynamic clinical neurological examination assessing the severity of stroke was conducted

  14. Time-varying modeling of cerebral hemodynamics.

    Science.gov (United States)

    Marmarelis, Vasilis Z; Shin, Dae C; Orme, Melissa; Rong Zhang

    2014-03-01

    The scientific and clinical importance of cerebral hemodynamics has generated considerable interest in their quantitative understanding via computational modeling. In particular, two aspects of cerebral hemodynamics, cerebral flow autoregulation (CFA) and CO2 vasomotor reactivity (CVR), have attracted much attention because they are implicated in many important clinical conditions and pathologies (orthostatic intolerance, syncope, hypertension, stroke, vascular dementia, mild cognitive impairment, Alzheimer's disease, and other neurodegenerative diseases with cerebrovascular components). Both CFA and CVR are dynamic physiological processes by which cerebral blood flow is regulated in response to fluctuations in cerebral perfusion pressure and blood CO2 tension. Several modeling studies to date have analyzed beat-to-beat hemodynamic data in order to advance our quantitative understanding of CFA-CVR dynamics. A confounding factor in these studies is the fact that the dynamics of the CFA-CVR processes appear to vary with time (i.e., changes in cerebrovascular characteristics) due to neural, endocrine, and metabolic effects. This paper seeks to address this issue by tracking the changes in linear time-invariant models obtained from short successive segments of data from ten healthy human subjects. The results suggest that systemic variations exist but have stationary statistics and, therefore, the use of time-invariant modeling yields "time-averaged models" of physiological and clinical utility.

  15. Clinical effects of Xingnao Kaiqiao acupuncture on neurological impairment following cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    Jie Xiong; Lina Ning; Jinling Bian; Jun Li; Junfeng Xu; Zhilong Zhang; Jiakui Guo; Yadong Li; Xuemin Shi

    2008-01-01

    effective power:Basic recovery: equal to or more than 81%; significant improvement: 56% to 81% (including 56%); Improvement: between 36% to 56% (including 36%); Slight Improvement: 11% to 36% (including 11%); No change: less than 11%; Aggravation (including death): negative value. Total effective rate was computed at the same time.MAIN OUTCOME MEASURES: The total effective rate and amelioration of neurological impairment of the patients after treatment.RESULTS: All 120 patients with cerebral infarction were included in the final analysis, without deletion.① Comparison of the total effective rate: the total effective rate of group Ⅰ, group Ⅱ, group Ⅲ, and group Ⅳ was 97%, 93%, 93%, and 67%, respectively. There were significant differences of interclass synthetic curative effects (χ2 = 36.351 7, P < 0.01). ② Amelioration of neurological impairment: A decreased neurological impairment score was observed in group I on day 7, 14, and 21 after Xingnao Kaiqiao therapy. The differences between group IV and the remaining three groups were significant (P < 0.05).CONCLUSION: Xingnao Kaiqiao therapy is helpful for amelioration of neurological impairment in patients during the acute stage cerebral infarction.

  16. Current management and treatment of cerebral vasospasm complicating SAH.

    Science.gov (United States)

    Kühn, Anna Luisa; Balami, Joyce Saleh; Grunwald, Iris Quasar

    2013-03-01

    Cerebral vasospasm is a common and serious complication of aneurysmal subarachnoid haemorrhage. Despite the improvements in treatment of aneurysmal subarachnoid haemorrhage (aSAH), cerebral vasospasm complicating aSAH has remained the main cause of morbidity and mortality. Subarachnoid haemorrhage (SAH)-induced vasospasm is a complex entity caused by vasculopathy, impaired autoregulation, and hypovolaemia, causing a regional reduction of cerebral brain perfusion which can then induce ischaemia. Cerebral vasospasm can present either asymptomatically detected only radiologically or symptomatically (delayed ischaemic neurologic deficit). The various diagnostic approaches include the use of transcranial doppler, digital subtraction angiography and multimodal computed tomography (CT) and magnetic resonance (MR) techniques. Although digital subtraction angiography is usually the gold standard for the diagnosis of cerebral vasospam, transcranial doppler is commonly the first-screening method for the detection of cerebral vasospam. The treatment of subarachnoid haemorrhage -induced vasospasm include the use of both medical and endovascular therapy. The aim of this review is to discuss the various current therapeutic options and future perspective measures for reducing cerebral vasospasm induced stroke after SAH.

  17. Ocular Blood Flow Autoregulation Mechanisms and Methods

    OpenAIRE

    Xue Luo; Yu-meng Shen; Meng-nan Jiang; Xiang-feng Lou; Yin Shen

    2015-01-01

    The main function of ocular blood flow is to supply sufficient oxygen and nutrients to the eye. Local blood vessels resistance regulates overall blood distribution to the eye and can vary rapidly over time depending on ocular need. Under normal conditions, the relation between blood flow and perfusion pressure in the eye is autoregulated. Basically, autoregulation is a capacity to maintain a relatively constant level of blood flow in the presence of changes in ocular perfusion pressure and va...

  18. Setting up of a cerebral visual impairment clinic for children: Challenges and future developments

    Science.gov (United States)

    Philip, Swetha Sara

    2017-01-01

    Aim: The aim of this study is to describe the setting up of a cerebral visual impairment (CVI) clinic in a tertiary care hospital in South India and to describe the spectrum of cases seen. Materials and Methods: The CVI clinic, set up in February 2011, receives interdisciplinary input from a core team involving a pediatrician, neurologist, psychiatrist, occupational therapist, pediatric ophthalmologist, and an optometrist. All children, <18 years of age, with cerebral palsy (CP), learning disability, autism, neurodegenerative diseases, and brain trauma are referred to the clinic for functional vision assessment and opinion for further management. Results: One thousand four hundred and seventy-eight patients were seen in the CVI clinic from February 2011 to September 2015. Eighty-five percent of the patients were from different parts of India. In the clinic, 61% had CP, 28% had seizure disorders, autism was seen in 9.5%, and learning disability, neurodegenerative conditions, and brain injury together constituted 1.5%. Most of the children (45%) had moderate CP. Forty percent of CVI was due to birth asphyxia, but about 20% did not have any known cause for CVI. Seventy percent of patients, who came back for follow-up, were carrying out the habilitation strategies suggested. Conclusions: Average attendance of over 300 new patients a year suggests a definite need for CVI clinics in the country. These children need specialized care to handle their complex needs. Although difficult to coordinate, an interdisciplinary team including the support groups and voluntary organizations is needed to facilitate the successful implementation of such specialized service. PMID:28300737

  19. Pressure Autoregulation Measurement Techniques in Adult TBI, Part II: A Scoping Review of Continuous Methods.

    Science.gov (United States)

    Zeiler, Frederick Adam; Donnelly, Joseph; Calviello, Leanne; Smieleweski, Peter; Menon, David; Czosnyka, Marek

    2017-07-12

    To perform systematically a scoping review of the literature on commonly described continuous autoregulation measurement techniques in adult TBI. The goal was to provide an overview of methodology and comprehensive reference library of the available literature for each technique. Five separate small systematic reviews were conducted for each of the continuous techniques: pressure reactivity index (PRx), laser Doppler flowmetry (LDF), near infrared spectroscopy (NIRS) techniques, brain tissue oxygen tension (PbtO2), and thermal diffusion (TD) techniques. Articles from MEDLINE, BIOSIS, EMBASE, Global Health, Scopus, Cochrane Library (inception to December 2016) and reference lists of relevant articles were searched. A two-tier filter of references was conducted. The literature base identified from the individual searches was limited, except for PRx. The total number of articles utilizing each of the 5 searched techniques for continuous autoregulation in adult TBI were: PRx (28), LDF (4), NIRS (9), PbtO2 (10), and TD (8). All continuous techniques described in adult TBI are based on moving correlation coefficients. The premise behind the calculation of these moving correlation coefficients focuses on the impact of slow fluctuations in either MAP or CPP on some indirect measure of CBF, such as: intracranial pressure (ICP), LDF, NIRS signals, PbtO2 or TD CBF. The thought is the correlation between a hemodynamic driving factor, such as MAP or CPP, and a surrogate for CBF or cerebral perfusion sheds insight on the state of cerebral autoregulation. Both PRx and NIRS indices were validated experimentally against 'golden standard' static autoregulatory curve (Lassen curve) at least around lower threshold of autoregulation. PRx has the largest literature base supporting the association with patient outcome. Various methods of continuous autoregulation assessment are described within the adult TBI literature. Many studies exist on these various indices, suggesting an

  20. Antecedents and neuroimaging patterns in cerebral palsy with epilepsy and cognitive impairment: a population-based study in children born at term.

    Science.gov (United States)

    Ahlin, Kristina; Jacobsson, Bo; Nilsson, Staffan; Himmelmann, Kate

    2017-07-01

    Antecedents of accompanying impairments in cerebral palsy and their relation to neuroimaging patterns need to be explored. A population-based study of 309 children with cerebral palsy born at term between 1983 and 1994. Prepartum, intrapartum, and postpartum variables previously studied as antecedents of cerebral palsy type and motor severity were analyzed in children with cerebral palsy and cognitive impairment and/or epilepsy, and in children with cerebral palsy without these accompanying impairments. Neuroimaging patterns and their relation to identified antecedents were analyzed. Data were retrieved from the cerebral palsy register of western Sweden, and from obstetric and neonatal records. Children with cerebral palsy and accompanying impairments more often had low birthweight (kg) (odds ratio 0.5, 95% confidence interval 0.3-0.8), brain maldevelopment known at birth (p = 0.007, odds ratio ∞) and neonatal infection (odds ratio 5.4, 95% confidence interval 1.04-28.4). Moreover, neuroimaging patterns of maldevelopment (odds ratio 7.2, 95% confidence interval 2.9-17.2), cortical/subcortical lesions (odds ratio 5.3, 95% confidence interval 2.3-12.2) and basal ganglia lesions (odds ratio 7.6, 95% confidence interval 1.4-41.3) were more common, wheras white matter injury was found significantly less often (odds ratio 0.2, 95% confidence interval 0.1-0.5). In most children with maldevelopment, the intrapartum and postpartum periods were uneventful (p Cerebral maldevelopment was associated with prepartum antecedents, whereas subcortical/cortical and basal ganglia lesions were associated with intrapartum and postpartum antecedents. No additional factor other than those related to motor impairment was associated with epilepsy and cognitive impairment in cerebral palsy. Timing of antecedents deemed important for the development of cerebral palsy with accompanying impairments were supported by neuroimaging patterns. © 2017 Nordic Federation of Societies of Obstetrics

  1. Characteristic patterns of cerebral blood perfusion and cognitive impairment in patients with Parkinsons disease

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Y. J.; Park, M. J.; Cha, J. G.; Kim, S. H.; Kim, J. W.; Kang, D. Y. [Dong-A University College of medicine, Pusan (Korea, Republic of)

    2005-07-01

    Parkinsons disease (PD) is a neurodegenerative disorder that represents cognitive impairment as well as motor symptoms. Even in the early stages of PD, cognitive alterations can be demonstrated by careful neuropsychological test. The purposes of this study are to investigate the pattern of cognitive impairment and the regional cerebral blood flow (rCBF) using Tc-99m HMPAO SPECT in patients with PD. One hundred and twenty two patients with PD and 35 control subjects participated in this study. Patients with PD who had dementia clinically or K-MMSE score below 25 points or with severe motor dysfunction to interfere with the tests were also excluded. They were all matched for age (61{+-}10 vs 61{+-}8), education periods (8.8{+-}4.9 vs 8.8{+-}4.5), and K-MMSE score (27{+-}1.6 vs 27{+-}1.5). All subjects were evaluated using the Seoul Neuropsychological Screening Battery (SNSB) and Tc-99m HMPAO SPECT with SPM software to measure rCBF. Patients with PD performed worse in digit span backward, Rey Complex Figure Test, visual memory, semantic fluency, stroop test, and alternating hand movement test(p<0.05) compared with control group. On SNSB test, 100 patients (82.0%) showed some abnormalities. Eighty-six patients (70.5%) showed frontal dysfunction, 47 (38.5%) memory impairment, 33 (27.0%) language dysfunction, 25 (20.5%) attention deficit and 22 (18.3%) visuospatial dysfunction in the order of frequency. Eight patients with PD showed single memory domain MCI and 28 single non-memory domain MCI (20 frontal dysfunction). Multiple domain MCI was found in 64 patients with PD. SPM analysis of the SPECT image revealed multiple perfusion deficit in the both frontal, temporal, both limbic lobes, Lt. parietal and Lt. Putamen. It is concluded that abnormalities of cognitive function be detected very commonly in patients with PD. MCI in PD patients is most frequently involved in the item of frontal lobe function. SPECT image might be helpful to explain cognitive impairment in some

  2. Changes of cerebral blood flow and cerebral autoregulation during propofol or sevoflurane anaesthesia in patients undergoing gynecologic laparoscopic surgery%七氟醚或异丙酚对妇科腹腔镜手术病人脑血流量和脑血管自身调节能力的影响

    Institute of Scientific and Technical Information of China (English)

    田复波; 黄绍强; 梁伟民

    2009-01-01

    Objective To observe the effects of propofol or sevoflurane combined with remifentanil on cerebral blood flow (CBF) and cerebral autoregulation in patients undergoing gynecologic laparoscopic surgery. Methods Forty patients were randomly divided into two groups: the propofol group (group P, n=20) and the sevoflurane group (group S, n=20). Anaesthesia was induced with target-controlled infusion (TCI) of propofol and remifentanil in group P, with an inhaled induction of sevoflurane and TCI of remifentanil in group S, respectively. The depth of anesthesia was regulated according to bispectral index (BIS). The pressure of end-tidal carbon dioxide (P_(ET)CO_2) was kept at 35-40 mmHg by mechanical ventilation. The mean arterial pressure (MAP), heart rate (HR), pressure of arterial carbon dioxide (PaCO_2), P_(ET)CO_2, time-averaged peak flow velocity (TAP) and the transient hyperaemic response ratio (THRR) were recorded at 7 different time points: supine position (T_1) and supine lithotomy position before induction (T_2), the instant and 5 min after tracheal intubation (T_3,T_4), the instant and 15 min after abdominal CO_2 insufflation and trendelenburg-lithotomy position (T_5,T_6), and 10 min after the deflation abdomen (T_7), respectively. Results Compared with the baseline values at T_1, TAP was not significantly changed at T_2, T_5, or T_6 in group P, but was markedly decreased at T_3, T_4 and T_7. TAP in group S only decreased at T_4 and T_7, while it was much higher than that in group P at T_3. In group S, THRR was markedly lowered at T_3 compared with that at T_1; but in group P, it showed a significant increase at T_3. Conclusions Combined with remifentanil, propofol decreased CBF, but has no effect on the brain self-regulation. When inhaled in high concentrations, sevoflurane significantly reduces the brain self-regulation. Intraoperation pneumoperitoneum and postural factor significantly increase CBF, playing a stronger role than the narcotic drugs in clinical

  3. Structural network connectivity impairment and depressive symptoms in cerebral small vessel disease.

    Science.gov (United States)

    Xie, Xiaofeng; Shi, Yulu; Zhang, Junjian

    2017-10-01

    Cerebral small vessel disease (SVD) can disrupt mood regulation circuits and cause depressive symptoms which may occur prior to onset of other symptoms. However, the topological network alterations in SVD with depressive symptoms remained unclear. We aim to investigate how these changes in structural network were related to depressive symptoms in SVD. We recruited 20 SVD with depressive symptoms (SVD+D), 20 SVD without depressive symptoms (SVD-D) and 16 healthy control (HC) individuals. Graph theory and diffusion tensor imaging (DTI) were applied to construct a structural network. We compared networks between groups, and examined the relationships between network properties, conventional measures of MRI, and depressive symptoms. The structural network was significantly disrupted in global and regional levels in both SVD groups. SVD+D group showed more severe impairment of global network efficiency, and lower nodal efficiency and less connections within multiple regions like hippocampus, amygdala and several cortical structures. The disruption of network connectivity was associated with depressive symptoms and MRI measures of SVD, however, no mediation effect of network efficiency was detected between MRI measures and depressive symptoms. The relatively small sample size and lower spatial resolution of DTI-based network limited our power of investigation. The brain structural network is significantly disrupted in SVD+D and the impairment is related to severity of vascular damages and depressive symptoms. The study provides evidence for the role of structural network damage in SVD-related depressive symptoms and might be a potential novel disease marker for SVD and comorbid depression. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. A study on cognitive impairment and gray matter volume abnormalities in silent cerebral infarction patients

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Wei; Wei, Xiaofeng; Li, Mengxiong [The First Affiliated Hospital of Yangtze University, Biomedical Engineering Laboratory, Jingzhou, Hubei (China); Jiang, Xun [Renmin Hospital of Wuhan University, Biomedical Engineering Laboratory, Wuhan, Hubei (China); Li, Shanshan [JingZhou City Central Blood Bank, Jingzhou, Hubei (China)

    2015-08-15

    The relationship between silent cerebral infarction (SCI) and the integrity of cognitive function is unknown. We intended to investigate whether cognitive impairment is associated with gray matter volume (GMV) in the SCI patients. Sixty-two patients with SCI and 62 age- and gender-matched healthy controls (HC) were evaluated with P300 test, Montreal Cognitive Assessment (MoCA) test, Hamilton Anxiety Scale (HAMA), and Hamilton Depression Scale (HDRS). Whole brain high-resolution T1-weighted images were processed with SPM12b software and analyzed by voxel-based morphometry (VBM). Correlation analysis was performed between the GMV and the scores of MoCA Scale, P300 latency, P300 amplitude, HAMA, HDRS, age, and educational level. The brains of the SCI patients have a significant reduction in GMV in the left superior and inferior frontal gyrus, left superior temporal gyrus, right middle temporal gyrus, and bilateral hippocampus gyrus (p < 0.01, FDR correction). No significant increase of GMV was detected. The GMV of their frontal and temporal lobes is positively correlated with the score of MoCA scale and P300 amplitude (r ≥ 0.62, p < 0.01). The GMV of frontal, temporal, and hippocampus is negatively correlated with P300 latency (r ≤ -0.71, p < 0.05). No significant correlation between the GMV of abnormal brain regions and another two clinical characteristics was found. SCI patients have impaired cognitive function and reduced GMV compared to the HC subjects. The neuropathological basis of such cognitive deficits in SCI patients might be a reduced GMV. (orig.)

  5. Impaired visually guided weight-shifting ability in children with cerebral palsy.

    Science.gov (United States)

    Ballaz, Laurent; Robert, Maxime; Parent, Audrey; Prince, François; Lemay, Martin

    2014-09-01

    The ability to control voluntary weight shifting is crucial in many functional tasks. To our knowledge, weight shifting ability in response to a visual stimulus has never been evaluated in children with cerebral palsy (CP). The aim of the study was (1) to propose a new method to assess visually guided medio-lateral (M/L) weight shifting ability and (2) to compare weight-shifting ability in children with CP and typically developing (TD) children. Ten children with spastic diplegic CP (Gross Motor Function Classification System level I and II; age 7-12 years) and 10 TD age-matched children were tested. Participants played with the skiing game on the Wii Fit game console. Center of pressure (COP) displacements, trunk and lower-limb movements were recorded during the last virtual slalom. Maximal isometric lower limb strength and postural control during quiet standing were also assessed. Lower-limb muscle strength was reduced in children with CP compared to TD children and postural control during quiet standing was impaired in children with CP. As expected, the skiing game mainly resulted in M/L COP displacements. Children with CP showed lower M/L COP range and velocity as compared to TD children but larger trunk movements. Trunk and lower extremity movements were less in phase in children with CP compared to TD children. Commercially available active video games can be used to assess visually guided weight shifting ability. Children with spastic diplegic CP showed impaired visually guided weight shifting which can be explained by non-optimal coordination of postural movement and reduced muscular strength.

  6. The influence of decompressive craniectomy for major stroke on early cerebral perfusion.

    Science.gov (United States)

    Slotty, Philipp Jörg; Kamp, Marcel Alexander; Beez, Thomas; Beenen, Henrieke; Steiger, Hans-Jakob; Turowski, Bernd; Hänggi, Daniel

    2015-07-01

    Multiple trials have shown improved survival and functional outcome in patients treated with decompressive craniectomy (DC) for brain swelling following major stroke. It has been assumed that decompression induces an improvement in cerebral perfusion. This observational study directly measured cerebral perfusion before and after decompression. Sixteen patients were prospectively examined with perfusion CT within 6 hours prior to surgery and 12 hours after surgery. Preoperative and postoperative perfusion measurements were compared and correlated. Following DC there was a significant increase in cerebral blood flow in all measured territories and additionally an increase in cerebral blood volume in the penumbra (p = 0.03). These changes spread as far as the contralateral hemisphere. No significant changes in mean transit time or Tmax (time-to-peak residue function) were observed. The presurgical perfusion abnormalities likely reflected local pressure-induced hypoperfusion with impaired autoregulation. The improvement in perfusion after decompression implied an increase in perfusion pressure, likely linked to partial restoration of autoregulation. The increase in perfusion that was observed might partially be responsible for improved clinical outcome following decompressive surgery for major stroke. The predictive value of perfusion CT on outcome needs to be evaluated in larger trials.

  7. Changes in cerebral blood oxygenation induced by active standing test in children with POTS and NMS.

    Science.gov (United States)

    Endo, Ayumi; Fujita, Yukihiko; Fuchigami, Tatsuo; Takahashi, Shori; Mugishima, Hideo; Skatani, Kaoru

    2014-01-01

    Orthostatic dysregulation (OD) has been classified into subtypes by heart rate and blood pressure; however, the hemodynamics of brains have not yet been revealed. Therefore, we investigated changes in cerebral blood flow and oxygenation during an active standing test to clarify the pathophysiology of two subtypes: postural tachycardia syndrome (POTS) and neurally mediated syncope (NMS). We studied 31 children (15 boys, 16 girls; mean age, 14.0 ± 1.7 years) who presented with OD at the Department of Pediatrics and Child Health, Nihon University School of Medicine between 2009 and 2011. OD was diagnosed using the Japanese clinical guidelines for juvenile orthostatic dysregulation. After a 10-min resting period in the supine position, patients were asked to quickly stand up and keep upright for 10 min. Cerebral blood flow and cerebral oxygenation were measured using transcranial Doppler sonography and near-infrared spectroscopy. POTS showed a significant decrease of oxy-Hb and resistance index (RI), suggesting transient ischemia with maintainable cerebral autoregulation. NMS showed a decrease of oxy-Hb and an increase of RI, suggesting ischemia and impairment of autoregulation.

  8. Asiaticoside attenuates memory impairment induced by transient cerebral ischemia-reperfusion in mice through anti-inflammatory mechanism.

    Science.gov (United States)

    Chen, She; Yin, Zhu-Jun; Jiang, Chen; Ma, Zhan-Qiang; Fu, Qiang; Qu, Rong; Ma, Shi-Ping

    2014-07-01

    Asiaticoside (AS) is isolated from Centella asiatica (L.) which has been using for a long time as a memory enhancing drug in India. This study was to investigate the effects of AS on memory impairment and inflammatory cytokines expression induced by transient cerebral ischemia and reperfusion in mice, as well as the potential signaling pathway. Transient bilateral common carotid artery occlusion (tBCCAO) induced severe memory deficits in mice according to the Morris water maze task and the step-down passive avoidance test. Meanwhile the microglial activation and the gene expression of inflammatory cytokines including interleukin (IL)-1β, interleukin (IL)-6 and tumor necrosis factor (TNF)-α were increased in the hippocampus of the mice with cerebral ischemia and reperfusion. Oral administration of AS (40 and 60 mg/kg, once per day, started the day after surgery and lasted for 7 days) significantly ameliorated the memory impairment and the inflammation. Moreover, AS (20, 40 and 60 mg/kg) markedly reduced the microglial overactivation and the phosphorylation of p38 MAPK in hippocampus compared with the transient cerebral ischemia and reperfusion group. These results suggested that AS showed the neuroprotective effect against transient cerebral ischemia and reperfusion in mice, and this effect might be associated with the anti-inflammation effect of AS via inhibiting overactivation of p38 MAPK pathway.

  9. Betaine reverses the memory impairments in a chronic cerebral hypoperfusion rat model.

    Science.gov (United States)

    Nie, Chunjie; Nie, Huijuan; Zhao, Yin; Wu, Jianzhao; Zhang, Xiaojian

    2016-02-26

    Vascular dementia (VaD) is the second reason for the cognitive decline in aged people, but the effective therapy is still missing. The chronic cerebral hypoperfusion (CCH) had been widely found in VaD patients and is thought to be the key reason for cognitive impairment. Betaine is a natural product that had been implicated in many biological processes and had been used for the therapy of some neurodegenerative disease, such as Alzheimer's disease. In this study, we reported that betaine treatment could rescue the memory deficits induced by two-vessel occlusion (2-VO), a widely used CCH rat model. Betaine also restored the expression of PSD93, PSD95 and MAP2 to preserve the synaptic functions. Furthermore, betaine could reduce the oxidative stress by suppressing the MDA and ROS and enhancing the SOD and GSH. Overall, betaine treatment is able to rescue the memory deficits in CCH rats, which provide an experimental basis for the therapy of VaD.

  10. Walking-induced muscle fatigue impairs postural control in adolescents with unilateral spastic cerebral palsy.

    Science.gov (United States)

    Vitiello, Damien; Pochon, Ludmilla; Malatesta, Davide; Girard, Olivier; Newman, Christopher J; Degache, Francis

    2016-01-01

    Fatigue is likely to be an important limiting factor in adolescents with spastic cerebral palsy (CP). To determine the effects of walking-induced fatigue on postural control adjustments in adolescents with unilateral CP and their typically developing (TD) peers. Ten adolescents with CP (14.2 ± 1.7 yr) and 10 age-, weight- and height-matched TD adolescents (14.1 ± 1.9 yr) walked for 15 min on a treadmill at their preferred walking speed. Before and after this task, voluntary strength capacity of knee extensors (MVC) and postural control were evaluated in 3 conditions: eyes open (EO), eyes closed (EC) and with dual cognitive task (EODT). After walking, MVC decreased significantly in CP (-11%, P<0.05) but not in TD. The CoP area was only significantly increased in CP (90%, 34% and 60% for EO, EC and EODT conditions, respectively). The CoP length was significantly increased in the EO condition in CP and TD (20% and 21%) and was significantly increased in the EODT condition by 18% in CP only. Unlike TD adolescents, treadmill walking for 15 min at their preferred speed lead to significant knee extensor strength losses and impairments in postural control in adolescents with unilateral spastic CP. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. [Lower limb vein thrombosis in dynamics of acute impairments of cerebral circulation].

    Science.gov (United States)

    Kuntsevich, G I; Maksimova, M Iu; Popova, L A; Riabinkina, Iu V; Gnedovskaia, E V; Piradov, M A

    2012-01-01

    The present work was aimed at studying the state of the inferior vena cava system according to the findings of duplex scanning in dynamics of acute cerebral circulation impairments (ACCI). Amongst 100 patients with ACCI, lower limb vein deep thrombosis (LLVDT) was revealed in 57% of cases. The incidence of LLVDT in patients with intracerebral haemorrhage was higher than in those with ischaemic stroke, however there were no statistically significant differences between the type of ACCI (p=0.06) and subtypes of ischaemic stroke (atherothrombotic, ceardioembolic) (p = 0.68). The main risk factors for LLVDT are the presence of pronounced motion deficit in the extremities, induced by the underlying disease (p=0.02) and immobilization. In the overwhelming majority of patients (81%) thrombosis localized isolatedly in the crural veins. Ascending thrombosis and the development of a floating thrombus were represented mainly on the side of motility deficit in the extremities. We have confirmed a strong association between positive dynamics in the neurological status of patients and frequency of recanalization of thrombi (p=0.043). Ultrasonographic examination of lower limb veins in dynamics of ACCI is an important component of preventive and therapeutic process.

  12. Increased 20-HETE synthesis explains reduced cerebral blood flow but not impaired neurovascular coupling after cortical spreading depression in rat cerebral cortex

    DEFF Research Database (Denmark)

    Fordsmann, Jonas Christoffer; ko, Rebecca; Choi, Hyun B

    2013-01-01

    Cortical spreading depression (CSD) is associated with release of arachidonic acid (AA), impaired neurovascular coupling, and reduced cerebral blood flow (CBF), caused by cortical vasoconstriction. We tested the hypothesis that the released AA is metabolized by the cytochrome P450 enzyme to produce...... neurovascular coupling after CSD. These findings suggest that CSD-induced increments in 20-HETE cause the reduction in CBF after CSD, and that the attenuation of stimulation-induced CBF responses after CSD has a different mechanism. We suggest that blockade of 20-HETE synthesis may be clinically relevant...

  13. Combinatorial Gene Regulation Using Auto-Regulation

    Science.gov (United States)

    Hermsen, Rutger; Ursem, Bas; ten Wolde, Pieter Rein

    2010-01-01

    As many as 59% of the transcription factors in Escherichia coli regulate the transcription rate of their own genes. This suggests that auto-regulation has one or more important functions. Here, one possible function is studied. Often the transcription rate of an auto-regulator is also controlled by additional transcription factors. In these cases, the way the expression of the auto-regulator responds to changes in the concentrations of the “input” regulators (the response function) is obviously affected by the auto-regulation. We suggest that, conversely, auto-regulation may be used to optimize this response function. To test this hypothesis, we use an evolutionary algorithm and a chemical–physical model of transcription regulation to design model cis-regulatory constructs with predefined response functions. In these simulations, auto-regulation can evolve if this provides a functional benefit. When selecting for a series of elementary response functions—Boolean logic gates and linear responses—the cis-regulatory regions resulting from the simulations indeed often exploit auto-regulation. Surprisingly, the resulting constructs use auto-activation rather than auto-repression. Several design principles show up repeatedly in the simulation results. They demonstrate how auto-activation can be used to generate sharp, switch-like activation and repression circuits and how linearly decreasing response functions can be obtained. Auto-repression, on the other hand, resulted only when a high response speed or a suppression of intrinsic noise was also selected for. The results suggest that, while auto-repression may primarily be valuable to improve the dynamical properties of regulatory circuits, auto-activation is likely to evolve even when selection acts on the shape of response function only. PMID:20548950

  14. Effects of Blood Pressure Fluctuations on Cerebral Perfusion after Ischemic Stroke%血压波动对脑梗死后脑灌注的影响

    Institute of Scientific and Technical Information of China (English)

    聂志余; 靳令经

    2011-01-01

    Cerebral infarction affects both cerebral autoregulation and cerebral perfusion. This review article summarizes the published evidence of cerebral autoregulation impairment and cerebral blood flow alteration after cerebral infarction, including cerebrovascular small vessel disease leading to an impairment of vasoreactivity, blood flow velocities and cerebral blood flow associated positively with systemic blood pressure, perfusion declined on the infarcted side and lower blood pressure resulting in hypoperfusion in distal area of the narrowing main cerebral artery. The question should be thought by physicians about what is the 'best blood pressure range' in patients with cerebral infarction and it will be benefit for optimal recovery.%本文主要从脑血管的自动调节与自动调节受损、脑小血管病变可导致脑血管反应性受损、脑梗死患者脑血流速度、脑血流量与血压的相关性,脑梗死侧大脑半球脑灌注降低、低血压对脑主要动脉狭窄者可导致狭窄远端脑组织局部低灌注等几个方面来讨论脑梗死后血压的变化对脑血流速度、脑血流量的影响.给临床医生提出一个思考问题,在脑梗死的急性期把血压控制在多少才是最合适的水平,对患者的功能恢复最有益.

  15. OBSTRUCTIVE SLEEP APNEA: THE STATE OF CEREBRAL HEMODYNAMIC RESERVE

    Directory of Open Access Journals (Sweden)

    N. L. Kunelskaya

    2016-01-01

    Full Text Available Background: Individuals with obstructive  sleep apnea syndrome (OSAS have an increased risk of disabling disorders of the cardiovascular system, including  stroke.  The  mechanisms   of OSAS effects on cerebral blood flow and cerebral vascular autoregulation have not been clear enough. Aim: To study characteristics of cerebral blood flow in patients  with OSAS and the effect of CPAP therapy on cerebral hemodynamic reserve. Materials and  methods: One  hundred and  two  patients with various OSAS severity (61 male  and  41 female and  20 healthy  volunteers  participated in the study. We performed  ultrasound assessment of cerebral  blood  flow with functional  tests  and calculated  reactivity indices. Results: With more severe OSAS, no significant differences in cerebral vascular reactivity compared to the control group were  registered. However, there  was a trend  to some  decrease  in the  index of constriction  and dilation  in the  vertebral  arteries  and  the  basilar artery, as well as to its increase in the middle cerebral artery in severe and moderate OSAS. The index of vasomotor  reactivity of cerebral  arteries was significantly (р < 0.05 lower in patients with  severe  OSAS:  for vertebral  arteries,  up  to 38.9 ± 8.5 and for basilar artery, up to 36.8 ± 15.7, compared to  the  control  group  (52.1 ± 9.8 and 50.1 ± 11.2, respectively. In patients who initiated CPAP therapy, there were no changes  in velosity, resistance  and  reactivity parameters of cerebral vessels after 2 months. Conclusion: We were able to  confirm a significant  impairment  of cerebral vascular autoregulation  in patients  with severe OSAS, predominantly in the posterior circulatory region. CPAP-therapy of 2 months'  duration  did not lead to restoration  of cerebral hemodynamic reserve.

  16. Distribution of Cerebral Microbleeds Determines Their Association with Impaired Kidney Function

    OpenAIRE

    Song, Tae-Jin; Kim, Jinkwon; Lee, Hye Sun; Nam, Chung Mo; Nam, Hyo Suk; Kim, Young Dae; Heo, Ji Hoe

    2014-01-01

    Background and Purpose Cerebral microbleeds (CMBs) are associated with various pathologies of the cerebral small vessels according to their distribution (i.e., cerebral amyloid angiopathy or hypertensive angiopathy). We investigated the association between CMB location and kidney function in acute ischemic stroke patients. Methods We enrolled 1669 consecutive patients with acute ischemic stroke who underwent gradient-recalled echo brain magnetic resonance imaging. Kidney function was determin...

  17. Protein nitration impairs the myogenic tone of rat middle cerebral arteries in both ischemic and nonischemic hemispheres after ischemic stroke.

    Science.gov (United States)

    Coucha, Maha; Li, Weiguo; Johnson, Maribeth H; Fagan, Susan C; Ergul, Adviye

    2013-12-01

    The myogenic response is crucial for maintaining vascular resistance to achieve constant perfusion during pressure fluctuations. Reduced cerebral blood flow has been reported in ischemic and nonischemic hemispheres after stroke. Ischemia-reperfusion injury and the resulting oxidative stress impair myogenic responses in the ischemic hemisphere. Yet, the mechanism by which ischemia-reperfusion affects the nonischemic side is still undetermined. The goal of the present study was to determine the effect of ischemia-reperfusion injury on the myogenic reactivity of cerebral vessels from both hemispheres and whether protein nitration due to excess peroxynitrite production is the underlying mechanism of loss of tone. Male Wistar rats were subjected to sham operation or 30-min middle cerebral artery occlusion/45-min reperfusion. Rats were administered saline, the peroxynitrite decomposition catalyst 5,10,15,20-tetrakis(4-sulfonatophenyl)prophyrinato iron (III), or the nitration inhibitor epicatechin at reperfusion. Middle cerebral arteries isolated from another set of control rats were exposed to ex vivo oxygen-glucose deprivation with and without glycoprotein 91 tat (NADPH oxidase inhibitor) or N(ω)-nitro-l-arginine methyl ester. Myogenic tone and nitrotyrosine levels were determined. Ischemia-reperfusion injury impaired the myogenic tone of vessels in both hemispheres compared with the sham group (P nitration improved the myogenic tone of vessels from ischemic (P Nitration was significantly increased in both hemispheres versus the sham group and was normalized with epicatechin treatment. In conclusion, ischemia-reperfusion injury impairs vessel reactivity in both hemispheres via nitration. We suggest that sham operation rather than the nonischemic side should be used as a control in preclinical stroke studies.

  18. Patterns of 11C-PIB cerebral retention in mild cognitive impairment patients.

    Science.gov (United States)

    Banzo, I; Jiménez-Bonilla, J F; Martínez-Rodríguez, I; Quirce, R; de Arcocha-Torres, M; Bravo-Ferrer, Z; Lavado-Pérez, C; Sánchez-Juan, P; Rodríguez, E; Jiménez-Alonso, M; López-Defilló, J; Carril, J M

    2016-01-01

    To evaluate the patterns of cerebral cortical distribution of (11)C-PIB in patients with mild cognitive impairment (MCI). The study included 69 patients (37 male, age range 42-79 years) with MCI, sub-classified as 53 with amnestic-MCI (A-MCI), and 16 with non-amnestic-MCI (NA-MCI). Patients underwent (11)C-PIB PET/CT scan 60min after intravenous injection of the radiotracer. A visual analysis of the images was performed by 2 experienced physicians. (11)C-PIB-positive studies were considered when gray matter uptake was equal to or greater than white matter. According to the regions involved, (11)C-PIB-positive studies were classified into A-pattern (predominant retention in frontal, anterior cingulate, lateral temporal, and basal ganglia) and B-pattern (generalized retention). Thirty-nine of the 69 (56%) patients with MCI showed (11)C-PIB retention. Of the 53 A-MCI patients, 36 (68%) showed (11)C-PIB retention. Eleven out of 36 (30%) positive scans in A-MCI patients showed A-pattern, and 25 out of 36 (70%) patients had a B-pattern. Positive (11)C-PIB was observed in 3 out of 16 (19%) patients with NA-MCI. Regional distribution in these 3 patients showed A-pattern in 1, and B-pattern in 2 patients. Cortical retention of (11)C-PIB was more frequent in A-MCI than in NA-MCI patients, and also B-pattern than A-pattern in the (11)C-PIB positive group. The recognition of (11)C-PIB distribution patterns allows MCI patients to be classified, and the A-pattern may offer a therapeutic window for potential future treatments. Copyright © 2015 Elsevier España, S.L.U. and SEMNIM. All rights reserved.

  19. The Dyskinesia Impairment Scale: a new instrument to measure dystonia and choreoathetosis in dyskinetic cerebral palsy.

    Science.gov (United States)

    Monbaliu, Elegast; Ortibus, Els; De Cat, Jos; Dan, Bernard; Heyrman, Lieve; Prinzie, Peter; De Cock, Paul; Feys, Hilde

    2012-03-01

    The aim of this study was to examine the reliability and validity of the Dyskinesia Impairment Scale (DIS). The DIS consists of two subscales: dystonia and choreoathetosis. It measures both phenomena in dyskinetic cerebral palsy (CP). Twenty-five participants with dyskinetic CP (17 males; eight females; age range 5–22y; mean age 13y 6mo; SD 5y 4mo), recruited from special schools for children with motor disorders, were included. Exclusion criteria were changes in muscle relaxant medication within the previous 3 months, orthopaedic or neurosurgical interventions within the previous year, and spinal fusion. Interrater reliability was verified by two independent raters. For interrater reliability, intraclass correlation coefficients were assessed. Standard error of measurement, the minimal detectable difference, and Cronbach’s alpha for internal consistency were determined. For concurrent validity of the DIS dystonia subscale, the Barry–Albright Dystonia Scale was administered. The intraclass correlation coefficient for the total DIS score and the two subscales ranged between 0.91 and 0.98 for interrater reliability. The reliability of the choreoathetosis subscale was found to be higher than that of the dystonia subscale. The standard error of the measurement and minimal detectable difference values were adequate. Cronbach’s alpha values ranged from 0.89 to 0.93. Pearson’s correlation between the dystonia subscale and Barry–Albright Dystonia Scale was 0.84 (p<0.001). Good to excellent reliability and validity were found for the DIS. The DIS may be promising for increasing insights into the natural history of dyskinetic CP and evaluating interventions. Future research on the responsiveness of the DIS is warranted.

  20. A Meta-Analysis of Association between Cerebral Microbleeds and Cognitive Impairment

    Science.gov (United States)

    Wu, Rihan; Feng, Chao; Zhao, Yanxin; Jin, Ai-Ping; Fang, Min; Liu, Xueyuan

    2014-01-01

    Background The clinical effect of cerebral microbleeds (CMBs) on cognition has been receiving much research attention, but results are often inconsistent. Material/Methods We searched PubMed, Embase, Web of Science, and some Chinese electronic databases. A total of 15 studies were included. Results Patients with CMBs had higher incidence of cognitive dysfunction (OR 3.14; 95% CI 1.66–5.92) and lower scores of cognitive function (SMD was −0.36 [−0.55, −0.18] in the MMSE group and −0.65 [−0.99, −0.32] in the MoCA [Montreal Cognitive Assessment] group). The results also indicated that a higher number of CMB lesions led to more severe cognitive dysfunction (SMD was −2.41 [−5.04, −0.21] in the mild group and −2.75 [−3.50, −2.01] in the severe group). We also found that cognitive performance was significantly impaired when CMBs were located in deep (−0.4 [−0.69, −0.11]), lobar regions (−0.50 [−0.92, −0.09]), basal ganglia (−0.72 [−1.03, −0.41]), and thalamus brain regions (−0.65 [−0.98, −0.32]). Conclusions This meta-analysis showed that CMBs were associated with cognitive dysfunction according to higher number and different locations of CMBs. Future work should focus on long-term prognosis of continuing cognitive decline and specific treatments to reduce the formation of CMBs. PMID:25377475

  1. Inter-individual Relationships between Sympathetic Arterial Baroreflex Function and Cerebral Perfusion Control in Healthy Males

    OpenAIRE

    Trevor Witter; Yu-Chieh Tzeng; Terry O'Donnell; Jessica Kusel; Bridget Walker; Mary Berry; Chloe E. Taylor

    2017-01-01

    Maintenance of adequate cerebral perfusion during normal physiological challenges requires integration between cerebral blood flow (CBF) and systemic blood pressure control mechanisms. Previous studies have shown that cardiac baroreflex sensitivity (BRS) is inversely related to some measures of cerebral autoregulation. However, interactions between the sympathetic arterial baroreflex and cerebral perfusion control mechanisms have not been explored. To determine the nature and magnitude of the...

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

    CERN Document Server

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

    2016-01-01

    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 ...

  3. Cerebrovascular hemodynamics in patients with cerebral arteriosclerosis

    Institute of Scientific and Technical Information of China (English)

    Jianbo Yang; Changcong Cui; Chengbin Wu

    2011-01-01

    The present study observed hemodynamic changes in 26 patients with cerebral arteriosclerosis using a cerebral circulation dynamics detector and transcranial Doppler.In patients with cerebral arteriosclerosis the blood supply and flow rate in the bilateral carotid arteries and the blood flow rate in the anterior cerebral and middle cerebral arteries were similar to normal controls, but the cerebral vascular resistance, critical pressure and pulsatility index were increased, and cerebral arterial elasticity and cerebral blood flow autoregulation were decreased.Compared with the lesioned hemisphere of patients with cerebral infarction, the total blood supply and blood flow rate of patients with cerebral arteriosclerosis were higher.Compared with normal subjects, patients with cerebral arteriosclerosis exhibited cognitive disturbances, mainly in short-term memory, attention, abstract capability, and spatial and executive dysfunction.Results showed that cerebral arteriosclerosis does not directly affect the blood supply of a cerebral hemisphere, but affects cognitive function.The increased cerebral vascular resistance and reduced autoregulation of cerebral blood vessels may be important hemodynamic mechanisms of arteriosclerosis-induced cerebral infarction.

  4. Effects of Lacunar Infarctions on Cognitive Impairment in Patients with Cerebral Autosomal-Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy

    Science.gov (United States)

    Choi, Jay Chol; Kang, Sa-Yoon; Kang, Ji-Hoon; Na, Hae Ri; Park, Ji-Kang

    2011-01-01

    Background and Purpose Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited microangiopathy caused by mutations in the Notch3 gene. Although previous studies have shown an association between lacunar infarction and cognitive impairment, the relationship between MRI parameters and cognition remains unclear. In this study we investigated the influence of MRI parameters on cognitive impairment in CADASIL. Methods We applied a prospective protocol to 40 patients. MRI analysis included the normalized volume of white-matter hyperintensities (nWMHs), number of lacunes, and number of cerebral microbleeds. Cognition was assessed with the aid of psychometric tests [Mini-Mental State Examination (MMSE), Alzheimer's Disease Assessment Scale-cognition (ADAS-cog), Trail-Making Test, and Stroop interference (Stroop IF)]. Results A multivariate regression analysis revealed that the total number of lacunes influenced the performance in the MMSE, ADAS-cog, and Stroop IF, while nWMHs had a strong univariate association with ADAS-cog and Stroop IF scores. However, this association disappeared in the multivariate analysis. Conclusions These findings demonstrate that the number of lacunes is the main predictive factor of cognitive impairment in CADASIL. PMID:22259617

  5. Neurological impairment correlated to abnormal cerebral non-dominant transverse sinus drainage: a report of 12 cases

    Directory of Open Access Journals (Sweden)

    Bao-min LI

    2016-12-01

    Full Text Available Background Dominant venous sinus drainage of the brain is a common anatomic characteristic. Cortical venous partial retention that is due to slow non-dominant venous sinus drainage can increase local cerebral vein pressure, and cause related neurological impairment. This article is to investigate the diagnosis of local intracranial hypertension caused by abnormal non-dominant transverse sinus drainage and the effect of anticoagulation treatment. Methods From February 2008 to February 2016, there were 12 patients diagnosed as abnormal cerebral non-dominant transverse sinus drainage. Among these patients, 8 patients presented as dizziness and brain swelling; 2 presented as subarachnoid hemorrhage (SAH; one presented as cerebral cortex bleeding; 2 presented as blurred vision; 2 presented as ipsilateral pulsatile tinnitus; one presented as narcolepsy. Cerebrospinal fluid (CSF pressure of 2 patients were > 280 mm H2O. Nine patients were confirmed no abnormal characteristics by MRI. In DSA examination, 10 patients were confirmed non-dominant transverse sinus drainage and contrast agent retention on the left side, and 2 patients were confirmed on the right side. All patients were treated by anticoagulation, and 2 underwent stent implantation, 5 underwent thrombolysis through carotid artery. Results All patients were greatly improved after 7-day treatment. They were discharged within 2 weeks and were continuously treated by anticoagulation after discharge for one year. There was no recurrence or aggravation in all patients during the follow-up period ranging from 6 to 34 months. Two patients were confirmed less contrast agent retention by DSA after 6 months.  Conclusions Abnormal non-dominant transverse sinus drainage can increase local cerebral vein pressure, and presents non-specific clinical features such as dizziness, headache or tinnitus. Anticoagulation, thrombolysis or stent implantation can promote local cerebral venous drainage, relieve

  6. Diabetic microangiopathy: impact of impaired cerebral vasoreactivity and delayed angiogenesis after permanent middle cerebral artery occlusion on stroke damage and cerebral repair in mice.

    Science.gov (United States)

    Poittevin, Marine; Bonnin, Philippe; Pimpie, Cynthia; Rivière, Léa; Sebrié, Catherine; Dohan, Anthony; Pocard, Marc; Charriaut-Marlangue, Christiane; Kubis, Nathalie

    2015-03-01

    Diabetes increases the risk of stroke by three, increases related mortality, and delays recovery. We aimed to characterize functional and structural alterations in cerebral microvasculature before and after experimental cerebral ischemia in a mouse model of type 1 diabetes. We hypothesized that preexisting brain microvascular disease in patients with diabetes might partly explain increased stroke severity and impact on outcome. Diabetes was induced in 4-week-old C57Bl/6J mice by intraperitoneal injections of streptozotocin (60 mg/kg). After 8 weeks of diabetes, the vasoreactivity of the neurovascular network to CO2 was abolished and was not reversed by nitric oxide (NO) donor administration; endothelial NO synthase (eNOS) and neuronal NO synthase (nNOS) mRNA, phospho-eNOS protein, nNOS, and phospho-nNOS protein were significantly decreased; angiogenic and vessel maturation factors (vascular endothelial growth factor a [VEGFa], angiopoietin 1 (Ang1), Ang2, transforming growth factor-β [TGF-β], and platelet-derived growth factor-β [PDGF-β]) and blood-brain barrier (BBB) occludin and zona occludens 1 (ZO-1) expression were significantly decreased; and microvessel density was increased without changes in ultrastructural imaging. After permanent focal cerebral ischemia induction, infarct volume and neurological deficit were significantly increased at D1 and D7, and neuronal death (TUNEL+ / NeuN+ cells) and BBB permeability (extravasation of Evans blue) at D1. At D7, CD31+ / Ki67+ double-immunolabeled cells and VEGFa and Ang2 expression were significantly increased, indicating delayed angiogenesis. We show that cerebral microangiopathy thus partly explains stroke severity in diabetes.

  7. Etiology of impaired selective motor control: emerging evidence and its implications for research and treatment in cerebral palsy.

    Science.gov (United States)

    Cahill-Rowley, Katelyn; Rose, Jessica

    2014-06-01

    Selective motor control (SMC) impairment involves movement patterns dominated by flexor or extensor synergies that interfere with functional movements in children with cerebral palsy (CP). Emerging evidence on neural correlates of impaired SMC has important implications for etiology and for the treatment for children with CP. Early evidence on the microstructure of brain white matter assessed with diffusion tensor imaging in adult patients after stroke suggests that the rubrospinal tract may compensate for injury to the corticospinal tract. Furthermore, the observed changes on diffusion tensor imaging corresponded to the degree of SMC impairment. The rubrospinal tract may provide imperfect compensation in response to corticospinal tract injury, resulting in diminished SMC. Cortical mapping evidence in stroke patients indicates that loss of SMC is also associated with increased overlap of joint representation in the sensorimotor cortices. The severity of SMC impairment can be assessed with the recently developed Selective Control Assessment of the Lower Extremity, a validated observation-based measure designed for children with spastic CP. Recent advances in neuroimaging and assessment of SMC provide an opportunity to better understand the etiology and impact of impaired SMC, which may ultimately guide strategic treatment for children with CP. © 2013 Mac Keith Press.

  8. Reliability of the modified Paediatric Evaluation of Disability Inventory, Dutch version (PEDI-NL) for children with cerebral palsy and cerebral visual impairment.

    Science.gov (United States)

    Salavati, M; Waninge, A; Rameckers, E A A; de Blécourt, A C E; Krijnen, W P; Steenbergen, B; van der Schans, C P

    2015-02-01

    The aims of this study were to adapt the Paediatric Evaluation of Disability Inventory, Dutch version (PEDI-NL) for children with cerebral visual impairment (CVI) and cerebral palsy (CP) and determine test-retest and inter-respondent reliability. The Delphi method was used to gain consensus among twenty-one health experts familiar with CVI. Test-retest and inter-respondent reliability were assessed for parents and caregivers of 75 children (aged 50-144 months) with CP and CVI. The percentage identical scores of item scores were computed, as well as the interclass coefficients (ICC) and Cronbach's alphas of scale scores over the domains self-care, mobility, and social function. All experts agreed on the adaptation of the PEDI-NL for children with CVI. On item score, for the Functional Skills scale, mean percentage identical scores variations for test-retest reliability were 73-79 with Caregiver Assistance scale 73-81, and for inter-respondent reliability 21-76 with Caregiver Assistance scale 40-43. For all scales over all domains ICCs exceeded 0.87. For the domains self-care, mobility, and social function, the Functional Skills scale and the Caregiver Assistance scale have Cronbach's alpha above 0.88. The adapted PEDI-NL for children with CP and CVI is reliable and comparable to the original PEDI-NL. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Strategic lacunes and their relationship to cognitive impairment in cerebral small vessel disease

    Directory of Open Access Journals (Sweden)

    Philip Benjamin

    2014-01-01

    Conclusion: Lacunes are important predictors of cognitive impairment in SVD. We highlight the importance of spatial distribution, particularly of anteromedial thalamic lacunes which are associated with impaired information processing speed and may mediate cognitive impairment via disruption of connectivity to the prefrontal cortex.

  10. Effect of mild cognitive impairment and APOE genotype on resting cerebral blood flow and its association with cognition.

    Science.gov (United States)

    Wierenga, Christina E; Dev, Sheena I; Shin, David D; Clark, Lindsay R; Bangen, Katherine J; Jak, Amy J; Rissman, Robert A; Liu, Thomas T; Salmon, David P; Bondi, Mark W

    2012-08-01

    Using whole-brain pulsed arterial spin labeling magnetic resonance imaging, resting cerebral blood flow (CBF) was measured in 20 mild cognitive impairment (MCI; 11 ɛ3 and 9 ɛ4) and 40 demographically matched cognitively normal (CN; 27 ɛ3 and 13 ɛ4) participants. An interaction of apolipoprotein (APOE) genotype (ɛ3 and ɛ4) and cognitive status (CN and MCI) on quantified gray-matter CBF corrected for partial volume effects was found in the left parahippocampal and fusiform gyri (PHG/FG), right middle frontal gyrus, and left medial frontal gyrus. In the PHG/FG, CBF was elevated for CN ɛ4 carriers but decreased for MCI ɛ4 carriers. The opposite pattern was seen in frontal regions: CBF was decreased for CN ɛ4 carriers but increased for MCI ɛ4 carriers. Cerebral blood flow in the PHG/FG was positively correlated with verbal memory for CN ɛ4 adults (r=0.67, P=0.01). Cerebral blood flow in the left medial frontal gyrus was positively correlated with verbal memory for MCI ɛ4 adults (r=0.70, P=0.05). Findings support dynamic pathophysiologic processes in the brain associated with Alzheimer's disease risk and indicate that cognitive status and APOE genotype have interactive effects on CBF. Correlations between CBF and verbal memory suggest a differential neurovascular compensatory response in posterior and anterior cortices with cognitive decline in ɛ4 adults.

  11. Zingiber officinale Mitigates Brain Damage and Improves Memory Impairment in Focal Cerebral Ischemic Rat

    Directory of Open Access Journals (Sweden)

    Jintanaporn Wattanathorn

    2011-01-01

    Full Text Available Cerebral ischemia is known to produce brain damage and related behavioral deficits including memory. Recently, accumulating lines of evidence showed that dietary enrichment with nutritional antioxidants could reduce brain damage and improve cognitive function. In this study, possible protective effect of Zingiber officinale, a medicinal plant reputed for neuroprotective effect against oxidative stress-related brain damage, on brain damage and memory deficit induced by focal cerebral ischemia was elucidated. Male adult Wistar rats were administrated an alcoholic extract of ginger rhizome orally 14 days before and 21 days after the permanent occlusion of right middle cerebral artery (MCAO. Cognitive function assessment was performed at 7, 14, and 21 days after MCAO using the Morris water maze test. The brain infarct volume and density of neurons in hippocampus were also determined. Furthermore, the level of malondialdehyde (MDA, superoxide dismutase (SOD, catalase (CAT, and glutathione peroxidase (GSH-Px in cerebral cortex, striatum, and hippocampus was also quantified at the end of experiment. The results showed that cognitive function and neurons density in hippocampus of rats receiving ginger rhizome extract were improved while the brain infarct volume was decreased. The cognitive enhancing effect and neuroprotective effect occurred partly via the antioxidant activity of the extract. In conclusion, our study demonstrated the beneficial effect of ginger rhizome to protect against focal cerebral ischemia.

  12. Control of Cerebral Blood Velocity with Furosemide-Induced Hypovolemia and Upright Tilt

    Science.gov (United States)

    2010-11-25

    cardiovascular and cerebrovascular control mechanisms, subjects abstained from caffeine , exercise, and alcohol for 24 h before the experiment. Additionally...does not necessarily imply unchanging flow. For exam - ple, Heistad and Kontos (17) suggested implicitly that cerebral autoregulation reflects the

  13. Effects of interventions with therapeutic suits (clothing) on impairments and functional limitations of children with cerebral palsy: a systematic review.

    Science.gov (United States)

    Almeida, Kênnea M; Fonseca, Sérgio T; Figueiredo, Priscilla R P; Aquino, Amanda A; Mancini, Marisa C

    2017-07-05

    Therapeutic suits or clothing whether associated with intensive protocols or not, became popular in the rehabilitation of children with cerebral palsy. Studies have reported positive effects of these suits on children's posture, balance, motor function and gait. A summary of current literature may help guide therapeutic actions. To evaluate the available evidence on the effects of interventions based on the use of therapeutic suits in the treatment of impairments and functional limitations of children with cerebral palsy. Three independent reviewers searched for experimental studies on MEDLINE, SciELO, BIREME, LILACS, PEDro and CENTRAL databases, between October and December 2015 and updated in May 2016. The reviewers evaluated the methodological quality of selected studies using the Checklist for Measuring Quality. The Grading of Recommendations Assessment, Development and Evaluation was used to synthesize the quality of evidence and strength of recommendation. From the 13 studies, two evaluated the Full Body Suit, two tested the Dynamic Elastomeric Fabric Orthose, three evaluated TheraTogs and six tested the TheraSuit/AdeliSuit protocols. The quality of evidence for the Full Body Suit, the Dynamic Elastomeric Fabric Orthose and the TheraSuit/AdeliSuit protocols was very low for body structure and function outcomes, while the evidence for TheraTogs was low quality. Regarding the activity outcomes, the Full Body Suit and TheraSuit showed very low quality evidence while the evidence for TheraSuit/AdeliSuit protocols were of low quality. Enthusiasm with new therapeutic approaches that argue modifications in the neuromusculoskeletal impairments and functional limitations of children with cerebral palsy need to be guided by scientific evaluation. The low quality of evidence suggests caution in recommending the use of these therapeutic suits. New studies could change the findings of this review. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em

  14. The Influence of Motor Impairment on Autonomic Heart Rate Modulation among Children with Cerebral Palsy

    Science.gov (United States)

    Zamuner, Antonio Roberto; Cunha, Andrea Baraldi; da Silva, Ester; Negri, Ana Paola; Tudella, Eloisa; Moreno, Marlene Aparecida

    2011-01-01

    The study of heart rate variability is an important tool for a noninvasive evaluation of the neurocardiac integrity. The present study aims to evaluate the autonomic heart rate modulation in supine and standing positions in 12 children diagnosed with cerebral palsy and 16 children with typical motor development (control group), as well as to…

  15. Impaired Mitochondrial Respiration in Large Cerebral Arteries of Rats with Type 2 Diabetes.

    Science.gov (United States)

    Merdzo, Ivan; Rutkai, Ibolya; Sure, Venkata N L R; McNulty, Catherine A; Katakam, Prasad V G; Busija, David W

    2017-01-01

    Mitochondrial dysfunction has been suggested as a potential underlying cause of pathological conditions associated with type 2 diabetes (T2DM). We have previously shown that mitochondrial respiration and mitochondrial protein levels were similar in the large cerebral arteries of insulin-resistant Zucker obese rats and their lean controls. In this study, we extend our investigations into the mitochondrial dynamics of the cerebral vasculature of 14-week-old Zucker diabetic fatty obese (ZDFO) rats with early T2DM. Body weight and blood glucose levels were significantly higher in the ZDFO group, and basal mitochondrial respiration and proton leak were significantly decreased in the large cerebral arteries of the ZDFO rats compared with the lean controls (ZDFL). The expression of the mitochondrial proteins total manganese superoxide dismutase (MnSOD) and voltage-dependent anion channel (VDAC) were significantly lower in the cerebral microvessels, and acetylated MnSOD levels were significantly reduced in the large arteries of the ZDFO group. Additionally, superoxide production was significantly increased in the microvessels of the ZDFO group. Despite evidence of increased oxidative stress in ZDFO, exogenous SOD was not able to restore mitochondrial respiration in the ZDFO rats. Our results show, for the first time, that mitochondrial respiration and protein levels are compromised during the early stages of T2DM. © 2017 S. Karger AG, Basel.

  16. The Influence of Motor Impairment on Autonomic Heart Rate Modulation among Children with Cerebral Palsy

    Science.gov (United States)

    Zamuner, Antonio Roberto; Cunha, Andrea Baraldi; da Silva, Ester; Negri, Ana Paola; Tudella, Eloisa; Moreno, Marlene Aparecida

    2011-01-01

    The study of heart rate variability is an important tool for a noninvasive evaluation of the neurocardiac integrity. The present study aims to evaluate the autonomic heart rate modulation in supine and standing positions in 12 children diagnosed with cerebral palsy and 16 children with typical motor development (control group), as well as to…

  17. Salidroside prevents cognitive impairment induced by chronic cerebral hypoperfusion in rats.

    Science.gov (United States)

    Yan, Zhi-Qiang; Chen, Jun; Xing, Guo-Xiang; Huang, Jian-Guo; Hou, Xiang-Hong; Zhang, Yong

    2015-06-01

    To investigate the effects of salidroside on cognitive dysfunction induced by chronic cerebral hypoperfusion in rats. Male Sprague-Dawley rats (n = 36) were divided into three groups (n = 12 per group): sham operation; bilateral permanent occlusion of the common carotid arteries (2-VO); 2-VO + salidroside. Rats received 20 mg/kg per day salidroside or vehicle intraperitoneal injection beginning the day before surgery and continuing until 34 days postoperatively. Cognitive function was evaluated by Morris water maze test and hippocampal long-term potentiation (LTP) measurement. Hippocampal neuronal apoptosis was evaluated via immunofluorescence. Chronic cerebral hypoperfusion caused marked cognitive deficit and LTP inhibition. These effects were largely ameliorated by salidroside administration. Salidroside prevented caspase-3 activation, increased the ratio of Bax/Bcl-2, and reversed hippocampal neuronal loss induced by chronic cerebral hypoperfusion. Salidroside prevents cognitive deficits caused by chronic cerebral hypoperfusion in rats, and alleviates apoptosis in the hippocampal CA1 area. © The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  18. Ocular Blood Flow Autoregulation Mechanisms and Methods

    Directory of Open Access Journals (Sweden)

    Xue Luo

    2015-01-01

    Full Text Available The main function of ocular blood flow is to supply sufficient oxygen and nutrients to the eye. Local blood vessels resistance regulates overall blood distribution to the eye and can vary rapidly over time depending on ocular need. Under normal conditions, the relation between blood flow and perfusion pressure in the eye is autoregulated. Basically, autoregulation is a capacity to maintain a relatively constant level of blood flow in the presence of changes in ocular perfusion pressure and varied metabolic demand. In addition, ocular blood flow dysregulation has been demonstrated as an independent risk factor to many ocular diseases. For instance, ocular perfusion pressure plays key role in the progression of retinopathy such as glaucoma and diabetic retinopathy. In this review, different direct and indirect techniques to measure ocular blood flow and the effect of myogenic and neurogenic mechanisms on ocular blood flow are discussed. Moreover, ocular blood flow regulation in ocular disease will be described.

  19. [Autoregulation of stress response in microorganisms].

    Science.gov (United States)

    Nikolaev, Iu A; Muliukin, A L; Stepanenko, I Iu; El'-Registan, G I

    2006-01-01

    Examples are considered of the involvement of low-molecular-weight autoregulators in the development of resistance of proliferating microbial cultures to unfavorable environmental impacts of various intensity, including impacts programmed to occur in the developmental cycle ("new medium stress," starvation stress) and nonprogrammed impacts. It was shown that extracellular adaptation factors control the reversible adhesion of cells in submerged cultures and the processes of cell reactivation in the poststress period and are involved in the stabilization of cellular biopolymers (proteins and DNA) and subcellular structures (membranes); the adaptogens of the phenolic type also act as efficient scavengers of reactive oxygen species. The protective effect of the adaptogenic autoregulators is manifested in the increase of resistance of microbial cells to stressors of various nature and in the preservation of the cell proliferative capacity.

  20. Association of Chronic Kidney Disease and Cerebral Small Vessel Disease with Cognitive Impairment in Elderly Patients with Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Toshitaka Umemura

    2013-07-01

    Full Text Available Background/Aims: In recent years, the relationship between chronic kidney disease (CKD and cognitive impairment has been attracting attention. Cerebral small vessel disease (SVD is also associated with an increased risk of cognitive impairment. However, it is still unknown whether CKD markers are associated with cognitive impairment independently of SVD in elderly diabetic patients. Methods: Seventy-nine type 2 diabetic patients (mean age, 76.0 years were enrolled in the present study. CKD was defined as the presence of albuminuria and/or a low estimated glomerular filtration rate (eGFR 2. SVD was evaluated by the presence and severity of silent brain infarcts (SBIs and white matter lesions (WMLs on brain magnetic resonance imaging. Neuropsychological tests were assessed using four validated cognitive instruments. Results: In multiple linear regression analyses, albuminuria was associated with worse modified Stroop Color Word scores (β = 0.284, p = 0.017 and low eGFR was associated with reduced Digit Symbol Substitution scores (β = -0.224, p = 0.026 after adjustment for age, sex, education years, diabetes duration, hypertension, multiple SBIs, and advanced WMLs. In contrast, there were no significant associations between CKD markers and Mini-Mental State Examination or Word Recall scores. Conclusion: Our findings suggest that albuminuria and low eGFR are associated with frontal lobe dysfunction independently of SVD in elderly type 2 diabetic patients.

  1. Assessment of cerebral visual impairment with the L94 visual perceptual battery: clinical value and correlation with MRI findings.

    Science.gov (United States)

    Ortibus, E; Lagae, L; Casteels, I; Demaerel, P; Stiers, P

    2009-03-01

    In this article we describe visual perceptual abilities of a clinical population, referred for visual problems to our multidisciplinary team and assessed with the five computer tasks from the L94 visual perceptual battery. Clinical and neuroimaging findings were correlated with the findings on this task battery. Seventy children (35 males, 35 females) constituted our cohort. Age ranged from 4 to 20 years (mean 7y [SD 3y]). Forty children were born before 37 weeks gestational age. Thirty-six children had cerebral palsy (CP), of whom 24 had spastic diplegia, five had spastic hemiplegia, and four had spastic quadriplegia. Three children had ataxic CP. Perceptual visual impairment (PVI) was established in comparison to the performance age obtained on non-verbal intelligence subtests, instead of chronological age. Our results suggest that children with a history of preterm birth and a clinical CP picture are most at risk for a specific PVI. Correlations among other clinical variables did not define a clinical subgroup more at risk. Children with periventricular leucomalacia were almost equally represented in both PVI and non-PVI groups. Normal magnetic resonance imaging did not exclude the presence of PVI. In these children, however, we found another impairment profile, more in favour of dorsal stream impairment.

  2. Cerebral microbleeds in patients with mild cognitive impairment and small vessel disease: The Vascular Mild Cognitive Impairment (VMCI)-Tuscany study.

    Science.gov (United States)

    Valenti, Raffaella; Del Bene, Alessandra; Poggesi, Anna; Ginestroni, Andrea; Salvadori, Emilia; Pracucci, Giovanni; Ciolli, Laura; Marini, Sandro; Nannucci, Serena; Pasi, Marco; Pescini, Francesca; Diciotti, Stefano; Orlandi, Giovanni; Cosottini, Mirco; Chiti, Alberto; Mascalchi, Mario; Bonuccelli, Ubaldo; Inzitari, Domenico; Pantoni, Leonardo

    2016-09-15

    Cerebral microbleeds (CMBs) are a neuroimaging expression of small vessel disease (SVD). We investigated in a cohort of SVD patients with mild cognitive impairment (MCI): 1) the reliability of the Microbleed Anatomical Rating Scale (MARS); 2) the burden and location of CMBs and their association with cognitive performances, independent of other clinical and neuroimaging features. Patients underwent clinical, neuropsychological (4 cognitive domains), and MRI assessments. CMBs were assessed by three raters. Out of the 152 patients (57.2% males; mean age±SD: 75.5±6.7years) with gradient-echo (GRE) sequences, 41 (27%) had at least one CMB. Inter-rater agreement for number and location of CMBs ranged from good to very good [multi-rater Fleiss kappa (95%CI): 0.70-0.95]. Lacunar infarcts and some clinical variables (e.g., hypertension and physical activity) were associated with CMBs in specific regions. Total number of CMBs and of those in deep and lobar regions were associated with attention/executive and fluency domains. MARS is a reliable instrument to assess CMBs in SVD patients with MCI. Nearly one third of these patients had at least one CMB. Total CMBs burden was associated with attention/executive functions and fluency domains impairment, lacunar infarcts, and with some potentially modifiable risk factors. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Model-based Quantification of Cerebral Hemodynamics as a Physiomarker for Alzheimer’s Disease?

    Science.gov (United States)

    Marmarelis, V. Z.; Shin, D. C.; Orme, M. E.; Zhang, R.

    2013-01-01

    Previous studies have found that Alzheimer’s disease (AD) impairs cerebral vascular function, even at early stages of the disease. This offers the prospect of a useful diagnostic method for AD, if cerebral vascular dysfunction can be quantified reliably within practical clinical constraints. We present a recently developed methodology that utilizes a data-based dynamic nonlinear closed-loop model of cerebral hemodynamics to compute “physiomarkers” quantifying the state of cerebral flow autoregulation to pressure-changes (CA) and cerebral CO2 vasomotor reactivity (CVMR) in each subject. This model is estimated from beat-to-beat measurements of mean arterial blood pressure, mean cerebral blood flow velocity and end-tidal CO2, which can be made reliably and non-invasively under resting conditions. This model may also take an open-loop form and comparisons are made with the closed-loop counterpart. The proposed model-based physiomarkers take the form of two indices that quantify the gain of the CA and CVMR processes in each subject. It was found in an initial set of clinical data that the CVMR index delineates AD patients from control subjects and, therefore, may prove useful in the improved diagnosis of early-stage AD. PMID:23771298

  4. [Alterations in cerebral perfusion in patients with systemic sclerosis and cognitive impairment].

    Science.gov (United States)

    Moreno-Gutiérrez, Juan; Coria-Moctezuma, Luis Alonso; del Pilar Cruz-Domínguez, María; Vera-Lastra, Olga Lidia

    2015-01-01

    Introducción: la esclerosis sistémica (ES) es una enfermedad autoinmune, sistémica, caracterizada por fibrosis, alteraciones inmunológicas y vasculares. La hipoperfusión cerebral puede ser causada por isquemia. Los trastornos cognitivos son causa importante de morbilidad. El objetivo de este estudio fue determinar la frecuencia de alteraciones en la perfusión cerebral (PC) en pacientes con ES y deterioro cognitivo (DC). Métodos: se estudiaron 88 pacientes con ES. A todos se les aplicó el Test de Montreal (TM) para evaluar el DC. A 15 pacientes con DC que cumplieron con los criterios (sin hipertensión arterial sistémica, diabetes mellitus, evento vascular cerebral, vasculitis, hipotiroidismo, depresión, sin ingesta de fármacos que interfieran con la evaluación cognitiva), se les midió la PC mediante Gamagrama Cerebral Perfusorio (GCP).Resultados: de los 88 pacientes con ES, 58 tuvieron DC con el TM. La PC se encontró disminuida en 12/15. La disminución de la PC se observó en los siguientes lóbulos (frontal en 9/15; temporal en 7/15, y parietal en 3/15. La concordancia entre el TM y GC fue 60 % para el lóbulo frontal, 46 % para el lóbulo temporal y 13 % parietal.Conclusiones: el DC es frecuente en la ES, la disminución de la PC fue más común en el lóbulo frontal, predominado en los pacientes de mayor edad y tiempo de evolución de la ES.

  5. Genetic enhancement of microsomal epoxide hydrolase improves metabolic detoxification but impairs cerebral blood flow regulation.

    Science.gov (United States)

    Marowsky, Anne; Haenel, Karen; Bockamp, Ernesto; Heck, Rosario; Rutishauser, Sibylle; Mule, Nandkishor; Kindler, Diana; Rudin, Markus; Arand, Michael

    2016-12-01

    Microsomal epoxide hydrolase (mEH) is a detoxifying enzyme for xenobiotic compounds. Enzymatic activity of mEH can be greatly increased by a point mutation, leading to an E404D amino acid exchange in its catalytic triad. Surprisingly, this variant is not found in any vertebrate species, despite the obvious advantage of accelerated detoxification. We hypothesized that this evolutionary avoidance is due to the fact that the mEH plays a dualistic role in detoxification and control of endogenous vascular signaling molecules. To test this, we generated mEH E404D mice and assessed them for detoxification capacity and vascular dynamics. In liver microsomes from these mice, turnover of the xenobiotic compound phenanthrene-9,10-oxide was four times faster compared to WT liver microsomes, confirming accelerated detoxification. mEH E404D animals also showed faster metabolization of a specific class of endogenous eicosanoids, arachidonic acid-derived epoxyeicosatrienoic acids (EETs) to dihydroxyeicosatrienoic acids (DHETs). Significantly higher DHETs/EETs ratios were found in mEH E404D liver, urine, plasma, brain and cerebral endothelial cells compared to WT controls, suggesting a broad impact of the mEH mutant on endogenous EETs metabolism. Because EETs are strong vasodilators in cerebral vasculature, hemodynamics were assessed in mEH E404D and WT cerebral cortex and hippocampus using cerebral blood volume (CBV)-based functional magnetic resonance imaging (fMRI). Basal CBV0 levels were similar between mEH E404D and control mice in both brain areas. But vascular reactivity and vasodilation in response to the vasodilatory drug acetazolamide were reduced in mEH E404D forebrain compared to WT controls by factor 3 and 2.6, respectively. These results demonstrate a critical role for mEH E404D in vasodynamics and suggest that deregulation of endogenous signaling pathways is the undesirable gain of function associated with the E404D variant.

  6. [Changes in the cerebral hemodynamics during Rohypnol anesthesia in neurosurgical patients].

    Science.gov (United States)

    Gribkov, A V; Bakunin, L M; Rufova, N Iu

    1994-01-01

    Intracranial pressure, cerebral perfusion pressure, and intracerebral blood volume changes were observed in 43 patients with volumetric intracranial processes (intracranial hematomas, tumors) during general rohypnol anesthesia. Intracranial and cerebral perfusion pressures were found to correlate with intracerebral blood volume. Rohypnol anesthesia decreased intracranial pressure by 25% due to reduced arterial blood influx into the head, mechanisms responsible for autoregulation of cerebral circulation being intact.

  7. Modulation of cerebral blood flow with transcutaneous electrical neurostimulation (TENS) in patients with cerebral vasospasm after subarachnoid hemorrhage

    NARCIS (Netherlands)

    ter Laan, Mark; van Dijk, J.M.C.; Stewart, Roy; Staal, Michiel J; Elting, Jan-Willem J

    2014-01-01

    ObjectivesTranscutaneous electrical neurostimulation (TENS) and spinal cord stimulation have been shown to increase peripheral and cerebral blood flow. We postulate that certain pathological conditions attenuate cerebral autoregulation, which may result in a relative increase of the importance of ne

  8. Effect of high dose fish oil supplementation on cerebral blood flow and cognitive performance in patients with mild cognitive impairment: a proof of concept study

    NARCIS (Netherlands)

    Rest, van de O.; Claassen, J.A.; Kessels, R.P.C.; Geleijnse, J.M.; Olde Rikkert, M.G.M.; Groot, de C.P.G.M.

    2013-01-01

    Objective: The current study aimed to examine the effect of n-3 polyunsaturated fatty acids (PUFAs) on cerebral blood flow and age-related loss of cognitive functioning in subjects diagnosed with mild cognitive impairment (MCI). Design, setting and participants: A total of 20 patients with single or

  9. Cerebral blood flow in the neonate.

    Science.gov (United States)

    Vutskits, Laszlo

    2014-01-01

    Ensuring adequate oxygenation of the developing brain is the cornerstone of neonatal critical care. Despite decades of clinical research dedicated to this issue of paramount importance, our knowledge and understanding regarding the physiology and pathophysiology of neonatal cerebral blood flow are still rudimentary. This review primarily focuses on currently available human clinical and experimental data on cerebral blood flow and autoregulation in the preterm and term infant. Limitations of systemic blood pressure values as surrogates for monitoring adequate cerebral oxygen delivery are discussed. Particular emphasis is placed on the high interindividual variability in cerebral blood flow values, vasoreactivity, and autoregulatory thresholds making the applications of normative values highly questionable. Technical and ethical difficulties to conduct such trials leave us with a near complete lack of knowledge on how pharmacological and surgical interventions impact on cerebral autoregulation. The ensemble of these works argues for the necessity of highly individualized care by taking advantage of continuous bedside monitoring of cerebral circulation. They also point to the urgent need for further studies addressing the exciting but difficult issue of cerebral blood flow autoregulation in the neonate.

  10. Pulsatile Intracranial Pressure and Cerebral Autoregulation After Traumatic Brain Injury

    NARCIS (Netherlands)

    Radolovich, D. K.; Aries, M.J.H.; Castellani, G.; Corona, A.; Lavinio, A.; Smielewski, P.; Pickard, J. D.; Czosnyka, M.

    2011-01-01

    Strong correlation between mean intracranial pressure (ICP) and its pulse wave amplitude (AMP) has been demonstrated in different clinical scenarios. We investigated the relationship between invasive mean arterial blood pressure (ABP) and AMP to explore its potential role as a descriptor of cerebrov

  11. Determination of interventions for upper extremity tactile impairment in children with cerebral palsy: a systematic review.

    Science.gov (United States)

    Auld, Megan L; Russo, Remo; Moseley, G Lorimer; Johnston, Leanne M

    2014-09-01

    This study reviewed interventions suitable for treating tactile dysfunction in children with cerebral palsy (CP). A systematic review was conducted of six databases, searched for population: ('brain injury' OR 'cerebral palsy' OR 'stroke' OR 'cerebrovascular accident') and intervention: ('tactile' OR 'sensation'). Inclusion criteria were: (1) published after 1950 in English; (2) participants older than 4 years with brain injury; (3) upper limb intervention; and (4) examined tactile registration or perception. Of 2938 studies identified, 30 met the inclusion criteria. Results from included studies indicated that tactile function improved in adults with stroke after transfer enhanced training (t[47]=2.75, p=0.004), stimulus specific training (ptherapy (F=5.71, p=0.028), mirror therapy (F=7.7, p=0.009), and functional deafferentation using an anaesthetic cream (t=3.76; pchildren with CP. Research is required to develop tactile interventions for children with CP that integrate methodology from effective approaches for adults after stroke. Stimulus specific training, transfer enhanced training, and mirror therapy are promising. Other approaches are less suitable for children because of invasiveness (electrical stimulation), safety (ice therapy), or limitation of bimanual function (eutectic mixture of local anaesthetics, pneumatic cuff). © 2014 Mac Keith Press.

  12. Consonant production and overall speech characteristics in school-aged children with cerebral palsy and speech impairment.

    Science.gov (United States)

    Nordberg, Ann; Miniscalco, Carmela; Lohmander, Anette

    2014-08-01

    The aim of the present study was to investigate the speech characteristics of school-aged children with cerebral palsy (CP) and speech impairment at various cognitive levels. Nineteen children with a mean age of 11;2 years (9;2-12;9 years) with spastic, dyskinetic, and ataxic CP and speech impairment participated. Phonetic transcription of oral consonants, ratings of hypernasality, and severity of overall dysarthria, together with free field descriptions of respiration, voice quality, and prosody, were performed independently by two speech-language pathologists. The non-verbal cognitive level was also studied. More than half of the children had large problems with the articulation of consonants, and the children with ataxic CP were most affected. The majority was rated as having dysarthria, mostly mild, but hypernasality was rare. Gross motor problems were not significantly associated with the articulation of consonants or the severity of dysarthria, whereas non-verbal cognitive level was. This underlines the importance of taking non-verbal cognitive level into account, when designing individual speech treatment programs for this group of children. Finally, a careful examination of the articulation of consonants is recommended in order to study speech production thoroughly in children with CP.

  13. The Danish Cerebral Palsy Registry. A registry on a specific impairment

    DEFF Research Database (Denmark)

    Uldall, P; Michelsen, Susan Ishøy; Topp, M;

    2001-01-01

    are collected from paediatric departments and one special institution for disabled children. The children are included by a child neurologist and an obstetrician, and information on pregnancy, birth, neonatal period, impairments and demographic data on the child and mother are registered in a standard form...

  14. Intranasal insulin improves cerebral blood flow, Nrf-2 expression and BDNF in STZ (ICV)-induced memory impaired rats.

    Science.gov (United States)

    Rajasekar, N; Nath, Chandishwar; Hanif, Kashif; Shukla, Rakesh

    2017-03-15

    Insulin/insulin receptor signaling is involved in cognitive functions. Clinical studies have shown that intranasal insulin administration improves memory functions. However, the molecular mechanisms associated with improvement in memory functions are largely unexplored. Therefore, we investigated the protective effect of intranasal insulin in intracerebroventricular (ICV) streptozotocin (STZ) induced memory impairment in rats. Rats were injected with STZ (3mg/kg, ICV) bilaterally twice, on days 1 and 3 and intranasal insulin (2IU/rat/day) was given for 14days. Memory was assessed by Morris water maze test. Cerebral blood flow (CBF) was measured by laser-Doppler flowmetry. The biochemical and molecular studies were done in cortex and hippocampus of rat brain. STZ (ICV) administration caused memory impairment along with the reduction of CBF, ATP level, and Nrf-2 expression. Treatment with intranasal insulin significantly improved memory functions as well as restored CBF, ATP content and Nrf-2 expression in STZ injected rats. STZ administration stimulated oxidative-nitrosative stress as evidenced by a significant increase in ROS, malondialdehyde, NO level and inducible nitric oxide synthase expression and the decrease in glutathione level; which was normalized by intranasal insulin delivery. STZ-induced cholinergic dysfunction (AChE activity and α7-nAChR expression), and mitochondrial hypofunction was largely prevented by treatment with intranasal insulin. Intranasal insulin delivery successfully restored BDNF level and pCREB expression in STZ injected rats. The study shows the beneficial effects of intranasal insulin against STZ-induced memory impairment, which attributed to improved CBF, cholinergic function, brain energy metabolism, BDNF, Nrf-2 expression and antioxidative action. Copyright © 2016. Published by Elsevier Inc.

  15. Porcine Brain Extract Attenuates Memory Impairments Induced by Focal Cerebral Ischemia

    Directory of Open Access Journals (Sweden)

    Jinatta Jittiwat

    2009-01-01

    Full Text Available Problem statement: Stroke or cerebral ischemia has been recognized as one important problem worldwide. To date, the effectiveness of protective and therapeutic strategies against stroke is still very limited. Therefore, the development of novel strategy is required. Porcine brain is traditional believed to improve brain functions. Recent studies showed that the extract of porcine brain could protect against brain damage related to the oxidative stress, therefore, we hypothesized that it could protect against brain damage in stroke. Approach: To test the potential of porcine brain extract as the novel protective supplement against stroke, various doses of porcine brain extract at doses of 0.5 and 2.5 mg kg-1 b.w. were orally given to male Wistar rats, weighing 300-350 g, at the period of 14 days before and 21 days after the occlusion of right middle cerebral artery. Then, all rats were determined the neurological score, motor performance, cognitive function and brain infarct volume. Moreover, the possible neuroprotective mechanisms of the extract were also determined via the alteration of Malondialdehyde (MDA or lipid peroxidation product and via the activities of scavenger enzymes including Superoxide Dismutase (SOD, Catalase (CAT and Glutathione Peroxides (GPx. Results: The results showed that the low dose of porcine extract decreased the infarct volume and improved brain functions including neurological score, motor performance and memory deficit. In addition, it also decreased MDA but increased the activities of SOD, CAT and GPx. Conclusion: Our results suggested the potential role of porcine brain extract as neuroprotectant. The possible underlying mechanism appeared to be related to the enhanced activities of SOD, CAT and GPx which in turn resulted in the decrease MDA. Moreover, our findings may shed light on the pharmacologic basis for the clinical application of traditional Chinese medicine to protect against stroke.

  16. Dosimetry of patients submitted to cerebral PET/CT for the diagnosis of mild cognitive impairment

    Energy Technology Data Exchange (ETDEWEB)

    Santana, Priscila do Carmo; Oliveira, Paulo Marcio Campos de; Bernardes, Felipe Dias; Mamede, Marcelo, E-mail: pridili@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Mourao, Arnaldo Prata [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET), Belo Horizonte, MG (Brazil); Silva, Teogenes Augusto da [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2014-11-15

    Objective: the present study was aimed at evaluating the effective radiation dose in patients submitted to PET/CT for the diagnosis of mild cognitive impairment. Materials and methods: TLD-100 detectors inserted into an Alderson Rando® anthropomorphic phantom were utilized to measure the absorbed dose coming from the CT imaging modality. The anthropomorphic phantoms (male and female adult versions) were submitted to the same technical protocols for patients’ images acquisition. The absorbed dose resulting from the radiopharmaceutical injection was estimated by means of the model proposed by the ICRP publication 106. Results: the effective dose in patients submitted to this diagnostic technique was approximately (5.34 ± 1.99) mSv. Conclusion: optimized protocols for calculation of radioactive activity injected into patients submitted to this diagnostic technique might contribute to reduce the effective radiation dose resulting from PET/CT in the diagnosis of mild cognitive impairment. (author)

  17. Dosimetry of patients submitted to cerebral PET/CT for the diagnosis of mild cognitive impairment.

    Science.gov (United States)

    Santana, Priscila do Carmo; Mourão, Arnaldo Prata; de Oliveira, Paulo Márcio Campos; Bernardes, Felipe Dias; Mamede, Marcelo; da Silva, Teógenes Augusto

    2014-01-01

    The present study was aimed at evaluating the effective radiation dose in patients submitted to PET/CT for the diagnosis of mild cognitive impairment. TLD-100 detectors inserted into an Alderson Rando® anthropomorphic phantom were utilized to measure the absorbed dose coming from the CT imaging modality. The anthropomorphic phantoms (male and female adult versions) were submitted to the same technical protocols for patients' images acquisition. The absorbed dose resulting from the radiopharmaceutical injection was estimated by means of the model proposed by the ICRP publication 106. The effective dose in patients submitted to this diagnostic technique was approximately (5.34 ± 1.99) mSv. Optimized protocols for calculation of radioactive activity injected into patients submitted to this diagnostic technique might contribute to reduce the effective radiation dose resulting from PET/CT in the diagnosis of mild cognitive impairment.

  18. SPECT imaging of GABA{sub A}/benzodiazepine receptors and cerebral perfusion in mild cognitive impairment

    Energy Technology Data Exchange (ETDEWEB)

    Pappata, Sabina; Varrone, Andrea; Vicidomini, Caterina; Sansone, Valeria; Comerci, Marco; Panico, Maria Rosaria; Quarantelli, Mario [CNR, Institute of Biostructure and Bioimaging, Naples (Italy); Milan, Graziella; De Falco, Caterina; Lore, Elisa; Postiglione, Alfredo [University ' ' Federico II' ' , Department of Clinical and Experimental Medicine, Naples (Italy); Iavarone, Alessandro [Neurologic and Stroke Unit, CTO Hospital, Naples (Italy); Salvatore, Marco [CNR, Institute of Biostructure and Bioimaging, Naples (Italy); University ' ' Federico II' ' , Department of Biomorphological and Functional Sciences, Naples (Italy)

    2010-06-15

    The involvement of neocortical and limbic GABA{sub A}/benzodiazepine (BZD) receptors in Alzheimer's disease (AD) is controversial and mainly reported in advanced stages. The status of these receptors in the very early stages of AD is unclear and has not been explored in vivo. Our aims were to investigate in vivo the integrity of cerebral cortical GABA{sub A}/BZD receptors in subjects with amnestic mild cognitive impairment (MCI) and to compare possible receptor changes to those in cerebral perfusion. [{sup 123}I]Iomazenil and [{sup 99m}Tc]HMPAO SPECT images were acquired in 16 patients with amnestic MCI and in 14 normal elderly control subjects (only [{sup 123}I]iomazenil imaging in 5, only [{sup 99m}Tc]HMPAO imaging in 4, and both [{sup 123}I]iomazenil and [{sup 99m}Tc]HMPAO imaging in 5). Region of interest (ROI) analysis and voxel-based analysis were performed with cerebellar normalization. Neither ROI analysis nor voxel-based analysis showed significant [{sup 123}I]iomazenil binding changes in MCI patients compared to control subjects, either as a whole group or when considering only those patients with MCI that converted to AD within 2 years of clinical follow-up. In contrast, the ROI analysis revealed significant hypoperfusion of the precuneus and posterior cingulate cortex in the whole group of MCI patients and in MCI converters as compared to control subjects. Voxel-based analysis showed similar results. These results indicate that in the very early stages of AD, neocortical and limbic neurons/synapses expressing GABA{sub A}/BZD receptors are essentially preserved. They suggest that in MCI patients functional changes precede neuronal/synaptic loss in neocortical posterior regions and that [{sup 99m}Tc]HMPAO rCBF imaging is more sensitive than [{sup 123}I]iomazenil GABA{sub A}/BZD receptor imaging in detecting prodromal AD. (orig.)

  19. NOC/oFQ contributes to hypoxic-ischemic impairment of N-methyl-D-aspartate-induced cerebral vasodilation.

    Science.gov (United States)

    Armstead, W M

    2000-06-16

    Previous studies in piglets show that either hypoxia, ischemia-reperfusion (I+R) or combined hypoxia-ischemia-reperfusion (H+I+R) attenuated N-methyl-D-aspartate (NMDA)-induced pial artery dilation. This study was designed to determine the contribution of the newly described opioid nociceptin orphanin FQ (NOC/oFQ) to hypoxic-ischemic impairment of NMDA induced cerebral vasodilation in piglets equipped with a closed cranial window. Global cerebral ischemia was produced via elevated intracranial pressure. Hypoxia decreased P(O(2)) to 35+/-3 mmHg with unchanged P(CO(2)). I+R elevated CSF NOC/oFQ from 67+/-4 to 266+/-29 pg/ml ( approximately 10(-10) M) while H+I+R elevated CSF NOC/oFQ to 483+/-67 pg/ml within 1 h of reperfusion. Such elevated NOC/oFQ levels returned to control within 4 h in I+R animals and within 12 h in H+I+R animals. Topical NOC/oFQ (10(-10) M) had no effect on pial artery diameter by itself but attenuated NMDA (10(-8), 10(-6) M) induced pial dilation (control, 9+/-1 and 16+/-1; coadministered NOC/oFQ, 5+/-1 and 10+/-1%). NMDA induced pial artery dilation was attenuated by I+R or H+I+R; but such dilation was partially restored by pretreatment with the putative NOC/oFQ antagonist [F/G] NOC/oFQ (1-13) NH(2) (10(-6) M) (control, 9+/-1 and 16+/-1; I+R, 3+/-1 and 5+/-1; I+R+NOC/oFQ antagonist, 6+/-1 and 11+/-1%) Similar results were obtained for glutamate. These data suggest that NOC/oFQ release contributes to impaired NMDA and glutamate-induced cerebrovasodilation following I+R or H+I+R.

  20. Aberrant cerebral network topology and mild cognitive impairment in early Parkinson's disease.

    Science.gov (United States)

    Pereira, Joana B; Aarsland, Dag; Ginestet, Cedric E; Lebedev, Alexander V; Wahlund, Lars-Olof; Simmons, Andrew; Volpe, Giovanni; Westman, Eric

    2015-08-01

    The aim of this study was to assess whether mild cognitive impairment (MCI) is associated with disruption in large-scale structural networks in newly diagnosed, drug-naïve patients with Parkinson's disease (PD). Graph theoretical analyses were applied to 3T MRI data from 123 PD patients and 56 controls from the Parkinson's progression markers initiative (PPMI). Thirty-three patients were classified as having Parkinson's disease with mild cognitive impairment (PD-MCI) using the Movement Disorders Society Task Force criteria, while the remaining 90 PD patients were classified as cognitively normal (PD-CN). Global measures (clustering coefficient, characteristic path length, global efficiency, small-worldness) and regional measures (regional clustering coefficient, regional efficiency, hubs) were assessed in the structural networks that were constructed based on cortical thickness and subcortical volume data. PD-MCI patients showed a marked reduction in the average correlation strength between cortical and subcortical regions compared with controls. These patients had a larger characteristic path length and reduced global efficiency in addition to a lower regional efficiency in frontal and parietal regions compared with PD-CN patients and controls. A reorganization of the highly connected regions in the network was observed in both groups of patients. This study shows that the earliest stages of cognitive decline in PD are associated with a disruption in the large-scale coordination of the brain network and with a decrease of the efficiency of parallel information processing. These changes are likely to signal further cognitive decline and provide support to the role of aberrant network topology in cognitive impairment in patients with early PD.

  1. Theory of mind and the right cerebral hemisphere: refining the scope of impairment.

    Science.gov (United States)

    Griffin, Richard; Friedman, Ori; Ween, Jon; Winner, Ellen; Happé, Francesca; Brownell, Hiram

    2006-05-01

    The neuropsychological and functional characterisation of mental state attribution ("theory of mind" (ToM)) has been the focus of several recent studies. The literature contains opposing views on the functional specificity of ToM and on the neuroanatomical structures most relevant to ToM. Studies with brain-lesioned patients have consistently found ToM deficits associated with unilateral right hemisphere damage (RHD). Also, functional imaging performed with non-brain-injured adults implicates several specific neural regions, many of which are located in the right hemisphere. The present study examined the separation of ToM impairment from other deficits associated with brain injury. We tested 11 patients with unilateral right hemisphere damage (RHD) and 20 normal controls (NC) on a humour rating task, an emotion rating task, a graded (first-order, second-order) ToM task with non-mentalistic control questions, and two ancillary measures: (1) Trails A and B, in order to assess overall level of impairment and set-shifting abilities associated with executive function, and (2) a homograph reading task to assess central coherence skills. Our findings indicate that RHD can result in a functionally specific deficit in attributing intentional states, particularly those involving second-order attributions. Performance on ToM questions was not reliably related to measures of cognitive impairment; however, performance on non-ToM control questions was reliably predicted by Trails A and B. We also discuss individual RHD patients' performance with attention to lesion locus. Our findings suggest that damage to the areas noted as specialised in neuroimaging studies may not affect ToM performance, and underscore the necessity of combining lesion and imaging studies in determining functional-anatomical relations.

  2. Impairment of tight junctions and glucose transport in endothelial cells of human cerebral cavernous malformations.

    Science.gov (United States)

    Schneider, Hannah; Errede, Mariella; Ulrich, Nils H; Virgintino, Daniela; Frei, Karl; Bertalanffy, Helmut

    2011-06-01

    Cerebral cavernous malformations (CCMs) often cause hemorrhages that can result in severe clinical manifestations, including hemiparesis and seizures. The underlying mechanisms of the aggressive behavior of CCMs are undetermined to date, but alterations of vascular matrix components may be involved. We compared the localization of the tight junction proteins (TJPs) in 12 CCM specimens and the expression of glucose transporter 1 (GLUT-1), which is sensitive to alterations in TJP levels, in 5 CCM specimens with those in 5 control temporal lobectomy specimens without CCM by immunofluorescence microscopy. The TJPs occludin, claudin-5, and zonula occludens ZO-1 were downregulated at intercellular contact sites and partly redistributed within the surrounding tissue in the CCM samples; there was also a marked reduction of GLUT-1 immunoreactivity compared with that in control specimens. Corresponding analysis using quantitative real-time reverse transcription polymerase chain reaction on 8 CCM and 8 control specimens revealed significant downregulation of mRNA expression of occludin, claudin-5, ZO-1, and GLUT-1. The altered expression and localization of the TJPs at interendothelial contact sites accompanied by a reduction of GLUT-1 expression in dilated CCM microvessels likely affect vascular matrix stability and may contribute to hemorrhages of CCMs.

  3. Tyrosine impairs enzymes of energy metabolism in cerebral cortex of rats.

    Science.gov (United States)

    de Andrade, Rodrigo Binkowski; Gemelli, Tanise; Rojas, Denise Bertin; Funchal, Cláudia; Dutra-Filho, Carlos Severo; Wannmacher, Clovis Milton Duval

    2012-05-01

    Tyrosine levels are abnormally elevated in tissues and physiological fluids of patients with inborn errors of tyrosine catabolism, especially in tyrosinemia type II, which is caused by deficiency of tyrosine aminotransferase and provokes eyes, skin, and central nervous system disturbances. Considering that the mechanisms of brain damage in these disorders are poorly known, in this study, we investigated the in vivo and in vitro effects of tyrosine on some parameters of energy metabolism in cerebral cortex of 14-day-old Wistar rats. We observed that 2 mM tyrosine inhibited in vitro the pyruvate kinase (PK) activity and that this inhibition was prevented by 1 mM reduced glutathione with 30, 60, and 90 min of preincubation. Moreover, administration of tyrosine methyl ester (TME) (0.5 mg/g of body weight) decreased the activity of PK and this reduction was prevented by pre-treatment with creatine (Cr). On the other hand, tyrosine did not alter adenylate kinase (AK) activity in vitro, but administration of TME enhanced AK activity not prevented by Cr pre-treatment. Finally, TME administration decreased the activity of CK from cytosolic and mitochondrial fractions and this diminution was prevented by Cr pre-treatment. The results suggest that tyrosine alters essential sulfhydryl groups necessary for CK and PK functions, possibly through oxidative stress. In case this also occurs in the patients, it is possible that energy metabolism alterations may contribute, along with other mechanisms, to the neurological dysfunction of hypertyrosinemias.

  4. Assistive technology for promoting choice behaviors in three children with cerebral palsy and severe communication impairments.

    Science.gov (United States)

    Stasolla, Fabrizio; Caffò, Alessandro O; Picucci, Luciana; Bosco, Andrea

    2013-09-01

    A technology-based program to promote independent choice behaviors by three children with cerebral palsy and multiple disabilities was assessed. The program was based on learning principles and assistive technology (i.e., customized input devices/sensors, personal computers, screening of preferred stimuli according to a binomial criterion). The first purpose of the present study was to provide the participants with a new set-up of assistive technology and to allow them to choose among three categories (i.e., food, beverage and leisure), and to request a specific item out of four in each category, adopting a procedure that minimized (according to a conditional probability criterion) unintentional choices. The second aim of the study was to carry out the effects of the program on detectable mood signs (i.e., happiness index). The study was conducted according to an ABAB sequence with a subsequent post intervention check for each participant. The results showed an increase of engagement and of the happiness index during intervention phases. Psychological as well as educational implications were discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Structural and functional cerebral impairments in cirrhotic patients with a history of overt hepatic encephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hua-Jun [Jiangsu Key Laboratory of Molecular Imaging and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing 210009 (China); Zhu, Xi-Qi [Jiangsu Key Laboratory of Molecular Imaging and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing 210009 (China); Department of Radiology, The Second Hospital of Nanjing, Medical School of Southeast University, Nanjing 210002 (China); Shu, Hao [Department of Neurology, Zhongda Hospital, Medical School of Southeast University, Nanjing 210009 (China); Yang, Ming; Zhang, Yi; Ding, Jie; Wang, Yu [Jiangsu Key Laboratory of Molecular Imaging and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing 210009 (China); Teng, Gao-Jun, E-mail: gjteng@vip.sina.com [Jiangsu Key Laboratory of Molecular Imaging and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing 210009 (China)

    2012-10-15

    Objective: Diffuse brain atrophy has been observed in cirrhotic patients and recent reports have revealed the persistence of cognitive impairment after clinical resolution of overt hepatic encephalopathy. We sought to explore the continued influence of overt hepatic encephalopathy on neurological function by measuring brain resting-state inherent connectivity, based on an investigation of structural abnormalities. Methods: Neuropsychological tests and structural and functional magnetic resonance scanning were conducted in 20 healthy controls and 21 cirrhotic patients with a history of overt hepatic encephalopathy. The analysis of voxel-based morphometry and functional connectivity were performed to detect the alterations in brain structure and function, respectively. Results: Patients showed significantly worse performance in neuropsychological tests as compared with controls, despite apparently normal mental status. Analysis of voxel-based morphometry revealed a decrease in gray matter volume primarily in the midline regions, bilateral insular cortex and caudates, left parahippocampal gyrus, and right cerebellum posterior lobe, while the volume of the bilateral thalamus showed an increase. Of these regions, the posterior cingulate cortex with peak atrophy was selected as the origin for the analysis of functional connectivity. Typical patterns of a default mode network were identified in both groups. Decreased functional connectivity was found in the medial prefrontal gyrus, left inferior parietal lobule, and left middle temporal gyrus in the patients. Conclusions: Both functional and structural impairments were evident after apparent recovery from overt hepatic encephalopathy, demonstrating that brain dysfunction induced by hepatic encephalopathy persisted after clinical resolution and provided a basis for further evolution of the disease.

  6. Individual cerebral metabolic deficits in Alzheimer's disease and amnestic mild cognitive impairment: an FDG PET study

    Energy Technology Data Exchange (ETDEWEB)

    Del Sole, Angelo; Lecchi, Michela; Lucignani, Giovanni [Unit of Nuclear Medicine, Hospital San Paolo, Institute of Radiological Sciences, University of Milan, Milan (Italy); Clerici, Francesca; Mariani, Claudio; Maggiore, Laura [University of Milan, Center for Research and Treatment on Cognitive Dysfunctions, Institute of Clinical Neurology, Department of Clinical Sciences, ' Luigi Sacco' Hospital, Milan (Italy); Chiti, Arturo [Clinical Institute Humanitas, Nuclear Medicine Department, Milan (Italy); Mosconi, Lisa [New York University School of Medicine, Department of Psychiatry, New York, NY (United States)

    2008-07-15

    The purpose of the study was the identification of group and individual subject patterns of cerebral glucose metabolism (CMRGlu) in patients with Alzheimer's disease (AD) and with amnestic mild cognitive impairment (aMCI). [{sup 18}F]fluorodeoxyglucose positron emission tomography (PET) studies and neuropsychological tests were performed in 16 aMCI patients (ten women, age 75 {+-} 8 years) and in 14 AD patients (ten women, age 75 {+-} 9 years). Comparisons between patient subgroups and with a control population were performed using Statistical Parametric Mapping. Clusters of low CMRGlu were observed bilaterally in the posterior cingulate cortex (PCC), in the precuneus, in the inferior parietal lobule and middle temporal gyrus of AD patients. In aMCI patients, reduced CMRGlu was found only in PCC. Areas of low CMRGlu in PCC were wider in AD compared to aMCI and extended to the precuneus, while low CMRGlu was found in the lateral parietal cortex in AD but not in aMCI patients. Individual subject pattern analysis revealed that 86% of AD patients had low CMRGlu in the PCC (including the precuneus in 71%), 71% in the temporal cortex, 64% in the parietal cortex and 35% in the frontal cortex. Among the aMCI patients, 56% had low CMRGlu in the PCC, 44% in the temporal cortex, 18% in the frontal cortex and none in the parietal cortex. This study demonstrates that both AD and aMCI patients have highly heterogeneous metabolic impairment. This potential of individual metabolic PET imaging in patients with AD and aMCI may allow timely identification of brain damage on individual basis and possibly help planning tailored early interventions. (orig.)

  7. Apoptosis of the fibrocytes type 1 in the spiral ligament and blood labyrinth barrier disturbance cause hearing impairment in murine cerebral malaria

    Directory of Open Access Journals (Sweden)

    Schmutzhard Joachim

    2012-02-01

    Full Text Available Abstract Background Experimental murine malaria has been shown to result in significant hearing impairment. Microscopic evaluation of the temporal bones of these animals has revealed regular morphology of the cochlea duct. Furthermore, the known vascular pathologic changes being associated with malaria could not be found. Immunohistochemistry for ICAM1 showed a strong marking in the stria vascularis, indicating a disturbance of the endocochlear potential. The aim of this study was to evaluate the role of apoptosis and the disturbance of the blood labyrinth barrier in the murine malaria associated hearing impairment. Methods The temporal bones of seven mice with cerebral malaria-four with hearing impairment, three without hearing impairment-were evaluated with immunohistochemistry for cleaved caspase 3 to detect apoptosis and connexin 26, a gap junction protein being a cornerstone in the endocochlear potassium recirculation. Furthermore five animals with cerebral malaria were treated with Evans blue prior to sacrification to detect disturbances of the blood labyrinth barrier. Results Cleaved caspase 3 could clearly be detected by immunohistochemistry in the fibrocytes of the spiral ligament, more intensively in animals with hearing impairment, less intensively in those without. Apoptosis signal was equally distributed in the spiral ligament as was the connexin 26 gap junction protein. The Evans blue testing revealed a strong signal in the malaria animals and no signal in the healthy control animals. Conclusion Malfunction of the fibrocytes type 1 in the spiral ligament and disruption of the blood labyrinth barrier, resulting in a breakdown of the endocochlear potential, are major causes for hearing impairment in murine cerebral malaria.

  8. Focal cerebral ischemia impairs motivation in a progressive FR schedule of reinforcement in mice.

    Science.gov (United States)

    Linden, J; Plumier, J-C; Fassotte, L; Ferrara, A

    2015-02-15

    Characterization of functional outcome in animal stroke models is essential to improve preclinical drug screenings. Operant procedures showed promising results for the identification of long-lasting functional deficits. In particular, a suppression of lever-pressing in high ratio schedules has been consistently found in rodent models of ischemic stroke. In the present work, we attempted to replicate these isolated observations, by submitting C57Bl/6J mice to a progressive fixed-ratio schedule of reinforcement three weeks after MCAO or sham surgery. Results showed a significant lever-pressing impairment in the MCAO group. Motivational factors (longer post-reinforcement pause, lesser appeal for food rewards) seemed accountable for the deficit, while motor abilities appeared preserved. These findings resemble fatigue-like states experienced by stroke survivors and may be used as long-term measures of behavioral outcome following experimental stroke.

  9. Safety and feasibility of countering neurological impairment by intravenous administration of autologous cord blood in cerebral palsy

    Directory of Open Access Journals (Sweden)

    Lee Young-Ho

    2012-03-01

    Full Text Available Abstract Backgrounds We conducted a pilot study of the infusion of intravenous autologous cord blood (CB in children with cerebral palsy (CP to assess the safety and feasibility of the procedure as well as its potential efficacy in countering neurological impairment. Methods Patients diagnosed with CP were enrolled in this study if their parents had elected to bank their CB at birth. Cryopreserved CB units were thawed and infused intravenously over 10~20 minutes. We assessed potential efficacy over 6 months by brain magnetic resonance imaging (MRI-diffusion tensor imaging (DTI, brain perfusion single-photon emission computed tomography (SPECT, and various evaluation tools for motor and cognitive functions. Results Twenty patients received autologous CB infusion and were evaluated. The types of CP were as follows: 11 quadriplegics, 6 hemiplegics, and 3 diplegics. Infusion was generally well-tolerated, although 5 patients experienced temporary nausea, hemoglobinuria, or urticaria during intravenous infusion. Diverse neurological domains improved in 5 patients (25% as assessed with developmental evaluation tools as well as by fractional anisotropy values in brain MRI-DTI. The neurologic improvement occurred significantly in patients with diplegia or hemiplegia rather than quadriplegia. Conclusions Autologous CB infusion is safe and feasible, and has yielded potential benefits in children with CP.

  10. Parent and professional reports of the quality of life of children with cerebral palsy and associated intellectual impairment.

    Science.gov (United States)

    White-Koning, Melanie; Grandjean, Hélène; Colver, Allan; Arnaud, Catherine

    2008-08-01

    To examine parent-professional agreement in proxy-reports of child quality of life (QoL) and the factors associated with low child QoL in children with cerebral palsy (CP) and associated intellectual impairment. Professional (teacher, therapist, or residential carer) and parent reports of QoL for 204 children (127 males, 77 females, mean age 10 y 4 mo [SD 1y 6mo]; range 8-12 y) with CP and IQprofessional agreement was studied using correlation and mean differences; multilevel logistic regression was used to determine factors influencing QoL reports and agreement. The mean parent-reported scores of child QoL were significantly higher than the professional reports in the Psychological well-being domain and significantly lower for Social support. The average frequency of disagreement (parent-professional difference >0.5SD of scores) over all domains was 62%. High levels of stress in parenting negatively influenced parent reports of child QoL compared with professional reports, while child pain was associated with professionals rating lower than parents. Proxies do not always agree when reporting the QoL of children with severe disabilities. Parental well-being and child pain should be taken into account in the interpretation of QoL reports in such children.

  11. Intracerebroventricular administration of N-acetylaspartic acid impairs antioxidant defenses and promotes protein oxidation in cerebral cortex of rats.

    Science.gov (United States)

    Pederzolli, Carolina Didonet; Rockenbach, Francieli Juliana; Zanin, Fernanda Rech; Henn, Nicoli Taiana; Romagna, Eline Coan; Sgaravatti, Angela M; Wyse, Angela T S; Wannmacher, Clóvis M D; Wajner, Moacir; de Mattos Dutra, Angela; Dutra-Filho, Carlos S

    2009-06-01

    N-acetylaspartic acid (NAA) is the biochemical hallmark of Canavan Disease, an inherited metabolic disease caused by deficiency of aspartoacylase activity. NAA is an immediate precursor for the enzyme-mediated biosynthesis of N-acetylaspartylglutamic acid (NAAG), whose concentration is also increased in urine and cerebrospinal fluid of patients affected by CD. This neurodegenerative disorder is clinically characterized by severe mental retardation, hypotonia and macrocephaly, and generalized tonic and clonic type seizures. Considering that the mechanisms of brain damage in this disease remain not fully understood, in the present study we investigated whether intracerebroventricular administration of NAA or NAAG elicits oxidative stress in cerebral cortex of 30-day-old rats. NAA significantly reduced total radical-trapping antioxidant potential, catalase and glucose 6-phosphate dehydrogenase activities, whereas protein carbonyl content and superoxide dismutase activity were significantly enhanced. Lipid peroxidation indices and glutathione peroxidase activity were not affected by NAA. In contrast, NAAG did not alter any of the oxidative stress parameters tested. Our results indicate that intracerebroventricular administration of NAA impairs antioxidant defenses and induces oxidative damage to proteins, which could be involved in the neurotoxicity of NAA accumulation in CD patients.

  12. Cognitive impairment and transmitter-specific pre- and postsynaptic changes in the rat cerebral cortex during ageing.

    Science.gov (United States)

    Majdi, Maryam; Ribeiro-da-Silva, Alfredo; Cuello, A Claudio

    2007-12-01

    Recent studies suggest that age-related cognitive decline is correlated with an excitatory-inhibitory imbalance in synaptic discharges on pyramidal neurons. This study focuses on whether ageing and cognitive status correlates with relative numbers of excitatory and inhibitory presynaptic boutons. We investigated the density of excitatory and inhibitory presynaptic inputs across several areas of the rat cerebral cortex in young and aged male Fischer 344 rats. Aged animals were segregated into aged cognitively impaired (AI) and aged cognitively unimpaired (AU) groups using the Morris water maze. We applied immunohistochemistry to reveal the majority of excitatory and inhibitory presynaptic boutons captured with confocal microscopy and quantitative image analysis. A gradual decline in the density of excitatory and inhibitory presynaptic boutons occurred from young to AU to AI animals; however, the ratios of excitatory to inhibitory presynaptic bouton densities were not significantly altered. We further investigated the density of receptor scaffolding proteins representing key excitatory and inhibitory receptor postsynaptic sites, using antibodies against specific markers of excitatory and inhibitory postsynaptic densities, respectively. Significant changes in the ratios of excitatory to inhibitory postsynaptic densities were observed only in AI compared to young rats.

  13. The relation of regional cerebral perfusion and atrophy in mild cognitive impairment (MCI) and early Alzheimer's dementia.

    Science.gov (United States)

    Luckhaus, Christian; Cohnen, Mathias; Flüss, Michael Oliver; Jänner, Michaela; Grass-Kapanke, Brigitte; Teipel, Stefan J; Grothe, Michel; Hampel, Harald; Peters, Oliver; Kornhuber, Johannes; Maier, Wolfgang; Supprian, Tillmann; Gaebel, Wolfgang; Mödder, Ulrich; Wittsack, Hans-Jörg

    2010-07-30

    The spatial and temporal relations between regional cerebral blood flow (rCBF) and brain volume (rVOL) changes in incipient and early Alzheimer's dementia (AD) are not fully understood. The participants comprised 30 subjects with mild cognitive impairment (MCI) and 15 with mild AD who were examined using structural and perfusion-weighted magnetic resonance imaging (MRI) at 1.5 Tesla. Hippocampus and amygdala volumes were measured by manual volumetry. A region-of-interest co-localisation method was used to calculate rCBF values. DNA samples were genotyped for apolipoprotein E (APO E). In comparisons of AD with MCI, rCBF was reduced in the posterior cingulum only, while profound rVOL reductions occurred in both right and left amygdala and in the right hippocampus, and as a trend, in the left hippocampus. Brain volumes of the hippocampus and the amygdala were uncorrelated with the respective rCBF variables in both MCI and AD. Hippocampal but not amygdalar volumes were associated with presence of one or two APOE epsilon4 alleles in MCI and mild AD, while there was no association of APOE epsilon4 allele with rCBF. These data support earlier indications that rCBF and rVOL changes are at least partly dissociated in the early pathogenesis of AD and heterogeneously associated with the APOE risk allele. The data also support the concept of functional compensatory brain activation and the diaschisis hypothesis as relevant in incipient and early AD.

  14. Oral Cnm-positive Streptococcus Mutans Expressing Collagen Binding Activity is a Risk Factor for Cerebral Microbleeds and Cognitive Impairment

    Science.gov (United States)

    Watanabe, Isao; Kuriyama, Nagato; Miyatani, Fumitaro; Nomura, Ryota; Naka, Shuhei; Nakano, Kazuhiko; Ihara, Masafumi; Iwai, Komei; Matsui, Daisuke; Ozaki, Etsuko; Koyama, Teruhide; Nishigaki, Masaru; Yamamoto, Toshiro; Tamura, Aiko; Mizuno, Toshiki; Akazawa, Kentaro; Takada, Akihiro; Takeda, Kazuo; Yamada, Kei; Nakagawa, Masanori; Tanaka, Tokutaro; Kanamura, Narisato; Friedland, Robert P.; Watanabe, Yoshiyuki

    2016-01-01

    Cerebral microbleeds (CMBs) are an important risk factor for stroke and dementia. We have shown that the collagen binding surface Cnm protein expressed on cnm-positive Streptococcus mutans is involved in the development of CMBs. However, whether the collagen binding activity of cnm-positive S. mutans is related to the nature of the CMBs or to cognitive impairment is unclear. Two-hundred seventy nine community residents (70.0 years) were examined for the presence or absence of cnm-positive S. mutans in the saliva by PCR and collagen binding activity, CMBs, and cognitive function were evaluated. Cnm-positive S. mutans was detected more often among subjects with CMBs (p CMBs was significantly higher (odds ratio = 14.3) in the group with S. mutans expressing collagen binding activity, as compared to the group without that finding. Deep CMBs were more frequent (67%) and cognitive function was lower among subjects with cnm-positive S. mutans expressing collagen binding activity. This work supports the role of oral health in stroke and dementia and proposes a molecular mechanism for the interaction. PMID:27934941

  15. Enhanced large conductance K+ channel activity contributes to the impaired myogenic response in the cerebral vasculature of Fawn Hooded Hypertensive rats

    Science.gov (United States)

    Pabbidi, Mallikarjuna R.; Mazur, Olga; Fan, Fan; Farley, Jerry M.; Gebremedhin, Debebe; Harder, David R.

    2014-01-01

    Recent studies have indicated that the myogenic response (MR) in cerebral arteries is impaired in Fawn Hooded Hypertensive (FHH) rats and that transfer of a 2.4 megabase pair region of chromosome 1 (RNO1) containing 15 genes from the Brown Norway rat into the FHH genetic background restores MR in a FHH.1BN congenic strain. However, the mechanisms involved remain to be determined. The present study examined the role of the large conductance calcium-activated potassium (BK) channel in impairing the MR in FHH rats. Whole-cell patch-clamp studies of cerebral vascular smooth muscle cells (VSMCs) revealed that iberiotoxin (IBTX; BK inhibitor)-sensitive outward potassium (K+) channel current densities are four- to fivefold greater in FHH than in FHH.1BN congenic strain. Inside-out patches indicated that the BK channel open probability (NPo) is 10-fold higher and IBTX reduced NPo to a greater extent in VSMCs isolated from FHH than in FHH.1BN rats. Voltage sensitivity of the BK channel is enhanced in FHH as compared with FHH.1BN rats. The frequency and amplitude of spontaneous transient outward currents are significantly greater in VSMCs isolated from FHH than in FHH.1BN rats. However, the expression of the BK-α and -β-subunit proteins in cerebral vessels as determined by Western blot is similar between the two groups. Middle cerebral arteries (MCAs) isolated from FHH rats exhibited an impaired MR, and administration of IBTX restored this response. These results indicate that there is a gene on RNO1 that impairs MR in the MCAs of FHH rats by enhancing BK channel activity. PMID:24464756

  16. Abnormal white matter tractography of visual pathways detected by high-angular-resolution diffusion imaging (HARDI) corresponds to visual dysfunction in cortical/cerebral visual impairment

    OpenAIRE

    Bauer, Corinna M.; Heidary, Gena; Koo, Bang-Bon; Killiany, Ronald J.; Bex, Peter; Merabet, Lotfi B.

    2014-01-01

    Cortical (cerebral) visual impairment (CVI) is characterized by visual dysfunction associated with damage to the optic radiations and/or visual cortex. Typically it results from pre- or perinatal hypoxic damage to postchiasmal visual structures and pathways. The neuroanatomical basis of this condition remains poorly understood, particularly with regard to how the resulting maldevelopment of visual processing pathways relates to observations in the clinical setting. We report our investigation...

  17. Mechanisms of cognitive impairment in cerebral small vessel disease: multimodal MRI results from the St George's cognition and neuroimaging in stroke (SCANS study.

    Directory of Open Access Journals (Sweden)

    Andrew J Lawrence

    Full Text Available Cerebral small vessel disease (SVD is a common cause of vascular cognitive impairment. A number of disease features can be assessed on MRI including lacunar infarcts, T2 lesion volume, brain atrophy, and cerebral microbleeds. In addition, diffusion tensor imaging (DTI is sensitive to disruption of white matter ultrastructure, and recently it has been suggested that additional information on the pattern of damage may be obtained from axial diffusivity, a proposed marker of axonal damage, and radial diffusivity, an indicator of demyelination. We determined the contribution of these whole brain MRI markers to cognitive impairment in SVD. Consecutive patients with lacunar stroke and confluent leukoaraiosis were recruited into the ongoing SCANS study of cognitive impairment in SVD (n = 115, and underwent neuropsychological assessment and multimodal MRI. SVD subjects displayed poor performance on tests of executive function and processing speed. In the SVD group brain volume was lower, white matter hyperintensity volume higher and all diffusion characteristics differed significantly from control subjects (n = 50. On multi-predictor analysis independent predictors of executive function in SVD were lacunar infarct count and diffusivity of normal appearing white matter on DTI. Independent predictors of processing speed were lacunar infarct count and brain atrophy. Radial diffusivity was a stronger DTI predictor than axial diffusivity, suggesting ischaemic demyelination, seen neuropathologically in SVD, may be an important predictor of cognitive impairment in SVD. Our study provides information on the mechanism of cognitive impairment in SVD.

  18. PI3K/Akt signal pathway involved in the cognitive impairment caused by chronic cerebral hypoperfusion in rats.

    Directory of Open Access Journals (Sweden)

    Yi Shu

    Full Text Available Chronic cerebral hypoperfusion (CCH is a common pathophysiological state that usually occurs in conditions such as vascular dementia and Alzheimer's disease, both of which are characterized by cognitive impairment. In previous studies we found that learning capacity and memory were gradually impaired with CCH, which altered the expression of synaptophysin, microtubule associated protein-2, growth associated protein-43, brain-derived neurotrophic factor, nerve growth factor, N-methyl-D-aspartate receptor subunit 1, cAMP response element-binding protein and tau hyperphosphorylation in the hippocampus. However, the molecular basis of cognitive impairment in CCH remains obscure. Here we explore the hypothesis that the phosphoinositide 3-kinase (PI3K/protein kinase B (Akt signal pathway is involved in this type of cognitive impairment. In order to determine if the expression of PI3K, Akt and phosphorylated Akt (p-Akt proteins are altered at different stages of CCH with differing levels of cognitive impairment. we performed permanent, bilateral occlusion of the common carotid arteries (2-VO to induce CCH. Adult male SD rats were randomly divided into sham-operated group, 2-VO 1 week group, 2-VO 4 weeks group and 2-VO 8 weeks group. Behavior tests were utilized to assess cognitive abilities, while western blots were utilized to evaluate protein expression. Rats in the 2-VO groups spent less time exploring novel objects than those in the sham-operated group, and the discrimination ratio of the 2-VO 8 weeks group and the sham-operated group were higher than chance (0.50. Escape latencies in the Morris water maze task in the 2-VO 1 week group were longer than those in the sham-operated group on day 4 and day 5, while escape latencies in the 2-VO 4 weeks group were longer than those in the sham-operated group from day 3 to day 5. Escape latencies in 2-VO 8 weeks group were longer than those in the sham-operated group from day 2 to day 5. NE (northeast

  19. Cerebral blood flow measurement in patients with impaired consciousness: usefulness of {sup 99m}Tc-HMPAO single-photon emission tomography in clinical practice

    Energy Technology Data Exchange (ETDEWEB)

    Chang Chia-Cheng; Kuwana, Nobumasa; Noji, Masato; Tanabe, Yutaka; Koike, Y. [Department of Neurosurgery, Yokohama Minami Kyosai Hospital, Yokohama (Japan); Ikegami, Tadashi [Department of Radiology, Yokohama Minami Kyosai Hospital, Yokohama (Japan)

    1998-09-01

    The relationship between impairment of consciousness and quantitative cerebral blood flow (CBF) was investigated. The mean CBF of the whole brain was measured by the Patlak-plot method using technetium-99m hexamethylpropylene amine oxime single-photon emission tomography ({sup 99m}Tc-HMPAO SPET) in patients with the following diseases: cerebral infarction, intraparenchymal haemorrhage, subarachnoid haemorrhage, brain tumour and cerebral contusion. The clinical symptoms were evaluated according to the severity of impaired consciousness, aphasia and dementia. Four hundred and eighty-five CBF measurements were performed. Patients with alert consciousness showed an age-related decline in mean CBF. Patients with aphasia showed a significant reduction in mean CBF compared with those without aphasia. Impaired consciousness was proportional to reduction in mean CBF regardless of types of pathology, and the size of lesion did not influence the mean CBF. Patients with dementia showed a significant reduction in mean CBF proportional to the severity of dementia. The quantitative measurement of CBF using {sup 99m}Tc-HMPAO SPET is reliable in clinical evaluations. (orig.) With 3 tabs., 10 refs.

  20. Differences in functional brain connectivity alterations associated with cerebral amyloid deposition in amnestic mild cognitive impairment

    Directory of Open Access Journals (Sweden)

    Dahyun eYi

    2015-02-01

    Full Text Available Despite potential implications for the early detection of impending AD, very little is known about the differences of large scale brain networks between amnestic MCI (aMCI with high cerebral amyloid beta protein (Aβ deposition (i.e., aMCI+ and aMCI with no or very little Aβ deposition (i.e., aMCI-. We first aimed to extend the current literature on altering intrinsic functional connectivity (FC of the default mode network (DMN and salience network (SN from CN to AD dementia. Second, we further examined the differences of the DMN and the SN between aMCI-, aMCI+, and CN. Forty-three older adult (12 CN, 10 aMCI+, 10 aMCI-, and 11 AD dementia subjects were included. All participants received clinical and neuropsychological assessment, resting state functional MRI, structural MRI, and Pittsburgh compound-B-PET scans. FC data were preprocessed using Multivariate Exploratory Linear Optimized Decomposition into Independent Components of FSL. Group comparisons were carried out using the dual-regression approach. In addition, to verify presence of grey matter (GM volume changes with intrinsic functional network alterations, Voxel Based Morphometry was performed on the acquired T1-weighted data. As expected, AD dementia participants exhibited decreased FC in the DMN compared to CN (in precuneus and cingulate gyrus. The degree of alteration in the DMN in aMCI+ compared to CN was intermediate to that of AD. In contrast, aMCI- exhibited increased FC in the DMN compared to CN (in precuneus as well as aMCI+. In terms of the SN, aMCI- exhibited decreased FC compared to both CN and aMCI+ particularly in the inferior frontal gyrus. FC within the SN in aMCI+ and AD did not differ from CN. Compared to CN, aMCI- showed atrophy in bilateral superior temporal gyri whereas aMCI+ showed atrophy in right precuneus. The results indicate that despite of the similarity in cross-sectional cognitive features aMCI- has quite different functional brain connectivity compared to

  1. Beta adrenergic overstimulation impaired vascular contractility via actin-cytoskeleton disorganization in rabbit cerebral artery.

    Directory of Open Access Journals (Sweden)

    Hyoung Kyu Kim

    Full Text Available BACKGROUND AND PURPOSE: Beta adrenergic overstimulation may increase the vascular damage and stroke. However, the underlying mechanisms of beta adrenergic overstimulation in cerebrovascular dysfunctions are not well known. We investigated the possible cerebrovascular dysfunction response to isoproterenol induced beta-adrenergic overstimulation (ISO in rabbit cerebral arteries (CAs. METHODS: ISO was induced in six weeks aged male New Zealand white rabbit (0.8-1.0 kg by 7-days isoproterenol injection (300 μg/kg/day. We investigated the alteration of protein expression in ISO treated CAs using 2DE proteomics and western blot analysis. Systemic properties of 2DE proteomics result were analyzed using bioinformatics software. ROS generation and following DNA damage were assessed to evaluate deteriorative effect of ISO on CAs. Intracellular Ca(2+ level change and vascular contractile response to vasoactive drug, angiotensin II (Ang II, were assessed to evaluate functional alteration of ISO treated CAs. Ang II-induced ROS generation was assessed to evaluated involvement of ROS generation in CA contractility. RESULTS: Proteomic analysis revealed remarkably decreased expression of cytoskeleton organizing proteins (e.g. actin related protein 1A and 2, α-actin, capping protein Z beta, and vimentin and anti-oxidative stress proteins (e.g. heat shock protein 9A and stress-induced-phosphoprotein 1 in ISO-CAs. As a cause of dysregulation of actin-cytoskeleton organization, we found decreased level of RhoA and ROCK1, which are major regulators of actin-cytoskeleton organization. As functional consequences of proteomic alteration, we found the decreased transient Ca(2+ efflux and constriction response to angiotensin II and high K(+ in ISO-CAs. ISO also increased basal ROS generation and induced oxidative damage in CA; however, it decreased the Ang II-induced ROS generation rate. These results indicate that ISO disrupted actin cytoskeleton proteome network

  2. Blood flow autoregulation in pedicled flaps

    DEFF Research Database (Denmark)

    Bonde, Christian T; Holstein-Rathlou, Niels-Henrik; Elberg, Jens J

    2009-01-01

    INTRODUCTION: Clinical work on the blood perfusion in skin and muscle flaps has suggested that some degree of blood flow autoregulation exists in such flaps. An autoregulatory mechanism would enable the flap to protect itself from changes in the perfusion pressure. The purpose of the present study...... was to evaluate if, and to what extent, a tissue flap could compensate a reduction in blood flow due to an acute constriction of the feed artery. Further, we wanted to examine the possible role of smooth muscle L-type calcium channels in the autoregulatory mechanism by pharmacological intervention with the L......-type calcium channel blocker nimodipine and the vasodilator papaverine. MATERIAL AND METHODS: Pedicled flaps were raised in pigs. Flow in the pedicle was reduced by constriction of the feed artery (n=34). A transit time flow probe measured the effect on blood flow continuously. Following this, three different...

  3. Frequency domain analysis of noise in autoregulated gene circuits

    OpenAIRE

    Simpson, Michael L.; Cox, Chris D.; Sayler, Gary S.

    2003-01-01

    We describe a frequency domain technique for the analysis of intrinsic noise within negatively autoregulated gene circuits. This approach is based on the transfer function around the feedback loop (loop transmission) and the equivalent noise bandwidth of the system. The loop transmission, T, is shown to be a determining factor of the dynamics and the noise behavior of autoregulated gene circuits, and this T-based technique provides a simple and flexible method for the analysis of noise arisin...

  4. Efficacy of CDP and ENG in Detecting Balance Impairment Associated With Cerebral White Matter Changes.

    Science.gov (United States)

    Urban, Matthew J; Sataloff, Robert T

    2016-10-01

    To examine the relationship between white matter changes (WMCs) and abnormal balance test results on computerized dynamic posturography (CDP) and electronystagmography (ENG). Also, to compare the utility of CDP with ENG for this purpose. Retrospective case review. Tertiary care referral center. A retrospective review of 137 subjects was conducted. The CDP and ENG results were compared between patients with (80) and without (57) WMCs as detected byT2/fluid attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI). CDP analysis consisted of both sensory organization test (SOT) and motor control test (MCT) results, and ENG analysis included positional, oculomotor, and bithermal caloric testing. Multivariate logistic regression was performed to control for age and hearing loss discrepancies between the two groups. Ninety three percent of patients with WMCs had an abnormal CDP result, as compared with 44% of patients lacking WMCs (p ENG, as did 81% of patients without WMCs (p = 0.435). Multivariate regression analysis maintained that an abnormal CDP result was significantly associated with WMCs when controlling for age and hearing loss (p ENG. Hence, CDP may be a better study to identify and document patients who have balance dysfunction associated with this central finding. Such identification will permit additional evaluation and treatment based on objective confirmation of balance dysfunction, in this group of balance-impaired subjects who may have normal ENG's.

  5. 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...... haemodynamics' includes cerebral blood flow (CBF), cerebral blood flow velocity, and cerebral blood volume (CBV). Therapy aimed at changing vascular anatomy is not available. Therefore, prevention of disturbances in CBF and CBV is pivotal. However, continuous monitoring of CBF and CBV is still unavailable...... for clinical use. Tissue oxygenation may be used as a surrogate for CBF, although precision is still questionable. General knowledge of the regulation of CBF and CBV is important. Although this knowledge is still incomplete, especially regarding autoregulation and the exact role of CBV, it is still useful...

  6. Compromised cerebrovascular modulation in chronic anxiety: evidence from cerebral blood flow velocity measured by transcranial Doppler sonography

    Institute of Scientific and Technical Information of China (English)

    Hong-Liang Zhang; Zhen-Ni Guo; Ge Yang; Le Yang; Ke Han; Jiang Wu; Yingqi Xing; Yi Yang

    2012-01-01

    Objective Cerebral autoregulation (CA) is the mechanism by which constant cerebral blood flow is maintained despite changes in cerebral perfusion pressure.CA can be evaluated by dynamic monitoring of cerebral blood flow velocity (CBFV) with transcranial Doppler sonography (TCD).The present study aimed to explore CA in chronic anxiety.Methods Subjects with Hamilton anxiety scale scores ≥14 were enrolled and the dynamic changes of CBFV in response to an orthostatic challenge were investigated using TCD.Results In both the anxious and the healthy subjects,the mean CBFV was significantly lower in the upright position than when supine.However,the CBFV changes from supine to upright differed between the anxious and the healthy groups.Anxious subjects showed more pronounced decreases in CBFV with abrupt standing.Conclusion Our results indicate that cerebrovascular modulation is compromised in chronic anxiety; anxious subjects have some insufficiency in maintaining cerebral perfusion after postural change.Given the fact that anxiety and impaired CA are associated with cardiovascular disease,early ascertainment of compromised cerebrovascular modulation using TCD might suggest interventional therapies in the anxious population,and improve the primary prevention of cardiovascular disease.

  7. Ginsenoside Reduces Cognitive Impairment During Chronic Cerebral Hypoperfusion Through Brain-Derived Neurotrophic Factor Regulated by Epigenetic Modulation.

    Science.gov (United States)

    Wan, Qun; Ma, Xue; Zhang, Zhi-Jun; Sun, Ting; Xia, Feng; Zhao, Gang; Wu, Yu-Mei

    2016-03-28

    Increased expression of brain-derived neurotrophic factor (BDNF) has been associated with memory-enhancing and neuroprotective properties of some drugs under chronic cerebral hypoperfusion (CCH) condition. Ginsenoside Rd (GSRd), one of the main active ingredients in Panax ginseng, is widely used for brain protection. However, it is poorly understood whether epigenetic mechanisms implied in the BDNF modulation after GSRd treatment for CCH remain elusive. Here, we investigated the neuroprotective effects of GSRd and the involved mechanisms. We demonstrated that GSRd administration ameliorated CCH-induced impairment of learning and memory behaviors, evidenced by decreased escape latency and increased number of crossing the platform in Morris water maze test. This improvement was associated with promoted neuron survival and increased BDNF expression in the hippocampus and prefrontal cortex of CCH mice. GSRd improved neuron survival and decreased neuron apoptosis and the level of caspase-3 under oxygen-glucose deprivation/reoxygenation (OGD/R) by upregulation of BDNF as well as in vitro. The levels of acetylated histone H3 (Ac-H3) and histone deacetylase (histone deacetylase 2 (HDAC2)) were altered under OGD/R in a time-dependent manner, and GSRd reestablished the balance between Ac-H3 and HDAC2 which resulted in upregulation of BDNF and increased neuron survival. MS-275, an inhibitor of class I HDACs, abolished the levels of Ac-H3 at the bdnf promoters and enhanced upregulation of BDNF after GSRd administration, suggesting a synergistic effect between GSRd and MS-275. All the data suggested that GSRd provided neuroprotection by epigenetic modulation which accounted for the regulation of BDNF in CCH mice.

  8. Uptake of glutamate is impaired in the cortical penumbra of the rat following middle cerebral artery occlusion

    DEFF Research Database (Denmark)

    Bruhn, Torben; Christensen, Thomas; Diemer, Nils Henrik

    2003-01-01

    By using microdialysis extraction of (3)H-D-aspartate and concomitant recordings of extracellular direct current (DC) potentials, the effect of middle cerebral artery occlusion (MCAO) was studied continuously over a period of 100 min in the cerebral cortex of rats. From analysis of the DC potenti...

  9. 脑瘫患儿的视觉功能综合评估%Comprehensive visual impairment evaluation for cerebral palsy children

    Institute of Scientific and Technical Information of China (English)

    王平; 张惠佳; 覃容; 唐景; 罗毅

    2015-01-01

    目的:采用多项客观指标综合评估脑瘫患儿视觉功能,探讨脑瘫患儿的视觉障碍的临床特点。方法:对43例86眼眼部有视觉障碍脑瘫患儿进行眼追随实验、视动性眼震、屈光、眼底、斜视、图形视觉诱发电位(pattern visual evoked potential,P-VEP)及头颅磁共振成像( magnetic resonance imaging,MRI)等客观指标检查;对脑瘫患儿的视觉功能进行综合评估,分析不同性质脑瘫患儿的视觉障碍发生特点和可能机制。结果:(1)43例86眼合并视觉障碍患儿中,25例50眼(58.1%)脑瘫患儿发现屈光不正;24例48眼(55.8%)患儿存在斜视;12例24眼(27.9%)患儿伴有眼球震颤;19例38眼(44.2%)眼底视神经萎缩或者发育异常;35例70眼(81.4%)患儿VEP表现为异常;其中痉挛型脑瘫患儿中视觉障碍发生率与其他各组差异有显著统计学意义(P0.05),皮质损害脑瘫患儿无眼球震颤发生。结论:脑瘫患儿的视觉障碍在临床常见,各类型脑瘫患儿视觉障碍发生率有差别并有着不同临床特点;客观综合指标评估方法对脑瘫患儿视觉功能评估准确可靠。%Abstract•AlM: To evaluate the visual impairment in cerebral palsy children with series objective indicators, and conclude their clinical features of visual function.• METHODS: Objective tests including following pursuing test, optokinetic nystagmus(OKN) drum test, refractive error examination, fundus examination, ocular deviation examination, pattern visual evoked potential ( P-VEP ) tests and brain magnetic resonance imaging ( MRl) were carried out in 43 cerebral palsy children ( 86 eyes ) with ocular visual dysfunction; The visual impairment data of the cerebral palsy children were collected, and the clinical features and possible mechanism were analyzed.•RESULTS: 1. Of the 43 cerebral palsy children ( 86 eyes) with the visual impairment presented diversified, 25 ( 50 eyes, 58. 1%) of refractive error, 24 ( 48 eyes

  10. Information Processing in Auto-regulated Systems

    Directory of Open Access Journals (Sweden)

    Karl Javorszky

    2003-06-01

    Full Text Available Abstract: We present a model of information processing which is based on two concurrent ways of describing the world, where a description in one of the languages limits the possibilities for realisations in the other language. The two describing dimensions appear in our common sense as dichotomies of perspectives: subjective - objective; diversity - similarity; individual - collective. We abstract from the subjective connotations and treat the test theoretical case of an interval on which several concurrent categories can be introduced. We investigate multidimensional partitions as potential carriers of information and compare their efficiency to that of sequenced carriers. We regard the same assembly once as a contemporary collection, once as a longitudinal sequence and find promising inroads towards understanding information processing by auto-regulated systems. Information is understood to point out that what is the case from among alternatives, which could be the case. We have translated these ideas into logical operations on the set of natural numbers and have found two equivalence points on N where matches between sequential and commutative ways of presenting a state of the world can agree in a stable fashion: a flip-flop mechanism is envisioned. By following this new approach, a mathematical treatment of some poignant biomathematical problems is allowed. Also, the concepts presented in this treatise may well have relevance and applications within the information processing and the theory of language fields.

  11. Molecular mechanisms controlling legume autoregulation of nodulation.

    Science.gov (United States)

    Reid, Dugald E; Ferguson, Brett J; Hayashi, Satomi; Lin, Yu-Hsiang; Gresshoff, Peter M

    2011-10-01

    High input costs and environmental pressures to reduce nitrogen use in agriculture have increased the competitive advantage of legume crops. The symbiotic relationship that legumes form with nitrogen-fixing soil bacteria in root nodules is central to this advantage. Understanding how legume plants maintain control of nodulation to balance the nitrogen gains with their energy needs and developmental costs will assist in increasing their productivity and relative advantage. For this reason, the regulation of nodulation has been extensively studied since the first mutants exhibiting increased nodulation were isolated almost three decades ago. Nodulation is regulated primarily via a systemic mechanism known as the autoregulation of nodulation (AON), which is controlled by a CLAVATA1-like receptor kinase. Multiple components sharing homology with the CLAVATA signalling pathway that maintains control of the shoot apical meristem in arabidopsis have now been identified in AON. This includes the recent identification of several CLE peptides capable of activating nodule inhibition responses, a low molecular weight shoot signal and a role for CLAVATA2 in AON. Efforts are now being focused on directly identifying the interactions of these components and to identify the form that long-distance transport molecules take.

  12. Fluoxetine ameliorates cognitive impairments induced by chronic cerebral hypoperfusion via down-regulation of HCN2 surface expression in the hippocampal CA1 area in rats.

    Science.gov (United States)

    Luo, Pan; Zhang, Xiaoxue; Lu, Yun; Chen, Cheng; Li, Changjun; Zhou, Mei; Lu, Qing; Xu, Xulin; Shen, Guanxin; Guo, Lianjun

    2016-01-01

    Chronic cerebral hypoperfusion (CCH) causes cognitive impairments and increases the risk of Alzheimer's disease (AD) and vascular dementia (VD) through several biologically plausible pathways, yet the underlying neurobiological mechanisms are still poorly understood. In this study, we investigated whether fluoxetine, a selective serotonin reuptake inhibitor (SSRI), could play a neuroprotective role against chronic cerebral hypoperfusion injury and to clarify underlying mechanisms of its efficacy. Rats were subjected to permanent bilateral occlusion of the common carotid arteries (two-vessel occlusion, 2VO). Two weeks later, rats were treated with 30 mg/kg fluoxetine (intragastric injection, i.g.) for 6 weeks. Cognitive function was evaluated by Morris water maze (MWM) and novel objects recognition (NOR) test. Long-term potentiation (LTP) was used to address the underlying synaptic mechanisms. Western blotting was used to quantify the protein levels. Our results showed that fluoxetine treatment significantly improved the cognitive impairments caused by 2VO, accompanied with a reversion of 2VO-induced inhibitory of LTP. Furthermore, 2VO caused an up-regulation of hyperpolarization-activated cyclic nucleotide-gated channel 2 (HCN2) surface expressions in the hippocampal CA1 area and fluoxetine also effectively recovered the disorder of HCN2 surface expressions, which may be a possible mechanism that fluoxetine treatment ameliorates cognitive impairments in rats with CCH.

  13. Impaired motor planning and motor imagery in children with unilateral spastic cerebral palsy: challenges for the future of pediatric rehabilitation.

    NARCIS (Netherlands)

    Steenbergen, B.; Jongbloed-Pereboom, M.; Spruijt, S.; Gordon, A.M.

    2013-01-01

    Compromised action performance is one of the most characteristic features of children with unilateral spastic cerebral palsy (USCP). Current rehabilitation efforts predominantly aim to improve the capacity and performance of the affected arm. Recent evidence, however, suggests that compromised motor

  14. Pressure Autoregulation Measurement Techniques in Adult TBI, Part I: A Scoping Review of Intermittent/Semi-Intermittent Methods.

    Science.gov (United States)

    Zeiler, Frederick Adam; Donnelly, Joseph; Calviello, Leanne; Menon, David; Smieleweski, Peter; Czosnyka, Marek

    2017-06-24

    To perform a systematic, scoping review of commonly described intermittent/semi-intermittent autoregulation measurement techniques in adult TBI. Nine separate systematic reviews were conducted for each intermittent technique: Computed tomographic perfusion (CTP)/Xenon-CT (Xe-CT), positron emission tomography (PET), magnetic resonance imaging (MRI), arterio-venous difference in oxygen (AVDO2) technique, thigh cuff deflation technique (TCDT), transient hyperemic response test (THRT), orthostatic hypotension test (OHT), mean flow index (Mx) and transfer function ARI (TF-ARI). MEDLINE, BIOSIS, EMBASE, Global Health, Scopus, Cochrane Library (inception to December 2016) and reference lists of relevant articles were searched. A two-tier filter of references was conducted. The total number of articles utilizing each of the 9 searched techniques for intermittent/semi-intermittent autoregulation techniques in adult TBI were: CTP/Xe-CT (10), PET (6), MRI (0), AVDO2 (10), autoregulation index (ARI) based TCDT (9), THRT (6), OHT (3), Mx (17) and TF-ARI (6). The premise behind all of the intermittent techniques is manipulation of systemic blood pressure/blood volume via either chemical (such as vasopressors) or mechanical (such as thigh cuffs or carotid compression) means. Exceptionally, Mx and TF-ARI are based on spontaneous fluctuations of CPP or MAP. The method for assessing the cerebral circulation during these manipulations varies, with both imaging based techniques and TCD utilized. Despite the limited literature for intermittent/semi-intermittent techniques in adult TBI (minus Mx), it is important to acknowledge the availability of such tests. They have provided fundamental insight into human autoregulatory capacity, leading to the development of continuous and more commonly applied techniques in the ICU. Numerous methods of intermittent/semi-intermittent pressure autoregulation assessment in adult TBI exist, including: CTP/Xe-CT, PET, AVDO2 technique, TCDT based ARI

  15. Cerebral hemodynamics in patients with obstructive sleep apnea syndrome monitored with near-infrared spectroscopy (NIRS) during positive airways pressure (CPAP) therapy: a pilot study

    Science.gov (United States)

    Zhang, Zhongxing; Schneider, Maja; Laures, Marco; Fritschi, Ursula; Lehner, Isabella; Qi, Ming; Khatami, Ramin

    2014-03-01

    In obstructive sleep apnea syndrome (OSA) the periodic reduction or cessation of breathing due to narrowing or occlusion of the upper airway during sleep leads to daytime symptoms and increased cardiovascular risk, including stroke. The higher risk of stroke is related to the impairment in cerebral vascular autoregulation. Continuous positive airways pressure (CPAP) therapy at night is the most effective treatment for OSA. However, there is no suitable bedside monitoring method evaluating the treatment efficacy of CPAP therapy, especially to monitor the recovery of cerebral hemodynamics. NIRS is ideally suited for non-invasive monitoring the cerebral hemodynamics during sleep. In this study, we will for first time assess dynamic changes of cerebral hemodynamics during nocturnal CPAP therapy in 3 patients with OSA using NIRS. We found periodic oscillations in HbO2, HHb, tissue oxygenation index (TOI) and blood volume associated with periodic apnea events without CPAP in all OSA patients. These oscillations were gradually attenuated and finally eliminated with the stepwise increments of CPAP pressures. The oscillations were totally eliminated in blood volume earlier than in other hemodynamic parameters. These results suggested that 1) the cerebral hemodynamic oscillations induced by OSA events can effectively be attenuated by CPAP therapy, and 2) blood flow and blood volume recovered first during CPAP therapy, followed by the recovery of oxygen consumption. Our study suggested that NIRS is a useful tool to evaluate the efficacy of CPAP therapy in patients with OSA bedside and in real time.

  16. Cerebral hemodynamics after short- and long-term reduction in blood pressure in mild and moderate hypertension.

    NARCIS (Netherlands)

    Zhang, R.; Witkowski, S.; Fu, Q.; Claassen, J.A.H.R.; Levine, B.D.

    2007-01-01

    This study tested the hypothesis that acute reduction in blood pressure (BP) at the initial stage of antihypertensive therapy compromises brain perfusion and dynamic cerebral autoregulation in patients with hypertension. Cerebral blood flow velocity and BP were measured in patients with mild and mod

  17. Ten-minute umbilical cord occlusion markedly reduces cerebral blood flow and heat production in fetal sheep.

    NARCIS (Netherlands)

    Lotgering, F.K.; Bishai, J.M.; Struijk, P.C.; Blood, A.B.; Hunter, C.J.; Power, G.G.; Longo, L.D.

    2003-01-01

    OBJECTIVE: The study was undertaken to determine to what extent a 10-minute total umbilical cord occlusion affects autoregulation of cerebral blood flow and cerebral heat production in the fetus. STUDY DESIGN: In seven chronically catheterized late-gestation fetal sheep (127-131 days' gestation), we

  18. Pathogenesis of cerebral microbleeds: In vivo imaging of amyloid and subcortical ischemic small vessel disease in 226 individuals with cognitive impairment.

    Science.gov (United States)

    Park, Jae-Hyun; Seo, Sang Won; Kim, Changsoo; Kim, Geon Ha; Noh, Hyun Jin; Kim, Sung Tae; Kwak, Ki-Chang; Yoon, Uicheul; Lee, Jong Min; Lee, Jong Weon; Shin, Ji Soo; Kim, Chi Hun; Noh, Young; Cho, Hanna; Kim, Hee Jin; Yoon, Cindy W; Oh, Seung Jun; Kim, Jae Seung; Choe, Yearn Seong; Lee, Kyung-Han; Lee, Jae-Hong; Ewers, Michael; Weiner, Michael W; Werring, David J; Na, Duk L

    2013-05-01

    Cerebral microbleeds (CMBs) are a neuroimaging marker of small vessel disease (SVD) with relevance for understanding disease mechanisms in cerebrovascular disease, cognitive impairment, and normal aging. It is hypothesized that lobar CMBs are due to cerebral amyloid angiopathy (CAA) and deep CMBs are due to subcortical ischemic SVD. We tested this hypothesis using structural magnetic resonance imaging (MRI) markers of subcortical SVD and in vivo imaging of amyloid in patients with cognitive impairment. We included 226 patients: 89 with Alzheimer disease-related cognitive impairment (ADCI) and 137 with subcortical vascular cognitive impairment (SVCI). All subjects underwent amyloid imaging with [(11) C] Pittsburgh compound B (PiB) positron emission tomography, and MRI to detect CMBs and markers of subcortical SVD, including the volume of white matter hyperintensities (WMH) and the number of lacunes. Parietal and occipital lobar CMBs counts were higher in PiB(+) ADCI with moderate WMH than PiB(+) ADCI with minimal WMH, whereas PiB(-) patients with SVCI (ie, "pure" SVCI) showed both lobar and deep CMBs. In multivariate analyses of the whole cohort, WMH volume and lacuna counts were positively associated with both lobar and deep CMBs, whereas amyloid burden (PiB) was only associated with lobar CMBs. There was an interaction between lacuna burden and PiB retention on lobar (but not deep) CMBs (pCMBs are mainly linked to subcortical SVD, both subcortical SVD and amyloid-related pathologies (eg, CAA) contribute to the pathogenesis of lobar CMBs, at least in subjects with mixed lobar and deep CMBs. Furthermore, subcortical SVD and amyloid-related pathologies interact to increase the risk of lobar CMBs. Copyright © 2012 American Neurological Association.

  19. Cerebral hemodynamics and systemic endothelial function are already impaired in well-controlled type 2 diabetic patients, with short-term disease.

    Directory of Open Access Journals (Sweden)

    Paola Palazzo

    Full Text Available OBJECTIVE: Impaired cerebral vasomotor reactivity (VMR and flow-mediated dilation (FMD were found in selected subgroups of type 2 diabetes mellitus (T2DM patients with long-term disease. Our study aimed to evaluate cerebral hemodynamics, systemic endothelial function and sympatho-vagal balance in a selected population of well-controlled T2DM patients with short-term disease and without cardiac autonomic neuropathy (CAN. RESEARCH DESIGN AND METHODS: Twenty-six T2DM patients with short-term (4.40±4.80 years and well-controlled (HbA1C = 6.71±1.29% disease, without any complications, treated with diet and/or metformin, were consecutively recruited. Eighteen controls, comparable by sex and age, were enrolled also. RESULTS: FMD and shear rate FMD were found to be reduced in T2DM subjects with short-term disease (8.5% SD 3.5 and 2.5 SD 1.3, respectively compared to controls (15.4% SD 4.1 and 3.5 SD 1.4; p.05. CONCLUSIONS: In well-controlled T2DM patients with short-term disease cerebral hemodynamics and systemic endothelial function are altered while autonomic balance appeared to be preserved.

  20. Magnetic Resonance Imaging Quantification of Regional Cerebral Blood Flow and Cerebrovascular Reactivity to Carbon Dioxide in Normotensive and Hypertensive Rats

    Science.gov (United States)

    Leoni, Renata F.; Paiva, Fernando F.; Henning, Erica C.; Nascimento, George C.; Tannús, Alberto; de Araujo, Draulio B.; Silva, Afonso C.

    2011-01-01

    Hypertension afflicts 25% of the general population and over 50% of the elderly. In the present work, arterial spin labeling MRI was used to non-invasively quantify regional cerebral blood flow (CBF), cerebrovascular resistance and CO2 reactivity in spontaneously hypertensive rats (SHR) and in normotensive Wistar Kyoto rats (WKY), at two different ages (3 months and 10 months) and under the effects of two anesthetics, α-chloralose and 2% isoflurane (1.5 MAC). Repeated CBF measurements were highly consistent, differing by less than 10% and 18% within and across animals, respectively. Under α-chloralose, whole brain CBF at normocapnia did not differ between groups (young WKY: 61±3ml/100g/min; adult WKY: 62±4ml/100g/min; young SHR: 70±9ml/100g/min; adult SHR: 69±8ml/100g/min), indicating normal cerebral autoregulation in SHR. At hypercapnia, CBF values increased significantly, and a linear relationship between CBF and PaCO2 levels was observed. In contrast, 2% isoflurane impaired cerebral autoregulation. Whole brain CBF in SHR was significantly higher than in WKY rats at normocapnia (young SHR: 139±25ml/100g/min; adult SHR: 104±23ml/100g/min; young WKY: 55±9ml/100g/min; adult WKY: 71±19ml/100g/min). CBF values increased significantly with increasing CO2; however, there was a clear saturation of CBF at PaCO2 levels greater than 70 mmHg in both young and adult rats, regardless of absolute CBF values, suggesting that isoflurane interferes with the vasodilatory mechanisms of CO2. This behavior was observed for both cortical and subcortical structures. Under either anesthetic, CO2 reactivity values in adult SHR were decreased, confirming that hypertension, when combined with age, increases cerebrovascular resistance and reduces cerebrovascular compliance. PMID:21708273

  1. The ameliorative effects of exercise on cognitive impairment and white matter injury from blood-brain barrier disruption induced by chronic cerebral hypoperfusion in adolescent rats.

    Science.gov (United States)

    Lee, Jae-Min; Park, Jong-Min; Song, Min Kyung; Oh, Yoo Joung; Kim, Chang-Ju; Kim, Youn-Jung

    2017-01-18

    Vascular dementia is the progressive change in blood vessels that leads to neuronal injuries in vulnerable areas induced by chronic cerebral hypoperfusion (CCH). CCH induces disruption of blood-brain barrier (BBB), and this BBB disruption can initiate the cognitive impairment and white matter injury. In the present study, we evaluated the effect of treadmill exercise on the cognitive impairment, white matter injury, and BBB disruption induced by CCH. Vascular dementia was induced by permanent bilateral common carotid arteries occlusion (BCCAO) in rats. The rats in the exercise group were made to run on a treadmill for 30min once a day for 14 weeks, starting 4 weeks after birth. Our results revealed that treadmill exercise group was alleviated the cognitive impairment and myelin degradation induced by CCH. The disruption of BBB after CCH indicates degradation of occludin, zonula occluden-1 (ZO-1), and up-regulation of matrix metalloproteinases (MMPs). Treadmill exercise may provide protective effects on BBB disruption from degradation of occludin, ZO-1, and overexpression of MMP-9 after CCH. These findings suggest that treadmill exercise ameliorates cognitive impairment and white matter injury from BBB disruption induced by CCH in rats. The present study will be valuable for means of prophylactic and therapeutic intervention for patients with CCH.

  2. Stability Depends on Positive Autoregulation in Boolean Gene Regulatory Networks

    Science.gov (United States)

    Pinho, Ricardo; Garcia, Victor; Irimia, Manuel; Feldman, Marcus W.

    2014-01-01

    Network motifs have been identified as building blocks of regulatory networks, including gene regulatory networks (GRNs). The most basic motif, autoregulation, has been associated with bistability (when positive) and with homeostasis and robustness to noise (when negative), but its general importance in network behavior is poorly understood. Moreover, how specific autoregulatory motifs are selected during evolution and how this relates to robustness is largely unknown. Here, we used a class of GRN models, Boolean networks, to investigate the relationship between autoregulation and network stability and robustness under various conditions. We ran evolutionary simulation experiments for different models of selection, including mutation and recombination. Each generation simulated the development of a population of organisms modeled by GRNs. We found that stability and robustness positively correlate with autoregulation; in all investigated scenarios, stable networks had mostly positive autoregulation. Assuming biological networks correspond to stable networks, these results suggest that biological networks should often be dominated by positive autoregulatory loops. This seems to be the case for most studied eukaryotic transcription factor networks, including those in yeast, flies and mammals. PMID:25375153

  3. Rhythmic components in renal autoregulation: Nonlinear modulation phenomena

    DEFF Research Database (Denmark)

    Pavlov, A. N.; Sosnovtseva, Olga; Pavlova, O. N.;

    2009-01-01

    Autoregulation of nephron blood flow involves two oscillatory processes: the tubular-flow sensitive tubuloglomerular feedback (TGF) mechanism and the blood-pressure sensitive myogenic mechanism. Both act to regulate the diameter of the afferent arteriole, which carries blood to the nephron...

  4. Stability depends on positive autoregulation in Boolean gene regulatory networks.

    Directory of Open Access Journals (Sweden)

    Ricardo Pinho

    2014-11-01

    Full Text Available Network motifs have been identified as building blocks of regulatory networks, including gene regulatory networks (GRNs. The most basic motif, autoregulation, has been associated with bistability (when positive and with homeostasis and robustness to noise (when negative, but its general importance in network behavior is poorly understood. Moreover, how specific autoregulatory motifs are selected during evolution and how this relates to robustness is largely unknown. Here, we used a class of GRN models, Boolean networks, to investigate the relationship between autoregulation and network stability and robustness under various conditions. We ran evolutionary simulation experiments for different models of selection, including mutation and recombination. Each generation simulated the development of a population of organisms modeled by GRNs. We found that stability and robustness positively correlate with autoregulation; in all investigated scenarios, stable networks had mostly positive autoregulation. Assuming biological networks correspond to stable networks, these results suggest that biological networks should often be dominated by positive autoregulatory loops. This seems to be the case for most studied eukaryotic transcription factor networks, including those in yeast, flies and mammals.

  5. Nonlinear Analysis of Renal Autoregulation Under Broadband Forcing Conditions

    DEFF Research Database (Denmark)

    Marmarelis, V Z; Chon, K H; Chen, Y M;

    1994-01-01

    Linear analysis of renal blood flow fluctuations, induced experimentally in rats by broad-band (pseudorandom) arterial blood pressure forcing at various power levels, has been unable to explain fully the dynamics of renal autoregulation at low frequencies. This observation has suggested the possi...

  6. To autoregulate or not to autoregulate--that is no longer the question

    DEFF Research Database (Denmark)

    Greisen, Gorm

    2009-01-01

    In the late 1970s, high cerebral blood flow was perceived as a cause of intracranial hemorrhage in the preterm infant. Intracranial hemorrhage was diagnosed by computed tomography and ultrasound found to be frequent not only in babies who died. Hemorrhage was soon linked to cerebral palsy in surv...

  7. Effects of a Supported Speed Treadmill Training Exercise Program on Impairment and Function for Children with Cerebral Palsy

    Science.gov (United States)

    Johnston, Therese E.; Watson, Kyle E.; Ross, Sandy A.; Gates, Philip E.; Gaughan, John P.; Lauer, Richard T.; Tucker, Carole A.; Engsberg, Jack R.

    2011-01-01

    Aim: To compare the effects of a supported speed treadmill training exercise program (SSTTEP) with exercise on spasticity, strength, motor control, gait spatiotemporal parameters, gross motor skills, and physical function. Method: Twenty-six children (14 males, 12 females; mean age 9y 6mo, SD 2y 2mo) with spastic cerebral palsy (CP; diplegia, n =…

  8. Effects of a Supported Speed Treadmill Training Exercise Program on Impairment and Function for Children with Cerebral Palsy

    Science.gov (United States)

    Johnston, Therese E.; Watson, Kyle E.; Ross, Sandy A.; Gates, Philip E.; Gaughan, John P.; Lauer, Richard T.; Tucker, Carole A.; Engsberg, Jack R.

    2011-01-01

    Aim: To compare the effects of a supported speed treadmill training exercise program (SSTTEP) with exercise on spasticity, strength, motor control, gait spatiotemporal parameters, gross motor skills, and physical function. Method: Twenty-six children (14 males, 12 females; mean age 9y 6mo, SD 2y 2mo) with spastic cerebral palsy (CP; diplegia, n =…

  9. Fingertip force planning during grasp is disrupted by impaired sensorimotor integration in children with hemiplegic cerebral palsy

    NARCIS (Netherlands)

    Gordon, A.M.; Charles, J.; Steenbergen, B.

    2006-01-01

    In the present study we examine the ability of children with hemiplegic cerebral palsy (CP) to use anticipatory control of fingertip forces during grasping, and whether anticipatory control is facilitated by lifts with the contralateral hand. Eight children with CP (age 4-13) were asked to perform s

  10. [THE EFFECTIVENESS OF DIAGNOSIS AND TREATMENT OF CEREBROVASCULAR DISORDERS IN HYPERTENSIVE ENCEPHALOPATHY IN ELDERLY PATIENTS BY STUDYING THE CHARACTERISTICS OF CEREBRAL HEMODYNAMICS AND CEREBRAL PERFUSION STATUS].

    Science.gov (United States)

    Sviridova, N K; Yavorsky, V V

    2015-01-01

    Intrigue progression of hypertensive encephalopathy (HE) in older patients is that the development of cognitive impairment and high blood pressure underestimated, aslo exist without clinical manifestations. In recent decades convincing proved that the basis for the development of various diseases is cerebral dysfunction systems regulating brain blood flow, including--autoregulation system, which largely affects the blood supply to the brain. This explains the fact that patients with chronic brain ischemia cerebral hemodynamic status largely depends on the condition and stability of the regulatory mechanisms of systemic and cerebral hemodynamics, particularly of systemic blood pressure, regional cerebral blood supply, normalization which, in the early stages of development disorders, prevents of serious complications. In this paper the theoretical generalization and new solution of scientific and practical problems of hypertension influence on the formation of chronic cerebral ischemia in elderly patients on a background of hypertension--specified risk factors and especially the formation of a comprehensive study on the basis of clinical and neurological data, tool sand methods for neuroimaging research developed and improved methods of diagnosis. Found that in elderly patients with HE and HBP observed significant (P < 0.05) increase in the thickness of the intima-media complex was significantly higher (dextra--1.12 ± 0.03 and sinistra--1.11 ± 0.03), than middle-aged patients with hypertension at HE, which constitutes a violation of the elastic properties of the vascular wall. Established correlation data radionuclide study ultrasonic duplex scanning of vessels of the head and neck. A negative correlation of intima-media and severity of lesions according to hypoperfusion of computer tomography single photon emission (r = -0.49; P < 0.05); confirming the progression of HE in elderly patients needs improvement and treatment.

  11. Impaired renal function is related to deep and mixed, but not strictly lobar cerebral microbleeds in patients with ischaemic stroke and TIA.

    Science.gov (United States)

    Banerjee, Gargi; Wahab, Kolawole W; Gregoire, Simone M; Jichi, Fatima; Charidimou, Andreas; Jäger, Hans R; Rantell, Khadija; Werring, David J

    2016-04-01

    The vasculature of the brain and kidneys are similarly vulnerable to hypertension, so their microvascular damage may be correlated. We investigated the relationship of renal function to the anatomical distribution of cerebral microbleeds (CMBs), a marker of underlying cerebral small vessel disease (hypertensive arteriopathy or cerebral amyloid angiopathy), in a Western patient cohort. This was a retrospective study of referrals to a hospital stroke service. All patients with clinical data and a T2*-weighted gradient-recalled echo (T2*-GRE) MRI were included. MRI scans were rated for CMBs using the Microbleed Anatomical Rating Scale. Renal function was assessed by estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease formula. We included 202 patients, 39 with CMBs (19.3 %); 15 had "strictly lobar", 12 had "strictly deep" and 12 had "mixed" CMBs. Patients without CMBs had a higher eGFR than those with CMBs (mean difference 6.50 ml/min/1.73 m(2), 95 % CI -14.73 to 1.72 ml/min/1.73 m(2), p = 0.121). Multivariable analysis found that those with deep and mixed CMBs had a lower eGFR than those without CMBs (mean difference -10.70 ml/min/1.73 m(2), 95 % CI -20.35 to -1.06 ml/min/1.73 m(2), p = 0.030). There was no difference in eGFR found between those with strictly lobar CMBs and those without CMBs (mean difference -1.59 ml/min/1.73 m(2), 95 % CI -13.08 to 9.89 ml/min/1.73 m(2), p = 0.79). In a Western patient cohort, there appears to be an association between eGFR and the presence of deep and mixed CMBs, but not strictly lobar CMBs. This suggests a shared vulnerability of renal afferent and cerebral deep and superficial perforating arterioles to systemic hypertension. The arteriopathy underlying strictly lobar CMBs (i.e. cerebral amyloid angiopathy), appears to be less related to renal impairment.

  12. The Association between Cerebral White Matter Lesions and Plasma Omega-3 to Omega-6 Polyunsaturated Fatty Acids Ratio to Cognitive Impairment Development

    Directory of Open Access Journals (Sweden)

    Michihiro Suwa

    2015-01-01

    Full Text Available Objective. Cerebral white matter hyperintensity (WMH with magnetic resonance imaging (MRI has a potential for predicting cognitive impairment. Serum polyunsaturated fatty acid (PUFA levels are important for evaluating the extent of atherosclerosis. We investigated whether abnormal PUFA levels affected WMH grading and cognitive function in patients without significant cognitive impairment. Methods. Atherosclerotic risk factors, the internal carotid artery (ICA plaque, and serum ratios of eicosapentaenoic to arachidonic acids (EPA/AA and docosahexaenoic to arachidonic acids (DHA/AA were assessed in 286 patients. The relationship among these risk factors, WMH, and cognitive function was evaluated using WMH grading and the Mini-Mental State Examination (MMSE. Results. The development of WMH was associated with aging, hypertension, ICA plaques, and a low serum EPA/AA ratio (<0.38, obtained as the median value but was not related to dyslipidemia, diabetes, smoking, and a low serum DHA/AA ratio (<0.84, obtained as the median value. In addition, the MMSE score deteriorated slightly with the progression of WMH (29.7 ± 1.0 compared to 28.4 ± 2.1, P<0.0001. Conclusions. The progression of WMH was associated with a low serum EPA/AA ratio and accompanied minimal deterioration in cognitive function. Sufficient omega-3 PUFA intake may be effective in preventing the development of cognitive impairment.

  13. Bilingualism as a contributor to cognitive reserve?Evidence from cerebral glucose metabolism in mild cognitive impairment and Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Magdalena Eva Kowoll

    2016-04-01

    Full Text Available Objective: Bilingualism is discussed as one factor contributing to ‘cognitive reserve’ (CR as it enhances executive control functions. To elucidate the underlying cerebral correlates regional glucose uptake was compared between bilinguals and monolinguals with mild cognitive impairment (MCI and beginning Alzheimer´s disease (AD by using [18F]fluorodeoxyglucose (FDG positron emission tomography (PET. Methods: 30 patients (73.2 ± 7.4 diagnosed with MCI or probable AD received physical and neuropsychological examinations, blood tests and FDG-PET scans. 16 patients were classified as lifelong bilinguals following the criterion of Bialystok et al.; groups were matched for age, sex and MMSE scores. Analyses were conducted using SPM 8 using the whole brain as reference region for intensity normalization controlling for years of education.Results: Bilingual patient groups showed substantially greater impairment of glucose uptake in frontotemporal and parietal regions (including Brodmann areas 9, 47, 40 and 21 and in the left cerebellum relative to monolingual patients.Conclusions: Bilingualism is likely to contribute to CR given that bilingual patients showed more severe brain changes than monolinguals when adjusting for severity of cognitive impairment . The latter did not only comprise Brodmann areas relevant to speech and language but also structures typically involved in AD pathology such as the temporal and the parietal cortices.

  14. β-Amyloid (1–42 Levels in Cerebrospinal Fluid and Cerebral Atrophy in Mild Cognitive Impairment and Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Elmar Kaiser

    2011-11-01

    Full Text Available Background: Recent studies consistently reported Alzheimer’s disease (AD and, to a lower extent, mild cognitive impairment (MCI to be accompanied by reduced cerebrospinal fluid (CSF levels of β-amyloid. However, how these changes are related to brain morphological alterations is so far only partly understood. Methods: CSF levels of β-amyloid (1–42 were examined with respect to cerebral atrophy in 23 subjects with MCI, 16 patients with mild-to-moderateAlzheimer’s disease (AD and 15 age-matched controls by using magnetic resonance imaging and voxel-based morphometry (VBM. Results: When contrasted with the controls, β-amyloid (1–42 levels were significantly lower (p Conclusion: Our finding confirms the results of previous studies and suggests that both the decrease in β-amyloid (1–42 and the development of hippocampal atrophy coincide in the disease process.

  15. Regional cerebral blood flow estimated by early PiB uptake is reduced in mild cognitive impairment and associated with age in an amyloid-dependent manner.

    Science.gov (United States)

    Gietl, Anton F; Warnock, Geoffrey; Riese, Florian; Kälin, Andrea M; Saake, Antje; Gruber, Esmeralda; Leh, Sandra E; Unschuld, Paul G; Kuhn, Felix P; Burger, Cyrill; Mu, Linjing; Seifert, Burkhardt; Nitsch, Roger M; Schibli, Roger; Ametamey, Simon M; Buck, Alfred; Hock, Christoph

    2015-04-01

    Early uptake of [(11)C]-Pittsburgh Compound B (ePiB, 0-6 minutes) estimates cerebral blood flow. We studied ePiB in 13 PiB-negative and 10 PiB-positive subjects with mild cognitive impairment (MCI, n = 23) and 11 PiB-positive and 74 PiB-negative cognitively healthy elderly control subjects (HCS, n = 85) in 6 bilateral volumes of interest: posterior cingulate cortex (PCC), hippocampus (hipp), temporoparietal region, superior parietal gyrus, parahippocampal gyrus (parahipp), and inferior frontal gyrus (IFG) for the associations with cognitive status, age, amyloid deposition, and apolipoprotein E ε4-allele. We observed no difference in ePiB between PiB-positive and -negative subjects and carriers and noncarriers. EPiB decreased with age in PiB-positive subjects in bilateral superior parietal gyrus, bilateral temporoparietal region, right IFG, right PCC, and left parahippocampal gyrus but not in PiB-negative subjects. MCI had lower ePiB than HCS (left PCC, left IFG, and left and right hipp). Lowest ePiB values were found in MCI of 70 years and older, who also displayed high cortical PiB binding. This suggests that lowered regional cerebral blood flow indicated by ePiB is associated with age in the presence but not in the absence of amyloid pathology.

  16. Sympathetic influence on cerebral blood flow and metabolism during exercise in humans

    DEFF Research Database (Denmark)

    Seifert, Thomas; Secher, Niels H

    2011-01-01

    This review focuses on the possibility that autonomic activity influences cerebral blood flow (CBF) and metabolism during exercise in humans. Apart from cerebral autoregulation, the arterial carbon dioxide tension, and neuronal activation, it may be that the autonomic nervous system influences CBF......, but increases during cycling exercise. The increase in CMRO(2) is unaffected by beta-adrenergic blockade even though CBF is reduced suggesting that cerebral oxygenation becomes critical and a limited cerebral mitochondrial oxygen tension may induce fatigue. Also, sympathetic activity may drive cerebral non...

  17. Baclofen ameliorates spatial working memory impairments induced by chronic cerebral hypoperfusion via up-regulation of HCN2 expression in the PFC in rats.

    Science.gov (United States)

    Luo, Pan; Chen, Cheng; Lu, Yun; Fu, TianLi; Lu, Qing; Xu, Xulin; Li, Changjun; He, Zhi; Guo, Lianjun

    2016-07-15

    Chronic cerebral hypoperfusion (CCH) causes memory deficits and increases the risk of vascular dementia (VD) through several biologically plausible pathways. However, whether CCH causes prefrontal cortex (PFC)-dependent spatial working memory impairments and Baclofen, a GABAB receptor agonist, could ameliorate the impairments is still not clear especially the mechanisms underlying the process. In this study, rats were subjected to permanent bilateral occlusion of the common carotid arteries (two-vessel occlusion, 2VO) to induce CCH. Two weeks later, rats were treated with 25mg/kg Baclofen (intraperitioneal injection, i.p.) for 3 weeks. Spatial working memory was evaluated in a Morris water maze using a modified delayed matching-to-place (DMP) procedure. Western blotting and immunohistochemistry were used to quantify the protein levels and protein localization. Our results showed that 2VO caused striking spatial working memory impairments, accompanied with a decreased HCN2 expression in PFC, but the protein levels of protein gene product 9.5 (PGP9.5, a neuron specific protein), glial fibrillary acidic protein (GFAP), synaptophysin (SYP), brain-derived neurotrophic factor (BDNF), parvalbumin (PV) and HCN1 were not distinguishably changed as compared with sham-operated rats. Baclofen treatment significantly improved the spatial working memory impairments caused by 2VO, accompanied with a reversion of 2VO-induced down-regulation of HCN2. Furthermore, there was a co-localization of HCN2 subunits and parvalbumin-positive neurons in PFC. Therefore, HCN2 may target inhibitory interneurons that is implicated in working memory processes, which may be a possible mechanism of the up-regulation of HCN2 by Baclofen treatment that reliefs spatial working memory deficits in rats with CCH.

  18. Technical innovations for the diagnosis and the rehabilitation of motor and perceptive impairments of the child with Cerebral Palsy

    OpenAIRE

    Ferrari, Alberto

    2010-01-01

    The treatment of the Cerebral Palsy (CP) is considered as the “core problem” for the whole field of the pediatric rehabilitation. The reason why this pathology has such a primary role, can be ascribed to two main aspects. First of all CP is the form of disability most frequent in childhood (one new case per 500 birth alive, (1)), secondarily the functional recovery of the “spastic” child is, historically, the clinical field in which the majority of the therapeutic methods and techniques (phys...

  19. Frequency domain analysis of noise in autoregulated gene circuits

    Science.gov (United States)

    Simpson, Michael L.; Cox, Chris D.; Sayler, Gary S.

    2003-01-01

    We describe a frequency domain technique for the analysis of intrinsic noise within negatively autoregulated gene circuits. This approach is based on the transfer function around the feedback loop (loop transmission) and the equivalent noise bandwidth of the system. The loop transmission, T, is shown to be a determining factor of the dynamics and the noise behavior of autoregulated gene circuits, and this T-based technique provides a simple and flexible method for the analysis of noise arising from any source within the gene circuit. We show that negative feedback not only reduces the variance of the noise in the protein concentration, but also shifts this noise to higher frequencies where it may have a negligible effect on the noise behavior of following gene circuits within a cascade. This predicted effect is demonstrated through the exact stochastic simulation of a two-gene cascade. The analysis elucidates important aspects of gene circuit structure that control functionality, and may provide some insights into selective pressures leading to this structure. The resulting analytical relationships have a simple form, making them especially useful as synthetic gene circuit design equations. With the exception of the linearization of Hill kinetics, this technique is general and may be applied to the analysis or design of networks of higher complexity. This utility is demonstrated through the exact stochastic simulation of an autoregulated two-gene cascade operating near instability. PMID:12671069

  20. Human apolipoprotein E ɛ4 expression impairs cerebral vascularization and blood–brain barrier function in mice

    Science.gov (United States)

    Alata, Wael; Ye, Yue; St-Amour, Isabelle; Vandal, Milène; Calon, Frédéric

    2015-01-01

    Human apolipoprotein E (APOE) exists in three isoforms ɛ2, ɛ3, and ɛ4, of which APOE4 is the main genetic risk factor of Alzheimer's disease (AD). As cerebrovascular defects are associated with AD, we tested whether APOE genotype has an impact on the integrity and function of the blood–brain barrier (BBB) in human APOE-targeted replacement mice. Using the quantitative in situ brain perfusion technique, we first found lower (13.0% and 17.0%) brain transport coefficient (Clup) of [3H]-diazepam in APOE4 mice at 4 and 12 months, compared with APOE2 and APOE3 mice, reflecting a decrease in cerebral vascularization. Accordingly, results from immunohistofluorescence experiments revealed a structurally reduced cerebral vascularization (26% and 38%) and thinner basement membranes (30% and 35%) in 12-month-old APOE4 mice compared with APOE2 and APOE3 mice, suggesting vascular atrophy. In addition, APOE4 mice displayed a 29% reduction in [3H]-d-glucose transport through the BBB compared with APOE2 mice without significant changes in the expression of its transporter GLUT1 in brain capillaries. However, an increase of 41.3% of receptor for advanced glycation end products (RAGE) was found in brain capillaries of 12-month-old APOE4 mice. In conclusion, profound divergences were observed between APOE genotypes at the cerebrovascular interface, suggesting that APOE4-induced BBB anomalies may contribute to AD development. PMID:25335802

  1. Human apolipoprotein E ɛ4 expression impairs cerebral vascularization and blood-brain barrier function in mice.

    Science.gov (United States)

    Alata, Wael; Ye, Yue; St-Amour, Isabelle; Vandal, Milène; Calon, Frédéric

    2015-01-01

    Human apolipoprotein E (APOE) exists in three isoforms ɛ2, ɛ3, and ɛ4, of which APOE4 is the main genetic risk factor of Alzheimer's disease (AD). As cerebrovascular defects are associated with AD, we tested whether APOE genotype has an impact on the integrity and function of the blood-brain barrier (BBB) in human APOE-targeted replacement mice. Using the quantitative in situ brain perfusion technique, we first found lower (13.0% and 17.0%) brain transport coefficient (Clup) of [(3)H]-diazepam in APOE4 mice at 4 and 12 months, compared with APOE2 and APOE3 mice, reflecting a decrease in cerebral vascularization. Accordingly, results from immunohistofluorescence experiments revealed a structurally reduced cerebral vascularization (26% and 38%) and thinner basement membranes (30% and 35%) in 12-month-old APOE4 mice compared with APOE2 and APOE3 mice, suggesting vascular atrophy. In addition, APOE4 mice displayed a 29% reduction in [(3)H]-d-glucose transport through the BBB compared with APOE2 mice without significant changes in the expression of its transporter GLUT1 in brain capillaries. However, an increase of 41.3% of receptor for advanced glycation end products (RAGE) was found in brain capillaries of 12-month-old APOE4 mice. In conclusion, profound divergences were observed between APOE genotypes at the cerebrovascular interface, suggesting that APOE4-induced BBB anomalies may contribute to AD development.

  2. Lithium chloride administration prevents spatial learning and memory impairment in repeated cerebral ischemia-reperfusion mice by depressing apoptosis and increasing BDNF expression in hippocampus.

    Science.gov (United States)

    Fan, Mingyue; Jin, Wei; Zhao, Haifeng; Xiao, Yining; Jia, Yanqiu; Yin, Yu; Jiang, Xin; Xu, Jing; Meng, Nan; Lv, Peiyuan

    2015-09-15

    Lithium has been reported to have neuroprotective effects, but the preventive and treated role on cognition impairment and the underlying mechanisms have not been determined. In the present study, C57Bl/6 mice were subjected to repeated bilateral common carotid artery occlusion to induce the learning and memory deficits. 2 mmol/kg or 5 mmol/kg of lithium chloride (LiCl) was injected intraperitoneally per day before (for 7 days) or post (for 28 days) the operation. This repeated cerebral ischemia-reperfusion (IR) induced dynamic overexpression of ratio of Bcl-2/Bax and BDNF in hippocampus of mice. LiCl pretreatment and treatment significantly decreased the escape latency and increased the percentage of time that the mice spent in the target quadrant in Morris water maze. 2 mmol/kg LiCl evidently reversed the morphologic changes, up-regulated the survival neuron count and increased the BDNF gene and protein expression. 5 mmol/kg pre-LiCl significantly increased IR-stimulated reduce of Bcl-2/Bax and p-CREB/CREB. These results described suggest that pre-Li and Li treatment may induce a pronounced prevention on cognitive impairment. These effects may relay on the inhibition of apoptosis and increasing BDNF and p-CREB expression.

  3. Cerebral perfusion (HMPAO-SPECT) in patients with depression with cognitive impairment versus those with mild cognitive impairment and dementia of Alzheimer's type: a semiquantitative and automated evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Staffen, W.; Bergmann, J.; Schoenauer, U.; Kronbichler, M.; Golaszewski, S.; Ladurner, G. [Paracelsus Medical University, Christian-Doppler-Clinic, Department of Neurology, and Center of Cognitive Research Salzburg, Salzburg (Austria); Zauner, H. [Rehabilitation Center of the Pensionsversicherungsanstalt, Grossgmain (Austria)

    2009-05-15

    Comparative evaluation of regional brain perfusion measured by HMPAO-SPECT of patients with mild cognitive impairment (MCI), dementia of Alzheimer's type (DAT) and depression with cognitive impairment (DCI). A total of 736 patients were investigated because of suspected cognitive dysfunction. After exclusion of patients with other forms of dementia than DAT or relevant accompanying disorders, SPECT data from 149 MCI, 131 DAT and 127 DCI patients, and 123 controls without any cognitive impairment, were analysed. Relative cerebral blood flow of 34 anatomical regions was assessed with automated analysis software (BRASS). Calculation of global forebrain perfusion discriminated demented from nondemented patients. Compared to controls DCI patients showed hypoperfusion of the thalamus, lentiform nucleus and medial temporal cortex. MCI patients differed significantly from controls concerning perfusion in both hemispheric temporal and parietal areas, and in the (right hemispheric) posterior part of the cingulate gyrus. MCI and DCI patients differed in the parietal, temporal superior and right hemispheric cingulate gyrus posterior cortices. Global forebrain and regional perfusion was more extensively reduced in DAT patients and discriminated them from controls, and MCI and DCI patients. Frontal perfusion disturbance was only present in DAT patients. Automated analysis of HMPAO-SPECT data from MCI patients showed significant perfusion deficits in regions also involved in DAT patients, but ROC analysis demonstrated only moderate sensitivity and specificity for differentiating DAT patients from controls and DCI patients. Frontal hypoperfusion seems to correspond with conversion from MCI to DAT. Finally, the results in DCI patients again raise the question of depression as an early symptom of neurodegeneration. (orig.)

  4. Impaired gait function in adults with cerebral palsy is associated with reduced rapid force generation and increased passive stiffness

    DEFF Research Database (Denmark)

    Geertsen, Svend Sparre; Kirk, Henrik; Lorentzen, Jakob

    2015-01-01

    analysis of the ankle joint during treadmill walking was obtained by 3-D motion analysis. RESULTS: Passive stiffness was significantly increased in adults with CP compared to controls. Passive stiffness and RFDdf were correlated to reduced toe lift. RFDpf provided the best correlation to push-off velocity...... (mean age 34.3, range 18-57years) and fifteen healthy age-matched controls were biomechanically measured for passive and reflex-mediated stiffness of the ankle plantarflexors at rest, maximal voluntary plantarflexion and dorsiflexion effort (MVCpf,df) and rate of force development (RFDpf,df). Kinematic......, range of movement in the ankle joint and gait speed. Reflex-mediated stiffness was not correlated to any parameters of impaired gait. CONCLUSIONS: Impaired gait function in adults with CP is associated with reduced RFD and increased passive stiffness of ankle muscles. SIGNIFICANCE: These findings...

  5. The Longitudinal Evolution of Cerebral Blood Flow Regulation after Acute Ischaemic Stroke

    Directory of Open Access Journals (Sweden)

    Angela S.M. Salinet

    2014-08-01

    Full Text Available Background: Acute stroke is known to impair cerebral blood flow (CBF regulation, but the longitudinal changes of these effects have been poorly reported. The main CBF regulatory mechanisms [cerebral autoregulation (CA and neurovascular coupling (NVC] were assessed over 3 months after acute ischaemic stroke. Methods: Recordings of CBF velocity (CBFv, blood pressure (BP, and end-tidal CO2 were performed during 5 min baseline and 1 min passive movement of the elbow. Stroke patients were assessed Results: Fifteen acute stroke subjects underwent all 4 sessions and were compared to 22 control subjects. Baseline recordings revealed a significantly lower CBFv in the affected hemisphere within 72 h after stroke compared to controls (p = 0.02 and a reduction in CA index most marked at 2 weeks (p = 0.009. CBFv rise in response to passive arm movement was decreased bilaterally after stroke, particularly in the affected hemisphere (p Conclusion: The major novel finding of this study was that both CA and NVC regulatory mechanisms deteriorated initially following stroke onset, but returned to control levels during the recovery period. These findings are relevant to guide the timing of interventions to manipulate BP and potentially for the impact of intensive rehabilitation strategies that may precipitate acute physiological perturbations but require further exploration in a larger population that better reflects the heterogeneity of stroke. Further, they will also enable the potential influence of stroke subtype to be investigated.

  6. Mild cognitive impairment, poor episodic memory, and late-life depression are associated with cerebral cortical thinning and increased white matter hyperintensities

    Directory of Open Access Journals (Sweden)

    Motonobu eFujishima

    2014-11-01

    Full Text Available In various independent studies to date, cerebral cortical thickness and white matter hyperintensity (WMH volume have been associated with episodic memory, depression, and mild cognitive impairment (MCI. The aim of this study was to uncover variations in cortical thickness and WMH volume in association with episodic memory, depressive state, and the presence of MCI simultaneously in a single study population. The participants were 186 individuals with MCI (clinical dementia rating [CDR] of 0.5 and 136 healthy elderly controls (HCs; CDR of 0 drawn from two community-based cohort studies in northern Japan. We computed cerebral cortical thickness and WMH volume by using MR scans and statistically analyzed differences in these indices between HCs and MCI participants. We also assessed the associations of these indices with memory performance and depressive state in participants with MCI. Compared with HCs, MCI participants exhibited thinner cortices in the temporal and inferior parietal lobes and greater WMH volumes in the corona radiata and semioval center. In MCI participants, poor episodic memory was associated with thinner cortices in the left entorhinal region and increased WMH volume in the posterior periventricular regions. Compared with non-depressed MCI participants, depressed MCI participants showed reduced cortical thickness in the anterior medial temporal lobe and ambient gyrus adjacent to the amygdala bilaterally, as well as greater WMH volume as a percentage of the total intracranial volume (WMHr. A higher WMHr was associated with cortical thinning in the frontal, temporal, and parietal regions in MCI participants. These results demonstrate that episodic memory and depression are associated with both cortical thickness and WMH volume in MCI participants. Additional longitudinal studies are needed to clarify the dynamic associations and interactions among these indices.

  7. Role of the renin-angiotensin system in regulation and autoregulation of renal blood flow

    DEFF Research Database (Denmark)

    Sørensen, Charlotte Mehlin; Leyssac, Paul Peter; Skøtt, Ole;

    2000-01-01

    The role for ANG II in renal blood flow (RBF) autoregulation is unsettled. The present study was designed to test the effect of clamping plasma ANG II concentrations ([ANG II]) by simultaneous infusion of the angiotensin-converting enzyme inhibitor captopril and ANG II on RBF autoregulation in ha...

  8. Pattern of cerebral hyperperfusion in Alzheimer's disease and amnestic mild cognitive impairment using voxel-based analysis of 3D arterial spin-labeling imaging: initial experience

    Directory of Open Access Journals (Sweden)

    Ding B

    2014-03-01

    Full Text Available Bei Ding,1 Hua-wei Ling,1 Yong Zhang,2 Juan Huang,1 Huan Zhang,1 Tao Wang,3 Fu Hua Yan11Department of Radiology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, 2Applied Science Laboratory, GE Healthcare, 3Department of Gerontology, Shanghai Mental Health Center, Shanghai, People's Republic of ChinaPurpose: A three-dimensional (3D continuous pulse arterial spin labeling (ASL technique was used to investigate cerebral blood flow (CBF changes in patients with Alzheimer's disease (AD, amnestic mild cognitive impairment (aMCI, and age- and sex-matched healthy controls.Materials and methods: Three groups were recruited for comparison, 24 AD patients, 17 MCI patients, and 21 age- and sex-matched control subjects. Three-dimensional ASL scans covering the entire brain were acquired with a 3.0 T magnetic resonance scanner. Spatial processing was performed with statistical parametric mapping 8. A second-level one-way analysis of variance analysis (threshold at P<0.05 was performed on the preprocessed ASL data. An average whole-brain CBF for each subject was also included as group-level covariates for the perfusion data, to control for individual CBF variations.Results: Significantly increased CBF was detected in bilateral frontal lobes and right temporal subgyral regions in aMCI compared with controls. When comparing AD with aMCI, the major hyperperfusion regions were the right limbic lobe and basal ganglia regions, including the putamen, caudate, lentiform nucleus, and thalamus, and hypoperfusion was found in the left medial frontal lobe, parietal cortex, the right middle temporo-occipital lobe, and particularly, the left anterior cingulate gyrus. We also found decreased CBF in the bilateral temporo-parieto-occipital cortices and left limbic lobe in AD patients, relative to the control group. aMCI subjects showed decreased blood flow in the left occipital lobe, bilateral inferior temporal cortex, and right middle temporal cortex

  9. Autoregulation monitoring and outcome prediction in neurocritical care patients: Does one index fit all?

    Science.gov (United States)

    Schmidt, Bernhard; Reinhard, Matthias; Lezaic, Vesna; McLeod, Damian D; Weinhold, Marco; Mattes, Heinz; Klingelhöfer, Jürgen

    2016-06-01

    Indexes PRx and Mx have been formerly introduced to assess cerebral autoregulation and have been shown to be associated with 3-month clinical outcome. In a mixed cohort of neurocritical care patients, we retrospectively investigated the impact of selected clinical characteristics on this association. Forty-one patients (18-77 years) with severe traumatic (TBI, N = 20) and non-traumatic (N = 21) brain injuries were studied. Cerebral blood flow velocity, arterial blood pressure and intracranial pressure were repeatedly recorded during 1-h periods. Calculated PRx and Mx were correlated with 3-month clinical outcome score of modified Rankin Scale (mRS) in different subgroups with specific clinical characteristics. Both PRx and Mx correlated significantly with outcome (PRx: r = 0.38, p PRx: r = 0.73, p PRx, correlated significantly with mRS in patients with heart failure (N = 17; r = 0.69, p PRx, not Mx, correlated significantly with mRS in TBI patients (r = 0.63, p PRx failed in hypocapnic patients (N = 26). Both PRx and Mx were significantly associated with 3-month clinical outcome, even in patients with hemicraniectomy. PRx was more appropriate for TBI patients, while Mx was better suited for non-traumatic patients and patients with heart failure. Prognostic values of indexes were affected by diabetes (both Mx and PRx) and hypocapnia (PRx only).

  10. Cerebral Visual Impairment and Dysgenesis of Corpus Callosum in Multidisabled Children Aged 1 to 9 Years Old

    Directory of Open Access Journals (Sweden)

    Roxana CZIKER

    2009-12-01

    Full Text Available Aims: To emphasize the functional vision characteristics in visually impaired multiple disabled children (MDVI aged 2 to 9 years old related to brain damages on magnetic resonance imaging in different cortical and subcortical areas and in the corpus callosum region. Material and Method: 12 MDVI children with severe and mild neurological disorders were medically and neuropsychological assessed. The clinical - psychological, neurological and ophthalmological – and paraclinical methods – visual evoked potential (VEP and magnetic resonance imaging (MRI were carried out in order to outline the complete profile of each child. The assessment was completed by morphometric measurement of corpus callosum and brain. Results: 10 of infants with severe neurological disorders showed ocular disorders such as ocular motility and visual function abnormalities. Severe cognitive and psychomotor retardation were associated in visual disorders in MDVI children. Significant correlation between neurological disorders, neuropsychological [τ(12 = 0.783, p = 0.001] evaluation and visual acuity [τ(12 = 0.783, p = 0.001] were found in multiple disabled children. The significant difference of diameter [t(22 = -4.858, p = 0.000] and surface of corpus callosum [t(22 = -6.254, p = 0.000] in multiple disabled children compared with control group was found. Conclusion: The structured assessment of visually impaired children due to neurological disorders, as early as possible, is the remarkably key which reveals the functionality of child and outlines the appropriate developmental and educational rehabilitation.

  11. Transient influence of end-tidal carbon dioxide tension on the postural restraint in cerebral perfusion

    DEFF Research Database (Denmark)

    Immink, R.V.; Truijen, J.; Secher, Niels H.

    2009-01-01

    In the upright position, cerebral blood flow is reduced, maybe because arterial carbon dioxide partial pressure (Pa(CO(2))) decreases. We evaluated the time-dependent influence of a reduction in Pa(CO(2)), as indicated by the end-tidal Pco(2) tension (Pet(CO(2))), on cerebral perfusion during head......-up tilt. Mean arterial pressure, cardiac output, middle cerebral artery mean flow velocity (MCA V(mean)), and dynamic cerebral autoregulation at supine rest and 70 degrees head-up tilt were determined during free breathing and with Pet(CO(2)) clamped to the supine level. The postural changes in central...

  12. Moderate hyperventilation during intravenous anesthesia increases net cerebral lactate efflux

    NARCIS (Netherlands)

    F. Grüne (Frank); S. Kazmaier (Stephan); B. Sonntag (Barbara); R.J. Stolker (Robert); A. Weyland (Andreas)

    2014-01-01

    textabstractBACKGROUND:: Hyperventilation is known to decrease cerebral blood flow (CBF) and to impair cerebral metabolism, but the threshold in patients undergoing intravenous anesthesia is unknown. The authors hypothesized that reduced CBF associated with moderate hyperventilation might impair cer

  13. 脑梗死患者轻度肾功能损伤的相关研究%Research on cerebral infarction patients with mild renal impairment

    Institute of Scientific and Technical Information of China (English)

    李娟; 张敏; 夏章勇

    2014-01-01

    Objective To investigate the risk factors of mild renal impairment in cerebral infarction patients.Methods One hundred and fifty patients with cerebral infarction were enrolled from June 2012 to June 2013,and all patients received cranial magnetic resonance imaging at the first week.The clinical data of patients were recorded in detail,24 h microalbuminuria (mALB) was detected,renal function was assessed.According to mALB,the patients were divided into normal renal function group (105 cases) and mild renal dysfunction group (45 cases).Clinical risk factors between 2 groups were compared,and multivariate regression analysis was done.Results Age in mild renal dysfunction group was greater than that in normal renal function group [(67.04 ±9.37) years vs.(63.01 ± 11.18) years],the incidence of hypertension and multiple lacunar infarction were higher than those in normal renal function group[57.8% (26/45) vs.33.3% (35/105),57.8% (26/45) vs.22.9% (24/105)],leukoaraiosis grade was higher than that in normal renal function group,there were significant differences (P < 0.05 or < 0.01).Logistic regression analysis found that hypertension (OR =1.04 1,P =0.045) and leukoaraiosis (OR =2.048,P =0.000) were independent risk factors for cerebral infarction patients with mild renal impairment.Conclusions The incidence of mild renal impairment is higher in cerebral infarction patients,and is closely related to hypertension and leukoariosis.Early detection of 24 h mALB in cerebral infarction patients has important clinical significance.%目的 探讨脑梗死患者轻度肾功能损伤的相关危险因素.方法 选择2012年6月至2013年6月收治的脑梗死患者150例,均行磁共振检查,详细记录患者的临床资料,并检测24 h尿微量白蛋白(mALB),评估肾功能.根据mALB分为肾功能正常组(105例)及轻度肾功能损伤组(45例).比较两组临床危险因素,并进行多因素回归分析.结果 轻度肾功能损伤组患者

  14. Dynamics of renal blood flow autoregulation in rats

    DEFF Research Database (Denmark)

    Holstein-Rathlou, N H; Wagner, A J; Marsh, D J

    1991-01-01

    Two separate components could be resolved in tests of the dynamic autoregulation of renal blood flow. The slow component corresponds to the frequency at which spontaneous proximal tubular pressure oscillations are found, and are most likely due to the operation of the TGF. The high frequency...... component most likely represents an intrinsic vascular, myogenic, mechanism. The gain maximum of the admittance in the frequency range corresponding to the autonomous tubular oscillations indicates that the dynamic characteristics responsible for the occurrence of the spontaneous tubular oscillations must...

  15. The effect of negative autoregulation on eukaryotic gene expression

    Science.gov (United States)

    Nevozhay, Dmitry; Adams, Rhys; Murphy, Kevin; Josic, Kresimir; Balázsi, G. Ábor

    2009-03-01

    Negative autoregulation is a frequent motif in gene regulatory networks, which has been studied extensively in prokaryotes. Nevertheless, some effects of negative feedback on gene expression in eukaryotic transcriptional networks remain unknown. We studied how the strength of negative feedback regulation affects the characteristics of gene expression in yeast cells carrying synthetic transcriptional cascades. We observed a drastic reduction of gene expression noise and a change in the shape of the dose-response curve. We explained these experimentally observed effects by stochastic simulations and a simple set of algebraic equations.

  16. Clinical research on cognitive function impairment after acute cerebral infarction%急性脑梗死后认知功能障碍的临床研究

    Institute of Scientific and Technical Information of China (English)

    严春梅; 李燕

    2011-01-01

    Objective To analyze the(ACI) relationship between infarction sites and cognitive impairment after acute cerebral infarction.Methods A total of 134 patients with first ACI and 50 healthy control subjects matched with age, sex and education level were selected.All subjects were assessed with mini-mental state examination (MMSE), clinical memory scale ( CMS), verbal fluency test ( VFT), clock drawing task ( CDT), Barthel index (B1) assessment,Haehinski ischemic scale (HIS), Hamilton depression scale (HAMD).All patients and healthy control subjects were examined with event-related potentials (ERP) P300 test.The relationship between Results of above-mentioned neuropsychological assessment and P300 findings were compared and analyzed in accordance with the neuroimaging type of cerebral infarction.Results 1.There was statistical significance in differences of scores of MMSE, CMS, VFT, CDT between middle infarction and lacunar infarction ( P 0.05 ).2.In middle infarction and small infarction subgroups: the scores of MMSE, CMS in frontal lobe infarction and temporal lobe infarction were lower than those in basal ganglia infarction, parietal lobe infarction and occipital lobe infarction; the scores of MMSE, CMS in basal ganglia infarction were lower than those in parietal lobe infarction and occipital lobe infarction, all had statistically significant differences( P 0.05 ).Conclusion The location of cerebral infarction is closely related with cognitive function impairment after ACI.%目的 探讨并分析梗死灶部位与急性脑梗死(ACI)后认知功能障碍的关系.方法 选取134例ACI患者(ACI组)和100例健康人(对照组)进行简易精神状态检查表(MMSE)、临床记忆量表(CMS)、词语流畅性测验(VFT)、画钟测验(CDT)等评定,并行F300检查,将神经心理学量表评定结果及P300检查结果按照脑梗死的影像学分型进行对比研究.结果 1.中梗死与腔隙性梗死MMSE、CMS、VFT、CDT评分差异均有统计学意义(P0

  17. RBC-coupled tPA prevents cerebrovasodilatory impairment and tissue injury in pediatric cerebral hypoxia/ischemia through inhibition of ERK MAPK unregulation

    Energy Technology Data Exchange (ETDEWEB)

    Ganguly, Kumkum [Los Alamos National Laboratory; Armstead, William M [U PENNSYLVANIA; Kiessling, J W [U PENNSYLVANIA; Chen, Xiao - Han [U PENNSYLVANIA; Smith, Douglas H [U PENNSYLVANA; Higazi, Abd Ar [U PENNSYLVANIA; Cines, Douglas B [U PENNSYLVANIA; Bdeir, Khalil [U PENNSYLVANIA; Zaitsev, Sergei [U PENNSYLVANIA; Muzykantov, Vladimir R [U PENNSYLVANIA

    2008-01-01

    Babies experience hypoxia (H) and ischemia (I) from stroke. The only approved treatment for stroke is fibrinolytic therapy with tissue-type plasminogen activator (tPA). However, tPA potentiates H/I-induced impairment of responses to cerebrovasodilators such as hypercapnia and hypotension, and blockade of tPA-mediated vasoactivity prevents this deleterious effect. Coupling tPA to RBCs reduces its CNS toxicity through spatially confining the drug to the vasculature. Mitogen activated protein kinase (MAPK), a family of at least 3 kinases, is upregulated after H/I. In this study we determined if RBC-tPA given before or after cerebral H/I would preserve responses to cerebrovasodilators and prevent neuronal injury mediated through the ERK MAPK pathway. Animals given RBC-tPA maintained responses to cerebrovasodilators at levels equivalent to pre-H/I values. CSF and brain parenchymal ERK MAPK was elevated by H/I and this upregulation was potentiated by tPA, but blunted by RBC-tPA. U 0126, an ERK MAPK antagonist, also maintained cerebrovasodilation post H/I. Neuronal degeneration in CA1 hippocampus and parietal cortex after H/I was exacerbated by tPA, but ameliorated by RBC-tPA and U 0126. These data suggest that coupling tPA to RBCs may offer a novel approach towards increasing the benefit/risk ratio of thrombolytic therapy for CNS disorders associated with H/I.

  18. Perfusion Pressure Cerebral Infarct (PPCI) trial

    DEFF Research Database (Denmark)

    Vedel, Anne G.; Holmgaard, Frederik; Rasmussen, Lars Simon

    2016-01-01

    to be caused by emboli, but inadequate blood flow caused by other mechanisms may increase ischaemia in the penumbra or cause watershed infarcts. During cardiopulmonary bypass, blood pressure can be below the lower limit of cerebral autoregulation. Although much debated, the constant blood flow provided...... by the cardiopulmonary bypass system is still considered by many as appropriate to avoid cerebral ischaemia despite the low blood pressure. Methods/design: The Perfusion Pressure Cerebral Infarct trial is a single-centre superiority trial with a blinded outcome assessment. The trial is randomising 210 patients...... with coronary vessel and/or valve disease and who are undergoing cardiac surgery with the use of cardiopulmonary bypass. Patients are stratified by age and surgical procedure and are randomised 1:1 to either an increased mean arterial pressure (70–80 mmHg) or ‘usual practice’ (40–50 mmHg) during cardiopulmonary...

  19. Autoregulation of superficial nephron function in the alloperfused dog kidney.

    Science.gov (United States)

    Heller, J; Horácek, V

    1979-10-01

    Isolated dog kidneys were each pump-perfused by another dog during 4 experimental periods at perfusion pressures (PP) of 21, 17, 13, and 8 kPa, resp. (i.e. 160, 130, 94, and 60 mm Hg). At the 3 highest PP values, the total kidney renal blood flow (RBF) and glomerular filtration rate (GFR) were perfectly autoregulated while at the lowest value both values were significantly lowered. No significant difference was observed between the single nephron GFR (SNGFR) of periods 1 and 2; in period 3 (PP = 13 kPa) a lower value was observed (P less than 0.05). Free flow pressure in proximal convolution (FFP), stop-flow pressure (SFP), and peritubular capillary pressure (PCP) were not different in period 2 than in period 1, but were significantly lower in period 3 (P = 0.02--0.05). Effective filtration pressure (EFP) was the highest in period 1, decreasing significantly with decreasing PP. Filtration pressure equilibrium was observed in period 4 at PP 8 kPa. Total blood flow resistance (RT) fell with decreasing PP, the drop being due to a steep decline in afferent resistance (RA). Efferent resistance (RE) increased as PP decreased. Ultrafiltration coefficient (Kf) rose with declining PP both within and outside the autoregulatory range. The results indicate that the lower limit of autoregulation is higher in superficial nephrons than in the whole kidney.

  20. Negative autoregulation matches production and demand in synthetic transcriptional networks.

    Science.gov (United States)

    Franco, Elisa; Giordano, Giulia; Forsberg, Per-Ola; Murray, Richard M

    2014-08-15

    We propose a negative feedback architecture that regulates activity of artificial genes, or "genelets", to meet their output downstream demand, achieving robustness with respect to uncertain open-loop output production rates. In particular, we consider the case where the outputs of two genelets interact to form a single assembled product. We show with analysis and experiments that negative autoregulation matches the production and demand of the outputs: the magnitude of the regulatory signal is proportional to the "error" between the circuit output concentration and its actual demand. This two-device system is experimentally implemented using in vitro transcriptional networks, where reactions are systematically designed by optimizing nucleic acid sequences with publicly available software packages. We build a predictive ordinary differential equation (ODE) model that captures the dynamics of the system and can be used to numerically assess the scalability of this architecture to larger sets of interconnected genes. Finally, with numerical simulations we contrast our negative autoregulation scheme with a cross-activation architecture, which is less scalable and results in slower response times.

  1. Regional cerebral blood flow assessed with {sup 99m}Tc-ECD SPET as a marker of progression of mild cognitive impairment to Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Encinas, Marta; Juan, Ramon de; Cabranes, Jose Antonio [Department of Nuclear Medicine, Hospital Clinico San Carlos, Martin Lagos s/n, 28040, Madrid (Spain); Marcos, Alberto [Department of Neurology, Hospital Clinico San Carlos, Madrid (Spain); Gil, Pedro [Department of Geriatrics, Hospital Clinico San Carlos, Madrid (Spain); Barabash, Ana; Fernandez, Cristina; Ugarte, Carmen de [Research Unit, Hospital Clinico San Carlos, Madrid (Spain)

    2003-11-01

    Patients diagnosed with mild cognitive impairment (MCI) have a higher risk of developing Alzheimer's disease (AD). However, not all such patients develop this kind of dementia. The purpose of this prospective study was to assess whether regional cerebral blood flow (rCBF) patterns measured with technetium-99m ethyl cysteinate dimer single-photon emission tomography ({sup 99m}Tc-ECD SPET) in patients suffering from MCI are useful in predicting progression to AD. The study group comprised 42 patients who fulfilled MCI criteria according to the International Psychogeriatric Association and the Alzheimer's Disease Cooperative Study. rCBF was calculated in 16 regions of interest (ROIs). All patients were clinically assessed for 1-3 years. Twenty-one developed AD (group I) while the initial diagnosis of MCI was retained in the other 21 (group II). ROC curves were designed, and sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios were determined for each ROI. Compared with group II (MCI), group I (AD) showed a significant reduction of relative blood flow (RBF), ranging from 7% to 10%, in the following areas: right and left prefrontal, right and left frontal, right and left parietal, right and left temporal, right and left frontoparietotemporal and left posterior lateral temporal. Left prefrontal, left frontal and left parietal areas showed sensitivities and specificities higher than 75% and areas below the ROC curve close to 80%. This study shows that RBF patterns in the right and left prefrontal, right and left frontal and left parietal areas are sensitive early markers of progression towards AD. Reduction of rCBF in the medial temporal and anterior lateral temporal cortex has no value as a predictor since it also occurs in patients with MCI who remain stable. (orig.)

  2. Cerebral blood flow of patients with age-associated memory impairment and the early stage of Alzheimer`s disease. A study by SPECT using the ARG method

    Energy Technology Data Exchange (ETDEWEB)

    Ishiwata, Akiko; Kitamura, Shin; Nagazumi, Atushi; Terashi, Akiro [Nippon Medical School, Tokyo (Japan)

    1998-04-01

    In order to further understand the pathology of Alzheimer`s disease (AD), we have utilized image analysis in diagnosing the early stages of AD in patients with cognitive disorders. CT and MRI, however, have not been feasible since only atrophy is seen and it is difficult to differentiate the changes in AD from age associated changes. In this study we tried to determine whether regional cerebral blood flow (rCBF) measurements using single photon emission CT (SPECT) are feasible for the early diagnosis of AD. Regional CBF (rCBF) was measured using SPECT in three subject groups: Age-associated memory impairment (AAMI, n=9), mild AD (n=16), and normal aged patients (mean age=68.3; n=20). The subjects were then observed for three years. The region of interest (ROI) for the medial temporal lobe was set at OM-30deg to cover the maximum area of the hippocampus. The absolute values of rCBF in the frontal, temporal, and parietal lobes and the cerebellum were significantly lower in the mild AD subjects than in the normal aged subjects. A significant decrease in rCBF was also seen in the medial temporal lobe in both the AD and the AAMI subjects compared to the normal controls. During the three years of follow up, no cases of dementia were seen in the AAMI subjects. However, there were two patients who appeared to have difficulty in adapting to daily life due to amnesia, one with a decrease in rCBF of the medial temporal lobe on the second SPECT, and the other showing a low rCBF the first time. This study suggests that AAMI subjects may comprise both AD and normal subjects. Therefore a more prospective study is needed. (author)

  3. Trends in the prevalence of autism spectrum disorder, cerebral palsy, hearing loss, intellectual disability, and vision impairment, metropolitan atlanta, 1991-2010.

    Directory of Open Access Journals (Sweden)

    Kim Van Naarden Braun

    Full Text Available This study examined the prevalence and characteristics of autism spectrum disorder (ASD, cerebral palsy (CP, hearing loss (HL, intellectual disability (ID, and vision impairment (VI over a 15-20 year time period, with specific focus on concurrent changes in ASD and ID prevalence. We used data from a population-based developmental disabilities surveillance program for 8-year-olds in metropolitan Atlanta. From 1991-2010, prevalence estimates of ID and HL were stable with slight increases in VI prevalence. CP prevalence was constant from 1993-2010. The average annual increase in ASD prevalence was 9.3% per year from 1996-2010, with a 269% increase from 4.2 per 1,000 in 1996 to 15.5 per 1,000 in 2010. From 2000-2010, the prevalence of ID without ASD was stable; during the same time, the prevalence of ASD with and without co-occurring ID increased by an average of 6.6% and 9.6% per year, respectively. ASD prevalence increases were found among both males and females, and among nearly all racial/ethnic subgroups and levels of intellectual ability. Average annual prevalence estimates from 1991-2010 underscore the significant community resources needed to provide early intervention and ongoing supports for children with ID (13.0 per 1,000, CP, (3.5 per 1,000, HL (1.4 per 1,000 and VI (1.3 in 1,000, with a growing urgency for children with ASD.

  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. 脑小血管病与血管性认知功能障碍的关系%Relationship between Cerebral Small Vessel Disease and Vascular Cognitive Impairment

    Institute of Scientific and Technical Information of China (English)

    何敏; 朱晓钢

    2015-01-01

    主要简述脑小血管病(cerebral small vessel disease,SVD)与血管性认知功能障碍(vascular cognitive impair-ment,VCI)的关系。SVD 包括腔隙性脑梗死、脑微出血、脑白质病变或脑白质疏松三种类型,三者均与 VCI 密切相关,均可导致认知功能下降。因 SVD 起病隐袭,在临床工作中常被忽略,早发现、早干预 SVD 对预防 VCI 至关重要。%ABSTRACT:This paper reviews the relationship between cerebral small vessel disease (SVD)and vas-cular cognitive impairment (VCI).SVD includes lacunar infarction,cerebral microbleeds,and white mat-ter lesions or leukoaraiosis.The three types of SVD are closely correlated with VCI and can result in cog-nitive decline.Because of the insidious onset,SVD is often neglected in the clinical work.Therefore,early detection and intervention of SVD are very important for the prevention of VCI.

  6. Avaliação do desempenho funcional de crianças com paralisia cerebral de acordo com níveis de comprometimento motor Functional performance assessment of children with cerebral palsy according to motor impairment levels

    Directory of Open Access Journals (Sweden)

    Rosangela L. M. Vasconcelos

    2009-10-01

    Full Text Available CONTEXTUALIZAÇÃO: Diversos estudos têm avaliado a função motora de crianças com Paralisia Cerebral (PC, entretanto pouco se sabe sobre as inter-relações entre comprometimentos da mobilidade, autocuidado e função social relacionadas às habilidades funcionais da criança e à assistência do cuidador. OBJETIVOS: Identificar diferenças funcionais de crianças com PC em diferentes níveis de disfunção motora e correlacioná-las com os domínios mobilidade, autocuidado e função social na habilidade funcional e na assistência do cuidador. MÉTODOS: Realizou-se uma pesquisa analítica de corte transversal com 70 crianças/famílias, com idades de 4 a 7,5 anos, atendidas no Centro de Reabilitação Infantil, por meio do Pediatric Evaluation Disability Inventory (PEDI e do Gross Motor Function Classification System (GMFCS. A análise dos dados foi realizada por meio da ANOVA e teste de correlação de Pearson. RESULTADOS: Os resultados indicaram importante variabilidade funcional das crianças com PC em diferentes níveis de severidade da disfunção motora. Essa variação foi observada nos domínios mobilidade, autocuidado e função social. Os resultados apresentaram, também, forte correlação entre os domínios mobilidade e autocuidado e mobilidade e função social. CONCLUSÕES: Diante da variabilidade apresentada pelas crianças, percebe-se a necessidade de aplicação do PEDI e GMFCS, o que parece aumentar o entendimento sobre a relação entre funções motoras grossas e atividades da vida diária. Essa correlação demonstra o quanto a mobilidade é determinante para avaliar o desempenho funcional e orientar a prática terapêutica no sentido de desenvolver as potencialidades das crianças, bem como orientar o cuidador na estimulação.BACKGROUND: Several studies have evaluated motor function among children with cerebral palsy (CP, but little is known about how mobility impairment, self-care and social function interrelate

  7. Tubuloglomerular feedback dynamics and renal blood flow autoregulation in rats

    DEFF Research Database (Denmark)

    Holstein-Rathlou, N H; Wagner, A J; Marsh, D J

    1991-01-01

    To decide whether tubuloglomerular feedback (TGF) can account for renal autoregulation, we tested predictions of a TGF simulation. Broad-band and single-frequency perturbations were applied to arterial pressure; arterial blood pressure, renal blood flow and proximal tubule pressure were measured....... Data were analyzed by linear systems analysis. Broad-band forcings of arterial pressure were also applied to the model to compare experimental results with simulations. With arterial pressure as the input and tubular pressure, renal blood flow, or renal vascular resistance as outputs, the model......Hz in which, in addition, there are autonomous oscillations in TGF. Higher amplitude forcings in this band were attenuated by autoregulatory mechanisms, but low-amplitude forcings entrained the autonomous oscillations and provoked amplified oscillations in blood flow, showing an effect of TGF on whole kidney...

  8. A dynamic model of renal blood flow autoregulation

    DEFF Research Database (Denmark)

    Holstein-Rathlou, N H; Marsh, D J

    1994-01-01

    To test whether a mathematical model combining dynamic models of the tubuloglomerular feedback (TGF) mechanism and the myogenic mechanism was sufficient to explain dynamic autoregulation of renal blood flow, we compared model simulations with experimental data. To assess the dynamic characteristics...... nephrons act in parallel, each simulation was performed with 125 parallel versions of the model. The key parameters of the 125 versions of the model were chosen randomly within the physiological range. None of the constituent models, i.e., the TGF and the myogenic, could alone reproduce the experimental...... observations. However, in combination they reproduced most of hte features of the various transfer functions calculated from the experimental data. The major discrepancy was the presence of a bimodal distribution of the admittance phase in the simulations. This is not consistent with most of the experimental...

  9. A functional-structural modelling approach to autoregulation of nodulation.

    Science.gov (United States)

    Han, Liqi; Gresshoff, Peter M; Hanan, Jim

    2011-04-01

    Autoregulation of nodulation is a long-distance shoot-root signalling regulatory system that regulates nodule meristem proliferation in legume plants. However, due to the intricacy and subtleness of the signalling nature in plants, molecular and biochemical details underlying mechanisms of autoregulation of nodulation remain largely unknown. The purpose of this study is to use functional-structural plant modelling to investigate the complexity of this signalling system. There are two major challenges to be met: modelling the 3D architecture of legume roots with nodulation and co-ordinating signalling-developmental processes with various rates. Soybean (Glycine max) was chosen as the target legume. Its root system was observed to capture lateral root branching and nodule distribution patterns. L-studio, a software tool supporting context-sensitive L-system modelling, was used for the construction of the architectural model and integration with the internal signalling. A branching pattern with regular radial angles was found between soybean lateral roots, from which a root mapping method was developed to characterize the laterals. Nodules were mapped based on 'nodulation section' to reveal nodule distribution. A root elongation algorithm was then developed for simulation of root development. Based on the use of standard sub-modules, a synchronization algorithm was developed to co-ordinate multi-rate signalling and developmental processes. The modelling methods developed here not only allow recreation of legume root architecture with lateral branching and nodulation details, but also enable parameterization of internal signalling to produce different regulation results. This provides the basis for using virtual experiments to help in investigating the signalling mechanisms at work.

  10. No apparent role for T-type Ca²⁺ channels in renal autoregulation.

    Science.gov (United States)

    Frandsen, Rasmus Hassing; Salomonsson, Max; Hansen, Pernille B L; Jensen, Lars J; Braunstein, Thomas Hartig; Holstein-Rathlou, Niels-Henrik; Sorensen, Charlotte Mehlin

    2016-04-01

    Renal autoregulation protects glomerular capillaries against increases in renal perfusion pressure (RPP). In the mesentery, both L- and T-type calcium channels are involved in autoregulation. L-type calcium channels participate in renal autoregulation, but the role of T-type channels is not fully elucidated due to lack of selective pharmacological inhibitors. The role of T- and L-type calcium channels in the response to acute increases in RPP in T-type channel knockout mice (CaV3.1) and normo- and hypertensive rats was examined. Changes in afferent arteriolar diameter in the kidneys from wild-type and CaV3.1 knockout mice were assessed. Autoregulation of renal blood flow was examined during acute increases in RPP in normo- and hypertensive rats under pharmacological blockade of T- and L-type calcium channels using mibefradil (0.1 μM) and nifedipine (1 μM). In contrast to the results from previous pharmacological studies, genetic deletion of T-type channels CaV3.1 did not affect renal autoregulation. Pharmacological blockade of T-type channels using concentrations of mibefradil which specifically blocks T-type channels also had no effect in wild-type or knockout mice. Blockade of L-type channels significantly attenuated renal autoregulation in both strains. These findings are supported by in vivo studies where blockade of T-type channels had no effect on changes in the renal vascular resistance after acute increases in RPP in normo- and hypertensive rats. These findings show that genetic deletion of T-type channels CaV3.1 or treatment with low concentrations of mibefradil does not affect renal autoregulation. Thus, T-type calcium channels are not involved in renal autoregulation in response to acute increases in RPP.

  11. Kids' Quest: Vision Impairment

    Science.gov (United States)

    ... least one other developmental disability, such as intellectual disabilities, cerebral palsy, hearing loss, or epilepsy. Vision impairment is more common in older people than in children. Guide dogs are the guiding ...

  12. Patterns of synchrony for feed-forward and auto-regulation feed-forward neural networks.

    Science.gov (United States)

    Aguiar, Manuela A D; Dias, Ana Paula S; Ferreira, Flora

    2017-01-01

    We consider feed-forward and auto-regulation feed-forward neural (weighted) coupled cell networks. In feed-forward neural networks, cells are arranged in layers such that the cells of the first layer have empty input set and cells of each other layer receive only inputs from cells of the previous layer. An auto-regulation feed-forward neural coupled cell network is a feed-forward neural network where additionally some cells of the first layer have auto-regulation, that is, they have a self-loop. Given a network structure, a robust pattern of synchrony is a space defined in terms of equalities of cell coordinates that is flow-invariant for any coupled cell system (with additive input structure) associated with the network. In this paper, we describe the robust patterns of synchrony for feed-forward and auto-regulation feed-forward neural networks. Regarding feed-forward neural networks, we show that only cells in the same layer can synchronize. On the other hand, in the presence of auto-regulation, we prove that cells in different layers can synchronize in a robust way and we give a characterization of the possible patterns of synchrony that can occur for auto-regulation feed-forward neural networks.

  13. Ultrasonographic evaluation of cerebral arterial and venous haemodynamics in multiple sclerosis: a case-control study.

    Directory of Open Access Journals (Sweden)

    Pasquale Marchione

    Full Text Available OBJECTIVE: Although recent studies excluded an association between Chronic Cerebrospinal Venous Insufficiency and Multiple Sclerosis (MS, controversial results account for some cerebrovascular haemodynamic impairment suggesting a dysfunction of cerebral autoregulation mechanisms. The aim of this cross-sectional, case-control study is to evaluate cerebral arterial inflow and venous outflow by means of a non-invasive ultrasound procedure in Relapsing Remitting (RR, Primary Progressive (PP Multiple Sclerosis and age and sex-matched controls subjects. MATERIAL AND METHODS: All subjects underwent a complete extra-intracranial arterial and venous ultrasound assessment with a color-coded duplex sonography scanner and a transcranial doppler equipment, in both supine and sitting position by means of a tilting chair. Basal arterial and venous morphology and flow velocities, postural changes in mean flow velocities (MFV of middle cerebral arteries (MCA, differences between cerebral venous outflow (CVF in clinostatism and in the seated position (ΔCVF and non-invasive cerebral perfusion pressure (CPP were evaluated. RESULTS: 85 RR-MS, 83 PP-MS and 82 healthy controls were included. ΔCVF was negative in 45/85 (52.9% RR-MS, 63/83 (75.9% PP-MS (p = 0.01 and 11/82 (13.4% controls (p<0.001, while MFVs on both MCAs in sitting position were significantly reduced in RR-MS and PP-MS patients than in control, particularly in EDSS ≥ 5 subgroup (respectively, 42/50, 84% vs. 66/131, 50.3%, p<0.01 and 48.3 ± 2 cm/s vs. 54.6 ± 3 cm/s, p = 0.01. No significant differences in CPP were observed within and between groups. CONCLUSIONS: The quantitative evaluation of cerebral blood flow (CBF and CVF and their postural dependency may be related to a dysfunction of autonomic nervous system that seems to characterize more disabled MS patients. It's not clear whether the altered postural control of arterial inflow and venous outflow is a specific MS condition or simply an

  14. Ultrasonographic Evaluation of Cerebral Arterial and Venous Haemodynamics in Multiple Sclerosis: A Case-Control Study

    Science.gov (United States)

    Marchione, Pasquale; Morreale, Manuela; Giacomini, Patrizia; Izzo, Chiara; Pontecorvo, Simona; Altieri, Marta; Bernardi, Silvia; Frontoni, Marco; Francia, Ada

    2014-01-01

    Objective Although recent studies excluded an association between Chronic Cerebrospinal Venous Insufficiency and Multiple Sclerosis (MS), controversial results account for some cerebrovascular haemodynamic impairment suggesting a dysfunction of cerebral autoregulation mechanisms. The aim of this cross-sectional, case-control study is to evaluate cerebral arterial inflow and venous outflow by means of a non-invasive ultrasound procedure in Relapsing Remitting (RR), Primary Progressive (PP) Multiple Sclerosis and age and sex-matched controls subjects. Material and Methods All subjects underwent a complete extra-intracranial arterial and venous ultrasound assessment with a color-coded duplex sonography scanner and a transcranial doppler equipment, in both supine and sitting position by means of a tilting chair. Basal arterial and venous morphology and flow velocities, postural changes in mean flow velocities (MFV) of middle cerebral arteries (MCA), differences between cerebral venous outflow (CVF) in clinostatism and in the seated position (ΔCVF) and non-invasive cerebral perfusion pressure (CPP) were evaluated. Results 85 RR-MS, 83 PP-MS and 82 healthy controls were included. ΔCVF was negative in 45/85 (52.9%) RR-MS, 63/83 (75.9%) PP-MS (p = 0.01) and 11/82 (13.4%) controls (p<0.001), while MFVs on both MCAs in sitting position were significantly reduced in RR-MS and PP-MS patients than in control, particularly in EDSS≥5 subgroup (respectively, 42/50, 84% vs. 66/131, 50.3%, p<0.01 and 48.3±2 cm/s vs. 54.6±3 cm/s, p = 0.01). No significant differences in CPP were observed within and between groups. Conclusions The quantitative evaluation of cerebral blood flow (CBF) and CVF and their postural dependency may be related to a dysfunction of autonomic nervous system that seems to characterize more disabled MS patients. It's not clear whether the altered postural control of arterial inflow and venous outflow is a specific MS condition or simply an

  15. 成人缺血性脑血管病的认知损害特征分析%Characteristics of cognitive impairment in adults with cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    雷宇; 郭起浩; 李彦江; 江汉强; 倪伟; 顾宇翔

    2014-01-01

    卒中发生率差异无统计学意义(x2=1.111,P=0.574);所有30例缺血性脑卒中患者中,56.7%为VCI,VaMCI/VCI为58.8%;26例TIA患者中,61.5%为VCI,VaMCI/VCI为75.0%.结论 使用量表对成人缺血性脑血管病的认知损害特征进行分析不仅可加深对疾病的理解,同时为VCI的诊断标准和分型等进一步研究提供可靠依据.%Objective To explore the characteristics of cognitive impairment of cerebral ischemia in adults to provide rationales for proper diagnosis and targeted treatment.Methods A battery of standardized neuropsychological tests including mini-mental state examination (MMSE) and memory and executive screening (MES) was administered in a cohort of consecutive patients with cerebral ischemia.According to the screening results,they were divided into 3 subgroups of vascular dementia (VaD),vascular mild cognitive impairment (VaMCI) and non-vascular cognitive impairment (VCI).The general profiles of 3 subgroups were compared and the characteristics of VaMCI subgroup examined.Then the relationship between the composition of cognitive impairment and the type of ischemia (stroke and transient ischemic attack) was analyzed.Results Fifty-six patients and 48 healthy subjects (normal control group) matched with regards to age,gender and education were recruited.Compared to normal control group,there was a decline in the scores of MMSE [(25.0 ±5.6) vs (28.0 ± 1.4) ; t =2.695,P =0.007] and MES [(67 ±21) vs (84 ± 7) ; z =3.860,P =0.000] in case group.There were 33 cases (58.9%) of VCI in case group,including 11 (19.6%) in VaD subgroup,22 (39.3%) in VaMCI subgroup and 23 (41.1%) in non-VCI subgroup.And the rate of VaD/VaMCI was 1/2.The percentage of males (36.4% vs 78.3 % ; x2 =5.720,P =0.017) and education [(8 ± 3) vs (12 ± 4) ; P =0.010] of VaD subgroup were significantly lower than that of non-VCl subgroup; the education of VaMCI subgroup was significantly lower than that of non-VCI subgroup [(7 ± 3) vs

  16. Negative auto-regulation increases the input dynamic-range of the arabinose system of Escherichia coli

    Directory of Open Access Journals (Sweden)

    Bren Anat

    2011-07-01

    Full Text Available Abstract Background Gene regulation networks are made of recurring regulatory patterns, called network motifs. One of the most common network motifs is negative auto-regulation, in which a transcription factor represses its own production. Negative auto-regulation has several potential functions: it can shorten the response time (time to reach halfway to steady-state, stabilize expression against noise, and linearize the gene's input-output response curve. This latter function of negative auto-regulation, which increases the range of input signals over which downstream genes respond, has been studied by theory and synthetic gene circuits. Here we ask whether negative auto-regulation preserves this function also in the context of a natural system, where it is embedded within many additional interactions. To address this, we studied the negative auto-regulation motif in the arabinose utilization system of Escherichia coli, in which negative auto-regulation is part of a complex regulatory network. Results We find that when negative auto-regulation is disrupted by placing the regulator araC under constitutive expression, the input dynamic range of the arabinose system is reduced by 10-fold. The apparent Hill coefficient of the induction curve changes from about n = 1 with negative auto-regulation, to about n = 2 when it is disrupted. We present a mathematical model that describes how negative auto-regulation can increase input dynamic-range, by coupling the transcription factor protein level to the input signal. Conclusions Here we demonstrate that the negative auto-regulation motif in the native arabinose system of Escherichia coli increases the range of arabinose signals over which the system can respond. In this way, negative auto-regulation may help to increase the input dynamic-range while maintaining the specificity of cooperative regulatory systems. This function may contribute to explaining the common occurrence of negative auto-regulation

  17. Negative auto-regulation increases the input dynamic-range of the arabinose system of Escherichia coli.

    Science.gov (United States)

    Madar, Daniel; Dekel, Erez; Bren, Anat; Alon, Uri

    2011-07-12

    Gene regulation networks are made of recurring regulatory patterns, called network motifs. One of the most common network motifs is negative auto-regulation, in which a transcription factor represses its own production. Negative auto-regulation has several potential functions: it can shorten the response time (time to reach halfway to steady-state), stabilize expression against noise, and linearize the gene's input-output response curve. This latter function of negative auto-regulation, which increases the range of input signals over which downstream genes respond, has been studied by theory and synthetic gene circuits. Here we ask whether negative auto-regulation preserves this function also in the context of a natural system, where it is embedded within many additional interactions. To address this, we studied the negative auto-regulation motif in the arabinose utilization system of Escherichia coli, in which negative auto-regulation is part of a complex regulatory network. We find that when negative auto-regulation is disrupted by placing the regulator araC under constitutive expression, the input dynamic range of the arabinose system is reduced by 10-fold. The apparent Hill coefficient of the induction curve changes from about n = 1 with negative auto-regulation, to about n = 2 when it is disrupted. We present a mathematical model that describes how negative auto-regulation can increase input dynamic-range, by coupling the transcription factor protein level to the input signal. Here we demonstrate that the negative auto-regulation motif in the native arabinose system of Escherichia coli increases the range of arabinose signals over which the system can respond. In this way, negative auto-regulation may help to increase the input dynamic-range while maintaining the specificity of cooperative regulatory systems. This function may contribute to explaining the common occurrence of negative auto-regulation in biological systems.

  18. Relationship between silent cerebral small vessel disease and cognitive impairment%静止性脑小血管病与认知功能障碍的关系

    Institute of Scientific and Technical Information of China (English)

    李俊雯; 黄敬

    2014-01-01

    The imaging features of cerebral small vessel disease (CSVD) include 1acunar infarcts, white matter lesions, cerebral microbleeds. Silent CSVD is closely associated with cognitive impairment. The decline in executive function, processing speed and memory problem are the main performance of the cognitive dysfunction caused by silent CSVD, which is associated with focal areas, quantity and size. Here we summarize the imaging features of silent CSVD and the relationship between silent CSVD and cognitive impairment for the purpose of early recognition and management of silent CSVD so as to delay the onset and development of cognitive impairment and improve the patients’ quality of life.%脑小血管病(cerebral small vessel disease, CSVD)在影像学上主要以腔隙性梗死、白质病变和脑微出血的形态存在。静止性CSVD与认知功能障碍密切相关,其导致的认知功能障碍主要表现为执行功能障碍、反应迟钝和注意力下降等,与病灶部位、数量和大小相关。本文就静止性CSVD的主要影像学表现及其与认知功能障碍的关系作一综述,以期加深临床医生对静止性CSVD及其危害的认识并提高识别率,由此尽早干预而延缓患者认知功能障碍的发生和发展,提高患者的生活质量。

  19. Individual difficulties faced by persons with mobility impairments

    CSIR Research Space (South Africa)

    Greeff, M

    2007-07-01

    Full Text Available Standard everyday use – home computer user Advanced Advanced Advanced Disability Mobility impairment (quadriplegic – Frederik’s Ataxia), speech impairment) Mobility impairment (quadriplegic - Physical cerebral palsy, speech impairment) Mobility...

  20. Is arterial hypertension crucial for the development of cerebral haemorrhage in premature infants?

    DEFF Research Database (Denmark)

    Lou, H C; Lassen, N A; Friis-Hansen, B

    1979-01-01

    . It is suggested that premature neonates are hypertensive when their blood-pressure is compared with that in utero, and that events that lead to further rises in pressure are common. Their capillaries are not protected against rises in arterial pressure because autoregulation is impaired. Furthermore...

  1. Investigation of practices to support the complex communication needs of children with hearing impairment and cerebral palsy in a rural district of Kenya: a case series.

    Science.gov (United States)

    Bunning, Karen; Gona, Joseph K; Buell, Susan; Newton, Charles R; Hartley, Sally

    2013-01-01

    Rehabilitation services are scarce in low-income countries, where under-representation of some specialist professions has led to the role extension of others. An example of this can be found in Kilifi in Kenya where the role of speech and language therapy has been taken on by occupational therapists and teachers. To investigate the communication practices used by these professional groups to support children with complex communication needs in a rural part of Kenya and to explore the ways in which this might be seen to facilitate or obstruct improved communication by asking the following questions: What are the critical features of interactional discourse in practitioner-child dyads with caregiver-child dyads providing a natural comparison? What communicative modalities and practice techniques are invoked? And how does this information relate to extending professional roles? An in-depth, descriptive study of a case series was conducted in a school for deaf children and the occupational therapy department of a district general hospital. A mixed methodology was used involving naturalistic observation and applied linguistics analysis. A convenience sample was established comprising six practitioner-child dyads assigned to partnership types: (A) three children with hearing impairment and their teachers; and (B) three children with cerebral palsy and their occupational therapists. As a natural comparator, the same three children in B were also observed with their mothers (partnership type C). Dyadic interaction was video recorded on three occasions. The video data were sampled, transcribed into standard orthography and translated. Codes were applied to determine turn structure, linguistic move types and communicative modalities. Sequential analysis was conducted on the move types. Partnership type A dyads showed a fairly even turn distribution between teacher and child. A common pattern was teacher-initiated Instruct and Model/Prompt, followed by child response in the

  2. Brief Screening of Vascular Cognitive Impairment in Patients With Cerebral Autosomal-Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy Without Dementia

    OpenAIRE

    2016-01-01

    Background and Purpose - Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a monogenic form of cerebral small vessel disease leading to early-onset stroke and dementia, with younger patients frequently showing subclinical deficits in cognition. At present, there are no targeted cognitive screening measures for this population. However, the Brief Memory and Executive Test (BMET) and the Montreal Cognitive Assessment (MoCA) have shown utilit...

  3. Non-invasive assessment of cerebral microcirculation with diffuse optics and coherent hemodynamics spectroscopy

    Science.gov (United States)

    Fantini, Sergio; Sassaroli, Angelo; Kainerstorfer, Jana M.; Tgavalekos, Kristen T.; Zang, Xuan

    2016-03-01

    We describe the general principles and initial results of coherent hemodynamics spectroscopy (CHS), which is a new technique for the quantitative assessment of cerebral hemodynamics on the basis of dynamic near-infrared spectroscopy (NIRS) measurements. The two components of CHS are (1) dynamic measurements of coherent cerebral hemodynamics in the form of oscillations at multiple frequencies (frequency domain) or temporal transients (time domain), and (2) their quantitative analysis with a dynamic mathematical model that relates the concentration and oxygen saturation of hemoglobin in tissue to cerebral blood volume (CBV), cerebral blood flow (CBF), and cerebral metabolic rate of oxygen (CMRO2). In particular, CHS can provide absolute measurements and dynamic monitoring of CBF, and quantitative measures of cerebral autoregulation. We report initial results of CBF measurements in hemodialysis patients, where we found a lower CBF (54 +/- 16 ml/(100 g-min)) compared to a group of healthy controls (95 +/- 11 ml/(100 g-min)). We also report CHS measurements of cerebral autoregulation, where a quantitative index of autoregulation (its cutoff frequency) was found to be significantly greater in healthy subjects during hyperventilation (0.034 +/- 0.005 Hz) than during normal breathing (0.017 +/- 0.002 Hz). We also present our approach to depth resolved CHS, based on multi-distance, frequency-domain NIRS data and a two-layer diffusion model, to enhance sensitivity to cerebral tissue. CHS offers a potentially powerful approach to the quantitative assessment and continuous monitoring of local brain perfusion at the microcirculation level, with prospective brain mapping capabilities of research and clinical significance.

  4. Cerebral microcirculatory changes during pulsatile and non-pulsatile flow in hypovolemic hypotension

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Cerebral microcirculatory changes in hypovolemic hypotension we re investigat ed in rats with a cardio-pulmonary bypass (CPB) during pulsatile and non-pulsati le flow. The hypovolemic hypotension was induced by reducing the CPB flow-rate. In the non-pulsatile flow, the cardiac beat was stopped using a fibrilator, whi le in the pulsatile flow the cardiac function was retained. The pial microcircul ation was observed and recorded during CPB, using fluorescence videomicroscopy. The arteriolar diameter and red cell velocity were measured based on the recorde d videoimages. The flow-rate was calculated from the measured diameter and veloc ity data. The present results showed that the flow-rate remained almost constant up to 60 mmHg arterial pressure during pulsatile flow. On the other hand, in n on-pulsatile flow, the flow-rate decreased with a decrease in arterial pressure, indicating the impairment of microvascular autoregulation. It was suggested th at pulsatile flow has an advantage over non-pulsatile flow in a view-point of ce rebral microcirculatory changes in hypovolemic hypotension. Collaborating researchers: Drs. T. Yamakawa, S. Yamaguchi, Y. Ohnishi (National Cardiovascular Center, Osaka,Japan)

  5. Sympathetic influence on cerebral blood flow and metabolism during exercise in humans

    DEFF Research Database (Denmark)

    Seifert, Thomas; Secher, Niels H

    2011-01-01

    -oxidative carbohydrate uptake during exercise. Adrenaline appears to accelerate cerebral glycolysis through a beta2-adrenergic receptor mechanism since noradrenaline is without such an effect. In addition, the exercise-induced cerebral non-oxidative carbohydrate uptake is blocked by combined beta 1/2-adrenergic blockade......, but not by beta1-adrenergic blockade. Furthermore, endurance training appears to lower the cerebral non-oxidative carbohydrate uptake and preserve cerebral oxygenation during submaximal exercise. This is possibly related to an attenuated catecholamine response. Finally, exercise promotes brain health as evidenced......This review focuses on the possibility that autonomic activity influences cerebral blood flow (CBF) and metabolism during exercise in humans. Apart from cerebral autoregulation, the arterial carbon dioxide tension, and neuronal activation, it may be that the autonomic nervous system influences CBF...

  6. Correlation of cognitive impairment with ischemic stroke-inducing cerebral artery%缺血性卒中责任动脉与认知障碍的相关性研究

    Institute of Scientific and Technical Information of China (English)

    张卫; 恽晓平

    2014-01-01

    Objective To explore the correlation of cognitive impairment with ischemic strokeinducing cerebral artery,in order to predict and find the correlations between different cognitive dysfunction and different intracranial arterial occlusion.Methods We used Montreal Cognitive Assessment (MoCA) to evaluate neuropsychological statuses in the 250 patients,who developed first time acute myocardial infarction for 2 weeks.MoCA scores and other neuropsychological cognitive assessment scores were recorded.Patients were grouped by the location of intracranial arterial occlusion.The neuropsychological cognitive assessment results were analyzed between groups.Results Middle cerebral artery occlusion was correlated with impairments of visual spatial/executive,attention,language and memory (B=-1.875 ~-1.094,P<0.05).Anterior cerebral artery and vertebral basilar artery occlusion had correlations with attention impairment (B =-3.977,B =-1.833,P<0.01).Posterior cerebral artery occlusion could cause visual spatial/executive,language and memory impairment(B=-1.714 ~-1.095,P<0.05).No correlation of cognitive impairment characteristics with anterior choroidal artery occlusion was found.Conclusions Different arterial occlusion can cause different characteristics of impairment in cognitive function,which can help to predict cognitive impairment after sub-acute stroke.It suggests that some cognitive assessments must be conducted in sub-acute stroke management.%目的 从责任动脉角度探讨缺血性卒中与认知障碍之间的关系,寻找不同责任动脉阻塞所致的特征性认知领域损害及其内在联系以期及早预测认知障碍. 方法 应用蒙特利尔认知评估量表(MoCA)北京版,对250例首次急性发病2周左右的缺血性卒中患者进行认知功能评估,记录其MoCA评分及各单项认知领域评分.按阻塞责任动脉分组,将各组的MoCA认知评估结果进行相关分析. 结果 大脑中动脉供血区梗死与视空间/执行

  7. Negative auto-regulators trap p53 in their web.

    Science.gov (United States)

    Zhou, Xiang; Cao, Bo; Lu, Hua

    2017-01-09

    The transcriptional factor p53 activates the expression of a myriad of target genes involving a complicated signalling network, resulting in various cellular outcomes, such as growth arrest, senescence, apoptosis, and metabolic changes, and leading to consequent suppression of tumour growth and progression. Because of the profoundly adverse effect of p53 on growth and proliferation of cancer cells, several feedback mechanisms have been employed by the cells to constrain p53 activity. Two major antagonists MDM2 and MDMX (the long forms) are transcriptionally induced by p53, but in return block p53 activity, forming a negative feedback circuit and rendering chemoresistance of several cancer cells. However, they are not alone, as cancer cells also employ other proteins encoded by p53 target genes to inhibit p53 activity at transcriptional, translational, and posttranslational levels. This essay is thus composed to review a recent progress in understanding the mechanisms for how cancer cells hijack the p53 autoregulation by these proteins for their growth advantage and to discuss the clinical implications of these autoregulatory loops.

  8. Cooperativity of Negative Autoregulation Confers Increased Mutational Robustness

    Science.gov (United States)

    Marciano, David C.; Lua, Rhonald C.; Herman, Christophe; Lichtarge, Olivier

    2016-01-01

    Negative autoregulation is universally found across organisms. In the bacterium Escherichia coli, transcription factors often repress their own expression to form a negative feedback network motif that enables robustness to changes in biochemical parameters. Here we present a simple phenomenological model of a negative feedback transcription factor repressing both itself and another target gene. The strength of the negative feedback is characterized by three parameters: the cooperativity in self-repression, the maximal expression rate of the transcription factor, and the apparent dissociation constant of the transcription factor binding to its own promoter. Analysis of the model shows that the target gene levels are robust to mutations in the transcription factor, and that the robustness improves as the degree of cooperativity in self-repression increases. The prediction is tested in the LexA transcriptional network of E. coli by altering cooperativity in self-repression and promoter strength. Indeed, we find robustness is correlated with the former. Considering the proposed importance of gene regulation in speciation, parameters governing a transcription factor’s robustness to mutation may have significant influence on a cell or organism’s capacity to evolve. PMID:27391757

  9. Cooperativity of Negative Autoregulation Confers Increased Mutational Robustness

    Science.gov (United States)

    Marciano, David C.; Lua, Rhonald C.; Herman, Christophe; Lichtarge, Olivier

    2016-06-01

    Negative autoregulation is universally found across organisms. In the bacterium Escherichia coli, transcription factors often repress their own expression to form a negative feedback network motif that enables robustness to changes in biochemical parameters. Here we present a simple phenomenological model of a negative feedback transcription factor repressing both itself and another target gene. The strength of the negative feedback is characterized by three parameters: the cooperativity in self-repression, the maximal expression rate of the transcription factor, and the apparent dissociation constant of the transcription factor binding to its own promoter. Analysis of the model shows that the target gene levels are robust to mutations in the transcription factor, and that the robustness improves as the degree of cooperativity in self-repression increases. The prediction is tested in the LexA transcriptional network of E. coli by altering cooperativity in self-repression and promoter strength. Indeed, we find robustness is correlated with the former. Considering the proposed importance of gene regulation in speciation, parameters governing a transcription factor's robustness to mutation may have significant influence on a cell or organism's capacity to evolve.

  10. Basal forebrain thermoregulatory mechanism modulates auto-regulated sleep

    Directory of Open Access Journals (Sweden)

    Hruda N Mallick

    2012-06-01

    Full Text Available Regulation of body temperature and sleep are two physiological mechanisms that are vital for our survival. Interestingly neural structures implicated in both these functions are common. These areas include the medial preoptic area, the lateral preoptic area, the ventrolateral preoptic area, the median preoptic nucleus and the medial septum, which form part of the basal forebrain.When given a choice, rats prefer to stay at an ambient temperature of 270C, though the maximum sleep was observed when they were placed at 300C. Ambient temperature around 270C should be considered as the thermoneutral temperature for rats in all sleep studies. At this temperature the diurnal oscillations of sleep and body temperature are properly expressed. The warm sensitive neurons of the preoptic area mediate the increase in sleep at 300C. Promotion of sleep during the rise in ambient temperature from 270C to 300C, serve a thermoregulatory function. Autonomous thermoregulatory changes in core body temperature and skin temperature could act as an input signal to modulate neuronal activity in sleep-promoting brain areas. The studies presented here show that the neurons of the basal forebrain play a key role in regulating sleep. Basal forebrain thermoregulatory system is a part of the global homeostatic sleep regulatory mechanism, which is auto-regulated.

  11. Observation of curative effect of early intervention for children with cerebral palsy of cognitive impairment%脑瘫儿童认知障碍早期干预的疗效观察

    Institute of Scientific and Technical Information of China (English)

    靳玉洁; 黄茂; 杨路平; 李小平

    2014-01-01

    Objective:To explore the curative effect of early intervention for children with cerebral palsy of cognitive impairment. Methods:121 children with cerebral palsy combined with speech disorder were selected from December 2010 to December 2012. They were randomLy divided into the treatment group with 64 cases and the control group with 57 cases.The control group were given basic treatment and speech training.The treatment group were given acupuncture therapy based on the treatment in control group.We compared the therapeutic effect of 2 groups.Results:In the two group,there was significant difference in efficacy of patients aged from 1 to 3 years old and from 3 to 6 years old(P<0.05).Conclusion:The curative effect of early intervention for children with cerebral palsy of cognitive impairment is significant.%目的:探讨脑瘫儿童认知障碍早期干预的疗效。方法:2010年12月-2012年12月收治脑瘫合并言语障碍患儿121例,随机分为治疗组64例和对照组57例,对照组做基础治疗和言语训练,治疗组在对照组治疗基础上加做头针治疗,比较两组的治疗效果。结果:两组中1~3岁与3~6岁患儿疗效差异有统计学意义(P<0.05)。结论:脑瘫儿童认知障碍早期干预疗效显著。

  12. Middle cerebral artery blood velocity during running.

    Science.gov (United States)

    Lyngeraa, T S; Pedersen, L M; Mantoni, T; Belhage, B; Rasmussen, L S; van Lieshout, J J; Pott, F C

    2013-02-01

    Running induces characteristic fluctuations in blood pressure (BP) of unknown consequence for organ blood flow. We hypothesized that running-induced BP oscillations are transferred to the cerebral vasculature. In 15 healthy volunteers, transcranial Doppler-determined middle cerebral artery (MCA) blood flow velocity, photoplethysmographic finger BP, and step frequency were measured continuously during three consecutive 5-min intervals of treadmill running at increasing running intensities. Data were analysed in the time and frequency domains. BP data for seven subjects and MCA velocity data for eight subjects, respectively, were excluded from analysis because of insufficient signal quality. Running increased mean arterial pressure and mean MCA velocity and induced rhythmic oscillations in BP and in MCA velocity corresponding to the difference between step rate and heart rate (HR) frequencies. During running, rhythmic oscillations in arterial BP induced by interference between HR and step frequency impact on cerebral blood velocity. For the exercise as a whole, average MCA velocity becomes elevated. These results suggest that running not only induces an increase in regional cerebral blood flow but also challenges cerebral autoregulation. © 2012 John Wiley & Sons A/S.

  13. A single subcutaneous bolus of erythropoietin normalizes cerebral blood flow autoregulation after subarachnoid haemorrhage in rats

    DEFF Research Database (Denmark)

    Springborg, Jacob Bertram; Ma, XiaoDong; Rochat, Per;

    2002-01-01

    Systemic administration of recombinant erythropoietin (EPO) has been demonstrated to mediate neuroprotection. This effect of EPO may in part rely on a beneficial effect on cerebrovascular dysfunction leading to ischaemic neuronal damage. We investigated the in vivo effects of subcutaneously...

  14. Malaria cerebral Cerebral malaria

    OpenAIRE

    Carlos Hugo Zapata Zapata; Silvia Blair Trujillo

    2003-01-01

    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 citoqu...

  15. Reabilitação de déficits comunicativos pós-acidente vascular cerebral Rehabilitation of post-stroke communication impairments

    Directory of Open Access Journals (Sweden)

    Gigiane Gindri

    2012-01-01

    Full Text Available Os processamentos comunicativos discursivo, léxico-semântico, pragmático-inferencial e/ou prosódico podem apresentar-se deficitários após um acidente vascular cerebral. Esses prejuízos demandam métodos e programas de intervenção para uma reabilitação efetiva da comunicação. Neste contexto, o objetivo desta revisão sistemática foi identificar e descrever métodos utilizados para reabilitação neuropsicológica da comunicação de adultos acometidos por lesão cerebrovascular, mais especificamente, abordagens sistematizadas de intervenção para cada um dos processamentos comunicativos. Foram avaliados resumos publicados nos últimos dez anos na base de dados PubMed, utilizando palavras-chave relacionadas aos construtos reabilitação, acidente vascular cerebral (AVC e comunicação. Para o construto comunicação foram utilizadas, ainda, palavras específicas dos quatro processamentos comunicativos. Inicialmente, foram encontrados 914 abstracts, dos quais, após exclusão dos repetidos, 460 foram analisados. Os critérios de inclusão de abstracts para análise de seus textos completos foram ser estudo empírico, ter a participação de pelo menos um indivíduo adulto pós-AVC, tratar de reabilitação da comunicação, apresentar intervenção para pelo menos um dos quatro processamentos comunicativos, ter avaliação pré e pós-tratamento, estar escrito em inglês, francês ou português, e ter sido publicado nos últimos dez anos. Apenas quatro artigos empíricos cumpriram tais critérios, sendo conduzidos predominantemente com adultos afásicos ou com aprosódia. Assim, tais achados podem ser considerados surpreendentes e alarmantes frente à escassez de estudos sistemáticos de reabilitação de componentes comunicativos. Ressalta-se a necessidade de descrição detalhada de procedimentos de intervenção com objetivos específicos para que estudos possam ser replicados, contribuindo também para a verificação do efeito

  16. Mathematical model for blood flow autoregulation by endothelium-derived relaxing factor

    CERN Document Server

    Chernyavsky, I L; Chernyavsky, Igor L.; Kudryashov, Nikolai A.

    2006-01-01

    The fluid shear stress is an important regulator of the cardiovascular system via the endothelium-derived relaxing factor (EDRF) that is Nitric Oxide. This mechanism involves biochemical reactions in an arterial wall. The autoregulation process is managed by the vascular tonus and gives the negative feedback for the shear stress changing. A new mathematical model for the autoregulation of a blood flow through arteria under the constant transmural pressure is presented. Endothelium-derived relaxing factor Nitric Oxide, the multi-layer structure of an arterial wall, and kinetic-diffusion processes are taken into consideration. The limit case of the thin-wall artery is analytically studied. The stability condition for a stationary point of the linearized system is given. The exact stationary solutions of the origin system are found. The numerical simulation for the autoregulation system is presented. It is shown the arteria adaptation to an initial radial perturbation and the transition of the system to new equi...

  17. Regional Cerebral Blood Flow in [123]I-IMP Single-photon Emission Computed Tomography and the Wechsler Memory Scale-revised in Nondemented Elderly Subjects with Subjective Cognitive Impairment.

    Science.gov (United States)

    Niwa, Fumitoshi; Kondo, Masaki; Sakurada, Kumi; Nakagawa, Masanori; Imanishi, Jiro; Mizuno, Toshiki

    Objective Regional cerebral blood flow (rCBF) imaging with single-photon emission computed tomography (SPECT) is useful in the early diagnosis of dementia. We aimed to investigate the association between the rCBF and various domains related to the memory function in elderly subjects with subjective cognitive impairment (SCI). Methods Thirty-two subjects with SCI were included in the present study. Patients with dementia and mild cognitive impairment (MCI) were excluded based on the presence of logical memory impairment. N-isopropyl-p-[(123)I]-iodoamphetamine SPECT was performed and Wechsler Memory Scale-Revised (WMS-R) was administered to all subjects (mean age, 68.4 years; average Mini-Mental State Examination score, 27.6). The SPECT results were analyzed using the easy Z-score imaging system and the voxel-based stereotactic extraction estimation method. Correlation analyses were performed to investigate the correlation between the mean positive Z-scores in the decrease of the rCBF and the WMS-R indices. Results The SPECT study indicated marked hypoperfusion in some areas, including the bilateral temporal areas, the caudate, and the thalamus, in these subjects in comparison to the normal database. The decrease in the rCBF that was observed in several regions, including the left precuneus and left inferior frontal gyrus (LIFG), showed a significant negative correlation with several indices of the memory function, particularly visual memory. Conclusion The regional hypoperfusion observed in the study using the voxel-based stereotactic extraction estimation method suggest that the regional cerebral dysfunction is associated with the memory function of patients with SCI, even though the subjects in the present study were cognitively intact. The correlation analysis with the WMS-R suggested the contribution of the LIFG to the memory function and indicated the significance of visual memory dysfunction in the neuropsychological assessment to determine the stage of SCI.

  18. Ataque cerebral

    OpenAIRE

    Takeuchi Tan, Yuri; Fundación Valle de Lili

    1998-01-01

    ¿Qué es un ataque cerebral?/¿Qué tipos de ataque cerebral existen?/¿Cuáles son los síntomas de un ataque cerebral?/Factores de riesgo para un ataque cerebral/Tratamiento médico del ataque cerebral/¿por qué es importante acudir temprano cuando se presentan las señales de alarma?/ Manejo preventivo del ataque cerebral isquémico/Tratamiento quirúrgico del ataque cerebral/Enfermedad vascular cerebral hemorrágica/¿Cómo está constituido el grupo de ataque cerebral de la fundación Clínica Valle d...

  19. Ataque cerebral

    OpenAIRE

    Takeuchi Tan, Yuri; Fundación Valle de Lili

    1998-01-01

    ¿Qué es un ataque cerebral?/¿Qué tipos de ataque cerebral existen?/¿Cuáles son los síntomas de un ataque cerebral?/Factores de riesgo para un ataque cerebral/Tratamiento médico del ataque cerebral/¿por qué es importante acudir temprano cuando se presentan las señales de alarma?/ Manejo preventivo del ataque cerebral isquémico/Tratamiento quirúrgico del ataque cerebral/Enfermedad vascular cerebral hemorrágica/¿Cómo está constituido el grupo de ataque cerebral de la fundación Clínica Valle d...

  20. Clinical and neuroradiological studies of eclampsia. Cerebral vasospasm and relation to the brain edema

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Yasuhiro; Niwa, Hisayoshi; Ando, Tetsuo; Yasuda, Takeshi; Yanagi, Tsutomu [Nagoya Daini Red Cross Hospital, Aichi (Japan)

    1995-04-01

    Clinical and neuroradiological studies involving cerebral angiography were conducted in four patients with eclampsia. In three cases (case 1, 2 and 4), neurological focal signs, abnormal low density areas on cranial CT and T{sub 2} high intensity areas on cranial MRI disappeared within a month. But in one case (case 3), cerebral infarction occurred and right hemiparesis and aphasia persisted. Cerebral angiography in the acute phase demonstrated vasospasm in all cases and arterial occlusion in the middle cerebral artery due to vasospasm in case 3. Angiography demonstrated several types of spasms, including diffuse, peripheral and multi local. Furthermore, in some cases, diffuse vasospasms were recognized at the siphon and extracranial portions of the internal carotid artery. In one case (Case 4), segmental vasospasms were detected in the bilateral vertebral arteries. Three to four weeks later, follow-up cerebral angiography was performed in three cases. Cerebral vasospasms had partially or completely recovered. Subarachnoid hemorrhage (SAH) was excluded by lumbar puncture and neuroradiological findings in all cases. We concluded that eclampsia itself causes cerebral vasospasm and that the mechanism of vasospasm is different from that of SAH, since cerebral vasospasm occurred in the extracranial cerebral arteries. We suspected that cerebral vasospasm in eclampsia causes cerebral ischemia, which leads to cytotoxic edema and dysfunction of the blood-brain barrier (BBB) and cerebral autoregulation. With this background, brain edema, especially vasogenic edema, may easily occur and clinical symptoms of eclampsia may appear when the blood pressure rapidly increases. (author).

  1. Application of Gaussian moment method to a gene autoregulation model of rational vector field

    Science.gov (United States)

    Kang, Yan-Mei; Chen, Xi

    2016-07-01

    We take a lambda expression autoregulation model driven by multiplicative and additive noises as example to extend the Gaussian moment method from nonlinear stochastic systems of polynomial vector field to noisy biochemical systems of rational polynomial vector field. As a direct application of the extended method, we also disclose the phenomenon of stochastic resonance. It is found that the transcription rate can inhibit the stochastic resonant effect, but the degradation rate may enhance the phenomenon. These observations should be helpful in understanding the functional role of noise in gene autoregulation.

  2. Autoregulation of Sinorhizobium meliloti exoR gene expression.

    Science.gov (United States)

    Lu, Hai-Yang; Cheng, Hai-Ping

    2010-07-01

    The successful nitrogen-fixing symbiosis between the gram-negative soil bacterium Sinorhizobium meliloti and its leguminous plant host alfalfa (Medicago sativa) requires the bacterial exopolysaccharide succinoglycan. Succinoglycan and flagellum production, along with the ability to metabolize more than 20 different carbon sources and control the expression of a large number of S. meliloti genes, is regulated by the ExoR-ExoS/ChvI signalling pathway. The ExoR protein interacts with and suppresses the sensing activities of ExoS, the membrane-bound sensor of the ExoS/ChvI two-component regulatory system. Here we show that exoR expression is clearly upregulated in the absence of any functional ExoR protein. This upregulation was suppressed by the presence of the wild-type ExoR protein but not by a mutated ExoR protein lacking signal peptide. The levels of exoR expression could be directly modified in real time by changing the levels of total ExoR protein. The expression of exoR was also upregulated by the constitutively active sensor mutation exoS96, and blocked by two single mutations, exoS* and exoS(supA), in the ExoS sensing domain. Presence of the wild-type ExoS protein further elevated the levels of exoR expression in the absence of functional ExoR protein, and reversed the effects of exoS96, exoS* and exoS(supA) mutations. Altogether, these data suggest that ExoR protein autoregulates exoR expression through the ExoS/ChvI system, allowing S. meliloti cells to maintain the levels of exoR expression based on the amount of total ExoR protein.

  3. 线粒体脑肌病伴高乳酸血症和卒中样发作患者的血管自主调节功能%Evaluation of vascular autoregulation in mitochondrial myopathy, encephalopathy, lactic acidosis,and stroke-like episodes patients

    Institute of Scientific and Technical Information of China (English)

    陈靖; 赵丹华; 王朝霞; 彭清; 袁云; 黄一宁

    2012-01-01

    Objective To investigate the cerebral vascular autoregulation in patients with mitochondrial encephalomyopathy with lactic acidosis and strokc-like episodes (MELAS) during the remission of stroke-like episodes,including cerebrovascular CO2 reactivity and vascular endothelial function.Methods Twenty-nine MELAS patients confirmed by genetic analysis were recruited in this study. They underwent the examination at least 2 weeks after the onset of last stroke-like episode.Twenty-eight healthy people were collcctcd as healthy controls. Carotid ultrasound and brain magnetic resonance angiogram (MRA) were done to evaluate the cervical and intracranial appearance of large arteries. Evaluation of vascular autoregulation included: (1) the cerebrovascular CO2 reactivity with breath-holding test by transcranial Doppler and calculating breath holding index (BHI),and ( 2 ) flow-mediatcd dilation ( FMD )and nitroglycerin-mediated dilation with ultrasound assessment of humeral artery.Independent-samples t test was done between the results of two groups.Results Carotid ultrasound and cranial MRA revealed no abnormalities in both MELAS patients and healthy controls.The BHI of MELAS patients was significantly decreased than that of normal controls ( 1.36 ± 0.52 vs 1.81 ±0.26,t =- 3.693,P < 0.01 ),and the FMD of MELAS patients was also significantly lower than that of normal controls (11.0% ±4.8% vs 15.8% ±5.8%,t =-3.390,P <0.01).Conclusion The function of vascular autoregulation,including cerebrovascular CO2 reactivity and FMD,is impaired in MELAS patients.%目的 评价线粒体脑肌病伴高乳酸血症和卒中样发作(MELAS)患者的脑血管二氧化碳(CO2)反应性和血管内皮功能,以分析患者在卒中样发作缓解期的血管自主调节功能变化.方法以经基因诊断证实的29例MELAS为患者组,检查时间距离末次卒中样发作的时间大于2周;健康志愿者28名为对照组.应用颈部血管彩超和头颅磁共振血管成

  4. 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 ...

  5. The plasma membrane redox system is impaired by amyloid β-peptide and in the hippocampus and cerebral cortex of 3xTgAD mice

    OpenAIRE

    Hyun, Dong-Hoon; Mughal, Mohamed R.; Yang, Hyunwon; Lee, Ji Hyun; Ko, Eun Joo; Hunt, Nicole D.; de Cabo, Rafael; Mattson, Mark P.

    2010-01-01

    Membrane-associated oxidative stress has been implicated in the synaptic dysfunction and neuronal degeneration that occurs in Alzheimer’s disease (AD), but the underlying mechanisms are unknown. Enzymes of the plasma membrane redox system (PMRS) provide electrons for energy metabolism and recycling of antioxidants. Here, we show that activities of several PMRS enzymes are selectively decreased in plasma membranes from the hippocampus and cerebral cortex of 3xTgAD mice, an animal model of AD. ...

  6. 首次脑梗死后患者认知功能障碍的多因素相关研究%Study on the related factors of cognitive impairment in cerebral infarction patients with first attack

    Institute of Scientific and Technical Information of China (English)

    刘涵; 程言博; 樊红彬; 耿德勤

    2011-01-01

    目的 探讨首次脑梗死后患者发生认知功能障碍的相关因素.方法 采用CT或MRI确定首次脑梗塞患者282例,所有患者均为右利手.病灶部位:额叶53例,顶叶45例,颞叶50例,枕叶43例,丘脑33例,基底节174例,小脑30例,脑干51例;测定病灶体积;采用中文版蒙特利尔认知评估量表(MOCA)、汉密顿抑郁量表(HAMD)评定患者的认知功能.结果 ①额叶、顶叶、颞叶、枕叶、丘脑、基底节梗死与认知功能障碍的发生具有相关性(P<0.05).小脑、脑干梗死与认知功能障碍无相关性.②病灶体积大小与认知功能障碍呈显著相关性(P<0.05).③ MOCA总分与HAMD分值呈显著性负相关(P<0.05).认知功能正常组与异常组的HAMD得分有显著性差异(P<0.05).④首次卒中后有认知功能损害者呈低文化水平特征,有长期大量饮酒史患者认知功能障碍有显著性异常(P<0.05).结论 认知功能障碍是首次脑梗死患者的常见并发症,认知功能障碍与卒中部位及体积有关,病灶体积大者认知功能障碍严重,教育水平低、长期大量饮酒及抑郁患者更易发生认知障碍.%Objective To study the related factors of cognitive impairment in cerebral infarction patients with first attack. Methods The lesion volumes and locations (frontal lobe 53 cases, parietal lobe 45 cases, temporal lobe 50 cases, occipital lobe 43 cases, thalamus 33 cases, basal ganglia 174 cases, cerebellum 30 cases and brainstem 8 cases) in patients (n =282) were measured by using CT/MRI techniques (all the patients were right- handed); Cognitive function were tested with Montreal Cognitive Assessment (MOCA) and Hamilton Depression Scale (HAMD). Results ① Cerebral infarction locus in frontal lobe, parietal lobe, temporal lobe, occipital lobe, thalamus and basal ganglia had correlation with obvious cognitive function impairment ( P < 0.05). While,cerebral infarction of cerebellum and brainstem had no correlation with cognitive

  7. Cerebral malaria Malaria cerebral

    OpenAIRE

    Silvia Blair Trujillo; Carlos Hugo Zapata Zapata

    2003-01-01

    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...

  8. Less efficient elementary visuomotor processes in 7- to 10-year-old preterm-born children without cerebral palsy : An indication of impaired dorsal stream processes

    NARCIS (Netherlands)

    Van Braeckel, K.N.J.A.; Butcher, P.R.; Geuze, R.H.; van Duijn, M.A.J.; Bos, Arie; Bouma, A

    2008-01-01

    Follow-up studies of preterm children without serious neurological complications have consistently found deficits in visuomotor skills. To determine whether these deficits may be related to impaired elementary visuomotor processes, we investigated movement programming and execution of simple pointin

  9. Cerebral malaria Malaria cerebral

    Directory of Open Access Journals (Sweden)

    Silvia Blair Trujillo

    2003-03-01

    Full Text Available 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. 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.

  10. INCREASE OF THETA FREQUENCY IS ASSOCIATED WITH REDUCTION IN REGIONAL CEREBRAL BLOOD FLOW ONLY IN SUBJECTS WITH MILD COGNITIVE IMPAIRMENT WITH HIGHER UPPER ALPHA/LOW ALPHA EEG FREQUENCY POWER RATIO

    Directory of Open Access Journals (Sweden)

    Davide v Moretti

    2013-12-01

    Full Text Available Background: several biomarkers have been proposed for detecting Alzheimer's disease (AD in its earliest stages, that is, in the predementia stage. In an attempt to find noninvasive biomarkers, researchers have investigated the feasibility of neuroimaging tools, such as MRI, SPECT as well as neurophysiological measurements using EEG. Moreover, the increase of EEG alpha3/alpha2 frequency power ratio has been associated with AD-converters subjects with mild cognitive impairment (MCI.Objective: to study the association of alpha3/alpha2 frequency power ratio with regional cerebral blood flow (rCBF changes in subjects with MCI .Methods: 27 adult subjects with MCI underwent EEG recording and perfusion single-photon emission computed tomography (SPECT evaluation. The alpha3/alpha2 frequency power ratio was computed for each subject. Two groups were obtained according to the median values of alpha3/alpha2, at a cut-off of 1.17. Correlation between brain perfusion and EEG markers were detected.Results: subjects with higher alpha3/alpha2 frequency power ratio showed a constant trend to a lower perfusion than low alpha3/alpha2 group. The two groups were significantly different as about the hippocampal volume and correlation with the theta frequency activity.Conclusion: there is a complex interplay between cerebral blood flow, theta frequency activity and hippocampal volume in MCI patients with prodromal Alzheimer's disease, characterized by higher EEG alpha3 /alpha2 frequency power ratio.

  11. Correlation of Cognitive Impairment and Areas of Middle Cerebral Artery Territory Infarction%大脑中动脉供血区不同梗死灶所致认知障碍的特点

    Institute of Scientific and Technical Information of China (English)

    张卫; 恽晓平; 于一宁

    2014-01-01

    目的:从大脑中动脉供血区角度探讨不同梗死部位缺血性卒中与认知障碍之间的关系。方法应用蒙特利尔认知评估量表(MoCA)北京版,对首次急性发病2周左右的缺血性卒中患者进行认知功能评估,记录其MoCA评分及各单项认知领域评分。按照大脑中动脉供血区梗死,MoCA评分≥15分,且至少有一个认知领域障碍的条件,筛选出132例患者资料。再按梗死部位分组,将各组MoCA结果进行相关分析。结果大脑中动脉供血区梗死与视空间/执行、注意、语言和记忆损害有关(B=-1.875~-1.094, P<0.05)。额叶梗死与视空间/执行、注意、抽象和记忆功能损害有关(B=-1.760~-1.329, P<0.05);颞叶梗死引起视空间/执行和记忆功能损害显著(B=-1.849~-1.735, P<0.05);顶叶梗死导致视空间/执行、注意和记忆功能损害(B=-1.695~-1.482, P<0.05);基底节梗死与视空间/执行、注意、语言和记忆功能损害有关(B=-1.932~-1.041, P<0.01)。结论大脑中动脉不同供血区梗死所致认知功能损害的领域不同。%Objective To explore the correlation of cognitive impairment and areas of middle cerebral artery (MCA) territory infarction. Methods The Montreal Cognitive Assessment (MoCA) was used to evaluate neuropsychological statuses in the patients who developed first-time acute cerebral infarction for 2 weeks. MoCA scores and sub-scores were recorded. 132 patients were selected with MCA occlu-sion, scores of MoCA were more than 15, and cognitive impairment in at least one domain, and then subgrouped by infarction site. The cor-relation between the results of neuropsychological cognitive assessment and the sites of infarction was analyzed. Results MCA occlusion was correlated with the impairments of visual spatial/executive, attention, language and memory (B=-1.875~-1.094, P<0.05). Infarction in frontal lobe was correlated with the impairments of visual spatial/executive, attention

  12. Synchronization among Mechanisms of Renal Autoregulation is Reduced in Hypertensive Rats

    DEFF Research Database (Denmark)

    Sosnovtseva, Olga; Pavlov, A. N.; Mosekilde, Erik;

    2007-01-01

    We searched for synchronization among autoregulation mechanisms using wavelet transforms applied to tubular pressure recordings in nephron pairs from the surface of rat kidneys. Nephrons have two oscillatory modes in the regulation of their pressures and flows: a faster (100-200 mHz) myogenic mode...

  13. On the efficacy of linear system analysis of renal autoregulation in rats

    DEFF Research Database (Denmark)

    Chon, K H; Chen, Y M; Holstein-Rathlou, N H;

    1993-01-01

    In order to assess the linearity of the mechanisms subserving renal blood flow autoregulation, broad-band arterial pressure fluctuations at three different power levels were induced experimentally and the resulting renal blood flow responses were recorded. Linear system analysis methods were...

  14. Long-lasting spatial learning and memory impairments caused by chronic cerebral hypoperfusion associate with a dynamic change of HCN1/HCN2 expression in hippocampal CA1 region.

    Science.gov (United States)

    Luo, Pan; Lu, Yun; Li, Changjun; Zhou, Mei; Chen, Cheng; Lu, Qing; Xu, Xulin; He, Zhi; Guo, Lianjun

    2015-09-01

    Chronic cerebral hypoperfusion (CCH) causes learning and memory impairments and increases the risk of Alzheimer disease (AD) and vascular dementia (VD) through several biologically plausible pathways, yet the mechanisms underlying the disease process remained unclear particularly in a temporal manner. We performed permanent bilateral occlusion of the common carotid arteries (two-vessel occlusion, 2VO) to induce CCH. To determine whether hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are altered at different stages of cognitive impairment caused by CCH, adult male SD rats were randomly distributed into sham-operated 4, 8 and 12weeks group, 2VO 4, 8 and 12weeks group. Learning and memory performance were evaluated with Morris water maze (MWM) and long-term potentiation (LTP) was used to address the underlying synaptic mechanisms. Expression of NeuN, HCN1 and HCN2 in hippocampal CA1, DG and CA3 areas was quantified by immunohistochemistry and western blotting. Our data showed that CCH induced a remarkable spatial learning and memory deficits in rats of 2VO 4, 8, and 12weeks group although neuronal loss only occurred after 4weeks of 2VO surgery in CA1. In addition, a significant reduction of HCN1 surface expression in CA1 was observed in the group that suffered 4weeks ischemia but neither 8 nor 12weeks. However, HCN2 surface expression in CA1 increased throughout the ischemia time-scales (4, 8 and 12w). Our findings indicate spatial learning and memory deficits in the CCH model are associated with disturbed HCN1 and HCN2 surface expression in hippocampal CA1. The altered patterns of both HCN1 and HCN2 surface expression may be implicated in the early stage (4w) of spatial learning and memory impairments; and the stable and long-lasting impairments of spatial learning and memory may partially attribute to the up-regulated HCN2 surface expression.

  15. 老年缺血性脑卒中后轻度血管性认知障碍的影响因素%The factors of mild vascular cognitive impairment in elderly patients with ischemic cerebral stroke

    Institute of Scientific and Technical Information of China (English)

    王和平; 黄燕秋

    2016-01-01

    目的:分析老年缺血性脑卒中后轻度血管性认知障碍(VCI)的影响因素。方法对患者一般资料、体格检查、认知评估及影像学资料进行收集与调查,并行单因素分析与Logistic回归分析。结果老年缺血性卒中后轻度VCI的发生与患者年龄、文化程度、冠心病、糖尿病、高血压、卒中次数、发病部位及卒中面积有关;与性别、BM I、吸烟、饮酒等无明显相关。Logistic回归分析显示,文化程度为老年缺血性脑卒中后轻度VCI发生的保护因素,而年龄、冠心病、糖尿病、高血压、卒中次数、发病部位及卒中面积是危险因素。结论老年缺血性脑卒中后轻度 VCI发生的危险因素众多,临床上可进行针对性的早期干预。%Objective To analyze the factors of mild vascular cognitive impairment (VCI) in elderly patients with ischemic cerebral stroke. Methods The general information ,physical examination ,cognitive evaluation and imaging data were collected and investigated;single factor analysis and Logistic regression analysis were used. Results The occurrence of mild VCI in eld-erly patients with ischemic cerebral stroke was related with age ,educational level ,coronary heart disease ,diabetes ,hyperten-sion ,stroke frequency ,disease location and area of stroke ,and had non-obvious relation with sex ,BMI ,smoking ,alcohol con-sumption. Logistic regression analysis showed that education was a protective factor for mild VIC in elderly patients with is-chemic cerebral stroke ,and age ,coronary heart disease ,diabetes ,hypertension ,stroke frequency ,disease location and area were the risk factors. Conclusion The risk factors for mild VCI in elderly patients with ischemic cerebral stroke are many ;targeted early intervention can be applied in clinic.

  16. Pentosan polysulfate treatment preserves renal autoregulation in ANG II-infused hypertensive rats via normalization of P2X1 receptor activation.

    Science.gov (United States)

    Guan, Zhengrong; Fuller, Barry S; Yamamoto, Tatsuo; Cook, Anthony K; Pollock, Jennifer S; Inscho, Edward W

    2010-05-01

    Inflammatory factors are elevated in animal and human subjects with hypertension and renal injury. We hypothesized that inflammation contributes to hypertension-induced renal injury by impairing autoregulation and microvascular reactivity to P2X(1) receptor activation. Studies were conducted in vitro using the blood-perfused juxtamedullary nephron preparation. Rats receiving ANG II (60 ng/min) infusion were treated with the anti-inflammatory agent pentosan polysulfate (PPS) for 14 days. The magnitude and progression of hypertension were similar in ANG II and ANG II+PPS-treated rats (169 ± 5 vs. 172 ± 2 mmHg). Afferent arterioles from control rats exhibited normal autoregulatory behavior with diameter decreasing from 18.4 ± 1.6 to 11.4 ± 1.7 μm when perfusion pressure was increased from 70 to 160 mmHg. In contrast, pressure-mediated vasoconstriction was markedly attenuated in ANG II-treated rats, and diameter remained essentially unchanged over the range of perfusion pressures. However, ANG II-treated rats receiving PPS exhibited normal autoregulatory behavior compared with ANG II alone rats. Arteriolar reactivity to ATP and β,γ-methylene ATP was significantly reduced in ANG II hypertensive rats compared with controls. Interestingly, PPS treatment preserved normal reactivity to P2 and P2X(1) receptor agonists despite the persistent hypertension. The maximal vasoconstriction was 79 ± 3 and 81 ± 2% of the control diameter for ATP and β,γ-methylene ATP, respectively, similar to responses in control rats. PPS treatment significantly reduced α-smooth muscle actin staining in afferent arterioles and plasma transforming growth factor-β1 concentration in ANG II-treated rats. In conclusion, PPS normalizes autoregulation without altering ANG II-induced hypertension, suggesting that inflammatory processes reduce P2X(1) receptor reactivity and thereby impair autoregulatory behavior in ANG II hypertensive rats.

  17. Reading and spelling abilities in children with severe speech impairments and cerebral palsy at 6, 9, and 12 years of age in relation to cognitive development: a longitudinal study.

    Science.gov (United States)

    Dahlgren Sandberg, Annika

    2006-08-01

    Development of literacy skills was studied in six children (one male, five females) with severe speech impairments and cerebral palsy (CP). These skills were related to intellectual development, phonological abilities, and short-term memory. Three of the children were diagnosed with dystonia, and three with diplegia. They had no, or severely restricted, independent mobility (Gross Motor Function Classification System Level IV for four children and Level V for two), and severe fine motor problems, including difficulty with pointing. As they had no intelligible speech, the Bliss system was the primary communication mode. Assessments were made at approximately 6, 9, and 12 years of age. The results revealed that the children had difficulties acquiring literacy skills, although intellectual level and phonological ability predicted otherwise. Positive development during the first 3 years was followed by an arrest. A conspicuous decrease in IQ points was also found. Thus, phonological ability does not seem to have the same predictive power for literacy development in children with severe speech impairments and CP as in typically developing children. Further studies are needed to clarify the role of phonological abilities, working memory, and strategies used in literacy acquisition in these children. Such studies might also clarify the importance of articulatory abilities in early literacy acquisition.

  18. Cerebral Vasospasm Pharmacological Treatment: An Update

    OpenAIRE

    Ioannis Siasios; Kapsalaki, Eftychia Z; Fountas, Kostas N

    2013-01-01

    Aneurysmal subarachnoid hemorrhage- (aSAH-) associated vasospasm constitutes a clinicopathological entity, in which reversible vasculopathy, impaired autoregulatory function, and hypovolemia take place, and lead to the reduction of cerebral perfusion and finally ischemia. Cerebral vasospasm begins most often on the third day after the ictal event and reaches the maximum on the 5th–7th postictal days. Several therapeutic modalities have been employed for preventing or reversing cerebral vasosp...

  19. Cerebral energy metabolism during induced mitochondrial dysfunction

    DEFF Research Database (Denmark)

    Nielsen, T H; Bindslev, TT; Pedersen, S M

    2013-01-01

    In patients with traumatic brain injury as well as stroke, impaired cerebral oxidative energy metabolism may be an important factor contributing to the ultimate degree of tissue damage. We hypothesize that mitochondrial dysfunction can be diagnosed bedside by comparing the simultaneous changes in...... in brain tissue oxygen tension (PbtO(2)) and cerebral cytoplasmatic redox state. The study describes cerebral energy metabolism during mitochondrial dysfunction induced by sevoflurane in piglets....

  20. Positive Autoregulation of an Acyl-Homoserine Lactone Quorum-Sensing Circuit Synchronizes the Population Response.

    Science.gov (United States)

    Scholz, Rebecca L; Greenberg, E Peter

    2017-07-25

    Many proteobacteria utilize acyl-homoserine lactone quorum-sensing signals. At low population densities, cells produce a basal level of signal, and when sufficient signal has accumulated in the surrounding environment, it binds to its receptor, and quorum-sensing-dependent genes can be activated. A common characteristic of acyl-homoserine lactone quorum sensing is that signal production is positively autoregulated. We have examined the role of positive signal autoregulation in Pseudomonas aeruginosa We compared population responses and individual cell responses in populations of wild-type P. aeruginosa to responses in a strain with the signal synthase gene controlled by an arabinose-inducible promoter so that signal was produced at a constant rate per cell regardless of cell population density. At a population level, responses of the wild type and the engineered strain were indistinguishable, but the responses of individual cells in a population of the wild type showed greater synchrony than the responses of the engineered strain. Although sufficient signal is required to activate expression of quorum-sensing-regulated genes, it is not sufficient for activation of certain genes, the late genes, and their expression is delayed until other conditions are met. We found that late gene responses were reduced in the engineered strain. We conclude that positive signal autoregulation is not a required element in acyl-homoserine lactone quorum sensing, but it functions to enhance synchrony of the responses of individuals in a population. Synchrony might be advantageous in some situations, whereas a less coordinated quorum-sensing response might allow bet hedging and be advantageous in other situations.IMPORTANCE There are many quorum-sensing systems that involve a transcriptional activator, which responds to an acyl-homoserine lactone signal. In all of the examples studied, the gene coding for signal production is positively autoregulated by the signal, and it has even

  1. A simple model of cerebral blood flow dependence on arterial blood pressure

    CERN Document Server

    Gersten, Alexander

    2011-01-01

    It is shown that the dependence of the cerebral blood flow (CBF) on mean arterial blood pressure (MABP) can be described with a simple model having the following assumptions. Below certain MABP (denoted as MABP1) there are no autoregulatory or feedback mechanisms influencing CBF. Between MABP1 and MABP2 (MABP at which breakthrough accurs) there is a linear (on MABP) dependent feedback with a sloap depending very much on the individual considered. The classical autoregulation model with a plateau in between MABP1 and MABP2 is a particular case of this model. The model describes well the experiments performed on dogs (Harper 1966), for which the individual feedback sloap parameter varied to great extent, indicating the importance of mesurments on individuals against averaged mesurments (or measurments on diffent individuals) which superficially support the classical autoregulation. New effect of decreased CBF, while increasing MABP, was observed.

  2. L-3-n-Butylphthalide Activates Akt/mTOR Signaling, Inhibits Neuronal Apoptosis and Autophagy and Improves Cognitive Impairment in Mice with Repeated Cerebral Ischemia-Reperfusion Injury.

    Science.gov (United States)

    Xu, Jing; Huai, Yaping; Meng, Nan; Dong, Yanhong; Liu, Zhijuan; Qi, Qianqian; Hu, Ming; Fan, Mingyue; Jin, Wei; Lv, Peiyuan

    2017-06-15

    L-3-n-Butylphthalide (L-NBP) exerts neuroprotective effects in animal models of cerebral ischemia, but its potential benefits in repeated cerebral ischemia-reperfusion (RCIR) injury remain unknown. We investigated the effect of L-NBP on cognitive impairment induced by RCIR in mice. Male C57Bl/6 mice received sham surgery or bilateral common carotid artery occlusion (3 times, 20 min each) and were orally administered preoperative L-NBP (30 mg/kg/day, 7 days), postoperative L-NBP (30 or 60 mg/kg/day, 28 days) or postoperative vehicle (28 days). Learning and memory were assessed by the Morris water maze task and step-down passive avoidance test. Nissl staining was used to identify pathologic changes in the hippocampal CA1 region. The expressions of proteins associated with signaling, apoptosis and autophagy were assessed by quantitative PCR and western blot. RCIR induced deficits in learning and memory that were alleviated by preoperative or postoperative L-NBP administration. Pathologic lesions in the hippocampal CA1 region induced by RCIR were less severe in mice treated with L-NBP. Preoperative or postoperative L-NBP administration in mice receiving RCIR promoted hippocampal expression of phospho-Akt and phospho-mTOR (suggesting activation of Akt/mTOR signaling), increased the Bcl-2/Bax ratio (indicating suppression of apoptosis) and reduced the LC3-II/LC3-I ratio (implying inhibition of autophagy). Preoperative or postoperative L-NBP administration also depressed hippocampal levels of beclin-1 mRNA (indicating suppression of autophagy). These findings suggest that the effect of L-NBP to alleviate learning and memory deficits in mice following RCIR may involve activation of Akt/mTOR signaling and regulation of the expressions of proteins related to apoptosis and autophagy.

  3. Nonlinear system analysis of renal autoregulation in normotensive and hypertensive rats

    DEFF Research Database (Denmark)

    Chon, K H; Chen, Y M; Holstein-Rathlou, N H;

    1998-01-01

    We compared the dynamic characteristics in renal autoregulation of blood flow of normotensive Sprague-Dawley rats (SDR) and spontaneously hypertensive rats (SHR), using both linear and nonlinear systems analysis. Linear analysis yielded only limited information about the differences in dynamics...... of nonlinear interactions between the oscillatory components of the myogenic mechanism and tubuloglomerular feedback (TGF) at the level of whole kidney blood flow in SDR. An interaction between these two mechanisms had previously been revealed for SDR only at the single nephron level. However, nonlinear......, NMSE are significantly higher in SHR than SDR, suggesting a more complex nonlinear system in SHR. The contribution of the third-order kernel in describing the dynamics of renal autoregulation in arterial blood pressure and blood flow was found to be important. Moreover, we have identified the presence...

  4. Structural network alterations and neurological dysfunction in cerebral amyloid angiopathy

    NARCIS (Netherlands)

    Reijmer, Yael D.; Fotiadis, Panagiotis; Martinez-Ramirez, Sergi; Salat, David H.; Schultz, Aaron; Shoamanesh, Ashkan; Ayres, Alison M.; Vashkevich, Anastasia; Rosas, Diana; Schwab, Kristin; Leemans, Alexander; Biessels, Geert Jan; Rosand, Jonathan; Johnson, Keith A.; Viswanathan, Anand; Gurol, M. Edip; Greenberg, Steven M.

    2015-01-01

    Cerebral amyloid angiopathy is a common form of small-vessel disease and an important risk factor for cognitive impairment. The mechanisms linking small-vessel disease to cognitive impairment are not well understood. We hypothesized that in patients with cerebral amyloid angiopathy, multiple small s

  5. Disassociation of Static and Dynamic Cerebral Autoregulatory Performance in Healthy Volunteers After Lipopolysaccharide Infusion and in Patients with Sepsis

    DEFF Research Database (Denmark)

    Berg, Ronan Martin Griffin; Plovsing, Ronni R.; Ronit, Andreas

    2012-01-01

    autoregulatory performance after LPS infusion and in patients with sepsis was similar to values in healthy volunteers at baseline. In contrast, TFA showed decreased gain and an increased phase difference between blood pressure and cerebral artery blood flow velocity after LPS (both p ...-experimental model of the systemic inflammatory response during early sepsis, and (ii) in patients with advanced clinical sepsis. Cerebral autoregulation was tested using transcranial Doppler ultrasonography (i) before and after lipopolysaccharide (LPS) infusion in healthy volunteers (n=9), and (ii) in patients......); patients exhibited similar gain but lower phase difference values (p

  6. Interfacing a haptic robotic system with complex virtual environments to treat impaired upper extremity motor function in children with cerebral palsy

    Science.gov (United States)

    FLUET, GERARD G.; QIU, QINYIN; KELLY, DONNA; PARIKH, HETA D.; RAMIREZ, DIEGO; SALEH, SOHA; ADAMOVICH, SERGEI V.

    2011-01-01

    Objective To investigate the ability of the New Jersey Institute of Technology Robot Assisted Virtual Rehabilitation (NJIT-RAVR) system training to elicit changes in upper extremity (UE) function in children with hemiplegia secondary to cerebral palsy. Methods Nine children (mean age 9 years, three males) participated in three pilots. Subjects trained 1 hour, 3 days a week for 3 weeks. Two groups performed this protocol as their only intervention. The third group also performed 5–6 hours of constraint-induced movement therapy. Results All subjects participated in a short programme of nine, 60-minute training sessions without adverse effects. As a group, subjects demonstrated statistically significant improvements in Melbourne Assessment of Unilateral Upper Limb Function Test, a composite of three timed UE tasks and several measurements of reaching kinematics. Several subjects demonstrated clinically significant improvements in active shoulder abduction and flexion as well as forearm supination. Conclusion Three small pilots of NJIT-RAVR training demonstrated measurable benefit with no complications, warranting further examination. PMID:20828330

  7. Alleviation of Motor Impairments in Patients with Cerebral Palsy: Acute Effects of Whole-body Vibration on Stretch Reflex Response, Voluntary Muscle Activation and Mobility.

    Science.gov (United States)

    Krause, Anne; Schönau, Eckhard; Gollhofer, Albert; Duran, Ibrahim; Ferrari-Malik, Anja; Freyler, Kathrin; Ritzmann, Ramona

    2017-01-01

    Individuals suffering from cerebral palsy (CP) often have involuntary, reflex-evoked muscle activity resulting in spastic hyperreflexia. Whole-body vibration (WBV) has been demonstrated to reduce reflex activity in healthy subjects, but evidence in CP patients is still limited. Therefore, this study aimed to establish the acute neuromuscular and kinematic effects of WBV in subjects with spastic CP. 44 children with spastic CP were tested on neuromuscular activation and kinematics before and immediately after a 1-min bout of WBV (16-25 Hz, 1.5-3 mm). Assessment included (1) recordings of stretch reflex (SR) activity of the triceps surae, (2) electromyography (EMG) measurements of maximal voluntary muscle activation of lower limb muscles, and (3) neuromuscular activation during active range of motion (aROM). We recorded EMG of m. soleus (SOL), m. gastrocnemius medialis (GM), m. tibialis anterior, m. vastus medialis, m. rectus femoris, and m. biceps femoris. Angular excursion was recorded by goniometry of the ankle and knee joint. After WBV, (1) SOL SRs were decreased (p control. This facilitation of muscle and joint control is probably due to a reduction of spasticity-associated spinal excitability in favor of giving access for greater supraspinal input during voluntary motor control.

  8. NEYROPSYCHOLOGICAL CONSECUENCES OF CEREBRAL PALSY

    Directory of Open Access Journals (Sweden)

    ANA MARÍA NAVARRO MELENDRO

    2005-01-01

    Full Text Available Cerebral Palsy is defined as a movement alteration result of a non progressive damage witch is permanent in anencephalon that has not acquired its final maturation. Patients that suffer cerebral palsy present learning disabilities,that varies between being completely normal to severe as a consequence of memory, gnosis, praxis, perceptive andlanguage impairments. Nevertheless the consequences of this disease are not always predictable. This paper pretendsto make a description of the cognitive and behavioral deficits that overcomes along with the manifestation of thecerebral palsy and its possible treatment. We used a complete neuropsychological battery to evaluate a 7 years oldpatient who was diagnosed of cerebral palsy and spastic diplegia finding some cognitive impairment in fields such asmnesic, gnosic and attention processes.

  9. Clinical and Physiological Events That Contribute to the Success Rate of Finding "Optimal" Cerebral Perfusion Pressure in Severe Brain Trauma Patients

    NARCIS (Netherlands)

    Weersink, Corien S. A.; Aries, Marcel J. H.; Dias, Celeste; Liu, Mary X.; Kolias, Angelos G.; Donnelly, Joseph; Czosnyka, Marek; van Dijk, J. Marc C.; Regtien, Joost; Menon, David K.; Hutchinson, Peter J.; Smielewski, Peter

    2015-01-01

    Objective: Recently, a concept of an individually targeted level of cerebral perfusion pressure that aims to restore impaired cerebral vasoreactivity has been advocated after traumatic brain injury. The relationship between cerebral perfusion pressure and pressure reactivity index normally is suppos

  10. Alleviation of Motor Impairments in Patients with Cerebral Palsy: Acute Effects of Whole-body Vibration on Stretch Reflex Response, Voluntary Muscle Activation and Mobility

    Directory of Open Access Journals (Sweden)

    Anne Krause

    2017-08-01

    Full Text Available IntroductionIndividuals suffering from cerebral palsy (CP often have involuntary, reflex-evoked muscle activity resulting in spastic hyperreflexia. Whole-body vibration (WBV has been demonstrated to reduce reflex activity in healthy subjects, but evidence in CP patients is still limited. Therefore, this study aimed to establish the acute neuromuscular and kinematic effects of WBV in subjects with spastic CP.Methods44 children with spastic CP were tested on neuromuscular activation and kinematics before and immediately after a 1-min bout of WBV (16–25 Hz, 1.5–3 mm. Assessment included (1 recordings of stretch reflex (SR activity of the triceps surae, (2 electromyography (EMG measurements of maximal voluntary muscle activation of lower limb muscles, and (3 neuromuscular activation during active range of motion (aROM. We recorded EMG of m. soleus (SOL, m. gastrocnemius medialis (GM, m. tibialis anterior, m. vastus medialis, m. rectus femoris, and m. biceps femoris. Angular excursion was recorded by goniometry of the ankle and knee joint.ResultsAfter WBV, (1 SOL SRs were decreased (p < 0.01 while (2 maximal voluntary activation (p < 0.05 and (3 angular excursion in the knee joint (p < 0.01 were significantly increased. No changes could be observed for GM SR amplitudes or ankle joint excursion. Neuromuscular coordination expressed by greater agonist–antagonist ratios during aROM was significantly enhanced (p < 0.05.DiscussionThe findings point toward acute neuromuscular and kinematic effects following one bout of WBV. Protocols demonstrate that pathological reflex responses are reduced (spinal level, while the execution of voluntary movement (supraspinal level is improved in regards to kinematic and neuromuscular control. This facilitation of muscle and joint control is probably due to a reduction of spasticity-associated spinal excitability in favor of giving access for greater supraspinal input during voluntary motor

  11. Decreased cerebral {alpha}4{beta}2* nicotinic acetylcholine receptor availability in patients with mild cognitive impairment and Alzheimer's disease assessed with positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kendziorra, Kai; Meyer, Philipp Mael; Barthel, Henryk; Hesse, Swen; Becker, Georg Alexander; Luthardt, Julia; Schildan, Andreas; Patt, Marianne; Sorger, Dietlind; Seese, Anita; Sabri, Osama [University of Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Wolf, Henrike [University of Leipzig, Department of Psychiatry, Leipzig (Germany); University of Zurich, Department of Old Age Psychiatry and Psychiatry Research, Psychiatric University Hospital (PUK) Zurich, Zurich (Switzerland); Gertz, Herman-Josef [University of Leipzig, Department of Psychiatry, Leipzig (Germany)

    2011-03-15

    Postmortem studies indicate a loss of nicotinic acetylcholine receptor (nAChRs) in Alzheimer's disease (AD). In order to establish whether these changes in the cholinergic system occur at an early stage of AD, we carried out positron emission tomography (PET) with a specific radioligand for the {alpha}4{beta}2* nicotinic acetylcholine receptor ({alpha}4{beta}2* nAChR) in patients with mild to moderate AD and in patients with amnestic mild cognitive impairment (MCI), who have a high risk to progress to AD. Nine patients with moderate AD, eight patients with MCI and seven age-matched healthy controls underwent 2-[{sup 18}F]fluoro-3-(2(S)-azetidinylmethoxy)pyridine (2-[{sup 18}F]FA-85380) PET. After coregistration with individual magnetic resonance imaging the binding potential (BP{sub ND}) of 2-[{sup 18}F]FA-85380 was calculated using either the corpus callosum or the cerebellum as reference regions. PET data were analysed by region of interest analysis and by voxel-based analysis. Both patients with AD and MCI showed a significant reduction in 2-[{sup 18}F]FA-85380 BP{sub ND} in typical AD-affected brain regions. Thereby, the corpus callosum was identified as the most suitable reference region. The 2-[{sup 18}F]FA-85380 BP{sub ND} correlated with the severity of cognitive impairment. Only MCI patients that converted to AD in the later course (n = 5) had a reduction in 2-[{sup 18}F]FA-85380 BP{sub ND}. 2-[{sup 18}F]FA-85380 PET appears to be a sensitive and feasible tool for the detection of a reduction in {alpha}4{beta}2* nAChRs which seems to be an early event in AD. In addition, 2-[{sup 18}F]FA-85380 PET might give prognostic information about a conversion from MCI to AD. (orig.)

  12. Vasoespasmo cerebral

    Directory of Open Access Journals (Sweden)

    Antonio A. F. de Salles

    1987-09-01

    Full Text Available Vasoespasmo cerebral ocorre em patologias como enxaqueca, hemorragia subaracnóidea, trauma de crânio, após isquemia e/ou hipoxia. A fisiopatologia do vasoespasmo cerebral nestas patologias não está completamente desvendada. Neste artigo são analisados os fatores neuroquímicos e morfológicos responsáveis pelo controle circulatório cerebral. As alterações circulatórias que seguem a hemorragia subaracnóidea são utilizadas como exemplo. Conclui-se que fatores bioquímicos, fisiológicos e morfológicos são responsáveis pelas manifestações vasculares que ocorrem após a hemorragia subaracnóidea. Alternativas de tratamento do vasoespasmo cerebral são discutidas.

  13. Gait Stability in Children with Cerebral Palsy

    Science.gov (United States)

    Bruijn, Sjoerd M.; Millard, Matthew; van Gestel, Leen; Meyns, Pieter; Jonkers, Ilse; Desloovere, Kaat

    2013-01-01

    Children with unilateral Cerebral Palsy (CP) have several gait impairments, amongst which impaired gait stability may be one. We tested whether a newly developed stability measure (the foot placement estimator, FPE) which does not require long data series, can be used to asses gait stability in typically developing (TD) children as well as…

  14. Gait Stability in Children with Cerebral Palsy

    Science.gov (United States)

    Bruijn, Sjoerd M.; Millard, Matthew; van Gestel, Leen; Meyns, Pieter; Jonkers, Ilse; Desloovere, Kaat

    2013-01-01

    Children with unilateral Cerebral Palsy (CP) have several gait impairments, amongst which impaired gait stability may be one. We tested whether a newly developed stability measure (the foot placement estimator, FPE) which does not require long data series, can be used to asses gait stability in typically developing (TD) children as well as…

  15. Cerebral Paragonimiasis.

    Science.gov (United States)

    Miyazaki, I

    1975-01-01

    The first case of cerebral paragonimiasis was reported by Otani in Japan in 1887. This was nine years after Kerbert's discovery of the fluke in the lungs of Bengal tigers and seven years after a human pulmonary infection by the fluke was demonstrated by Baelz and Manson. The first case was a 26-year-old man who had been suffering from cough and hemosputum for one year. The patient developed convulsive seizures with subsequent coma and died. The postmortem examination showed cystic lesions in the right frontal and occipital lobes. An adult fluke was found in the occipital lesion and another was seen in a gross specimen of normal brain tissue around the affected occipital lobe. Two years after Otani's discovery, at autopsy a 29-year-old man with a history of Jacksonian seizure was reported as having cerebral paragonimiasis. Some time later, however, it was confirmed that the case was actually cerebral schistosomiasis japonica. Subsequently, cases of cerebral paragonimiasis were reported. However, the majority of these cases were not confirmed histologically. It was pointed out that some of these early cases were probably not Paragonimus infection. After World War II, reviews as well as case reports were published. Recently, investigations have been reported from Korea, with a clinicla study on 62 cases of cerebral paragonimiasis seen at the Neurology Department of the National Medical Center, Seoul, between 1958 and 1964. In 1971 Higashi described a statistical study on 105 cases of cerebral paragonimiasis that had been treated surgically in Japan.

  16. Cerebral PET glucose hypometabolism in subjects with mild cognitive impairment and higher EEG high-alpha/low-alpha frequency power ratio.

    Science.gov (United States)

    Moretti, Davide Vito; Pievani, Michela; Pini, Lorenzo; Guerra, Ugo Paolo; Paghera, Barbara; Frisoni, Giovanni Battista

    2017-10-01

    In Alzheimer's disease (AD) research, both 2-deoxy-2-((18)F)fluoro-D-glucose (FDG) positron emission tomography (PET) and electroencephalography (EEG) are reliable investigational modalities. The aim of this study was to investigate the associations between EEG High-alpha/Low-alpha (H-alpha/L-alpha) power ratio and cortical glucose metabolism. A total of 23 subjects with mild cognitive impairment (MCI) underwent FDG-PET and EEG examinations. H-alpha/L-alpha power ratio was computed for each subject and 2 groups were obtained based on the increase of the power ratio. The subjects with higher H-alpha/L-alpha power ratio showed a decrease in glucose metabolism in the hub brain areas previously identified as typically affected by AD pathology. In subjects with higher H-alpha/L-alpha ratio and lower metabolism, a "double alpha peak" was identified in the EEG spectrum and a U-shaped correlation between glucose metabolism and increase of H-alpha/L-alpha power ratio has been found. Moreover, in this group, a conversion rate of 62.5% at 24 months was detected, significantly different from the chance percentage expected. The neurophysiological meaning of the interplay between alpha oscillations and glucose metabolism and the possible interest of the H-alpha/L-alpha power ratio as a clinical biomarker in AD have been discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Cerebral white matter fractional anisotropy and tract volume as measured by MR imaging are associated with impaired cognitive and motor function in pediatric posterior fossa tumor survivors.

    Science.gov (United States)

    Rueckriegel, Stefan M; Bruhn, Harald; Thomale, Ulrich W; Hernáiz Driever, Pablo

    2015-07-01

    Disease and therapy cause brain damage and subsequent functional loss in pediatric patients with posterior fossa tumors. Treatment-related toxicity factors are resection in patients with pilocytic astrocytoma (PA) and, additionally, cranio-spinal irradiation together with chemotherapy in patients with medulloblastoma (MB). We tested whether damage to white matter (WM) as revealed by diffusion tensor MR imaging (DTI) correlated with specific cognitive and motor impairments in survivors of pediatric posterior fossa tumors. Eighteen MB (mean age ± SD, 15.2 ± 4.9 y) and 14 PA (12.6 ± 5.0 y) survivors were investigated with DTI on a 3-Tesla-MR system. We identified fractional anisotropy (FA) of WM, the volume ratio of WM to gray matter and cerebrospinal fluid (WM/GM + CSF), and volume of specific frontocerebellar tracts. Ataxia was assessed using the International Cooperative Ataxia Rating Scale (ICARS), while the Wechsler Intelligence Scale for Children determined full-scale intelligence quotients (FSIQ). Amsterdam Neuropsychological Tasks (ANT) was used to assess processing speed. Handwriting automation was analyzed using a digitizing graphic tablet. The WM/GM + CSF ratio correlated significantly with cognitive measures (IQ, P = 0.002; ANT baseline speed, P = 0.04; ANT shifting attention, P = 0.004). FA of skeletonized tracts correlated significantly with FSIQ (P = 0.008), ANT baseline speed (P = 0.028) and ANT shifting attention (P = 0.045). Moreover, frontocerebellar tract volumes correlated with both the FSIQ (P = 0.011) and ICARS (P = 0.007). DTI provides a method for quantification of WM damage by tumor and by therapy-associated effects in survivors of pediatric posterior fossa tumors. DTI-derived WM integrity may be a representative marker for cognitive and motor deterioration. © 2015 Wiley Periodicals, Inc.

  18. Cerebral Palsy (For Teens)

    Science.gov (United States)

    ... Right Sport for You Healthy School Lunch Planner Cerebral Palsy KidsHealth > For Teens > Cerebral Palsy Print A A ... do just what everyone else does. What Is Cerebral Palsy? Cerebral palsy (CP) is a disorder of the ...

  19. Negative autoregulation by Fas stabilizes adult erythropoiesis and accelerates its stress response.

    Directory of Open Access Journals (Sweden)

    Miroslav Koulnis

    Full Text Available Erythropoiesis maintains a stable hematocrit and tissue oxygenation in the basal state, while mounting a stress response that accelerates red cell production in anemia, blood loss or high altitude. Thus, tissue hypoxia increases secretion of the hormone erythropoietin (Epo, stimulating an increase in erythroid progenitors and erythropoietic rate. Several cell divisions must elapse, however, before Epo-responsive progenitors mature into red cells. This inherent delay is expected to reduce the stability of erythropoiesis and to slow its response to stress. Here we identify a mechanism that helps to offset these effects. We recently showed that splenic early erythroblasts, 'EryA', negatively regulate their own survival by co-expressing the death receptor Fas, and its ligand, FasL. Here we studied mice mutant for either Fas or FasL, bred onto an immune-deficient background, in order to avoid an autoimmune syndrome associated with Fas deficiency. Mutant mice had a higher hematocrit, lower serum Epo, and an increased number of splenic erythroid progenitors, suggesting that Fas negatively regulates erythropoiesis at the level of the whole animal. In addition, Fas-mediated autoregulation stabilizes the size of the splenic early erythroblast pool, since mutant mice had a significantly more variable EryA pool than matched control mice. Unexpectedly, in spite of the loss of a negative regulator, the expansion of EryA and ProE progenitors in response to high Epo in vivo, as well as the increase in erythropoietic rate in mice injected with Epo or placed in a hypoxic environment, lagged significantly in the mutant mice. This suggests that Fas-mediated autoregulation accelerates the erythropoietic response to stress. Therefore, Fas-mediated negative autoregulation within splenic erythropoietic tissue optimizes key dynamic features in the operation of the erythropoietic network as a whole, helping to maintain erythroid homeostasis in the basal state, while

  20. Effects of Naokang II on Patients with Vascular Cognitive Impairment after Cerebral Infarction%脑康Ⅱ号对脑梗死后血管性认知障碍患者的干预研究

    Institute of Scientific and Technical Information of China (English)

    王宁群; 黄小波; 魏翠柏; 陈文强; 陈玉静

    2014-01-01

    目的:观察脑康Ⅱ号对脑梗死后无痴呆型血管性认知障碍的临床疗效。方法:将100例符合入组标准的患者随机分为治疗组(中西医结合治疗组)和对照组(西医治疗组)。观察治疗前后患者认知功能、神经功能缺损程度评分、日常生活活动能力及生存质量评分。结果:治疗组NIHSS评分的改善优于对照组(P<0.05);治疗组MoCA评分的改善优于对照组,主要表现在视空间和执行功能、注意力、计算力、延迟回忆、定向力等方面(P<0.05)。治疗组与对照组在特异性生存质量量表“卒中影响量表( SIS)”中体力、日常活动能力、行动能力、社会参与等维度的改善方面具有显著差异,治疗组优于对照组(P<0.05,P<0.01)。结论:脑康Ⅱ号能够改善脑梗死后无痴呆型血管性认知障碍患者的认知功能和生存质量。%Objective:To observe the clinical effect of Naokang II on vascular cognitive impairment without dementia after cerebral infarction.Methods:100 patients that met the inclusion criteria were randomly divided into a treatment group ( treated by combination of Chinese medicine and western medicine ) and a control group ( treated by western medi-cine) .The scores of cognitive function, the neurological function defect, the activities of daily living and life quality were observed before and after treatment.Results: The improvement of NIHSS score in the treatment group was better than that in the control group (P<0.05).The improvement of MoCA score in the treatment group was also better,espe-cially in visual spatial and executive function, attention, calculation, delayed recall and directional function ( P <0.05 ) .The treatment group and the control group showed significant differences in the improvement of physical strength, ability of daily activities, action ability, social participation and other dimensions in the specific quality of life

  1. Regional cerebral blood flow alterations remote from the site of intracranial tumors

    DEFF Research Database (Denmark)

    Endo, H; Larsen, B; Lassen, N A

    1977-01-01

    Regional cerebral blood flow (rCBF) was investigated in 12 patients with brain tumors, using a 254-channel dynamic gamma camera. In nine of the 12 cases, hyperemic regions with loss of autoregulation were seen in sites remote from the tumor (the area around the tumor was in most cases also...... hyperemic). These remote rCBF abnormalities were found in the lower posterior part of the hemisphere in six cases, and in the frontal region in three. The location of the remote rCBF abnormality seemed to depend on the site of the tumor: cases with frontal and posterior fossa mass lesions had hyperemia...

  2. Diagnosis, treatment, and prevention of cerebral palsy.

    Science.gov (United States)

    O'Shea, Thomas Michael

    2008-12-01

    Cerebral palsy is the most prevalent cause of persisting motor function impairment with a frequency of about 1/500 births. In developed countries, the prevalence rose after introduction of neonatal intensive care, but in the past decade, this trend has reversed. A recent international workshop defined cerebral palsy as "a group of permanent disorders of the development of movement and posture, causing activity limitation, that are attributed to non-progressive disturbances that occurred in the developing fetal or infant brain." In a majority of cases, the predominant motor abnormality is spasticity; other forms of cerebral palsy include dyskinetic (dystonia or choreo-athetosis) and ataxic cerebral palsy. In preterm infants, about one-half of the cases have neuroimaging abnormalities, such as echolucency in the periventricular white matter or ventricular enlargement on cranial ultrasound. Among children born at or near term, about two-thirds have neuroimaging abnormalities, including focal infarction, brain malformations, and periventricular leukomalacia. In addition to the motor impairment, individuals with cerebral palsy may have sensory impairments, cognitive impairment, and epilepsy. Ambulation status, intelligence quotient, quality of speech, and hand function together are predictive of employment status. Mortality risk increases incrementally with increasing number of impairments, including intellectual, limb function, hearing, and vision. The care of individuals with cerebral palsy should include the provision of a primary care medical home for care coordination and support; diagnostic evaluations to identify brain abnormalities, severity of neurologic and functional abnormalities, and associated impairments; management of spasticity; and care for associated problems such as nutritional deficiencies, pain, dental care, bowel and bladder continence, and orthopedic complications. Current strategies to decrease the risk of cerebral palsy include interventions to

  3. 白花前胡合剂对脑缺血再灌注大鼠神经功能缺损的影响%Effect of Baihuaqianhu Mixture on Infraction Impairment of Rats with Cerebral Ischemia Reperfusion

    Institute of Scientific and Technical Information of China (English)

    周小莉; 董梦久

    2011-01-01

    Objective: To investigate the improvement degree of the Baihuaqianhu Mixture on neurological impairment. Methods: These rats of middle cerebral artery occlusion models that were established by the suture method were divided randomly into the sham-operation group, the model group, the low dose of Baihuaqianhu Mixture group, the middle dose of Baihuaqianhu Mixture group and the large dose of Baihuaqianhu Mixture group. After conscious, these models were given the corresponding medicine. Indices were detected in the 3rd day. Results: Compared with the model group, infraction areas of these Baihuaqianhu Mixture groups were induced significantly. The difference of the large dose of Baihuaqianhu Mixture group was the most obvious. In these symptoms of the neurological impairment, there were some statistical differences among these Baihuaqianhu Mixture groups and the model group. Conclusion: The Baihuaqianhu Mixtrue has the effect of reducing the infraction size.%目的 探讨白花前胡合剂对造模后大鼠神经功能缺损的改善程度.方法 采用线栓法制作大鼠大脑中动脉脑缺血再灌注模型,设立假手术组、模型组、白花前胡合剂大、中、小剂量治疗组,造模动物清醒后即刻给药,于第3日观察各项指标.结果 各剂量治疗组与模型组相比梗死面积显著缩小,以大剂量组最明显;各剂量治疗组动物神经功能缺损症状也有不同程度改善,与模型组相比有显著差异.结论 提示白花前胡合剂具有减少梗死面积的作用.

  4. Vasoespasmo cerebral

    OpenAIRE

    1987-01-01

    Vasoespasmo cerebral ocorre em patologias como enxaqueca, hemorragia subaracnóidea, trauma de crânio, após isquemia e/ou hipoxia. A fisiopatologia do vasoespasmo cerebral nestas patologias não está completamente desvendada. Neste artigo são analisados os fatores neuroquímicos e morfológicos responsáveis pelo controle circulatório cerebral. As alterações circulatórias que seguem a hemorragia subaracnóidea são utilizadas como exemplo. Conclui-se que fatores bioquímicos, fisiológicos e morfológi...

  5. Resting cerebral blood flow

    Science.gov (United States)

    Ances, B M.; Sisti, D; Vaida, F; Liang, C L.; Leontiev, O; Perthen, J E.; Buxton, R B.; Benson, D; Smith, D M.; Little, S J.; Richman, D D.; Moore, D J.; Ellis, R J.

    2009-01-01

    Objective: HIV enters the brain soon after infection causing neuronal damage and microglial/astrocyte dysfunction leading to neuropsychological impairment. We examined the impact of HIV on resting cerebral blood flow (rCBF) within the lenticular nuclei (LN) and visual cortex (VC). Methods: This cross-sectional study used arterial spin labeling MRI (ASL-MRI) to measure rCBF within 33 HIV+ and 26 HIV− subjects. Nonparametric Wilcoxon rank sum test assessed rCBF differences due to HIV serostatus. Classification and regression tree (CART) analysis determined optimal rCBF cutoffs for differentiating HIV serostatus. The effects of neuropsychological impairment and infection duration on rCBF were evaluated. Results: rCBF within the LN and VC were significantly reduced for HIV+ compared to HIV− subjects. A 2-tiered CART approach using either LN rCBF ≤50.09 mL/100 mL/min or LN rCBF >50.09 mL/100 mL/min but VC rCBF ≤37.05 mL/100 mL/min yielded an 88% (29/33) sensitivity and an 88% (23/26) specificity for differentiating by HIV serostatus. HIV+ subjects, including neuropsychologically unimpaired, had reduced rCBF within the LN (p = 0.02) and VC (p = 0.001) compared to HIV− controls. A temporal progression of brain involvement occurred with LN rCBF significantly reduced for both acute/early (<1 year of seroconversion) and chronic HIV-infected subjects, whereas rCBF in the VC was diminished for only chronic HIV-infected subjects. Conclusion: Resting cerebral blood flow (rCBF) using arterial spin labeling MRI has the potential to be a noninvasive neuroimaging biomarker for assessing HIV in the brain. rCBF reductions that occur soon after seroconversion possibly reflect neuronal or vascular injury among HIV+ individuals not yet expressing neuropsychological impairment. GLOSSARY AEH = acute/early HIV infection; ANOVA = analysis of variance; ASL-MRI = arterial spin labeling MRI; CART = classification and regression tree; CBF = cerebral blood flow; CH = chronic HIV

  6. Cerebral infarction in patient with minimal change nephrotic syndrome.

    Science.gov (United States)

    Babu, A; Boddana, P; Robson, S; Ludeman, L

    2013-01-01

    We report a case of 68-year-old Caucasian man who presented with cerebral infarcts secondary to arterial thrombosis associated with nephrotic syndrome. His initial presentation included edema of legs, left hemiparesis, and right-sided cerebellar signs. Investigations with computed tomography and magnetic resonance imaging of brain showed multiple cerebral infarcts in middle cerebral and posterior cerebral artery territory. Blood and urine investigations also showed impaired renal function, hypercholesterolemia, hypoalbuminaemia, and nephrotic range proteinuria. Renal biopsy showed minimal change disease. Cerebral infarcts were treated with antiplatelet agents and nephrotic syndrome was treated with high dose steroids. Patient responded well to the treatment and is all well till date.

  7. CRP-dependent positive autoregulation and proteolytic degradation regulate competence activator Sxy of Escherichia coli.

    Science.gov (United States)

    Jaskólska, Milena; Gerdes, Kenn

    2015-03-01

    Natural competence, the ability of bacteria to take up exogenous DNA and incorporate it into their chromosomes, is in most bacteria a transient phenomenon under complex genetic and environmental control. In the Gram-negative bacteria Haemophilus influenzae and Vibrio cholerae, the master regulator Sxy/TfoX controls competence development. Although not known to be naturally competent, Escherichia coli possesses a Sxy homologue and a competence regulon containing the genes required for DNA uptake. Here, we show that in contrast to other characterised Gamma-proteobacteria, E. coli Sxy is positively autoregulated at the level of transcription by a mechanism that requires cAMP receptor protein (CRP), cyclic AMP (cAMP) and a CRP-S site in the sxy promoter. Similarly, we found no evidence that Sxy expression in E. coli was regulated at the translational level. However, our analysis revealed that Sxy is an unstable protein and that its cellular level is negatively regulated at the post-translational level via degradation by Lon protease. Interestingly, in the Gram-positive model organism Bacillus subtilis, the competence master regulator ComK is also positively autoregulated at the level of transcription and negatively regulated by proteolysis. Together, these findings reveal striking similarities between the competence regulons of a Gram-positive and a Gram-negative bacterium.

  8. Evolutionary conservation of Nkx2.5 autoregulation in the second heart field.

    Science.gov (United States)

    Clark, Christopher D; Zhang, Boding; Lee, Benjamin; Evans, Samuel I; Lassar, Andrew B; Lee, Kyu-Ho

    2013-02-01

    The cardiac homeobox gene Nkx2.5 plays a key and dosage-sensitive role in the differentiation of outflow tract and right ventricle from progenitors of the second heart field (SHF) and Nkx2.5 mutation is strongly associated with human outflow tract congenital heart disease (OFT CHD). Therefore defining the regulatory mechanisms controlling Nkx2.5 expression in SHF populations serves an important function in understanding the etiology of complex CHD. Through a comparative analysis of regulatory elements controlling SHF expression of Nkx2.5 in the chicken and mouse, we have found evidence that Nkx2.5 autoregulation is important for maintaining Nkx2.5 expression during SHF differentiation in both species. However the mechanism of Nkx2.5 maintenance differs between placental mammals and non-mammalian vertebrates: in chick Nkx2.5 binds directly to a genomic enhancer element that is required to maintain Nkx2.5 expression in the SHF. In addition, it is likely that this is true in other non-mammalian vertebrates given that they possess a similar genomic organization. By contrast, in placental mammals, Nkx2.5 autoregulation in the SHF functions indirectly through Mef2c. These data underscore a tight relationship in mammals between Nkx2.5 and Mef2c in SHF transcriptional regulation, and highlight the potential for evolutionary cis-regulatory analysis to identify core, conserved components of the gene networks controlling heart development.

  9. Positive autoregulation shapes response timing and intensity in two-component signal transduction systems.

    Science.gov (United States)

    Mitrophanov, Alexander Y; Hadley, Tricia J; Groisman, Eduardo A

    2010-08-27

    Positive feedback loops are regulatory elements that can modulate expression output, kinetics and noise in genetic circuits. Transcriptional regulators participating in such loops are often expressed from two promoters, one constitutive and one autoregulated. Here, we investigate the interplay of promoter strengths and the intensity of the stimulus activating the transcriptional regulator in defining the output of a positively autoregulated genetic circuit. Using a mathematical model of two-component regulatory systems, which are present in all domains of life, we establish that positive feedback strongly affects the steady-state output levels at both low and high levels of stimulus if the constitutive promoter of the regulator is weak. By contrast, the effect of positive feedback is negligible when the constitutive promoter is sufficiently strong, unless the stimulus intensity is very high. Furthermore, we determine that positive feedback can affect both transient and steady state output levels even in the simplest genetic regulatory systems. We tested our modeling predictions by abolishing the positive feedback loop in the two-component regulatory system PhoP/PhoQ of Salmonella enterica, which resulted in diminished induction of PhoP-activated genes. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  10. Changes in cortisol level in saliva following relaxation-activation autoregulative intervention.

    Science.gov (United States)

    Machac, M; Machacová, H; Stárka, L; Hampl, R

    1987-09-01

    The relaxation-activation autoregulative method (RAM) is a psychoregulative procedure characterized by typical autonomic patterns of relaxation and activation phases (blood pressure, electric skin resistance, heart beat, EEG, etc.). They are used as feedback information in the training of autoregulative abilities. RAM has a multidimensional (non-specific) tuning effect which is manifested by changes in the psychophysiological state (emotional tuning, physiological functioning and performance). It has a therapeutical effect on disorders with a psychic pathogenic component, e.g., essential hypertension. The increased production of adrenaline following the application of RAM was found in previous experiments.--The present experiment with a sample of six persons well mastering RAM has shown that the cortisol level following this psychoregulative intervention also rises significantly and that this rise has been recorded over three days, i.e., over the whole period of saliva sampling. It may be said that RAM has a non-specific, ergotropic (activating) subsequent effect and that this effect has the character of stress, more accurately eustress. Autogenic training, on the other hand, reduces the cortisol level.

  11. Negative and positive auto-regulation of BMP expression in early eye development.

    Science.gov (United States)

    Huang, Jie; Liu, Ying; Filas, Benjamen; Gunhaga, Lena; Beebe, David C

    2015-11-15

    Previous results have shown that Bone Morphogenetic Protein (BMP) signaling is essential for lens specification and differentiation. How BMP signals are regulated in the prospective lens ectoderm is not well defined. To address this issue we have modulated BMP activity in a chicken embryo pre-lens ectoderm explant assay, and also studied transgenic mice, in which the type I BMP receptors, Bmpr1a and Acvr1, are deleted from the prospective lens ectoderm. Our results show that chicken embryo pre-lens ectoderm cells express BMPs and require BMP signaling for lens specification in vitro, and that in vivo inhibition of BMP signals in the mouse prospective lens ectoderm interrupts lens placode formation and prevents lens invagination. Furthermore, our results provide evidence that BMP expression is negatively auto-regulated in the lens-forming ectoderm, decreasing when the tissue is exposed to exogenous BMPs and increasing when BMP signaling is prevented. In addition, eyes lacking BMP receptors in the prospective lens placode develop coloboma in the adjacent wild type optic cup. In these eyes, Bmp7 expression increases in the ventral optic cup and the normal dorsal-ventral gradient of BMP signaling in the optic cup is disrupted. Pax2 becomes undetectable and expression of Sfrp2 increases in the ventral optic cup, suggesting that increased BMP signaling alter their expression, resulting in failure to close the optic fissure. In summary, our results suggest that negative and positive auto-regulation of BMP expression is important to regulate early eye development.

  12. No apparent role for T-type Ca2+ channels in renal autoregulation

    DEFF Research Database (Denmark)

    Frandsen, Rasmus Hassing; Salomonsson, Max; Hansen, Pernille B. Lærkegaard

    2016-01-01

    elucidated due to lack of selective pharmacological inhibitors. The role of T- and L-type calcium channels in the response to acute increases in RPP in T-type channel knockout mice (CaV3.1) and normo- and hypertensive rats was examined. Changes in afferent arteriolar diameter in the kidneys from wild......-type and CaV3.1 knockout mice were assessed. Autoregulation of renal blood flow was examined during acute increases in RPP in normo- and hypertensive rats under pharmacological blockade of T- and L-type calcium channels using mibefradil (0.1 μM) and nifedipine (1 μM). In contrast to the results from previous...... pharmacological studies, genetic deletion of T-type channels CaV3.1 did not affect renal autoregulation. Pharmacological blockade of T-type channels using concentrations of mibefradil which specifically blocks T-type channels also had no effect in wild-type or knockout mice. Blockade of L-type channels...

  13. Increased cytoplasmic TARDBP mRNA in affected spinal motor neurons in ALS caused by abnormal autoregulation of TDP-43

    Science.gov (United States)

    Koyama, Akihide; Sugai, Akihiro; Kato, Taisuke; Ishihara, Tomohiko; Shiga, Atsushi; Toyoshima, Yasuko; Koyama, Misaki; Konno, Takuya; Hirokawa, Sachiko; Yokoseki, Akio; Nishizawa, Masatoyo; Kakita, Akiyoshi; Takahashi, Hitoshi; Onodera, Osamu

    2016-01-01

    Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disorder. In motor neurons of ALS, TAR DNA binding protein-43 (TDP-43), a nuclear protein encoded by TARDBP, is absent from the nucleus and forms cytoplasmic inclusions. TDP-43 auto-regulates the amount by regulating the TARDBP mRNA, which has three polyadenylation signals (PASs) and three additional alternative introns within the last exon. However, it is still unclear how the autoregulatory mechanism works and how the status of autoregulation in ALS motor neurons without nuclear TDP-43 is. Here we show that TDP-43 inhibits the selection of the most proximal PAS and induces splicing of multiple alternative introns in TARDBP mRNA to decrease the amount of cytoplasmic TARDBP mRNA by nonsense-mediated mRNA decay. When TDP-43 is depleted, the TARDBP mRNA uses the most proximal PAS and is increased in the cytoplasm. Finally, we have demonstrated that in ALS motor neurons—especially neurons with mislocalized TDP-43—the amount of TARDBP mRNA is increased in the cytoplasm. Our observations indicate that nuclear TDP-43 contributes to the autoregulation and suggests that the absence of nuclear TDP-43 induces an abnormal autoregulation and increases the amount of TARDBP mRNA. The vicious cycle might accelerate the disease progression of ALS. PMID:27257061

  14. Dynamic cerebral autoregulation is unrelated to decrease in external carotid artery blood flow during acute hypotension in healthy young men

    DEFF Research Database (Denmark)

    Ogoh, Shigehiko; Sørensen, Henrik; Hirasawa, Ai

    2016-01-01

    men. Both ICA (mean ± SD; by 17 ± 8%, P = 0.005) and ECA (by 37 ± 15%, P 5 s) than for the ECA blood flow (17 ± 5 s; P = 0.019). The ICA blood flow recovery...... from hypoperfusion was delayed with prazosin (17 ± 4 s versus control 9 ± 5 s, P = 0.006), whereas ECA recovery remained unchanged (P = 0.313) despite a similar reduction in mean arterial pressure (−20 ± 4 mmHg versus control −23 ± 7 mmHg, P = 0.148). These findings suggest that α1-receptor blockade...

  15. Effects of sevoflurane with and without nitrous oxide on human cerebral circulation. Transcranial Doppler study.

    Science.gov (United States)

    Cho, S; Fujigaki, T; Uchiyama, Y; Fukusaki, M; Shibata, O; Sumikawa, K

    1996-10-01

    This study was designed to evaluate the effects of sevoflurane with and without nitrous oxide on human middle cerebral artery (MCA) flow velocity, cerebrovascular carbon dioxide reactivity, and autoregulation compared with the awake state using transcranial Doppler ultrasonography. In 14 patients, the time-mean middle cerebral artery flow velocity (Vmca) was measured when the end-tidal carbon dioxide level was approximately 30, 40, and 50 mmHg under the following conditions: (1) awake; (2) with 2% (1.2 MAC) sevoflurane; and (3) with 1.2 MAC sevoflurane-60% nitrous oxide. In six other patients, the cerebrovascular autoregulation during anesthesia was determined using intravenous phenylephrine to increase blood pressure. Sevoflurane (1.2 MAC) significantly decreased Vmca compared with the awake value at each level of end-tidal carbon dioxide, whereas 1.2 MAC sevoflurane-60% nitrous oxide did not exert significant influence. The Vmca in normocapnic patients decreased from 69 cm/s to 55 cm/s with 1.2 MAC sevoflurane and then increased to 70 cm/s when nitrous oxide was added. Sevoflurane (1.2 MAC) with and without 60% nitrous oxide had a negligible effect on cerebrovascular carbon dioxide reactivity. A phenylephrine-induced increase of mean arterial pressure did not influence Vmca during anesthesia. Sevoflurane (1.2 MAC) reduced Vmca compared with the awake condition, whereas the addition of nitrous oxide caused Vmca to increase toward the values obtained in the awake condition. The cerebrovascular carbon dioxide reactivity and autoregulation were well maintained during 1.2 MAC sevoflurane with and without 60% nitrous oxide.

  16. 基底动脉狭窄与认知功能改变的临床分析%Relation between basilar artery stenosis and cognitive impairment

    Institute of Scientific and Technical Information of China (English)

    李慧英; 黄一宁; 叶长青; 白静

    2012-01-01

    Objective To study the relation between autoregulation of bilateral posterior cerebral artery flow and cognitive function in patients with basilar artery stenosis. Methods Fifteen patients with basilar artery stenosis were divided into stenosis group without cerebral infaction(n = 9) and stenosis group with cerebral infaction(n = 6). Ten healthy volunteers served as a control group. Autoregulation of bilateral posterior cerebral artery flow was assessed by transcranial Doppler ultrasound breath holding test and oblique test. Executive function,structural skill,auditory, visual and logical memory, information processing speed and visuospatial ability were assayed according to the overall neurophysiolgy test and Montreal cognitive assessment(MCA). Results The information processing speed and visuospatial ability were significantly lower in stenosis group with cerebral infarction than in control group(P<0. 05). The visuospatial ability was significantly higher in stenosis group with cerebral infarction than in stenosis group without cerebral infarction(P<0. 05). The breath holding index of posterior cerebral artery and the proportion of anterior and posterior circulating vascular motion reactivity were significantly lower in stenosis group with cerebral infarction and stenosis group without cerebral infarction than in control group (P<0. 05). The proportion of anterior and posterior circulating vascular motion reactivity was positively related with the visuospatial ability (r=0. 830, P<0. 05). Conclusion Patients with basilar artery stenosis may have cognitive impairment at different severity before cerebral infarction and its hemodynamic change is related with cognitive impairment.%目的 探讨基底动脉狭窄患者双侧大脑后动脉的脑血流自动调节变化与认知功能改变之间的关系.方法 选择基底动脉狭窄患者15例,并根据有无脑梗死分为狭窄无梗死组9例和狭窄梗死组6例,另选健康体检者10例为对照组.应用

  17. Evolutionary tuning of protein expression levels of a positively autoregulated two-component system.

    Directory of Open Access Journals (Sweden)

    Rong Gao

    2013-10-01

    Full Text Available Cellular adaptation relies on the development of proper regulatory schemes for accurate control of gene expression levels in response to environmental cues. Over- or under-expression can lead to diminished cell fitness due to increased costs or insufficient benefits. Positive autoregulation is a common regulatory scheme that controls protein expression levels and gives rise to essential features in diverse signaling systems, yet its roles in cell fitness are less understood. It remains largely unknown how much protein expression is 'appropriate' for optimal cell fitness under specific extracellular conditions and how the dynamic environment shapes the regulatory scheme to reach appropriate expression levels. Here, we investigate the correlation of cell fitness and output response with protein expression levels of the E. coli PhoB/PhoR two-component system (TCS. In response to phosphate (Pi-depletion, the PhoB/PhoR system activates genes involved in phosphorus assimilation as well as genes encoding themselves, similarly to many other positively autoregulated TCSs. We developed a bacteria competition assay in continuous cultures and discovered that different Pi conditions have conflicting requirements of protein expression levels for optimal cell fitness. Pi-replete conditions favored cells with low levels of PhoB/PhoR while Pi-deplete conditions selected for cells with high levels of PhoB/PhoR. These two levels matched PhoB/PhoR concentrations achieved via positive autoregulation in wild-type cells under Pi-replete and -deplete conditions, respectively. The fitness optimum correlates with the wild-type expression level, above which the phosphorylation output saturates, thus further increase in expression presumably provides no additional benefits. Laboratory evolution experiments further indicate that cells with non-ideal protein levels can evolve toward the optimal levels with diverse mutational strategies. Our results suggest that the natural

  18. 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 ...

  19. Acute Cerebral Insufficiency in Patients with Severe Forms of Alcoholic Psychoses

    Directory of Open Access Journals (Sweden)

    V. V. Zverev

    2006-01-01

    Full Text Available The paper summarizes the results of studies of cerebral metabolism in 38 patients with delirium tremens. The findings have led to the conclusion that the leading factor of the pathogenesis of acute cerebral insufficiency in this case is energy deficiency caused by impaired cerebral glucose utilization rather than hypoxia itself.

  20. Reversed Robin Hood Syndrome in the Light of Nonlinear Model of Cerebral Circulation

    Science.gov (United States)

    Piechna, A.; Cieslicki, K.

    2017-05-01

    The brain is supplied by the internal carotid and vertebro-basilar systems of vessels interconnected by arterial anastomoses and forming at the base of the brain a structure called the Circle of Willis (CoW). An active intrinsic ability of cerebral vascular bed maintains constant Cerebral Blood Flow (CBF) in a certain range of systemic pressure changes. This ability is called autoregulation and together with the redundant structure of the CoW guarantee maintaining CBF even in partial occlusion of supplying arteries. However, there are some situations when the combination of those two mechanisms causes an opposite effect called the Reversed Robin Hood Syndrome (RRHS). In this work we proposed a model of the CoW with autoregulation mechanism and investigated a RRHS which may occur in the case of Internal Carotid Artery (ICA) stenosis combined with hypercapnia. We showed and analyzed the mechanism of stealing the blood by the contralateral side of the brain. Our results were qualitatively compared with the clinical reports available in the literature.

  1. Analysis of interaction between TGF and the myogenic response in renal blood flow autoregulation

    DEFF Research Database (Denmark)

    Feldberg, R; Colding-Jørgensen, M; Holstein-Rathlou, N H

    1995-01-01

    The present study investigates the interaction between the tubuloglomerular feedback (TGF) response and the myogenic mechanism by use of a mathematical model. The two control mechanisms are implemented in a spatially distributed model of the rat renal juxtamedullary afferent arteriole. The model....... The contribution of TGF to smooth muscle activity is assumed to be a linear function of the glomerular capillary pressure. The results show that the myogenic response plays an important role in renal blood flow autoregulation. Without a myogenic response, mechanisms such as TGF that are localized in the distal...... located in the distal part of the afferent arteriole. An ascending myogenic response could enhance the regulatory efficiency of the TGF mechanism by increasing the open-loop gain of the system. However, such a synergistic interaction will only be observed when the two mechanisms operate on more or less...

  2. Double-wavelet approach to study frequency and amplitude modulation in renal autoregulation

    DEFF Research Database (Denmark)

    Sosnovtseva, Olga; Pavlov, A N; Mosekilde, E;

    2004-01-01

    Biological time series often display complex oscillations with several interacting rhythmic components. Renal autoregulation, for instance, involves at least two separate mechanisms both of which can produce oscillatory variations in the pressures and flows of the individual nephrons. Using double......-wavelet analysis we propose a method to examine how the instantaneous frequency and amplitude of a fast mode is modulated by the presence of a slower mode. Our method is applied both to experimental data from normotensive and hypertensive rats showing different oscillatory patterns and to simulation results...... obtained from a physiologically based model of the nephron pressure and flow control. We reveal a nonlinear interaction between the two mechanisms that regulate the renal blood flow in the form of frequency and amplitude modulation of the myogenic oscillations....

  3. Differences in dynamic autoregulation of renal blood flow between SHR and WKY rats

    DEFF Research Database (Denmark)

    Chen, Y M; Holstein-Rathlou, N H

    1993-01-01

    In halothane-anesthetized Wistar-Kyoto (WKY) rats the single-nephron blood flow and the proximal tubule pressure oscillate at a frequency of 35-50 mHz because of the operation of the tubuloglomerular feedback (TGF) mechanism. In spontaneously hypertensive rats (SHR) the oscillations are replaced...... by chaotic fluctuations. We sought to determine whether this change was associated with a change in the dynamic autoregulation of renal blood flow. In halothane-anesthetized 250- to 320-g SHR and WKY rats, renal blood flow was measured during "white noise" forcing of arterial blood pressure. The frequency...... to a decreased magnitude of the admittance in SHR at frequencies below 20-30 mHz. Above 70 mHz there was no significant difference in the transfer functions. Because TGF is active in the low frequency band (below approximately 100 mHz), whereas the myogenic mechanism also acts in the higher frequency band, we...

  4. Hepatic autoregulation

    DEFF Research Database (Denmark)

    Staehr, Peter; Hother-Nielsen, Ole; Beck-Nielsen, Henning

    2007-01-01

    The effect of increased glycogenolysis, simulated by galactose's conversion to glucose, on the contribution of gluconeogenesis (GNG) to hepatic glucose production (GP) was determined. The conversion of galactose to glucose is by the same pathway as glycogen's conversion to glucose, i.e., glucose 1......-phosphate --> glucose 6-phosphate --> glucose. Healthy men (n = 7) were fasted for 44 h. At 40 h, hepatic glycogen stores were depleted. GNG then contributed approximately 90% to a GP of approximately 8 micromol.kg(-1).min(-1). Galactose, 9 g/h, was infused over the next 4 h. The contribution of GNG to GP...... declined from approximately 90% to 65%, i.e., by approximately 2 micromol.kg(-1).min(-1). The rate of galactose conversion to blood glucose, measured by labeling the infused galactose with [1-(2)H]galactose (n = 4), was also approximately 2 micromol.kg(-1).min(-1). The 41st h GP rose by approximately 1...

  5. Autoregulation of coronary blood flow in the isolated beating pig heart.

    Science.gov (United States)

    Schampaert, Stéphanie; van 't Veer, Marcel; Rutten, Marcel C M; van Tuijl, Sjoerd; de Hart, Jurgen; van de Vosse, Frans N; Pijls, Nico H J

    2013-08-01

    The isolated beating pig heart model is an accessible platform to investigate the coronary circulation in its truly morphological and physiological state, whereas its use is beneficial from a time, cost, and ethical perspective. However, whether the coronary autoregulation is still intact is not known. Here, we study the autoregulation of coronary blood flow in the working isolated pig heart in response to brief occlusions of the coronary artery, to step-wise changes in left ventricular loading conditions and contractile states, and to pharmacologic vasodilating stimuli. Six slaughterhouse pig hearts (473 ± 40 g) were isolated, prepared, and connected to an external circulatory system. Through coronary reperfusion and controlled cardiac loading, physiological cardiac performance was achieved. After release of a coronary occlusion, coronary blood flow rose rapidly to an equal (maximum) level as the flow during control beats, independent of the duration of occlusion. Moreover, a linear relation was found between coronary blood flow and coronary driving pressure for a wide variation of preload, afterload, and contractility. In addition, intracoronary administration of papaverine did not yield a transient increase in blood flow indicating the presence of maximum coronary hyperemia. Together, this indicates that the coronary circulation in the isolated beating pig heart is in a permanent state of maximum hyperemia. This makes the model excellently suitable for testing and validating cardiovascular devices (i.e., heart valves, stent grafts, and ventricular assist devices) under well-controlled circumstances, whereas it decreases the necessity of sacrificing large mammalians for performing classical animal experiments. © 2013, Copyright the Authors. Artificial Organs © 2013 Wiley Periodicals, Inc. and International Center for Artificial Organs and Transplantation.

  6. 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.

  7. Cerebral toxoplasmosis in AIDS

    Energy Technology Data Exchange (ETDEWEB)

    Christ, F.; Steudel, H.; Klotz, D.

    1986-02-01

    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.

  8. EFFECT OF LEFT VENTRICULAR SYSTOLIC DYSFUNCTION ON CEREBRAL HEMODYNAMICS IN PATIENTS WITH ACUTE MYOCARDIAL INFARCTION (THE RESULTS OF OBSERVATIONAL STUDIES

    Directory of Open Access Journals (Sweden)

    V. E. Kulikov

    2015-12-01

    Full Text Available Aim. To study the effect of left ventricular (LV systolic dysfunction on cerebral hemodynamic in patients with ST segment elevation myocardial infarction (STEMI during acute period. Material and methods. Cerebral hemodynamics ultrasound assessment was performed in the extra-and intracranial vessels in 118 patients with STEMI. Results. Significant changes in cerebral hemodynamics were found in LV systolic dysfunction with ejection fraction (LVEF ≤40% due to hemispheric blood flow asymmetry in the middle cerebral artery (MCA as large as 45.1±6.7% with correlation coefficient r=-0.87. Compensation of cerebral blood flow was manifested in vasoconstriction or vasodilation (resistive index 0.63-0.76 and 0.49-0.43 c.u., respectively. Conclusion. A strong relationship between LV systolic dysfunction and cerebral hemodynamic was found in patients with STEMI. It was manifested in significant contralateral hemispheric blood flow asymmetry in MCA in patients with LVEF ≤40%. Reduction in cerebral blood flow velocity activated autoregulation mechanism in the form of vasoconstriction or vasodilation.

  9. Visual Impairment

    Science.gov (United States)

    ... Surgery? Choosing the Right Sport for You Shyness Visual Impairment KidsHealth > For Teens > Visual Impairment Print A A ... with the brain, making vision impossible. What Is Visual Impairment? Many people have some type of visual problem ...

  10. Clinical practice: swallowing problems in cerebral palsy.

    NARCIS (Netherlands)

    Erasmus, C.E.; Hulst, K. van; Rotteveel, J.J.; Willemsen, M.A.A.P.; Jongerius, P.H.

    2012-01-01

    Cerebral palsy (CP) is the most common physical disability in early childhood. The worldwide prevalence of CP is approximately 2-2.5 per 1,000 live births. It has been clinically defined as a group of motor, cognitive, and perceptive impairments secondary to a non-progressive defect or lesion of the

  11. Clinical practice: swallowing problems in cerebral palsy.

    NARCIS (Netherlands)

    Erasmus, C.E.; Hulst, K. van; Rotteveel, J.J.; Willemsen, M.A.A.P.; Jongerius, P.H.

    2012-01-01

    Cerebral palsy (CP) is the most common physical disability in early childhood. The worldwide prevalence of CP is approximately 2-2.5 per 1,000 live births. It has been clinically defined as a group of motor, cognitive, and perceptive impairments secondary to a non-progressive defect or lesion of the

  12. Sirt1 in cerebral ischemia

    Directory of Open Access Journals (Sweden)

    Kevin B Koronowski

    2015-01-01

    Full Text Available Cerebral ischemia is among the leading causes of death worldwide. It is characterized by a lack of blood flow to the brain that results in cell death and damage, ultimately causing motor, sensory, and cognitive impairments. Today, clinical treatment of cerebral ischemia, mostly stroke and cardiac arrest, is limited and new neuroprotective therapies are desperately needed. The Sirtuin family of oxidized nicotinamide adenine dinucleotide (NAD +-dependent deacylases has been shown to govern several processes within the central nervous system as well as to possess neuroprotective properties in a variety of pathological conditions such as Alzheimer′s Disease, Parkinson′s Disease, and Huntington′s Disease, among others. Recently, Sirt1 in particular has been identified as a mediator of cerebral ischemia, with potential as a possible therapeutic target. To gather studies relevant to this topic, we used PubMed and previous reviews to locate, select, and resynthesize the lines of evidence presented here. In this review, we will first describe some functions of Sirt1 in the brain, mainly neurodevelopment, learning and memory, and metabolic regulation. Second, we will discuss the experimental evidence that has implicated Sirt1 as a key protein in the regulation of cerebral ischemia as well as a potential target for the induction of ischemic tolerance.

  13. Sirt1 in cerebral ischemia

    Science.gov (United States)

    Koronowski, Kevin B.; Perez-Pinzon, Miguel A.

    2015-01-01

    Cerebral ischemia is among the leading causes of death worldwide. It is characterized by a lack of blood flow to the brain that results in cell death and damage, ultimately causing motor, sensory, and cognitive impairments. Today, clinical treatment of cerebral ischemia, mostly stroke and cardiac arrest, is limited and new neuroprotective therapies are desperately needed. The Sirtuin family of oxidized nicotinamide adenine dinucleotide (NAD+)-dependent deacylases has been shown to govern several processes within the central nervous system as well as to possess neuroprotective properties in a variety of pathological conditions such as Alzheimer’s Disease, Parkinson’s Disease, and Huntington’s Disease, among others. Recently, Sirt1 in particular has been identified as a mediator of cerebral ischemia, with potential as a possible therapeutic target. To gather studies relevant to this topic, we used PubMed and previous reviews to locate, select, and resynthesize the lines of evidence presented here. In this review, we will first describe some functions of Sirt1 in the brain, mainly neurodevelopment, learning and memory, and metabolic regulation. Second, we will discuss the experimental evidence that has implicated Sirt1 as a key protein in the regulation of cerebral ischemia as well as a potential target for the induction of ischemic tolerance. PMID:26819971

  14. Autoregulation of TDP-43 mRNA levels involves interplay between transcription, splicing, and alternative polyA site selection.

    Science.gov (United States)

    Avendaño-Vázquez, S Eréndira; Dhir, Ashish; Bembich, Sara; Buratti, Emanuele; Proudfoot, Nicholas; Baralle, Francisco E

    2012-08-01

    TDP-43 is a critical RNA-binding factor associated with pre-mRNA splicing in mammals. Its expression is tightly autoregulated, with loss of this regulation implicated in human neuropathology. We demonstrate that TDP-43 overexpression in humans and mice activates a 3' untranslated region (UTR) intron, resulting in excision of the proximal polyA site (PAS) pA(1). This activates a cryptic PAS that prevents TDP-43 expression through a nuclear retention mechanism. Superimposed on this process, overexpression of TDP-43 blocks recognition of pA(1) by competing with CstF-64 for PAS binding. Overall, we uncover complex interplay between transcription, splicing, and 3' end processing to effect autoregulation of TDP-43.

  15. Thyroglobulin in smoking mothers and their newborns at delivery suggests autoregulation of placental iodide transport overcoming thiocyanate inhibition

    DEFF Research Database (Denmark)

    Andersen, Stine L; Backman Nøhr, Susanne; Wu, Chun S

    2013-01-01

    ). The pregnant women reported on intake of iodine-containing supplements during pregnancy and Tg in maternal serum at delivery and in cord serum were analyzed. RESULTS: In a context of mild-to-moderate iodine deficiency, smoking mothers had significantly higher serum Tg than nonsmoking mothers (mean Tg smokers...... maternal smoking, but compensatory autoregulation of iodide transport differs between organs. The extent of autoregulation of placental iodide transport remains to be clarified. OBJECTIVE: To compare the impact of maternal smoking on thyroglobulin (Tg) levels in maternal serum at delivery and in cord serum...... as markers of maternal and fetal iodine deficiency. METHODS: One hundred and forty healthy, pregnant women admitted for delivery and their newborns were studied before the iodine fortification of salt in Denmark. Cotinine in urine and serum classified mothers as smokers (n=50) or nonsmokers (n=90...

  16. Impaired Coronary Autoregulation Is Associated With Long-term Fatal Events in Patients With Stable Coronary Artery Disease

    NARCIS (Netherlands)

    van de Hoef, Tim P.; Bax, Matthijs; Damman, Peter; Delewi, Ronak; Hassell, Mariella E. C. J.; Piek, Martijn A.; Chamuleau, Steven A. J.; Voskuil, Michiel; van Eck-Smit, Berthe L. F.; Verberne, Hein J.; Henriques, Jose P. S.; Koch, Karel T.; de Winter, Robbert J.; Tijssen, Jan G. P.; Piek, Jan J.; Meuwissen, Martijn

    2013-01-01

    Background-Abnormalities in the coronary microcirculation are increasingly recognized as an elementary component of ischemic heart disease, which can be accurately assessed by coronary flow velocity reserve in reference vessels (refCFVR). We studied the prognostic value of refCFVR for long-term mort

  17. REHABILITATION OF PERSONS WITH CEREBRAL PALSY

    Directory of Open Access Journals (Sweden)

    Natasa CICEVSKA-JOVANOVA

    2000-06-01

    Full Text Available The persons with cerebral palsy with motoric impairments as a primary demmages, they have other following disables: visual impairments, hearing impairments, speech disables and very often they have intellectual difficulties.This persons in school have problems with writing, they couldn’t oriented in the books, they have difficulties with manipulation with school’s supplies and didactic materials, they couldn’t follow the order of the words in the line during the reading and the writing and etc.Using the exercises of psycho-motor reeducation, all before mentioned difficulties and problems can be mitigate or disappear.

  18. Visuospatial Functioning in Cerebral Amyloid Angiopathy : A Pilot Study

    NARCIS (Netherlands)

    Valenti, Raffaella; Charidimou, Andreas; Xiong, Li; Boulouis, Gregoire; Fotiadis, Panagiotis; Ayres, Alison; Riley, Grace; Kuijf, Hugo J.|info:eu-repo/dai/nl/341734888; Reijmer, Yael D.; Pantoni, Leonardo; Gurol, M. Edip; Davidsdottir, Sigurros; Greenberg, Steven M.; Viswanathan, Anand

    2017-01-01

    Cerebral amyloid angiopathy (CAA) is a contributor to cognitive impairment in the elderly. We hypothesized that the posterior cortical predilection of CAA would cause visual-processing impairment. We systematically evaluated visuospatial abilities in 22 non-demented CAA patients. Neurocognitive

  19. Effect of Repetitive Transcranial Magnetic Stimulation on Patients With Mild Cognitive Impairment After Cerebral Infarction%重复经颅磁刺激对脑梗死后轻度认知功能障碍患者的影响

    Institute of Scientific and Technical Information of China (English)

    黄旭玲

    2015-01-01

    ObjectiveTo study the effect of repetitive transcranial magnetic stimulation on the cognitive function of patients with mild cognitive impairment after cerebral infarction.Methods 40 patients with mild cognitive impairment after cerebral infarction in our hospital from January 2013 to January 2015 were randomly selected,and the patients were treated with transcranial magnetic stimulation for 4 courses. The changes of cognitive function were compared before and after treatment. Results Compared with before treatment,the latency of P300 in patients was shorter(P<0.05),amplitude was increased(P<0.05),MoCA scale scores were improved,the total score of MoCA score and delayed memory improved significantly(P<0.05).Conclusion In patients with mild cognitive impairment after cerebral infarction,repetitive transcranial magnetic stimulation can improve the patients'cognitive function and improve the memory.%目的:研究脑梗死后轻度认知功能障碍患者进行重复经颅磁刺激治疗的效果。方法随机选取2013年1月~2015年1月入住我院脑梗死后轻度认知功能障碍患者40例,对所选患者进行重复经颅磁刺激治疗,治疗4个疗程后,对比治疗前后患者认知功能的变化。结果与治疗前相比,患者P300的潜伏期缩短(P<0.05)、波幅增高(P<0.05)、MoCA量表的各项评分均有所改善,MoCA量表评分总分和延迟记忆改善(P<0.05)。结论对于脑梗死后轻度认知功能障碍患者,重复经颅磁刺激可以改善患者认知功能,提高患者的记忆力。

  20. [Ischaemic lesions of cerebral after carotid stenting].

    Science.gov (United States)

    Medvedev, R B; Tanashian, M M; Kuntsevich, G I; Lagoda, O V; Skrylev, S I; Krotenkova, M V; Koshcheev, A Iu; Suslin, A S; Gemdzhian, É G

    2015-01-01

    Carotid angioplasty with stenting is a reliable method of primary and secondary prevention of ischaemic stroke in patients with stenosing lesions of the internal carotid artery. However, carrying out such operations is sometimes associated with risk for the development of intraoperative impairments of cerebral circulation due to arterioarterial embolism in cerebral arteries, as well as vasospasm. Presented herein are the results of following up a total of 64 patients with pronounced atherosclerotic lesions of internal carotid arteries (>70%) - "symptomatic" and "asymptomatic", undergoing carotid stenting. Acute foci of ischaemia in the brain after stenting according to the findings of diffusion-weighted magnetic resonance tomography were revealed in 40% of cases, and in only 6% of patients they manifested themselves by symptoms of acute cerebral circulatory impairment. We revealed a direct correlation between the number, size of infarctions in the brain, and the appearance of neurological symptomatology. Intraoperative monitoring of blood flow in the middle cerebral artery during stenting makes it possible to predict the appearance of acute foci of cerebral ischaemia, to specify the genesis of perioperative stroke, as well as to evaluate clinical significance of vasospasm and material microembolism. The obtained findings should concentrate neurologists' attention on active postoperative follow up of patients subjected to carotid angioplasty with stenting in order to perform adequate personified neuroprotective correction, including preventive one.

  1. Effects of midazolam on cerebral blood flow in human volunteers

    Energy Technology Data Exchange (ETDEWEB)

    Forster, A.; Juge, O.; Morel, D.

    1982-06-01

    The effects of intravenously administered midazolam on cerebral blood flow were evaluated in eight healthy volunteers using the /sup 133/Xe inhalation technique. Six minutes after an intravenous dose of 0.15 mg/kg midazolam, the cerebral blood flow decreased significantly (P less than 0.001) from a value of 40.6 +/- 3.3 to a value of 27.0 +/- 5.0 ml . 100 g-1 . min-1. Cerebrovascular resistance (CVR) increased from 2.8 +/- 0.2 to 3.9 to 0.6 mmHg/(ml . 100 g-1 . min-1)(P less than 0.001). Mean arterial blood pressure decreased significantly (P less than 0.05) from 117 +/- 8 to 109 +/- 9 mmHg and arterial carbon dioxide tension increased from 33.9 +/- 2.3 to 38.6 +/- 3.2 mmHg (P less than 0.05). Arterial oxygen tension remained stable throughout the study, 484 +/- 95 mmHg before the administration of midazolam and 453 +/- 76 mmHg after. All the subjects slept after the injection of the drug and had anterograde amnesia of 24.5 +/- 5 min. The decrease in mean arterial blood pressure was probably not important since it remained in the physiologic range for cerebral blood flow autoregulation. The increase in arterial carbon dioxide tension observed after the midazolam injection may have partially counteracted the effect of this new benzodiazepine on cerebral blood flow. Our data suggest that midazolam might be a safe agent to use for the induction of anethesia in neurosurgical patients with intracranial hypertension.

  2. 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...

  3. Cognitive impairment and preferences for current health

    Directory of Open Access Journals (Sweden)

    Tsevat Joel

    2009-01-01

    Full Text Available Abstract Background We assessed preferences for current health using the visual analogue scale (VAS, standard gamble (SG, time trade-off (TTO, and willingness to pay (WTP in patients with cerebral aneurysms, a population vulnerable to cognitive deficits related to aneurysm bleeding or treatment. Methods We measured VAS, SG, TTO, and WTP values for current health in 165 outpatients with cerebral aneurysms. We assessed cognitive impairment with the Mini Mental State Examination (MMSE; scores Results Eleven patients (7% had MMSE scores Conclusion Cognitive impairment is associated with lower preferences for current health in patients with cerebral aneurysms. Cognitively impaired patients have poor inter-preference test correlations and different response distributions compared to unimpaired patients.

  4. XRN2 Autoregulation and Control of Polycistronic Gene Expresssion in Caenorhabditis elegans

    Science.gov (United States)

    2016-01-01

    XRN2 is a conserved 5’→3’ exoribonuclease that complexes with proteins that contain XRN2-binding domains (XTBDs). In Caenorhabditis elegans (C. elegans), the XTBD-protein PAXT-1 stabilizes XRN2 to retain its activity. XRN2 activity is also promoted by 3'(2'),5'-bisphosphate nucleotidase 1 (BPNT1) through hydrolysis of an endogenous XRN inhibitor 3’-phosphoadenosine-5'-phosphate (PAP). Here, we find through unbiased screening that loss of bpnt-1 function suppresses lethality caused by paxt-1 deletion. This unexpected finding is explained by XRN2 autoregulation, which occurs through repression of a cryptic promoter activity and destabilization of the xrn-2 transcript. De-repression appears to be triggered such that more robust XRN2 perturbation, by elimination of both PAXT-1 and BPNT1, is less detrimental to worm viability than absence of PAXT-1 alone. Indeed, we find that two distinct XRN2 repression mechanisms are alleviated at different thresholds of XRN2 inactivation. Like more than 15% of C. elegans genes, xrn-2 occurs in an operon, and we identify additional operons under its control, consistent with a broader function of XRN2 in polycistronic gene regulation. Regulation occurs through intercistronic regions that link genes in an operon, but a part of the mechanisms may allow XRN2 to operate on monocistronic genes in organisms lacking operons. PMID:27631780

  5. XRN2 Autoregulation and Control of Polycistronic Gene Expresssion in Caenorhabditis elegans.

    Science.gov (United States)

    Miki, Takashi S; Carl, Sarah H; Stadler, Michael B; Großhans, Helge

    2016-09-01

    XRN2 is a conserved 5'→3' exoribonuclease that complexes with proteins that contain XRN2-binding domains (XTBDs). In Caenorhabditis elegans (C. elegans), the XTBD-protein PAXT-1 stabilizes XRN2 to retain its activity. XRN2 activity is also promoted by 3'(2'),5'-bisphosphate nucleotidase 1 (BPNT1) through hydrolysis of an endogenous XRN inhibitor 3'-phosphoadenosine-5'-phosphate (PAP). Here, we find through unbiased screening that loss of bpnt-1 function suppresses lethality caused by paxt-1 deletion. This unexpected finding is explained by XRN2 autoregulation, which occurs through repression of a cryptic promoter activity and destabilization of the xrn-2 transcript. De-repression appears to be triggered such that more robust XRN2 perturbation, by elimination of both PAXT-1 and BPNT1, is less detrimental to worm viability than absence of PAXT-1 alone. Indeed, we find that two distinct XRN2 repression mechanisms are alleviated at different thresholds of XRN2 inactivation. Like more than 15% of C. elegans genes, xrn-2 occurs in an operon, and we identify additional operons under its control, consistent with a broader function of XRN2 in polycistronic gene regulation. Regulation occurs through intercistronic regions that link genes in an operon, but a part of the mechanisms may allow XRN2 to operate on monocistronic genes in organisms lacking operons.

  6. XRN2 Autoregulation and Control of Polycistronic Gene Expresssion in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Takashi S Miki

    2016-09-01

    Full Text Available XRN2 is a conserved 5'→3' exoribonuclease that complexes with proteins that contain XRN2-binding domains (XTBDs. In Caenorhabditis elegans (C. elegans, the XTBD-protein PAXT-1 stabilizes XRN2 to retain its activity. XRN2 activity is also promoted by 3'(2',5'-bisphosphate nucleotidase 1 (BPNT1 through hydrolysis of an endogenous XRN inhibitor 3'-phosphoadenosine-5'-phosphate (PAP. Here, we find through unbiased screening that loss of bpnt-1 function suppresses lethality caused by paxt-1 deletion. This unexpected finding is explained by XRN2 autoregulation, which occurs through repression of a cryptic promoter activity and destabilization of the xrn-2 transcript. De-repression appears to be triggered such that more robust XRN2 perturbation, by elimination of both PAXT-1 and BPNT1, is less detrimental to worm viability than absence of PAXT-1 alone. Indeed, we find that two distinct XRN2 repression mechanisms are alleviated at different thresholds of XRN2 inactivation. Like more than 15% of C. elegans genes, xrn-2 occurs in an operon, and we identify additional operons under its control, consistent with a broader function of XRN2 in polycistronic gene regulation. Regulation occurs through intercistronic regions that link genes in an operon, but a part of the mechanisms may allow XRN2 to operate on monocistronic genes in organisms lacking operons.

  7. The potential roles of strigolactones and brassinosteroids in the autoregulation of nodulation pathway.

    Science.gov (United States)

    Foo, E; Ferguson, B J; Reid, J B

    2014-05-01

    The number of nodules formed on a legume root system is under the strict genetic control of the autoregulation of nodulation (AON) pathway. Plant hormones are thought to play a role in AON; however, the involvement of two hormones recently described as having a largely positive role in nodulation, strigolactones and brassinosteroids, has not been examined in the AON process. A genetic approach was used to examine if strigolactones or brassinosteroids interact with the AON system in pea (Pisum sativum). Double mutants between shoot-acting (Psclv2, Psnark) and root-acting (Psrdn1) mutants of the AON pathway and strigolactone-deficient (Psccd8) or brassinosteroid-deficient (lk) mutants were generated and assessed for various aspects of nodulation. Strigolactone production by AON mutant roots was also investigated. Supernodulation of the roots was observed in both brassinosteroid- and strigolactone-deficient AON double-mutant plants. This is despite the fact that the shoots of these plants displayed classic strigolactone-deficient (increased shoot branching) or brassinosteroid-deficient (extreme dwarf) phenotypes. No consistent effect of disruption of the AON pathway on strigolactone production was found, but root-acting Psrdn1 mutants did produce significantly more strigolactones. No evidence was found that strigolactones or brassinosteroids act downstream of the AON genes examined. While in pea the AON mutants are epistatic to brassinosteroid and strigolactone synthesis genes, we argue that these hormones are likely to act independently of the AON system, having a role in the promotion of nodule formation.

  8. Brain mitochondrial function in a murine model of cerebral malaria and the therapeutic effects of rhEPO

    DEFF Research Database (Denmark)

    Karlsson, Michael; Hempel, Casper; Sjövall, Fredrik

    2013-01-01

    Cerebral malaria (CM) is a life-threatening complication of Plasmodium falciparum infection. The pathogenesis of CM is complex. Cerebral metabolic dysfunction is implicated in CM, which may be caused by both an impaired cerebral microcirculation and a dysregulated inflammatory response affecting ...

  9. Dyke-Davidoff-Masson syndrome: case report of fetal unilateral ventriculomegaly and hypoplastic left middle cerebral artery

    OpenAIRE

    Piro, E.; Piccione, M.; Marrone, G; M. Giuffrè; Corsello, G

    2013-01-01

    Prenatal ultrasonographic detection of unilateral cerebral ventriculomegaly arises suspicion of pathological condition related to cerebrospinal fluid flow obstruction or cerebral parenchimal pathology. Dyke-Davidoff-Masson syndrome is a rare condition characterized by cerebral hemiatrophy, calvarial thickening, skull and facial asymmetry, contralateral hemiparesis, cognitive impairment and seizures. Congenital and acquired types are recognized and have been described, mainly in late childhood...

  10. Progressive cerebral atrophy in neuromyelitis optica.

    Science.gov (United States)

    Warabi, Yoko; Takahashi, Toshiyuki; Isozaki, Eiji

    2015-12-01

    We report two cases of neuromyelitis optica patients with progressive cerebral atrophy. The patients exhibited characteristic clinical features, including elderly onset, secondary progressive tetraparesis and cognitive impairment, abnormally elevated CSF protein and myelin basic protein levels, and extremely highly elevated serum anti-AQP-4 antibody titer. Because neuromyelitis optica pathology cannot switch from an inflammatory phase to the degenerative phase until the terminal phase, neuromyelitis optica rarely appears as a secondary progressive clinical course caused by axonal degeneration. However, severe intrathecal inflammation and massive destruction of neuroglia could cause a secondary progressive clinical course associated with cerebral atrophy in neuromyelitis optica patients.

  11. Feeding difficulties in children with cerebral palsy.

    Science.gov (United States)

    Andrew, Morag J; Parr, Jeremy R; Sullivan, Peter B

    2012-12-01

    Feeding difficulties are common in children with cerebral palsy and have an effect on growth, nutritional state, general health, social interaction and behaviour and developmental outcomes. Many factors have an effect on feeding ability. Identification of these factors and amelioration of their impact on feeding difficulties is essential to promote adequate growth and nutrition. Appropriate assessment and management is best achieved by a multiprofessional team skilled in the care of children with cerebral palsy and feeding impairments. Feeding difficulties must be considered within the wider context of family and social circumstance.

  12. United Cerebral Palsy

    Science.gov (United States)

    ... be sure to follow us on Twitter . United Cerebral Palsy UCP educates, advocates and provides support services to ... Partners Merz Logo Sprint Relay Copyright © 2015 United Cerebral Palsy 1825 K Street NW Suite 600 Washington, DC ...

  13. Employees with Cerebral Palsy

    Science.gov (United States)

    ... problems in the muscles or nerves. Instead, faulty development or damage to motor areas in the brain disrupt the brain's ability to adequately control movement and posture (United Cerebral Palsy, 2010). "Cerebral" refers to the ...

  14. Cerebral Palsy (For Kids)

    Science.gov (United States)

    ... CPR: A Real Lifesaver Kids Talk About: Coaches Cerebral Palsy KidsHealth > For Kids > Cerebral Palsy Print A A A What's in this article? ... the first word you spoke? For kids with cerebral palsy, called CP for short, taking a first step ...

  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. 认知功能电话问卷修订版在缺血性脑卒中后认知功能研究中的应用%Telephone interview for cognitive status-modified in study of cognitive impairment after cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    吕志红; 刘晓加

    2016-01-01

    Objective To study the variation characteristics of cognitive impairment and its influencing factors using telephone interview for cognitive status-modified (TICS-m) in patients after cerebral ischemia,and evaluate the application value of TICS-m.Methods Ninety-five patients with cerebral ischemia,matched the criteria and admitted to our hospital from December 2014 to December 2015,were chosen.Their related information was recorded,their cognitive function was assessed by face-to-face neuropsychological tests,including Montreal Cognitive Assessment (MoCA),Hamilton Depression Rating Scale,activities of daily living (ADL) and Chinese Neuropsychiatric Inventory (CNPI),in the acute stage (10-14 d),and then,their cognitive function was assessed by TICS-m 4,12 and 18 weeks after cerebral ischemia and their rehabilitation was followed up.Results The incidence of cognitive impairment after cerebral ischemia in the acute stage was 78.9%;when cutoffs of dementia was <28 points and mild cognitive impairment (MCI) was 28-33 points in TICS-m,the incidences of cognitive impairment 4,12 and 18 weeks after cerebral ischemia were 69.4% (MCI:45.8%,dementia:23.6%),57.3% (MCI:42.6%,dementia:14.8%),44.9% (MCI:34.7%,dementia:10.2%).And the TICS-m total scores 12 and 18 weeks after cerebral ischemia were significantly increased than that 4 weeks after cerebral ischemia,amplification reaching to 7.9% and 10.7% (P<0.05);subtests analysis indicated that 12 and 18 weeks after cerebral ischemia,the memory recovered obviously:the scores were significantly increased,amplification reaching to 34.5% and 49.0% as compared with those 4 weeks after the cerebral ischemia (P<0.05).Logistic regression analysis indicated that age (OR=66.615,P=0.001,95%CI:5.449-814.349),education level (OR=0.134,P=0.009,95%CI:0.029-0.608) and work type (OR=0.090,P=0.004,95%CI:0.017-0.464) were closely related to the cognitive impairment after cerebral ischemia.The follow-up visit

  17. PKA, novel PKC isoforms, and ERK is mediating PACAP auto-regulation via PAC1R in human neuroblastoma NB-1 cells.

    Science.gov (United States)

    Georg, Birgitte; Falktoft, Birgitte; Fahrenkrug, Jan

    2016-12-01

    The neuropeptide PACAP is expressed throughout the central and peripheral nervous system where it modulates diverse physiological functions including neuropeptide gene expression. We here report that in human neuroblastoma NB-1 cells PACAP transiently induces its own expression. Maximal PACAP mRNA expression was found after stimulation with PACAP for 3h. PACAP auto-regulation was found to be mediated by activation of PACAP specific PAC1Rs as PACAP had >100-fold higher efficacy than VIP, and the PAC1R selective agonist Maxadilan potently induced PACAP gene expression. Experiments with pharmacological kinase inhibitors revealed that both PKA and novel but not conventional PKC isozymes were involved in the PACAP auto-regulation. Inhibition of MAPK/ERK kinase (MEK) also impeded the induction, and we found that PKA, novel PKC and ERK acted in parallel and were thus not part of the same pathways. The expression of the transcription factor EGR1 previously ascribed as target of PACAP signalling was found to be transiently induced by PACAP and pharmacological inhibition of either PKC or MEK1/2 abolished PACAP mediated EGR1 induction. In contrast, inhibition of PKA mediated increased PACAP mediated EGR1 induction. Experiments using siRNA against EGR1 to lower the expression did however not affect the PACAP auto-regulation indicating that this immediate early gene product is not part of PACAP auto-regulation in NB-1 cells. We here reveal that in NB-1 neuroblastoma cells, PACAP induces its own expression by activation of PAC1R, and that the signalling is different from the PAC1R signalling mediating induction of VIP in the same cells. PACAP auto-regulation depends on parallel activation of PKA, novel PKC isoforms, and ERK, while EGR1 does not seem to be part of the PACAP auto-regulation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Anestesia e paralisia cerebral Anestesia y parálisis cerebral Anesthesia and cerebral palsy

    Directory of Open Access Journals (Sweden)

    Március Vinícius M Maranhão

    2005-12-01

    riesgo, fisiopatología, cuadro clínico, diagnóstico, terapéuticas utilizadas bien como evaluación pre-operatoria, medicación pre-anestésica, manoseo intra y posoperatorio, analgesia posoperatoria y dolor crónico. CONCLUSIONES: El anestesista desempeña un papel importante en la disminución de la morbidez y mortalidad anestésico-quirúrgica en pacientes portadores de parálisis cerebral. El conocimiento de la fisiopatología de los diferentes tipos de parálisis cerebral bien como de las enfermedades asociadas y sus terapéuticas es imprescindible, pues permite al anestesista anticipar y precaver complicaciones intra y posoperatorias en este tipo de paciente.BACKGROUND AND OBJECTIVES: Cerebral palsy (CP is a non-progressive disease induced by CNS injury, which leads to patients' motor impairment. CP patients are often submitted to surgical procedures due to usual diseases and some surgical situations related with CP. The aim of this article was to review cerebral palsy aspects of interest to anesthesiologists to allow an adequate pre, intra and postoperative management of these patients. CONTENTS: This article addresses cerebral palsy aspects such as etiology, classification, risk factors, pathophysiology, clinical presentation, diagnosis and therapies and, in addition to preoperative evaluation, preanesthetic medication, intra and postoperative management, postoperative analgesia and chronic pain. CONCLUSIONS: Anesthesiologists play an important role in decreasing anesthetic-surgical morbidity and mortality of cerebral palsy patients. The understanding of different aspects of cerebral palsy pathophysiologies, in addition to those of associated diseases and their therapies is paramount, because it allows anesthesiologists to anticipate and prevent intra and postoperative complications in this type of patient.

  19. Cerebral microangiopathies; Zerebrale Mikroangiopathien

    Energy Technology Data Exchange (ETDEWEB)

    Linn, Jennifer [Klinikum der Universitaet Muenchen (Germany). Abt. fuer Neuroradiologie

    2011-03-15

    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.)

  20. [Chronic cerebral ischemia associated with Raynaud's syndrome].

    Science.gov (United States)

    Putilina, M V

    2015-01-01

    Over the last years, a number of patients with chronic cerebral ischemia has been increased significantly. Compensatory possibilities of the brain and cerebral circulatory system are so great that even serious disturbances of blood circulation could not cause clinical signs of brain dysfunction for a long time. At the same time, long-term ischemia can lead to peripheral local disturbances of microcirculation that is appears to be a first signal of the problems with homeostasis. Therefore, Raynaud's syndrome may be one of the predictors of standard symptoms of chronic cerebral ischemia (CCI). This phenomenon is explicitly considered as a sign of blood circulation impairment while the pathogenetic mechanism of vascular arterial bed instability is completely ignored. Detailed study of clinical correlations of Raynaud's syndrome in CCI would help to develop a common pharmacotherapeutic approach to its treatment.