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Sample records for cerebral autoregulation dynamics

  1. Dynamic Cerebral Autoregulation after Cardiopulmonary Bypass

    DEFF Research Database (Denmark)

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

    2016-01-01

    Background Cerebral hemodynamic disturbances in the peri- or postoperative period may contribute to postoperative cognitive dysfunction (POCD) in patients undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB). We therefore examined dynamic cerebral autoregulation (d......CA) post-CPB and changes in neurocognitive function in patients that had undergone CABG. Materials and Methods We assessed dCA by transfer function analysis of spontaneous oscillations between arterial blood pressure and middle cerebral artery blood flow velocity measured by transcranial Doppler ultrasound...

  2. Dynamic cerebral autoregulation measured with coherent hemodynamics spectroscopy (CHS)

    Science.gov (United States)

    Kainerstorfer, Jana M.; Sassaroli, Angelo; Tgavalekos, Kristen T.; Fantini, Sergio

    2015-03-01

    Coherent Hemodynamics Spectroscopy (CHS) is a novel technique for non-invasive measurements of local microcirculation quantities such as the capillary blood transit times and dynamic autoregulation. The basis of CHS is to measure, for instance with near-infrared spectroscopy (NIRS), peripheral coherent hemodynamic changes that are induced by controlled perturbations in the systemic mean arterial pressure (MAP). In this study, the MAP perturbation was induced by the fast release of two pneumatic cuffs placed around the subject's thighs after they were kept inflated (at 200 mmHg) for two minutes. The resulting transient changes in cerebral oxy- (O) and deoxy- (D) hemoglobin concentrations measured with NIRS on the prefrontal cortex are then described by a novel hemodynamic model, from which quantifiable parameters such as the capillary blood transit time and a cutoff frequency for cerebral autoregulation are obtained. We present results on eleven healthy volunteers in a protocol involving measurements during normal breathing and during hyperventilation, which is known to cause a hypocapnia-induced increase in cerebral autoregulation. The measured capillary transit time was unaffected by hyperventilation (normal breathing: 1.1±0.1 s; hyperventilation: 1.1±0.1 s), whereas the cutoff frequency of autoregulation, which increases for higher autoregulation efficiency, was indeed found to be significantly greater during hyperventilation (normal breathing: 0.017±0.002 Hz; hyperventilation: 0.034±0.005 Hz). These results provide a validation of local cerebral autoregulation measurements with the new technique of CHS.

  3. Unconstrained parameter estimation for assessment of dynamic cerebral autoregulation.

    Science.gov (United States)

    Chacón, M; Nuñez, N; Henríquez, C; Panerai, R B

    2008-10-01

    Measurement of dynamic cerebral autoregulation (CA), the transient response of cerebral blood flow (CBF) to changes in arterial blood pressure (ABP), has been performed with an index of autoregulation (ARI), related to the parameters of a second-order differential equation model, namely gain (K), damping factor (D) and time constant (T). Limitations of the ARI were addressed by increasing its numerical resolution and generalizing the parameter space. In 16 healthy subjects, recordings of ABP (Finapres) and CBF velocity (ultrasound Doppler) were performed at rest, before, during and after 5% CO(2) breathing, and for six repeated thigh cuff maneuvers. The unconstrained model produced lower predictive error (p < 0.001) than the original model. Unconstrained parameters (K'-D'-T') were significantly different from K-D-T but were still sensitive to different measurement conditions, such as the under-regulation induced by hypercapnia. The intra-subject variability of K' was significantly lower than that of the ARI and this parameter did not show the unexpected occurrences of zero values as observed with the ARI and the classical value of K. These results suggest that K' could be considered as a more stable and reliable index of dynamic autoregulation than ARI. Further studies are needed to validate this new index under different clinical conditions. PMID:18799835

  4. 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.

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

    DEFF Research Database (Denmark)

    Janzarik, Wibke G; Ehlers, Elena; Ehmann, Renata; Gerds, Thomas A; Schork, Joscha; Mayer, Sebastian; Gabriel, Boris; Weiller, Cornelius; Prömpeler, Heinrich; Reinhard, Matthias

    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...... 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 and...

  6. 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...... in arterial carbon dioxide tension explains the improved dynamic cerebral autoregulation and the reduced cerebral perfusion encountered in healthy subjects during endotoxemia.......-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 <.001), whereas arterial carbon dioxide tension (37 ± 5 mm Hg vs. 41 ± 2 mm Hg; p <.05) and middle cerebral artery mean...

  7. Cerebral autoregulation dynamics in endurance-trained individuals

    DEFF Research Database (Denmark)

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

    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...... 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...... ± 4 mmHg, -26%) and MCA V(mean) (53 ± 3 to 37 ± 2 cm/s, -30%, vs. 58 ± 3 to 43 ± 2 cm/s, -25%). The athletes also had a slower recovery to baseline of both MAP (25 ± 2 vs. 16 ± 1 s, P <0.01) and MCA V(mean) (15 ± 1 vs. 11 ± 1 s, P <0.05). The onset of autoregulation, determined by the time point of...

  8. Dynamic cerebral autoregulation during repeated squat-stand maneuvers.

    NARCIS (Netherlands)

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

    2009-01-01

    Transfer function analysis of spontaneous oscillations in blood pressure (BP) and cerebral blood flow (CBF) can quantify the dynamic relationship between BP and CBF. However, such oscillation amplitudes are often small and of questionable clinical significance, vary substantially, and cannot be cont

  9. The sit-to-stand technique for the measurement of dynamic cerebral autoregulation.

    Science.gov (United States)

    Sorond, Farzaneh A; Serrador, Jorge M; Jones, Richard N; Shaffer, Michele L; Lipsitz, Lewis A

    2009-01-01

    Measurement of cerebral autoregulation is important for the evaluation and management of a number of clinical disorders that affect cerebral blood flow. We currently lack simple bedside measures that mimic common physiologic stresses. Therefore, we evaluated a new sit-to-stand technique as an alternative method to the frequently-used thigh-cuff technique in healthy volunteers. Continuous middle cerebral artery (MCA) blood flow velocities (BFV) and arterial blood pressure (ABP) were measured in response to standing from a sitting position, or rapid thigh-cuff deflation in 24 healthy subjects (50 +/- 22 y). Autoregulatory index (ARI) was calculated as the BFV response for step changes in ABP using a second-order differential equation with a set of parameters that can be used to grade the performance of autoregulation. Of these 24 subjects, 30% could tolerate only two thigh-cuffs and refused to proceed with the third cuff, whereas none of our subjects had any difficulty with performing the three sit-to-stand trials. The two techniques produced similar changes in mean ABP, but the times to nadir of the blood pressure and BFV were significantly faster for the thigh-cuff. The mean group ARIs were similar between the two techniques. Although between-subjects variability was higher for sit-to-stand ARIs, the within-subject sit-to-stand ARI variability was small. Thus, for the assessment of cerebral autoregulation, the sit-to-stand procedure is well tolerated and produces ARI values that have low within-subject variability. The sit-to-stand technique appears to be a suitable measure of individual ARI values for inferring dynamic cerebral autoregulation. PMID:18834658

  10. Effects of cerebral ischemia on human neurovascular coupling, CO2 reactivity, and dynamic cerebral autoregulation.

    Science.gov (United States)

    Salinet, Angela S M; Robinson, Thompson G; Panerai, Ronney B

    2015-01-15

    Cerebral blood flow (CBF) regulation can be impaired in acute ischemic stroke but the combined effects of dynamic cerebral autoregulation (CA), CO2 cerebrovascular reactivity (CVR), and neurovascular coupling (NVC), obtained from simultaneous measurements, have not been described. CBF velocity in the middle cerebral artery (MCA) (CBFv, transcranial Doppler), blood pressure (BP, Finometer), and end-tidal Pco2 (PetCO2 , infrared capnography) were recorded during a 1-min passive movement of the arm in 27 healthy controls [mean age (SD) 61.4 (6.0) yr] and 27 acute stroke patients [age 63 (11.7) yr]. A multivariate autoregressive-moving average model was used to separate the contributions of BP, arterial Pco2 (PaCO2 ), and the neural activation to the CBFv responses. CBFv step responses for the BP, CO2, and stimulus inputs were also obtained. The contribution of the stimulus to the CBFv response was highly significant for the difference between the affected side [area under the curve (AUC) 104.5 (4.5)%] and controls [AUC 106.9 (4.3)%; P = 0.008]. CBFv step responses to CO2 [affected hemisphere 0.39 (0.7), unaffected 0.55 (0.8), controls 1.39 (0.9)%/mmHg; P = 0.01, affected vs. controls; P = 0.025, unaffected vs. controls] and motor stimulus inputs [affected hemisphere 0.20 (0.1), unaffected 0.22 (0.2), controls 0.37 (0.2) arbitrary units; P = 0.009, affected vs. controls; P = 0.02, unaffected vs. controls] were reduced in the stroke group compared with controls. The CBFv step responses to the BP input at baseline and during the paradigm were not different between groups (P = 0.07), but PetCO2 was lower in the stroke group (P < 0.05). These results provide new insights into the interaction of CA, CVR, and NVC in both health and disease states. PMID:25593216

  11. The Sit-to-Stand Technique for the Measurement of Dynamic Cerebral Autoregulation

    OpenAIRE

    Sorond, Farzaneh A.; Serrador, Jorge M; Jones, Richard N; Michele L. Shaffer; Lipsitz, Lewis A.

    2008-01-01

    Measurement of cerebral autoregulation is important for the evaluation and management of a number of clinical disorders that affect cerebral blood flow. We currently lack simple bedside measures that mimic common physiologic stresses. Therefore, we evaluated a new sit-to-stand technique as an alternative method to the frequently used thigh-cuff technique in healthy volunteers. Continuous middle cerebral artery (MCA) blood flow velocities (BFV) and arterial blood pressure (ABP) were measured i...

  12. Continuous estimates of dynamic cerebral autoregulation: influence of non-invasive arterial blood pressure measurements

    International Nuclear Information System (INIS)

    Temporal variability of parameters which describe dynamic cerebral autoregulation (CA), usually quantified by the short-term relationship between arterial blood pressure (BP) and cerebral blood flow velocity (CBFV), could result from continuous adjustments in physiological regulatory mechanisms or could be the result of artefacts in methods of measurement, such as the use of non-invasive measurements of BP in the finger. In 27 subjects (61 ± 11 years old) undergoing coronary artery angioplasty, BP was continuously recorded at rest with the Finapres device and in the ascending aorta (Millar catheter, BPAO), together with bilateral transcranial Doppler ultrasound in the middle cerebral artery, surface ECG and transcutaneous CO2. Dynamic CA was expressed by the autoregulation index (ARI), ranging from 0 (absence of CA) to 9 (best CA). Time-varying, continuous estimates of ARI (ARI(t)) were obtained with an autoregressive moving-average (ARMA) model applied to a 60 s sliding data window. No significant differences were observed in the accuracy and precision of ARI(t) between estimates derived from the Finapres and BPAO. Highly significant correlations were obtained between ARI(t) estimates from the right and left middle cerebral artery (MCA) (Finapres r = 0.60 ± 0.20; BPAO r = 0.56 ± 0.22) and also between the ARI(t) estimates from the Finapres and BPAO (right MCA r = 0.70 ± 0.22; left MCA r = 0.74 ± 0.22). Surrogate data showed that ARI(t) was highly sensitive to the presence of noise in the CBFV signal, with both the bias and dispersion of estimates increasing for lower values of ARI(t). This effect could explain the sudden drops of ARI(t) to zero as reported previously. Simulated sudden changes in ARI(t) can be detected by the Finapres, but the bias and variability of estimates also increase for lower values of ARI. In summary, the Finapres does not distort time-varying estimates of dynamic CA obtained with a sliding window combined with an ARMA model, but

  13. Multimodal pressure-flow method to assess dynamics of cerebral autoregulation in stroke and hypertension

    Directory of Open Access Journals (Sweden)

    Lipsitz Lewis A

    2004-10-01

    Full Text Available Abstract Background This study evaluated the effects of stroke on regulation of cerebral blood flow in response to fluctuations in systemic blood pressure (BP. The autoregulatory dynamics are difficult to assess because of the nonstationarity and nonlinearity of the component signals. Methods We studied 15 normotensive, 20 hypertensive and 15 minor stroke subjects (48.0 ± 1.3 years. BP and blood flow velocities (BFV from middle cerebral arteries (MCA were measured during the Valsalva maneuver (VM using transcranial Doppler ultrasound. Results A new technique, multimodal pressure-flow analysis (MMPF, was implemented to analyze these short, nonstationary signals. MMPF analysis decomposes complex BP and BFV signals into multiple empirical modes, representing their instantaneous frequency-amplitude modulation. The empirical mode corresponding to the VM BP profile was used to construct the continuous phase diagram and to identify the minimum and maximum values from the residual BP (BPR and BFV (BFVR signals. The BP-BFV phase shift was calculated as the difference between the phase corresponding to the BPR and BFVR minimum (maximum values. BP-BFV phase shifts were significantly different between groups. In the normotensive group, the BFVR minimum and maximum preceded the BPR minimum and maximum, respectively, leading to large positive values of BP-BFV shifts. Conclusion In the stroke and hypertensive groups, the resulting BP-BFV phase shift was significantly smaller compared to the normotensive group. A standard autoregulation index did not differentiate the groups. The MMPF method enables evaluation of autoregulatory dynamics based on instantaneous BP-BFV phase analysis. Regulation of BP-BFV dynamics is altered with hypertension and after stroke, rendering blood flow dependent on blood pressure.

  14. Is dynamic cerebral autoregulation measurement using transcranial Doppler ultrasound reproducible in the presence of high concentration oxygen and carbon dioxide?

    Science.gov (United States)

    Minhas, Jatinder S; Syed, Nazia F; Haunton, Victoria J; Panerai, Ronney B; Robinson, Thompson G; Mistri, Amit K

    2016-05-01

    Reliability of cerebral blood flow velocity (CBFV) and dynamic cerebral autoregulation estimates (expressed as autoregulation index: ARI) using spontaneous fluctuations in blood pressure (BP) has been demonstrated. However, reliability during co-administration of O2 and CO2 is unknown. Bilateral CBFV (using transcranial Doppler), BP and RR interval recordings were performed in healthy volunteers (seven males, four females, age: 54  ±  10 years) on two occasions over 9  ±  4 d. Four 5 min recordings were made whilst breathing air (A), then 5%CO2 (C), 80%O2 (O) and mixed O2  +  CO2 (M), in random order. CBFV was recorded; ARI was calculated using transfer function analysis. Precision was quantified as within-visit standard error of measurement (SEM) and the coefficient of variation (CV). CBFV and ARI estimates with A (SEM: 3.85 & 0.87; CV: 7.5% & 17.8%, respectively) were comparable to a previous reproducibility study. The SEM and CV with C and O were similar, though higher values were noted with M; Bland-Altman plots indicated no significant bias across all gases for CBFV and ARI (bias  Doppler-ultrasound-estimated CBFV and ARI during inhalation of O2 and CO2 have acceptable levels of reproducibility and can be used to study the effect of these gases on cerebral haemodynamics. PMID:27093290

  15. 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

    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......(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...... MCAv, S100beta and neuron-specific enolase. In conclusion, these findings suggest that AMS is associated with altered redox homeostasis and disordered CA independent of barrier disruption....

  16. Random perturbations of arterial blood pressure for the assessment of dynamic cerebral autoregulation

    International Nuclear Information System (INIS)

    The assessment of cerebral autoregulation (CA) relies mostly on methods that modulate arterial blood pressure (ABP). Despite advances, the gold standard of assessment remains elusive and clinical practicality is limited. We investigate a novel approach of assessing CA, consisting of the intermittent application of thigh cuffs using square wave sequences. Our aim was to increase ABP variability whilst minimizing volunteer discomfort, thus improving assessment acceptability. Two random square wave sequences and two maximum pressure settings (80 and 150 mmHg) were used, corresponding to four manoeuvres that were conducted in random order after a baseline recording. The intermittent application of thigh cuffs resulted in an amplitude dependent increase in ABP (p = 0.001) and cerebral blood flow velocity (CBFV) variability (p = 0.026) compared to baseline. No statistically significant differences in mean heart rate or heart rate variability were observed (p = 0.108 and p = 0.350, respectively), suggesting that no significant sympathetic response was elicited. No significant differences in the CBFV step response were observed, suggesting no distortion of autoregulatory parameters resulted from the use of thigh cuffs. We conclude that pseudorandom binary sequences are an effective and safe alternative for increasing ABP variability. This new approach shows great promise as a tool for the robust assessment of CA. (paper)

  17. Dynamic cerebral autoregulation and cerebrovascular reactivity: a comparative study in lacunar infarct patients

    International Nuclear Information System (INIS)

    The major purpose of this study was to simultaneously evaluate dCA before and shortly after cerebral vasodilatation evoked by infusion of acetazolamide (ACZ). It was questioned if and to what degree dCA was changed after ACZ infusion. Using 15 mg kg−1 ACZ infusion cerebrovascular reactivity (CVR) was assessed in 29 first ever lacunar stroke patients (19 M/10 F). During the CVR-test, the electrocardiogram, non-invasive finger arterial blood pressure (ABP) and middle cerebral artery blood flow velocity (CBFV) were recorded. DCA based on spontaneous blood pressure variations was evaluated in 24 subjects by linear transfer function analysis. Squared coherence, gain and phase angle in the frequency range of autoregulation (0.04–0.16 Hz) were compared before and after ACZ infusion. After ACZ infusion, median phase angle decreased significantly (p < 0.005 Wilcoxon) to 0.77 rad compared to a pre-test baseline value of 1.05 rad, indicating less efficient dCA due to ACZ. However, post-test phase values are still mostly within the normal range. Poor and statistically non-significant correlations were found between CVR and absolute dCA phase angle. It can be concluded that CVR testing with body weight adjusted infusion of ACZ lowers dCA performance but by no means exhausts dCA, suggesting that in this way maximal CVR is not determined. Characterizing dCA based on transfer function analysis of ABP to CBFV needs no provocation and adverse patient effects are minimal. The poor correlation between CVR and dCA phase angle supports an interpretation that CVR and dCA study different mechanisms of cerebrovascular control

  18. Cerebral Blood Flow Autoregulation and Dysautoregulation.

    Science.gov (United States)

    Armstead, William M

    2016-09-01

    This article provides a review of cerebral autoregulation, particularly as it relates to the clinician scientist experienced in neuroscience in anesthesia and critical care. Topics covered are biological mechanisms; methods used for assessment of autoregulation; effects of anesthetics; role in control of cerebral hemodynamics in health and disease; and emerging areas, such as role of age and sex in contribution to dysautoregulation. Emphasis is placed on bidirectional translational research wherein the clinical informs the study design of basic science studies, which, in turn, informs the clinical to result in development of improved therapies for treatment of central nervous system conditions. PMID:27521192

  19. 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...

  20. [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. Thereby...

  1. 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

  2. Cerebral autoregulation in the first day after preterm birth

    DEFF Research Database (Denmark)

    Hahn, Gitte Holst; Maroun, Lisa Leth; Larsen, Nanna;

    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....

  3. 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, fronta...

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

    International Nuclear Information System (INIS)

    Cerebral autoregulation has been studied by linear filter systems, with arterial blood pressure (ABP) as the input and cerebral blood flow velocity (CBFV—from transcranial Doppler Ultrasound) as the output. The current work extends this by using adaptive filters to investigate the dynamics of time-varying cerebral autoregulation during step-wise changes in arterial PaCO2. Cerebral autoregulation was transiently impaired in 11 normal adult volunteers, by switching inspiratory air to a CO2/air mixture (5% CO2, 30% O2 and 65% N2) for approximately 2 min and then back to the ambient air, causing step-wise changes in end-tidal CO2 (EtCO2). Simultaneously, ABP and CBFV were recorded continuously. Simulated data corresponding to the same protocol were also generated using an established physiological model, in order to refine the signal analysis methods. Autoregulation was quantified by the time-varying phase lead, estimated from the adaptive filter model. The adaptive filter was able to follow rapid changes in autoregulation, as was confirmed in the simulated data. In the recorded signals, there was a slow decrease in autoregulatory function following the step-wise increase in PaCO2 (but this did not reach a steady state within approximately 2 min of recording), with a more rapid change in autoregulation on return to normocapnia. Adaptive filter modelling was thus able to demonstrate time-varying autoregulation. It was further noted that impairment and recovery of autoregulation during transient increases in EtCO2 occur in an asymmetric manner, which should be taken into account when designing experimental protocols for the study of autoregulation

  5. 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.

  6. Intraaortic Balloon Pump Counterpulsation and Cerebral Autoregulation: an observational study

    OpenAIRE

    Boots Rob; Barnett Adrian G; Timms Daniel; Dunster Kimble; Geng Shureng; Bellapart Judith; Fraser John F

    2010-01-01

    Abstract Background The use of Intra-aortic counterpulsation is a well established supportive therapy for patients in cardiac failure or after cardiac surgery. Blood pressure variations induced by counterpulsation are transmitted to the cerebral arteries, challenging cerebral autoregulatory mechanisms in order to maintain a stable cerebral blood flow. This study aims to assess the effects on cerebral autoregulation and variability of cerebral blood flow due to intra-aortic balloon pump and in...

  7. 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...

  8. Cerebral Blood Flow and Autoregulation after Pediatric Traumatic Brain Injury

    OpenAIRE

    Udomphorn, Yuthana; Armstead, William M.; Vavilala, Monica S.

    2008-01-01

    Traumatic brain injury is a global health concern and is the leading cause of traumatic morbidity and mortality in children. Despite a lower overall mortality than in adult traumatic brain injury, the cost to society from the sequelae of pediatric traumatic brain injury is very high. Predictors of poor outcome after traumatic brain injury include altered systemic and cerebral physiology, including altered cerebral hemodynamics. Cerebral autoregulation is often impaired following traumatic bra...

  9. In vivo cerebral blood flow autoregulation studies using rheoencephalography

    Science.gov (United States)

    Bodo, M.; Pearce, F.; Garcia, A.; Van Albert, S.; Settle, T.; Szebeni, J.; Baranyi, L.; Hartings, J.; Armonda, R.

    2010-04-01

    Acute management of patients with traumatic brain/blast injury is a challenge. To minimize secondary injury and improve outcome, it is critical to detect neurological deterioration early, when it is potentially reversible. One potential monitoring method is cerebral electrical impedance (rheoencephalography-REG) because of its non-invasiveness and good time resolution. Reported here are the results of cerebral blood flow (CBF) manipulations comparing electroencephalogram (EEG) with REG (both intra-cerebral) and measuring with surface and skull REG electrodes. Our hypothesis was that REG would reflect spreading depression and CBF autoregulation. Animal experiments were performed using one rat (four trials with intracerebral electrodes), monkeys (n=8, with surface electrodes) and pigs (n = 24 pigs with skull electrodes; 57 trials, 19 types of liposomes). Challenges included intracranial pressure (ICP) elevation, liposome infusion, and hemorrhage. Data were stored on a PC and evaluated off line. CBF autoregulation was evaluated both by visual inspection and by a Matlab script. These studies confirmed that REG reflects CBF autoregulation and that REG is useful for detecting spreading depression (SD), vasospasm and the lower limit of CBF autoregulation. These findings have clinical relevance for use in noninvasive neuro-monitoring in the neurosurgery intensive care and during transportation of patients with brain injury.

  10. 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 og...... iskæmi under episoder med lavt MAP, og for cerebral hyperperfusion og vasogent ødem ved højt MAP. CBF autoregulationen undersøgtes hos tyve voksne patienter med akut bakteriel meningitis i den tidlige sygdomsfase (<24 timer efter diagnostisk lumbalpunktur). Idet autoregulationen fandtes svækket hos...... meningitis, men retableres ved klinisk restitution. Autoregulationen kan endvidere delvis retableres ved akut hyperventilation. Fundene har potentiel betydning for valg af supportiv terapi hos patienter med meningitis....

  11. Myogenic and metabolic feedback in cerebral autoregulation: Putative involvement of arachidonic acid-dependent pathways.

    Science.gov (United States)

    Berg, Ronan M G

    2016-07-01

    The present paper presents a mechanistic model of cerebral autoregulation, in which the dual effects of the arachidonic acid metabolites 20-hydroxyeicosatetraenoic acid (20-HETE) and epoxyeicosatrienoic acids (EETs) on vascular smooth muscle mediate the cerebrovascular adjustments to a change in cerebral perfusion pressure (CPP). 20-HETE signalling in vascular smooth muscle mediates myogenic feedback to changes in vessel wall stretch, which may be modulated by metabolic feedback through EETs released from astrocytes and endothelial cells in response to changes in brain tissue oxygen tension. The metabolic feedback pathway is much faster than 20-HETE-dependent myogenic feedback, and the former thus initiates the cerebral autoregulatory response, while myogenic feedback comprises a relatively slower mechanism that functions to set the basal cerebrovascular tone. Therefore, assessments of dynamic cerebral autoregulation, which may provide information on the response time of the cerebrovasculature, may specifically be used to yield information on metabolic feedback mechanisms, while data based on assessments of static cerebral autoregulation represent the integrated functionality of myogenic and metabolic feedback. PMID:27241246

  12. 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

  13. 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

    Using the arteriovenous oxygen difference method autoregulation of cerebral blood flow (CBF) was tested in 16 long-term diabetics and eight control patients. Blood pressure was raised by angiotensin infusion and lowered by trimethaphan camsylate infusion, in some cases combined with head-up tilting...... 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, indicating impaired autoregulation. The cause of impaired autoregulation in some long-term diabetics is believed to be diffuse or multifocal dysfunction of cerebral arterioles due to diabetic vascular disease. Other conditions with impaired autoregulation are discussed and compared with that seen...

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

    DEFF Research Database (Denmark)

    Eriksen, Vibeke R; Holst Hahn, Gitte; 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 frequen...

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

    DEFF Research Database (Denmark)

    Hahn, Gitte Holst

    2013-01-01

    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...... 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 with...... preterm infants and experimental studies in newborn piglets. Maintaining adequate cerebral perfusion is critical to avoid brain injury. In healthy neonates, cerebral autoregulation ensures an almost unchanged cerebral perfusion within a narrow range of arterial blood pressures. When autoregulation is...

  16. 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 was......PURPOSE: Blood pressure management in acute intracerebral hemorrhage (ICH) relies on functioning cerebral autoregulation. The time course of autoregulation in acute ICH and its relation with clinical outcome are not known. METHODS: Twenty-six patients with spontaneous ICH were studied on days 1, 3...... related with lower Glasgow coma score, ventricular hemorrhage (both sides) and lower noninvasive cerebral perfusion pressure (ipsilateral). Increasing ipsilateral Mx between days 3 and 5 was related with lower Glasgow coma score and ventricular hemorrhage. In a multivariate analysis controlling for other...

  17. 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...

  18. 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.

  19. 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

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

    Science.gov (United States)

    Riberholt, Christian Gunge; Olesen, Niels Damkjær; Thing, Mira; Juhl, Carsten Bogh; Mehlsen, Jesper; Petersen, Tue Hvass

    2016-01-01

    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. PMID:27168188

  1. The effect of Ventricular Assist Devices on cerebral autoregulation: A preliminary study

    Directory of Open Access Journals (Sweden)

    Dunster Kimble R

    2011-02-01

    Full Text Available Abstract Background The insertion of Ventricular Assist Devices is a common strategy for cardiovascular support in patients with refractory cardiogenic shock. This study sought to determine the impact of ventricular assist devices on the dynamic relationship between arterial blood pressure and cerebral blood flow velocity. Methods A sample of 5 patients supported with a pulsatile ventricular assist device was compared with 5 control patients. Controls were matched for age, co-morbidities, current diagnosis and cardiac output state, to cases. Beat-to-beat recordings of mean arterial pressure and cerebral blood flow velocity, using transcranial Doppler were obtained. Transfer function analysis was performed on the lowpass filtered pressure and flow signals, to assess gain, phase and coherence of the relationship between mean arterial blood pressure and cerebral blood flow velocity. These parameters were derived from the very low frequency (0.02-0.07 Hz, low frequency (0.07-0.2 Hz and high frequency (0.2-0.35 Hz. Results No significant difference was found in gain and phase values between the two groups, but the low frequency coherence was significantly higher in cases compared with controls (mean ± SD: 0.65 ± 0.16 vs 0.38 ± 0.19, P = 0.04. The two cases with highest coherence (~0.8 also had much higher spectral power in mean arterial blood pressure. Conclusions Pulsatile ventricular assist devices affect the coherence but not the gain or phase of the cerebral pressure-flow relationship in the low frequency range; thus whether there was any significant disruption of cerebral autoregulation mechanism was not exactly clear. The augmentation of input pressure fluctuations might contribute in part to the higher coherence observed.

  2. Evaluation of cerebral autoregulation by SPECT imaging during supine and standing positions

    International Nuclear Information System (INIS)

    We developed a new method for evaluating cerebral autoregulation using consecutive brain SPECT. Five patients with cerebral ischemia symptoms during postural changes (2 olivo-pontocerebellar atrophy, 1 multiple system atrophy, and 2 Parkinson's disease) and 5 normal controls without symptoms were studied. In a supine position, 740 MBq (20 mCi) of 99mTc-HMPAO was injected and the first acquisition was performed, lasting a total of 10 minutes. Soon after the end of the first scan, subjects were instructed to stand from the supine position. While standing, an additional 20 mCi of 99mTc-HMPAO was injected, and a second acquisition was commenced in the same position as the frist scan. Blood pressure in the supine and standing positions was recorded. The cerebral blood flow image in the standing position was obtained by subtracting the image in the first scan from that in the second. This method enabled us to perform the whole study within 40 minutes. A relative decrease in flow in the standing position was seen in each cerebral cortex in the patient, but not in controls. Dysautoregulation index (Δ% flow/mmHg) in patients was significantly high compared with that of controls, suggesting impairment of autoregulation of cerebral blood flow. In conclusion, our new SPECT technique is a simple and noninvasive method to evaluate cerebral autoregulation and can be applied in general practice. (author)

  3. 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

    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...... 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...

  4. Modelling Cerebrovascular Reactivity: A Novel Near-Infrared Biomarker of Cerebral Autoregulation?

    OpenAIRE

    Highton, D.; Panovska-Griffiths, J; Ghosh, A; Tachtsidis, I; Banaji, M.; Elwell, C.; Smith, M.

    2013-01-01

    Understanding changes in cerebral oxygenation, haemodynamics and metabolism holds the key to individualised, optimised therapy after acute brain injury. Near-infrared spectroscopy (NIRS) offers the potential for non-invasive, continuous bedside measurement of surrogates for these processes. Interest has grown in applying this technique to interpret cerebrovascular pressure reactivity (CVPR), a surrogate of the brain's ability to autoregulate blood flow. We describe a physiological model-based...

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

    OpenAIRE

    Riberholt, Christian Gunge; Olesen, Niels Damkjær; Thing, Mira; Juhl, Carsten Bogh; Mehlsen, Jesper; Petersen, Tue Hvass

    2016-01-01

    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 wa...

  6. Near-infrared spectroscopy for evaluation of cerebral autoregulation during orthotopic liver transplantation

    DEFF Research Database (Denmark)

    Nissen, P.; Pacino, H.; Frederiksen, H.J.;

    2009-01-01

    detected, S(c)O(2) varied in parallel with mean arterial pressure (MAP) for 3 patients and, therefore, an autoregulation curve could not be established and yet, there was detected no change in S(c)O(2) to a lowest MAP ranging from 42 to 66 mmHg for 20 patients, while for 8 patients a decrease in S(c)O(2......) was detected at a MAP of 69 (50-90) mmHg; (median and range). As detected by NIRS, the present study confirms that some patients undergoing liver transplantation do not demonstrate cerebral autoregulation but for the majority of the patients, S(c)O(2) was stable over a wide range of MAP suggesting......INTRODUCTION: The present study evaluated whether frontal lobe cerebral oxygenation (S(c)O(2)), as assessed by near-infrared spectroscopy (NIRS), can detect cerebral autoregulation in patients undergoing orthotopic liver transplantation. METHODS: We studied changes in frontal lobe S(c)O(2) assessed...

  7. 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

    during incremental reductions in cerebral perfusion pressure (CPP) by controlled hemorrhage. Autoregulation was preserved in all rats without meningitis (groups A and E) and was lost in 24 of 25 meningitis rats (groups B, C, and D) (P<0.01). In group A, the lower limit was higher than that of group E (P......<0.05). The slope of the CBF/CPP regression line differed between the meningitis groups (P<0.001), being steeper for group B than groups C and D, with no difference between these two groups. The results suggest that pneumococcal bacteremia in rats triggers cerebral vasodilation, which right shifts...

  8. Statistical criteria for estimation of the cerebral autoregulation index (ARI) at rest.

    Science.gov (United States)

    Panerai, R B; Haunton, V J; Hanby, M F; Salinet, A S M; Robinson, T G

    2016-05-01

    The autoregulation index (ARI) can reflect the effectiveness of cerebral blood flow (CBF) control in response to dynamic changes in arterial blood pressure (BP), but objective criteria for its validation have not been proposed. Monte Carlo simulations were performed by generating 5 min long random input/output signals that mimic the properties of mean beat-to-beat BP and CBF velocity (CBFV) as usually obtained by non-invasive measurements in the finger (Finometer) and middle cerebral artery (transcranial Doppler ultrasound), respectively. Transfer function analysis (TFA) was used to estimate values of ARI by optimal fitting of template curves to the output (or CBFV) response to a step change in input (or BP). Two-step criteria were adopted to accept estimates of ARI as valid. The 95% confidence limit of the mean coherence function (0.15-0.25 Hz) ([Formula: see text]) was estimated from 15 000 runs, resulting in [Formula: see text]  =  0.190 when using five segments of data, each with 102.4 s (512 samples) duration (Welch's method). This threshold for acceptance was dependent on the TFA settings and increased when using segments with shorter duration (51.2 s). For signals with mean coherence above the critical value, the 5% confidence limit of the normalised mean square error (NMSEcrit) for fitting the step response to Tieck's model, was found to be approximately 0.30 and independent of the TFA settings. Application of these criteria to physiological and clinical sets of data showed their ability to identify conditions where ARI estimates should be rejected, for example due to CBFV step responses lacking physiological plausibility. A larger number of recordings were rejected from acute ischaemic stroke patients than for healthy volunteers. More work is needed to validate this procedure with different physiological conditions and/or patient groups. The influence of non-stationarity in BP and CBFV signals should also be investigated. PMID:27093173

  9. 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

    Sepsis is frequently complicated by brain dysfunction, which may be associated with disturbances in cerebral autoregulation rendering the brain susceptible to hypo- and hyperperfusion. The purpose of the present study was to assess static and dynamic cerebral autoregulation (i) in a human-experim...

  10. 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...... administered recombinant EPO on impaired cerebral blood flow (CBF) autoregulation after experimental subarachnoid haemorrhage (SAH). Four groups of male Sprague-Dawley rats were studied: group A, sham operation plus vehicle; group B, sham operation plus EPO; group C, SAH plus vehicle; group D, SAH plus EPO...

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

    International Nuclear Information System (INIS)

    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.

  12. 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.

  13. 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; Greisen, G

    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....... 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...

  14. Dynamic autoregulation and renal injury in Dahl rats

    DEFF Research Database (Denmark)

    Karlsen, F M; Andersen, C B; Leyssac, P P; Holstein-Rathlou, N H

    1997-01-01

    The Dahl salt-sensitive (Dahl S) rat develops hypertension and renal injuries when challenged with a high salt diet and has been considered to be a model of chronic renal failure. Renal injuries appear very early in life compared with the spontaneously hypertensive rat (SHR). During the course of...... hypertension, a gradual impairment of autoregulatory control of renal blood flow might expose the glomerular circulation to periods of elevated pressure, resulting in renal injuries in Dahl S rats. Dynamic autoregulatory capacity was assessed in Dahl S and Dahl salt-resistant (Dahl R) rats, SHR, and Sprague......-Dawley rats by inducing broad-band fluctuations in the arterial blood pressure and simultaneously measuring renal blood flow. Dynamic autoregulation was estimated by the transfer function using blood pressure as the input and renal blood flow as the output. Renal morphological injuries were evaluated in Dahl...

  15. 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......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...... in similar results. We conclude that even though LDF overestimated CBF during haemorrhagic shock caused by controlled haemorrhage, the lower limit autoregulation was correctly identified. The laser Doppler technique provides a reliable method for detection of a wide range of cerebral blood flow changes under...... CO2 challenge. Haemodilution influences the two methods differently causing relative overestimation of blood flow by the laser Doppler technique compared to the 133xenon method....

  16. 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.

  17. 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...... and the steady-state cerebrovascular response to postural change were studied in subjects with DM+ and DM-, in the absence of cardiovascular autonomic neuropathy, and in CTRL (healthy control) subjects. The relationship between spontaneous changes in MCA V(mean) (middle cerebral artery mean blood...

  18. 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. PMID:26935320

  19. The carotid artery as an alternative site for dynamic autoregulation measurement: an inter-observer reproducibility study.

    Science.gov (United States)

    Nogueira, R C; Saeed, N P; Bor-Seng-Shu, E; Teixeira, M J; Robinson, T G; Panerai, R B

    2016-07-01

    The internal carotid artery (ICA) has been proposed as an alternative site to the middle cerebral artery (MCA) to measure dynamic cerebral autoregulation (dCA) using transcranial Doppler ultrasound (TCD). Our aim was to test the inter-operator reproducibility of dCA assessment in the ICA and the effect of interaction amongst different variables (artery source × operator × intra-subject variability). Two operators measured blood flow velocity using TCD at the ICA and MCA simultaneously on each side in 12 healthy volunteers. The autoregulation index (ARI) was estimated by transfer function analysis. A two-way repeated measurements ANOVA with post-hoc Tukey tested the difference between ARI by different operators and interaction effects were analysed based on the generalized linear model. In this healthy population, no significant differences between operator and no interaction effects were identified amongst the different variables. This study reinforced the validity of using the ICA as an alternative site for the assessment of dCA. Further work is needed to confirm and extend our findings, particularly to disease populations. PMID:27134150

  20. 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; Greisen, Gorm

    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...... 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....

  1. A dynamic model of renal blood flow autoregulation

    DEFF Research Database (Denmark)

    Holstein-Rathlou, N H; Marsh, D J

    1994-01-01

    of renal autoregulation, a broad band perturbation of the arterial pressure was employed in both the simulations and the experiments. Renal blood flow and tubular pressure were used as response variables in the comparison. To better approximate the situation in vivo where a large number of individual...... 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...

  2. Cerebral autoregulation is minimally influenced by the superior cervical ganglion in two- week-old lambs, and absent in preterm lambs immediately following delivery.

    Directory of Open Access Journals (Sweden)

    Adam J Czynski

    Full Text Available Cerebral vessels in the premature newborn brain are well supplied with adrenergic nerves, stemming from the superior cervical ganglia (SCG, but their role in regulation of blood flow remains uncertain. To test this function twelve premature or two-week-old lambs were instrumented with laser Doppler flow probes in the parietal cortices to measure changes in blood flow during changes in systemic blood pressure and electrical stimulation of the SCG. In lambs delivered prematurely at ∼129 days gestation cerebral perfusion and driving pressure demonstrated a direct linear relationship throughout the physiologic range, indicating lack of autoregulation. In contrast, in lambs two-weeks of age, surgical removal of one SCG resulted in ipsilateral loss of autoregulation during pronounced hypertension. Electrical stimulation of one SCG elicited unilateral increases in cerebral resistance to blood flow in both pre-term and two-week-old lambs, indicating functioning neural pathways in the instrumented, anesthetized lambs. We conclude cerebral autoregulation is non-functional in preterm lambs following cesarean delivery. Adrenergic control of cerebral vascular resistance becomes effective in newborn lambs within two-weeks after birth but SCG-dependent autoregulation is essential only during pronounced hypertension, well above the normal range of blood pressure.

  3. Utilization of Superfused Cerebral Slices in Probing Muscarinic Receptor Autoregulation of Acetylcholine Release

    Czech Academy of Sciences Publication Activity Database

    Alquicer, Glenda; Doležal, Vladimír; El-Fakahany, E. E.

    New York: Springer, 2016 - (Mysliveček, J.; Jakubík, J.), s. 221-233. (Neuromethods. 107). ISBN 978-1-4939-2857-6 R&D Projects: GA ČR(CZ) GA14-05696S; GA MŠk(CZ) EE2.3.30.0025 Institutional support: RVO:67985823 Keywords : muscarinic receptors * acetylcholine release * autoregulation * superfusion Subject RIV: FH - Neurology

  4. 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

    Autoregulation of cerebral blood flow, i.e., the maintenance of cerebral blood flow within narrow limits during changes in arterial perfusion pressure, was studied in nine healthy control subjects and in 12 long-term Type I (insulin-dependent) diabetic patients with clinical microangiopathy....... 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...

  5. Dynamic cerebral autoregulatory capacity is affected early in type 2 diabetes mellitus

    OpenAIRE

    Kim, Yu-Sok; Immink, Rogier V.; Stok, Wim J.; Karemaker, John M.; Secher, Niels H; van Lieshout, Johannes J.

    2008-01-01

    Abstract 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. We tested the hypothesis that in absence of cardiovascular autonomic neuropathy, cerebral autoregulation is impaired in subjects with type 2 diabetes with microvascular complications but intact in subjects withou...

  6. Nonlinear analysis of renal autoregulation in rats using principal dynamic modes

    DEFF Research Database (Denmark)

    Marmarelis, V Z; Chon, K H; Holstein-Rathlou, N H; Marsh, D J

    1999-01-01

    This article presents results of the use of a novel methodology employing principal dynamic modes (PDM) for modeling the nonlinear dynamics of renal autoregulation in rats. The analyzed experimental data are broadband (0-0.5 Hz) blood pressure-flow data generated by pseudorandom forcing and...... collected in normotensive and hypertensive rats for two levels of pressure forcing (as measured by the standard deviation of the pressure fluctuation). The PDMs are computed from first-order and second-order kernel estimates obtained from the data via the Laguerre expansion technique. The results...... to the tubuloglomerular feedback (TGF) mechanism. This allows the study of the separate contributions of the two mechanisms to the autoregulatory response dynamics, as well as the effects of the level of pressure forcing and hypertension on the two distinct autoregulatory mechanisms. It is shown that...

  7. 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......) had CBF values of about 40 ml/100 gm/minute. Hypotensive infants with asphyxia at birth or RDS or both had values for CBF of about 20 ml/100 gm/minute, or less. CBF was strongly correlated with the arterial blood pressure, showing a linear relationship that was identical in infants with asphyxia at...

  8. 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.

  9. Vortex Dynamics in Cerebral Aneurysms

    CERN Document Server

    Byrne, Greg

    2013-01-01

    We use an autonomous three-dimensional dynamical system to study embedded vortex structures that are observed to form in computational fluid dynamic simulations of patient-specific cerebral aneurysm geometries. These structures, described by a vortex which is enclosed within a larger vortex flowing in the opposite direction, are created and destroyed in phase space as fixed points undergo saddle-node bifurcations along vortex core lines. We illustrate how saddle-node bifurcations along vortex core lines also govern the formation and evolution of embedded vortices in cerebral aneurysms under variable inflow rates during the cardiac cycle.

  10. 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...... arterial pressure to RBF in the frequency domain was used to examine the myogenic response (MR; 0.06-0.09 Hz) and the tubuloglomerular feedback mechanism (TGF; 0.03-0.06 Hz). MAP was elevated in ANG II-infused rats compared with sham groups (P <0.05). RBF in ANG II HNa was reduced vs. sham NNa and sham HNa...... sham HNa). Gain values in the frequency range of the MR and TGF were significantly reduced by tempol in ANG II-infused rats on HNa diet. In summary, the MR and TGF components of RBF autoregulation were impaired in ANG II HNa, and these abnormalities were attenuated by tempol, suggesting a pathogenetic...

  11. Cerebral autoregulation and flow/metabolism coupling during cardiopulmonary bypass: the influence of PaCO2

    International Nuclear Information System (INIS)

    Measurement of 133Xe 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 PaCO2 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 PaCO2 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

  12. 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.

  13. 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...... survivors. The analogy was hypertensive hemorrhagic stroke in the adult. Cerebral hemorrhage was perceived as the major (preventable) cause of brain injury in the preterm baby. An immature cerebral autoregulation or a vulnerability of the autoregulation exposed by preceding hypoxia or ischemia therefore...

  14. 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...... increase the susceptibility to hypertensive end-organ injury and progressive renal failure by facilitating pressure transmission to the microvasculature....... 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...

  15. 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.

  16. The effect of an acute increase in central blood volume on the response of cerebral blood flow to acute hypotension.

    Science.gov (United States)

    Ogoh, Shigehiko; Hirasawa, Ai; Sugawara, Jun; Nakahara, Hidehiro; Ueda, Shinya; Shoemaker, J Kevin; Miyamoto, Tadayoshi

    2015-09-01

    The purpose of the present study was to examine whether the response of cerebral blood flow to an acute change in perfusion pressure is modified by an acute increase in central blood volume. Nine young, healthy subjects voluntarily participated in this study. To measure dynamic cerebral autoregulation during normocapnic and hypercapnic (5%) conditions, the change in middle cerebral artery mean blood flow velocity was analyzed during acute hypotension caused by two methods: 1) thigh-cuff occlusion release (without change in central blood volume); and 2) during the recovery phase immediately following release of lower body negative pressure (LBNP; -50 mmHg) that initiated an acute increase in central blood volume. In the thigh-cuff occlusion release protocol, as expected, hypercapnia decreased the rate of regulation, as an index of dynamic cerebral autoregulation (0.236 ± 0.018 and 0.167 ± 0.025 s(-1), P = 0.024). Compared with the cuff-occlusion release, the acute increase in central blood volume (relative to the LBNP condition) with LBNP release attenuated dynamic cerebral autoregulation (P = 0.009). Therefore, the hypercapnia-induced attenuation of dynamic cerebral autoregulation was not observed in the LBNP release protocol (P = 0.574). These findings suggest that an acute change in systemic blood distribution modifies dynamic cerebral autoregulation during acute hypotension. PMID:26159757

  17. Lesions of nucleus tractus solitarii globally impair cerebrovascular autoregulation

    International Nuclear Information System (INIS)

    The authors studied the effects of acute bilateral electrolytic lesions of the nucleus tractus solitarii (NTS) on regional cerebral blood flow (rCBF) and its autoregulation in rats anesthetized, paralyzed, and artificially ventilated. rCBF or regional cerebral glucose utilization (rCGU) was measured 30 min after NTS lesions, by the 14C-iodoantipyrine technique or 2-deoxyglucose method, respectively. Cerebrovascular autoregulation was assessed in groups of 4-5 rats at three levels of arterial pressure (AP):90, 125, and 140 mmHg. AP was lowered by hemorrhage or elevated by intravenous infusion of phenylephrine. NTS lesions did not alter rCBF at 125 mmHg but resulted in loss of autoregulation. In contrast, lesions of the cuneate nucleus or transection of the baroreceptor afferents did not alter autoregulation. NTS lesions did not affect the reactivity of the cerebrovascular bed to hypercarbia or hypocarbia nor the rCGU in any brain regions. They conclude that lesions of the NTS impair cerebrovascular autoregulation. The effect is not due to changes in metabolism, nonspecific effects of the lesions, vasoparalysis, or interruption of the baroreceptor reflex arch. Neural pathways originating in or passing through the NTS can regulate the cerebrovascular autoregulation of the entire brain

  18. Dynamic CT scan in cerebral infarction

    International Nuclear Information System (INIS)

    Forty-two dynamic CT studies were performed on 27 patients with cerebral infarction (11 to 75 years of age), and perfusion patterns of low density areas on plain CT were evaluated. The initial studies were performed 1.5 hours to 60 days after acute onset. The following results were obtained. 1) The perfusion pattern in the low density area on plain CT varies among patients at any periods after onset, ranging from absent perfusion pattern to hyperfusion pattern. No consisitent perfusion pattern was obtained at any given time after onset. 2) Repeat dynamic CT revealed that the perfusion pattern in the low density area changed with time variously. 3) The perfusion pattern or change of perfusion pattern did not correlate with outcome of the patient. 4) At an acute stage, when no abnormal findings were obtained on plain CT, dynamic CT revealed abnormal perfusion pattern, enabling early diagnosis of cerebral infarction and estimation of blood perfusion in the infarcted area. In determining the treatment for the cerebral infarction at an acute stage, it is important to know the condition of the blood perfusion in the infarcted area. For the patients in whom recanalization has already taken place, mannitol or steroid might be effective, providing protection against severe brain edema and hemorrhagic infarction. On the other hand, if recanalization has not taken place, revascularization therapy might be worth trying within 6 hours since the onset. It has been said that ischemic brain damage may not be reversed by the revascularization after 6 hours. Dynamic CT is safe, less invasive, convenient and very useful for early diagnosis of the cerebral infarction and determination of the treatment at the acute stage. (J.P.N.)

  19. Dynamic exercise enhances regional cerebral artery mean flow velocity

    DEFF Research Database (Denmark)

    Linkis, P; Jørgensen, L G; Olesen, H L;

    1995-01-01

    Dynamic exercise enhances regional cerebral artery mean flow velocity. J. Appl. Physiol. 78(1): 12-16, 1995.--Anterior (ACA) and middle (MCA) cerebral artery mean flow velocities (Vmean) and pulsatility indexes were determined using transcranial Doppler in 14 subjects during dynamic exercise afte...

  20. Dynamic CT scan in cerebral infarction

    International Nuclear Information System (INIS)

    62 Dynamic CT studies were performed on 40 patients with cerebral infarction (11 to 75 years of age), and the perfusion patterns of low-density areas on plain CT were evaluated. The examinations were performed 1.5 hours to 60 days after acute onset. The procedures were as follows: 65 % amidotrizomeglumin (1 ml/kg) was injected upon the initiation of the second scanning over 5 seconds through an 18 G needle placed in the antecubital vein. A total of 8 and 10 serial high-speed scans were performed with the SOMATOM 2 and CT/T 8800 apparatuses respectively. The perfusion pattern was evaluated by comparing the two time-density curves obtained from the infarcted area and the same region on the contralateral side. The following results were obtained: 1) The perfusion patterns of the infarcted area may be classified into 5 groups: ''absent,'' ''hypo,'' ''normal,'' ''hyper,'' and ''absent + late'' perfusion patterns. 2) In most cases, a dynamic CT reveals absent perfusion pattern at the acute stage in the infarcted area when no abnormal findings are obtained on plain CT. 3) Repeat dynamic CT revealed that the perfusion pattern varied with the time, and in some cases we could know the development of the hemorrhagic infarction in advance. 4) The perfusion pattern or change in the perfusion pattern did not correlate with the outcome of the patient. For the patients in whom recanalization has already taken place, the main point of treatment is to protect the brain against severe brain edema and hemorrhagic infarction. On the other hand, if recanalization has not yet taken place, revascularization therapy might be worth trying unless 6 hours or more have passed since onset. While it is safe, less invasive, and convenient, dynamic CT is also very useful for the early diagnosis of cerebral infarction, for the determination of the treatment at the acute stage and for the forecasting of hemorrhagic infarction. (J.P.N.)

  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...

  2. 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....

  3. Clinical application of cerebral dynamic perfusion studies

    International Nuclear Information System (INIS)

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

  4. Middle cerebral artery blood velocity and cerebral blood flow and O2 uptake during dynamic exercise

    DEFF Research Database (Denmark)

    Madsen, P L; Sperling, B K; Warming, T; Schmidt, J F; Secher, N H; Wildschiødtz, Gordon; Holm, S; Lassen, N A

    1993-01-01

    Results obtained by the 133Xe clearance method with external detectors and by transcranial Doppler sonography (TCD) suggest that dynamic exercise causes an increase of global average cerebral blood flow (CBF). These data are contradicted by earlier data obtained during less-well-defined conditions....... To investigate this controversy, we applied the Kety-Schmidt technique to measure the global average levels of CBF and cerebral metabolic rate of oxygen (CMRO2) during rest and dynamic exercise. Simultaneously with the determination of CBF and CMRO2, we used TCD to determine mean maximal flow...... velocity in the middle cerebral artery (MCA Vmean). For values of CBF and MCA Vmean a correction for an observed small drop in arterial PCO2 was carried out. Baseline values for global CBF and CMRO2 were 50.7 and 3.63 ml.100 g-1.min-1, respectively. The same values were found during dynamic exercise...

  5. Mechanisms regulating regional cerebral activation during dynamic handgrip in humans

    DEFF Research Database (Denmark)

    Williamson, James; Friedman, D B; Mitchell, J H; Secher, N H; Friberg, L

    1996-01-01

    type of afferent input required for this cerebral activation. The rCBF was measured at +5.0 and +9.0 cm above the orbitomeatal (OM) plane in 13 subjects during 1) rest; 2) dynamic left-hand contractions; 3) postcontraction ischemia (metaboreceptor afferents); and 4) biceps brachii tendon vibration...

  6. Disablement dynamics in children with cerebral paralysis in Saratov

    Directory of Open Access Journals (Sweden)

    G.Yu. Alekseeva

    2010-03-01

    Full Text Available The analysis of statistical indices of children's disablement in case of cerebral paralysis has been represented. It has been established that morbidity of CCP is higher in Leninskiy and Zavodskoy Districts of Saratov. The disablement dynamics of CCP in Saratov is high and has a stable tendency of growing

  7. 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....

  8. 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.

  9. Validation of enhanced and dynamic computed tomography for cerebral ischemia

    International Nuclear Information System (INIS)

    This paper shows the usefulness of enhanced and dynamic CT for ischemic stroke patients. Sixteen patients with disturbance of consciousness or neurological sign who did not have low-density area on plain CT were selected for this study. We performed enhanced CT sequentially. Enhanced CT image, time-density curve and functional image were compared with final infarcted area and occlusion level of cerebral artery. Three patients whose enhanced CT images showed obvious laterality had occlusion of internal carotid (IC) or horizontal portion of middle cerebral artery (M1). Four of five patients whose functional image and time density curve revealed abnormal region had ischemia because of more peripheral vessel occlusion or IC stenosis. Others with no abnormality on all images had lacunar infarction or did not have infarction finally. Occlusion of cerebral artery proximal portion could be diagnosed only with enhanced CT images. If selected slice was fit to the lesion, more distant level of ischemic area could be determined 100% by time-density curve and functional image. This examination takes only about ten minutes without transferring the patient. Enhanced CT and dynamic scan is useful tool to determine the diagnosis and management for ischemic stroke patients. (author)

  10. [Autoregulation in therapeutic effects].

    Science.gov (United States)

    Zilov, V G

    1996-01-01

    Self-regulation as the basic principle in the organization of living beings is analyzed from the viewpoint of the functional system theory for orthodox medicine and nonconventional therapies. Only some therapies in orthodox medicine are based on self-regulation whereas its role in nonconventional or traditional medicine is proposed to be more frequent and important. The paper describes how the similar principle can be clearly understood when the fundamental FST-principle (self-regulation) is used. The problems of the so-called vibrational medicine with its notion of a human being as a multidimensional organism made up of physical/cellular systems in a dynamic interplay with complex regulatory energy fields. Self-regulation is considered to be the crucial principle when subtle energetic medical approaches are applied as a cure. The paper also draws attention to informational processes in the body and its possible role in the mechanisms of orthodox and nonconventional therapies. The idea that the methods of traditional medicine have to be considered as complementary, but not alternative to orthodox, academic medicine is emphasized. PMID:9102075

  11. Personal computer aided cerebral perfusion imaging with dynamic CT

    Institute of Scientific and Technical Information of China (English)

    林燕; 高培毅

    2004-01-01

    @@Reports on the clinical implementation of dynamic computerised tomography (CT) perfusion imaging and quantitative measurement have increased dramatically of late.1-8 The advantages of dynamic CT perfusion imaging and quantitative measurement for the diagnosis of acute cerebral infarction have been acknowledged. However, most overseas CT vendors set perfusion imaging software package as an option for graphic workstation at a too high price for domestic practitioners. To foster the domestic implementation and development of this new technology, we have extended the earlier work.1,2 Applying the theory of central volume principle to DICOM 3.0 standard forms of prime CT images, we developed dynamic CT perfusion imaging and quantitative measure-ment programmes for PCs using Visual C+ + in Windows 98 system.

  12. 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...

  13. Between-centre variability in transfer function analysis, a widely used method for linear quantification of the dynamic pressure–flow relation: The CARNet study

    OpenAIRE

    Meel-van den Abeelen, Aisha S.S.; Simpson, David M.; Wang, Lotte J.Y.; Slump, Cornelis H; Zhang, Rong; Tarumi, Takashi; Rickards, Caroline A.; Payne, Stephen; Mitsis, Georgios D.; Kostoglou, Kyriaki; Marmarelis, Vasilis; Shin, Dae; Tzeng, Yu-Chieh; Ainslie, Philip N; Gommer, Erik

    2014-01-01

    Transfer function analysis (TFA) is a frequently used method to assess dynamic cerebral autoregulation (CA) using spontaneous oscillations in blood pressure (BP) and cerebral blood flow velocity (CBFV). However, controversies and variations exist in how research groups utilise TFA, causing high variability in interpretation. The objective of this study was to evaluate between-centre variability in TFA outcome metrics. 15 centres analysed the same 70 BP and CBFV datasets from healthy subjects ...

  14. Autoregulation of spinal cord blood flow: is the cord a microcosm of the brain

    International Nuclear Information System (INIS)

    The autoregulatory capability of regional areas of the brain and spinal cord was demonstrated in 18 rats anesthetized with a continuous infusion of intravenous pentothal. Blood flow was measured by the injection of radioactive microspheres (Co57, Sn113, Ru103, Sc46). Blood flow measurements were made at varying levels of mean arterial pressure (MAP) which was altered by neosynephrine to raise MAP or trimethaphan to lower MAP. Autoregulation of the spinal cord mirrored that of the brain, with an autoregulatory range of 60 to 120 mm Hg for both tissues. Within this range, cerebral blood flow (CBF) was 59.2 +/- 3.2 ml/100 g/min (SEM) and spinal cord blood flow (SCBF) was 61.1 +/- 3.6. There was no significant difference in CBF and SCBF in the autoregulatory range. Autoregulation was also demonstrated regionally in the left cortex, right cortex, brainstem, thalamus, cerebellum, hippocampus and cervical, thoracic and lumbar cord. This data provides a coherent reference point in establishing autoregulatory curves under barbiturate anesthesia. Further investigation of the effects of other anesthetic agents on autoregulation of the spinal cord is needed. It is possible that intraspinal cord compliance, like intracranial compliance, might be adversely affected by the effects of anesthetics on autoregulation

  15. 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...... groups. However, in contrast to nondiabetic hypertensive patients, intensive BP control reduced CBFV in T2DM- (58±9 to 54±12 cm · s-1) and T2DM+ (57±13 to 52±11 cm · s-1) at 3 months, but CBFV returned to baseline at 6 months only in T2DM-, whereas the reduction in CBFV progressed in T2DM+ (to 48±8 cm...

  16. Semiquantifying regional cerebral blood flow by dynamic CT scanning

    International Nuclear Information System (INIS)

    The study was undertaken to evaluate the semi-quantitative significance of the absolute value obtained by calculating the regional cerebral blood flow index (rCBFI) from dynamic CT in comparison with SPECT. rCBFI was calculated from mean transit time (MTT) and blood capacity index (BCI) obtained by rapidly infusing 50 ml of Omnipurk into the elbow vein by the use of Hitachi's W-600. [rCBFI=BCI/MTT unit/sec (U/S)] measurment of the rCBF by SPECT was made according to the semi-quantitative method by Matsuda et al. by the use of SHIMADZU's improved type HEADTOME SET-050 with rapid infusion of 123I-IMP in 3.5 m Ci from the elbow vein. Patients in whom no abnormality was observed in the cardiopulmonary function were enrolled as subjects. The rCBFI in each intracranial site was calculated from dynamic CT in 10 normal adults (aged 35-60, averaging 46.7) as subjects and compared with the rCBF obtained from SPECT in the same cases and same site. Comparative investigation was made similarly between rCBFI and rCBF regarding 10 patients with tracranial diseases (age 29-65, averaging 51.2). The mean rCBFIs in the normal adults obtained from dynamic CT were 1.15±0.18 U/S in the frontal lobar cortex, 1.28±0.19 U/S in the temporal lobar cortex, 1.43±0.1 U/S in the occipital lobar cortex, 1.27±0.2 U/S in the basal ganglia region and 0.43±0.1 U/S in the white matter. On the other hand, the mean rCBFs by SPECT were 47.36±3.93 ml/100 g/min, 55.19±2.22 ml/100 g/min, 61.92±5.42 ml/100 g/min, 54.38±3.51 ml/100 g/min and 38.68±6.18 ml/100 g/min, respectively. Positive correlation was observed between rCBFIs and rCBFs of 10 normal adults and 10 patients with intracranial disease, totalling 20 cases (r=0.79, P<0.005). The rCBFI by dynamic CT has a correlation with the rCBF by SPECT, suggesting the possibility of its evaluation as an absolute value, though semi-quantitatively. (author)

  17. Cerebral hyperperfusion following carotid endarterectomy

    DEFF Research Database (Denmark)

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

    1987-01-01

    Serial measurements of cerebral blood flow (CBF) were performed in 56 patients before and one to four times after uncomplicated carotid endarterectomy. The findings were related to the ratio between internal carotid artery (ICA) and common carotid artery (CCA) mean pressures. Within the 1st...... 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....

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

    OpenAIRE

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

    2012-01-01

    Background It is difficult to non-invasively visualize changes in regional cerebral blood flow caused by manual compression of the carotid artery. Purpose To visualize dynamic changes in regional cerebral blood flow during and after manual compression of the carotid artery. Material and Methods Two healthy volunteers were recruited. Anatomic features and flow directions in the circle of Willis were evaluated with time-of-flight magnetic resonance angiography (MRA) and two-dimensional phase-co...

  19. Human cerebral blood volume measurements using dynamic contrast enhancement in comparison to dynamic susceptibility contrast MRI

    International Nuclear Information System (INIS)

    Cerebral blood volume (CBV) is an important parameter for the assessment of brain tumors, usually obtained using dynamic susceptibility contrast (DSC) MRI. However, this method often suffers from low spatial resolution and high sensitivity to susceptibility artifacts and usually does not take into account the effect of tissue permeability. The plasma volume (vp) can also be extracted from dynamic contrast enhancement (DCE) MRI. The aim of this study was to investigate whether DCE can be used for the measurement of cerebral blood volume in place of DSC for the assessment of patients with brain tumors. Twenty-eight subjects (17 healthy subjects and 11 patients with glioblastoma) were scanned using DCE and DSC. vp and CBV values were measured and compared in different brain components in healthy subjects and in the tumor area in patients. Significant high correlations were detected between vp and CBV in healthy subjects in the different brain components; white matter, gray matter, and arteries, correlating with the known increased tissue vascularity, and within the tumor area in patients. This work proposes the use of DCE as an alternative method to DSC for the assessment of blood volume, given the advantages of its higher spatial resolution, its lower sensitivity to susceptibility artifacts, and its ability to provide additional information regarding tissue permeability. (orig.)

  20. Human cerebral blood volume measurements using dynamic contrast enhancement in comparison to dynamic susceptibility contrast MRI

    Energy Technology Data Exchange (ETDEWEB)

    Artzi, Moran [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Tel Aviv University, Sackler Faculty of Medicine, Tel Aviv (Israel); Liberman, Gilad; Vitinshtein, Faina; Aizenstein, Orna [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Nadav, Guy [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Tel Aviv University, Faculty of Engineering, Tel Aviv (Israel); Blumenthal, Deborah T.; Bokstein, Felix [Tel Aviv Sourasky Medical Center, Neuro-Oncology Service, Tel Aviv (Israel); Bashat, Dafna Ben [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Tel Aviv University, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv (Israel)

    2015-07-15

    Cerebral blood volume (CBV) is an important parameter for the assessment of brain tumors, usually obtained using dynamic susceptibility contrast (DSC) MRI. However, this method often suffers from low spatial resolution and high sensitivity to susceptibility artifacts and usually does not take into account the effect of tissue permeability. The plasma volume (v{sub p}) can also be extracted from dynamic contrast enhancement (DCE) MRI. The aim of this study was to investigate whether DCE can be used for the measurement of cerebral blood volume in place of DSC for the assessment of patients with brain tumors. Twenty-eight subjects (17 healthy subjects and 11 patients with glioblastoma) were scanned using DCE and DSC. v{sub p} and CBV values were measured and compared in different brain components in healthy subjects and in the tumor area in patients. Significant high correlations were detected between v{sub p} and CBV in healthy subjects in the different brain components; white matter, gray matter, and arteries, correlating with the known increased tissue vascularity, and within the tumor area in patients. This work proposes the use of DCE as an alternative method to DSC for the assessment of blood volume, given the advantages of its higher spatial resolution, its lower sensitivity to susceptibility artifacts, and its ability to provide additional information regarding tissue permeability. (orig.)

  1. 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.

  2. The Algorithmic Autoregulation Software Development Methodology

    OpenAIRE

    Fabbri, Renato; Fabbri, Ricardo; Vieira, Vilson; Penalva, Daniel; Shiga, Danilo; Mendonca, Marcos; Negrao, Alexandre; Zambianchi, Lucas; Thume, Gabriela

    2016-01-01

    We present a new self-regulating methodology for coordinating distributed team work called Algorithmic Autoregulation (AA), based on recent social networking concepts and individual merit. Team members take on an egalitarian role, and stay voluntarily logged into so-called AA sessions for part of their time (e.g. 2 hours per day), during which they create periodical logs - short text sentences - they wish to share about their activity with the team. These logs are publicly aggregated in a web...

  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; Marmarelis, V Z

    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...... between SDR and SHR. The predictive ability, as determined by normalized mean-square errors (NMSE), of a third-order Volterra model is better than for a linear model. This decrease in NMSE with a third-order model from that of a linear model is especially evident at frequencies below 0.2 Hz. Furthermore......, 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. Regulation of the cerebral circulation: bedside assessment and clinical implications.

    Science.gov (United States)

    Donnelly, Joseph; Budohoski, Karol P; Smielewski, Peter; Czosnyka, Marek

    2016-01-01

    Regulation of the cerebral circulation relies on the complex interplay between cardiovascular, respiratory, and neural physiology. In health, these physiologic systems act to maintain an adequate cerebral blood flow (CBF) through modulation of hydrodynamic parameters; the resistance of cerebral vessels, and the arterial, intracranial, and venous pressures. In critical illness, however, one or more of these parameters can be compromised, raising the possibility of disturbed CBF regulation and its pathophysiologic sequelae. Rigorous assessment of the cerebral circulation requires not only measuring CBF and its hydrodynamic determinants but also assessing the stability of CBF in response to changes in arterial pressure (cerebral autoregulation), the reactivity of CBF to a vasodilator (carbon dioxide reactivity, for example), and the dynamic regulation of arterial pressure (baroreceptor sensitivity). Ideally, cerebral circulation monitors in critical care should be continuous, physically robust, allow for both regional and global CBF assessment, and be conducive to application at the bedside. Regulation of the cerebral circulation is impaired not only in primary neurologic conditions that affect the vasculature such as subarachnoid haemorrhage and stroke, but also in conditions that affect the regulation of intracranial pressure (such as traumatic brain injury and hydrocephalus) or arterial blood pressure (sepsis or cardiac dysfunction). Importantly, this impairment is often associated with poor patient outcome. At present, assessment of the cerebral circulation is primarily used as a research tool to elucidate pathophysiology or prognosis. However, when combined with other physiologic signals and online analytical techniques, cerebral circulation monitoring has the appealing potential to not only prognosticate patients, but also direct critical care management. PMID:27145751

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

    International Nuclear Information System (INIS)

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

  6. 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

  7. Bimodal oscillations in nephron autoregulation

    DEFF Research Database (Denmark)

    Sosnovtseva, Olga; Pavlov, A.N.; Mosekilde, Erik;

    2002-01-01

    The individual functional unit of the kidney (the nephron) displays oscillations in its pressure and flow regulation at two different time scales: fast oscillations associated with a myogenic dynamics of the afferent arteriole, and slower oscillations arising from a delay in the tubuloglomerular ...

  8. Semiquantitative dynamic computed tomography to predict response to anti-platelet therapy in acute cerebral infarction

    Energy Technology Data Exchange (ETDEWEB)

    Chokyu, K.; Shimizu, K. [Department of Neurosurgery, Kochi Medical School, Kohasu (Japan); Fukumoto, M. [Department of Radiology, Kochi Medical School (Japan); Mori, T. [Department of Stroke Treatment, Shonan Kamakura General Hospital, Kanagawa (Japan); Mokudai, T.; Mori, K. [Mominoki Hospital, Kochi (Japan)

    2002-04-01

    We investigated whether dynamic computed tomography (CT) in patients with acute cerebral infarction could identify patients likely to respond to anti-platelet therapy. Seventy patients underwent semiquantitative dynamic CT within 6 h as well as cerebral angiography. All then received anti-platelet therapy with a thromboxane A2 synthetase inhibitor. Peak value (pv) and time-to-peak (tp) (time-density curves) for the Sylvian fissure were extracted from dynamic CT data and standardizing interpatient data, two indices, PV/TP index and TP index, were prepared following a standard semiquantitative manner. Both PV/TP index and TP index were effective in discriminating between 48 responders (modified Rankin scale (mRS): 0 to 2) and 22 non-responders (mRS: 3 to 5, or death: 6; both P<0.0001). High PV/TP index ({>=}0.8) was a strong indicator of favorable response. Most of these patients maintained regional cerebral blood flow (rCBF) via anterograde flow or collaterals, with a TP index {<=}1.1. Low PV/TP index ({<=}0.4) predicted non-response associated with increased TP index (>1.1) and non-compensated rCBF. Intermediate PV/TP values could not predict outcome. Dynamic CT prior to therapy can identify patients with acute cerebral infarction who are treatable with anti-platelet therapy alone. (orig.)

  9. Cerebral blood flow during submaximal and maximal dynamic exercise in humans

    DEFF Research Database (Denmark)

    Thomas, S N; Schroeder, T; Secher, N H; Mitchell, J H

    1989-01-01

    Cerebral blood flow (CBF) in humans was measured at rest and during dynamic exercise on a cycle ergometer corresponding to 56% (range 27-85) of maximal O2 uptake (VO2max). Exercise bouts were performed by 16 male and female subjects, lasted 15 min each, and were carried out in a semisupine positi...

  10. Dynamic Systems Theory and Management of Children with Cerebral Palsy: Unresolved Issues.

    Science.gov (United States)

    Darrah, Johanna; Bartlett, Doreen

    1995-01-01

    This article explains dynamic systems theory (DST), a theoretical framework for the management of children with a diagnosis of cerebral palsy. Three tenets of DST (self-organization of movement, transition, and rate-limiting factors) are examined in light of potential intervention strategies. The need for research to evaluate DST assumptions and…

  11. 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....... Using it even without knowing the exact level of CBF and CBV, it is possible to aim to keep CBF and CBV stable. Futureresearch should focus on development of monitoring tools, gaining more insight in neonatal cerebral autoregulation, and demonstrating clinical benefits of a 'cerebral perfusion...

  12. Dynamic regulation of cerebral DNA repair genes by psychological stress

    DEFF Research Database (Denmark)

    Forsberg, Kristin; Aalling, Nadia; Wörtwein, Gitta;

    2015-01-01

    Neuronal genotoxic insults from oxidative stress constitute a putative molecular link between stress and depression on the one hand, and cognitive dysfunction and dementia risk on the other. Oxidative modifications to DNA are repaired by specific enzymes; a process that plays a critical role...... for maintaining genomic integrity. The aim of the present study was to characterize the pattern of cerebral DNA repair enzyme regulation after stress through the quantification of a targeted range of gene products involved in different types of DNA repair. 72 male Sprague-Dawley rats were subjected to either...... restraint stress (6h/day) or daily handling (controls), and sacrificed after 1, 7 or 21 stress sessions. The mRNA expression of seven genes (Ogg1, Ape1, Ung1, Neil1, Xrcc1, Ercc1, Nudt1) involved in the repair of oxidatively damaged DNA was determined by quantitative real time polymerase chain reaction...

  13. Study of the Dynamics of Transcephalic Cerebral Impedance Data during Cardio-Vascular Surgery

    Science.gov (United States)

    Atefi, S. R.; Seoane, F.; Lindecrantz, K.

    2013-04-01

    Postoperative neurological deficits are one of the risks associated with cardio vascular surgery, necessitating development of new techniques for cerebral monitoring. In this study an experimental observation regarding the dynamics of transcephalic Electrical Bioimpedance (EBI) in patients undergoing cardiac surgery with and without extracorporeal circulation (ECC) was conducted to investigate the potential use of electrical Bioimpedance for cerebral monitoring in cardio vascular surgery. Tetrapolar transcephalic EBI measurements at single frequency of 50 kHz were recorded prior to and during cardio vascular surgery. The obtained results show that the transcephalic impedance decreases in both groups of patients as operation starts, however slight differences in these two groups were also observed with the cerebral impedance reduction in patients having no ECC being less common and not as pronounced as in the ECC group. Changes in the cerebral impedance were in agreement with changes of haematocrit and temperature. The origin of EBI changes is still unexplained however these results encourage us to continue investigating the application of electrical bioimpedance cerebral monitoring clinically.

  14. Study of the Dynamics of Transcephalic Cerebral Impedance Data during Cardio-Vascular Surgery

    International Nuclear Information System (INIS)

    Postoperative neurological deficits are one of the risks associated with cardio vascular surgery, necessitating development of new techniques for cerebral monitoring. In this study an experimental observation regarding the dynamics of transcephalic Electrical Bioimpedance (EBI) in patients undergoing cardiac surgery with and without extracorporeal circulation (ECC) was conducted to investigate the potential use of electrical Bioimpedance for cerebral monitoring in cardio vascular surgery. Tetrapolar transcephalic EBI measurements at single frequency of 50 kHz were recorded prior to and during cardio vascular surgery. The obtained results show that the transcephalic impedance decreases in both groups of patients as operation starts, however slight differences in these two groups were also observed with the cerebral impedance reduction in patients having no ECC being less common and not as pronounced as in the ECC group. Changes in the cerebral impedance were in agreement with changes of haematocrit and temperature. The origin of EBI changes is still unexplained however these results encourage us to continue investigating the application of electrical bioimpedance cerebral monitoring clinically.

  15. A study for the correlation of hemorrhagic cerebral infarction with the hemodynamics measured by dynamic CT

    International Nuclear Information System (INIS)

    In 15 cases of cerebral infarction (9 embolisms, 6 thromboses), dynamic CT scans were repeatedly undertaken during 4 week period of stroke. The ratio of peak height to mean transit time (PH/MTT), which was calculated from density time curve, was used as an index of cerebral blood flow. Hemorrhagic infarction was defined as a high density area with CT value over 50 within low density area. The PH/MTT was significantly increased after the appearance of hemorrhagic infarction. Nine of 10 areas, in which hemorrhagic infarctions were not recognized after recoverry of PH/MTT to over 0.5, did not show hemorrhagic infarctions during 4 week period of stroke. The areas in which hemorrhagic infarctions appeared during 4 week period of stroke had mdore prolonged period of low PH/MTT values than the areas in which hemorrhagic infarctions were not recognized. In conclusion dynamic CT is useful for predicting hemorrhagic infarction. (author)

  16. Study for the correlation of hemorrhagic cerebral infarction with the hemodynamics measured by dynamic CT

    Energy Technology Data Exchange (ETDEWEB)

    Shibagaki, Yasuro (Tokyo Women' s Medical Coll. (Japan))

    1989-06-01

    In 15 cases of cerebral infarction (9 embolisms, 6 thromboses), dynamic CT scans were repeatedly undertaken during 4 week period of stroke. The ratio of peak height to mean transit time (PH/MTT), which was calculated from density time curve, was used as an index of cerebral blood flow. Hemorrhagic infarction was defined as a high density area with CT value over 50 within low density area. The PH/MTT was significantly increased after the appearance of hemorrhagic infarction. Nine of 10 areas, in which hemorrhagic infarctions were not recognized after recoverry of PH/MTT to over 0.5, did not show hemorrhagic infarctions during 4 week period of stroke. The areas in which hemorrhagic infarctions appeared during 4 week period of stroke had mdore prolonged period of low PH/MTT values than the areas in which hemorrhagic infarctions were not recognized. In conclusion dynamic CT is useful for predicting hemorrhagic infarction. (author).

  17. 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...

  18. Renal autoregulation in medical therapy of renovascular hypertension

    OpenAIRE

    Lubas, Arkadiusz; Żelichowski, Grzegorz; Próchnicka, Agnieszka; Wiśniewska, Magdalena; Wańkowicz, Zofia

    2010-01-01

    Introduction Renovascular hypertension (RVH) is caused by renal ischaemia associated with haemodynamically significant renal artery stenosis (RAS). The choice of optimal treatment of atherosclerotic RAS is still controversial. Increase in the renal resistive index (RI) value after captopril administration is considered to indicate preserved renal autoregulation. The objective of the study was to assess the effect of medical therapy of RVH on renal autoregulation efficiency in patients with at...

  19. The effects of age on the spontaneous low-frequency oscillations in cerebral and systemic cardiovascular dynamics

    International Nuclear Information System (INIS)

    Although the effects of ageing on cardiovascular control and particularly the response to orthostatic stress have been the subject of many studies, the interaction between the cardiovascular and cerebral regulation mechanisms is still not fully understood. Wavelet cross-correlation is used here to assess the coupling and synchronization between low-frequency oscillations (LFOs) observed in cerebral hemodynamics, as measured using cerebral blood flow velocity (CBFV) and cerebral oxygenation (O2Hb), and systemic cardiovascular dynamics, as measured using heart rate (HR) and arterial blood pressure (ABP), in both old and young healthy subjects undergoing head-up tilt table testing. Statistically significant increases in correlation values are found in the interaction of cerebral and cardiovascular LFOs for young subjects (P 2Hb and ABP–O2Hb), but not in old subjects under orthostatic stress. The coupling between the cerebrovascular and wider cardiovascular systems in response to orthostatic stress thus appears to be impaired with ageing

  20. Reconstruction of cerebral hemodynamics with dynamic contrast-enhanced time-resolved near-infrared measurements before and during ischemia

    Science.gov (United States)

    Elliott, Jonathan T.; Diop, Mamadou; Morrison, Laura B.; Lee, Ting-Yim; St. Lawrence, Keith

    2013-03-01

    We present a dynamic contrast-enhanced near-infrared (DCE-NIR) technique that is capable of non-invasive quantification of cerebral hemodynamics in adults. The challenge of removing extracerebral contamination is overcome through the use of multi-distance time-resolved DCE-NIR combined with the kinetic deconvolution optical reconstruction (KDOR) analytical method. As proof-of-principle, cerebral blood flow, cerebral blood volume and mean transit time recovered with DCE-NIR are compared with CT perfusion values in an adult pig during normocapnia, hypocapnia, and ischemia. Measurements of blood flow acquired with DCE-NIR were compared against concomitant measurements using CT Perfusion.

  1. d3D-CTA (dynamic 3D-CTA) for cerebral infarction using multi-detector row CT (MDCT)

    International Nuclear Information System (INIS)

    Since three-dimensional-CT angiography (3D-CTA) can demonstrate occlusion or stenosis of the arteries, it has been employed for the diagnosis of patients with cerebral infarction. However, it does not provide information on the blood-flow dynamics. We therefore developed a new technique, d3D-CTA (dynamic 3D-CTA), that yields 3D images of the vessels and hemodynamics. We assessed whether or not our technique could be applied to patients with cerebral infarction. We subjected 41 patients with cerebral infarction to d3D-CTA (17 lacunar infarctions, 14 cardioembolisms and 10 atherosclerotic infarctions). d3D-CTA was performed using a multi-detector row CT scanner with 64 detectors. Contrast medium was injected at a speed of 6 ml/s (a total volume of 30 ml). The scanning was performed for 30 sec with a scan delay of 5 sec. In all cases, we successfully developed d3D-CTA. The d3D-CTA provided us with information on the vascular structures, hemodynamics and cerebral perfusion. Although our technique, d3D-CTA, has some disadvantages such as a limited scan range (32 mm) and relatively high radiation dose, it does facilitate the acquisition of information on the vascular anatomy, flow dynamics on 3D images and cerebral perfusion. We conclude that d3D-CTA can be applied for the diagnosis and treatment of patients with cerebral infarction. (author)

  2. 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.

  3. Cerebral spinal fluid dynamics: effect of hypoxia and implications for high-altitude illness.

    Science.gov (United States)

    Lawley, Justin S; Levine, Benjamin D; Williams, Michael A; Malm, Jon; Eklund, Anders; Polaner, David M; Subudhi, Andrew W; Hackett, Peter H; Roach, Robert C

    2016-01-15

    The pathophysiology of acute mountain sickness and high-altitude cerebral edema, the cerebral forms of high-altitude illness, remain uncertain and controversial. Persistently elevated or pathological fluctuations in intracranial pressure are thought to cause symptoms similar to those reported by individuals suffering cerebral forms of high-altitude illness. This review first focuses on the basic physiology of the craniospinal system, including a detailed discussion of the long-term and dynamic regulation of intracranial pressure. Thereafter, we critically examine the available literature, based primarily on invasive pressure monitoring, that suggests intracranial pressure is acutely elevated at altitude due to brain swelling and/or elevated sagittal sinus pressure, but normalizes over time. We hypothesize that fluctuations in intracranial pressure occur around a slightly elevated or normal mean intracranial pressure, in conjunction with oscillations in arterial Po2 and arterial blood pressure. Then these modest fluctuations in intracranial pressure, in concert with direct vascular stretch due to dilatation and/or increased blood pressure transmission, activate the trigeminal vascular system and cause symptoms of acute mountain sickness. Elevated brain water (vasogenic edema) may be due to breakdown of the blood-brain barrier. However, new information suggests cerebral spinal fluid flux into the brain may be an important factor. Regardless of the source (or mechanisms responsible) for the excess brain water, brain swelling occurs, and a "tight fit" brain would be a major risk factor to produce symptoms; activities that produce large changes in brain volume and cause fluctuations in blood pressure are likely contributing factors. PMID:26494441

  4. Effect of a Dynamic Seating Surface on Postural Control and Function in Children with Cerebral Palsy

    DEFF Research Database (Denmark)

    Meyer, Erna Rosenlund; Trew, Lisa

    Purpose: The purpose was to investigate if a seating system involving a dynamic material covering the seat back and base improves postural control, alignment and function in children with cerebral palsy and to investigate consequences of adapting The Seated Postural Control Measure to a target...... point in a seatback and seat bottom made of a dynamic material and designed to give ergonomic support and is part of research collaboration in the Northern Region of Denmark, supported financial by the named partners and the European Regional Development Fund. Participants: A total of 10 children, age...... 10-16 from a school for children with special needs in the Northern Region of Denmark. Methods: In this clinical study two seating systems were compared; the new developed dynamic seating system (DSS) versus a traditional seating system of various types (TSS). The study was approved by the Danish...

  5. Dynamic cone beam CT angiography of carotid and cerebral arteries using canine model

    Energy Technology Data Exchange (ETDEWEB)

    Cai Weixing; Zhao Binghui; Conover, David; Liu Jiangkun; Ning Ruola [Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642 (United States); Department of Radiology, Shanghai 6th People' s Hospital, 600 Yishan Road, Xuhui, Shanghai (China); Koning Corporation, Lennox Tech Enterprise Center, 150 Lucius Gordon Drive Suite 112, West Henrietta, New York 14586 (United States); Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642 (United States); Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642 (United States) and Koning Corporation, Lennox Tech Enterprise Center, 150 Lucius Gordon Drive Suite 112, West Henrietta, New York 14586 (United States)

    2012-01-15

    Purpose: This research is designed to develop and evaluate a flat-panel detector-based dynamic cone beam CT system for dynamic angiography imaging, which is able to provide both dynamic functional information and dynamic anatomic information from one multirevolution cone beam CT scan. Methods: A dynamic cone beam CT scan acquired projections over four revolutions within a time window of 40 s after contrast agent injection through a femoral vein to cover the entire wash-in and wash-out phases. A dynamic cone beam CT reconstruction algorithm was utilized and a novel recovery method was developed to correct the time-enhancement curve of contrast flow. From the same data set, both projection-based subtraction and reconstruction-based subtraction approaches were utilized and compared to remove the background tissues and visualize the 3D vascular structure to provide the dynamic anatomic information. Results: Through computer simulations, the new recovery algorithm for dynamic time-enhancement curves was optimized and showed excellent accuracy to recover the actual contrast flow. Canine model experiments also indicated that the recovered time-enhancement curves from dynamic cone beam CT imaging agreed well with that of an IV-digital subtraction angiography (DSA) study. The dynamic vascular structures reconstructed using both projection-based subtraction and reconstruction-based subtraction were almost identical as the differences between them were comparable to the background noise level. At the enhancement peak, all the major carotid and cerebral arteries and the Circle of Willis could be clearly observed. Conclusions: The proposed dynamic cone beam CT approach can accurately recover the actual contrast flow, and dynamic anatomic imaging can be obtained with high isotropic 3D resolution. This approach is promising for diagnosis and treatment planning of vascular diseases and strokes.

  6. Dynamic cone beam CT angiography of carotid and cerebral arteries using canine model

    International Nuclear Information System (INIS)

    Purpose: This research is designed to develop and evaluate a flat-panel detector-based dynamic cone beam CT system for dynamic angiography imaging, which is able to provide both dynamic functional information and dynamic anatomic information from one multirevolution cone beam CT scan. Methods: A dynamic cone beam CT scan acquired projections over four revolutions within a time window of 40 s after contrast agent injection through a femoral vein to cover the entire wash-in and wash-out phases. A dynamic cone beam CT reconstruction algorithm was utilized and a novel recovery method was developed to correct the time-enhancement curve of contrast flow. From the same data set, both projection-based subtraction and reconstruction-based subtraction approaches were utilized and compared to remove the background tissues and visualize the 3D vascular structure to provide the dynamic anatomic information. Results: Through computer simulations, the new recovery algorithm for dynamic time-enhancement curves was optimized and showed excellent accuracy to recover the actual contrast flow. Canine model experiments also indicated that the recovered time-enhancement curves from dynamic cone beam CT imaging agreed well with that of an IV-digital subtraction angiography (DSA) study. The dynamic vascular structures reconstructed using both projection-based subtraction and reconstruction-based subtraction were almost identical as the differences between them were comparable to the background noise level. At the enhancement peak, all the major carotid and cerebral arteries and the Circle of Willis could be clearly observed. Conclusions: The proposed dynamic cone beam CT approach can accurately recover the actual contrast flow, and dynamic anatomic imaging can be obtained with high isotropic 3D resolution. This approach is promising for diagnosis and treatment planning of vascular diseases and strokes.

  7. The Impacts of Spastic Cerebral Palsy Children on Dynamic Balance Performance

    Directory of Open Access Journals (Sweden)

    M.S. Saba

    2006-07-01

    Full Text Available Introduction & Objective: Despite of many studies on cerebral palsy (CP, the impacts of this disease on musculoskeletal function especially on the dynamic balance of the CP patients is not well understood. This information can improve the quality of the treatment. The objectives of this study were to evaluate the differences between the dynamic balance performance of normal and CP children in different conditions.Materials & Methods: Ten children with spastic diplegia cerebral palsy between 8 to15 years of age and with mean weight and height of 30.8±5.7kg and 1.35±0.09m respectively, underwent an exercise therapy program for 12 weeks. A stability platform system was used to measure the deviation on the mean point of the application of the center of gravity (COG from the center of base of support (COBOS. The balance tests were repeated on stable and unstable base of support as well as with and without shoes. Results: It was shown that the mean deviation of COG of the CP children improves about 25% after exercise therapy (p=0.001. The most improvement was in mid-stable and unstable of base of support as well as in AP direction. Mean deviations of COG was near to natural pattern Conclusion: The mean deviation of COG of the CP patients was significantly increased in dynamic standing which shows the poor function of the proprioceptive system in these children. Exercise therapy improves the mean deviation of COG in dynamic standing. These results show the importance of the shoes on the treatment procedures of the spastic CP children.

  8. Dynamic FDG PET for assessing early effects of cerebral hypoxia and resuscitation in new-born pigs

    International Nuclear Information System (INIS)

    Changes in cerebral glucose metabolism may be an early prognostic indicator of perinatal hypoxic-ischaemic injury. In this study dynamic 18F-FDG PET was used to evaluate cerebral glucose metabolism in piglets after global perinatal hypoxia and the impact of the resuscitation strategy using room air or hyperoxia. New-born piglets (n = 16) underwent 60 min of global hypoxia followed by 30 min of resuscitation with a fraction of inspired oxygen (FiO2) of 0.21 or 1.0. Dynamic FDG PET, using a microPET system, was performed at baseline and repeated at the end of resuscitation under stabilized haemodynamic conditions. MRI at 3 T was performed for anatomic correlation. Global and regional cerebral metabolic rates of glucose (CMRgl) were assessed by Patlak analysis for the two time-points and resuscitation groups. Global hypoxia was found to cause an immediate decrease in cerebral glucose metabolism from a baseline level (mean ± SD) of 21.2 ± 7.9 to 12.6 ± 4.7 μmol/min/100 g (p gl but no significant differences in global or regional CMRgl between the resuscitation groups were found. Dynamic FDG PET detected decreased cerebral glucose metabolism early after perinatal hypoxia in piglets. The decrease in CMRgl may indicate early changes of mild cerebral hypoxia-ischaemia. No significant effect of hyperoxic resuscitation on the degree of hypometabolism was found in this early phase after hypoxia. Cerebral FDG PET can provide new insights into mechanisms of perinatal hypoxic-ischaemic injury where early detection plays an important role in instituting therapy. (orig.)

  9. Dynamic Changes of the CT Perfusion Parameters in the Embolic Model of Cerebral Ischemia

    Institute of Scientific and Technical Information of China (English)

    陈唯唯; 漆剑频; 张进华; 黄文华; 宋金梅

    2004-01-01

    To study the dynamic changes of CT perfusion parameters during the first 12 h in the embolic cerebral ischemia models. Local cerebral ischemia model were established in 7 New Zealand white rabbits. All CT scans were performed with a GE Lightspeed 16 multislice CT. Following the baseline scan, further CT perfusion scans were performed at the same locations 20 min, 1-6 h and8, 10 and 12 h after the embolus delivery. Maps of all parameters were obtained by CT perfusion software at each time point. The brains, taken 12 h after the scan, were sliced corresponding to the positions of the CT slices and stained by 2,3,5-triphenyltetrazolium chloride (TTC). On the basis of the TTC results, the ischemicsides were divided into 3 regions: core, penumbra and the relatively normal region. The changes of all parameters were then divided into 3 stages. In the first two hours (the first stage), the CBV dropped more remarkably in the core than in the penumbra but rose slightly in the relatively normal region while the CBF decreased and MTT, TTP extended in all regions to varying degrees. In the 2nd-5th h (the second stage), all the parameters fluctuated slightly around a certain level. In the 5th-12th h (the third stage), the CBV and CBF dropped,and MTT and TTP were prolonged or shortened slightly in the core and penumbra though much notably in the former while the CBV, CBF roseand MTT, TTP were shortened remarkably in the relatively normal region. We experimentally demonstrated that the location and extent of cerebral ischemia could be accurately assessed by CT perfusion imaging. The pathophysiology of the ischemia could be reflected by the CT perfusion to varying degrees.

  10. Dynamic gene expression in the human cerebral cortex distinguishes children from adults.

    Science.gov (United States)

    Sterner, Kirstin N; Weckle, Amy; Chugani, Harry T; Tarca, Adi L; Sherwood, Chet C; Hof, Patrick R; Kuzawa, Christopher W; Boddy, Amy M; Abbas, Asad; Raaum, Ryan L; Grégoire, Lucie; Lipovich, Leonard; Grossman, Lawrence I; Uddin, Monica; Goodman, Morris; Wildman, Derek E

    2012-01-01

    In comparison with other primate species, humans have an extended juvenile period during which the brain is more plastic. In the current study we sought to examine gene expression in the cerebral cortex during development in the context of this adaptive plasticity. We introduce an approach designed to discriminate genes with variable as opposed to uniform patterns of gene expression and found that greater inter-individual variance is observed among children than among adults. For the 337 transcripts that show this pattern, we found a significant overrepresentation of genes annotated to the immune system process (pFDR ~/= 0). Moreover, genes known to be important in neuronal function, such as brain-derived neurotrophic factor (BDNF), are included among the genes more variably expressed in childhood. We propose that the developmental period of heightened childhood neuronal plasticity is characterized by more dynamic patterns of gene expression in the cerebral cortex compared to adulthood when the brain is less plastic. That an overabundance of these genes are annotated to the immune system suggests that the functions of these genes can be thought of not only in the context of antigen processing and presentation, but also in the context of nervous system development. PMID:22666384

  11. [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. PMID:8209591

  12. 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. In th...

  13. Comprehensive validation of computational fluid dynamics simulationsof in-vivo blood flow in patient-specific cerebral aneurysms

    NARCIS (Netherlands)

    Sun, Q.; Groth, A.; Aach, T.

    2012-01-01

    Purpose: Recently, image-based computational fluid dynamic (CFD) simulations have been proposed to investigate the local hemodynamics inside human cerebral aneurysms. It is suggested that the knowledge ofthe computed three-dimensional flow fields can be used to assist clinical risk assessment and tr

  14. The effect of ventricular assist devices on cerebral blood flow and blood pressure fractality

    International Nuclear Information System (INIS)

    Biological signals often exhibit self-similar or fractal scaling characteristics which may reflect intrinsic adaptability to their underlying physiological system. This study analysed fractal dynamics of cerebral blood flow in patients supported with ventricular assist devices (VAD) to ascertain if sustained modifications of blood pressure waveform affect cerebral blood flow fractality. Simultaneous recordings of arterial blood pressure and cerebral blood flow velocity using transcranial Doppler were obtained from five cardiogenic shock patients supported by VAD, five matched control patients and five healthy subjects. Computation of a fractal scaling exponent (α) at the low-frequency time scale by detrended fluctuation analysis showed that cerebral blood flow velocity exhibited 1/f fractal scaling in both patient groups (α = 0.95 ± 0.09 and 0.97 ± 0.12, respectively) as well as in the healthy subjects (α = 0.86 ± 0.07). In contrast, fluctuation in blood pressure was similar to non-fractal white noise in both patient groups (α = 0.53 ± 0.11 and 0.52 ± 0.09, respectively) but exhibited 1/f scaling in the healthy subjects (α = 0.87 ± 0.04, P < 0.05 compared with the patient groups). The preservation of fractality in cerebral blood flow of VAD patients suggests that normal cardiac pulsation and central perfusion pressure changes are not the integral sources of cerebral blood flow fractality and that intrinsic vascular properties such as cerebral autoregulation may be involved. However, there is a clear difference in the fractal scaling properties of arterial blood pressure between the cardiogenic shock patients and the healthy subjects

  15. Phantom-based experimental validation of computational fluid dynamics simulations on cerebral aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Sun Qi; Groth, Alexandra; Bertram, Matthias; Waechter, Irina; Bruijns, Tom; Hermans, Roel; Aach, Til [Philips Research Europe, Weisshausstrasse 2, 52066 Aachen (Germany) and Institute of Imaging and Computer Vision, RWTH Aachen University, Sommerfeldstrasse 24, 52074 Aachen (Germany); Philips Research Europe, Weisshausstrasse 2, 52066 Aachen (Germany); Philips Healthcare, X-Ray Pre-Development, Veenpluis 4-6, 5684PC Best (Netherlands); Institute of Imaging and Computer Vision, RWTH Aachen University, Sommerfeldstrasse 24, 52074 Aachen (Germany)

    2010-09-15

    Purpose: Recently, image-based computational fluid dynamics (CFD) simulation has been applied to investigate the hemodynamics inside human cerebral aneurysms. The knowledge of the computed three-dimensional flow fields is used for clinical risk assessment and treatment decision making. However, the reliability of the application specific CFD results has not been thoroughly validated yet. Methods: In this work, by exploiting a phantom aneurysm model, the authors therefore aim to prove the reliability of the CFD results obtained from simulations with sufficiently accurate input boundary conditions. To confirm the correlation between the CFD results and the reality, virtual angiograms are generated by the simulation pipeline and are quantitatively compared to the experimentally acquired angiograms. In addition, a parametric study has been carried out to systematically investigate the influence of the input parameters associated with the current measuring techniques on the flow patterns. Results: Qualitative and quantitative evaluations demonstrate good agreement between the simulated and the real flow dynamics. Discrepancies of less than 15% are found for the relative root mean square errors of time intensity curve comparisons from each selected characteristic position. The investigated input parameters show different influences on the simulation results, indicating the desired accuracy in the measurements. Conclusions: This study provides a comprehensive validation method of CFD simulation for reproducing the real flow field in the cerebral aneurysm phantom under well controlled conditions. The reliability of the CFD is well confirmed. Through the parametric study, it is possible to assess the degree of validity of the associated CFD model based on the parameter values and their estimated accuracy range.

  16. 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 mRS in patients with heart failure (N = 17; r = 0.69, p mRS in TBI patients (r = 0.63, p mRS in diabetes patients (N = 15), 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). PMID:26085437

  17. Multimodal Pressure-Flow Analysis: Application of Hilbert Huang Transform in Cerebral Blood Flow Regulation

    Directory of Open Access Journals (Sweden)

    Vera Novak

    2008-06-01

    Full Text Available Quantification of nonlinear interactions between two nonstationary signals presents a computational challenge in different research fields, especially for assessments of physiological systems. Traditional approaches that are based on theories of stationary signals cannot resolve nonstationarity-related issues and, thus, cannot reliably assess nonlinear interactions in physiological systems. In this review we discuss a new technique called multimodal pressure flow (MMPF method that utilizes Hilbert-Huang transformation to quantify interaction between nonstationary cerebral blood flow velocity (BFV and blood pressure (BP for the assessment of dynamic cerebral autoregulation (CA. CA is an important mechanism responsible for controlling cerebral blood flow in responses to fluctuations in systemic BP within a few heart-beats. The MMPF analysis decomposes BP and BFV signals into multiple empirical modes adaptively so that the fluctuations caused by a specific physiologic process can be represented in a corresponding empirical mode. Using this technique, we showed that dynamic CA can be characterized by specific phase delays between the decomposed BP and BFV oscillations, and that the phase shifts are significantly reduced in hypertensive, diabetics and stroke subjects with impaired CA. Additionally, the new technique can reliably assess CA using both induced BP/BFV oscillations during clinical tests and spontaneous BP/BFV fluctuations during resting conditions.

  18. Custom sizing of lower limb exoskeleton actuators using gait dynamic modelling of children with cerebral palsy.

    Science.gov (United States)

    Samadi, B; Achiche, S; Parent, A; Ballaz, L; Chouinard, U; Raison, M

    2016-11-01

    The use of exoskeletons as an aid for people with musculoskeletal disorder is the subject to an increasing interest in the research community. These devices are expected to meet the specific needs of users, such as children with cerebral palsy (CP) who are considered a significant population in pediatric rehabilitation. Although these exoskeletons should be designed to ease the movement of people with physical shortcoming, their design is generally based on data obtained from healthy adults, which leads to oversized components that are inadequate to the targeted users. Consequently, the objective of this study is to custom-size the lower limb exoskeleton actuators based on dynamic modeling of the human body for children with CP on the basis of hip, knee, and ankle joint kinematics and dynamics of human body during gait. For this purpose, a multibody modeling of the human body of 3 typically developed children (TD) and 3 children with CP is used. The results show significant differences in gait patterns especially in knee and ankle with respectively 0.39 and -0.33 (Nm/kg) maximum torque differences between TD children and children with CP. This study provides the recommendations to support the design of actuators to normalize the movement of children with CP. PMID:26980164

  19. Multiple-input nonlinear modelling of cerebral haemodynamics using spontaneous arterial blood pressure, end-tidal CO2 and heart rate measurements.

    Science.gov (United States)

    Marmarelis, V Z; Mitsis, G D; Shin, D C; Zhang, R

    2016-05-13

    In order to examine the effect of changes in heart rate (HR) upon cerebral perfusion and autoregulation, we include the HR signal recorded from 18 control subjects as a third input in a two-input model of cerebral haemodynamics that has been used previously to quantify the dynamic effects of changes in arterial blood pressure and end-tidal CO2upon cerebral blood flow velocity (CBFV) measured at the middle cerebral arteries via transcranial Doppler ultrasound. It is shown that the inclusion of HR as a third input reduces the output prediction error in a statistically significant manner, which implies that there is a functional connection between HR changes and CBFV. The inclusion of nonlinearities in the model causes further statistically significant reduction of the output prediction error. To achieve this task, we employ the concept of principal dynamic modes (PDMs) that yields dynamic nonlinear models of multi-input systems using relatively short data records. The obtained PDMs suggest model-driven quantitative hypotheses for the role of sympathetic and parasympathetic activity (corresponding to distinct PDMs) in the underlying physiological mechanisms by virtue of their relative contributions to the model output. These relative PDM contributions are subject-specific and, therefore, may be used to assess personalized characteristics for diagnostic purposes. PMID:27044989

  20. Reduced short term adaptation to robot generated dynamic environment in children affected by Cerebral Palsy

    Directory of Open Access Journals (Sweden)

    Di Rosa Giuseppe

    2011-05-01

    Full Text Available Abstract Background It is known that healthy adults can quickly adapt to a novel dynamic environment, generated by a robotic manipulandum as a structured disturbing force field. We suggest that it may be of clinical interest to evaluate to which extent this kind of motor learning capability is impaired in children affected by cerebal palsy. Methods We adapted the protocol already used with adults, which employs a velocity dependant viscous field, and compared the performance of a group of subjects affected by Cerebral Palsy (CP group, 7 subjects with a Control group of unimpaired age-matched children. The protocol included a familiarization phase (FA, during which no force was applied, a force field adaptation phase (CF, and a wash-out phase (WO in which the field was removed. During the CF phase the field was shut down in a number of randomly selected "catch" trials, which were used in order to evaluate the "learning index" for each single subject and the two groups. Lateral deviation, speed and acceleration peaks and average speed were evaluated for each trajectory; a directional analysis was performed in order to inspect the role of the limb's inertial anisotropy in the different experimental phases. Results During the FA phase the movements of the CP subjects were more curved, displaying greater and variable directional error; over the course of the CF phase both groups showed a decreasing trend in the lateral error and an after-effect at the beginning of the wash-out, but the CP group had a non significant adaptation rate and a lower learning index, suggesting that CP subjects have reduced ability to learn to compensate external force. Moreover, a directional analysis of trajectories confirms that the control group is able to better predict the force field by tuning the kinematic features of the movements along different directions in order to account for the inertial anisotropy of arm. Conclusions Spatial abnormalities in children affected

  1. 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.

  2. Spontaneous obliteration highlights the dynamic nature of cerebral arteriovenous malformations: A case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Su Lone Lim

    2016-01-01

    Conclusion: In our center′s 20-year experience of treatment of cerebral AVMs (approximately 600 cases, this is the only case that has been aborted due to spontaneous obliteration leading us to infer that the incidence of spontaneous AVM obliteration is <1%. Spontaneous obliteration of AVM is a rare but well-established phenomenon that bears testimony to the dynamics of this vascular disorder.

  3. Contribution of hip joint proprioception to static and dynamic balance in cerebral palsy: a case control study

    OpenAIRE

    Damiano, Diane L.; Wingert, Jason R.; Stanley, Christopher J.; Curatalo, Lindsey

    2013-01-01

    Background Balance problems are common in cerebral palsy (CP) but etiology is often uncertain. The classic Romberg test compares ability to maintain standing with eyes open versus closed. Marked instability without vision is a positive test and generally indicates proprioceptive loss. From previous work showing diminished hip joint proprioception in CP, we hypothesized that static and dynamic balance without vision (positive Romberg) would be compromised in CP. Methods Force plate sway and ga...

  4. Arterial spin labelling MRI for assessment of cerebral perfusion in children with moyamoya disease: comparison with dynamic susceptibility contrast MRI

    Energy Technology Data Exchange (ETDEWEB)

    Goetti, Robert [University Children' s Hospital Zurich, Department of Diagnostic Imaging, Zurich (Switzerland); University Hospital Zurich, Department of Diagnostic and Interventional Radiology, Zurich (Switzerland); O' Gorman, Ruth [University Children' s Hospital Zurich, Center for MR Research, Zurich (Switzerland); Khan, Nadia [University Children' s Hospital Zurich, Moyamoya Center, Division of Neurosurgery, Department of Surgery, Zurich (Switzerland); Kellenberger, Christian J.; Scheer, Ianina [University Children' s Hospital Zurich, Department of Diagnostic Imaging, Zurich (Switzerland)

    2013-05-15

    This study seeks to evaluate the diagnostic accuracy of cerebral perfusion imaging with arterial spin labelling (ASL) MR imaging in children with moyamoya disease compared to dynamic susceptibility contrast (DSC) imaging. Ten children (7 females; age, 9.2 {+-} 5.4 years) with moyamoya disease underwent cerebral perfusion imaging with ASL and DSC on a 3-T MRI scanner in the same session. Cerebral perfusion images were acquired with ASL (pulsed continuous 3D ASL sequence, 32 axial slices, TR = 5.5 s, TE = 25 ms, FOV = 24 cm, matrix = 128 x 128) and DSC (gradient echo EPI sequence, 35 volumes of 28 axial slices, TR = 2,000 ms, TE = 36 ms, FOV = 24 cm, matrix = 96 x 96, 0.2 ml/kg Gd-DOTA). Cerebral blood flow maps were generated. ASL and DSC images were qualitatively assessed regarding perfusion of left and right ACA, MCA, and PCA territories by two independent readers using a 3-point-Likert scale and quantitative relative cerebral blood flow (rCBF) was calculated. Correlation between ASL and DSC for qualitative and quantitative assessment and the accuracy of ASL for the detection of reduced perfusion per territory with DSC serving as the standard of reference were calculated. With a good interreader agreement ({kappa} = 0.62) qualitative perfusion assessment with ASL and DSC showed a strong and significant correlation ({rho} = 0.77; p < 0.001), as did quantitative rCBF (r = 0.79; p < 0.001). ASL showed a sensitivity, specificity and accuracy of 94 %, 93 %, and 93 % for the detection of reduced perfusion per territory. In children with moyamoya disease, unenhanced ASL enables the detection of reduced perfusion per vascular territory with a good accuracy compared to contrast-enhanced DSC. (orig.)

  5. Arterial spin labelling MRI for assessment of cerebral perfusion in children with moyamoya disease: comparison with dynamic susceptibility contrast MRI

    International Nuclear Information System (INIS)

    This study seeks to evaluate the diagnostic accuracy of cerebral perfusion imaging with arterial spin labelling (ASL) MR imaging in children with moyamoya disease compared to dynamic susceptibility contrast (DSC) imaging. Ten children (7 females; age, 9.2 ± 5.4 years) with moyamoya disease underwent cerebral perfusion imaging with ASL and DSC on a 3-T MRI scanner in the same session. Cerebral perfusion images were acquired with ASL (pulsed continuous 3D ASL sequence, 32 axial slices, TR = 5.5 s, TE = 25 ms, FOV = 24 cm, matrix = 128 x 128) and DSC (gradient echo EPI sequence, 35 volumes of 28 axial slices, TR = 2,000 ms, TE = 36 ms, FOV = 24 cm, matrix = 96 x 96, 0.2 ml/kg Gd-DOTA). Cerebral blood flow maps were generated. ASL and DSC images were qualitatively assessed regarding perfusion of left and right ACA, MCA, and PCA territories by two independent readers using a 3-point-Likert scale and quantitative relative cerebral blood flow (rCBF) was calculated. Correlation between ASL and DSC for qualitative and quantitative assessment and the accuracy of ASL for the detection of reduced perfusion per territory with DSC serving as the standard of reference were calculated. With a good interreader agreement (κ = 0.62) qualitative perfusion assessment with ASL and DSC showed a strong and significant correlation (ρ = 0.77; p < 0.001), as did quantitative rCBF (r = 0.79; p < 0.001). ASL showed a sensitivity, specificity and accuracy of 94 %, 93 %, and 93 % for the detection of reduced perfusion per territory. In children with moyamoya disease, unenhanced ASL enables the detection of reduced perfusion per vascular territory with a good accuracy compared to contrast-enhanced DSC. (orig.)

  6. Dynamics of activity free radical oxidation reactions in students with cerebral palsy results over the course of the educational process

    Directory of Open Access Journals (Sweden)

    Makarova E.V.

    2012-12-01

    Full Text Available The dynamics of changes activity of reactions is studied freely radical oxidize for students with the consequences of child's cerebral paralysis. 20 students took part in an experiment. Found that the course of study they have more active free radical oxidation reactions and decreases the activity of antiradical protection. Given the use of additional physical activity in aerobic training indicators intracellular antioxidant defense system increased, decreased content of reaction products of lipid peroxidation. However, increased rates of maximum oxygen consumption and increased tolerance of students with cerebral palsy to the consequences of physical activity. It is set that the pathological changes of metabolism for students ground the necessity of application of the differentiated physical loadings. The optimum forms of physical rehabilitation of the aerobic training is the dosed walking, medical swimming, dosed after distance, sometimes and by the corner of getting up pedestrian ascents. Loading is increased due to a volume, but not intensity of exercises.

  7. Characterizing Multimode Interaction in Renal Autoregulation

    DEFF Research Database (Denmark)

    Pavlov, A. N.; Sosnovtseva, Olga; Pavlova, O. N.;

    2008-01-01

    paper emphasizes the significance of complex dynamic phenomena in the normal and pathological function of physiological systems and discusses how simulation methods can help to understand the underlying biological mechanisms. At the present there is no causal explanation of the very slow mode. However......The purpose of this paper is to demonstrate how modern statistical techniques of non-stationary time-series analysis can be used to characterize the mutual interaction among three coexisting rhythms in nephron pressure and flow regulation. Besides a relatively fast vasomotoric rhythm with a period...

  8. Relative fascicle excursion effects on dynamic strength generation during gait in children with cerebral palsy.

    Science.gov (United States)

    Martín Lorenzo, T; Lerma Lara, S; Martínez-Caballero, I; Rocon, E

    2015-10-01

    Evaluation of muscle structure gives us a better understanding of how muscles contribute to force generation which is significantly altered in children with cerebral palsy (CP). While most muscle structure parameters have shown to be significantly correlated to different expressions of strength development in children with CP and typically developing (TD) children, conflicting results are found for muscle fascicle length. Muscle fascicle length determines muscle excursion and velocity, and contrary to what might be expected, correlations of fascicle length to rate of force development have not been found for children with CP. The lack of correlation between muscle fascicle length and rate of force development in children with CP could be due, on the one hand, to the non-optimal joint position adopted for force generation on the isometric strength tests as compared to the position of TD children. On the other hand, the lack of correlation could be due to the erroneous assumption that muscle fascicle length is representative of sarcomere length. Thus, the relationship between muscle architecture parameters reflecting sarcomere length, such as relative fascicle excursions and dynamic power generation, should be assessed. Understanding of the underlying mechanisms of weakness in children with CP is key for individualized prescription and assessment of muscle-targeted interventions. Findings could imply the detection of children operating on the descending limb of the sarcomere length-tension curve, which in turn might be at greater risk of developing crouch gait. Furthermore, relative muscle fascicle excursions could be used as a predictive variable of outcomes related to crouch gait prevention treatments such as strength training. PMID:26138625

  9. Cerebral peritumoral oedema study: Does a single dynamic MR sequence assessing perfusion and permeability can help to differentiate glioblastoma from metastasis?

    International Nuclear Information System (INIS)

    Our purpose was to differentiate glioblastoma from metastasis using a single dynamic MR sequence to assess perfusion and permeability parameters. 24 patients with glioblastoma or cerebral metastasis with peritumoral oedema were recruited and explored with a 3 T MR unit. Post processing used DPTools software. Regions of interest were drawn around contrast enhancement to assess relative cerebral blood volume and permeability parameters. Around the contrast enhancement Glioblastoma present high rCBV with modification of the permeability, metastasis present slight modified rCBV without modification of permeability. In conclusion, peritumoral T2 hypersignal exploration associating morphological MR and functional MR parameters can help to differentiate cerebral metastasis from glioblastoma.

  10. Cerebral vasoconstriction precedes orthostatic intolerance after parabolic flight

    Science.gov (United States)

    Serrador, J. M.; Shoemaker, J. K.; Brown, T. E.; Kassam, M. S.; Bondar, R. L.; Schlegel, T. T.

    2000-01-01

    The effects of brief but repeated bouts of micro- and hypergravity on cerebrovascular responses to head-up tilt (HUT) were examined in 13 individuals after (compared to before) parabolic flight. Middle cerebral artery mean flow velocity (MCA MFV; transcranial Doppler ultrasound), eye level blood pressure (BP) and end tidal CO(2) (P(ET)CO(2)) were measured while supine and during 80 degrees HUT for 30 min or until presyncope. In the postflight tests subjects were classified as being orthostatically tolerant (OT) (n = 7) or intolerant (OI) (n = 6). BP was diminished with HUT in the OT group in both tests (p < 0.05) whereas postflight BP was not different from supine in the OI group. Postflight compared to preflight, the reduction in P(ET)CO(2) with HUT (p < 0.05) increased in both groups, although significantly so only in the OI group (p < 0.05). The OI group also had a significant decrease in supine MCA MFV postflight (p < 0.05) that was unaccompanied by a change in supine P(ET)CO(2). The decrease in MCA MFV that occurred during HUT in both groups preflight (p < 0.05) was accentuated only in the OI group postflight, particularly during the final 30 s of HUT (p < 0.05). However, this accentuated decrease in MCA MFV was not correlated to the greater decrease in P(ET)CO(2) during the same period (R = 0.20, p = 0.42). Although cerebral vascular resistance (CVR) also increased in the OI group during the last 30 s of HUT postflight (p < 0.05), the dynamic autoregulatory gain was not simultaneously changed. Therefore, we conclude that in the OI individuals, parabolic flight was associated with cerebral hypoperfusion following a paradoxical augmentation of CVR by a mechanism that was not related to changes in autoregulation nor strictly to changes in P(ET)CO(2).

  11. 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......, the capillaries in the germinal matrix are not supported by firm glial structures. Arterial pressure rises are therefore likely to be responsible for germinal matrix haemorrhage in the premature neonate, and the risk of haemorrhage probably diminishes as autoregulation of cerebral blood-flow is...

  12. Multiresolution analysis of pathological changes in cerebral venous dynamics in newborn mice with intracranial hemorrhage: adrenorelated vasorelaxation

    International Nuclear Information System (INIS)

    Intracranial hemorrhage (ICH) is the major problem of modern neonatal intensive care. Abnormalities of cerebral venous blood flow (CVBF) can play a crucial role in the development of ICH in infants. The mechanisms underlying these pathological processes remain unclear; however it has been established that the activation of the adrenorelated vasorelaxation can be an important reason. Aiming to reach a better understanding of how the adrenodependent relaxation of cerebral veins contributes to the development of ICH in newborns, we study here the effects of pharmacological stimulation of adrenorelated dilation of the sagittal sinus by isoproterenol on the cerebral venous hemodynamics. Our study is performed in newborn mice at different stages of ICH using the laser speckle contrast imaging and wavelet analysis of the vascular dynamics of CVBF. We show that the dilation of the sagittal sinus with the decreased velocity of blood flow presides to the stress-induced ICH in newborn mice. These morphofunctional vascular changes are accompanied by an increased variance of the wavelet-coefficients in the areas of endothelial and non-endothelial (KATP-channels activity of vascular muscle) sympathetic components of the CVBF variability. Changes in the cerebral venous hemodynamics at the latent stage of ICH are associated with a high responsiveness of the sagittal sinus to isoproterenol quantifying by wavelet-coefficients related to a very slow region of the frequency domain. The obtained results certify that a high activation of the adrenergic-related vasodilatory responses to severe stress in newborn mice can be one of the important mechanisms underlying the development of ICH. Thus, the venous insufficiency with the decreased blood outflow from the brain associated with changes in the endothelial and the sympathetic components of CVBF-variability can be treated as prognostic criteria for the risk of ICH during the first days after birth. (paper)

  13. In-vitro investigation of cerebral-perfusion effects of a rotary blood pump installed in the descending aorta.

    Science.gov (United States)

    Rezaienia, Mohammad Amin; Paul, Gordon; Avital, Eldad; Rahideh, Akbar; Rothman, Martin Terry; Korakianitis, Theodosios

    2016-06-14

    This study describes use of a cardiovascular simulator to replicate the hemodynamic responses of the cerebrovascular system with a mechanical circulatory support device operating in the descending aorta. To do so, a cerebral autoregulation unit was developed which replicates the dilation and constriction of the native cerebrovascular resistance system and thereby regulates the cerebral flow rate within defined limits. The efficacy of the replicated autoregulation mechanism was investigated by introducing a number of step alterations in mean aortic pressure and monitoring the cerebral flow. The steady responses of the cerebral flow to changes in mean aortic pressure were in good agreement with clinical data. Next, a rotary pump, modeling a mechanical circulatory support device, was installed in the descending aorta and the hemodynamic responses of the cerebral system were investigated over a wide range of pump operating conditions. Insertion of a mechanical circulatory support device in the descending aorta presented an improved cardiac output as a result of afterload reduction. It was observed that the primary drop in cerebral flow, caused by the pump in the descending aorta, was compensated over the course of five seconds due to a gradual decrease in cerebrovascular resistance. The experimental results suggest that the implantation of a mechanical circulatory support device in the descending aorta, a less invasive procedure than typical mechanical circulatory support implantation, will not have an adverse effect on the cognitive function, provided that the cerebral autoregulation is largely unimpaired. PMID:27155746

  14. Dominant negative autoregulation limits steady-state repression levels in gene networks.

    Science.gov (United States)

    Semsey, Szabolcs; Krishna, Sandeep; Erdossy, János; Horváth, Péter; Orosz, László; Sneppen, Kim; Adhya, Sankar

    2009-07-01

    Many transcription factors repress transcription of their own genes. Negative autoregulation has been shown to reduce cell-cell variation in regulatory protein levels and speed up the response time in gene networks. In this work we examined transcription regulation of the galS gene and the function of its product, the GalS protein. We observed a unique operator preference of the GalS protein characterized by dominant negative autoregulation. We show that this pattern of regulation limits the repression level of the target genes in steady states. We suggest that transcription factors with dominant negative autoregulation are designed for regulating gene expression during environmental transitions. PMID:19429616

  15. 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

    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......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....... Autoregulation was classified as impaired if Vmean increased by >10% per 30 mm Hg increase in MAP and if no lower limit of autoregulation was identified by the computer program; otherwise, autoregulation was classified as preserved. MAIN RESULTS: Initially, Vmean increased from a median value of 46 cm/sec (range...

  16. 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...

  17. Double-wavelet approach to study frequency and amplitude modulation in renal autoregulation

    DEFF Research Database (Denmark)

    Sosnovtseva, Olga; Pavlov, A.N.; Mosekilde, Erik;

    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 doubl...

  18. Dynamic Gene Expression in the Human Cerebral Cortex Distinguishes Children from Adults

    OpenAIRE

    Sterner, Kirstin N.; Weckle, Amy; Chugani, Harry T.; Tarca, Adi L.; Sherwood, Chet C.; Hof, Patrick R; Kuzawa, Christopher W.; Boddy, Amy M.; Abbas, Asad; Raaum, Ryan L.; Grégoire, Lucie; Lipovich, Leonard; Grossman, Lawrence I; Uddin, Monica; Goodman, Morris

    2012-01-01

    In comparison with other primate species, humans have an extended juvenile period during which the brain is more plastic. In the current study we sought to examine gene expression in the cerebral cortex during development in the context of this adaptive plasticity. We introduce an approach designed to discriminate genes with variable as opposed to uniform patterns of gene expression and found that greater inter-individual variance is observed among children than among adults. For the 337 tran...

  19. Original Research: Sickle cell anemia and pediatric strokes: Computational fluid dynamics analysis in the middle cerebral artery.

    Science.gov (United States)

    Rivera, Christian P; Veneziani, Alessandro; Ware, Russell E; Platt, Manu O

    2016-04-01

    Children with sickle cell anemia (SCA) have a high incidence of strokes, and transcranial Doppler (TCD) identifies at-risk patients by measuring blood velocities in large intracerebral arteries; time-averaged mean velocities greater than 200 cm/s confer high stroke risk and warrant therapeutic intervention with blood transfusions. Our objective was to use computational fluid dynamics to alter fluid and artery wall properties, to simulate scenarios causative of significantly elevated arterial blood velocities. Two-dimensional simulations were created and increasing percent stenoses were created in silico, with their locations varied among middle cerebral artery (MCA), internal carotid artery (ICA), and anterior cerebral artery (ACA). Stenoses placed in the MCA, ICA, or ACA generated local increases in velocity, but not sufficient to reach magnitudes > 200 cm/s, even up to 75% stenosis. Three-dimensional reconstructions of the MCA, ICA, and ACA from children with SCA were generated from magnetic resonance angiograms. Using finite element method, blood flow was simulated with realistic velocity waveforms to the ICA inlet. Three-dimensional reconstructions revealed an uneven, internal arterial wall surface in children with SCA and higher mean velocities in the MCA up to 145 cm/s compared to non-SCA reconstructions. There were also greater areas of flow recirculation and larger regions of low wall shear stress. Taken together, these bumps on the internal wall of the cerebral arteries could create local flow disturbances that, in aggregate, could elevate blood velocities in SCA. Identifying cellular causes of these microstructures as adhered blood cells or luminal narrowing due to endothelial hyperplasia induced by disturbed flow would provide new targets to treat children with SCA. The preliminary qualitative results provided here point out the critical role of 3D reconstruction of patient-specific vascular geometries and provide qualitative insight to complex

  20. Malignant cerebral swelling following cranioplasty.

    Science.gov (United States)

    Honeybul, S; Damodaran, O; Lind, C R P; Lee, G

    2016-07-01

    Over the past few years there have been a number of case reports and small cohort studies that have described so called "malignant" cerebral swelling following an uneventful cranioplasty procedure. The pathophysiology remains to be established however it has been suggested that it may be related to a combination of failure of autoregulation and the use of closed vacuum suction drainage. The current study presents three further patients who had had a decompressive hemicraniectomy for ischaemic stroke. If decompressive craniectomy is utilised in the management of neurological emergencies, close attention and wider reporting of this type of complication is required not only to focus attention on possible management strategies, but also to determine which patients are at most risk of this devastating complication. PMID:27189792

  1. Cerebral Hypoxia

    Science.gov (United States)

    ... Enhancing Diversity Find People About NINDS NINDS Cerebral Hypoxia Information Page Synonym(s): Hypoxia, Anoxia Table of Contents ( ... Trials Organizations Publicaciones en Español What is Cerebral Hypoxia? Cerebral hypoxia refers to a condition in which ...

  2. The effect of training in an interactive dynamic stander on ankle dorsiflexion and gross motor function in children with cerebral palsy

    DEFF Research Database (Denmark)

    Curtis, Derek John; Bencke, Jesper; Mygind, Bente

    2014-01-01

    OBJECTIVE: To study the effect of active stretching of ankle plantarflexors using an interactive dynamic stander in children with cerebral palsy (CP). METHODS: Six children in Gross Motor Function Classification System classes I-III, aged 4-10 years, trained intensive active dorsiflexion in an in...

  3. Noninvasive xenon-133 measurements of cerebral blood flow using stationary detectors compared with dynamic emission tomography

    DEFF Research Database (Denmark)

    Schroeder, T; Vorstrup, S; Lassen, N A;

    1986-01-01

    asymmetry in the middle cerebral artery territory shown with the tomograph. As illustrated by a case history, the nontomographic CBF unit used in this study may provide reliable and useful information in patients with occlusive cerebrovascular disease by performing repeated CBF studies and challenging the...... the stationary detectors yielded somewhat lower CBF values than did emission tomography. Considering the side-to-side asymmetry, an excellent correlation was obtained. Using the initial slope index, the stationary detectors revealed quantitatively 83% of the interhemispheric asymmetry and 63% of the...

  4. Quantitative comparison of hemodynamics in simulated and 3D angiography models of cerebral aneurysms by use of computational fluid dynamics.

    Science.gov (United States)

    Saho, Tatsunori; Onishi, Hideo

    2015-07-01

    In this study, we evaluated hemodynamics using simulated models and determined how cerebral aneurysms develop in simulated and patient-specific models based on medical images. Computational fluid dynamics (CFD) was analyzed by use of OpenFOAM software. Flow velocity, stream line, and wall shear stress (WSS) were evaluated in a simulated model aneurysm with known geometry and in a three-dimensional angiographic model. The ratio of WSS at the aneurysm compared with that at the basilar artery was 1:10 in simulated model aneurysms with a diameter of 10 mm and 1:18 in the angiographic model, indicating similar tendencies. Vortex flow occurred in both model aneurysms, and the WSS decreased in larger model aneurysms. The angiographic model provided accurate CFD information, and the tendencies of simulated and angiographic models were similar. These findings indicate that hemodynamic effects are involved in the development of aneurysms. PMID:25911446

  5. A dynamic concept of middle cerebral artery occlusion and cerebral infarction in the acute state based on interpreting severe hyperemia as a sign of embolic migration

    DEFF Research Database (Denmark)

    Olsen, T S; Lassen, N A

    1984-01-01

    The present study investigates the pathogenesis of focal cerebral hyperemia, its effect on brain tissue and discusses its pathophysiological and therapeutic importance in the light of interpreting severe hyperemia as a sign of arterial reopening probably due to embolic migration. Cerebral...... well as in non-infarcted tissue. Apparently, it is the severity of the initial ischemic episode and not the hyperemia that determines whether or not tissue necrosis develops. Interpreting severe hyperemia as a sign of arterial reopening and embolic migration (evidenced by partial reopening affecting...

  6. Measurements of regional cerebral blood flow (rCBF) using dynamic single-photon emission computed tomography (DSPECT): Definition of a generally acceptable normal range and follow-up checks after extracranial bypass surgery

    International Nuclear Information System (INIS)

    The usefulness of dynamic single-photon emission computed tomography was evaluated in 50 volunteers with unobtrusive cerebral findings, who were to provide the relevant standard values. It was found that the values measured were easily reproducible. Measurements in patients showing cerebrovascular disease that were carried out before and after extracranial bypass surgery did mostly not suggest any perceivable improvement of cerebral blood flow. In isolated cases the cerebral reserve was influenced favourably, as judged from measurements after administration of acetazolamide. (MBC)

  7. Clinical Neuroimaging of cerebral ischemia

    International Nuclear Information System (INIS)

    Notice points in clinical imaging of cerebral ischemia are reviewed. When cerebral blood flow is determined in acute stage of cerebral embolism (cerebral blood flow SPECT), it is important to find area of ischemic core and ischemic penumbra. When large cortex area is assigned to ischemic penumbra, thrombolytic therapy is positively adapted, but cautious correspondence is necessary when ischemic core is recognized. DWI is superior in the detection of area equivalent to ischemic core of early stage, but, in imaging of area equivalent to ischemic penumbra, perfusion image or distribution image of cerebral blood volume (CBV) by MRI need to be combined. Luxury perfusion detected by cerebral blood flow SPECT in the cases of acute cerebral embolism suggests vascular recanalization, but a comparison with CT/MRI and continuous assessment of cerebral circulation dynamics were necessary in order to predict brain tissue disease (metabolic abnormality). In hemodynamic cerebral ischemia, it is important to find stage 2 equivalent to misery perfusion by quantification of cerebral blood flow SPECT. Degree of diaschisis can indicate seriousness of brain dysfunction for lacuna infarct. Because cerebral circulation reserve ability (perfusion pressure) is normal in all areas of the low cerebral blood flow by diaschisis mechanism, their areas are easily distinguished from those of hemodynamic cerebral ischemia. (K.H.)

  8. 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.

  9. Tuberculoma cerebral Cerebral tuberculoma

    OpenAIRE

    ELIZABETH CLARA BARROSO; TÂNIA REGINA BRÍGIDO DE OLIVEIRA; ANA MARIA DANTAS DO AMARAL; VALÉRIA GÓES FERREIRA PINHEIRO; ANA LÚCIA DE OLIVEIRA SOUSA

    2002-01-01

    Relata-se o caso de paciente com crises convulsivas de início recente. A tomografia computadorizada cerebral evidenciou imagem sugestiva de lesão expansiva metastática frontoparietal direita. A investigação de tumor primário ou outra doença foi negativa e o exame histopatológico do tecido cerebral diagnosticou tuberculoma. As convulsões foram controladas com a associação de hidantoína 300mg/dia ao esquema específico, utilizado por 18 meses. A tuberculose do sistema nervoso central representa ...

  10. Real-time imaging reveals the dynamics of leukocyte behaviour during experimental cerebral malaria pathogenesis.

    Directory of Open Access Journals (Sweden)

    Saparna Pai

    2014-07-01

    Full Text Available During experimental cerebral malaria (ECM mice develop a lethal neuropathological syndrome associated with microcirculatory dysfunction and intravascular leukocyte sequestration. The precise spatio-temporal context in which the intravascular immune response unfolds is incompletely understood. We developed a 2-photon intravital microscopy (2P-IVM-based brain-imaging model to monitor the real-time behaviour of leukocytes directly within the brain vasculature during ECM. Ly6C(hi monocytes, but not neutrophils, started to accumulate in the blood vessels of Plasmodium berghei ANKA (PbA-infected MacGreen mice, in which myeloid cells express GFP, one to two days prior to the onset of the neurological signs (NS. A decrease in the rolling speed of monocytes, a measure of endothelial cell activation, was associated with progressive worsening of clinical symptoms. Adoptive transfer experiments with defined immune cell subsets in recombinase activating gene (RAG-1-deficient mice showed that these changes were mediated by Plasmodium-specific CD8(+ T lymphocytes. A critical number of CD8(+ T effectors was required to induce disease and monocyte adherence to the vasculature. Depletion of monocytes at the onset of disease symptoms resulted in decreased lymphocyte accumulation, suggesting reciprocal effects of monocytes and T cells on their recruitment within the brain. Together, our studies define the real-time kinetics of leukocyte behaviour in the central nervous system during ECM, and reveal a significant role for Plasmodium-specific CD8(+ T lymphocytes in regulating vascular pathology in this disease.

  11. 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...

  12. Dynamic changes of excitatory amino acid receptors in the rat hippocampus following transient cerebral ischemia

    International Nuclear Information System (INIS)

    The changes in excitatory amino acid receptor ligand binding induced by transient cerebral ischemia were studied in the rat hippocampal subfields. Ten minutes of ischemia was induced by common carotid artery occlusion combined with hypotension, and the animals were allowed variable periods of recovery ranging from 1 day to 4 weeks. The binding of 3H-AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) to quisqualate receptors, 3H-kainic acid (KA) to kainate receptors, and 3H-glutamate to N-methyl-D-aspartate (NMDA) receptors as determined by quantitative autoradiography. One week following ischemia the CA1 region of the hippocampus displayed a severe (90%) dendrosomatic lesion with preservation of presynaptic terminals. This was associated with a 60% decrease in AMPA binding and a 25% decrease in glutamate binding to NMDA receptors. At 4 weeks postischemia, both AMPA and NMDA sites were greatly reduced. Although the dentate gyrus granule cells are resistant to an ischemic insult of this magnitude, this region showed marked changes in receptor binding. One week following ischemia, the AMPA and NMDA binding decreased by approximately 40 and 20%, respectively. Following 2 weeks of recovery, the NMDA binding was not significantly different from control level, while the AMPA binding remained depressed up to 4 weeks postischemia. The high density of KA binding sites in the inner molecular layer of the dentate gyrus was unaffected by the ischemic insult, despite an extensive degeneration of cells in the hilus of dentate gyrus which projects glutamatergic afferents to this area

  13. Bidirectional Contrast agent leakage correction of dynamic susceptibility contrast (DSC)-MRI improves cerebral blood volume estimation and survival prediction in recurrent glioblastoma treated with bevacizumab.

    OpenAIRE

    Ab, KL; Boxerman, JL; Lai, A.; Nghiemphu, PL; Pope, WB; Cloughesy, TF; Ellingson, BM

    2016-01-01

    To evaluate a leakage correction algorithm for T1 and T2* artifacts arising from contrast agent extravasation in dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) that accounts for bidirectional contrast agent flux and compare relative cerebral blood volume (CBV) estimates and overall survival (OS) stratification from this model to those made with the unidirectional and uncorrected models in patients with recurrent glioblastoma (GBM).We determined median rCBV within contras...

  14. Cerebral Palsy

    Science.gov (United States)

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

  15. Cerebral Atrophy

    Science.gov (United States)

    ... Alzheimer’s disease, Pick’s disease, and fronto-temporal dementia cerebral palsy , in which lesions (damaged areas) may impair motor ... lead to cerebral atrophy. NIH Patient Recruitment for Cerebral Atrophy Clinical Trials ... by: Office of Communications and Public Liaison National Institute of Neurological Disorders ...

  16. Human cerebral circulation. Positron emission tomography studies

    International Nuclear Information System (INIS)

    We reviewed the literature on human cerebral circulation and oxygen metabolism, as measured by positron emission tomography (PET), with respect to normal values and of regulation of cerebral circulation. A multicenter study in Japan showed that between-center variations in cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) values were not considerably larger than the corresponding within-center variations. Overall mean±SD values in cerebral cortical regions of normal human subjects were as follows: CBF=44.4±6.5 ml/100 ml/min; CBV=3.8±0.7 ml/100 ml; OEF=0.44±0.06; CMRO2=3.3±0.5 ml/100 ml/min (11 PET centers, 70 subjects). Intrinsic regulation of cerebral circulation involves several factors. Autoregulation maintains CBF in response to changes in cerebral perfusion pressure; chemical factors such as PaCO2 affect cerebral vascular tone and alter CBF; changes in neural activity cause changes in cerebral energy metabolism and CBF; neurogenic control of CBF occurs by sympathetic innervation. Regional differences in vascular response to changes in PaCO2 have been reported, indicating regional differences in cerebral vascular tone. Relations between CBF and CBV during changes in PaCO2 and during changes in neural activity were in good agreement with Poiseuille's law. The mechanisms of vascular response to neural activation and deactivation were independent on those of responses to PaCO2 changes. CBV in a brain region is the sum of three components: arterial, capillary and venous blood volumes. It has been reported that the arterial blood volume fraction is approximately 30% in humans and that changes in human CBV during changes in PaCO2 are caused by changes in arterial blood volume without changes in venous blood volume. These findings should be considered in future studies of the pathophysiology of cerebrovascular diseases. (author) 136 refs

  17. Dynamic susceptibility contrast-enhanced MRI evaluation of cerebral intraventricular tumors: preliminary results.

    OpenAIRE

    Holveck, A.; Grand, Sylvie; Boini, Stéphane; Kirchin, Miles; Le Bas, Jean-François; Dietemann, Jean-Louis; Bracard, Serge; Kremer, Stéphane

    2010-01-01

    International audience INTRODUCTION: The aims of the present study were to determine the perfusion characteristics of several types of intraventricular tumors and to evaluate the usefulness of dynamic contrast-enhanced MRI in making the differential diagnosis. METHODS: A total of 28 patients with intraventricular tumors (five meningiomas, five papillomas, three ependymomas, four subependymomas, seven central neurocytomas, two subependymal giant cell astrocytomas and two metastases) underwe...

  18. Reduced short term adaptation to robot generated dynamic environment in children affected by Cerebral Palsy

    OpenAIRE

    Di Rosa Giuseppe; Morasso Pietro; Frascarelli Flaminia; Masia Lorenzo; Petrarca Maurizio; Castelli Enrico; Cappa Paolo

    2011-01-01

    Abstract Background It is known that healthy adults can quickly adapt to a novel dynamic environment, generated by a robotic manipulandum as a structured disturbing force field. We suggest that it may be of clinical interest to evaluate to which extent this kind of motor learning capability is impaired in children affected by cerebal palsy. Methods We adapted the protocol already used with adults, which employs a velocity dependant viscous field, and compared the performance of a group of sub...

  19. 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 mod...

  20. Clinical value of a computer system for data acquisition, processing, and display of cerebral dynamic studies

    International Nuclear Information System (INIS)

    Although the digital computer has had limited utility in nuclear medicine to date, it has proven of value as a source of information for future improvements. We have demonstrated that camera resolving time is currently not a significant problem for brain imaging. Investigations on the effect of rotation of the patient's head have emphasized the need for caution in isolated interpretation of numerical data. Camera nonuniformities may introduce disturbing image artifacts. If nonuniformity of response were reduced to the level of 5 percent, then one could probably delete this function by the computer since the computer normalization programs developed to date are not entirely satisfactory. Current dynamic brain studies could be improved by increasing photon yield. Static images are not primarily photon limited, but differ from problems of camera nonuniformity. (U.S.)

  1. DNA methylation in the human cerebral cortex is dynamically regulated throughout the life span and involves differentiated neurons.

    Directory of Open Access Journals (Sweden)

    Kimberly D Siegmund

    Full Text Available The role of DNA cytosine methylation, an epigenetic regulator of chromatin structure and function, during normal and pathological brain development and aging remains unclear. Here, we examined by MethyLight PCR the DNA methylation status at 50 loci, encompassing primarily 5' CpG islands of genes related to CNS growth and development, in temporal neocortex of 125 subjects ranging in age from 17 weeks of gestation to 104 years old. Two psychiatric disease cohorts--defined by chronic neurodegeneration (Alzheimer's or lack thereof (schizophrenia--were included. A robust and progressive rise in DNA methylation levels across the lifespan was observed for 8/50 loci (GABRA2, GAD1, HOXA1, NEUROD1, NEUROD2, PGR, STK11, SYK typically in conjunction with declining levels of the corresponding mRNAs. Another 16 loci were defined by a sharp rise in DNA methylation levels within the first few months or years after birth. Disease-associated changes were limited to 2/50 loci in the Alzheimer's cohort, which appeared to reflect an acceleration of the age-related change in normal brain. Additionally, methylation studies on sorted nuclei provided evidence for bidirectional methylation events in cortical neurons during the transition from childhood to advanced age, as reflected by significant increases at 3, and a decrease at 1 of 10 loci. Furthermore, the DNMT3a de novo DNA methyl-transferase was expressed across all ages, including a subset of neurons residing in layers III and V of the mature cortex. Therefore, DNA methylation is dynamically regulated in the human cerebral cortex throughout the lifespan, involves differentiated neurons, and affects a substantial portion of genes predominantly by an age-related increase.

  2. Flow Instability Detected by High-Resolution Computational Fluid Dynamics in Fifty-Six Middle Cerebral Artery Aneurysms.

    Science.gov (United States)

    Varble, Nicole; Xiang, Jianping; Lin, Ning; Levy, Elad; Meng, Hui

    2016-06-01

    Recent high-resolution computational fluid dynamics (CFD) studies have detected persistent flow instability in intracranial aneurysms (IAs) that was not observed in previous in silico studies. These flow fluctuations have shown incidental association with rupture in a small aneurysm dataset. The aims of this study are to explore the capabilities and limitations of a commercial cfd solver in capturing such velocity fluctuations, whether fluctuation kinetic energy (fKE) as a marker to quantify such instability could be a potential parameter to predict aneurysm rupture, and what geometric parameters might be associated with such fluctuations. First, we confirmed that the second-order discretization schemes and high spatial and temporal resolutions are required to capture these aneurysmal flow fluctuations. Next, we analyzed 56 patient-specific middle cerebral artery (MCA) aneurysms (12 ruptured) by transient, high-resolution CFD simulations with a cycle-averaged, constant inflow boundary condition. Finally, to explore the mechanism by which such flow instabilities might arise, we investigated correlations between fKE and several aneurysm geometrical parameters. Our results show that flow instabilities were present in 8 of 56 MCA aneurysms, all of which were unruptured bifurcation aneurysms. Statistical analysis revealed that fKE could not differentiate ruptured from unruptured aneurysms. Thus, our study does not lend support to these flow instabilities (based on a cycle-averaged constant inflow as opposed to peak velocity) being a marker for rupture. We found a positive correlation between fKE and aneurysm size as well as size ratio. This suggests that the intrinsic flow instability may be associated with the breakdown of an inflow jet penetrating the aneurysm space. PMID:27109451

  3. Tuberculoma cerebral Cerebral tuberculoma

    Directory of Open Access Journals (Sweden)

    ELIZABETH CLARA BARROSO

    2002-01-01

    Full Text Available Relata-se o caso de paciente com crises convulsivas de início recente. A tomografia computadorizada cerebral evidenciou imagem sugestiva de lesão expansiva metastática frontoparietal direita. A investigação de tumor primário ou outra doença foi negativa e o exame histopatológico do tecido cerebral diagnosticou tuberculoma. As convulsões foram controladas com a associação de hidantoína 300mg/dia ao esquema específico, utilizado por 18 meses. A tuberculose do sistema nervoso central representa 5-15% das formas extrapulmonares e é reconhecida como de alta letalidade. Apresentação tumoral como a relatada é rara, particularmente em imunocompetentes. Quando tratada, pode ter bom prognóstico e deve entrar sempre no diagnóstico diferencial de massas cerebrais.It is reported a case of a previously healthy man with seizures of sudden onset. A contrast head computerized tomogram (CT showed a right frontoparietal expanding lesion suggesting to be metastatic. No prior disease was found on investigation. The histologic exam of the brain revealed tuberculoma. The seizures were controlled with Hidantoin 300 mg/day and antituberculosis chemotherapy for 18 months. Central nervous system tuberculosis (5-15% of the extrapulmonary forms is highly lethal. The case reported herein is specially rare in immunocompetent patients. It may have good prognosis and should be considered in the differential diagnosis of brain tumours.

  4. Cerebral hemodynamics in moyamoya disease

    International Nuclear Information System (INIS)

    Rebuild-up phenomenon, an electroencephalographic pathological finding in moyamoya disease, was evaluated in the context of dynamic changes in cerebral circulation after hyperventilation. Sequential functional angiography after hyperventilation, measurement of cerebral blood flow (CBF) by the outflow method, and Kr-81m single photon emission tomography were employed for clarification of the sequential dynamic changes in cerebral circulation after hyperventilation. In most cases there was a persistent decrease in CBF even after arterial carbon dioxide tension (PaCO2) had been normalized, which suggests that the response of the cerebral circulation to the changes in PaCO2 is delayed. Moreover, this feature was most prominent in the superficial layer of the cerebrum. For the most part, coincidence and synchronization were documented between rebuild-up and the delayed response of the cerebral circulation. These findings indicate that the delayed CBF response to hyperventilation contributes pathogenetically to rebuild-up in moyamoya disease. (author)

  5. Hyperbaric oxygen treatment induces dynamic ATPase activity changes in the rat brain following transient global cerebral ischemia-reperfusion

    Institute of Scientific and Technical Information of China (English)

    Shiming Xu; Hongjuan Wang; Tongnan Gu; Xiuyan Zhou; Rui Chen

    2008-01-01

    BACKGROUND: Energy depletion, induced by ischemia or hypoxia, is one of the first events in neuronal injury. OBJECTIVE: To investigate the dynamic changes of Na+-K+-ATPase and Ca2+-ATPase activity in the rat brain following transient global cerebral ischemia-reperfusion (IR), as well as the effects of hyperbaric oxygen (HBO) treatment. DESIGN, TIME AND SETTING: A randomized and controlled animal study was performed in the Department of Biochemistry and Molecular Biology, Capital Medical University between February and December 2006. MATERIALS: Clean-grade, female, Sprague Dawley rats were provided by the Animal Research Department of Capital Medical University (License number: SYXK11-00-0047). Na+-K+-ATPase and Ca2+-ATPase kits were provided by Nanjing Jiancheng Bioengineering Institute (Nanjing, China). A hyperbaric oxygen chamber (DWC150-300) was supplied by Shanghai 701 Medical Oxygen Chamber Factory (Shanghai, China). METHODS: Sixty-three rats were randomly divided into nine groups: sham operated group (sham-O) as control, groups of IR, and groups treated with hyperbaric oxygen (HBO) after IR. Animal from the IR and HBO groups were sacrificed after four different survival intervals of 6, 24, 48 and 96 hours, respectively. Each group consisted of seven rats. The rats of HBO groups were placed into the hyperbaric chamber. The HBO chamber was flushed with pure oxygen for 5 minutes, followed by a gradual rise in pressure over 5 minutes and stabilization at 0.2 MPa. Then, pure oxygen was supplied for 45 minutes in stabilized pressure, followed by gradually reduced pressure over 15 minutes. The rats of the 6-h HBO group were placed into the HBO chamber following reperfusion for 3 hours on the first day, which was repeated on three consecutive days, always at the same time. Rats in the sham-O group and IR group remained under normal atmospheric pressure. MAIN OUTCOME MEASURES: The Na+-K+-ATPase and Ca2+-ATPase activity in rat brain homogenate was detected by the

  6. Dynamic contrast-enhanced x-ray CT measurement of cerebral blood volume in a rabbit tumor model

    Science.gov (United States)

    Cenic, Aleksa; Lee, Ting-Yim; Craen, Rosemary A.; Gelb, Adrian W.

    1998-07-01

    Cerebral blood volume (CBV) is a major determinant of intracranial pressure (ICP). Hyperventilation is commonly employed to reduce raised ICP (e.g. in brain tumour patients) presumably through its effect on CBV. With the advent of slip- ring CT scanners, dynamic contrast-enhanced imaging allows for the measurement of CBV with high spatial resolution. Using a two-compartment model to characterize the distribution of X- ray contrast agent in the brain, we have developed a non- equilibrium CT method to measure CBV in normal and pathological regions. We used our method to investigate the effect of hyperventilation on CBV during propofol anaesthesia in rabbits with implanted brain tumours. Eight New Zealand White rabbits with implanted VX2 carcinoma brain tumours were studied. For each rabbit, regional CBV measurements were initially made at normocapnia (PaCO2 40 mmHg) and then at hyperventilation (PaCO2 25 mmHg) during propofol anaesthesia. The head was positioned such that a coronal image through the brain incorporated a significant cross-section of the brain tumour as well as a radial artery in a forelimb. Images at the rate of 1 per second were acquired for 2 minutes as Omnipaque 300 (1.5 ml/kg rabbit weight) was injected via a peripheral vein. In these CT images, regions of interest in the brain tissue (e.g. tumour, contra-lateral normal, and peri-tumoural) and the radial artery were drawn. For each region, the mean CT number in pre-contrast images was subtracted from the mean CT number in post-contrast images to produce either the tissue contrast concentration curve, or the arterial contrast concentration curve. Using our non- equilibrium analysis method based on a two-compartment model, regional CBV values were determined from the measured contrast concentration curves. From our study, the mean CBV values [+/- SD] in the tumour, peri-tumoural, and contra-lateral normal regions during normocapnia were: 5.47 plus or minus 1.97, 3.28 plus or minus 1.01, and 1

  7. Cerebral perfusion MR imaging using FAIR-HASTE in chronic carotid occlusive disease: comparison with dynamic susceptibility contrast-perfusion MR imaging.

    Directory of Open Access Journals (Sweden)

    Ida,Kentaro

    2006-08-01

    Full Text Available To determine the efficacy of flow-sensitive alternating inversion recovery using half-Fourier single-shot turbo spin-echo (FAIR-HASTE in detecting cerebral hypoperfusion in chronic carotid occlusive disease, we subjected 12 patients with various degrees of cervical internal carotid artery stenoses and/or occlusion (Stenosis group and 24 volunteers (Normal group to FAIR-HASTE. In addition, 10 out of 12 patients in the Stenosis group underwent dynamic susceptibility contrast-perfusion magnetic resonance imaging (DSC-pMRI before and after revascularization in the dominantly affected side. The absolute asymmetry indexes (AIs of both cerebral hemispheres in the Normal and Stenosis groups were compared in FAIR-HASTE. In addition, the AIs were compared with those in the Stenosis group before and after revascularization in both FAIR-HASTE and regional cerebral blood flow (rCBF, calculated with DSC-pMRI. A statistically significant difference was recognized between the AIs in the Normal and Stenosis groups (AI = 2.25 +- 1.92, 8.09 +- 4.60, respectively ; p < 0.0001. Furthermore, in the Stenosis group the AIs on both FAIR-HASTE (8.88 +- 4.93, 2.22 +- 1.79, respectively ; p = 0.0003 and rCBF (7.13 +- 3.57, 1.25 +- 1.33, respectively ; p = 0.0003 significantly decreased after revascularization. In the Stenosis group, before revascularization, signal intensity on both FAIR-HASTE and rCBF had a tendency to be lower in the dominantly affected side. FAIR-HASTE imaging was useful in the detection and evaluation of cerebral hypoperfusion in chronic occlusive carotid disease.

  8. Cerebral Palsy

    Science.gov (United States)

    ... 1 • 2 • 3 For Teens For Kids For Parents MORE ON THIS TOPIC Cerebral Palsy: Keith's Story Physical Therapy I Have Cerebral Palsy. Can I Babysit? Body Image and Self-Esteem Contact Us Print Resources Send to a friend ...

  9. 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.

  10. Heterogeneity of cerebral vasoreactivity in preterm infants supported by mechanical ventilation

    International Nuclear Information System (INIS)

    The reaction of cerebral blood flow to acute changes in arterial carbon dioxide pressure (PaCO2) and mean arterial blood pressure was determined in 57 preterm infants supported by mechanical ventilation (mean gestational age 30.1 weeks) during the first 48 hours of life. All infants had normal brain sonograms at the time of the investigation. In each infant, global cerebral blood flow was determined by xenon-133 clearance two to five times within a few hours at different levels of PaCO2. Changes in PaCO2 followed adjustments of the ventilator settings. Arterial oxygen pressure was intended to be kept constant, and mean arterial blood pressure fluctuated spontaneously between measurements. The data were analyzed by stepwise multiple regression, with changes in global cerebral blood flow, PaCO2, mean arterial blood pressure, and postnatal age or intracranial hemorrhage used as variables. In infants with persistently normal brain sonograms, the global cerebral blood flow-carbon dioxide reactivity was markedly lower during the first day of life (mean 11.2% to 11.8%/kPa PaCO2) compared with the second day of life (mean 32.6/kPa PaCO2), and pressure-flow autoregulation was preserved. Similarly, global cerebral blood flow-carbon dioxide reactivity and pressure-flow autoregulation were present in infants in whom mild intracranial hemorrhage developed after the study. In contrast, global cerebral blood flow reactivity to changes in PaCO2 and mean arterial blood pressure was absent in infants in whom ultrasonographic signs of severe intracranial hemorrhage subsequently developed. These infants also had about 20% lower global cerebral blood flow before hemorrhage, in comparison with infants whose sonograms were normal, a finding that suggests functional disturbances of cerebral blood flow regulation

  11. The Utility of Cerebral Blood Flow Assessment in TBI.

    Science.gov (United States)

    Akbik, Omar S; Carlson, Andrew P; Krasberg, Mark; Yonas, Howard

    2016-08-01

    Over the past few decades, intracranial monitoring technologies focused on treating and preempting secondary injury after traumatic brain injury (TBI) have experienced considerable growth. A physiological measure fundamental to the management of these patients is cerebral blood flow (CBF), which may be determined directly or indirectly. Direct measurement has proven difficult previously; however, invasive and non-invasive CBF monitors are now available. This article reviews the history of CBF measurements in TBI as well as the role of CBF in pathologies associated with TBI, such as cerebral autoregulation, hyperemia, and cortical spreading depression. The limitations of various CBF monitors are reviewed in order to better understand their role in TBI management. PMID:27315250

  12. Cerebral palsy.

    Science.gov (United States)

    Graham, H Kerr; Rosenbaum, Peter; Paneth, Nigel; Dan, Bernard; Lin, Jean-Pierre; Damiano, Diane L; Becher, Jules G; Gaebler-Spira, Deborah; Colver, Allan; Reddihough, Dinah S; Crompton, Kylie E; Lieber, Richard L

    2016-01-01

    Cerebral palsy is the most common cause of childhood-onset, lifelong physical disability in most countries, affecting about 1 in 500 neonates with an estimated prevalence of 17 million people worldwide. Cerebral palsy is not a disease entity in the traditional sense but a clinical description of children who share features of a non-progressive brain injury or lesion acquired during the antenatal, perinatal or early postnatal period. The clinical manifestations of cerebral palsy vary greatly in the type of movement disorder, the degree of functional ability and limitation and the affected parts of the body. There is currently no cure, but progress is being made in both the prevention and the amelioration of the brain injury. For example, administration of magnesium sulfate during premature labour and cooling of high-risk infants can reduce the rate and severity of cerebral palsy. Although the disorder affects individuals throughout their lifetime, most cerebral palsy research efforts and management strategies currently focus on the needs of children. Clinical management of children with cerebral palsy is directed towards maximizing function and participation in activities and minimizing the effects of the factors that can make the condition worse, such as epilepsy, feeding challenges, hip dislocation and scoliosis. These management strategies include enhancing neurological function during early development; managing medical co-morbidities, weakness and hypertonia; using rehabilitation technologies to enhance motor function; and preventing secondary musculoskeletal problems. Meeting the needs of people with cerebral palsy in resource-poor settings is particularly challenging. PMID:27188686

  13. Perfusion Pressure Cerebral Infarct (PPCI) trial - the importance of mean arterial pressure during cardiopulmonary bypass to prevent cerebral complications after cardiac surgery

    DEFF Research Database (Denmark)

    Vedel, Anne G; Holmgaard, Frederik; Rasmussen, Lars Simon;

    2016-01-01

    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...... 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...

  14. Cerebral hypoxia

    Science.gov (United States)

    ... the veins ( deep vein thrombosis ) Lung infections (pneumonia) Malnutrition When to Contact a Medical Professional Cerebral hypoxia ... References Bernat JL. Coma, vegetative state, and brain death. In: Goldman L, Schafer AI, eds. Goldman's Cecil ...

  15. Measurement of cerebral blood flow with 133Xe inhalation and dynamic single photon emission computer tomography. Normal values

    International Nuclear Information System (INIS)

    Cerebral blood flow was studied by 133Xe inhalation tomography in 25 healthy subjects. Mean age was 41 years and range 23-66 years. Mean hemispheric CBF at rest was 59.8 ml/100 g/min, and cerebellar flow 60.8 ml/100 g/min. The distribution of CBF values was skewed and approximated a log normal distribution. Estimated lower and upper normal reference range limits calculated as mean (log) = - 2 S.D. (log) were 47-74 ml/100 g/min. Women had approximately 5 ml/100 g/min higher CBF values than men, corresponding to the difference in hematocrit. Neither in men or women was there any tendency to age dependent reduction or increase in flow. In both sexes hemispheric regional CBF (rCBF) was asymmetric with higher flow values in the right cerebral hemisphere; particularly in the anterior distribution territory of the middle cerebral artery. Emotional activation as a consequence of the study conditions is assumed to be the cause of this observed asymmetry. Cerebellar flow was not assymetric. No significant difference in cerebellar or hemispheric CBF was found when a second study followed the first by 3-15 months, PCO2 correction of flow improved reproducibility. Acetazolamide responses are reported. (author)

  16. THE DYNAMICS OF LABILITY OF DIRECT CURRENT POTENTIALS OF THE BRAIN AND THE PSYCHOPHYSIOLOGY PARAMETERS IN THE 10-11 YEARS OLD CHILDREN WITH THE HETERO-TYPE CEREBRAL INTER-HEMISPHERES ASYMMETRY DURING SUSTAINED ATTENTION

    Directory of Open Access Journals (Sweden)

    I.A. Shimko

    2010-03-01

    Full Text Available The dynamics of direct current potentials of the brain was studied in the 10-11 years old children during sustained attention to successive presentation of series of Shulte tables. The examination was performed twice – before and after the series of training to speed reading. The gradual increase of direct current potentials during sustained attention was observed. The increase was more pronounced in the children with the left-type cerebral inter-hemispheres asymmetry, than in the children with the right-type cerebral inter-hemispheres asymmetry, moderate reaction to the loading. After the series of training to fast reading the increase of direct current potentials was reduced in both groups. This after training neurophysiological phenomenon was combined with the transformation of psychophysiological characteristics: reducing time of examination of Shulte tables and acceleration of speed of reading. It is suggested that the shifts of direct current potentials reflects the dynamics of the intensity of cerebral energy metabolism.

  17. 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

    in describing the dynamic pressure-flow relation is found to be important. Furthermore, the dependence of 1st-order kernel waveforms on the power level of broadband pressure forcing indicates the presence of nonlinear feedback (of sigmoid type) based on previously reported analysis of a class of...... nonlinear feedback systems....

  18. Cerebral Palsy (For Parents)

    Science.gov (United States)

    ... Story" 5 Things to Know About Zika & Pregnancy Cerebral Palsy KidsHealth > For Parents > Cerebral Palsy Print A A ... kids who are living with the condition. About Cerebral Palsy Cerebral palsy is one of the most common ...

  19. Autoregressive moving average (ARMA) model applied to quantification of cerebral blood flow using dynamic susceptibility contrast-enhanced magnetic resonance imaging

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate the feasibility of the autoregressive moving average (ARMA) model for quantification of cerebral blood flow (CBF) with dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSC-MRI) in comparison with deconvolution analysis based on singular value decomposition (DA-SVD). Using computer simulations, we generated a time-dependent concentration of the contrast agent in the volume of interest (VOI) from the arterial input function (AIF) modeled as a gamma-variate function under various CBFs, cerebral blood volumes and signal-to-noise ratios (SNRs) for three different types of residue function (exponential, triangular, and box-shaped). We also considered the effects of delay and dispersion in AIF. The ARMA model and DA-SVD were used to estimate CBF values from the simulated concentration-time curves in the VOI and AIFs, and the estimated values were compared with the assumed values. We found that the CBF value estimated by the ARMA model was more sensitive to the SNR and the delay in AIF than that obtained by DA-SVD. Although the ARMA model considerably overestimated CBF at low SNRs, it estimated the CBF more accurately than did DA-SVD at high SNRs for the exponential or triangular residue function. We believe this study will contribute to an understanding of the usefulness and limitations of the ARMA model when applied to quantification of CBF with DSC-MRI. (author)

  20. Dynamics of the brain: Mathematical models and non-invasive experimental studies

    Science.gov (United States)

    Toronov, V.; Myllylä, T.; Kiviniemi, V.; Tuchin, V. V.

    2013-10-01

    Dynamics is an essential aspect of the brain function. In this article we review theoretical models of neural and haemodynamic processes in the human brain and experimental non-invasive techniques developed to study brain functions and to measure dynamic characteristics, such as neurodynamics, neurovascular coupling, haemodynamic changes due to brain activity and autoregulation, and cerebral metabolic rate of oxygen. We focus on emerging theoretical biophysical models and experimental functional neuroimaging results, obtained mostly by functional magnetic resonance imaging (fMRI) and near-infrared spectroscopy (NIRS). We also included our current results on the effects of blood pressure variations on cerebral haemodynamics and simultaneous measurements of fast processes in the brain by near-infrared spectroscopy and a very novel functional MRI technique called magnetic resonance encephalography. Based on a rapid progress in theoretical and experimental techniques and due to the growing computational capacities and combined use of rapidly improving and emerging neuroimaging techniques we anticipate during next decade great achievements in the overall knowledge of the human brain.

  1. Perfusion measurements of the brain: using dynamic CT for the quantitative assessment of cerebral ischemia in acute stroke

    International Nuclear Information System (INIS)

    Objective: Perfusion CT has been successfully used as a functional imaging technique for the differential diagnosis of patients with hyperacute stroke. We investigated to what extent this technique can also be used for the quantitative assessment of cerebral ischemia. Methods and material: We studied linearity, spatial resolution and noise behaviour of cerebral blood flow (CBF) determination with computer simulations and phantom measurements. Statistical ROI based analysis of CBF images of a subset of 38 patients from a controlled clinical stroke study with currently more than 75 patients was done to check the power of relative cerebral blood flow (rCBF) values to predict definite infarction and ischemic penumbra. Classification was performed using follow-up CT and MR data. Results: Absolute CBF values were systematically underestimated, the degree depended on the cardiac output of the patients. Phantom measurements and simulations indicated very good linearity allowing reliable calculation of rCBF values. Infarct and penumbra areas in 19 patients receiving standard heparin therapy had mean rCBF values of 0.19 and 0.62, respectively. The corresponding values for 19 patients receiving local intraarterial fibrinolysis were 0.18 and 0.57. The difference between infarct and penumbra values was highly significant (P<0.0001) in both groups. No penumbra area was found with an rCBF value of less than 0.20. While in the heparin group only 25% of all areas with an rCBF between 0.20 and 0.35 survived, in the fibrinolytic group 61% of these areas could be saved (P<0.05). Conclusion: Perfusion CT is a fast and practical technique for routine clinical application. It provides substantial and important additional information for the selection of the optimal treatment strategy for patients with hyperacute stroke. Relative values of cerebral blood flow discriminate very well between areas of reversible and irreversible ischemia; an rCBF value of 0.20 appears to be a definite lower

  2. Clinical study of cardiogenic cerebral embolism

    International Nuclear Information System (INIS)

    In order to investigate the distribution of lesion size and to determine the background factors responsible for large infarcts, we examined CT findings in 88 consecutive patients with acute cardiogenic cerebral embolism of the internal carotid arterial system. Lesion size was determined by brain CT, and expressed as the 'infarct index'. The typical CT finding was a sharply marginated lesion in the cortex corresponding to the occluded arterial territory, accompanied by mass effect. Over half of the cases showed an infarct index of 20% or less. Most cases had small lesions, with substantially fewer cases having large infarcts. The lack of large infarcts was attributable to early recanalization of the occluded artery. Several background factors were implicated in the large infarcts, including elevated hematocrit, fibrinogen, arterial blood pressure, cardiothoracic ratio (as seen in chest X-rays), and a shortening of activated partial thromboplastin time (APTT). Factors implicated in the formation of a large embolus included increased blood viscosity and coagulability (caused by dehydration), and a hypertension-induced shift of the lower limit of autoregulation to a higher level. Further study is needed to determine whether such changes arise as the cause or the effect of a cerebral embolism. (author)

  3. Absolute quantification of cerebral blood flow in neurologically normal volunteers: dynamic-susceptibility contrast MRI-perfusion compared with computed tomography (CT)-perfusion.

    Science.gov (United States)

    Ziegelitz, Doerthe; Starck, Göran; Mikkelsen, Irene K; Tullberg, Mats; Edsbagge, Mikael; Wikkelsö, Carsten; Forssell-Aronson, Eva; Holtås, Stig; Knutsson, Linda

    2009-07-01

    To improve the reproducibility of arterial input function (AIF) registration and absolute cerebral blood flow (CBF) quantification in dynamic-susceptibility MRI-perfusion (MRP) at 1.5T, we rescaled the AIF by use of a venous output function (VOF). We compared CBF estimates of 20 healthy, elderly volunteers, obtained by computed tomography (CT)-perfusion (CTP) and MRP on two consecutive days. MRP, calculated without the AIF correction, did not result in any significant correlation with CTP. The rescaled MRP showed fair to moderate correlation with CTP for the central gray matter (GM) and the whole brain. Our results indicate that the method used for correction of partial volume effects (PVEs) improves MRP experiments by reducing AIF-introduced variance at 1.5T. PMID:19253361

  4. Acute ischemic cerebral attack

    Directory of Open Access Journals (Sweden)

    Franco-Garcia Samir

    2010-12-01

    Full Text Available 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 violent death in the world and the first of disability. Many risk factors favor the presentation of these events and some of them are susceptible of modification and therfore are objetives of primary prevention just as the control of diabetes, hypertension and the practice of healthy habits of life. The advances in the knowledge of the physiopatology, had taken to sustantial change in the nomenclature and management of ischemic ACS. Within these changes it was substituted the term cerebrovascular accident fo acute stroke, making emphasis in the key rol of a timely management with goals of time similiar to the acute coronary syndrome. It was redefined the time of acute ischemic attack to a one hour. Once stablished the cerebrovascular attack the semiology of symtoms with frecuency will led us make a topographic diagnosis of the in injury that joined to the cerebral TAC will allow us to exclude an hemorragic event and to start the treatment. In the management of these patients its essential the coordination of the differents teams of work, from the early recognition of symtoms on the part of patients andthe family, the rapid activation and response of emergency systems and the gearing of health care institutions. Are pillars of treatment: the abcde of reanimatiion, to avoid the hiperpirexis, the seizures, the hipoglicemy, the hiperglicemy, to achieve the thrombolysis in the first three hours of the begining of symtoms, to use antiplatelets, antithrombotic profilaxis

  5. Autoregulation of the stability operon of IncFII plasmid NR1.

    OpenAIRE

    Tabuchi, A; Min, Y N; Womble, D D; Rownd, R H

    1992-01-01

    The stb locus of IncFII plasmid NR1, which mediates stable inheritance of the plasmid, is composed of an essential cis-acting DNA site located upstream from two tandem genes that encode essential stability proteins. The two tandem genes, stbA and stbB, are transcribed as an operon from promoter PAB. Using PAB-lacZ gene fusions, it was found that the stb operon is autoregulated. A low-copy-number stb+ plasmid introduced into the same cell with the PAB-lacZ fusion plasmid repressed beta-galacto...

  6. Design of power auto-regulating system's high reliability controller for 200 MW nuclear heating reactor

    International Nuclear Information System (INIS)

    The paper mainly introduces power auto-regulating system's high reliability controller for 200 MW Nuclear Heating Reactor. The controller is implemented with excellent performance 16 bit single chip microcomputer 8097. Master controller and 10 digit samplers are blocked. Each and every block's hardware is identical. These blocks communicate each other through 8 bit BUS and operate synchronously by united clock and reset signal and are designed with three redundancies. The identity comparison principle through two-out-of three is also introduced. The test proves that designing scheme is feasible

  7. Tuberculoma cerebral

    OpenAIRE

    BARROSO ELIZABETH CLARA; OLIVEIRA TÂNIA REGINA BRÍGIDO DE; AMARAL ANA MARIA DANTAS DO; PINHEIRO VALÉRIA GÓES FERREIRA; SOUSA ANA LÚCIA DE OLIVEIRA

    2002-01-01

    Relata-se o caso de paciente com crises convulsivas de início recente. A tomografia computadorizada cerebral evidenciou imagem sugestiva de lesão expansiva metastática frontoparietal direita. A investigação de tumor primário ou outra doença foi negativa e o exame histopatológico do tecido cerebral diagnosticou tuberculoma. As convulsões foram controladas com a associação de hidantoína 300mg/dia ao esquema específico, utilizado por 18 meses. A tuberculose do sistema nervoso central representa ...

  8. C-type period-doubling transition in nephron autoregulation

    DEFF Research Database (Denmark)

    Laugesen, Jakob Lund; Mosekilde, Erik; Holstein-Rathlou, Niels-Henrik

    2011-01-01

    The functional units of the kidney, called nephrons, utilize mechanisms that allow the individual nephron to regulate the incoming blood flow in response to fluctuations in the arterial pressure. This regulation tends to be unstable and to generate self-sustained oscillations, period-doubling bif......The functional units of the kidney, called nephrons, utilize mechanisms that allow the individual nephron to regulate the incoming blood flow in response to fluctuations in the arterial pressure. This regulation tends to be unstable and to generate self-sustained oscillations, period......-doubling bifurcations, mode-locking and other nonlinear dynamic phenomena in the tubular pressures and flows. Using a simplified nephron model, the paper examines how the regulatory mechanisms react to an external periodic variation in arterial pressure near a region of resonance with one of the internally generated...

  9. Cerebral versus systemic hemodynamics during graded orthostatic stress in humans

    Science.gov (United States)

    Levine, B. D.; Giller, C. A.; Lane, L. D.; Buckey, J. C.; Blomqvist, C. G.

    1994-01-01

    BACKGROUND: Orthostatic syncope is usually attributed to cerebral hypoperfusion secondary to systemic hemodynamic collapse. Recent research in patients with neurocardiogenic syncope has suggested that cerebral vasoconstriction may occur during orthostatic hypotension, compromising cerebral autoregulation and possibly contributing to the loss of consciousness. However, the regulation of cerebral blood flow (CBF) in such patients may be quite different from that of healthy individuals, particularly when assessed during the rapidly changing hemodynamic conditions associated with neurocardiogenic syncope. To be able to interpret the pathophysiological significance of these observations, a clear understanding of the normal responses of the cerebral circulation to orthostatic stress must be obtained, particularly in the context of the known changes in systemic and regional distributions of blood flow and vascular resistance during orthostasis. Therefore, the specific aim of this study was to examine the changes that occur in the cerebral circulation during graded reductions in central blood volume in the absence of systemic hypotension in healthy humans. We hypothesized that cerebral vasoconstriction would occur and CBF would decrease due to activation of the sympathetic nervous system. We further hypothesized, however, that the magnitude of this change would be small compared with changes in systemic or skeletal muscle vascular resistance in healthy subjects with intact autoregulation and would be unlikely to cause syncope without concomitant hypotension. METHODS AND RESULTS: To test this hypothesis, we studied 13 healthy men (age, 27 +/- 7 years) during progressive lower body negative pressure (LBNP). We measured systemic flow (Qc is cardiac output; C2H2 rebreathing), regional forearm flow (FBF; venous occlusion plethysmography), and blood pressure (BP; Finapres) and calculated systemic (SVR) and forearm (FVR) vascular resistances. Changes in brain blood flow were

  10. Cerebral Arteriosclerosis

    Science.gov (United States)

    ... the brain can cause a hemorrhagic stroke. Both types of stroke can be fatal. Cerebral arteriosclerosis is also related to a condition known as vascular dementia, in which small, symptom-free strokes cause cumulative damage and death to neurons (nerve cells) in the brain. Personality changes in ...

  11. An automated sleep-state classification algorithm for quantifying sleep timing and sleep-dependent dynamics of electroencephalographic and cerebral metabolic parameters

    Directory of Open Access Journals (Sweden)

    Rempe MJ

    2015-09-01

    Full Text Available Michael J Rempe,1,2 William C Clegern,2 Jonathan P Wisor2 1Mathematics and Computer Science, Whitworth University, Spokane, WA, USA; 2College of Medical Sciences and Sleep and Performance Research Center, Washington State University, Spokane, WA, USAIntroduction: Rodent sleep research uses electroencephalography (EEG and electromyography (EMG to determine the sleep state of an animal at any given time. EEG and EMG signals, typically sampled at >100 Hz, are segmented arbitrarily into epochs of equal duration (usually 2–10 seconds, and each epoch is scored as wake, slow-wave sleep (SWS, or rapid-eye-movement sleep (REMS, on the basis of visual inspection. Automated state scoring can minimize the burden associated with state and thereby facilitate the use of shorter epoch durations.Methods: We developed a semiautomated state-scoring procedure that uses a combination of principal component analysis and naïve Bayes classification, with the EEG and EMG as inputs. We validated this algorithm against human-scored sleep-state scoring of data from C57BL/6J and BALB/CJ mice. We then applied a general homeostatic model to characterize the state-dependent dynamics of sleep slow-wave activity and cerebral glycolytic flux, measured as lactate concentration.Results: More than 89% of epochs scored as wake or SWS by the human were scored as the same state by the machine, whether scoring in 2-second or 10-second epochs. The majority of epochs scored as REMS by the human were also scored as REMS by the machine. However, of epochs scored as REMS by the human, more than 10% were scored as SWS by the machine and 18 (10-second epochs to 28% (2-second epochs were scored as wake. These biases were not strain-specific, as strain differences in sleep-state timing relative to the light/dark cycle, EEG power spectral profiles, and the homeostatic dynamics of both slow waves and lactate were detected equally effectively with the automated method or the manual scoring

  12. Simultaneous monitoring of static and dynamic intracranial pressure parameters from two separate sensors in patients with cerebral bleeds: comparison of findings

    Directory of Open Access Journals (Sweden)

    Eide Per

    2012-09-01

    Full Text Available Abstract Background We recently reported that in an experimental setting the zero pressure level of solid intracranial pressure (ICP sensors can be altered by electrostatics discharges. Changes in the zero pressure level would alter the ICP level (mean ICP; whether spontaneous changes in mean ICP happen in clinical settings is not known. This can be addressed by comparing the ICP parameters level and waveform of simultaneous ICP signals. To this end, we retrieved our recordings in patients with cerebral bleeds wherein the ICP had been recorded simultaneously from two different sensors. Materials and Methods: During a time period of 10 years, 17 patients with cerebral bleeds were monitored with two ICP sensors simultaneously; sensor 1 was always a solid sensor while Sensor 2 was a solid -, a fluid - or an air-pouch sensor. The simultaneous signals were analyzed with automatic identification of the cardiac induced ICP waves. The output was determined in consecutive 6-s time windows, both with regard to the static parameter mean ICP and the dynamic parameters (mean wave amplitude, MWA, and mean wave rise time, MWRT. Differences in mean ICP, MWA and MWRT between the two sensors were determined. Transfer functions between the sensors were determined to evaluate how sensors reproduce the ICP waveform. Results Comparing findings in two solid sensors disclosed major differences in mean ICP in 2 of 5 patients (40%, despite marginal differences in MWA, MWRT, and linear phase magnitude and phase. Qualitative assessment of trend plots of mean ICP and MWA revealed shifts and drifts of mean ICP in the clinical setting. The transfer function analysis comparing the solid sensor with either the fluid or air-pouch sensors revealed more variable transfer function magnitude and greater differences in the ICP waveform derived indices. Conclusions Simultaneous monitoring of ICP using two solid sensors may show marked differences in static ICP but close to identity

  13. Changes in mean cerebral blood flow velocity during cognitive task-induced cerebral fatigue in high performance fighter pilots

    Institute of Scientific and Technical Information of China (English)

    Yongsheng Chen

    2008-01-01

    BACKGROUND: Several studies have demonstrated that sustained cognitive tasks can induce cognitive fatigue and that the mean cerebral blood flow velocity changes in some cerebral regions during cerebral fatigue. OBJECTIVE: To dynamically monitor the changes in mean cerebral blood flow velocity in different brain regions of high performance fighter pilots during mental arithmetic tasks and consecutive performance tasks. DESIGN, TIME AND SETTING: The present neurophysiological trial, based on controlled observation, was performed at the Laboratory of Neurophysiology, Institute of Aviation Medicine, Air Force of China between January 2003 and December 2005. PARTICIPANTS: Forty-five males, high performance fighter pilots, averaging (27.6 ± 2.5) years, were recruited for this study. METHODS: The mean cerebral blood flow velocity in the anterior cerebral artery, middle cerebral artery, and posterior cerebral artery of subjects was dynamically tested using transcranial Doppler during 5- hour mental arithmetic tasks and during 5- hour consecutive performance tasks. The neurobehavioral ability index was analyzed throughout each trial according to the number of correct responses, false responses, and lost responses. Simultaneously, cerebral cognitive fatigue-induced lethargy was assessed by the Stanford Sleepiness Scale. MAIN OUTCOME MEASURES: Changes in mean cerebral blood flow velocity in the anterior cerebral artery, middle cerebral artery, and posterior cerebral artery; neurobehavioral ability index of mental arithmetic and consecutive performance tasks; Stanford Sleepiness Scale scores. RESULTS: During mental arithmetic tasks, the mean cerebral blood flow velocity in the anterior cerebral artery increased during hour 2 and decreased after hour 4. There was no significant change in mean cerebral blood flow velocity in the middle cerebral artery and posterior cerebral artery. During hour 4, cerebral cognitive fatigue was observed and, simultaneously, Stanford Sleepiness

  14. Erythropoietin--en ny terapi ved cerebral iskaemi?

    DEFF Research Database (Denmark)

    Kalialis, Louise Vennegaard; Olsen, Niels Vidiendal

    2003-01-01

    Erythropoietin (EPO) is a cytokine which is commonly associated with its central role in erythropoiesis. The clinical applications of the recombinant hormone are currently restricted to the treatment of anemia in renal failure and cancer. Recent studies, however, have suggested a new role for EPO...... administration of recombinant EPO exerts neuroprotection in models of stroke. The mechanisms appear to involve an upregulation of specific anti-apoptotic and anti-inflammatory pathways. In addition, neurotrophic and angiogenetic effects of EPO may contribute in a long latency protection. Interestingly, also...... systemic administration of recombinant EPO ameliorates neuronal damage after brain ischaemia, and prevents the loss of autoregulation of cerebral blood flow following experimental subarachnoid haemorrhage. Recombinant human EPO is a safe and non-toxic drug, and clinical studies are currently investigating...

  15. 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 ...

  16. Cerebral hemodynamics in aging : the interplay between blood pressure, cerebral perfusion, and dementia

    OpenAIRE

    Claassen, J.A.H.R.

    2008-01-01

    Advances in measurement techniques have made it possible to study dynamic changes in brain blood flow. Transcranial Doppler ultrasonography measures changes in cerebral blood flow-velocity in the larger cerebral arteries (e.g. the middle cerebral artery). Near infrared spectroscopy records changes in brain cortical tissue concentrations of hemoglobin. These techniques are non-invasive, and can be performed with the subject in supine, sitting or standing position. Together with photoplethysmog...

  17. 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.......5 micromol.kg(-1).min(-1) and then returned to approximately 9 micromol.kg(-1).min(-1), while plasma glucose concentration increased from approximately 4.5 to 5.3 mM, accompanied by a rise in plasma insulin concentration. Over 50% of the galactose infused was accounted for in blood glucose and hepatic...

  18. Cerebral oxygenation and hyperthermia

    Directory of Open Access Journals (Sweden)

    AnthonyRichardBain

    2014-03-01

    Full Text Available Hyperthermia is associated with marked reductions in cerebral blood flow (CBF. Increased distribution of cardiac output to the periphery, increases in alveolar ventilation and resultant hypocapnia each contribute to the fall in CBF during passive hyperthermia; however, their relative contribution remains a point of contention, and probably depends on the experimental condition (e.g. posture and degree of hyperthermia. The hyperthermia-induced hyperventilatory response reduces arterial CO2 pressure (PaCO2 causing cerebral vasoconstriction and subsequent reductions in flow. During supine passive hyperthermia, the majority of recent data indicate that reductions in PaCO2 may be the primary, if not sole, culprit for reduced CBF. On the other hand, during more dynamic conditions (e.g. hemorrhage or orthostatic challenges, an inability to appropriately decrease peripheral vascular conductance presents a condition whereby adequate cerebral perfusion pressure may be compromised secondary to reductions in systemic blood pressure. Although studies have reported maintenance of pre-frontal cortex oxygenation (assessed by near-infrared spectroscopy during exercise and severe heat stress, the influence of cutaneous blood flow is known to contaminate this measure. This review discusses the governing mechanisms associated with changes in CBF and oxygenation during moderate to severe (i.e. 1.0°C to 2.0°C increase in body core temperature levels of hyperthermia. Future research directions are provided.

  19. THE DYNAMICS OF LABILITY OF DIRECT CURRENT POTENTIALS OF THE BRAIN AND THE PSYCHOPHYSIOLOGY PARAMETERS IN THE 10-11 YEARS OLD CHILDREN WITH THE HETERO-TYPE CEREBRAL INTER-HEMISPHERES ASYMMETRY DURING SUSTAINED ATTENTION

    OpenAIRE

    I.A. Shimko; О.А. Аndreev

    2010-01-01

    The dynamics of direct current potentials of the brain was studied in the 10-11 years old children during sustained attention to successive presentation of series of Shulte tables. The examination was performed twice – before and after the series of training to speed reading. The gradual increase of direct current potentials during sustained attention was observed. The increase was more pronounced in the children with the left-type cerebral inter-hemispheres asymmetry, than in the c...

  20. Controlling Spatial Heat and Light Distribution by Using Photothermal Enhancing Auto-Regulated Liposomes (PEARLs).

    Science.gov (United States)

    Ng, Kenneth K; Weersink, Robert A; Lim, Liang; Wilson, Brian C; Zheng, Gang

    2016-08-16

    Photothermal therapy (PTT) is enhanced by the use of nanoparticles with a large optical absorption at the treatment wavelength. However, this comes at the cost of higher light attenuation that results in reduced depth of heating as well as larger thermal gradients, leading to potential over- and under-treatment in the target tissue. These limitations can be overcome by using photothermal enhancing auto-regulating liposomes (PEARLs), based on thermochromic J-aggregate forming dye-lipid conjugates that reversibly alter their absorption above a predefined lipid phase-transition temperature. Under irradiation by near-infrared light, deeper layers of the target tissue revert to the intrinsic optical absorption, halting the temperature rise and enabling greater light penetration and heat generation at depth. This effect is demonstrated in both nanoparticle solutions and in gel phantoms containing the nanoparticles. PMID:27411830

  1. Effect of interscalene anaesthesia on cerebral oxygen saturation.

    Science.gov (United States)

    Soeding, P F; Currigan, D A; Mamo, Y; Hoy, G

    2016-05-01

    Interscalene blockade (ISB) is commonly associated with Horner's syndrome, indicating spread of injectate to the cervical sympathetic chain. Cervical sympathetic nerve activity (SNA) is believed to influence cerebral autoregulation, and a decrease in sympathetic tone may alter cerebral blood flow (CBF). This study investigated whether ISB influenced CBF in patients undergoing shoulder surgery. Patients (n=30) scheduled for elective shoulder arthroscopy were recruited. Cerebral oxygen saturation (ScO2) of the left and right frontal cortices was continuously measured during ISB administration, sedation and anaesthetic induction. Baseline ScO2 was similar in blocked and unblocked sides (74 ± 5% and 73 ± 5% respectively, P=0.70). ScO2 decreased with sedation (-3 ± 3% and -4 ± 3%, P=0.93), and increased with pre-oxygenation and general anaesthesia (P blocked and unblocked sides (P=0.18), or any difference between right- or left-sided ISB. ISB is not associated with an increase in CBF as indicated by ScO2, despite the presence of Horner's syndrome. PMID:27246935

  2. Cerebral palsy

    International Nuclear Information System (INIS)

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

  3. Cerebral malaria.

    Science.gov (United States)

    Postels, Douglas G; Birbeck, Gretchen L

    2013-01-01

    Malaria, the most significant parasitic disease of man, kills approximately one million people per year. Half of these deaths occur in those with cerebral malaria (CM). The World Health Organization (WHO) defines CM as an otherwise unexplained coma in a patient with malarial parasitemia. Worldwide, CM occurs primarily in African children and Asian adults, with the vast majority (greater than 90%) of cases occurring in children 5 years old or younger in sub-Saharan Africa. The pathophysiology of the disease is complex and involves infected erythrocyte sequestration, cerebral inflammation, and breakdown of the blood-brain barrier. A recently characterized malarial retinopathy is visual evidence of Plasmodium falciparum's pathophysiological processes occurring in the affected patient. Treatment consists of supportive care and antimalarial administration. Thus far, adjuvant therapies have not been shown to improve mortality rates or neurological outcomes in children with CM. For those who survive CM, residual neurological abnormalities are common. Epilepsy, cognitive impairment, behavioral disorders, and gross neurological deficits which include motor, sensory, and language impairments are frequent sequelae. Primary prevention strategies, including bed nets, vaccine development, and chemoprophylaxis, are in varied states of development and implementation. Continuing efforts to find successful primary prevention options and strategies to decrease neurological sequelae are needed. PMID:23829902

  4. Analytic Models of Oxygen and Nutrient Diffusion, Metabolism Dynamics, and Architecture Optimization in Three-Dimensional Tissue Constructs with Applications and Insights in Cerebral Organoids.

    Science.gov (United States)

    McMurtrey, Richard J

    2016-03-01

    Diffusion models are important in tissue engineering as they enable an understanding of gas, nutrient, and signaling molecule delivery to cells in cell cultures and tissue constructs. As three-dimensional (3D) tissue constructs become larger, more intricate, and more clinically applicable, it will be essential to understand internal dynamics and signaling molecule concentrations throughout the tissue and whether cells are receiving appropriate nutrient delivery. Diffusion characteristics present a significant limitation in many engineered tissues, particularly for avascular tissues and for cells whose viability, differentiation, or function are affected by concentrations of oxygen and nutrients. This article seeks to provide novel analytic solutions for certain cases of steady-state and nonsteady-state diffusion and metabolism in basic 3D construct designs (planar, cylindrical, and spherical forms), solutions that would otherwise require mathematical approximations achieved through numerical methods. This model is applied to cerebral organoids, where it is shown that limitations in diffusion and organoid size can be partially overcome by localizing metabolically active cells to an outer layer in a sphere, a regionalization process that is known to occur through neuroglial precursor migration both in organoids and in early brain development. The given prototypical solutions include a review of metabolic information for many cell types and can be broadly applied to many forms of tissue constructs. This work enables researchers to model oxygen and nutrient delivery to cells, predict cell viability, study dynamics of mass transport in 3D tissue constructs, design constructs with improved diffusion capabilities, and accurately control molecular concentrations in tissue constructs that may be used in studying models of development and disease or for conditioning cells to enhance survival after insults like ischemia or implantation into the body, thereby providing a

  5. In-vivo optical imaging and spectroscopy of cerebral hemodynamics

    Science.gov (United States)

    Zhou, Chao

    Functional optical imaging techniques, such as diffuse optical imaging and spectroscopy and laser speckle imaging (LSI), were used in research and clinical settings to measure cerebral hemodynamics. In this thesis, theoretical and experimental developments of the techniques and their in-vivo applications ranging from small animals to adult humans are demonstrated. Near infrared diffuse optical techniques non-invasively measure hemoglobin concentrations, blood oxygen saturation (diffuse reflectance spectroscopy, DRS) and blood flow (diffuse correlation spectroscopy, DCS) in deep tissues, e.g. brain. A noise model was derived for DCS measurements. Cerebral blood flow (CBF) measured with DCS was validated with arterial-spin-labeling MRI. Three-dimensional CBF tomography was obtained during cortical spreading depression from a rat using the optimized diffuse correlation tomographic method. Cerebral hemodynamics in newborn piglets after traumatic brain injury were continuously monitored optically for six hours to demonstrate the feasibility of using diffuse optical techniques as bedside patient monitors. Cerebral autoregulation in piglets and human stroke patients was demonstrated to be non-invasively assessable via the continuous DCS measurement. Significant differences of CBF responses to head-of-bead maneuvers were observed between the peri- and contra-infarct hemispheres in human stroke patients. A significant portion of patient population showed paradoxical CBF responses, indicating the importance of individualized stroke management. The development of a speckle noise model revealed the source of noise for LSI. LSI was then applied to study the acute functional recovery of the rat brain following transient brain ischemia. The spatial and temporal cerebral blood flow responses to functional stimulation were statistically quantified. The area of activation, and the temporal response to stimulation were found significantly altered by the ischemic insult, while the

  6. 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.

  7. Effects of head-down-tilt bed rest on cerebral hemodynamics during orthostatic stress

    Science.gov (United States)

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

    1997-01-01

    Our aim was to determine whether the adaptation to simulated microgravity (microG) impairs regulation of cerebral blood flow (CBF) during orthostatic stress and contributes to orthostatic intolerance. Twelve healthy subjects (aged 24 +/- 5 yr) underwent 2 wk of -6 degrees head-down-tilt (HDT) bed rest to simulate hemodynamic changes that occur when humans are exposed to microG. CBF velocity in the middle cerebral artery (transcranial Doppler), blood pressure, cardiac output (acetylene rebreathing), and forearm blood flow were measured at each level of a ramped protocol of lower body negative pressure (LBNP; -15, -30, and -40 mmHg x 5 min, -50 mmHg x 3 min, then -10 mmHg every 3 min to presyncope) before and after bed rest. Orthostatic tolerance was assessed by using the cumulative stress index (CSI; mmHg x minutes) for the LBNP protocol. After bed rest, each individual's orthostatic tolerance was reduced, with the group CSI decreased by 24% associated with greater decreases in cardiac output and greater increases in systemic vascular resistance at each level of LBNP. Before bed rest, mean CBF velocity decreased by 14, 10, and 45% at -40 mmHg, -50 mmHg, and maximal LBNP, respectively. After bed rest, mean velocity decreased by 16% at -30 mmHg and by 21, 35, and 39% at -40 mmHg, -50 mmHg, and maximal LBNP, respectively. Compared with pre-bed rest, post-bed-rest mean velocity was less by 11, 10, and 21% at -30, -40, and -50 mmHg, respectively. However, there was no significant difference at maximal LBNP. We conclude that cerebral autoregulation during orthostatic stress is impaired by adaptation to simulated microG as evidenced by an earlier and greater fall in CBF velocity during LBNP. We speculate that impairment of cerebral autoregulation may contribute to the reduced orthostatic tolerance after bed rest.

  8. Cerebral venous thrombosis in childhood

    Energy Technology Data Exchange (ETDEWEB)

    Huisman, T.A.G.M.; Martin, E.; Willi, U.V. [Dept. of Diagnostic Imaging and Radiology, University Children' s Hospital Zurich (Switzerland); Holzmann, D. [Dept. of Otorhinolaryngology, University Children' s Hospital Zurich, Zurich (Switzerland)

    2001-09-01

    This was a retrospective study to determine different etiologies of cerebral venous thrombosis (CVT) in childhood and to correlate extent and location of thrombosis with the etiology and the age of the child as well as the final outcome. In addition, the radiologic approach is discussed. This was a retrospective analysis of 19 children with CVT. The children were examined by contrast-enhanced dynamic CT. Radiologic findings were correlated with the etiology of CVT. Cerebral venous thrombosis is not as infrequent in children as has been thought. Cerebral venous thrombosis in children can occur due to trauma (n=9), infections (n=7), or coagulation disorders (n=3). Extent and location of thrombosis, as well as complications, final outcome, and therapy, depend on the etiology. Computed tomography remains a valuable primary imaging modality in the diagnosis of CVT in the acutely injured or diseased child. (orig.)

  9. Cerebral venous thrombosis in childhood

    International Nuclear Information System (INIS)

    This was a retrospective study to determine different etiologies of cerebral venous thrombosis (CVT) in childhood and to correlate extent and location of thrombosis with the etiology and the age of the child as well as the final outcome. In addition, the radiologic approach is discussed. This was a retrospective analysis of 19 children with CVT. The children were examined by contrast-enhanced dynamic CT. Radiologic findings were correlated with the etiology of CVT. Cerebral venous thrombosis is not as infrequent in children as has been thought. Cerebral venous thrombosis in children can occur due to trauma (n=9), infections (n=7), or coagulation disorders (n=3). Extent and location of thrombosis, as well as complications, final outcome, and therapy, depend on the etiology. Computed tomography remains a valuable primary imaging modality in the diagnosis of CVT in the acutely injured or diseased child. (orig.)

  10. Dynamic SPECT with Xe-133: regional cerebral blood flow in patients with unilaterial cerebrovascular disease: concise communication

    International Nuclear Information System (INIS)

    To validate xenon-133 dynamic single photon emission tomography (SPECT) clinically, 74 patients were examined. Strictly unilateral cerebrovascular disease was confirmed in 47 patients by clinical history and by transmission computerized tomography (TCT) and contrast angiography. Twenty-seven were excluded, considered normal. SPECT flow maps were evaluated visually (against TCT) or by automated region of interest (ROI) techniques. Visually, low-flow areas were detected twice as frequently in SPECT as areas of low density in TCT. In reversible episodes, sensitivity of AF alone was significantly below the sensitivity of combined evaluation of flow and ratio

  11. 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; Olsen, Jørn; Pedersen, Klaus M; Laurberg, Peter

    2013-01-01

    BACKGROUND: Placental transport of iodide is required for fetal thyroid hormone production. The sodium iodide symporter (NIS) mediates active iodide transport into the thyroid and the lactating mammary gland and is also present in placenta. NIS is competitively inhibited by thiocyanate from...... 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......: Maternal smoking increased the degree of iodine deficiency in parallel in the mother and the fetus, as reflected by increased Tg levels. However, placental iodide transport seemed unaffected despite high thiocyanate levels, suggesting that thiocyanate-insensitive iodide transporters alternative to NIS are...

  12. Cerebral cysticercosis

    International Nuclear Information System (INIS)

    Two cases of histologically proven cerebral cysticercosis are presented. In both cases subcutaneous tissue nodules, a rare feature, were present. Several disease patterns are apparent - meningeal, parenchymatous and ventricular, spinal cord lesions and mixed patterns. Epilepsy is by far the major presenting symptom of cysticercosis, which in turn plays a significant role in the causation of adult-onset epilepsy in Blacks. Despite its drawbacks, the haemag-glutination inhibition test remains the most satisfactory serological method at present available for the diagnosis of cysticercosis; it is positive in up to 85% of cases of proven cysticercosis. With the advent of computed tomography many cases of unsuspected cysticercosis (symptomatic or asymptomatic) are being discovered

  13. Non-ionizing radiofrequency electromagnetic waves traversing the head can be used to detect cerebrovascular autoregulation responses

    OpenAIRE

    Oziel, M.; M. Hjouj; Gonzalez, C.A.; Lavee, J.; Rubinsky, B

    2016-01-01

    Monitoring changes in non-ionizing radiofrequency electromagnetic waves as they traverse the brain can detect the effects of stimuli employed in cerebrovascular autoregulation (CVA) tests on the brain, without contact and in real time. CVA is a physiological phenomenon of importance to health, used for diagnosis of a number of diseases of the brain with a vascular component. The technology described here is being developed for use in diagnosis of injuries and diseases of the brain in rural an...

  14. Investigating cerebral oedema using poroelasticity.

    Science.gov (United States)

    Vardakis, John C; Chou, Dean; Tully, Brett J; Hung, Chang C; Lee, Tsong H; Tsui, Po-Hsiang; Ventikos, Yiannis

    2016-01-01

    Cerebral oedema can be classified as the tangible swelling produced by expansion of the interstitial fluid volume. Hydrocephalus can be succinctly described as the abnormal accumulation of cerebrospinal fluid (CSF) within the brain which ultimately leads to oedema within specific sites of parenchymal tissue. Using hydrocephalus as a test bed, one is able to account for the necessary mechanisms involved in the interaction between oedema formation and cerebral fluid production, transport and drainage. The current state of knowledge about integrative cerebral dynamics and transport phenomena indicates that poroelastic theory may provide a suitable framework to better understand various diseases. In this work, Multiple-Network Poroelastic Theory (MPET) is used to develop a novel spatio-temporal model of fluid regulation and tissue displacement within the various scales of the cerebral environment. The model is applied through two formats, a one-dimensional finite difference - Computational Fluid Dynamics (CFD) coupling framework, as well as a two-dimensional Finite Element Method (FEM) formulation. These are used to investigate the role of endoscopic fourth ventriculostomy in alleviating oedema formation due to fourth ventricle outlet obstruction (1D coupled model) in addition to observing the capability of the FEM template in capturing important characteristics allied to oedema formation, like for instance in the periventricular region (2D model). PMID:26749338

  15. Cerebral blood volume calculated by dynamic susceptibility contrast-enhanced perfusion MR imaging: preliminary correlation study with glioblastoma genetic profiles.

    Directory of Open Access Journals (Sweden)

    Inseon Ryoo

    Full Text Available PURPOSE: To evaluate the usefulness of dynamic susceptibility contrast (DSC enhanced perfusion MR imaging in predicting major genetic alterations in glioblastomas. MATERIALS AND METHODS: Twenty-five patients (M:F = 13∶12, mean age: 52.1±15.2 years with pathologically proven glioblastoma who underwent DSC MR imaging before surgery were included. On DSC MR imaging, the normalized relative tumor blood volume (nTBV of the enhancing solid portion of each tumor was calculated by using dedicated software (Nordic TumorEX, NordicNeuroLab, Bergen, Norway that enabled semi-automatic segmentation for each tumor. Five major glioblastoma genetic alterations (epidermal growth factor receptor (EGFR, phosphatase and tensin homologue (PTEN, Ki-67, O6-methylguanine-DNA methyltransferase (MGMT and p53 were confirmed by immunohistochemistry and analyzed for correlation with the nTBV of each tumor. Statistical analysis was performed using the unpaired Student t test, ROC (receiver operating characteristic curve analysis and Pearson correlation analysis. RESULTS: The nTBVs of the MGMT methylation-negative group (mean 9.5±7.5 were significantly higher than those of the MGMT methylation-positive group (mean 5.4±1.8 (p = .046. In the analysis of EGFR expression-positive group, the nTBVs of the subgroup with loss of PTEN gene expression (mean: 10.3±8.1 were also significantly higher than those of the subgroup without loss of PTEN gene expression (mean: 5.6±2.3 (p = .046. Ki-67 labeling index indicated significant positive correlation with the nTBV of the tumor (p = .01. CONCLUSION: We found that glioblastomas with aggressive genetic alterations tended to have a high nTBV in the present study. Thus, we believe that DSC-enhanced perfusion MR imaging could be helpful in predicting genetic alterations that are crucial in predicting the prognosis of and selecting tailored treatment for glioblastoma patients.

  16. Effects of midazolam on cerebral blood flow in human volunteers

    International Nuclear Information System (INIS)

    The effects of intravenously administered midazolam on cerebral blood flow were evaluated in eight healthy volunteers using the 133Xe 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

  17. Application of Wavelet-Based Tools to Study the Dynamics of Biological Processes

    DEFF Research Database (Denmark)

    Pavlov, A. N.; Makarov, V. A.; Mosekilde, Erik;

    2006-01-01

    The article makes use of three different examples (sensory information processing in the rat trigeminal complex, intracellular interaction in snail neurons and multimodal dynamics in nephron autoregulation) to demonstrate how modern approaches to time-series analysis based on the wavelet-transfor......The article makes use of three different examples (sensory information processing in the rat trigeminal complex, intracellular interaction in snail neurons and multimodal dynamics in nephron autoregulation) to demonstrate how modern approaches to time-series analysis based on the wavelet...

  18. Cerebral hemometabolism: from isolated measurements to monitoring and therapy

    Directory of Open Access Journals (Sweden)

    Julio Cruz

    1993-03-01

    Full Text Available An overview is presented on historical and multivariate aspects of cerebral hemometabolism. This involves a full multivariate approach, from blood pressure to cerebral metabolism. From isolated measurements, to monitoring and management, a comprehensive overview of cerebral hemometabolism is addressed, from its inception to current days, up to a new concept, the cerebral hemodynamic reserve. A multivariate functional diagram is proposed, to summarize the multivariate interrelationships of cerebral hemometabolism. A generic proposition is mode for studies of truly normal cerebral hemometabolism in children, for subsequent clinical applications. Another proposition is made for multivariate cerebral hemometabolic monitoring, in a broad variety of circumstances of predominantly global changes in intracranial dynamics, both in animal and clinical research.

  19. United Cerebral Palsy

    Science.gov (United States)

    ... Voices of UCP blog for the latest updates. United Cerebral Palsy UCP educates, advocates and provides support ... Our Partners Merz Logo Sprint Relay Copyright © 2015 United Cerebral Palsy 1825 K Street NW Suite 600 ...

  20. Cerebral palsy and epilepsy

    OpenAIRE

    Knežević-Pogančev Marija

    2010-01-01

    Introduction. Cerebral palsy is the most common cause of physical disability in early childhood. Epilepsy is known to have a high association with cerebral palsy. All types of epileptic seizures can be seen in patients with cerebral palsy. Complex partial and secondary generalized ones are the most frequent seizure types. In persons with cerebral palsy and mental retardation, the diagnosis of epilepsy presents unique difficulties. Generally they are not able to describe the epileptic ev...

  1. The effect of herbs on cerebral energy metabolism in cerebral ischemia-reperfusion mice

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Vascular dementia is one of the most familiar types of senile dementia. Over the past few years, the research on the damage of cerebral tissues after ischemia has become a focus. The factors and mechanism of cerebral tissue damage after ischemia are very complex. The handicap of energy metabolism is regarded as the beginning factor which leads to the damage of neurons, but its dynamic changes in ischemic area and its role during the process of neuronal damage are not very clear. There are few civil reports on using 31 P nuclear magnetic resonance instrument to explore the changes of cerebral energy metabolism in intravital animals. After exploring the influence of herbs on cerebral energy metabolism in ischemia-reperfusion mice, we came to the conclusion that herbs can improve the cerebral energy metabolism in ischemia-reperfusion mice.

  2. Propofol effect on cerebral oxygenation in children with congenital heart disease.

    Science.gov (United States)

    Fleck, Thilo; Schubert, Stephan; Ewert, Peter; Stiller, Brigitte; Nagdyman, Nicole; Berger, Felix

    2015-03-01

    Propofol is a short-acting, intravenously administered hypnotic agent which is used in procedural sedation in children. Propofol is known to decrease systemic vascular resistance, arterial blood pressure and can lead to desaturations and decreased systemic perfusion in children with cardiac shunting. This may result in a reduction in cerebral blood flow and oxygenation. Near-infrared spectroscopy (NIRS) can monitor cerebral tissue oxygenation in the frontal neocortex. The objective of our study was to measure the changes in cerebral oxygen and blood supply after Propofol infusion in children with congenital heart disease. Propofol infusion may reduce cerebral oxygenation in children with congenital heart disease. The study group consisted of 32 children (f:m = 18:14), with median age of 49 (5-112) months and median weight of 15 (5-34) kg. We performed NIRS derived continuous measurement of cerebral oxygenation and cardiac output using Electrical velocimetry for 5 min before and after sedation with Propofol (1-2 mg/kg i.v.) for cardiac catheterization. Simultaneously, non-invasive arterial blood pressure and transcutaneous oxygen saturation were measured. Propofol sedation led to a significant decrease in mean arterial pressure (79 ± 16 vs. 67 ± 12 mmHg) (p = 0.01) and cardiac index (3.2 ± 0.8 vs. 2.9 ± 0.6 ml/min/m(2)) (p = 0.03). In contrast, cerebral tissue oxygenation index, increased significantly from 57 ± 11 to 59 ± 10 % (p blood pressure. This may be caused by a decreased oxygen consumption of the sedated brain with intact cerebral auto-regulation. PMID:25311762

  3. The effects of healthy aging on cerebral hemodynamic responses to posture change

    International Nuclear Information System (INIS)

    Aging is associated with an increased incidence of orthostatic hypotension, impairment of the baroreceptor reflex and lower baseline cerebral blood flow. The effect of aging on cerebrovascular autoregulation, however, remains to be fully elucidated. We used a novel optical instrument to assess microvascular cerebral hemodynamics in the frontal lobe cortex of 60 healthy subjects ranging from ages 20–78. Diffuse correlation spectroscopy (DCS) and near-infrared spectroscopy (NIRS) were used to measure relative cerebral blood flow (rCBF), total hemoglobin concentration (THC), oxyhemoglobin concentration (HbO2) and deoxyhemoglobin concentration (Hb). Cerebral hemodynamics were monitored for 5 min at each of the following postures: head-of-bed 30°, supine, standing and supine. Supine-to-standing posture change caused significant declines in rCBF, THC and HbO2, and an increase in Hb, across the age continuum (p < 0.01). Healthy aging did not alter postural changes in frontal cortical rCBF (p = 0.23) and was associated with a smaller magnitude of decline in HbO2 (p < 0.05) during supine-to-standing posture change. We conclude that healthy aging does not alter postural changes in frontal cortical perfusion

  4. Renal Heme Oxygenase-1 Induction with Hemin Augments Renal Hemodynamics, Renal Autoregulation, and Excretory Function

    Science.gov (United States)

    Botros, Fady T.; Dobrowolski, Leszek; Navar, L. Gabriel

    2012-01-01

    Heme oxygenases (HO-1; HO-2) catalyze conversion of heme to free iron, carbon monoxide, and biliverdin/bilirubin. To determine the effects of renal HO-1 induction on blood pressure and renal function, normal control rats (n = 7) and hemin-treated rats (n = 6) were studied. Renal clearance studies were performed on anesthetized rats to assess renal function; renal blood flow (RBF) was measured using a transonic flow probe placed around the left renal artery. Hemin treatment significantly induced renal HO-1. Mean arterial pressure and heart rate were not different (115 ± 5 mmHg versus 112 ± 4 mmHg and 331 ± 16 versus 346 ± 10 bpm). However, RBF was significantly higher (9.1 ± 0.8 versus 7.0 ± 0.5 mL/min/g, P < 0.05), and renal vascular resistance was significantly lower (13.0 ± 0.9 versus 16.6 ± 1.4 [mmHg/(mL/min/g)], P < 0.05). Likewise, glomerular filtration rate was significantly elevated (1.4 ± 0.2 versus 1.0 ± 0.1 mL/min/g, P < 0.05), and urine flow and sodium excretion were also higher (18.9 ± 3.9 versus 8.2 ± 1.0 μL/min/g, P < 0.05 and 1.9 ± 0.6 versus 0.2 ± 0.1 μmol/min/g, P < 0.05, resp.). The plateau of the autoregulation relationship was elevated, and renal vascular responses to acute angiotensin II infusion were attenuated in hemin-treated rats reflecting the vasodilatory effect of HO-1 induction. We conclude that renal HO-1 induction augments renal function which may contribute to the antihypertensive effects of HO-1 induction observed in hypertension models. PMID:22518281

  5. Spectral analysis of systemic and cerebral cardiovascular variabilities in preterm infants: relationship with clinical risk index for babies (CRIB)

    International Nuclear Information System (INIS)

    Frequency spectrum analysis of circulatory signals has been proposed as a potential method for clinical risk assessment of preterm infants by previous studies. In this study, we examined the relationships between various spectral measures derived from systemic and cerebral cardiovascular variabilities and the clinical risk index for babies (CRIB II). Physiological data collected from 17 early low birth weight infants within 1–3 h after birth were analysed. Spectral and cross-spectral analyses were performed on heart rate variability, blood pressure variability and cerebral near-infrared spectroscopy measures such as oxygenated and deoxygenated haemoglobins (HbO2 and HHb) and tissue oxygenation index (TOI). In addition, indices related to cardiac baroreflex sensitivity and cerebral autoregulation were derived from the very low, low- and mid-frequency ranges (VLF, LF and MF). Moderate correlations with CRIB II were identified from mean arterial pressure (MAP) normalized MF power (r = 0.61, P = 0.009), LF MAP–HHb coherence (r = 0.64, P = 0.006), TOI VLF percentage power (r = 0.55, P = 0.023) and LF baroreflex gain (r = −0.61, P = 0.01 after logarithmic transformation), with the latter two parameters also highly correlated with gestational age (r = −0.75, P = 0.0005 and r = 0.70, P = 0.002, respectively). The relationships between CRIB II and various spectral measures of arterial baroreflex and cerebral autoregulation functions have provided further justification for these measures as possible markers of clinical risks and predictors of adverse outcome in preterm infants

  6. Isolation and Cannulation of Cerebral Parenchymal Arterioles.

    Science.gov (United States)

    Pires, Paulo W; Dabertrand, Fabrice; Earley, Scott

    2016-01-01

    Intracerebral parenchymal arterioles (PAs), which include parenchymal arterioles, penetrating arterioles and pre-capillary arterioles, are high resistance blood vessels branching out from pial arteries and arterioles and diving into the brain parenchyma. Individual PA perfuse a discrete cylindrical territory of the parenchyma and the neurons contained within. These arterioles are a central player in the regulation of cerebral blood flow both globally (cerebrovascular autoregulation) and locally (functional hyperemia). PAs are part of the neurovascular unit, a structure that matches regional blood flow to metabolic activity within the brain and also includes neurons, interneurons, and astrocytes. Perfusion through PAs is directly linked to the activity of neurons in that particular territory and increases in neuronal metabolism lead to an augmentation in local perfusion caused by dilation of the feed PA. Regulation of PAs differs from that of better-characterized pial arteries. Pressure-induced vasoconstriction is greater in PAs and vasodilatory mechanisms vary. In addition, PAs do not receive extrinsic innervation from perivascular nerves - innervation is intrinsic and indirect in nature through contact with astrocytic endfeet. Thus, data regarding contractile regulation accumulated by studies using pial arteries does not directly translate to understanding PA function. Further, it remains undetermined how pathological states, such as hypertension and diabetes, affect PA structure and reactivity. This knowledge gap is in part a consequence of the technical difficulties pertaining to PA isolation and cannulation. In this manuscript we present a protocol for isolation and cannulation of rodent PAs. Further, we show examples of experiments that can be performed with these arterioles, including agonist-induced constriction and myogenic reactivity. Although the focus of this manuscript is on PA cannulation and pressure myography, isolated PAs can also be used for

  7. Cerebral angiography in leptomeningitis and cerebritis

    International Nuclear Information System (INIS)

    This is a report of the cerebral angiographic findings in cases of meningitis and cerebritis. Fifty-nine patients, 38 of whom were under 1 year of age, underwent cerebral angiography by means of femoral catheterization. All the patients had signs of increased intracranial pressure, seizures, focal cerebral signs, positive transillumination of the head, and or abnormal brain scan findings. A few patients who did not respond to systemic antibiotics as was expected were also evaluated by means of cerebral angiography. The following characteristic angiographic findings were observed in 18 cases of active meningitis: (1) A hasy appearance around the arteries (halo formation) between the late arterial and capillary phases. (2) Narrowing of the arteries in the basal cistern. This sometimes extended to the peripheral arteries. (3) Irregular caliber following the narrowing of arteries (in few cases). (4) Circulation time so slow that veins could be seen in the late arterial phase. (5) Halo formation around the anterior chroidal artery and the clear appearance of the choroid plexus in the venous phase (when the infectious process reached the choroid plexus). Cerebritis could be identified on the angiograms by two signs: (1) local swelling of the brain (mainly the temporal lobe) and (2) staining around the veins without any abnormal signs in the arterial phase (laminar staining). In conclusion, angiography is a meaningful test by which to determine the phase of meningitis and cerebritis. These two conditions should be treated based on valid information obtained by means of CSF examinations and neuroradiological tests, especially CT scan and cerebral angiography. (author)

  8. Dopamine binds calmodulin during autoregulation of dopaminergic D2 receptor signaling through CaMKIIα-calmodulin complex.

    Science.gov (United States)

    Laoye, B J; Okurumeh, O A; Obagaye, O V; Olagunju, M O; Bankole, O O; Olubiyi, O O; Ogundele, O M

    2016-06-01

    The role of dopaminergic D2 receptor (D2R) autoregulation in dopamine (DA) neurotransmission cannot be overemphasized in cause and progression of disorders associated with complex behaviors. Although previous studies have shown that D2R is structurally and physiologically linked with calcium/calmodulin-dependent kinase II (CaMKIIα), however, the role of calmodulin in the CaMKIIα complex in D2R regulation remains elusive. In this study, using structural biology modeling softwares (iGEMDOCK and CueMol), we have shown the interaction between D2R, CaMKIIα, calmodulin, and DA under varying conditions. The outcomes of this study suggest that CaMKIIα causes a change in DA binding affinity to the D2R receptive site while the detached DA binds to calmodulin to stop the activity of D2R in the D2R-dopaminergic D1 receptor (D1R) heteromer. Ultimately, we concluded that D2R autoregulates to stop its heteromeric combination with D1R. D2R interacts with D1R to facilitate calcium movement that activates calmodulin, then CaMKIIα. The CaMKIIα-calmodulin complex changes the affinity of DA-D2R causing DA to break free and bind with calmodulin. PMID:26446938

  9. Cerebral misery perfusion diagnosed using hypercapnic blood-oxygenation-level-dependent contrast functional magnetic resonance imaging: a case report

    Directory of Open Access Journals (Sweden)

    D'Souza Olympio

    2010-02-01

    Full Text Available Abstract Introduction Cerebral misery perfusion represents a failure of cerebral autoregulation. It is an important differential diagnosis in post-stroke patients presenting with collapses in the presence of haemodynamically significant cerebrovascular stenosis. This is particularly the case when cortical or internal watershed infarcts are present. When this condition occurs, further investigation should be done immediately. Case presentation A 50-year-old Caucasian man presented with a stroke secondary to complete occlusion of his left internal carotid artery. He went on to suffer recurrent seizures. Neuroimaging demonstrated numerous new watershed-territory cerebral infarcts. No source of arterial thromboembolism was demonstrable. Hypercapnic blood-oxygenation-level-dependent-contrast functional magnetic resonance imaging was used to measure his cerebrovascular reserve capacity. The findings were suggestive of cerebral misery perfusion. Conclusions Blood-oxygenation-level-dependent-contrast functional magnetic resonance imaging allows the inference of cerebral misery perfusion. This procedure is cheaper and more readily available than positron emission tomography imaging, which is the current gold standard diagnostic test. The most evaluated treatment for cerebral misery perfusion is extracranial-intracranial bypass. Although previous trials of this have been unfavourable, the results of new studies involving extracranial-intracranial bypass in high-risk patients identified during cerebral perfusion imaging are awaited. Cerebral misery perfusion is an important and under-recognized condition in which emerging imaging and treatment modalities present the possibility of practical and evidence-based management in the near future. Physicians should thus be aware of this disorder and of recent developments in diagnostic tests that allow its detection.

  10. Measurements of diagnostic examination performance and correlation analysis using microvascular leakage, cerebral blood volume, and blood flow derived from 3T dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging in glial tumor grading

    International Nuclear Information System (INIS)

    To assess the diagnostic accuracy of microvascular leakage (MVL), cerebral blood volume (CBV) and blood flow (CBF) values derived from dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging (DSC-MR imaging) for grading of cerebral glial tumors, and to estimate the correlation between vascular permeability/perfusion parameters and tumor grades. A prospective study of 79 patients with cerebral glial tumors underwent DSC-MR imaging. Normalized relative CBV (rCBV) and relative CBF (rCBF) from tumoral (rCBVt and rCBFt), peri-enhancing region (rCBVe and rCBFe), and the value in the tumor divided by the value in the peri-enhancing region (rCBVt/e and rCBFt/e), as well as MVL, expressed as the leakage coefficient K2 were calculated. Hemodynamic variables and tumor grades were analyzed statistically and with Pearson correlations. Receiver operating characteristic (ROC) curve analyses were also performed for each of the variables. The differences in rCBVt and the maximum MVL (MVLmax) values were statistically significant among all tumor grades. Correlation analysis using Pearson was as follows: rCBVt and tumor grade, r = 0.774; rCBFt and tumor grade, r = 0.417; MVLmax and tumor grade, r = 0.559; MVLmax and rCBVt, r = 0.440; MVLmax and rCBFt, r = 0.192; and rCBVt and rCBFt, r = 0.605. According to ROC analyses for distinguishing tumor grade, rCBVt showed the largest areas under ROC curve (AUC), except for grade III from IV. Both rCBVt and MVLmax showed good discriminative power in distinguishing all tumor grades. rCBVt correlated strongly with tumor grade; the correlation between MVLmax and tumor grade was moderate. (orig.)

  11. Renal Heme Oxygenase-1 Induction with Hemin Augments Renal Hemodynamics, Renal Autoregulation, and Excretory Function

    Directory of Open Access Journals (Sweden)

    Fady T. Botros

    2012-01-01

    Full Text Available Heme oxygenases (HO-1; HO-2 catalyze conversion of heme to free iron, carbon monoxide, and biliverdin/bilirubin. To determine the effects of renal HO-1 induction on blood pressure and renal function, normal control rats (n=7 and hemin-treated rats (n=6 were studied. Renal clearance studies were performed on anesthetized rats to assess renal function; renal blood flow (RBF was measured using a transonic flow probe placed around the left renal artery. Hemin treatment significantly induced renal HO-1. Mean arterial pressure and heart rate were not different (115±5 mmHg versus 112±4 mmHg and 331±16 versus 346±10 bpm. However, RBF was significantly higher (9.1±0.8 versus 7.0±0.5 mL/min/g, P<0.05, and renal vascular resistance was significantly lower (13.0±0.9 versus 16.6±1.4 [mmHg/(mL/min/g], P<0.05. Likewise, glomerular filtration rate was significantly elevated (1.4±0.2 versus 1.0±0.1 mL/min/g, P<0.05, and urine flow and sodium excretion were also higher (18.9±3.9 versus 8.2±1.0 μL/min/g, P<0.05 and 1.9±0.6 versus 0.2±0.1 μmol/min/g, P<0.05, resp.. The plateau of the autoregulation relationship was elevated, and renal vascular responses to acute angiotensin II infusion were attenuated in hemin-treated rats reflecting the vasodilatory effect of HO-1 induction. We conclude that renal HO-1 induction augments renal function which may contribute to the antihypertensive effects of HO-1 induction observed in hypertension models.

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

    International Nuclear Information System (INIS)

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

  13. Dynamics of the basic indexes of vital functions of children with a cerebral paralysis under the action of methods of physical rehabilitation.

    Directory of Open Access Journals (Sweden)

    Kazakova S.M.

    2011-03-01

    Full Text Available It is shown that the complex program of physical rehabilitation improves the process of forming motor abilities and sensory systems for children, suffering a cerebral paralysis. The experiment involved 38 clients between the ages of early childhood (Center of social rehabilitation of disabled children of Melitopol. Proved that the use complex individual physical rehabilitation programs have increased the motor activity of children by 20-25%, visual acuity in 45-50% hearing loss - 20-25%, tactile sensitivity - 10-15%. The recommendations for parents of children in this nosology.

  14. Cerebral Palsy (CP) Quiz

    Science.gov (United States)

    ... Submit Button Past Emails CDC Features Pop Quiz: Cerebral Palsy Language: English Español (Spanish) Recommend on Facebook Tweet ... Sandy is the parent of a child with cerebral palsy and the Board President of Gio’s Garden , a ...

  15. Reversible cerebral vasoconstriction syndrome

    Directory of Open Access Journals (Sweden)

    Saini Monica

    2009-01-01

    Full Text Available Reversible cerebral vasoconstriction syndromes (RCVS are a group of disorders that have in common an acute presentation with headache, reversible vasoconstriction of cerebral arteries, with or without neurological signs and symptoms. In contrast to primary central nervous system vasculitis, they have a relatively benign course. We describe here a patient who was diagnosed with RCVS.

  16. Non-ionizing radiofrequency electromagnetic waves traversing the head can be used to detect cerebrovascular autoregulation responses

    Science.gov (United States)

    Oziel, M.; Hjouj, M.; Gonzalez, C. A.; Lavee, J.; Rubinsky, B.

    2016-02-01

    Monitoring changes in non-ionizing radiofrequency electromagnetic waves as they traverse the brain can detect the effects of stimuli employed in cerebrovascular autoregulation (CVA) tests on the brain, without contact and in real time. CVA is a physiological phenomenon of importance to health, used for diagnosis of a number of diseases of the brain with a vascular component. The technology described here is being developed for use in diagnosis of injuries and diseases of the brain in rural and economically underdeveloped parts of the world. A group of nine subjects participated in this pilot clinical evaluation of the technology. Substantial research remains to be done on correlating the measurements with physiology and anatomy.

  17. Changes in cerebral blood flow and psychometric indicators in veterans with early forms of chronic brain ischemia

    Directory of Open Access Journals (Sweden)

    Vasilenko Т.М.

    2015-09-01

    Full Text Available The goal is to study the cerebral blood flow and psychometric characteristics in veterans of Afghanistan with early forms of chronic brain ischemia. Material and Methods. The study included 74 veterans of the Afghan war aged from 45 to 55 years: group 1, 28 people with NPNKM; Group 2-28 patients with circulatory encephalopathy stage 1; group 3-18 healthy persons. Doppler examination of cerebral vessels was carried out on the unit «Smart-lite». Reactive and personal anxiety of patients was assessed using the scale of Spielberger, evaluation of the quality of life through the test SAN. Determining the level of neuroticism and psychoticism was conducted by the scale of neuroticism and psy-choticism. Results: The study of cerebral blood flow in the Afghan war veterans showed signs of insolvency of carotid and carotid-basilar anastomoses, hypoperfusion phenomenon with the depletion of autoregulation, violation of the outflow of venous blood at the level of the microvasculature, accompanied by cerebral arteries spasm. More than 40% of patients with early forms of chronic brain ischemia had high personal anxiety, low levels of well-being and activity, with maximum expression of dyscirculatory hypoxia. Conclusion. Readaptation of veterans of Afghanistan is accompanied by the changes in psychometric performance and the formation of the earliest forms of brain chronic ischemia associated with inadequate hemodynamics providing increased functional activity of the brain and the inefficiency of compensatory-adaptive reactions.

  18. The Effects of Acupuncture on Cerebral and Muscular Microcirculation: A Systematic Review of Near-Infrared Spectroscopy Studies

    Directory of Open Access Journals (Sweden)

    Ming-Yu Lo

    2015-01-01

    Full Text Available Acupuncture produces physiological effects via stimulating acupoints, proximal or distal to the region of effect. Near-infrared spectroscopy (NIRS noninvasively measures tissue-level hemodynamics in real time. We review the literature investigating the effect of acupuncture on muscular and/or cerebral microcirculation. As the basis, we queried PubMed in June 2014 for articles mentioning both acupuncture and NIRS in title/abstract. The reviewed papers investigated either cerebral (n = 11 or muscular hemodynamics (n = 5 and, based on STRICTA for reporting acupuncture methodology, were overall poor in quality. Acupuncture was found to influence regional oxygen saturation in cerebral and muscular tissue. The cortical response in healthy subjects varied across studies. For subjects with stroke or cerebrovascular dementia, findings suggest that acupuncture may modulate dysfunction in cerebral autoregulation. The muscular response to pressure techniques was more intense than that to needling or laser. Probe proximity could impact measurement sensitivity. No one study simultaneously investigated the direct and remote responses. Research utilizing NIRS to investigate the hemodynamics of acupuncture presently lacks in scope and quality. Improved designs, for example, placebo-controlled, randomized trials, and standardized intervention reporting will raise study quality. Exploiting NIRS in clinical settings, such as stroke, migraine, or other pain conditions, is worthwhile.

  19. Prolonged androgen deprivation may influence the autoregulation of estrogen receptors in the brain and pelvic floor muscles of male rats.

    Science.gov (United States)

    Wibowo, Erik; Calich, Hannah J; Currie, R William; Wassersug, Richard J

    2015-06-01

    Androgen deprivation in males has detrimental effects on various tissues and bodily functions, some of which can be restored by estradiol (E2) administration. We investigated how the duration of androgen deprivation affects the autoregulation of estrogen receptors (ERs) levels in core brain areas associated with sexual behavior and cognition, as well as in pelvic floor muscles (PFM). We also measured c-Fos levels in brain areas associated with sexual behavior shortly after the rats mated. Prolonged castration increases ERα levels in the preoptic area (POA) and E2 treatment reverses these effects. In the POA, c-Fos levels after mating are not affected by the duration of androgen deprivation and/or E2 treatment. ERβ levels in the POA as well as c-Fos levels in the POA and the core area of nucleus accumbens correlate with the mounting frequency for E2-treated Short-Term castrates. Additionally, ERβ levels in the medial amygdala are positively correlated with the mounting frequency of Long-Term castrates that received E2 treatment. In the hippocampus, ERs are downregulated only when E2 is administered early after castration, whereas downregulation of ERα in the prefrontal cortex only occurs with delayed E2 treatment. Early, but not delayed, E2 treatment after castration increases ERβ levels in the bulbocavernosus and ERα levels in the levator ani of male rats. Our data suggest that the duration of androgen deprivation may influence the autoregulation of ERs by E2 treatment in select brain areas and pelvic floor muscles of male rats. PMID:25746452

  20. Mapping of cerebral metabolic rate of oxygen using dynamic susceptibility contrast and blood oxygen level dependent MR imaging in acute ischemic stroke

    International Nuclear Information System (INIS)

    MR-derived cerebral metabolic rate of oxygen utilization (CMRO2) has been suggested to be analogous to PET-derived CMRO2 and therefore may be used for detection of viable tissue at risk for infarction. The purpose of this study was to evaluate MR-derived CMRO2 mapping in acute ischemic stroke in relation to established diffusion- and perfusion-weighted imaging. In 23 patients (mean age 63 ± 18.7 years, 11 women) with imaging findings for acute ischemic stroke, relative oxygen extraction fraction was calculated from quantitative transverse relaxation times (T2, T2*) and relative cerebral blood volume using a quantitative blood oxygenation level dependent (BOLD) approach in order to detect a local increase of deoxyhemoglobin. Relative CMRO2 (rCMRO2) maps were calculated by multiplying relative oxygen extraction fraction (rOEF) by cerebral blood flow, derived from PWI. After co-registration, rCMRO2 maps were evaluated in comparison with apparent diffusion coefficient (ADC) and time-to-peak (TTP) maps. Mean rCMRO2 values in areas with diffusion-restriction or TTP/ADC mismatch were compared with rCMRO2 values in the contralateral tissue. In tissue with diffusion restriction, mean rCMRO2 values were significantly decreased compared to perfusion-impaired (17.9 [95 % confidence interval 10.3, 25.0] vs. 58.1 [95 % confidence interval 50.1, 70.3]; P < 0.001) and tissue in the contralateral hemisphere (68.2 [95 % confidence interval 61.4, 75.0]; P < 0.001). rCMRO2 in perfusion-impaired tissue showed no significant change compared to tissue in the contralateral hemisphere (58.1 [95 % confidence interval 50.1, 70.3] vs. 66.7 [95 % confidence interval 53.4, 73.4]; P = 0.34). MR-derived CMRO2 was decreased within diffusion-restricted tissue and stable within perfusion-impaired tissue, suggesting that this technique may be adequate to reveal different pathophysiological stages in acute stroke. (orig.)

  1. Dynamic pattern of gene expression of ZnT-4, caspase-3, LC3, and PRG-3 in rat cerebral cortex following flurothyl-induced recurrent neonatal seizures.

    Science.gov (United States)

    Ni, Hong; Feng, Xing; Xiao, Zhuo-jun; Tao, Lu-yang; Jin, Mei-fang

    2011-12-01

    Zinc transporters, plasticity-related genes, and autophagic/apoptotic pathway both are associated with developmental seizure-induced brain excitotoxicity. Here, for the first time, we report the timing of expression pattern of zinc transporter 4 (ZnT-4), plasticity-related gene 3 (PRG-3), specific marker of autophagic vacuoles (LC3), and apoptotic marker caspase-3 in cerebral cortex following neonatal seizures. A seizure was induced by inhalant flurothyl daily in neonatal Sprague-Dawley rats from postnatal day 6 (P6). Rats were assigned into the recurrent-seizure group (RS, seizures induced in six consecutive days) and the control group. At 1.5 h, 3 h, 6 h, 12 h, 24 h, 48 h, 7 days, and 14 days after the last seizure, the mRNA level of the four genes in cerebral cortex was detected using RT-PCR method. At an early period 6 h or 12 h after the last seizures, both ZnT-4 and LC3 showed significantly up-regulated mRNA level while PRG-3 showed significantly down-regulated mRNA level at 12 h in cerebral cortex of RS group than those at the corresponding time point in control group. In the long-term time point of 7 days after the last seizure, the mRNA level of caspase-3 down-regulated; meanwhile, there was up-regulated mRNA level of LC-3 in RS group when compared to the control rats. This is the first report investigating the gene expression pattern of ZnT-4, PRG-3, LC-3, and caspase-3 in the developing brain. The results suggest that the disturbed expression pattern of the four genes might play a role in the pathophysiology of recurrent neonatal seizure-induced acute and long-term brain damage. PMID:21286846

  2. Mapping of cerebral metabolic rate of oxygen using dynamic susceptibility contrast and blood oxygen level dependent MR imaging in acute ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Gersing, Alexandra S.; Schwaiger, Benedikt J. [Technical University Munich, Klinikum rechts der Isar, Department of Neuroradiology, Munich (Germany); University of California, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Ankenbrank, Monika; Toth, Vivien; Bauer, Jan S.; Zimmer, Claus [Technical University Munich, Klinikum rechts der Isar, Department of Neuroradiology, Munich (Germany); Janssen, Insa [Technical University Munich, Department of Neurosurgery, Munich (Germany); Kooijman, Hendrik [Philips Healthcare, Hamburg (Germany); Wunderlich, Silke [Technical University Munich, Department of Neurology, Munich (Germany); Preibisch, Christine [Technical University Munich, Klinikum rechts der Isar, Department of Neuroradiology, Munich (Germany); Technical University Munich, Department of Neurology, Munich (Germany)

    2015-12-15

    MR-derived cerebral metabolic rate of oxygen utilization (CMRO{sub 2}) has been suggested to be analogous to PET-derived CMRO{sub 2} and therefore may be used for detection of viable tissue at risk for infarction. The purpose of this study was to evaluate MR-derived CMRO{sub 2} mapping in acute ischemic stroke in relation to established diffusion- and perfusion-weighted imaging. In 23 patients (mean age 63 ± 18.7 years, 11 women) with imaging findings for acute ischemic stroke, relative oxygen extraction fraction was calculated from quantitative transverse relaxation times (T2, T2*) and relative cerebral blood volume using a quantitative blood oxygenation level dependent (BOLD) approach in order to detect a local increase of deoxyhemoglobin. Relative CMRO{sub 2} (rCMRO{sub 2}) maps were calculated by multiplying relative oxygen extraction fraction (rOEF) by cerebral blood flow, derived from PWI. After co-registration, rCMRO{sub 2} maps were evaluated in comparison with apparent diffusion coefficient (ADC) and time-to-peak (TTP) maps. Mean rCMRO{sub 2} values in areas with diffusion-restriction or TTP/ADC mismatch were compared with rCMRO{sub 2} values in the contralateral tissue. In tissue with diffusion restriction, mean rCMRO{sub 2} values were significantly decreased compared to perfusion-impaired (17.9 [95 % confidence interval 10.3, 25.0] vs. 58.1 [95 % confidence interval 50.1, 70.3]; P < 0.001) and tissue in the contralateral hemisphere (68.2 [95 % confidence interval 61.4, 75.0]; P < 0.001). rCMRO{sub 2} in perfusion-impaired tissue showed no significant change compared to tissue in the contralateral hemisphere (58.1 [95 % confidence interval 50.1, 70.3] vs. 66.7 [95 % confidence interval 53.4, 73.4]; P = 0.34). MR-derived CMRO{sub 2} was decreased within diffusion-restricted tissue and stable within perfusion-impaired tissue, suggesting that this technique may be adequate to reveal different pathophysiological stages in acute stroke. (orig.)

  3. Cerebral haematocrit measurement

    International Nuclear Information System (INIS)

    Regional cerebral haematocrit was measured in a group of sixteen subjects by the single-photon emission computerized tomography method. This group included three normal subjects as controls and thirteen patients affected with ischaemic cerebral disease presenting clinically with transient ischaemic attacks-six patients - or recent cerebral stroke - seven patients. Two intravenous radioactive tracers - technetium-99m labelled autologous red blood cells and Tc-99m human serum albumin were used. Cerebral tomographic imaging was performed using a rotating scintillation camera. The values of cerebral haematocrit obtained, taken as a ratio to venous haematocrit, range between 0.65-0.88 in the subjects studied. As a general finding in normal subjects and in patients with transient ischaemic attacks, no significant difference between right and left hemispheric haematocrit value was noted. However, in the group of patients affected with stroke, a significant difference in the right versus left hemispheric Hct was observed in 3 patients, the higher Hct value corresponding to the affected side. The clinical implication is on the emphasis of cerebral Hct measurement when the measurement of cerebral blood flow or volume is sought. Also the variation in regional Hct value observed in patients with stroke, above mentioned, points to a regulation mechanism of the blood composition for optimal oxygen delivery to the brain that is impaired in these patients. 14 refs. (Author)

  4. Unilateral cerebral polymicrogyria with ipsilateral cerebral hemiatrophy

    International Nuclear Information System (INIS)

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

  5. Unilateral cerebral polymicrogyria with ipsilateral cerebral hemiatrophy

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-10-01

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

  6. An Eye for Possibilities in the Development of Children with Cerebral Palsy: Neurobiology and Neuropsychology in a Cultural-Historical Dynamic Understanding

    Directory of Open Access Journals (Sweden)

    Louise Bøttcher

    2010-06-01

    Full Text Available Taking children with Cerebral Palsy (CP as an example, the article seeks an understanding ofchildren with disabilities that connects neuropsychological theories of neural development withthe situated cognition perspective and the child as an active participant in its social practices. Theearly brain lesion of CP is reconceptualised as a neurobiological constraint that exists in therelations between the neural, cognitive and social levels. Through a multi-method study of twochildren with CP, it is analysed how neurobiological constraints arise, evolve and sometimes areresolved through local matches between the child and its social practices. The result is discussedas support of a developmental science approach that includes processes at the social practice levelalong with knowledge of biological processes.

  7. Regional kinetic constants and cerebral metabolic rate for glucose in normal human volunteers determined by dynamic positron emission tomography of [18F]-2-fluoro-2-deoxy-D-glucose

    International Nuclear Information System (INIS)

    Using dynamic [18F]fluorodeoxyglucose (FDG) positron emission tomography with a high-resolution, seven-slice positron camera, the kinetic constants of the original three-compartment model of Sokoloff and co-workers (1977) were determined in 43 distinct topographic brain regions of seven healthy male volunteers aged 28-38 years. Regional averages of the cerebral metabolic rate for glucose (CMRglu) were calculated both from individually fitted rate constants (CMRglukinetic) and from activity maps recorded 30-40 min after FDG injection, employing a four-parameter operational equation with standard rate constants from the literature (CMRgluautoradiographic). Metabolic rates and kinetic constants varied significantly among regions and subjects, but not between hemispheres. k1 ranged between 0.0485 +/- 0.00778 min-1 in the oval center and 0.0990 +/- 0.01347 min-1 in the primary visual cortex. k2 ranged from 0.1198 +/- 0.01533 min-1 in the temporal white matter to 0.1472 +/- 0.01817 min-1 in the cerebellar dentate nucleus. k3 was lowest (0.0386 +/- 0.01482 min-1) in temporal white matter and highest (0.0823 +/- 0.02552 min-1) in the caudate nucleus. Maximum likelihood cluster analysis revealed four homogeneous groups of brain regions according to their respective kinetic constants: (1) white matter and mixed brainstem structures; (2) cerebellar gray matter and hippocampal formations; (3) basal ganglia and frontolateral and primary visual cortex; and (4) other cerebral cortex and thalamus. Across the entire brain, k1 and k2 were positively correlated (r . 0.79); k1 and k3 showed some correlation (r . 0.59); but no significant linear association was found between k2 and k3. A strong correlation with CMRglu could be demonstrated for k1 (r . 0.88) and k3 (r . 0.90), but k2 was loosely correlated (r . 0.56)

  8. Neonatal Cerebral Sinovenous Thrombosis

    OpenAIRE

    J Gordon Millichap

    2006-01-01

    The presentation, treatment, and outcome of neonatal cerebral sinovenous thrombosis (SVT) were studied in 42 children, using neurology clinic records (1986-2005) at Indiana University School of Medicine.

  9. Cerebral Aneurysms Fact Sheet

    Science.gov (United States)

    ... cerebral aneurysm from forming. People with a diagnosed brain aneurysm should carefully control high blood pressure, stop smoking, and avoid cocaine use or other stimulant drugs. They should also ...

  10. Cerebral amyloid angiopathy

    Science.gov (United States)

    ... Fenichel GM, Jankovic J, Mazziotta JC, eds. Bradley's Neurology in Clinical Practice . 6th ed. Philadelphia, PA: Elsevier ... al. Course of cerebral amyloid angiopathy-related inflammation. Neurology. 2007;68:1411-1416. PMID: 17452586 www.ncbi. ...

  11. Cerebral aneurysms and inflammation

    Directory of Open Access Journals (Sweden)

    Toshihiro Yokoi

    2015-06-01

    Full Text Available Multiple inflammatory factors, playing a crucial role in cerebral aneurysm formation, have been identified. tumor necrosis factor-alpha (TNF-α has been revealed to have a close connection with several risk factors that affect aneurysm formation. Remarkable expression in aneurysm walls of mRNA for TNF-α has been observed in humans. Possible therapeutic interventions to reduce the formation of cerebral aneurysms may include the inhibition of mediators of inflammation.

  12. Rehabilitation in cerebral palsy.

    OpenAIRE

    Molnar, G. E.

    1991-01-01

    Cerebral palsy is the most frequent physical disability of childhood onset. Over the past four decades, prevalence has remained remarkably constant at 2 to 3 per 1,000 live births in industrialized countries. In this article I concentrate on the rehabilitation and outcome of patients with cerebral palsy. The epidemiologic, pathogenetic, and diagnostic aspects are highlighted briefly as they pertain to the planning and implementation of the rehabilitation process.

  13. Cerebral Palsy Litigation

    OpenAIRE

    Sartwelle, Thomas P.; Johnston, James C.

    2015-01-01

    The cardinal driver of cerebral palsy litigation is electronic fetal monitoring, which has continued unabated for 40 years. Electronic fetal monitoring, however, is based on 19th-century childbirth myths, a virtually nonexistent scientific foundation, and has a false positive rate exceeding 99%. It has not affected the incidence of cerebral palsy. Electronic fetal monitoring has, however, increased the cesarian section rate, with the expected increase in mortality and morbidity risks to mothe...

  14. Characterization of the Antirrhinum floral homeotic MADS-box gene deficiens: evidence for DNA binding and autoregulation of its persistent expression throughout flower development.

    Science.gov (United States)

    Schwarz-Sommer, Z; Hue, I; Huijser, P; Flor, P J; Hansen, R; Tetens, F; Lönnig, W E; Saedler, H; Sommer, H

    1992-01-01

    We have determined the structure of the floral homeotic deficiens (defA) gene whose mutants display sepaloid petals and carpelloid stamens, and have analysed its spatial and temporal expression pattern. In addition, several mutant alleles (morphoalleles) were studied. The results of these analyses define three functional domains of the DEF A protein and identify in the deficiens promoter a possible cis-acting binding site for a transcription factor which specifically upregulates expression of deficiens in petals and stamens. In vitro DNA binding studies show that DEF A binds to specific DNA motifs as a heterodimer, together with the protein product of the floral homeotic globosa gene, thus demonstrating that the protein encoded by deficiens is a DNA binding protein. Furthermore, Northern analysis of a temperature sensitive allele at permissive and non-permissive temperatures provides evidence for autoregulation of the persistent expression of deficiens throughout flower development. A possible mechanism of autoregulation is discussed. PMID:1346760

  15. BIOMECHANICAL PRINCIPLES PHYSICAL REHABILITATION OF CHILDREN WITH CEREBRAL PALSY

    OpenAIRE

    S. D. Korshunov; K. V. Davletyarova; L. V. Kapilevich

    2016-01-01

    Aim. We studied the basic biomechanical principles of physical rehabilitation of children with cerebral palsy.Materials and methods. Methods of Motion Tracking and electromyography investigated the biomechanical characteristics of gait in children with cerebral palsy. It is shown that the main differences between dynamic stereotype walk pediatric patients is to delay moving forward center of gravity and the disorganization of the lower limb movements (especially knee) in the vertical plane. P...

  16. Nanomedicine in cerebral palsy

    Directory of Open Access Journals (Sweden)

    Balakrishnan B

    2013-11-01

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

  17. Challenges in understanding the impact of blood pressure management on cerebral oxygenation in the preterm brain

    Directory of Open Access Journals (Sweden)

    Aminath eAzhan

    2012-12-01

    Full Text Available Systemic hypotension in preterm infants has been related to increased mortality, cerebrovascular lesions and neurodevelopmental morbidity. Treatment of hypotension with inotropic medications aims at preservation of end organ perfusion and oxygen delivery, especially the brain. The common inotropic medications in preterm infants include dopamine, dobutamine, adrenalin, with adjunctive use of corticosteroids in cases of refractory hypotension. Whether maintenance of mean arterial blood pressure (MAP by use of inotropic medication is neuroprotective or not remains unclear. This review explores the different inotropic agents and their effects on perfusion and oxygenation in the preterm brain, in clinical studies as well as in animal models. Dopamine and adrenalin, because of their -adrenergic vasoconstrictor actions, have raised concerns of reduction in cerebral blood flow (CBF. Several studies in hypotensive preterm infants have shown that dopamine elevates CBF together with increased MAP, in keeping with limited cerebro-autoregulation. Adrenaline is also effective in raising cerebral perfusion together with MAP in preterm infants. Experimental studies in immature animals show no cerebro-vasoconstrictive effects of dopamine or adrenaline, but demonstrate the consistent findings of increased cerebral perfusion and oxygenation with the use of dopamine, dobutamine and adrenaline, alongside with raised MAP. Both clinical and animal studies report the transitory effects of adrenaline in increasing plasma lactate, and blood glucose, which might render its use as a 2nd line therapy. To investigate the cerebral effects of inotropic agents in long-term outcome in hypotensive preterm infants, carefully designed prospective research possibly including preterm infants with permissive hypotension is required. Preterm animal models would be useful in investigating the relationship between the physiological effects of inotropes and histopathology outcomes in

  18. Improved detectability of microcirculatory dynamics by laser speckle flowmetry

    DEFF Research Database (Denmark)

    Postnov, Dmitry D; Sosnovtseva, Olga; Tuchin, Valery V

    2015-01-01

    Mechanisms of renal autoregulation generate oscillations in arterial blood flow at several characteristic frequencies. Full-field laser speckle flowmetry provides a real-time imaging of superficial blood microcirculation. The possibility to detect changes in oscillatory dynamics is an important...... issue in biomedical applications. In this paper we show how laser power density affects quality of the recorded signal and improves detectability of temporal changes in microvascular perfusion....

  19. Clinical study of cardiogenic cerebral embolism; A comparison of lesion size by CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Izumi, Masayuki; Mitsuma, Terunori (Aichi Medical Univ., Nagakute (Japan)); Ishikawa, Sawao; Takeda, Akio; Tanaka, Hisashi

    1993-06-01

    In order to investigate the distribution of lesion size and to determine the background factors responsible for large infarcts, we examined CT findings in 88 consecutive patients with acute cardiogenic cerebral embolism of the internal carotid arterial system. Lesion size was determined by brain CT, and expressed as the 'infarct index'. The typical CT finding was a sharply marginated lesion in the cortex corresponding to the occluded arterial territory, accompanied by mass effect. Over half of the cases showed an infarct index of 20% or less. Most cases had small lesions, with substantially fewer cases having large infarcts. The lack of large infarcts was attributable to early recanalization of the occluded artery. Several background factors were implicated in the large infarcts, including elevated hematocrit, fibrinogen, arterial blood pressure, cardiothoracic ratio (as seen in chest X-rays), and a shortening of activated partial thromboplastin time (APTT). Factors implicated in the formation of a large embolus included increased blood viscosity and coagulability (caused by dehydration), and a hypertension-induced shift of the lower limit of autoregulation to a higher level. Further study is needed to determine whether such changes arise as the cause or the effect of a cerebral embolism. (author).

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

    Directory of Open Access Journals (Sweden)

    Filippo Molinari

    2010-01-01

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

  1. Reduction in Cerebral Oxygenation After Prolonged Exercise in Hypoxia is Related to Changes in Blood Pressure.

    Science.gov (United States)

    Horiuchi, Masahiro; Dobashi, Shohei; Kiuchi, Masataka; Endo, Junko; Koyama, Katsuhiro; Subudhi, Andrew W

    2016-01-01

    We investigated the relation between blood pressure and cerebral oxygenation (COX) immediately after exercise in ten healthy males. Subjects completed an exercise and recovery protocol while breathing either 21% (normoxia) or 14.1% (hypoxia) O2 in a randomized order. Each exercise session included four sets of cycling (30 min/set, 15 min rest) at 50% of altitude-adjusted peak oxygen uptake, followed by 60 min of recovery. After exercise, mean arterial pressure (MAP; 87±1 vs. 84±1 mmHg, average values across the recovery period) and COX (68±1% vs. 58±1%) were lower in hypoxia compared to normoxia (Pblood pressure following exercise in hypoxia are (1) more pronounced than in normoxia, and (2) associated with reductions in COX. Together, these results suggest an impairment in cerebral autoregulation as COX followed changes in MAP more passively in hypoxia than in normoxia. These findings could help explain the increased risk for postexercise syncope at high altitude. PMID:26782200

  2. Cerebral palsy and multiple births.

    OpenAIRE

    Pharoah, P. O.; Cooke, T

    1996-01-01

    AIM: To compare the birthweight specific prevalence of cerebral palsy in singleton and multiple births. METHODS: Registered births of babies with cerebral palsy born to mothers resident in the counties of Merseyside and Cheshire during the period 1982 to 1989 were ascertained. RESULTS: The crude prevalence of cerebral palsy was 2.3 per 1000 infant survivors in singletons, 12.6 in twins, and 44.8 in triplets. The prevalence of cerebral palsy rose with decreasing birthweight. The birthweight sp...

  3. La parálisis cerebral como una condición dinámica del cerebro: un estudio secuencial del desarrollo de niños hasta los 6 años de edad / Cerebral Palsy as a Dynamic Condition of the Brain: A Sequential Study of the Development of Children up to 6 Years of Age

    OpenAIRE

    Enrique Moraleda Barreno; Modesto Jesús Romero López; María José Cayetano Menéndez

    2013-01-01

    La parálisis cerebral es un trastorno motor debido a inmadurez cerebral con numerosos déficits asociados, incluidos los adaptativos, sociales, motores, cognitivos y de la comunicación, y con gran impacto en el desarrollo. El objetivo del presente estudio fue estudiar el desarrollo durante un año de niños con parálisis cerebral de uno a seis años. El método empleado fue un diseño ex post facto evolutivo secuencial. Se utilizó la prueba de screening del Inventario de Desarrollo de Battelle en u...

  4. Experimental Focal Cerebral Ischemia

    DEFF Research Database (Denmark)

    Christensen, Thomas

    2007-01-01

    Focal cerebral ischemia due to occlusion of a major cerebral artery is the cause of ischemic stroke which is a major reason of mortality, morbidity and disability in the populations of the developed countries. In the seven studies summarized in the thesis focal ischemia in rats induced by occlusion...... of the middle cerebral artery (MCAO) was used as an experimental model of ischemic stroke. MCAO produces an acute lesion consisting of an ischemic core or focus with severely reduced blood flow surrounded by a borderzone or ischemic penumbra with less pronounced blood flow reduction. Cells in the...... radical scavenger α-PBN on the periinfarct depolarizations and infarct volume was investigated. In study number six, the activity of the mitochondrial electron transport complexes I, II and IV was evaluated histochemically during reperfusion after MCAO in order to assess the possible role of mitochondrial...

  5. Cerebral hemodynamics in migraine

    DEFF Research Database (Denmark)

    Hachinski, V C; Olesen, Jes; Norris, J W;

    1977-01-01

    Clinical and angiographic findings in migraine are briefly reviewed in relation to cerebral hemodynamic changes shown by regional cerebral blood flow (rCBF) studies. Three cases of migraine studied by the intracarotid xenon 133 method during attacks are reported. In classic migraine, with typical...... prodromal symptoms, a decrease in cerebral blood flow has been demonstrated during the aura. Occasionally, this flow decrease persists during the headache phase. In common migraine, where such prodromata are not seen, a flow decrease has not been demonstrated. During the headache phase of both types of...... migraine, rCBF has usually been found to be normal or in the high range of normal values. The high values may represent postischemic hyperemia, but are probably more frequently secondary to arousal caused by pain. Thus, during the headache phase rCBF may be subnormal, normal or high. These findings do not...

  6. Cerebral abscess in children

    International Nuclear Information System (INIS)

    A cerebral abscess (CA) is a focal, infectious process only or multiple, located in the cerebral parenchyma that produces tisular lysis and it behaves like a lesion of space occupative, being a suppurative illness, who origin is a distant infection, or for continuity that studies initially as an area of focal cerebritis and it is developed to a collection surrounded purulent. At the moment they are perfecting technical and protocols diagnoses and therapeutic and measures for allow to control the natural history of the illness, making from the confrontation to this pathology a necessarily interdisciplinary complicated art, stiller in the infantile population, due to their difficulty in the diagnosis and the relevance of the same one. The paper includes epidemiology, etiology, risk factors, localization, pathology, clinic, diagnoses, treatment and diagnostic images

  7. Cerebral fat embolism

    International Nuclear Information System (INIS)

    A case of cerebral fat embolism is reported. A 18-year-old patient with multiple bone fractures was in semiconma immediately after an injury. Brain CT showed no brain swelling or intracranial hematoma. Hypoxemia and alcoholemia were noted on admission, which returned to normal without improvement of consciousness level. In addition, respiratory symptoms with positive radiographic changes, tachycardia, pyrexia, sudden drop in hemoglobin level, and sudden thrombocytopenia developed. These symptoms were compatible with Gurd's criteria of systemic fat embolism. Eight days after injury, multiple low density areas appeared on CT and disappeared within the subsequent two weeks, and subdural effusion with cerebral atrophy developed. These CT findings were not considered due to cerebral trauma. Diagnosis of cerebral fat embolism was made. The subdural effusion was drained. Neurologic and pulmonary recoveries took place slowly and one month following the injury the patient became alert and exhibited fully coordinated limb movement. The CT scans of the present case well corresponded with hitherto reported pathological findings. Petechiae in the white matter must have developed on the day of injury, which could not be detected by CT examination. It is suggested that some petechial regions fused to purpuras and then gradually resolved when they were detected as multiple low density areas on CT. CT in the purpuras phase would have shown these lesions as high density areas. These lesions must have healed with formation of tiny scars and blood pigment which were demonstrated as the disappearance of multiple low density areas by CT examination. Cerebral atrophy and subsequent subdural effusion developed as a result of demyelination. The patient took the typical clinical course of cerebral fat embolism and serial CT scans served for its assessment. (author)

  8. Cerebral palsy and congenital malformations

    DEFF Research Database (Denmark)

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

    2007-01-01

    were reported to have a congenital malformation. The majority (8.6% of all children) were diagnosed with a cerebral malformation. The most frequent types of cerebral malformations were microcephaly and hydrocephaly. Non-cerebral malformations were present in 97 CP children and in further 14 CP children...

  9. Regulation of voltage-gated sodium channel expression in cancer: hormones, growth factors and auto-regulation.

    Science.gov (United States)

    Fraser, Scott P; Ozerlat-Gunduz, Iley; Brackenbury, William J; Fitzgerald, Elizabeth M; Campbell, Thomas M; Coombes, R Charles; Djamgoz, Mustafa B A

    2014-03-19

    Although ion channels are increasingly being discovered in cancer cells in vitro and in vivo, and shown to contribute to different aspects and stages of the cancer process, much less is known about the mechanisms controlling their expression. Here, we focus on voltage-gated Na(+) channels (VGSCs) which are upregulated in many types of carcinomas where their activity potentiates cell behaviours integral to the metastatic cascade. Regulation of VGSCs occurs at a hierarchy of levels from transcription to post-translation. Importantly, mainstream cancer mechanisms, especially hormones and growth factors, play a significant role in the regulation. On the whole, in major hormone-sensitive cancers, such as breast and prostate cancer, there is a negative association between genomic steroid hormone sensitivity and functional VGSC expression. Activity-dependent regulation by positive feedback has been demonstrated in strongly metastatic cells whereby the VGSC is self-sustaining, with its activity promoting further functional channel expression. Such auto-regulation is unlike normal cells in which activity-dependent regulation occurs mostly via negative feedback. Throughout, we highlight the possible clinical implications of functional VGSC expression and regulation in cancer. PMID:24493753

  10. The Rtr1p CTD phosphatase autoregulates its mRNA through a degradation pathway involving the REX exonucleases

    Science.gov (United States)

    Hodko, Domagoj; Ward, Taylor; Chanfreau, Guillaume

    2016-01-01

    Rtr1p is a phosphatase that impacts gene expression by modulating the phosphorylation status of the C-terminal domain of the large subunit of RNA polymerase II. Here, we show that Rtr1p is a component of a novel mRNA degradation pathway that promotes its autoregulation through turnover of its own mRNA. We show that the 3′UTR of the RTR1 mRNA contains a cis element that destabilizes this mRNA. RTR1 mRNA turnover is achieved through binding of Rtr1p to the RTR1 mRNP in a manner that is dependent on this cis element. Genetic evidence shows that Rtr1p-mediated decay of the RTR1 mRNA involves the 5′-3′ DExD/H-box RNA helicase Dhh1p and the 3′-5′ exonucleases Rex2p and Rex3p. Rtr1p and Rex3p are found associated with Dhh1p, suggesting a model for recruiting the REX exonucleases to the RTR1 mRNA for degradation. Rtr1p-mediated decay potentially impacts additional transcripts, including the unspliced BMH2 pre-mRNA. We propose that Rtr1p may imprint its RNA targets cotranscriptionally and determine their downstream degradation mechanism by directing these transcripts to a novel turnover pathway that involves Rtr1p, Dhh1p, and the REX family of exonucleases. PMID:26843527

  11. The cerebral venous system and hypoxia.

    Science.gov (United States)

    Wilson, Mark H; Imray, Christopher H E

    2016-01-15

    Most hypobaric hypoxia studies have focused on oxygen delivery and therefore cerebral blood inflow. Few have studied venous outflow. However, the volume of blood entering and leaving the skull (∼700 ml/min) is considerably greater than cerebrospinal fluid production (0.35 ml/min) or edema formation rates and slight imbalances of in- and outflow have considerable effects on intracranial pressure. This dynamic phenomenon is not necessarily appreciated in the currently taught static "Monro-Kellie" doctrine, which forms the basis of the "Tight-Fit" hypothesis thought to underlie high altitude headache, acute mountain sickness, and high altitude cerebral edema. Investigating both sides of the cerebral circulation was an integral part of the 2007 Xtreme Everest Expedition. The results of the relevant studies performed as part of and subsequent to this expedition are reviewed here. The evidence from recent studies suggests a relative venous outflow insufficiency is an early step in the pathogenesis of high altitude headache. Translation of knowledge gained from high altitude studies is important. Many patients in a critical care environment develop hypoxemia akin to that of high altitude exposure. An inability to drain the hypoxemic induced increase in cerebral blood flow could be an underappreciated regulatory mechanism of intracranial pressure. PMID:26294747

  12. Efficacy evaluation of cerebral perfusion pressure in complex treatment of eclamptic coma

    OpenAIRE

    Podolsky Yu.S.; Hapy I.H.

    2010-01-01

    The aim of this research is to study influence of cerebral perfusion pressure on the effectiveness of treatment of maternity patient in eclamptic coma. Fluctuation of average arterial pressure defines dynamics of the cerebral perfusion pressure. Active hypotensive therapy leads to reduction of cerebral blood flow, breaking perfusion balance of brain. The principal objective of treatment in eclamptic coma is to restore volemic indices by using stabizol, decrease of average arterial pressure (1...

  13. Cerebral atrophic and degenerative changes following various cerebral diseases, (1)

    International Nuclear Information System (INIS)

    Patients having cerebral atrophic and degenerative changes following hypoglycemia, cerebral contusion, or cerebral hypoxia including cerebrovascular disorders were reported. Description was made as to cerebral changes visualized on CT images and clinical courses of a patient who revived 10 minutes after heart stoppage during neurosurgery, a newborn with asphyxia, a patient with hypoglycemia, a patient who suffered from asphyxia by an accident 10 years before, a patient with carbon monoxide poisoning at an acute stage, a patient who had carbon monoxide poisoning 10 years before, a patient with diffuse cerebral ischemic changes, a patient with cerebral edema around metastatic tumor, a patient with respiration brain, a patient with neurological sequelae after cerebral contusion, a patient who had an operation to excise right parietal lobe artery malformation, and a patient who was shooted by a machine gun and had a lead in the brain for 34 years. (Tsunoda, M.)

  14. Comparative nonlinear modeling of renal autoregulation in rats: Volterra approach versus artificial neural networks

    DEFF Research Database (Denmark)

    Chon, K H; Holstein-Rathlou, N H; Marsh, D J;

    1998-01-01

    In this paper, feedforward neural networks with two types of activation functions (sigmoidal and polynomial) are utilized for modeling the nonlinear dynamic relation between renal blood pressure and flow data, and their performance is compared to Volterra models obtained by use of the leading ker...

  15. Evaluation of postural stability in children with hemiplegic cerebral palsy

    Science.gov (United States)

    Kenis-Coskun, Ozge; Giray, Esra; Eren, Beyhan; Ozkok, Ozlem; Karadag-Saygi, Evrim

    2016-01-01

    [Purpose] Postural stability is the ability of to maintain the position of the body within the support area. This function is affected in cerebral palsy. The aim of the present study was to compare static and dynamic postural stability between children with hemiplegic cerebral palsy and healthy controls. [Subjects and Methods] Thirty-seven children between the ages of 5 and 14 diagnosed with hemiplegic cerebral palsy (19 right, 18 left) and 23 healthy gender- and age-matched controls were included in the study. Postural stability was evaluated in both of the groups using a Neurocom Balance. Sway velocity was measured both with the eyes open and closed. Sit to stand and turning abilities were also assessed. [Results] The sway velocities with the eyes open and closed were significantly different between the groups. The weight transfer time in the Sit to Stand test was also significantly slower in children with cerebral palsy. Children with cerebral palsy also showed slower turning times and greater sway velocities during the Step and Quick Turn test on a force plate compared with their healthy counterparts. [Conclusion] Both static and dynamic postural stability parameters are affected in hemiplegic cerebral palsy. Further research is needed to define rehabilitation interventions to improve these parameters in patients. PMID:27313338

  16. 咀嚼对脑血流动力学影响的临床实验研究%Clinical experimental study on the effects of mastication on the dynamics of cerebral blood flow

    Institute of Scientific and Technical Information of China (English)

    魏洁; 陈树国; 徐璟; 郭长军; 袁硕

    2011-01-01

    目的 观察正常(铪)受试者咀嚼运动前后脑血流的改变,探讨咀嚼对脑血流动力学的影响及意义.方法 应用经颅彩色多谱勒超声扫描仪(transcranial color doppler,TCCD),探测30名正常(胎)受试者在安静状态下和咀嚼无糖口香糖10分钟后脑血流速的改变,对大脑中动脉收缩期峰流速(systolic peak flow velocity,Vs)、舒张期末峰流速(enddiastolic peak flow velocity,Vd)、平均峰流速(mean peak flow velocity,Vm)进行统计分析.结果 ①30名受试者咀嚼前脑血流速值均数(单位:cm/s):收缩期峰流速(Vs)-91.785,舒张期末峰流速(Vd)-39.385,平均峰流速(Vm)-55.735;咀嚼后均数:收缩期峰流速(Vs)-103.030,舒张期末峰流速(Vd)-46.015,平均峰流速(Vm)-64.090;②经两样本均数f检验可知咀嚼前后的大脑中动脉的收缩期峰流速(Vs)、舒张期末峰流速(Vd)、平均峰流速(Vm)的结果在男性与女性之间均无显著性差异(P>0.05);③受试者咀嚼前后配对t检验结果显示,受试者咀嚼后大脑中动脉收缩期峰流速(Vs)、舒张期末峰流速(Vd)及平均峰流速(Vm)与咀嚼前相比均有显著性差异(P<o.05).结论 咀嚼可使大脑中动脉血管充盈度增加,血流速度显著加快.%Objective To observe the cerebral blood flow changes of normal occlusion subjects before and after the movement of chewing, and to investigate the effects and significance of chewing on cerebral blood flow dynamics. Methods Transcranial Color Doppler (TCCD) was used to detect the changes of cerebral blood flow in 30 normal occlusion subjects in a quiet state and 10 minutes after chewing sugarless gum, and the systolic peak flow velocity (Vs), enddiastolic peak flow velocity (Vd), mean peak flow velocity (Vm) were all statistically analyzed. Results (Dthe mean value of cerebral blood flow of 30 subjects before chewing (unit: cm/s): systolic peak flow velocity (Vs) -91.785, enddiastolic peak flow velocity (Vd) -39.385, and

  17. Recurrent cerebral thrombosis

    International Nuclear Information System (INIS)

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

  18. Parálisis cerebral Cerebral palsy

    OpenAIRE

    Jorge Malagon Valdez

    2007-01-01

    El término parálisis cerebral (PC) engloba a un gran número de síndromes neurológicos clínicos, de etiología diversa. Estos síndromes se caracterizan por tener una sintomatología común: los trastornos motores. Algunos autores prefieren manejar términos como "encefalopatía fija", "encefalopatías no evolutivas". Se mencionan la utilidad de programas de intervención temprana y métodos especiales de rehabilitación, así como el manejo de las deficiencias asociadas como la epilepsia, deficiencia me...

  19. Parálisis cerebral Cerebral palsy

    Directory of Open Access Journals (Sweden)

    Jorge Malagon Valdez

    2007-01-01

    Full Text Available El término parálisis cerebral (PC engloba a un gran número de síndromes neurológicos clínicos, de etiología diversa. Estos síndromes se caracterizan por tener una sintomatología común: los trastornos motores. Algunos autores prefieren manejar términos como "encefalopatía fija", "encefalopatías no evolutivas". Se mencionan la utilidad de programas de intervención temprana y métodos especiales de rehabilitación, así como el manejo de las deficiencias asociadas como la epilepsia, deficiencia mental, trastornos del lenguaje, audición, visión, déficit de la atención que mejoran el pronóstico de manera significativa. El pronóstico también depende de la gravedad del padecimiento y de las manifestaciones asociadas.The term cerebral palsy (CP, is used for a great number of clinical neurological syndromes. The syndromes are characterized by having a common cause, motor defects. It is important, because they can cause a brain damage by presenting motor defects and some associated deficiencies, such as mental deficiency, epilepsy, language and visual defects and pseudobulbar paralysis, with the nonevolving fact. Some authors prefer using terms such as "non-evolving encephalopathies". In the treatment the utility of prevention programs of early stimulation and special rehabilitation methods, and treatment of associated deficiencies such as epilepsy, mental deficiency, language, audition and visual problems, and the attention deficit improve the prognosis in an important way. The prognosis depends on the severity of the disease and the associated manifestations.

  20. Modified GFAP promoter auto-regulates tet-activator expression for increased transactivation and reduced tTA-associated toxicity.

    Science.gov (United States)

    Barton, Michael D; Dunlop, J W; Psaltis, G; Kulik, J; DeGennaro, L; Kwak, Seung P

    2002-05-30

    Transactivator tTA is a necessary component of the tetracycline-regulated inducible gene system. While several transgenic animals have been described that express tTA in the central nervous system (CNS), their tTA levels are often limited, presumably due to toxic effects. We evaluated methods for auto-regulating tTA levels in astrocytes by modifying the transgenic promoter human GFAP (hGFAP). The hGFAP promoter carrying a single copy of the tet-operon in place of a native enhancer element (GFAPtetO1) drove expression of tTA at low levels during un-stimulated, basal condition. However the same promoter auto-induced expression of tTA to significant levels after tetracycline withdrawal. Glial cell-specificity of the promoter remained uncompromised during both basal and induced conditions. Transgenic rats were developed using the auto-inducible GFAPtetO1 promoter that expressed tTA mRNA to high levels in the brain. Expression was widespread within the CNS but enriched in astrocyte-rich regions including the cerebellum. Primary cerebellar astrocytes from GFAPtetO1 rats transfected with 07LacZ produced substantially greater inducibility of reporter gene compared to GFAP-tTA transgenic rats. Finally, GFAPtetO1 rats exhibited severe motor/gait deficit when bred to homozygosity. This phenotype was attributable to developmental abnormalities of the cerebellum and was completely abrogated by doxycycline administration. These results suggest that developmental toxicity resulting from tTA expression can be circumvented and tTA transgenics with high transactivation potential can be developed using the auto-activation strategy. Promoter modification presented here may be useful in developing highly inducible transgenic strategies without loss in tissue-specificity. PMID:12007834

  1. A γ-butyrolactone autoregulator-receptor system involved in the regulation of auricin production in Streptomyces aureofaciens CCM 3239.

    Science.gov (United States)

    Mingyar, Erik; Feckova, Lubomira; Novakova, Renata; Bekeova, Carmen; Kormanec, Jan

    2015-01-01

    The γ-butyrolactone (GBL) autoregulator-receptor systems play a role in controlling secondary metabolism and/or morphological differentiation in many Streptomyces species. We previously identified the aur1 gene cluster, located on the Streptomyces aureofaciens CCM 3239 large linear plasmid pSA3239, which is responsible for the production of the angucycline antibiotic auricin. Here, we describe the characterisation of two genes, sagA and sagR, encoding GBL autoregulatory signalling homologues, which lie in the upstream part of the aur1 cluster. SagA was similar to GBL synthases and SagR to GBL receptors. The expression of each gene is directed by its own promoter, sagAp for sagA and sagRp for sagR. Both genes were active mainly during the exponential phase, and their transcription was interdependent. The disruption of sagA abolished auricin production, while the disruption of sagR resulted in precocious but dramatically reduced auricin production. Transcription from the aur1Pp and aur1Rp promoters, which direct the expression of auricin-specific cluster-situated regulators (CSRs), was also precocious and increased in the sagR mutant strain. In addition, SagR was also shown to specifically bind both promoters in vitro. These results indicated that the SagA-SagR GBL system regulates auricin production. Unlike many other GBL receptors, SagR does not bind its own promoter, but Aur1R, an auricin-specific repressor from the family of pseudo GBL receptors, does bind both sagAp and sagRp promoters. Moreover, the expression of both promoters was deregulated in an aur1R mutant, indicating that the SagA-SagR GBL system is regulated by a feedback mechanism involving the auricin-specific CSR Aur1R, which regulates downstream. PMID:25219533

  2. Cerebral infarction showed hyperperfusion pattern on radionuclide cerebral angiography

    International Nuclear Information System (INIS)

    Four patients of middle cerebral infarctin showed hyperperfusion on radionuclide cerebral angiography and fan-shape accumulation at the area of middle cerebral artery on early and delayed brain scan. In these patients, bone scanning agents such as sup(99m)Tc-EHDP or sup(99m)Tc-MDP also prominently accumulated at the area of infarction. These findings were observed on the study when it was performed within seventeen days after attack, but reexamination tended to show normal or decreased perfusion on radionuclide cerebral angiography and improve abnormal accumulation on brain scans. The clinical diagnosis of these three patients were cerebral embolism with heart disease, but one patient was internal carotid artery occlusion. The prognosis of all patients were very good. The hyperperfusion on radionuclide cerebral angiography of these patients represents the luxury perfusion in the lesion and these infarction has been called hot stroke by Yarnell et al. (author)

  3. Comparative nonlinear modeling of renal autoregulation in rats: Volterra approach versus artificial neural networks.

    Science.gov (United States)

    Chon, K H; Holstein-Rathlou, N H; Marsh, D J; Marmarelis, V Z

    1998-01-01

    Volterra models have been increasingly popular in modeling studies of nonlinear physiological systems. In this paper, feedforward artificial neural networks with two types of activation functions (sigmoidal and polynomial) are utilized for modeling the nonlinear dynamic relation between renal blood pressure and flow data, and their performance is compared to Volterra models obtained by use of the leading kernel estimation method based on Laguerre expansions. The results for the two types of artificial neural networks (sigmoidal and polynomial) and the Volterra models are comparable in terms of normalized mean-square error (NMSE) of the respective output prediction for independent testing data. However, the Volterra models obtained via the Laguerre expansion technique achieve this prediction NMSE with approximately half the number of free parameters relative to either neural-network model. Nonetheless, both approaches are deemed effective in modeling nonlinear dynamic systems and their cooperative use is recommended in general, since they may exhibit different strengths and weaknesses depending on the specific characteristics of each application. PMID:18252466

  4. Phenylpropanolamine and cerebral hemorrhage

    International Nuclear Information System (INIS)

    Computerized tomography, carotid angiograms, and arteriography were used to diagnose several cases of cerebral hemorrhage following the use of phenylpropanolamine. The angiographic picture in one of the three cases was similar to that previously described in association with amphetamine abuse and pseudoephedrine overdose, both substances being chemically and pharmacologically similar to phenylpropanolamine. The study suggests that the arterial change responsible for symptoms may be due to spasm rather than arteriopathy. 14 references, 5 figures

  5. Nanomedicine in cerebral palsy

    OpenAIRE

    Balakrishnan B; Nance E; Johnston MV; Kannan R; Kannan S

    2013-01-01

    Bindu Balakrishnan,1 Elizabeth Nance,1 Michael V Johnston,2 Rangaramanujam Kannan,3 Sujatha Kannan1 1Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University; Baltimore, MD, USA; 2Department of Neurology and Pediatrics, Kennedy Krieger Institute, Baltimore, MD, USA; 3Department of Ophthalmology, Center for Nanomedicine, Johns Hopkins University, Baltimore, MD, USA Abstract: Cerebral palsy is a chronic childhood disorder that can have diverse etiologies. Injury to the...

  6. Cerebral palsy and aging

    OpenAIRE

    Haak, Peterson; Lenski, Madeleine; HIDECKER, MARY JO COOLEY; Li, Min; Paneth, Nigel

    2009-01-01

    Cerebral palsy (CP), the most common major disabling motor disorder of childhood, is frequently thought of as a condition that affects only children. Deaths in children with CP, never common, have in recent years become very rare, unless the child is very severely and multiply disabled. Thus, virtually all children assigned the diagnosis of CP will survive into adulthood. Attention to the adult with CP has been sparse, and the evolution of the motor disorder as the individual moves through ad...

  7. Osteopenia in cerebral palsy.

    OpenAIRE

    Shaw, N J; White, C. P.; Fraser, W. D.; ROSENBLOOM, L.

    1994-01-01

    The bone mineral density of the lumbar spine was assessed in nine non-ambulant children with cerebral palsy combined with measurements of serum 25-hydroxyvitamin D, parathyroid hormone, and urinary calcium excretion. Three children with recurrent fractures received treatment with bisphosphonates for periods ranging from 12-18 months. All the children demonstrated a severe reduction in bone mineral density even when allowance was made for their body weight. There were no consistent abnormaliti...

  8. Radiopharmaceuticals for cerebral studies

    International Nuclear Information System (INIS)

    For obtain good brain scintillation images in nuclear medicine must be used several radiopharmaceuticals. Cerebral studies give a tumors visual image as well as brain anomalities detection and are helpful in the diagnostic diseases . Are described in this work: a cerebrum radiopharmaceuticals classification,labelled compounds proceeding and Tc 99m good properties in for your fast caption, post administration and blood purification for renal way

  9. Plasticidad cerebral y lenguaje

    OpenAIRE

    Moreno-Torres Sánchez, Ignacio; Berthier Torres, Marcelo Luís

    2012-01-01

    Hace pocos años se daba por sentado que la recuperación del lenguaje tras una lesión cerebral era imposible, al igual que adquirir la lengua materna más allá de los tres primeros años de vida. Sin embargo, las últimas indagaciones muestran que nuestra capacidad de aprender es mucho mayor.

  10. Dysphagia in cerebral palsy

    OpenAIRE

    Salghetti, Annamaria; Martinuzzi, Andrea

    2013-01-01

    Abstract. Feeding problemsare often present in children with neuromotor impairment: dysphagia is usuallyseen in the most severe form of cerebral palsy and it’s defined as thedifficulty with any of the four phases of swallowing. Clinical consequences aremalnutrition and recurrent chest infections that reduce expected duration andquality of life. In order to prevent these consequences it’s important todetect with clinical and instrumental examinations dysphagia symptoms and totreat them. Clinic...

  11. Perfusion MRI in cerebral infarction

    International Nuclear Information System (INIS)

    Purpose: To investigate the hemodynamic changes in patients with acute cerebral stroke by perfusion MRI. Materials and methods: In 12 patients with acute stroke in the territory of the middle cerebral artery, perfusion MRI was performed. Peak time, mean transit time, regional cerebral blood volume and regional cerebral blood flow were calculated in the infarction, the peri-infarction area and the contralateral hemisphere. Results: In the infarction the mean blood flow was 29 ml/100 g/min, compared to about 40 ml/100 g/min in the peri-infarction area and the contralateral hemisphere. In two patients increased cortical blood flow was found in the infarction due to luxury perfusion. The cerebral blood volume was reduced in the infarction, but significantly increased, to 7.3 ml/100 g, in the peri-infarction tissue. Conclusion: Perfusion MRI allows one to differentiate various patterns of perfusion disorders in patients with acute cerebral stroke. (orig./AJ)

  12. Hyperventilation, cerebral perfusion, and syncope

    DEFF Research Database (Denmark)

    Immink, R V; Pott, F C; Secher, N H;

    2014-01-01

    dioxide (PaCO2) and oxygen (PaO2) partial pressures so that hypercapnia/hypoxia increases and hypocapnia/hyperoxia reduces global cerebral blood flow. Cerebral hypoperfusion and TLOC have been associated with hypocapnia related to HV. Notwithstanding pronounced cerebrovascular effects of PaCO2 the......This review summarizes evidence in humans for an association between hyperventilation (HV)-induced hypocapnia and a reduction in cerebral perfusion leading to syncope defined as transient loss of consciousness (TLOC). The cerebral vasculature is sensitive to changes in both the arterial carbon...... contribution of a low PaCO2 to the early postural reduction in middle cerebral artery blood velocity is transient. HV together with postural stress does not reduce cerebral perfusion to such an extent that TLOC develops. However when HV is combined with cardiovascular stressors like cold immersion or reduced...

  13. [Insomnia and cerebral hypoperfusion].

    Science.gov (United States)

    Káposzta, Zoltán; Rácz, Klára

    2007-11-18

    Insomnia is defined as difficulty with the initiation, maintenance, duration, or quality of sleep that results in the impairment of daytime functioning, despite adequate opportunity and circumstances for sleep. In most countries approximately every third inhabitant has insomnia. Insomnia can be classified as primary and secondary. The pathogenesis of primary insomnia is unknown, but available evidence suggests a state of hyperarousal. Insomnia secondary to other causes is more common than primary insomnia. Cerebral hypoperfusion can be the cause of insomnia in some cases. In such patients the cerebral blood flow should be improved using parenteral vascular therapy. If insomnia persists despite treatment, then therapy for primary insomnia should be instituted using benzodiazepine-receptor agonists such as Zolpidem, Zopiclone, or Zaleplon. In those cases Midazolam cannot be used for the treatment of insomnia due to its marked negative effect on cerebral blood flow. In Hungary there is a need to organize multidisciplinary Insomnia Clinics because insomnia is more than a disease, it is a public health problem in this century. PMID:17988972

  14. Cerebral malformations without antenatal diagnosis

    International Nuclear Information System (INIS)

    Cerebral malformations are usually described following the different steps in development. Disorders of neurulation (dysraphisms), or diverticulation (holoprosencephalies and posterior fossa cysts), and total commissural agenesis are usually diagnosed in utero. In contrast, disorders of histogenesis (proliferation-differentiation, migration, organization) are usually discovered in infants and children. The principal clinical symptoms that may be a clue to cerebral malformation include congenital hemiparesis, epilepsy and mental or psychomotor retardation. MRI is the imaging method of choice to assess cerebral malformations. (orig.)

  15. Cerebral malformations without antenatal diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Girard, Nadine J. [Diagnostic Neuroradiology, Hopital Timone, Marseille (France)

    2010-06-15

    Cerebral malformations are usually described following the different steps in development. Disorders of neurulation (dysraphisms), or diverticulation (holoprosencephalies and posterior fossa cysts), and total commissural agenesis are usually diagnosed in utero. In contrast, disorders of histogenesis (proliferation-differentiation, migration, organization) are usually discovered in infants and children. The principal clinical symptoms that may be a clue to cerebral malformation include congenital hemiparesis, epilepsy and mental or psychomotor retardation. MRI is the imaging method of choice to assess cerebral malformations. (orig.)

  16. Natriuretic peptides and cerebral hemodynamics

    DEFF Research Database (Denmark)

    Guo, Song; Barringer, Filippa; Zois, Nora Elisabeth;

    2014-01-01

    decompensated disease. In contrast, their biological effects on the cerebral hemodynamics are poorly understood. In this mini-review, we summarize the hemodynamic effects of the natriuretic peptides with a focus on the cerebral hemodynamics. In addition, we will discuss its potential implications in diseases...... where alteration of the cerebral hemodynamics plays a role such as migraine and acute brain injury including stroke. We conclude that a possible role of the peptides is feasible as evaluated from animal and in vitro studies, but more research is needed in humans to determine the precise response on...... cerebral vessels....

  17. 老年高血压患者动态血压特点及其与脑卒中关系%The Dynamic Blood Pressure Characteristics of Elderly Hypertensive Patients and Its Relationship with Cerebral Apoplexy

    Institute of Scientific and Technical Information of China (English)

    黄万慧

    2014-01-01

    To study the dynamic blood pressure characteristics of elderly hypertensive patients and its relationship with cerebral apoplexy.Method:267 hypertension patients were selected as the research object in our hospital from February 2013 to February 2014,they were divided into the elderly group(the group A,149 patients)and the non-elderly group(the group B,118 patients)according to patients’ age. On the basis of this group again,according to whether patients with combined stroke will be divided into the stroke group A1 and B1 and the non-stroke group A2 and B2. Ambulatory blood pressure of 267 cases were monitored,the blood pressure characteristics two groups was observed and its relationship with cerebral apoplexy was analyzed.Result:In the group A whether merger or stroke,its blood pressure circadian rhythm was lower than that in the group B(P<0.05);the pulse pressure pulse pressure had significant difference between the group A and the group B(P<0.05). Nighttime systolic blood pressure of the A1 group was obviously higher than that of the rest of the three groups(P<0.05).Conclusion:Low blood pressure circadian rhythm,pressing of arteries and veins increases blood pressure and systolic blood pressure at night increased dynamic is one of the reasons for the elderly patients with hypertension complicated by stroke,to analyze the change characteristics of senile hypertension and its and the relationship between cerebral apoplexy can effectively prevent the disease caused by cardiovascular disease, and through the individual treatment plan to ensure the clinical therapeutic effect.%目的:探讨老年高血压患者动态血压特点与脑卒中的关系。方法:选择2013年2月-2014年2月本院收治的267例高血压患者作为研究对象,根据患者的年龄将其分为老年组149例(A组)和非老年组118例(B组)。在此基础上再次进行分组,根据患者是否合并脑卒中将上述两组分为脑卒中组A1和B1

  18. La parálisis cerebral como una condición dinámica del cerebro: un estudio secuencial del desarrollo de niños hasta los 6 años de edad / Cerebral Palsy as a Dynamic Condition of the Brain: A Sequential Study of the Development of Children up to 6 Years of Age

    Directory of Open Access Journals (Sweden)

    Enrique Moraleda Barreno

    2013-03-01

    Full Text Available La parálisis cerebral es un trastorno motor debido a inmadurez cerebral con numerosos déficits asociados, incluidos los adaptativos, sociales, motores, cognitivos y de la comunicación, y con gran impacto en el desarrollo. El objetivo del presente estudio fue estudiar el desarrollo durante un año de niños con parálisis cerebral de uno a seis años. El método empleado fue un diseño ex post facto evolutivo secuencial. Se utilizó la prueba de screening del Inventario de Desarrollo de Battelle en un pretest y en un postest transcurrido un año. La muestra estuvo compuesta por 41 niños de entre 1 y 6 años de edad con diagnóstico de parálisis cerebral infantil. Los niños mostraban puntuaciones en el postest significativamente superiores en todas las áreas estudiadas. Se observó una mejora generalizada en las capacidades de la mayoría de los sujetos. Se discuten las posibles influencias que contribuyen a estas mejoras en los cocientes de desarrollo en la obtención de estos resultados.

  19. Comparison of Two Algorithms for Analysis of Perfusion Computed Tomography Data for Evaluation of Cerebral Microcirculation in Chronic Subdural Hematoma.

    Science.gov (United States)

    Trofimov, Alexey O; Kalentiev, George; Voennov, Oleg; Yuriev, Michail; Agarkova, Darya; Trofimova, Svetlana; Bragin, Denis E

    2016-01-01

    The aim of this work was comparison of two algorithms of perfusion computed tomography (PCT) data analysis for evaluation of cerebral microcirculation in the perifocal zone of chronic subdural hematoma (CSDH). Twenty patients with CSDH after polytrauma were included in the study. The same PCT data were assessed quantitatively in cortical brain region beneath the CSDH (zone 1), and in the corresponding contralateral brain hemisphere (zone 2) without and with the use of perfusion calculation mode excluding vascular pixel 'Remote Vessels' (RV); 1st and 2nd analysis method, respectively. Comparison with normal values for perfusion indices in the zone 1 in the 1st analysis method showed a significant (p < 0.01) increase in CBV and CBF, and no significant increase in MTT and TTP. Use of the RV mode (2nd analysis method) showed no statistically reliable change of perfusion parameters in the microcirculatory blood flow of the 2nd zone. Maintenance of microcirculatory blood flow perfusion reflects the preservation of cerebral blood flow autoregulation in patients with CSDH. PMID:27526170

  20. Cerebral oxygenation after birth

    DEFF Research Database (Denmark)

    Hessel, Trine W; Hyttel-Sorensen, Simon; Greisen, Gorm

    2014-01-01

    AIM: To compare absolute values of regional cerebral tissue oxygenation (cStO2 ) during haemodynamic transition after birth and repeatability during steady state for two commercial near-infrared spectroscopy (NIRS) devices. METHODS: In a prospective observational study, the INVOS 5100C and FORE...... INVOS and FORE-SIGHT cStO2 estimates showed oxygenation-level-dependent difference during birth transition. The better repeatability of FORE-SIGHT could be due to the lower response to change in saturation....

  1. Techniques in cerebral protection

    International Nuclear Information System (INIS)

    Carotid angioplasty and stenting is a valid alternative option to conventional carotid endarterectomy in the treatment of carotid artery stenosis. During the stenting process, however, distal embolization can occur with neurological consequences. To avoid this, cerebral protection devices have been introduced. Three principal types of protection system have been developed: distal balloon occlusion, distal filters and proximal protection with or without reversal of flow. As protection devices became the focus of interest by manufactures and physicians, several trials are going on worldwide to analyze the characteristics of each of them and to evaluate their efficacy to reduce the rate of distal embolization

  2. Cerebral blood flow tomography with xenon-133

    DEFF Research Database (Denmark)

    Lassen, N A

    1985-01-01

    Cerebral blood flow (CBF) can be measured tomographically by inhalation of Xenon-133. The calculation is based on taking a sequence of tomograms during the wash-in and wash-out phase of the tracer. Due to the dynamic nature of the process, a highly sensitive and fast moving single photon emission...... other tracers for CBF tomography using SPECT is summarized with emphasis on the 99mTc chelates that freely pass the intact blood-brain barrier. The highly sensitive brain-dedicated SPECT systems described are a prerequisite for achieving high resolution tomograms with such tracers....

  3. Therapeutic interventions in cerebral palsy.

    Science.gov (United States)

    Patel, Dilip R

    2005-11-01

    Various therapeutic interventions have been used in the management of children with cerebral palsy. Traditional physiotherapy and occupational therapy are widely used interventions and have been shown to be of benefit in the treatment of cerebral palsy. Evidence in support of the effectiveness of the neurodevelopmental treatment is equivocal at best. There is evidence to support the use and effectiveness of neuromuscular electrical stimulation in children with cerebral palsy. The effectiveness of many other interventions used in the treatment of cerebral palsy has not been clearly established based on well-controlled trials. These include: sensory integration, body-weight support treadmill training, conductive education, constraint-induced therapy, hyperbaric oxygen therapy, and the Vojta method. This article provides an overview of salient aspects of popular interventions used in the management of children with cerebral palsy. PMID:16391455

  4. Cerebral Hemorrhage and APOE genotype

    Institute of Scientific and Technical Information of China (English)

    Sun xiaojiang; Wu ping; Zhang jing; Lu shanqing; Li bing

    2000-01-01

    Background and Purpose: Current evidence Suggests that the apolipoprotein E (APOE)ε 4 allele predisposes to cerebral amyloid angiopathy (CAA) whereas ε 2 is associated with CAA-zelated hemorrhage. In this study we examined potential clinical risk factors inpatients with cerebral hemorrhage and assessed these with respect to APOE genotype. Methoeds: 146 patinas with cerebral hemorrhage and 70 normal controls were investigated. APOE genotypes were determined with use of polymerase Chain reaction techniques.Results: The frequency of allele gene ( 0.180 ) and the percentage of the APOE ε 4 genotype in the cerebral hemorrhage group were Significantly higher as compared with the e 4 prequency ( O.O72 ) in the control group respectively ( p=O.O389 ) .Conelusious: APOE ε 4 :allele is a risk gene for cerebral hemorrhage.

  5. Cerebral imaging in pediatrics

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, I. [London, Great Ormond Street Hospital for Children (United Kingdom)

    1998-06-01

    Radioisotope brain imaging has focused mainly on regional cerebral blood flow (rCBF). However the use of ligand which go to specific receptor sites is being introduced in pediatrics, mainly psychiatry. rCBF is potentially available in many institutions, especially with the availability of multi-headed gamma cameras. The use of this technique in pediatrics requires special attention to detail in the manner of data acquisition and handling the child. The interpretation of the rCBF study in a child requires knowledge of normal brain maturation. The major clinical use in pediatrics is epilepsy because of the advances in surgery and the frequency of complex partial seizures. Other indications in pediatric neurology include brain death, acute neurological loss including stroke, language disorders, cerebral palsy, hypertension due to renovascular disease, traumatic brain injury and migraine. There are pediatric physiological conditions in which rCBF has been undertaken, these include anorexia nervosa, autism, Gilles de la Tourette syndrome (GTS) and attention deficit disorder-hyperactivity (ADHD). Research using different ligands to specific receptor sites will also be reviewed in pediatrics.

  6. Cerebral imaging in pediatrics

    International Nuclear Information System (INIS)

    Radioisotope brain imaging has focused mainly on regional cerebral blood flow (rCBF). However the use of ligand which go to specific receptor sites is being introduced in pediatrics, mainly psychiatry. rCBF is potentially available in many institutions, especially with the availability of multi-headed gamma cameras. The use of this technique in pediatrics requires special attention to detail in the manner of data acquisition and handling the child. The interpretation of the rCBF study in a child requires knowledge of normal brain maturation. The major clinical use in pediatrics is epilepsy because of the advances in surgery and the frequency of complex partial seizures. Other indications in pediatric neurology include brain death, acute neurological loss including stroke, language disorders, cerebral palsy, hypertension due to renovascular disease, traumatic brain injury and migraine. There are pediatric physiological conditions in which rCBF has been undertaken, these include anorexia nervosa, autism, Gilles de la Tourette syndrome (GTS) and attention deficit disorder-hyperactivity (ADHD). Research using different ligands to specific receptor sites will also be reviewed in pediatrics

  7. Cerebral sinus venous thrombosis.

    Science.gov (United States)

    Alvis-Miranda, Hernando Raphael; Milena Castellar-Leones, Sandra; Alcala-Cerra, Gabriel; Rafael Moscote-Salazar, Luis

    2013-10-01

    Cerebral sinus venous thrombosis (CSVT) is a rare phenomenon that can be seen with some frequency in young patients. CSVT is a multifactorial condition with gender-related specific causes, with a wide clinical presentation, the leading causes differ between developed and developing countries, converting CSVT in a condition characterized by a highly variable clinical spectra, difficult diagnosis, variable etiologies and prognosis that requires fine medical skills and a high suspicious index. Patients who presents with CSVT should underwent to CT-scan venography (CVT) and to the proper inquiry of the generating cause. This disease can affect the cerebral venous drainage and related anatomical structure. The symptoms may appear in relation to increased intracranial pressure imitating a pseudotumorcerebri. Prognosis depends on the early detection. Correcting the cause, generally the complications can be prevented. Mortality trends have diminished, and with the new technologies, surely it will continue. This work aims to review current knowledge about CSVT including its pathogenesis, etiology, clinical manifestations, diagnosis, and treatment. PMID:24347950

  8. Cerebral sinus venous thrombosis

    Directory of Open Access Journals (Sweden)

    Hernando Raphael Alvis-Miranda

    2013-01-01

    Full Text Available Cerebral sinus venous thrombosis (CSVT is a rare phenomenon that can be seen with some frequency in young patients. CSVT is a multifactorial condition with gender-related specific causes, with a wide clinical presentation, the leading causes differ between developed and developing countries, converting CSVT in a condition characterized by a highly variable clinical spectra, difficult diagnosis, variable etiologies and prognosis that requires fine medical skills and a high suspicious index. Patients who presents with CSVT should underwent to CT-scan venography (CVT and to the proper inquiry of the generating cause. This disease can affect the cerebral venous drainage and related anatomical structure. The symptoms may appear in relation to increased intracranial pressure imitating a pseudotumorcerebri. Prognosis depends on the early detection. Correcting the cause, generally the complications can be prevented. Mortality trends have diminished, and with the new technologies, surely it will continue. This work aims to review current knowledge about CSVT including its pathogenesis, etiology, clinical manifestations, diagnosis, and treatment.

  9. Obstructive hydrocephalus resulting from cerebral venous thrombosis

    OpenAIRE

    2011-01-01

    Cerebral venous thrombosis is a rare form of stroke in childhood. Increased intracranial pressure is a well-defined complication of cerebral venous thrombosis but obstructive hydrocephalus as a presentation finding of cerebral venous thrombosis is rarely described. A child case of cerebral sinus thrombosis presenting with obstructive hydrocephalus and management of clinical condition is presented with discussion of reported cases and treatment recommendations.

  10. CEREBRAL PALSY AND MUSIC ACHIEVEMENT

    Directory of Open Access Journals (Sweden)

    Miodrag L. STOSHLJEVIKJ

    2008-12-01

    Full Text Available Pupils with cerebral palsy attend elementary education accordind to a regular and special teaching plan and program. Regular school curriculum was reformed in 1992, while special plan and program has not been changed and adapted according to pupil’s needs and capacities. Music is one of the best means of expressing oneself and plays a very important role in the development of every child, the child with cerebral palsy in particular.In order to test the possibility of pupils with cerebral palsy, with and without mental retardation, to apprehend the actual program content, we have conducted research on musical achievement of children with cerebral palsy. During 2007 a research was carried out, on the sample of 27 pupils with cerebral palsy and mild mental retardation who attended classes in the school “Miodrag Matikj”, and a sample of16 students with cerebral palsy without mental retardation who attended the school “Dr. Dragan Hercog” in Belgrade.Results of the research, as well as analysis of music curriculum content, indicated that the capacities of students with cerebral palsy to carry out the curriculum tasks require special approach and methodology. Therefore, we introduced some proposals to overcome the difficulties in fulfilling music curriculum demands of those pupils. We made special emphasis on the use of computer based Assistive technology which facilitates the whole process to a large extent.

  11. Biomechanical bases of rehabilitation of children with cerebral palsy

    Science.gov (United States)

    Davlet'yarova, K. V.; Korshunov, S. D.; Kapilevich, L. V.

    2015-11-01

    Biomechanical analysis and the study results of children's with cerebral palsy (CP) muscles bioelectrical activity while walking on a flat surface are represented. Increased flexion in the hip and shoulder joints and extension in the elbow joint in children with cerebral palsy were observed, with the movement of the lower limbs had less smooth character in comparison with the control group. Herewith, the oscillation amplitude was significantly increased, and the frequency in the m. gastrocnemius and m. lateralis was decreased. It was shown, that the dynamic stereotype of walking in children with cerebral palsy was characterized by excessive involvement of m. gastrocnemius and m.latissimus dorsi in locomotion. Thus, resulting biomechanical and bioelectrical parameters of walking should be considered in the rehabilitation programs development.

  12. Tomographic non-invasive measurements of regional cerebral blood flow

    International Nuclear Information System (INIS)

    The measurement of the regional cerebral bloodflow by means of the dynamic single-photon-emissioncomputed tomography is a method of examination which is completely free of risk for the patient, causes no inconvenience and can be repeated whenever it seems necessary. This method gives a quantitative explanation for the distribution of the effective cerebral perfusion and can only be substituted by the very complicated positron-emission-computed tomography. As well as the exact assessment of the hemodynamic relevance of cerebral vascular disease, this method enables us to prove whether or not in various types of psychiatric disorders an interference in the regional perfusion exists. This method can also contribute to the clarification of pathogenic mechanisms, as well as to the nosological classification of specific psychopathological conditions. (orig.)

  13. CEREBRAL PALSY : ANTENATAL RISK FACTORS

    Directory of Open Access Journals (Sweden)

    Srinivasa Rao

    2015-05-01

    Full Text Available INTRODUCTION: Cerebral palsy (CP is a group of permanent movement disorders that appear in early childhood. Cerebral palsy is caused by abnormal development or damage to the parts of the brain that control movement, balance, and posture. Most often the problems occur during pregnancy; however, they may also occur during childbirth, or shortly after birth. Often the cause is unknown. AIM: To study the different antenatal maternal risk factors associated with cerebral palsy in the study group. MATERIA LS AND METHODS: Retrospective study was done to assess possible associated antenatal risk factors for cerebral palsy. Mothers of 100 cerebral palsy children were selected who are treated in Rani Chandramani Devi Hospital, a Government hospital in Visakhapa tn am, Andhra Pradesh State, India , from 2012 to 2014 and 100 controls, mothers of normal children were studied. Detailed antenatal history was obtained from the mothers of the children in both affected and control group. RESULTS: From the data, we conclude that the association of maternal anaemia with cerebral palsy is 7.3 times higher; association of maternal hypertension with cerebral palsy is 6.6 time higher, association with Pre - eclampsia is 6 times higher; association with Eclampsia is 8.6 times higher ; with antepartum haemorrhage, the association is 8.6 times higher and association of multiple pregnancy with cerebral palsy is 4.8 times higher than with controls. CONCLUSION: From this study of the role of antenatal risk factors, in the occurrence of cer ebral palsy in children it is concluded that the most common risk factor associated with cerebral palsy is the maternal anaemia and the other important risk factors associated being hypertension, pre eclampsia, eclampsia, antepartum haemorrhage and multipl e births.

  14. CEREBRAL PALSY AND MUSIC ACHIEVEMENT

    OpenAIRE

    Miodrag L. STOSHLJEVIKJ; EMINOVIKJ Fadilj N.; NIKIKJ Radmila M.; Gordana I. ACHIKJ; Sanela R. PACIKJ

    2015-01-01

    Pupils with cerebral palsy attend elementary education accordind to a regular and special teaching plan and program. Regular school curriculum was reformed in 1992, while special plan and program has not been changed and adapted according to pupil’s needs and capacities. Music is one of the best means of expressing oneself and plays a very important role in the development of every child, the child with cerebral palsy in particular.In order to test the possibility of pupils with cerebral pal...

  15. Partial pharmacologic blockade shows sympathetic connection between blood pressure and cerebral blood flow velocity fluctuations.

    Science.gov (United States)

    Hilz, Max J; Wang, Ruihao; Marthol, Harald; Liu, Mao; Tillmann, Alexandra; Riss, Stephan; Hauck, Paulina; Hösl, Katharina M; Wasmeier, Gerald; Stemper, Brigitte; Köhrmann, Martin

    2016-06-15

    Cerebral autoregulation (CA) dampens transfer of blood pressure (BP)-fluctuations onto cerebral blood flow velocity (CBFV). Thus, CBFV-oscillations precede BP-oscillations. The phase angle (PA) between sympathetically mediated low-frequency (LF: 0.03-0.15Hz) BP- and CBFV-oscillations is a measure of CA quality. To evaluate whether PA depends on sympathetic modulation, we assessed PA-changes upon sympathetic stimulation with and without pharmacologic sympathetic blockade. In 10 healthy, young men, we monitored mean BP and CBFV before and during 120-second cold pressor stimulation (CPS) of one foot (0°C ice-water). We calculated mean values, standard deviations and sympathetic LF-powers of all signals, and PAs between LF-BP- and LF-CBFV-oscillations. We repeated measurements after ingestion of the adrenoceptor-blocker carvedilol (25mg). We compared parameters before and during CPS, without and after carvedilol (analysis of variance, post-hoc t-tests, significance: p<0.05). Without carvedilol, CPS increased BP, CBFV, BP-LF- and CBFV-LF-powers, and shortened PA. Carvedilol decreased resting BP, CBFV, BP-LF- and CBFV-LF-powers, while PAs remained unchanged. During CPS, BPs, CBFVs, BP-LF- and CBFV-LF-powers were lower, while PAs were longer with than without carvedilol. With carvedilol, CPS no longer shortened resting PA. Sympathetic activation shortens PA. Partial adrenoceptor blockade abolishes this PA-shortening. Thus, PA-measurements provide a subtle marker of sympathetic influences on CA and might refine CA evaluation. PMID:27206903

  16. Cerebral toxoplasmosis in AIDS

    International Nuclear Information System (INIS)

    Since 1982 (Hauser and co-workers), literature has reported focal cerebral tissue charges in AIDS patients whose diagnosis was unclear at first but which could be identified finally as florid toxoplasmosis encephalitis by biopsy and autopsy. It was found that the value of otherwise reliable serological tests (KBR, Sabin-Feldmann tests, etc.) is questionable in patients with severely impaired or incompetent immune systems, and, in particular, that a negative or uncharacteristic test result may not preclude any opportunistic infection process. Furthermore, isolation of Toxoplasma gondii or specific antibodies from the cerebrospinal fluid will be successful in exceptional cases only. In patients with AIDS or lymphadenopathy syndrome, the differential diagnosis will have to include - first and foremost - reactivated toxoplasma infection (not newly acquired, as a rule) if central neurological symptoms occur. (orig.)

  17. Cerebral white matter hypoplasia

    International Nuclear Information System (INIS)

    This paper demonstrates the MR imaging findings in children with cerebral white matter hypoplasia (CWMH). The MR studies of four children, aged 3-7 y (mean age, 2.3 y) with a diagnosis of CWMH were reviewed. In all cases multiplanar T1-weighted and T2-weighted spin-echo images were obtained. All children had similar histories of severe developmental delay and nonprogressive neurologic deficits despite normal gestational and birth histories. In two cases there was a history of maternal cocaine abuse. Autopsy correlation was available in one child. The MR images of all four children demonstrated diffuse lack of white matter and enlarged ventricles but normal-appearing gray matter. The corpus callosum, although completely formed, was severely thinned. There was no evidence of gliosis or porencephaly, and the distribution of myelin deposition was normal for age in all cases. Autopsy finding in one child correlated exactly with the MR finding

  18. 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 ...

  19. Regional cerebral blood flow measurement with intravenous [15O]water bolus and [18F]fluoromethane inhalation

    International Nuclear Information System (INIS)

    In 20 patients with ischemic cerebrovascular disease, classic migraine, or angiomas, we compared paired dynamic positron emission tomographic measurements of regional cerebral blood flow using both [15O]water and [18F]fluoromethane as tracers. Cerebral blood flow was also determined according to the autoradiographic technique with a bolus injection of [15O]water. There were reasonable overall correlations between dynamic [15O]water and [18F]fluoromethane values for cerebral blood flow (r = 0.82) and between dynamic and autoradiographic [15O]water values for cerebral blood flow (r = 0.83). We found a close correspondence between abnormal pathologic findings and visually evaluated cerebral blood flow tomograms obtained with the two tracers. On average, dynamic [15O]water cerebral blood flow was 6% lower than that measured with [18F]fluoromethane. There also was a general trend toward a greater underestimation with [15O]water in high-flow areas, particularly in hyperemic areas, probably due to incomplete first-pass extraction of [15O]water. Underestimation was not detected in low-flow areas or in the cerebellum. Absolute cerebral blood flow values were less closely correlated between tracers and techniques than cerebral blood flow patterns. The variability of the relation between absolute flow values was probably caused by confounding effects of the variation in the circulatory delay time. The autoradiographic technique was most sensitive to this type error

  20. 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

    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......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...... subjects. Blood flow was measured by the local 133Xenon washout technique. Mean arterial blood pressure was reduced by a maximum of 23 mmHg by elevating the limb above heart level and elevating to a maximum of 70 mmHg by head-up tilt; in the latter position venous pressure was kept constant and low by...

  1. Autoregulation of PhoP/PhoQ and positive regulation of the cyclic AMP receptor protein-cyclic AMP complex by PhoP in Yersinia pestis.

    Science.gov (United States)

    Zhang, Yiquan; Wang, Li; Han, Yanping; Yan, Yanfeng; Tan, Yafang; Zhou, Lei; Cui, Yujun; Du, Zongmin; Wang, Xiaoyi; Bi, Yujing; Yang, Huiying; Song, Yajun; Zhang, Pingping; Zhou, Dongsheng; Yang, Ruifu

    2013-03-01

    Yersinia pestis is one of the most dangerous bacterial pathogens. PhoP and cyclic AMP receptor protein (CRP) are global regulators of Y. pestis, and they control two distinct regulons that contain multiple virulence-related genes. The PhoP regulator and its cognate sensor PhoQ constitute a two-component regulatory system. The regulatory activity of CRP is triggered only by binding to its cofactor cAMP, which is synthesized from ATP by adenylyl cyclase (encoded by cyaA). However, the association between the two regulatory systems PhoP/PhoQ and CRP-cAMP is still not understood for Y. pestis. In the present work, the four consecutive genes YPO1635, phoP, phoQ, and YPO1632 were found to constitute an operon, YPO1635-phoPQ-YPO1632, transcribed as a single primary RNA, whereas the last three genes comprised another operon, phoPQ-YPO1632, transcribed with two adjacent transcriptional starts. Through direct PhoP-target promoter association, the transcription of these two operons was stimulated and repressed by PhoP, respectively; thus, both positive autoregulation and negative autoregulation of PhoP/PhoQ were detected. In addition, PhoP acted as a direct transcriptional activator of crp and cyaA. The translational/transcriptional start sites, promoter -10 and -35 elements, PhoP sites, and PhoP box-like sequences were determined for these PhoP-dependent genes, providing a map of the PhoP-target promoter interaction. The CRP and PhoP regulons have evolved to merge into a single regulatory cascade in Y. pestis because of the direct regulatory association between PhoP/PhoQ and CRP-cAMP. PMID:23264579

  2. [The pathogenetic prerequisites for the application of the general magnetic therapy in the children presenting with cerebral ischemia].

    Science.gov (United States)

    Denisova, O I; Davydkin, N F; Kulikov, A G

    2014-01-01

    This article presents the analysis of the current literature and the original data of the authors providing the rationale for the use of magnetic therapy for the treatment of the children presenting with cerebral ischemia taking into consideration pathogenesis of this disease. It is demonstrated that the application of the general magnetic field decreases the tone of the cerebral vessels and improves blood flow to the brain which increases resistance to cerebral hypoxia. The results of investigations into the microcirculatory changes and liquor dynamics in conjunction with the ventriculometric measurements give evidence of the effectiveness of the combined treatment of cerebral ischemia making use of general magnetic therapy. PMID:25536760

  3. Anestesia e paralisia cerebral Anestesia y parálisis cerebral Anesthesia and cerebral palsy

    OpenAIRE

    Március Vinícius M Maranhão

    2005-01-01

    JUSTIFICATIVA E OBJETIVOS: A paralisia cerebral (PC) é uma doença não progressiva decorrente de lesão no sistema nervoso central, levando a um comprometimento motor do paciente. O portador de PC freqüentemente é submetido a procedimentos cirúrgicos devido a doenças usuais e situações particulares decorrentes da paralisia cerebral. Foi objetivo deste artigo revisar aspectos da paralisia cerebral de interesse para o anestesiologista, permitindo um adequado manuseio pré, intra e pós-operatório n...

  4. Diagnostic Assessment of Cerebral Palsy

    OpenAIRE

    J Gordon Millichap

    2004-01-01

    The Quality Standards Subcommittee of the American Academy of Neurology and the Practice Committee of the Child Neurology Society have developed practice parameters for the diagnosis of cerebral palsy (CP).

  5. Learn More About Cerebral Palsy

    Centers for Disease Control (CDC) Podcasts

    2008-03-30

    This podcast describes the causes, preventions, types, and signs and symptoms of cerebral palsy.  Created: 3/30/2008 by National Center on Birth Defects and Developmental Disabilities.   Date Released: 3/21/2008.

  6. Diagnostic Assessment of Cerebral Palsy

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-04-01

    Full Text Available The Quality Standards Subcommittee of the American Academy of Neurology and the Practice Committee of the Child Neurology Society have developed practice parameters for the diagnosis of cerebral palsy (CP.

  7. Cerebral blood flow and carbon dioxide reactivity in children with bacterial meningitis

    International Nuclear Information System (INIS)

    We examined total and regional cerebral blood flow (CBF) by stable xenon computed tomography in 20 seriously ill children with acute bacterial meningitis to determine whether CBF was reduced and to examine the changes in CBF during hyperventilation. In 13 children, total CBF was normal (62 +/- 20 ml/min/100 gm) but marked local variability of flow was seen. In five other children, total CBF was significantly reduced (26 +/- 10 ml/min/100 gm; p less than 0.05), with flow reduced more in white matter (8 +/- 5 ml/min/100 gm) than in gray matter (30 +/- 15 ml/min/100 gm). Autoregulation of CBF appeared to be present in these 18 children within a range of mean arterial blood pressure from 56 to 102 mm Hg. In the remaining two infants, brain dead within the first 24 hours, total flow was uniformly absent, averaging 3 +/- 3 ml/min/100 gm. In seven children, CBF was determined at two carbon dioxide tension (PCO2) levels: 40 (+/- 3) mm Hg and 29 (+/- 3) mm Hg. In six children, total CBF decreased 33%, from 52 (+/- 25) to 35 (+/- 15) ml/min/100 gm; the mean percentage of change in CBF per millimeter of mercury of PCO2 was 3.0%. Regional variability of perfusion to changes in PCO2 was marked in all six children. The percentage of change in CBF per millimeter of mercury of PCO2 was similar in frontal gray matter (3.1%) but higher in white matter (4.5%). In the seventh patient a paradoxical response was observed; total and regional CBF increased 25% after hyperventilation. Our findings demonstrate that (1) CBF in children with bacterial meningitis may be substantially decreased globally, with even more variability noted regionally, (2) autoregulation of CBF is preserved, (3) CBF/CO2 responsitivity varies among patients and in different regions of the brain in the same patient, and (4) hyperventilation can reduce CBF below ischemic thresholds

  8. Cerebral venous thrombosis: diagnosis dilemma

    OpenAIRE

    2011-01-01

    Cerebral venous thrombosis is increasing common disease in daily practice with sharing clinical nonspecific symptoms. This disorder is potentially lethal but treatable, oftenly it was overlooked in both clinical and radiologic in routine practice. Whenever, clinical suspected, prompt investigation by noninvasive imaging Magnetic resonance (MR) or advanced modilities such as cerebral venous thrombosis (CVT), MRV (MR Venography) will helpful in prompt diagnosis and treatment. These imaging moda...

  9. Cerebral involvement in Whipple's disease

    International Nuclear Information System (INIS)

    Whipple's disease is a rare protean disease. Cerebral involvement occurs in ten percent of the cases. CCT findings in two patients with cerebral symptoms are presented. There was an unspecific atrophy in one patient. Patient two had hydrocephalus occlusus and a temporal lesion enhanced by contrast agent. A specific diagnosis on the sole basis of the CCT without additional clinical data does not seem possible. (orig.)

  10. Sirt1 in cerebral ischemia

    OpenAIRE

    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 seve...

  11. NEYROPSYCHOLOGICAL CONSECUENCES OF CEREBRAL PALSY

    OpenAIRE

    ANA MARÍA NAVARRO MELENDRO; ANDREA PATRICIA RESTREPO IBIZA

    2005-01-01

    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 ...

  12. Cerebral candidiasis. Computed tomography appearance

    International Nuclear Information System (INIS)

    A three year old child who had been suffering from oral candidiasis since the age of 1 year presented with osteitis of the clavicle, 2 cerebral frontal abscesses and an occipital abscess which extended across the calvaria and was associated with osteolysis. Histological and microbiological studies following surgery confirmed the diagnosis of candidiasis in this girl who was found to have IgA immunodefinciency. The authors report the computed tomographic appearance of the cerebral lesions and review the literature. (orig.)

  13. Cerebral candidiasis. Computed tomography appearance

    Energy Technology Data Exchange (ETDEWEB)

    Chaabane, M.; Ladeb, M.F.; Bouhaouala, M.H.; Ben Hammouda, M.; Ataalah, R.; Gannouni, A.; Krifa, H.

    1989-07-01

    A three year old child who had been suffering from oral candidiasis since the age of 1 year presented with osteitis of the clavicle, 2 cerebral frontal abscesses and an occipital abscess which extended across the calvaria and was associated with osteolysis. Histological and microbiological studies following surgery confirmed the diagnosis of candidiasis in this girl who was found to have IgA immunodefinciency. The authors report the computed tomographic appearance of the cerebral lesions and review the literature. (orig.).

  14. Cerebral palsy: classification and etiology

    OpenAIRE

    Bialik, Gad M.; Givon, Uri

    2004-01-01

    Cerebral palsy (CP), a common condition of abnormalities in the brain, arises early in life. Since the term was first introduced in 1843, many authors have tried to define and classify CP. The most recent definition was released by the American Academy for Cerebral Palsy and Developmental Medicine (AACPDM) in 2005. This article summarizes the latest and familiar classifications of, and etiologies associated with CP.

  15. CEREBRAL PALSY : ANTENATAL RISK FACTORS

    OpenAIRE

    Srinivasa Rao; Vidyullatha; Subbalakshmi

    2015-01-01

    INTRODUCTION: Cerebral palsy (CP) is a group of permanent movement disorders that appear in early childhood. Cerebral palsy is caused by abnormal development or damage to the parts of the brain that control movement, balance, and posture. Most often the problems occur during pregnancy; however, they may also occur during childbirth, or shortly after birth. Often the cause is unknown. AIM: To study the different antenatal maternal risk factors associated with cere...

  16. Bone age in cerebral palsy

    OpenAIRE

    Miranda, Eduardo Régis de Alencar Bona; Palmieri, Maurício D'arc; de Assumpção, Rodrigo Montezuma César; Yamada, Helder Henzo; Rancan, Daniela Regina; Fucs, Patrícia Maria de Moraes Barros

    2013-01-01

    Objective To compare the chronological age and bone age among cerebral palsy patients in the outpatient clinic and its correlation with the type of neurological involvement, gender and functional status. Methods 401 patients with spastic cerebral palsy, and ages ranging from three months to 20 years old, submitted to radiological examination for bone age and analyzed by two independent observers according Greulich & Pyle. Results In the topographic distribution, there was a significant delay (p

  17. Cerebral small-resistance artery structure and cerebral blood flow in normotensive subjects and hypertensive patients

    Energy Technology Data Exchange (ETDEWEB)

    De Ciuceis, Carolina; Porteri, Enzo; Rizzoni, Damiano; Boari, Gianluca E.M.; Rosei, Enrico Agabiti [University of Brescia, Clinica Medica, Department of Clinical and Experimental Sciences, Brescia (Italy); Cornali, Claudio; Mardighian, Dikran; Fontanella, Marco M. [University of Brescia, Section of Neurosurgery, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy); Pinardi, Chiara [Spedali Civili, Medical Physics Unit, Brescia (Italy); University of Brescia, Section of Neuroradiology, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy); Rodella, Luigi F.; Rezzani, Rita [University of Brescia, Section of Anatomy, Department of Clinical and Experimental Sciences, Brescia (Italy); Gasparotti, Roberto [University of Brescia, Section of Neurosurgery, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy); University of Brescia, Section of Neuroradiology, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy)

    2014-12-15

    The aim of this study was to prospectively investigate whether the structure of cerebral small-resistance arteries is related to cerebral perfusion parameters as measured with dynamic susceptibility-weighted contrast magnetic resonance imaging (DSC-MRI) in a selected cohort of hypertensive and normotensive patients. Ten hypertensive and 10 normotensive patients were included in the study. All patients underwent neurosurgical intervention for an intracranial tumor and were investigated with DSC-MRI at 1.5 T. Cerebral small-resistance arteries were dissected from a small portion of morphologically normal cerebral tissue and mounted on an isometric myograph for the measurement of the media-to-lumen (M/L) ratio. A quantitative assessment of cerebral blood flow (CBF) and volume (CBV) was performed with a region-of-interest approach. Correlation coefficients were calculated for normally distributed variables. The institutional review board approved the study, and informed consent was obtained from all patients. Compared with normotensive subjects, hypertensive patients had significantly lower regional CBF (mL/100 g/min) in the cortical grey matter (55.63 ± 1.90 vs 58.37 ± 2.19, p < 0.05), basal ganglia (53.34 ± 4.39 vs 58.22. ± 4.33, p < 0.05), thalami (50.65 ± 3.23 vs 57.56 ± 4.45, p < 0.01), subcortical white matter (19.32 ± 2.54 vs 22.24 ± 1.9, p < 0.05), greater M/L ratio (0.099 ± 0.013 vs 0.085 ± 0.012, p < 0.05), and lower microvessel density (1.66 ± 0.67 vs 2.52 ± 1.28, p < 0.05). A statistically significant negative correlation was observed between M/L ratio of cerebral arteries and CBF in the cortical grey matter (r = -0.516, p < 0.05), basal ganglia (r = -0.521, p < 0.05), thalami (r = -0.527 p < 0.05), and subcortical white matter (r = -0.612, p < 0.01). Our results indicate that microvascular structure might play a role in controlling CBF, with possible clinical consequences. (orig.)

  18. Gene expression profiling in the human middle cerebral artery after cerebral ischemia.

    Science.gov (United States)

    Vikman, P; Edvinsson, L

    2006-12-01

    We have investigated the gene expression in human middle cerebral artery (MCA) after ischemia. Ischemic stroke affects the perfusion in the affected area and experimental cerebral ischemia results in upregulation of vasopressor receptors in the MCA leading to the ischemic area. We obtained human MCA samples distributing to the ischemic area, 7-10 days post-stroke. The gene expression was examined with real-time polymerase chain reaction (PCR) and microarray, proteins were studied with immunohistochemistry. We investigated genes previously shown to be upregulated in animal models of cerebral ischemia (e.g. ET(A), ET(B), AT1, AT2, and 5-HT(2A/1B/1D)). Their mRNA expression was increased compared with controls, consistent with findings in experimental stroke. Immunohistochemistry showed upregulation of the receptors localized on the smooth muscle cells. The gene expression was profiled with microarray and seven genes chosen for further investigation with real-time PCR; ELK3, LY64, Metallothionin IG, POU3F4, Actin alpha2, RhoA and smoothelin. Six of these were regulated the same way when confirming array expression with real-time PCR. Gene expression studies in the human MCA leading to the ischemic region is similar to that seen after MCA occlusion in rats. We found new genes that support the dynamic changes that occur in the MCA distributing to the ischemic region. PMID:17116215

  19. 中文版儿童作业疗法认知功能动态评定量表评定脑性瘫痪患儿认知功能的效度研究①%Validity of Dynamic Occupational Therapy Cognitive Assessment for Children on Cognitive Function of Children with Cerebral Pal- sy

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      目的了解中文版儿童作业疗法认知功能动态评定量表(DOTCA-Ch)是否能反映脑瘫患儿的认知功能情况。方法30例脑瘫儿童在1周内由经过培训的康复医学研究生采用DOTCA-Ch和中国比内智力测验分别进行认知功能评定。DOTCA-Ch总分、分测验得分分别与中国比内智力测验得分进行相关性分析。结果 DOTCA-Ch总分、定向和思维操作与IQ值高度相关,空间知觉、运用和视运动组织分测验与IQ值相关度较低。结论 DOTCA-Ch能更全面评定儿童认知功能情况。%Objective To study the validity of Dynamic Occupational Therapy Cognitive Assessment for Children (DOTCA-Ch) on the cognitive function of children with cerebral palsy. Methods 30 children with cerebral palsy were assessed with DOTCA-Ch and Chinese Bi-net Test of Intelligence by trained rehabilitation medicine graduates within 1 week. The correlation between these tests were analyzed. Re-sults The total DOTCA-Ch scores, spatial orientation and thought operation function were strongly correlated with IQ, while spatial percep-tion, praxis and optomotor tissue were slightly correlated with IQ. Conclusion DOTCA-Ch can comprehensively assess the cognitive func-tion of children with cerebral palsy.

  20. Pathogenesis of cerebral malaria

    International Nuclear Information System (INIS)

    Full text: Cerebral Malaria (CM) is the most severe complication of malaria and a major cause of death. The mechanisms underlying human CM pathogenesis might be due to mechanical cause, as demonstrated by cytoadherence of parasitised erythrocytes pRB, or to excessive cytokine production by the host in response to Plasmodium falciparum, or a combination of the two together with neuronal injury by malaria toxins. Antibody response, genetic traits and other factors have been proposed to explain why only some episodes have life-threatening complications. The microvascular endothelial cell is a major target of inflammatory cytokines overproduced in infectious diseases. Fatal CM is associated with widespread induction of endothelial activation markers, with significant higher levels of ICAM, VCAM and E-selectin expression on vessels in the brain. 199 patients were admitted at the hospital and were classified with malaria-based neurological disfunctions, such as acute psychosis, ataxia, hallucinations, fever and convulsions, prostration or coma. On a flow chart, 65 of those patients with the most acute syndromes mentioned above, were found to have negative BSN (blood slide), compared to 124 where the BSN showed to be positive. Identically to the 10 other patients from the severe form group, also presented positive BSN. The condition of some of these two subgroup patients (15), will later evolve into a more severe form with acute neurological disfunctions attributed to the cerebral malaria. The interesting aspect in regards to the 65 patients considered as having CM, upon severe manifestations of the disease, show no or little peripheral parasitemia. This fact confirms our experimental conclusion that, in the process of pRB adhesion to the microvessels of the brain, they are sequestered by monocytes and platelets, leading to vessel rupture. This fact could be an explanation of the lower % of circulating pRB and low peripheral parasitemia. There is a relationship between

  1. Effects of Hyperglycemia and Effects of Ketosis on Cerebral Perfusion, Cerebral Water Distribution, and Cerebral Metabolism

    OpenAIRE

    Glaser, Nicole; Ngo, Catherine; Anderson, Steven; Yuen, Natalie; Trifu, Alexandra; O’Donnell, Martha

    2012-01-01

    Diabetic ketoacidosis (DKA) may cause brain injuries in children. The mechanisms responsible are difficult to elucidate because DKA involves multiple metabolic derangements. We aimed to determine the independent effects of hyperglycemia and ketosis on cerebral metabolism, blood flow, and water distribution. We used magnetic resonance spectroscopy to measure ratios of cerebral metabolites (ATP to inorganic phosphate [Pi], phosphocreatine [PCr] to Pi, N-acetyl aspartate [NAA] to creatine [Cr], ...

  2. Reliability of “Modified timed up and go” test in children with cerebral palsy

    OpenAIRE

    Sanjivani N Dhote; Prema A Khatri; Suvarna S Ganvir

    2012-01-01

    Background: Timed up and go (TUG) is a quick test used in clinical practice as an outcome measure to assess functional ambulatory mobility or dynamic balance in adults. However, little information is available on TUG test used in cerebral palsy. Hence, the purpose of our study was to assess the intra-rater reliability of TUG test in cerebral palsy children. Aim and Objective: To assess within-session and test-retest reliability after 1 week of TUG test in cerebral palsy children. Setting and ...

  3. Cerebral edema associated with acute hepatic failure.

    Directory of Open Access Journals (Sweden)

    Fujiwara,Masachika

    1985-02-01

    Full Text Available The clinicopathological findings of cerebral edema were investigated in patients with acute hepatic failure autopsied at Okayama University Hospital between 1970 and 1980 retrospectively. Nine (64% of 14 hepatic failure cases were found to have cerebral edema during a post-mortem examination of the brain. Clinical features of the patients with cerebral edema were not significantly different from those of the patients without cerebral edema. However, general convulsions were observed more frequently in patients later found to have cerebral edema. Moreover, the length of time from deep coma to death was much shorter in the brain edema cases with cerebral herniation than without herniation.

  4. Asymptomatic ischemic cerebral lesions

    International Nuclear Information System (INIS)

    For the purpose of studying the incidence, pathomorphology and etiology of asymptomatic ischemic cerebral lesions, we carried out a brain MRI study on 65 patients with diabetes mellitus accompanied with hypertension who are thought to belong to a high risk group of ischemic cerebrovascular diseases. Excluding the abnormality of tendon reflex due to diabetic neuropathy, sixty percent of the total patients had some mild neurological signs and symptoms, most of them was discrepancy in tendon reflex. The percentage of the patients in whom MRI disclosed some abnormalities was as high as 70%, they were lacunar stroke, multiple lacunar state, cortical infarct, and patchy high signal lesions visible only in the T2 weighted image. Lacunes or these patchy high signal lesions (considered to be the dilatation of the perivascular space or true lacunes) tended to be found along the border zone or the terminal zone. These results indicate that asymptomatic patients in whom MRI discloses the abnormalities should be considered as candidates for the future onset of multi-infarct. (author)

  5. Cerebral trypanosomiasis and AIDS

    Directory of Open Access Journals (Sweden)

    Antunes Apio Claudio Martins

    2002-01-01

    Full Text Available A 36 year-old black female, complaining of headache of one month's duration presented with nausea, vomiting, somnolence, short memory problems, loss of weight, and no fever history. Smoker, intravenous drugs abuser, promiscuous lifestyle. Physical examination: left homonimous hemianopsia, left hemiparesis, no papilledema, diffuse hyperreflexia, slowness of movements. Brain CT scan: tumor-like lesion in the splenium of the corpus calosum, measuring 3.5 x 1.4 cm, with heterogeneous enhancing pattern, sugesting a primary CNS tumor. Due to the possibility of CNS infection, a lumbar puncture disclosed an opening pressure of 380 mmH(20; 11 white cells (lymphocytes; glucose 18 mg/dl (serum glucose 73 mg/dl; proteins 139 mg/dl; presence of Trypanosoma parasites. Serum Elisa-HIV tests turned out to be positive. Treatment with benznidazole dramatically improved clinical and radiographic picture, but the patient died 6 weeks later because of respiratory failure. T. cruzi infection of the CNS is a rare disease, but we have an increasing number of cases in HIV immunecompromised patients. Diagnosis by direct observation of CSF is uncommon, and most of the cases are diagnosed by pathological examination. It is a highly lethal disease, even when properly diagnosed and treated. This article intends to include cerebral trypanosomiasis in the differential diagnosis of intracranial space-occupying lesions, especially in immunecompromised patients from endemic regions.

  6. [Plasma osmolarity and cerebral volume].

    Science.gov (United States)

    Boulard, G

    2001-02-01

    Under normal physiological conditions, the osmolarity of extracellular fluids (ECFs) and natremia are controlled by two regulatory mechanisms modulating the water balance and sodium outflow from information collected by the osmoreceptors and baroreceptors, respectively. As well, under normal physiological conditions, water and electrolytes of brain ECFs are secreted by the endothelial cells of brain capillaries. Furthermore, isotonicity is present on both sides of the blood-brain barrier. In the event of systemic osmolarity disorders, water transport subject to osmosis laws occurs at the level of the blood-brain barrier. In the case of plasmatic hyperosmolarity cerebral dehydration is observed, while cerebral edema occurs in the contrary case. However, plasmatic osmolarity disorders have less effect on the cerebral volume when their introduction is slow. Experimentation in acute conditions shows that measured variations of the cerebral water content are lower than calculated variations, thus suggesting the existence of an adaptive mechanism, that is, the cerebral osmoregulation which limits the variation of the volume of brain cells by modulating their osmoactive molecule content. These osmoactive molecules are, on the one hand, the electrolytes, which are early and rapidly mobilized, and, on the other hand, the organic osmoles (amino acids, etc.), whose secretion is slower and delayed. This phenomenon should be taken into account in the treatment of osmolarity disorders. Thus, the related-risk of treatment for natremia disorders is therapeutic reversal of the osmotic gradient at the level of the blood-brain barrier. This reversal, which corresponds to a second osmotic stress, requires the implementation of a new procedure of cerebral osmoregulation in the opposite direction of the preceding one. As successive osmotic stresses decrease the effectiveness of brain osmoregulation, the risk for cerebral dehydration and pontine myelinolysis increases when the treatment

  7. Middle cerebral artery flow velocity and blood flow during exercise and muscle ischemia in humans

    DEFF Research Database (Denmark)

    Jørgensen, L G; Perko, M; Hanel, B; Schroeder, T V; Secher, N H

    1992-01-01

    Changes in middle cerebral artery flow velocity (Vmean), measured by transcranial Doppler ultrasound, were used to determine whether increases in mean arterial pressure (MAP) or brain activation enhance cerebral perfusion during exercise. We also evaluated the role of "central command......," mechanoreceptors, and/or muscle "metaboreceptors" on cerebral perfusion. Ten healthy subjects performed two levels of dynamic exercise corresponding to a heart rate of 110 (range 89-134) and 148 (129-170) beats/min, respectively, and exhaustive one-legged static knee extension. Measurements were continued during 2......-2.5 min of muscle ischemia. MAP increased similarly during static [114 (102-133) mmHg] and heavy dynamic exercise [121 (104-136) mmHg] and increased during muscle ischemia after dynamic exercise. During heavy dynamic exercise, Vmean increased 24% (10-47%; P less than 0.01) over approximately 3 min despite...

  8. Vascular permeability in cerebral cavernous malformations

    DEFF Research Database (Denmark)

    Mikati, Abdul G; Khanna, Omaditya; Zhang, Lingjiao;

    2015-01-01

    Patients with the familial form of cerebral cavernous malformations (CCMs) are haploinsufficient for the CCM1, CCM2, or CCM3 gene. Loss of corresponding CCM proteins increases RhoA kinase-mediated endothelial permeability in vitro, and in mouse brains in vivo. A prospective case-controlled observ......Patients with the familial form of cerebral cavernous malformations (CCMs) are haploinsufficient for the CCM1, CCM2, or CCM3 gene. Loss of corresponding CCM proteins increases RhoA kinase-mediated endothelial permeability in vitro, and in mouse brains in vivo. A prospective case......-controlled observational study investigated whether the brains of human subjects with familial CCM show vascular hyperpermeability by dynamic contrast-enhanced quantitative perfusion magnetic resonance imaging, in comparison with CCM cases without familial disease, and whether lesional or brain vascular permeability...... correlates with CCM disease activity. Permeability in white matter far (WMF) from lesions was significantly greater in familial than in sporadic cases, but was similar in CCM lesions. Permeability in WMF increased with age in sporadic patients, but not in familial cases. Patients with more aggressive...

  9. Monitoring cerebral perfusion after subarachnoid hemorrhage using CT

    International Nuclear Information System (INIS)

    The aim of this prospective study was to assess the feasibility and diagnostic relevance of repetitive dynamic (contrast-enhanced) CT measurements of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) in the first 3 weeks after aneurysmal subarachnoid hemorrhage (SAH). In 15 patients with SAH, 59 dynamic CT studies including 944 regions of interest (ROI) were analyzed. The results were correlated with the clinical course and time after the event and the occurrence of vasospasm. Values for the entire series were 33.8 ± 19.3 ml/100 g/min (CBF), 3.3 ± 1.3 ml/100 g (CBV), and 7.3 ± 3.9 s (MTT). Significant differences in CBF and CBV were found between ROI in grey and white matter, with time after the event, between patients with significant and absent or minor vasospasm, and between patients with and without a presumed vasospasm-related infarct. (orig.)

  10. Applications of dynamical systems in biology and medicine

    CERN Document Server

    Radunskaya, Ami

    2015-01-01

    This volume highlights problems from a range of biological and medical applications that can be interpreted as questions about system behavior or control.  Topics include drug resistance in cancer and malaria, biological fluid dynamics, auto-regulation in the kidney, anti-coagulation therapy, evolutionary diversification and photo-transduction.  Mathematical techniques used to describe and investigate these biological and medical problems include ordinary, partial and stochastic differentiation equations, hybrid discrete-continuous approaches, as well as 2 and 3D numerical simulation. .

  11. What You Should Know about Cerebral Aneurysms

    Science.gov (United States)

    ... T. Quiz 5 Things to Know About Stroke What You Should Know About Cerebral Aneurysms Updated:Jun ... Damage Treatments Click image to view an animation What is a cerebral aneurysm? An aneurysm is a ...

  12. Cerebral abscess in the recently born

    International Nuclear Information System (INIS)

    An unusual case of cerebral abscess in a newborn is reported. Emphasis is made in the paramount importance of its early diagnosis; mainly with imaging modalities like cerebral ultrasound and CT, in order to establisher the most appropriate therapy

  13. Middle cerebral artery blood velocity during rowing

    DEFF Research Database (Denmark)

    Secher, Niels Henry; Pott, F; Knudsen, L.;

    1997-01-01

    original,arterial blood pressure,central venous pressure,cerebral blood flow, exercise, transcranial Doppler......original,arterial blood pressure,central venous pressure,cerebral blood flow, exercise, transcranial Doppler...

  14. Primary cerebral lymphoma

    International Nuclear Information System (INIS)

    The aim of this study is to compare the survival of the patients treated with radiotherapy alone vs. patients treated with a combined schedule of radio-chemotherapy. Our results will be compared with currently published data and main prognostic factors will be briefly discussed. Patients and methods: Between 1974 and 1990, 27 cases of primary cerebral lymphoma were diagnosed at our institution. All patients had biopsy-proven disease, the pathology of which was reviewed for this study. Results: The overall median survival time was 24 months and one-, two- and three-year overall survival was 59, 46 and 29% respectively. The median radiation dose was 46 Gy, ranging from 19.5 to 60 Gy. The median dose per fraction was 2 Gy (ranging from 1.61 to 3 Gy). The median elapsed treatment time was 32 days (ranging from three to 45 days). We were not able to demonstrate any statistically significant difference between patients who received radiotherapy alone (n = 14, median survival time = 24 months) and those who received a combination of chemotherapy and radiotherapy (n = 11, median survival time = 30 months), (p = 0.4). Prognostic factors of survival were tested using a univariate analysis (Wilcoxon test). Parameters such as mass appearance (unilobular, p = 0.048), performance status at the time of the diagnosis (0 to 1, p = 0.014), and CT imaging (hypodense, p = 0.043) influenced positively survival. Centroblastic histology (Kiel) was found associated with a negative prognosis (p = 0.043). (orig./MG)

  15. Dynamics

    CERN Document Server

    Goodman, Lawrence E

    2001-01-01

    Beginning text presents complete theoretical treatment of mechanical model systems and deals with technological applications. Topics include introduction to calculus of vectors, particle motion, dynamics of particle systems and plane rigid bodies, technical applications in plane motions, theory of mechanical vibrations, and more. Exercises and answers appear in each chapter.

  16. Cerebral edema associated with acute hepatic failure.

    OpenAIRE

    Fujiwara, Masachika; Watanabe,Akiharu; Yamauchi,Yasuhiko; Hashimoto, Makoto; Nakatsukasa, Harushige; Kobayashi, Michio; Higashi,Toshihiro; Nagashima,Hideo

    1985-01-01

    The clinicopathological findings of cerebral edema were investigated in patients with acute hepatic failure autopsied at Okayama University Hospital between 1970 and 1980 retrospectively. Nine (64%) of 14 hepatic failure cases were found to have cerebral edema during a post-mortem examination of the brain. Clinical features of the patients with cerebral edema were not significantly different from those of the patients without cerebral edema. However, general convulsions were observed more fre...

  17. Cerebritis: an unusual complication of Klebsiella pneumoniae.

    Science.gov (United States)

    Majumdar, Mainak; Simes, David C; Prabha, Ramesh D

    2009-01-01

    Cerebritis is part of a continuum of brain infection and is difficult to diagnose. Cerebritis caused by Klebsiella in immunocompetent adults without predisposing factors such as neurosurgery or penetrating brain injury has not been reported before. We report a case of Klebsiella cerebritis in an adult patient with a proven extracranial focus of infection. We suggest considering cerebritis as a differential diagnosis for altered level of consciousness in patients of severe sepsis, even if an extracranial source of infection is proven. PMID:19881180

  18. Cerebritis: An unusual complication of Klebsiella pneumoniae

    OpenAIRE

    Majumdar, Mainak; Simes1, David C.; Prabha1, Ramesh D.

    2009-01-01

    Cerebritis is part of a continuum of brain infection and is difficult to diagnose. Cerebritis caused by Klebsiella in immunocompetent adults without predisposing factors such as neurosurgery or penetrating brain injury has not been reported before. We report a case of Klebsiella cerebritis in an adult patient with a proven extracranial focus of infection. We suggest considering cerebritis as a differential diagnosis for altered level of consciousness in patients of severe sepsis, even if an e...

  19. Cerebritis: An unusual complication of Klebsiella pneumoniae

    Science.gov (United States)

    Majumdar, Mainak; Simes1, David C.; Prabha1, Ramesh D.

    2009-01-01

    Cerebritis is part of a continuum of brain infection and is difficult to diagnose. Cerebritis caused by Klebsiella in immunocompetent adults without predisposing factors such as neurosurgery or penetrating brain injury has not been reported before. We report a case of Klebsiella cerebritis in an adult patient with a proven extracranial focus of infection. We suggest considering cerebritis as a differential diagnosis for altered level of consciousness in patients of severe sepsis, even if an extracranial source of infection is proven. PMID:19881180

  20. 脑血流低灌注老龄大鼠中脑皮质血流的改变与血清总胆固醇和高密度脂蛋白的动态变化%Dynamic changes of cortical blood flow and serum total cholesterol and high density lipoprotein in brains of aging rat during cerebral hypoperfusion

    Institute of Scientific and Technical Information of China (English)

    王林辉; 田茗源; 滕志朋; 王晨; 李昱

    2012-01-01

    目的:通过建立脑血流低灌注模型,观察老龄大鼠脑血流的变化以及在脑血流低灌注下血清中总胆固醇(Total cholesterol,TC)和高密度脂蛋白(High density lipoprotein,HDL)的动态变化.方法:采用持久性双侧颈总动脉结扎法(2Vo)致老龄大鼠脑血流灌注不足,测定术后7、14、21、28d大鼠脑皮质血流;检测、比较术后不同时间段大鼠血清中TC和HDL浓度差异.结果:术后第14天大鼠脑颞区血流出现明显减少;术后21、28d大鼠脑局部皮质血管有再生侧支形成,大鼠脑颞区血流仍未恢复;术后第14天血清中HDL、TC含量明显高于假手术组(P<0.05),随着缺血时间延长,又逐渐降低.结论:血清TC和HDL浓度在脑缺血灌注不足的不同时间段经历了先增强后减弱的动态变化,提示脑血流低灌注老龄大鼠因大脑血流灌注不足可出现体内胆固醇代谢失衡并出现应激调节现象.%Objective: To investigate the change of cortical blood flow and the dynamic changes of serum total cholesterol(TC ) and high density lipoprotein(HDL) in brains of aging rat during cerebral ischemic injury. Methods:The model of aging rats with cerebral hy-poperfusion was successfully constructed by persistent bilateral common carotid artery ligation(2V0). The cortical blood flow and the concentration of serum TC and HDL at different time points were determined and compared. Results: Compared with the sham-operated group,the temporal blood flow was significantly decreased in 14 d group. But the collateral vessels were gradually regenerated and formed in local brain,while the temporal blood flow was restored in 21 d and 28 d group. The concentration of HDL and TC was significantly higher in 14 d group than in the sham-operated group (P<0.05), and both of them were decreased with the extention of ischemia time. Conclusions:The serum TC and HDL concentration undergo dynamic changes-increasing first and then decreasing during the process

  1. Mechanisms of cerebral radiation syndrome

    International Nuclear Information System (INIS)

    Ability of exogenous succinate to prevent the postradiation violations in neuronal respiration and to correct the manifestations of cerebral radiation syndrome is studied. Rats-males were used for experiments. RUM-17 X-ray therapeutic apparatus was applied for irradiation at the dose rate of 25 Gy/min. It is established that the neurological violations in rats following X-ray exposure at 150 Gy dose depend on cerebral energy deficiency connected with NAD neuronal pool depletion. Efficiency is demonstrated of two approaches to the prevention of cerebral radiation syndrome providing: a) retroinhibition of adenosine diphosphoribosyltransferase, b) administration of NAD - independently oxidated bioenergetic substrate. It is marked that the application of sodium succinate may be of special interest in the cases when the dose for forthcoming irradiation is unknown

  2. Neuroevolutional Approach to Cerebral Palsy and Speech.

    Science.gov (United States)

    Mysak, Edward D.

    Intended for cerebral palsy specialists, the book emphasizes the contribution that a neuroevolutional approach to therapy can make to habilitation goals of the child with cerebral palsy and applies the basic principles of the Bobath approach to therapy. The first section discusses cerebral palsy as a reflection of disturbed neuro-ontogenisis and…

  3. Cerebral toksoplasmose primaert diagnosticeret som tumor

    DEFF Research Database (Denmark)

    Cortsen, M E; Skøt, J; Skriver, E B

    1992-01-01

    Three cases of cerebral toxoplasmosis as the presenting manifestation of AIDS are reported. The initial diagnoses were brain tumors because of the cerebral mass lesions which resembled glioblastoma. In the light of the increasing occurrence of AIDS, attention is drawn to cerebral toxoplasmosis...

  4. Cerebral vasculitis associated with cocaine abuse

    International Nuclear Information System (INIS)

    A case of cerebral vasculitis in a previously healthy 22-year-old man with a history of cocaine abuse is described. Cerebral angiograms showed evidence of vasculitis. A search for possible causes other than cocaine produced no results. The authors include cocaine with methamphetamines, heroin, and ephedrine as illicit drugs that can cause cerebral vasculitis

  5. Laser Speckle Imaging of Cerebral Blood Flow

    Science.gov (United States)

    Luo, Qingming; Jiang, Chao; Li, Pengcheng; Cheng, Haiying; Wang, Zhen; Wang, Zheng; Tuchin, Valery V.

    Monitoring the spatio-temporal characteristics of cerebral blood flow (CBF) is crucial for studying the normal and pathophysiologic conditions of brain metabolism. By illuminating the cortex with laser light and imaging the resulting speckle pattern, relative CBF images with tens of microns spatial and millisecond temporal resolution can be obtained. In this chapter, a laser speckle imaging (LSI) method for monitoring dynamic, high-resolution CBF is introduced. To improve the spatial resolution of current LSI, a modified LSI method is proposed. To accelerate the speed of data processing, three LSI data processing frameworks based on graphics processing unit (GPU), digital signal processor (DSP), and field-programmable gate array (FPGA) are also presented. Applications for detecting the changes in local CBF induced by sensory stimulation and thermal stimulation, the influence of a chemical agent on CBF, and the influence of acute hyperglycemia following cortical spreading depression on CBF are given.

  6. Lifetime costs of cerebral palsy

    DEFF Research Database (Denmark)

    Kruse, Marie; Michelsen, Susan Ishøy; Flachs, Esben Meulengracht;

    2009-01-01

    This study quantified the lifetime costs of cerebral palsy (CP) in a register-based setting. It was the first study outside the US to assess the lifetime costs of CP. The lifetime costs attributable to CP were divided into three categories: health care costs, productivity costs, and social costs....... The population analyzed was retrieved from the Danish Cerebral Palsy Register, which covers the eastern part of the country and has registered about half of the Danish population of individuals with CP since 1950. For this study we analyzed 2367 individuals with CP, who were born in 1930 to 2000 and...

  7. Features to validate cerebral toxoplasmosis

    Directory of Open Access Journals (Sweden)

    Carolina da Cunha Correia

    2013-06-01

    Full Text Available Introduction Neurotoxoplasmosis (NT sometimes manifests unusual characteristics. Methods We analyzed 85 patients with NT and AIDS according to clinical, cerebrospinal fluid, cranial magnetic resonance, and polymerase chain reaction (PCR characteristics. Results In 8.5%, focal neurological deficits were absent and 16.4% had single cerebral lesions. Increased sensitivity of PCR for Toxoplasma gondii DNA in the central nervous system was associated with pleocytosis and presence of >4 encephalic lesions. Conclusions Patients with NT may present without focal neurological deficit and NT may occur with presence of a single cerebral lesion. Greater numbers of lesions and greater cellularity in cerebrospinal fluid improve the sensitivity of PCR to T gondii.

  8. The effects of propofol on cerebral perfusion MRI in children

    International Nuclear Information System (INIS)

    The effects of anesthesia are infrequently considered when interpreting pediatric perfusion magnetic resonance imaging (MRI). The objectives of this study were to test for measurable differences in MR measures of cerebral blood flow (CBF) and cerebral blood volume (CBV) between non-sedated and propofol-sedated children, and to identify influential factors. Supratentorial cortical CBF and CBV measured by dynamic susceptibility contrast perfusion MRI in 37 children (1.8-18 years) treated for infratentorial brain tumors receiving propofol (IV, n = 19) or no sedation (NS, n = 18) were compared between groups and correlated with age, hematocrit (Hct), end-tidal CO2 (ETCO2), dose, weight, and history of radiation therapy (RT). The model most predictive of CBF and CBV was identified by multiple linear regression. Anterior cerebral artery (ACA) and middle cerebral artery (MCA) territory CBF were significantly lower, and MCA territory CBV greater (p = 0.03), in IV than NS patients (p = 0.01, 0.04). The usual trend of decreasing CBF with age was reversed with propofol in ACA and MCA territories (r = 0.53, r = 0.47; p 2, hematocrit, or RT. In propofol-sedated children, usual age-related decreases in CBF were reversed, and increases in CBF and CBV were weight-dependent, not previously described. Weight-dependent increases in propofol clearance may diminish suppression of CBF and CBV. Prospective study is required to establish anesthetic-specific models of CBF and CBV in children. (orig.)

  9. Radiosurgery for cerebral cavernomas.

    Science.gov (United States)

    Nagy, G; Kemeny, A A

    2015-09-01

    The role of stereotactic radiosurgery (SRS) in the management of cerebral cavernomas (CCMs) remains controversial. However, during the last decade the increasing knowledge on natural history and numerous publications from SRS centers using modern treatment protocols has been changing the initial resistance of the neurosurgical community. Unfortunately, the quality of publications on CCM SRS remains heterogeneous. Controversies arise from the lack of control groups, the different definition of hemorrhage, heterogeneous patient populations, and poor definition of treatment protocols. The key for proper interpretation of results is the understanding of the natural history of CCMs, which is varied both according to anatomical location and the presence or absence of previous hemorrhage. Hemispheric lesions appear to be more benign with lower annual bleed rate and risk of persisting disability, whereas those found in the thalamus, basal ganglia and brainstem typically have higher rebleed risk resulting in higher cumulative morbidity following subsequent hemorrhages. However, we are still unable at presentation to predict the future behavior of an individual lesion. In the present paper we critically review and analyze the modern SRS literature on CCMs. The expanding number of available data with current treatment protocols strongly supports the initial intuition that SRS is an effective treatment alternative for deep-seated CCMs with multiple hemorrhages reducing pretreatment annual rebleed rates from 32% pre-treatment to 1.5% within 2 years after treatment (N.=197). Moreover, it appears to stabilize lesions with no more than one bleed, and it is also effective for CCMs causing therapy resistant epilepsy especially if applied within 3 years after presentation. In modern SRS series the rate of persisting adverse radiation effects is low, resulting only in mild morbidity even in deep-seated lesions (4.16%, N.=376), and morbidity caused by post-treatment hemorrhages is also

  10. What is cerebral small vessel disease?

    International Nuclear Information System (INIS)

    An accumulating amount of evidence suggests that the white matter hyperintensities on T2 weighted brain magnetic resonance imaging predict an increased risk of dementia and gait disturbance. This state has been proposed as cerebral small vessel disease, including leukoaraiosis, Binswanger's disease, lacunar stroke and cerebral microbleeds. However, the concept of cerebral small vessel disease is still obscure. To understand the cerebral small vessel disease, the precise structure and function of cerebral small vessels must be clarified. Cerebral small vessels include several different arteries which have different anatomical structures and functions. Important functions of the cerebral small vessels are blood-brain barrier and perivasucular drainage of interstitial fluid from the brain parenchyma. Cerebral capillaries and glial endfeet, take an important role for these functions. However, the previous pathological investigations on cerebral small vessels have focused on larger arteries than capillaries. Therefore little is known about the pathology of capillaries in small vessel disease. The recent discoveries of genes which cause the cerebral small vessel disease indicate that the cerebral small vessel diseases are caused by a distinct molecular mechanism. One of the pathological findings in hereditary cerebral small vessel disease is the loss of smooth muscle cells, which is an also well-recognized finding in sporadic cerebral small vessel disease. Since pericytes have similar character with the smooth muscle cells, the pericytes should be investigated in these disorders. In addition, the loss of smooth muscle cells may result in dysfunction of drainage of interstitial fluid from capillaries. The precise correlation between the loss of smooth muscle cells and white matter disease is still unknown. However, the function that is specific to cerebral small vessel may be associated with the pathogenesis of cerebral small vessel disease. (author)

  11. Caffeine induced changes in cerebral circulation

    International Nuclear Information System (INIS)

    While the caffeine induced cerebral vasoconstriction is well documented, the effects of oral ingestion of the drug in a dose range comparable to the quantities in which it is usually consumed and the intensity and duration of the associated reduction in cerebral circulation are unknown. Cerebral blood flow was measured via the 133Xenon inhalation technique before and thirty and ninety minutes after the oral administration of 250 mg of caffeine or a placebo, under double-blind conditions. Caffeine ingestion was found to be associated with significant reductions in cerebral perfusion thirty and ninety minutes later. The placebo group showed no differences between the three sets of cerebral blood flow values

  12. Contraceptives and cerebral thrombosis: a five-year national case-control study

    DEFF Research Database (Denmark)

    Lidegaard, Øjvind; Kreiner, Svend

    2002-01-01

    Oral contraceptives; Cerebral thrombosis; Thrombotic stroke; Transitory cerebral ischemic attack; Thrombosis......Oral contraceptives; Cerebral thrombosis; Thrombotic stroke; Transitory cerebral ischemic attack; Thrombosis...

  13. Early cerebral circulatory disturbance in patients suffering subarachnoid hemorrhage prior to the delayed cerebral vasospasm stage. Xenon computed tomography and perfusion computed tomography study

    International Nuclear Information System (INIS)

    Subarachnoid hemorrhage (SAH) causes dynamic changes in cerebral blood flow (CBF), and results in delayed ischemia due to vasospasm, and early perfusion deficits before delayed cerebral vasospasm (CVS). The present study examined the severity of cerebral circulatory disturbance during the early phase before delayed CVS and whether it can be used to predict patient outcome. A total of 94 patients with SAH underwent simultaneous xenon computed tomography (CT) and perfusion CT to evaluate cerebral circulation on Days 1-3. Cerebral blood flow (CBF) was measured using xenon CT and the mean transit time (MTT) using perfusion CT and calculated cerebral blood volume (CBV). Outcome was evaluated with the Glasgow Outcome Scale (good recovery [GR], moderate disability [MD], severe disability [SD], vegetative state [VS], or death [D]). Hunt and Hess (HH) grade II patients displayed significantly higher CBF and lower MTT than HH grade IV and V patients. HH grade III patients displayed significantly higher CBF and lower MTT than HH grade IV and V patients. Patients with favorable outcome (GR or MD) had significantly higher CBF and lower MTT than those with unfavorable outcome (SD, VS, or D). Discriminant analysis of these parameters could predict patient outcome with a probability of 74.5%. Higher HH grade on admission was associated with decreased CBF and CBV and prolonged MTT. CBF reduction and MTT prolongation before the onset of delayed CVS might influence the clinical outcome of SAH. These parameters are helpful for evaluating the severity of SAH and predicting the outcomes of SAH patients. (author)

  14. Bilateral posterior cerebral artery infarction

    OpenAIRE

    Ryan, Davinia; Murphy, Sinead M; Hennessey, Michael J

    2010-01-01

    We report the case of a 70-year-old man who presented with short-term memory impairment and a homonymous left inferior quadrantanopia secondary to simultaneous bilateral posterior cerebral artery (PCA) territory infarction. As in more than a quarter of cases of PCA

  15. MR imaging of cerebral palsy

    Energy Technology Data Exchange (ETDEWEB)

    Saginoya, Toshiyuki [Urasoe General Hospital, Okinawa (Japan); Yamaguchi, Keiichiro; Kuniyoshi, Kazuhide [and others

    1996-06-01

    We evaluated 35 patients with cerebral palsy on the basis of MR imaging findings in the brain. The types of palsy were spastic quadriplegia (n=11), spastic diplegia (n=9), spastic hemiplegia (n=2), double hemiplegia (n=1), athetosis (n=10) and mixed (n=2). Of all patients, 28 (80%) generated abnormal findings. In spastic quadriplegia, although eight cases revealed severe brain damage, two cases showed no abnormal findings in the brain. One of the three had cervical cord compression caused by atlanto-axial subluxation. In spastic diplegia, the findings were divided according to whether the patient was born at term or preterm. If the patient had been born prematurely, the findings showed periventricular leukomalacia and abnormally high intensity in the posterior limbs of the internal capsule on T2-weighted images. MR imaging in spastic hemiplegia revealed cerebral infarction. In the athetoid type, half of all cases showed either no abnormal findings or slight widening of the lateral ventricle. Three cases showed abnormal signals of the basal ganglia. The reason why athetoid-type palsy did not show severe abnormality is unknown. We believe that MR imaging is a useful diagnostic modality to detect damage in the brain in cerebral palsy and plays an important role in the differentiation of cerebral palsy from the spastic palsy disease. (author)

  16. Cerebral imaging revealing Alzheimer's disease

    International Nuclear Information System (INIS)

    Cerebral imaging is the only non-invasive means of examining the brain and is essential in studying Alzheimer's disease. As a tool for early diagnosis, evaluation and treatment monitoring, this technology is at the heart of the research being done to further improve its reliability and sensitivity. (authors)

  17. Cerebral Palsy and Neonatal Encephalopathy

    OpenAIRE

    J Gordon Millichap

    2005-01-01

    The type and severity of cerebral palsy (CP) and pattern of associated disability in children with or without preceding neonatal encephalopathy (NE) were compared in a population-based case-control study of patients followed for 6 years at the Children’s Hospital, Westmead, Sydney, Australia.

  18. Ocular defects in cerebral palsy

    OpenAIRE

    Katoch Sabita; Devi Anjana; Kulkarni Prajakta

    2007-01-01

    There is a high prevalence of ocular defects in children with developmental disabilities. This study evaluated visual disability in a group of 200 cerebral palsy (CP) patients and found that 68% of the children had significant visual morbidity. These findings emphasize the need for an early ocular examination in patients with CP.

  19. [Cerebral ischemia in young adults].

    Science.gov (United States)

    Berlit, P; Endemann, B; Vetter, P

    1991-08-01

    An overview is given over etiology and prognosis of cerebral ischemias until the age of 40. In a time period of 19 years, 168 patients were diagnosed with cerebral ischemia until the age of 40 (91 females, 77 males). The most frequent etiology is premature atherosclerosis in patients with vascular risk factors (up to 50%). Cardiogenic embolism is responsible for 1 to 34% of the cases: cardiac valve diseases and endocarditis being the most frequent sources. In 2 to 19% a vasculitis is diagnosed. While infectious arteritis is especially frequent in countries of the third world, immunovasculitides are common in Europe and the USA. Noninflammatory vasculopathies include spontaneous or traumatic dissection, fibromuscular dysplasia and vascular malformations. A migrainous stroke is especially frequent in female smokers with intake of oral contraceptives. During pregnancy both sinus thrombosis and arterial ischemia occur. Hematologic causes for ischemia are polycythemia, thrombocytosis and genetic diseases (sickle cell anemia, AT3-deficiency). Cerebral ischemia may occur in connection with the ingestion of ergot-derivates. The prognosis of cerebral ischemia in young adults is better than in older stroke-patients. PMID:1937340

  20. CT of cerebral hydatid disease

    International Nuclear Information System (INIS)

    Six cases of cerebral hydatid disease (CHD) were seen in Kuwait over a period of 8 years. The typical CT appearance of a large well-defined spherical nonenhanced unilocular cyst was seen in four cases. Two unusual but characteristic types of calcification were seen, one in each of the remaining two cases. (orig.)

  1. MR imaging of cerebral palsy

    International Nuclear Information System (INIS)

    We evaluated 35 patients with cerebral palsy on the basis of MR imaging findings in the brain. The types of palsy were spastic quadriplegia (n=11), spastic diplegia (n=9), spastic hemiplegia (n=2), double hemiplegia (n=1), athetosis (n=10) and mixed (n=2). Of all patients, 28 (80%) generated abnormal findings. In spastic quadriplegia, although eight cases revealed severe brain damage, two cases showed no abnormal findings in the brain. One of the three had cervical cord compression caused by atlanto-axial subluxation. In spastic diplegia, the findings were divided according to whether the patient was born at term or preterm. If the patient had been born prematurely, the findings showed periventricular leukomalacia and abnormally high intensity in the posterior limbs of the internal capsule on T2-weighted images. MR imaging in spastic hemiplegia revealed cerebral infarction. In the athetoid type, half of all cases showed either no abnormal findings or slight widening of the lateral ventricle. Three cases showed abnormal signals of the basal ganglia. The reason why athetoid-type palsy did not show severe abnormality is unknown. We believe that MR imaging is a useful diagnostic modality to detect damage in the brain in cerebral palsy and plays an important role in the differentiation of cerebral palsy from the spastic palsy disease. (author)

  2. Cerebral edema in drug addicts

    Directory of Open Access Journals (Sweden)

    Daruši Dragana J.

    2014-01-01

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

  3. Late cerebral ischaemia after subarachnoid haemorrhage

    DEFF Research Database (Denmark)

    Edvinsson, L; Povlsen, G K

    2011-01-01

    Late cerebral ischaemia after subarachnoid haemorrhage (SAH) carries high morbidity and mortality because of reduced cerebral blood flow (CBF) and subsequent cerebral ischaemia. This is associated with upregulation of contractile receptors in cerebral artery smooth muscles via the activation of...... intracellular signalling. In addition, delayed cerebral ischaemia after SAH is associated with inflammation and disruption of the blood-brain barrier (BBB). This article reviews recent evidence concerning the roles of vasoconstrictor receptor upregulation, inflammation and BBB breakdown in delayed cerebral...... ischaemia after SAH. In addition, recent studies investigating the role of various intracellular signalling pathways in these processes and the possibilities of targeting signalling components in SAH treatment are discussed. Studies using a rat SAH model have demonstrated that cerebral arteries increase...

  4. 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

    Full Text Available JUSTIFICATIVA E OBJETIVOS: A paralisia cerebral (PC é uma doença não progressiva decorrente de lesão no sistema nervoso central, levando a um comprometimento motor do paciente. O portador de PC freqüentemente é submetido a procedimentos cirúrgicos devido a doenças usuais e situações particulares decorrentes da paralisia cerebral. Foi objetivo deste artigo revisar aspectos da paralisia cerebral de interesse para o anestesiologista, permitindo um adequado manuseio pré, intra e pós-operatório neste tipo de paciente. CONTEÚDO: O artigo aborda aspectos da paralisia cerebral como etiologia, classificação, fatores de risco, fisiopatologia, quadro clínico, diagnóstico, terapêuticas utilizadas bem como avaliação pré-operatória, medicação pré-anestésica, manuseio intra e pós-operatório, analgesia pós-operatória e dor crônica. CONCLUSÕES: O anestesiologista desempenha um papel importante na diminuição da morbidade e mortalidade anestésico-cirúrgica em pacientes portadores de paralisia cerebral. O conhecimento da fisiopatologia dos diferentes tipos de paralisia cerebral bem como das doenças associadas e suas terapêuticas é imprescindível, pois permite ao anestesiologista antecipar e prevenir complicações intra e pós-operatórias neste tipo de paciente.JUSTIFICATIVA Y OBJETIVOS: La parálisis cerebral (PC es una enfermedad no progresiva consecuente de una lesión en el sistema nervioso central, llevando a un comprometimiento motor del paciente. El portador de PC, frecuentemente es sometido a procedimientos quirúrgicos debido a enfermedades usuales y situaciones particulares consecuentes de la parálisis cerebral. El objetivo de este artículo, fue revisar aspectos de la parálisis cerebral de interés para el anestesista, permitiendo un adecuado manoseo pre, intra y posoperatorio en este tipo de paciente. CONTENIDO: El artículo aborda aspectos de la parálisis cerebral como etiología, clasificación, factores de

  5. Changes in the profile of NO synthases affect coronary blood flow autoregulation and myocardial contractile activity during restraint stress in rats.

    Science.gov (United States)

    Solodkov, A P; Lazuko, S S; Knyazev, E N; Nechaev, I N; Krainova, N A

    2014-12-01

    The efficiency of autoregulation of the coronary blood flow and contractile activity of the myocardium in the presence of inhibitors of constitutive and inducible NO synthases was studied in rats exposed to 6-h restraint stress. Intracoronary administration of S-methylisothiourea (10 μmol/liter), but not L-NAME (60 μmol/liter) fully prevented post-stress increase in the volume coronary blood flow rate, intensity of heart perfusion, and reduction of ventricular developed pressure at all levels of perfusion pressure. Real-time PCR showed 6-fold increased expression of inducible NO-synthase mRNA in the heart tissue against the background of unchanged expression of neuronal and endothelial NO synthases and 2-3-fold elevated content of transcripts of stress-inducible genes Hspa1a and Hspbp1. It was shown that the hypotension of coronary vessels and reduced contractile function of the myocardium are related to NO production by inducible NO synthase in endotheliocytes of coronary vessels and cardiomyocytes. PMID:25430647

  6. Digital subtraction angiography in cerebral infarction

    International Nuclear Information System (INIS)

    The usefulness and radiographic findings of the angiography in cerebral infarction are well known. We attempted to evaluate the angiographic causes, findings, and the usefulness of DSA in cerebral infarction. The authors reviewed retrospectively DSA images of 51 patients who were diagnosed as having cerebral infarction by brain CT and/or MRI and clinical settings. DSA was performed in all 51 patients, and in 3 patients, conventional angiogram was also done. Both carotid DSA images were obtained in AP, lateral, oblique projections, and one or both vertebral DSA images in AP and lateral. The authors reviewed the patient's charts for symptoms, operative findings and final diagnosis, and analysed DSA findings of cerebral atherosclerosis with focus on 6 major cerebral arteries. Among the 51 patients of cerebral infarction 43 patients (84.3%) had cerebral atherosclerosis, 1 dissecting aneurysm, 1 moyamoya disease and 6 negative in angiogram. DSA findings of cerebral atherosclerosis were multiple narrowing in 42 patients (97.7%), tortuosity in 22 (51.2%), dilatation in 14, occlusion in 12, avascular region in 8, collaterals in 7, ulcer in 6, and delayed washout of contrast media in 3. In cerebral atherosclerosis, internal carotid artery was involved in 37 patients (86.0%), middle cerebral artery in 29 (67.4%) posterior cerebral artery in 28, anterior cerebral artery in 26, vertebral artery in 22, and basilar artery in 15. Intracranial involvement of cerebral atherosclerosis (64.9%) was more common than extracranial involvement (16.2%). In cerebral infarction MRA may be the screening test, but for more precise evaluation of vascular abnormality and its extent, DSA should be considered

  7. The effects of propofol on cerebral perfusion MRI in children

    Energy Technology Data Exchange (ETDEWEB)

    Harreld, Julie H.; Helton, Kathleen J.; Reddick, Wilburn E.; Glass, John O.; Sansgiri, Rakhee; Ji, Qing; Patay, Zoltan [St. Jude Children' s Research Hospital, Department of Radiological Sciences, Memphis, TN (United States); Kaddoum, Roland N.; Parish, Mary Edna [St. Jude Children' s Research Hospital, Department of Anesthesiology, Memphis, TN (United States); Li, Yimei; Feng, Tianshu [St. Jude Children' s Research Hospital, Department of Biostatistics, Memphis, TN (United States); Gajjar, Amar [St. Jude Children' s Research Hospital, Department of Oncology, Memphis, TN (United States)

    2013-08-15

    The effects of anesthesia are infrequently considered when interpreting pediatric perfusion magnetic resonance imaging (MRI). The objectives of this study were to test for measurable differences in MR measures of cerebral blood flow (CBF) and cerebral blood volume (CBV) between non-sedated and propofol-sedated children, and to identify influential factors. Supratentorial cortical CBF and CBV measured by dynamic susceptibility contrast perfusion MRI in 37 children (1.8-18 years) treated for infratentorial brain tumors receiving propofol (IV, n = 19) or no sedation (NS, n = 18) were compared between groups and correlated with age, hematocrit (Hct), end-tidal CO{sub 2} (ETCO{sub 2}), dose, weight, and history of radiation therapy (RT). The model most predictive of CBF and CBV was identified by multiple linear regression. Anterior cerebral artery (ACA) and middle cerebral artery (MCA) territory CBF were significantly lower, and MCA territory CBV greater (p = 0.03), in IV than NS patients (p = 0.01, 0.04). The usual trend of decreasing CBF with age was reversed with propofol in ACA and MCA territories (r = 0.53, r = 0.47; p < 0.05). ACA and MCA CBF (r = 0.59, 0.49; p < 0.05) and CBV in ACA, MCA, and posterior cerebral artery territories (r = 0.73, 0.80, 0.52; p < 0.05) increased with weight in propofol-sedated children, with no significant additional influence from age, ETCO{sub 2}, hematocrit, or RT. In propofol-sedated children, usual age-related decreases in CBF were reversed, and increases in CBF and CBV were weight-dependent, not previously described. Weight-dependent increases in propofol clearance may diminish suppression of CBF and CBV. Prospective study is required to establish anesthetic-specific models of CBF and CBV in children. (orig.)

  8. Effects of hyperglycemia on the cerebrovascular response to rhythmic handgrip exercise

    NARCIS (Netherlands)

    Y.S. Kim; R. Krogh-Madsen; P. Rasmussen; P. Plomgaard; S. Ogoh; N.H. Secher; J.J. van Lieshout

    2007-01-01

    Dynamic cerebral autoregulation (CA) is challenged by exercise and may become less effective when exercise is exhaustive. Exercise may increase arterial glucose concentration, and we evaluated whether the cerebrovascular response to exercise is affected by hyperglycemia. The effects of a hyperinsuli

  9. Regional cerebral blood flow after hemorrhagic hypotension in the preterm, near-term, and newborn lamb.

    Science.gov (United States)

    Szymonowicz, W; Walker, A M; Yu, V Y; Stewart, M L; Cannata, J; Cussen, L

    1990-10-01

    Developmental changes in regional cerebral blood flow (CBF) responses to hemorrhagic hypotension during normoxia and normocapnia were determined using radioactively labeled microspheres to measure flow to the cortex, brainstem, cerebellum, white matter, caudate nucleus, and choroid plexus in three groups of chronically catheterized lambs: 90- to 100-d preterm fetal lambs (n = 9); 125- to 136-d near-term fetal lambs (n = 9); and newborn lambs 5- to 35-d-old (n = 8). Heart rate, central venous pressure, and arterial blood pressure were monitored continuously and arterial blood gas tensions, pH, Hb, and oxygen saturation together with regional CBF were measured periodically. Hemorrhagic hypotension produced a mean decrease in arterial blood pressure of 27 +/- 4, 23 +/- 2, and 41 +/- 4% in the three groups, respectively, whereas reinfusion of the lamb's blood resulted in a return to control blood pressure within 3% in all three groups. In the pre-term fetal lamb, CBF decreased significantly in all regions during hypotension. In the near-term fetal lamb, only blood flow to the cortex decreased significantly during hypotension. In the newborn lamb, only the choroid plexus demonstrated a significant decrease in blood flow during hypotension. The lower limit of regional CBF autoregulation was identical to the resting mean arterial pressure in fetal life but significantly lower in newborn lambs. These experiments demonstrate for the first time that vulnerability to hypotension decreases with increasing maturity and that the brainstem, the phylogenetically oldest region of the brain, is the least vulnerable to the effects of hypotension at any age in the lamb model. PMID:2235134

  10. Cerebral aterial spasm. I. Adrenergic mechanism in experimental cerebral vasospasm.

    Directory of Open Access Journals (Sweden)

    Morooka,Hiroshi

    1978-04-01

    Full Text Available This study demonstrates that an adrenergic mechanism plays an important role in producing the delayed cerebral vasospasm which follows subarachnoid hemorrhage. Results were as follows: 1. Experimental subarachnoid hemorrhage (SAH was produced by injection of fresh arterial blood into the cisterna magna in cats. The cerebral vasospasm was shown angiographically to be biphasic in nature: immediate constriction lasting 1 h and marked prolonged spasm occurring between the 3rd and 5th day after SAH. The amount of noradrenaline (NA and dopamine-beta-hydroxylase (DBH activity decreased over a period of 24 h both within the wall of the basilar artery and in the locus ceruleus and then gradually increased, reaching a maximum on the 3rd day after SAH. 2. Topical application of spasmogenic substances (NA and blood produced a marked constriction of the hypersensitive basilar artery on the 3rd day after SAH. 3. 6-Hydroxydopamine (6-OHDA injection into the cisterna magna produced prolonged vasocilatation. The dilated vessel responded with mild transient constriction after the topical application of NA or fresh blood. DBH activity and NA concentration in the vessels, locus ceruleus and medial hypothalamus decreased markedly on the 3rd day after the cisternal injection of 6-OHDA. 4. Various spasmogenic substances (i.e. serotonin, NA, prostaglandins and methemoglobin were measured in a mixture of equal volume of CSF and blood in cats. ONly the serotonin in the mixed fluid produced vasoconstriction. Spasmogenic substances decreased markedly in the mixed fluid incubated for 3 days at 37 degrees C, and none of these substances apart from methemoglobin was present in a concentration sufficient to produce constriction of vessels. 5. These results suggest that early spasm is induced by serotonin around the arteries of the cranial base, and delayed spasm might be caused by hyperreaction of cerebral vessels to spasmogenic substances such as methemoglobin, during the

  11. Middle cerebral artery blood velocity and plasma catecholamines during exercise

    DEFF Research Database (Denmark)

    Pott, F; Jensen, K; Hansen, H;

    1996-01-01

    . Vmean increased by 31 +/- 3% and 48 +/- 4%, respectively, and this was significantly higher compared to handgrip (P < 0.05). During maximal cycling, plasma adrenaline increased from 0.21 +/- 0.04 nmol L-1 at rest to 4.18 +/- 1.46 nmol L-1, and noradrenaline increased from 0.79 +/- 0.08 to 12.70 +/- 1......During dynamic exercise, mean blood velocity (Vmean) in the middle cerebral artery (MCA) demonstrates a graded increase to work rate and reflects regional cerebral blood flow. At a high work rate, however, vasoactive levels of plasma catecholamines could mediate vasoconstriction of the MCA and...... thereby elevate Vmean at a given volume flow. To evaluate transcranial Doppler-determined Vmean at high plasma catecholamine levels, seven elite cyclists performed a maximal performance test on a bicycle ergometer. Results were compared with those elicited during five incremental exercise bouts and during...

  12. A model for cerebral ischaemia from gaseous emboli

    CERN Document Server

    Hague, J P; Chung, E M L

    2012-01-01

    The effects of bubbles on the cerebral bloodflow are difficult to quantify. We present a model to calculate how cerebral ischaemia is caused by deformable gaseous emboli. The model takes into account realistic adhesion forces, fluid dynamical considerations, a realistic parameterisaton for the rate of bubble dissolution and the effects of buoyancy. We find that neglecting deformability of bubbles leads to a vast overestimation of ischaemia. The inclusion of buoyancy effects reduces the proportion of the vasculature that becomes compromised, but increases blockage times, thus lowering the risk of transient ischaemia but increasing the potential for focal injury. We also investigate the number and size of bubbles in a sudden shower of emboli that leads to persistent ischaemia capable of neuronal injury. Finally we investigate mitigation techniques such as insufflation of the operative area with CO$_2$ and alterations in arterial pressure.

  13. What's new in cerebral palsy.

    Science.gov (United States)

    JONES, M H

    1953-11-01

    Among new researches bearing on cerebral palsy are the growth of brain cells in tissue cultures for experimentation; the use of polysaccharides to prevent the formation of a glial barrier to nerve growth after injury; observation of changes in reactions of neurons at various stages of development; the finding of hypernatremia and hyperchloremia in lesions of the frontal lobe and the thalamus; stimulation of cerebral blood flow by injection of sodium bicarbonate and retardation with ammonium chloride; and studies of serial sections of brains of palsied children who died. Study of development in the early months of life has made possible the detection of significant abnormalities in behavior early in life. Loss of hearing may be tested in very young children by measuring minute variations in electrical resistance of the skin upon auditory stimulation of the sympathetic nervous system. Conditions which have been described as having been confused with cerebral palsy are dislocation of a cervical vertebra, hereditary spastic paraplegia, transverse myelopathy, injury to the spinal cord or cauda equina by anomalous growths of the spine, and also encephalitis and meningitis. Sedation has proved a valuable adjunct to electroencephalographic study of cerebral palsy. Better criteria for abnormality in the young child should be determined and the application of them more clearly standardized. Simple exercises are useful for early training of palsied children to stimulate development. "Crossed laterality"-the dominant eye being contralateral to the preferred hand-has been counteracted by special training with great success in eliminating emotional and behavior problems and accelerating development.Recent studies indicate that only 50 per cent of cerebral palsy patients have normal or better intelligence. Subluxation of the hip joint, a common deformity associated with cerebral palsy, can sometimes be corrected by operation if detected at an early stage. Radical ablation of

  14. Evaluation of cerebral hemodynamics by 123I-IMP in cerebral AVMs before and after operation by using SPECT

    International Nuclear Information System (INIS)

    To evaluate cerebral hemodynamics by N-isopropyl-p-[123I]-iodoamphetamine (123I-IMP) preoperative and postoperative (after 1 day, and after 7-10 days) regional cerebral blood flow scan, 6 arteriovenous malformations (AVMs) which performed total removal operations were studied by using a ring type SPECT 'HEADTOME'. We performed the dynamic scan just after the intravenous injection of 222 MBq (6 mCi) of 123I-IMP, then the static scan 20 minutes after the intravenous injection. In preoperative dynamic scans of all cases, only the first frame image showed the increased activity on the nidus probably because of the blood pool. Preoperative static scans of all cases showed the remarkable decreased activity on the nidus, and decreased activity surrounding the nidus probably because of the peripheral steal phenomenon. In postoperative scan of the next day, 4 out of 6 cases showed the transient decreased peripheral steal, particularly 2 out of those 4 cases showed the transient hyperperfusion probably because of the normal perfusion pressure break-through (NPPB). And, 2 out of 6 cases showed transient peripheral low perfusion on much larger area than those of the preoperative scans probably because of the focal brain damages and edemas. We conclude that 123I-IMP SPECT on AVM is very useful to decide the indication of the removal operation, and to estimate the postoperative risk, and to evaluate the preoperative and postoperative cerebral hemodynamic changes in the peripheral area of AVM. (author)

  15. CEREBRAL PALSY. PRENTICE-HALL FOUNDATIONS OF SPEECH PATHOLOGY SERIES.

    Science.gov (United States)

    CHANCE, BURTON, JR.; MCDONALD, EUGENE T.

    THIS INTRODUCTORY TEXT ON CEREBRAL PALSY IS DIVIDED INTO TWO SECTIONS. THE FIRST SECTION OF THE BOOK CONTAINS INFORMATION ABOUT UNDERSTANDING THE MEANING OF CEREBRAL PALSY, PROGRAMS FOR THOSE WITH CEREBRAL PALSY, THE NEUROLOGICAL BASES, ETIOLOGY, AND DIAGNOSIS, AND THE CLASSIFICATION OF CEREBRAL PALSY. PROBLEMS OFTEN ASSOCIATED WITH CEREBRAL PALSY…

  16. Time evolution and hemodynamics of cerebral aneurysms

    Science.gov (United States)

    Sforza, Daniel M.; Putman, Christopher; Tateshima, Satoshi; Viñuela, Fernando; Cebral, Juan

    2011-03-01

    Cerebral aneurysm rupture is a leading cause of hemorrhagic strokes. Because they are being more frequently diagnosed before rupture and the prognosis of subarachnoid hemorrhage is poor, clinicians are often required to judge which aneurysms are prone to progression and rupture. Unfortunately, the processes of aneurysm initiation, growth and rupture are not well understood. Multiple factors associated to these processes have been identified. Our goal is to investigate two of them, arterial hemodynamics (using computational fluid dynamics) and the peri-aneurysmal environment, by studying a group of growing cerebral aneurysms that are followed longitudinally in time. Six patients with unruptured untreated brain aneurysms which exhibited growth during the observation period were selected for the study. Vascular models of each aneurysm at each observation time were constructed from the corresponding computed tomography angiography (CTA) images. Subsequently, models were aligned, and geometrical differences quantified. Blood flow was modeled with the 3D unsteady incompressible Navier-Stokes equation for a Newtonian fluid, and wall shear stress distribution and flow patterns were calculated and visualized. Analysis of the simulations and changes in geometry revealed asymmetric growth patterns and suggests that areas subject to vigorous flows, i.e. relative high wall shear stress and concentrated streamlines patterns; correspond to regions of aneurysm growth. Furthermore, in some cases the geometrical evolution of aneurysms is clearly affected by contacts with bone structures and calcifications in the wall, and as a consequence the hemodynamics is greatly modified. Thus, in these cases the peri-aneurysmal environment must be considered when analyzing aneurysm evolution.

  17. A new imaging method of cerebral blood flow by 133Xe inhalation: application for studying naloxone in cerebral ischemia

    International Nuclear Information System (INIS)

    A calculation and dynamic imaging method of cerebral blood flow (CBF) based on gamma camera images after 133-Xenon inhalation is proposed. The method consists in the deconvolution by approximation of the time sequence of brain scans by the values for the arterial concentration. Computation is limited to the first 2 minutes of wash-out. Results are compared to those obtained with the Obrist method and with Fourier-transform deconvolution. In 28 patients data obtained with the 3 methods were found to show good agreement (r=0.93). The method was used to study the effects of low-dose Naloxone on cerebral blood flow in ischemic patients and evidence of some regional hemodynamic action was obtained. But these changes apparently do not correspond with the definite, though transient clinical improvement seen in 5 patients. (Author)

  18. Animal models of cerebral ischemia

    Science.gov (United States)

    Khodanovich, M. Yu.; Kisel, A. A.

    2015-11-01

    Cerebral ischemia remains one of the most frequent causes of death and disability worldwide. Animal models are necessary to understand complex molecular mechanisms of brain damage as well as for the development of new therapies for stroke. This review considers a certain range of animal models of cerebral ischemia, including several types of focal and global ischemia. Since animal models vary in specificity for the human disease which they reproduce, the complexity of surgery, infarct size, reliability of reproduction for statistical analysis, and adequate models need to be chosen according to the aim of a study. The reproduction of a particular animal model needs to be evaluated using appropriate tools, including the behavioral assessment of injury and non-invasive and post-mortem control of brain damage. These problems also have been summarized in the review.

  19. Chinese semantic processing cerebral areas

    Institute of Scientific and Technical Information of China (English)

    SHAN Baoci; ZHANG Wutian; MA Lin; LI Dejun; CAO Bingli; TANG Yiyuan; WU Yigen; TANG Xiaowei

    2003-01-01

    This study has identified the active cerebral areas of normal Chinese that are associated with Chinese semantic processing using functional brain imaging. According to the traditional cognitive theory, semantic processing is not particularly associated with or affected by input modality. The functional brain imaging experiments were conducted to identify the common active areas of two modalities when subjects perform Chinese semantic tasks through reading and listening respectively. The result has shown that the common active areas include left inferior frontal gyrus (BA 44/45), left posterior inferior temporal gyrus (BA37); the joint area of inferior parietal lobules (BA40) and superior temporal gyrus, the ventral occipital areas and cerebella of both hemispheres. It gives important clue to further discerning the roles of different cerebral areas in Chinese semantic processing.

  20. Cerebral calcifications and schizophreniform disorder

    Directory of Open Access Journals (Sweden)

    Leonardo Fernandez Meyer

    2013-01-01

    Full Text Available OBJECTIVES: Discuss pathophysiological aspects of cerebral calcifications (CC and highlight its importance related to the occurrence of neuropsychiatric syndromes. METHOD: Single case report. RESULT: Man 52 years old, 20 years after going through a total thyroidectomy, starts showing behavioral disturbance (psychotic syndrome. He was diagnosed as schizophrenic (paranoid subtype and submitted to outpatient psychiatric treatment. During a psychiatric admission to evaluate his progressive cognitive and motor deterioration, we identified a dementia syndrome and extensive cerebral calcifications, derived from iatrogenic hypoparathyroidism. CONCLUSION: The calcium and phosphorus disturbances, including hypoparathyroidism, are common causes of CC. Its symptoms can imitate psychiatric disorders and produce serious and permanent cognitive sequelae. The exclusion of organicity is mandatory in any psychiatric investigative diagnosis in order to avoid unfavorable outcomes, such as in the present case report.

  1. Bilateral posterior cerebral artery infarction.

    Science.gov (United States)

    Ryan, Davinia; Murphy, Sinead M; Hennessey, Michael J

    2010-01-01

    We report the case of a 70-year-old man who presented with short-term memory impairment and a homonymous left inferior quadrantanopia secondary to simultaneous bilateral posterior cerebral artery (PCA) territory infarction. As in more than a quarter of cases of PCA infarction, no aetiological cause was identified. Unlike the transient nature of symptoms in some cases following unilateral infarction, his deficits persisted on 2-month follow-up. PMID:22798298

  2. Clinical studies on cerebral infarction

    International Nuclear Information System (INIS)

    Hemorrhagic infarction (HI) is termed as the infarction in which a large part of the necrotic tissue is stippled with small hemorrhage. The pathogenetic mechanism of this disease still remains controversial. Cerebral infarction has long been divided into two subtypes-thrombosis and embolism-according to the pathogenetic mechanisms. Clinical studies were carried out in 31 cases of HI with cerebral thrombosis. CT findings of these cases were classified into five groups according to both size of low density area which indicates regions of infarction and distribution of arterial supply. The low density area of Type I-Type III were observed in the area of the middle cerebral artery. That of Type IV was observed in the area of the internal capsule and basal ganglia. That of Type V was observed in the area of the posterior cerebral artery. CT reveals two patterns of HI -pattern A and pattern B-. The CT finding of pattern A is appearance of high density area in the low density area. The CT finding of pattern B is appearance of iso density area in the low density area. rCBF was measured by 133Xe inhalation technique in 21 patients with CT type I, II and III. Thereafter, with regard to the various findings in CT, the clinical findings and CBF findings, a comparative study was carried out on these ten groups. From the results of present studies, it is concluded that sequential changes of CBF in cases with pattern A are different from those with pattern B, and that CBF measurement does not permit an estimation of a patient's chance for functionary recovery after a stroke in acute and subacute stage but permits estimation of functional outcome in chronic stage. (J.P.N.)

  3. Cerebral palsy and neonatal encephalopathy.

    OpenAIRE

    Gaffney, G; Flavell, V; Johnson, A; Squier, M.; Sellers, S

    1994-01-01

    A retrospective cohort study was carried out to test the hypothesis that children born at term with cerebral palsy with signs of neurological dysfunction preceded by depression at birth (termed neonatal encephalopathy) differ from those without such signs in the frequency of antenatal and perinatal factors, and in the severity and characteristics of their impairment and disability. The study was carried out in the area covered by Oxford Regional Health Authority. Antenatal, intrapartum, neona...

  4. Visual disorders in cerebral palsy

    OpenAIRE

    Govind Amita; Lamba P

    1988-01-01

    Seventy children with cere-bral palsy were examined for aetiological factors responsible, type of disorder and ocular abnormalities. The overall inci-dence of ocular abnormalities was 68.69%, the highest frequency being of squint (35.7%). Other anomalies detected inclu-ded refractive errors (28.5%), optic atrophy (10%) and coloboma (2.9%). Most children were spastic quadriplegics with asphyxia as the major aetiological factor. The study created an awareness ...

  5. Primary cerebral lymphoma: radiological findings

    International Nuclear Information System (INIS)

    We present four cases of primary cerebral lymphoma in non-immunodepressed adult patients. All cases were dsemonstrated with pathological study. CAT study showed solitary or multiple isodense lesions, which incorporated avidly and homoneneously the contrast. Arteriography performed in three patients and magnetic resonance, performed in one did not help for diagnosis. We also review the radiological findings obtained with different imaging methods, and suggest the criteria which could be useful for early diagnosis (Author)

  6. Baclofen in Spastic Cerebral Palsy

    OpenAIRE

    J Akhundian

    2002-01-01

    To evaluate the effect of oral baclofen in spastic cerebral palsy (cp), we studied 40 children with different clinical types of spastic cp. Half of these children served as control group and the others received oral baclofen. All of them were treated with physiotherapy under equal conditions for 6 weeks. We used two methods, modified Ashworth scale and range of motion for evaluation. At the end of therapy we found a significant improvement in the baclofen group compared to control group. As a...

  7. Cerebral palsy in preterm infants

    OpenAIRE

    Demeši-Drljan Čila; Mikov Aleksandra; Filipović Karmela; Tomašević-Todorović Snežana; Knežević Aleksandar; Krasnik Rastislava

    2016-01-01

    Background/Aim. Cerebral palsy (CP) is one of the leading causes of neurological impairment in childhood. Preterm birth is a significant risk factor in the occurrence of CP. Clinical outcomes may include impairment of gross motor function and intellectual abilities, visual impairment and epilepsy. The aim of this study was to examine the relationships among gestational age, type of CP, functional ability and associated conditions. Methods. The sample size w...

  8. Cerebral Palsy: A Dental Update

    OpenAIRE

    Sehrawat, Nidhi; Marwaha, Mohita; Bansal, Kalpana; Chopra, Radhika

    2014-01-01

    ABSTRACT Special and medically compromised patients present a unique population that challenges the dentist’s skill and knowledge. Providing oral care to people with cerebral palsy (CP) requires adaptation of the skills we use everyday. In fact, most people with mild or moderate forms of CP can be treated successfully in the general practice setting. This article is to review various dental considerations and management of a CP patient. How to cite this article: Sehrawat N, Marwaha M, Bansal ...

  9. Acute hypoxia increases the cerebral metabolic rate

    DEFF Research Database (Denmark)

    Vestergaard, Mark Bitsch; Lindberg, Ulrich; Aachmann-Andersen, Niels Jacob;

    2016-01-01

    imaging techniques were used to measure global cerebral blood flow and the venous oxygen saturation in the sagittal sinus. Global cerebral metabolic rate of oxygen was quantified from cerebral blood flow and arteriovenous oxygen saturation difference. Concentrations of lactate, glutamate, N......-acetylaspartate, creatine and phosphocreatine were measured in the visual cortex by magnetic resonance spectroscopy. Twenty-three young healthy males were scanned for 60 min during normoxia, followed by 40 min of breathing hypoxic air. Inhalation of hypoxic air resulted in an increase in cerebral blood flow of 15.5% (p = 0.......058), and an increase in cerebral metabolic rate of oxygen of 8.5% (p = 0.035). Cerebral lactate concentration increased by 180.3% ([Formula: see text]), glutamate increased by 4.7% ([Formula: see text]) and creatine and phosphocreatine decreased by 15.2% (p[Formula: see text]). The N-acetylaspartate concentration...

  10. Behcet's disease with cerebral vasculitis

    International Nuclear Information System (INIS)

    The case presented illustrates the diagnostic dilemma off neurological involvement in Behcet's disease and other inflammatory diseases. 'Psychiatric' symptoms were present for 2 years without abnormalities on SPECT or MRI and without CSF pleocytosis. Even at the time of fitting, no CSF abnormalities were observed. The preceding psychiatric presentations may have been due to cerebral vasculitis that was exacerbated by withdrawal of steroids. Magnetic resonance imaging is currently the most sensitive imaging modality. Lesions are usually in the brainstem, cerebellum, basal ganglia region or periventricular white matter, and the pons and the mesencephalon are commonly affected. In our patient there was no diencephalic or brainstem involvement. The inflammatory process can appear as a very large lesion, with gadolinium enhancement and significant mass effect, as in our patient. Brain magnetic resonance imaging. Postgadolinium-diethylenetriamine pentaacetic acid, axial image shows two large lesions in the right frontal lobe, with the larger, posterior lesion demonstrating vivid ring enhancement. A central nodule is isodense, with the cerebral white matter within the larger lesion. Surrounding low T1 signal involves the hemispheric white matter without cortical extension and is consistent with vasogenic oedema. Minor mass effect is demonstrated with bowing of the anterior falx cerebri to the left. Biopsy shows prominent fibrinoid necrosis in small calibre postcapillary venules and cerebral white matter. There are surrounding acute and chronic inflammatory cells and nuclear debris, consistent with vasculitis

  11. MR findings of cerebral palsy

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-11-15

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

  12. MR findings of cerebral palsy

    International Nuclear Information System (INIS)

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

  13. Determination of NSE and GST Levels Before and After Treatment in Patients with Acute Cerebral Infarction and Its Clinical Significance

    International Nuclear Information System (INIS)

    To explore the changes of NSE and GST levels before and after treatment in patient with acute cerebral infarction and its clinical significance, the plasma NSE levels and serum GST levels in 64 patients with acute cerebral infarction and in 44 health controls were determined by RIA and EIA respectively. The results showed that there was significantly difference in the levels of NSE and GST between two groups,as well as before and after treatment. The determination of NSE and GST levels might be helpful in the diagnosis of patient with acute cerebral infarction and to assess the therapeutic efficacy dynamically. (authors)

  14. Estrogen intervention in microvascular morphology and choline acetyltransferase expression in rat hippocampal neurons in chronic cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    Zhenjun Yang; Hongwei Yan; Guomin Zhang; Zhihong Chen; Jingfeng Xue

    2011-01-01

    We observed dynamic changes in microvessels and a protective effect of estrogen on chronic cerebral ischemia ovariectomized rat models established through permanent occlusion of bilateral carotid arteries at 7, 14 and 21 days. The results revealed that estrogen improved microvasculature in the hippocampus of chronic cerebral ischemic rats, upregulated Bcl-2 protein expression, downregulated Bax protein expression, increased choline acetyltransferase expression in hippocampal cholinergic neurons, and suppressed hippocampal neuronal apoptosis. These findings indicate that estrogen can protect hippocampal neurons in rats with chronic cerebral ischemia.

  15. Parental age, genetic mutation, and cerebral palsy.

    OpenAIRE

    Fletcher, N A; Foley, J

    1993-01-01

    Parental age and birth order were studied in 251 patients with cerebral palsy. No parental age or birth order effects were observed in spastic quadriplegia or diplegia, but a paternal age effect was detected in those with athetoid/dystonic cerebral palsy and congenital hemiplegia. These observations indicate that some cases of athetoid/dystonic or hemiplegic cerebral palsy might arise by fresh dominant genetic mutation.

  16. Cerebral palsy in very low birthweight infants.

    OpenAIRE

    Cooke, R W

    1990-01-01

    Eighty one very low birthweight survivors with cerebral palsy were matched with controls by sex, gestational age, and place of birth. Using discriminant analysis, the perinatal profiles for infants with cerebral palsy and their controls were shown to differ significantly. When infants with various types of cerebral palsy were analysed with their controls the discriminating variables differed. Diplegic infants could be differentiated from controls on antenatal variables alone, but significant ...

  17. Evaluation measures for children with cerebral palsy

    OpenAIRE

    Sršen, Katja Groleger

    2013-01-01

    Abstract. Cerebral palsy is a well-recognized neurodevelopmental condition. The most recentdefinition describes cerebral palsy as a group of disorders of movement andposture, causing activity limitation. An important step in the process of(re)habilitation is evaluation of functional abilities of an individual. To beas accurate as possible in the evaluation of functioning, proper measurementinstruments have to be used. There are many different measurement tools forchildren with cerebral palsy,...

  18. Dental characteristics of children with cerebral palsy

    OpenAIRE

    Stevanović Radoje; Jovičić Olivera

    2004-01-01

    Cerebral palsy is one of the commonest children's physical handicaps with frequency of 1.5-3/1000. Beside many other disturbances, these children may have serious disorders caused by dental diseases. Concerning this fact, the objective of our study was to examine children with cerebral palsy in our country and determine condition of dental health and suggest adequate protective measures. A total of 116 children, 3-18 years old, with cerebral palsy were examined and the results were compared t...

  19. Epilepsy in children with cerebral palsy

    OpenAIRE

    J Akhundian

    2013-01-01

    Epilepsy occurs in 15-60% of children with cerebral palsy (CP). However, its clinical course is not well defined. This retrospective study reviews the prevalence, nature and prognosis of epilepsy in cerebral palsy. 53 of 133 children with cerebral palsy seen in the neuropediatric clinic in Mashhad emam Reza hospital between 1999 and 2001 had epilepsy. A control group of 70 epileptic children with normal neurodevelopment status was seen during the same period. Epilepsy most commonly affected p...

  20. Epilepsy in children with cerebral palsy

    OpenAIRE

    Bruck Isac; Antoniuk Sérgio Antônio; Spessatto Adriane; Bem Ricardo Schmitt de; Hausberger Romeu; Pacheco Carlos Gustavo

    2001-01-01

    OBJECTIVE: To describe the prevalence and characteristics of epilepsy in patients with cerebral palsy in a tertiary center. METHODS: a total of 100 consecutive patients with cerebral palsy were retrospectively studied. Criteria for inclusion were follow-up period for at least 2 years. Types and incidence of epilepsy were correlated with the different forms of cerebral palsy. Other factors associated with epilepsy such as age of first seizure, neonatal seizures and family history of epilepsy w...

  1. 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...... 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....

  2. Assessment of the hand in cerebral palsy

    OpenAIRE

    Praveen Bhardwaj; S Raja Sabapathy

    2011-01-01

    Cerebral palsy is the musculoskeletal manifestation of a nonprogressive central nervous system lesion that usually occurs due to a perinatal insult to the brain. Though the cerebral insult is static the musculoskeletal pathology is progressive. Some patients with cerebral palsy whose hands are affected can be made better by surgery. The surgical procedures as such are not very technically demanding but the assessment, decision-making, and selecting the procedures for the given patient make th...

  3. Cerebral Palsy. Fact Sheet = La Paralisis Cerebral. Hojas Informativas Sobre Discapacidades.

    Science.gov (United States)

    National Information Center for Children and Youth with Disabilities, Washington, DC.

    This fact sheet on cerebral palsy is written in both English and Spanish. First, it provides a definition of cerebral palsy and considers various causes (e.g., an insufficient amount of oxygen reaching the fetal or newborn brain). The fact sheet then offers incidence figures and explains characteristics of the three main types of cerebral palsy:…

  4. A study on the pathogenesis of human cerebral malaria and cerebral babesiosis

    Directory of Open Access Journals (Sweden)

    Masamichi Aikawa

    1992-01-01

    Full Text Available Cerebral complications are important, but poorly understood pathological features of infections caused by some species of Plasmodium and Babesia. Patients dying from P. falciparum were classified as cerebral or non-cerebral cases according to the cerebral malaria coma scale. Light microscopy revealed that cerebral microvessels of cerebral malaria patients were field with a mixture of parazited and unparazited erythrocytes, with 94% of the vessels showing parasitized red blood cell (PRBC sequestration. Some degree of PRBC sequestration was also found in non-cerebral malaria patients, but the percentage of microvessls with sequestered PRBC was only 13% Electron microscopy demonstrated knobs on the membrane of PRBC that formed focal junctions with the capillary endothelium. A number of host cell molecules such as CD36, thrombospondim (TSP and intracellular adhesion molecule I (ICAM-1 may function as endothelial cell surfacereports for P. falciparum-infected erythrocytes. Affinity labeling of CD36 and TSP to the PRBC surface showed these molecules specifically bind to the knobs. Babesia bovis infected erythrocytes procedure projections of the erythrocyte membrane that are similar to knobs. When brain tissue from B. bovis-infected cattle was examined, cerebral capillaries were packed with PRBC. Infected erythrocytes formed focal attachments with cerebral endothelial cells at the site of these knob-like projections. These findings indicate that cerebral pathology caused by B. bovis is similar to human cerebral malaria. A search for cytoadherence proteins in the endothelial cells may lead to a better understanding of the pathogenisis of cerebral babesiosis.

  5. Magnetic resonance imaging (MRI) of cerebral infarction

    International Nuclear Information System (INIS)

    Fifty-five patients with cerebral infarction were studied with magnetic resonance imaging (MRI) and correlative CT scans. MRI was more sensitive than CT for detecting cerebral infarction, and T2-weighted spin-echo (SE) pulse sequence was most sensitive for detecting cerebral infarction except for some subcortical infarction. The size of infarcted areas on MRI was larger than that on CT in 29 of 51 infarcted areas, equal in 22. The pulse sequence using long repetition time (TR) and double echo delay time (TE), such as SE (2000/30, 90), improved the detectability of cerebral infarction. (author)

  6. Acute cerebral vascular accident associated with hyperperfusion

    International Nuclear Information System (INIS)

    Cerebral radionuclide angiography can demonstrate decreased or normal radioactivity in the affected region during the arterial phase in patients who have sustained a cerebral vascular accident and thus enhances the diagnostic specificity of the static brain image. In an occasional patient, however, a seemingly paradoxical pattern of regional hyperperfusion with a return to normal or subnormal perfusion following the acute phase has been observed. This phenomenon, called luxury perfusion, has been defined using intra-arterial 133Xe for semiquantitative cerebral blood flow measurements and should be kept in mind as a potentially misleading cerebral imaging pattern

  7. Cerebritis: An unusual complication of Klebsiella pneumoniae

    Directory of Open Access Journals (Sweden)

    Majumdar Mainak

    2009-01-01

    Full Text Available Cerebritis is part of a continuum of brain infection and is difficult to diagnose. Cerebritis caused by Klebsiella in immunocompetent adults without predisposing factors such as neurosurgery or penetrating brain injury has not been reported before. We report a case of Klebsiella cerebritis in an adult patient with a proven extracranial focus of infection. We suggest considering cerebritis as a differential diagnosis for altered level of consciousness in patients of severe sepsis, even if an extracranial source of infection is proven.

  8. Wuschel-related homeobox5 gene expression and interaction of CLE peptides with components of the systemic control add two pieces to the puzzle of autoregulation of nodulation.

    Science.gov (United States)

    Osipova, Maria A; Mortier, Virginie; Demchenko, Kirill N; Tsyganov, Victor E; Tikhonovich, Igor A; Lutova, Ludmila A; Dolgikh, Elena A; Goormachtig, Sofie

    2012-03-01

    In legumes, the symbiotic nodules are formed as a result of dedifferentiation and reactivation of cortical root cells. A shoot-acting receptor complex, similar to the Arabidopsis (Arabidopsis thaliana) CLAVATA1 (CLV1)/CLV2 receptor, regulating development of the shoot apical meristem, is involved in autoregulation of nodulation (AON), a mechanism that systemically controls nodule number. The targets of CLV1/CLV2 in the shoot apical meristem, the WUSCHEL (WUS)-RELATED HOMEOBOX (WOX) family transcription factors, have been proposed to be important regulators of apical meristem maintenance and to be expressed in apical meristem "organizers." Here, we focus on the role of the WOX5 transcription factor upon nodulation in Medicago truncatula and pea (Pisum sativum) that form indeterminate nodules. Analysis of temporal WOX5 expression during nodulation with quantitative reverse transcription-polymerase chain reaction and promoter-reporter fusion revealed that the WOX5 gene was expressed during nodule organogenesis, suggesting that WOX genes are common regulators of cell proliferation in different systems. Furthermore, in nodules of supernodulating mutants, defective in AON, WOX5 expression was higher than that in wild-type nodules. Hence, a conserved WUS/WOX-CLV regulatory system might control cell proliferation and differentiation not only in the root and shoot apical meristems but also in nodule meristems. In addition, the link between nodule-derived CLE peptides activating AON in different legumes and components of the AON system was investigated. We demonstrate that the identified AON component, NODULATION3 of pea, might act downstream from or beside the CLE peptides during AON. PMID:22232385

  9. Adenomatous polyposis coli is required for early events in the normal growth and differentiation of the developing cerebral cortex

    OpenAIRE

    Price David J; Mason John O; Chen Yijing; Ivaniutsin Uladzislau; Pratt Thomas

    2009-01-01

    Abstract Background Adenomatous polyposis coli (Apc) is a large multifunctional protein known to be important for Wnt/β-catenin signalling, cytoskeletal dynamics, and cell polarity. In the developing cerebral cortex, Apc is expressed in proliferating cells and its expression increases as cells migrate to the cortical plate. We examined the consequences of loss of Apc function for the early development of the cerebral cortex. Results We used Emx1Cre to inactivate Apc specifically in proliferat...

  10. Adenomatous polyposis coli is required for early events in the normal growth and differentiation of the developing cerebral cortex

    OpenAIRE

    Ivaniutsin, Uladzislau; CHEN, Yijing; John O. MASON; Price, David; Pratt, Thomas

    2009-01-01

    Background: Adenomatous polyposis coli (Apc) is a large multifunctional protein known to be important for Wnt/beta-catenin signalling, cytoskeletal dynamics, and cell polarity. In the developing cerebral cortex, Apc is expressed in proliferating cells and its expression increases as cells migrate to the cortical plate. We examined the consequences of loss of Apc function for the early development of the cerebral cortex.Results: We used Emx1(Cre) to inactivate Apc specifically in proliferating...

  11. Model estimation of cerebral hemodynamics between blood flow and volume changes: a data-based modelling approach

    OpenAIRE

    Wei, H L; Zheng, Y; Pan, Y.; Coca, D.; Li, L M; Mayhew, J.E.W.; S. A. Billings

    2008-01-01

    It is well known that there is a dynamic relationship between cerebral blood flow (CBF) and cerebral blood volume (CBV). With increasing applications of functional magnetic resonance imaging (fMRI), where the blood oxygen level dependent (BOLD) signals are recorded, the understanding and accurate modelling of the hemodynamic relationship between CBF and CBV becomes increasingly important. This study presents an empirical and data-based modelling framework for model identification from CBF and...

  12. Correcting partial volume artifacts of the arterial input function in quantitative cerebral perfusion MRI

    NARCIS (Netherlands)

    van Osch, MJP; Vonken, EJPA; Bakker, CJG; Viergever, MA

    2001-01-01

    To quantify cerebral perfusion with dynamic susceptibility contrast MRI (DSC-MRI), one needs to measure the arterial input function (AIF). Conventionally, one derives the contrast concentration from the DSC sequence by monitoring changes in either the amplitude or the phase signal on the assumption

  13. Ipsilateral Cerebral and Contralateral Cerebellar Hyperperfusion in Patients with Unilateral Cerebral Infarction; SPM Analysis

    International Nuclear Information System (INIS)

    Cortical reorganization has an important role in the recovery of stroke. We analyzed the compensatory cerebral and cerebellar perfusion change in patients with unilateral cerebral infarction using statistical parametric mapping (SPM). Fifty seven 99mTc-Ethylene Cystein Diethylester (ECD) cerebral perfusion SPECT images of 57 patients (male/female=38/19, mean age=56±17 years) with unilateral cerebral infarction were evaluated retrospectively. Patients were divided into subgroups according to the location (left, right) and the onset (acute, chronic) of infarction. Each subgroup was compared with normal controls (male/female=11/1, mean age =36±10 years) in a voxel-by-voxel manner (two sample t-test, p99mTc-ECD SPECT, we observed ipsilateral cerebral and contralateral cerebeller hyperperfusion in patients with cerebral infarction. However, whether these findings are related to the recovery of cerebral functions should be further evaluated

  14. Clinicopathological features of cerebral lipoastrocytoma

    Directory of Open Access Journals (Sweden)

    Shuang WEN

    2014-01-01

    Full Text Available Objective To explore the clinicopathological features, immune phenotype, diagnosis and differential diagnosis, treatment and prognosis of cerebral lipoastrocytoma. Methods Retrospective analysis of the clinical manifestations, histopathological and immunohistochemical features were conducted in one case of cerebral lipoastrocytoma. Results A 48-year-old male presented with numbness and inflexibility of the fourth and little fingers of his left hand over the previous 2 weeks. Cranial MRI revealed a space-occupying lesion with cystic degeneration in the right parietal lobe that showed obvious enhancement after contrast administration. The patient subsequently underwent craniotomy with stereotactic gross total excision of the lesion. Adjuvant chemotherapy and radiation therapy were not administered. Histologically the tumor showed classical features of low-grade astrocytoma, including a few scattered medium-large neuron-like cells with prominent nucleoli and abundant cytoplasm. Most notably, the glial cells contained fat droplets or vacuoles giving an appearance of mature adipocytes. Focally microcystic change was evident resulting from adipocyte-like cells fusion with each other. Immunohistochemically, the tumor cells were reactive for glial fibrillary acidic protein (GFAP and S-100 protein (S-100, focally positive for WT-1, weakly positive for oligodendrocytes transcription factor-2 (Olig-2, and negative for isocitrate dehydrogenase 1 (IDH1. Meanwhile, the tumor cells also expressed several neuronal markers including synaptophysin (Syn, microtube-associated protein-2 (MAP-2, neurofilament (NF, neuron specific enolase (NSE and CD34. P53 protein was weakly expressed in 5% of tumor cells. Ki-67 labeling index was low (1% . The patient remained well without recurrence 20 months after surgery. Conclusions Cerebral lipoastrocytoma is an extremely rare tumor. Histologically, the tumor showed classical features of low-grade astrocytoma and extensive

  15. MRI of sickle cell cerebral infarction

    International Nuclear Information System (INIS)

    Eleven patients with sickle cell disease and neurological symptoms underwent MRI examination. Cerebral infarcts of two types were found, those in the vascular distribution of the middle cerebral artery and those in the deep white matter. In the patient whose hydration and whose oxygenation of erythrocytes has been treated, MRI offers diagnostic advantages over arteriography and CT. (orig.)

  16. Mobility Experiences of Adolescents with Cerebral Palsy

    Science.gov (United States)

    Palisano, Robert J.; Shimmell, Lorie J.; Stewart, Debra; Lawless, John J.; Rosenbaum, Peter L.; Russell, Dianne J.

    2009-01-01

    The purpose of this study was to describe how youth with cerebral palsy experience mobility in their daily lives using a phenomenological approach. The participants were 10 youth with cerebral palsy, 17 to 20 years of age, selected using purposeful sampling with maximum variation strategies. A total of 14 interviews were completed. Transcripts…

  17. Ataxic cerebral palsy and genetic predisposition.

    OpenAIRE

    Miller, G.

    1988-01-01

    It was calculated that in the 962 family members of 36 patients with ataxic cerebral palsy there were 75 (8%) with a history of neurodevelopmental disorder and 31 (3%) with a major congenital malformation. This was not significantly greater than expected, and does not support the hypothesis of a genetic non-Mendelian role in the aetiology of ataxic cerebral palsy.

  18. Fatal cerebral oedema in adult diabetic ketoacidosis.

    NARCIS (Netherlands)

    Haringhuizen, A.; Tjan, D.H.; Grool, A.; Vugt, R. van; Zante, A.R. van

    2010-01-01

    In this report, a case of adult onset fatal cerebral oedema as a rare complication of diabetic ketoacidosis (DKA) is described and confirmed at post-mortem pathological examination. The pathogenesis of cerebral oedema due to DKA is still unknown. Potential mechanisms include the administration of so

  19. Middle cerebral artery blood velocity during running

    DEFF Research Database (Denmark)

    Lyngeraa, Tobias; Pedersen, Lars Møller; Mantoni, T;

    2013-01-01

    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...

  20. Assistive technology for people with cerebral palsy

    OpenAIRE

    Zupan, Anton; Jenko, Mojca

    2013-01-01

    Abstract. Assistive technology includes equipment, devicesand software solutions that increase functional capabilities of people withdisabilities and improve the quality of their lives. The article presentsassistive technology for people with cerebral palsy. These are mobility aidsthat enable people with cerebral palsy independent walking. For those whocannot walk, proper seating is very important. People, who cannot propel manualwheelchair, can control electric wheelchair with various contro...

  1. Mechanical Impedance of Cerebral Material

    Directory of Open Access Journals (Sweden)

    Hédi Ben Ghozlen

    2012-03-01

    Full Text Available The tentative variation of the mechanical impedance, of a cylindrical sample of cerebral material, has been achieved by Vibrometer Laser according to the frequency. The studied matter is supposed homogeneous, isotropic and stationary. A multilayered mechanical model has been associated to the studied sample to simulate its vibration. The theoretical expression of mechanical impedance has been determined while taking the mechanical/electric analogy as a basis. A good adjustment of theoretical model parameters permitted us to have a good agreement theory/experience of the mechanical impedance variation according to the sample vibration frequency.

  2. Cerebral blood-flow tomography

    DEFF Research Database (Denmark)

    Lassen, N A; Henriksen, L; Holm, S;

    1983-01-01

    Tomographic maps of local cerebral blood flow (CBF) were obtained with xenon-133 and with isopropyl-amphetamine-iodine-123 (IMP) in 11 subjects: one normal, two tumor cases, and eight cerebrovascular cases. A highly sensitive four-face, rapidly rotating, single-photon emission tomograph was used...... sampling, and with low radiation exposure to patient and personnel. On the other hand, IMP gives an image of slightly higher resolution. It also introduces a new class of iodinated brain-seeking compounds allowing, perhaps, imaging of other functions more important than mere blood flow....

  3. ECG changes during cerebral angiography

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, K.; Nishimura, Y.; Yoshida, M.; Itoh, K.; Hayashi, N.; Aoki, J.; Nakamura, K.; Imai, M.; Ono, T.; Morikawa, S.

    1984-09-01

    We have analyzed HR changes greater than 20% among 334 patients and 942 cerebral angiographies. A tachycardial effect was seen in 14.9% of patients, while a bradycardial effect was seen in 7.1% including two patients having cardiac standstill (0.5%). These two patients were examined without atropine premedication after subarachnoid hemorrhage. Patients under 19 years of age, unpremedicated with atropine sulfate and suffering from subarachnoid hemorrhage secondary to ruptured aneurysm or arteriovenous malformation showed a significantly high incidence of bradycardia. On the other hand, patients with the neoplastic disease and having an initial sinus bradycardia showed a significantly high incidence of a tachycardial effect.

  4. A Family of Salmonella Virulence Factors Functions as a Distinct Class of Autoregulated E3 Ubiquitin Ligases

    Energy Technology Data Exchange (ETDEWEB)

    Quezada, C.; Hicks, S; Galan, J; Stebbins, C

    2009-01-01

    Processes as diverse as receptor binding and signaling, cytoskeletal dynamics, and programmed cell death are manipulated by mimics of host proteins encoded by pathogenic bacteria. We show here that the Salmonella virulence factor SspH2 belongs to a growing class of bacterial effector proteins that harness and subvert the eukaryotic ubiquitination pathway. This virulence protein possesses ubiquitination activity that depends on a conserved cysteine residue. A crystal structure of SspH2 reveals a canonical leucine-rich repeat (LRR) domain that interacts with a unique E{sub 3} ligase [which we have termed NEL for Novel E{sub 3} Ligase] C-terminal fold unrelated to previously observed HECT or RING-finger E{sub 3} ligases. Moreover, the LRR domain sequesters the catalytic cysteine residue contained in the NEL domain, and we suggest a mechanism for activation of the ligase requiring a substantial conformational change to release the catalytic domain for function. We also show that the N-terminal domain targets SspH2 to the apical plasma membrane of polarized epithelial cells and propose a model whereby binding of the LRR to proteins at the target site releases the ligase domain for site-specific function.

  5. CT findings in patients with cerebral palsy

    Energy Technology Data Exchange (ETDEWEB)

    Konno, K. (Akita Univ. (Japan))

    1982-01-01

    Clinical findings and CT findings in 73 cases of cerebral palsy were studied. The causes of cerebral palsy were presumed to be as follows: abnormal cerebral development (36%), asphyxial delivery (34%), and immature delivery (19%), etc. CT findings were abnormal in 58% of the 73 cases, 83% of the spastic tetraplegia patients and all of the spastic hemiplegia patients showed abnormal CT findings. All the patients with spastic monoplegia presented normal CT findings. In 75% of the spastic hemiplegia cases, the CT abnormalities were due to cerebral parenchymal abnormality such as porencephaly and regional low absorption. In cases of spastic tetraplegia, cerebral parenchymal abnormality was found only in 10%. Cortical atrophy was found only in 15 of the 73 cases, whereas central atrophy was found in 36 cases.

  6. CT findings in patients with cerebral palsy

    International Nuclear Information System (INIS)

    Clinical findings and CT findings in 73 cases of cerebral palsy were studied. The causes of cerebral palsy were presumed to be as follows: abnormal cerebral development (36%), asphyxial delivery (34%), and immature delivery (19%), etc. CT findings were abnormal in 58% of the 73 cases, 83% of the spastic tetraplegia patients and all of the spastic hemiplegia patients showed abnormal CT findings. All the patients with spastic monoplegia presented normal CT findings. In 75% of the spastic hemiplegia cases, the CT abnormalities were due to cerebral parenchymal abnormality such as porencephaly and regional low absorption. In cases of spastic tetraplegia, cerebral parenchymal abnormality was found only in 10%. Cortical atrophy was found only in 15 of the 73 cases, whereas central atrophy was found in 36 cases. (Ueda, J.)

  7. Validation of CFD Simulations of Cerebral Aneurysms With Implication of Geometric Variations

    OpenAIRE

    Hoi, Yiemeng; Woodward, Scott H.; Kim, Minsuok; Taulbee, Dale B.; Meng, Hui

    2006-01-01

    Computational fluid dynamics (CFD) simulations using medical-image-based anatomical vascular geometry are now gaining clinical relevance. This study aimed at validating the CFD methodology for studying cerebral aneurysms by using particle image velocimetry (PIV) measurements, with a focus on the effects of small geometric variations in aneurysm models on the flow dynamics obtained with CFD. Method of Approach. An experimental phantom was fabricated out of silicone elastomer to best mimic a sp...

  8. Cerebral blood flow changes during sodium-lactate-induced panic attacks

    International Nuclear Information System (INIS)

    Dynamic single-photon emission computed axial tomography (CAT) with inhaled xenon-133 was used to measure regional cerebral blood flow in 10 drug-free patients with DSM-III-diagnosed panic disorder and in five normal control subjects. All subjects underwent regional cerebral blood flow studies while at rest or during normal saline infusion and during sodium lactate infusion. Six of the 10 patients and none of the control subjects experienced lactate-induced panic attacks. Lactate infusion markedly raised hemispheric blood flow levels in both control subjects and patients who did not panic. Patients who did panic experienced either a minimal increase or a decrease in hemispheric blood flow

  9. Cerebral perfusion and cerebrovascular reactivity are reduced in white matter hyperintensities

    DEFF Research Database (Denmark)

    Marstrand, J.R.; Garde, E; Rostrup, Egill;

    2002-01-01

    reported global reductions in cerebral blood flow (CBF) and cerebral vascular reactivity. In this study, we examined localized hemodynamic status to compare WMH to normal appearing white matter (NAWM). METHODS: A group of 21 normal 85-year-old subjects were studied using dynamic contrast-enhanced MRI...... NAWM (P=0.026, P<0.001). CONCLUSION: These results show that a change in the hemodynamic status is present within the WMH, making these areas more likely to be exposed to transient ischemia inducing myelin rarefaction. In the future, MRI may be used to examine the effect of therapeutic strategies...

  10. Cerebral cortex modulation of pain

    Institute of Scientific and Technical Information of China (English)

    Yu-feng XIE; Fu-quan HUO; Jing-shi TANG

    2009-01-01

    Pain is a complex experience encompassing sensory-discriminative, affective-motivational and cognitiv e-emotional com-ponents mediated by different mechanisms. Contrary to the traditional view that the cerebral cortex is not involved in pain perception, an extensive cortical network associated with pain processing has been revealed using multiple methods over the past decades. This network consistently includes, at least, the anterior cingulate cortex, the agranular insular cortex, the primary (SⅠ) and secondary somatosensory (SⅡ) cortices, the ventrolateral orbital cortex and the motor cortex. These corti-cal structures constitute the medial and lateral pain systems, the nucleus submedius-ventrolateral orbital cortex-periaque-ductal gray system and motor cortex system, respectively. Multiple neurotransmitters, including opioid, glutamate, GABA and dopamine, are involved in the modulation of pain by these cortical structures. In addition, glial cells may also be in-volved in cortical modulation of pain and serve as one target for pain management research. This review discusses recent studies of pain modulation by these cerebral cortical structures in animals and human.

  11. [Cerebral vasospasm after subarachnoid hemorrhage].

    Science.gov (United States)

    Milojević, T M; Baljozović, B V; Rakić, M Lj; Nestorović, B D; Dostanić, M M; Milaković, B D; Kojić, Z Z; Repac, N R; Cvrkota, I S

    2008-01-01

    Cerebral vasospasm causes permanent neurolological deficit or death occurance in 13% of clinical cases. Peak frequency is from 8-10th day after SAH. The purpose of this study is factor analysis that may have influence on vasospasm development , as well as predictor determination. The study is prospective and analysis 192 patients treated in Institute of Neurosurgery, Clinical Centre of Serbia, Belgrade. The majority of patients were admitted in hospital in first four days after SAH, and 184 had GCS over 7. Univariate methods of factor analysis were used, and for significance of predictors influence testing multivariante regression analysis was used. Vasospasm occurred in 22,40% of all cases. No relationships have been found between sex, age, previous hypertension, timing of surgery, appearance of hydrocephalus and intracerebral hematoma, hypertermia or mean arterial blood pressure, with occurrence of cerebral vasospasm. Factors with significantly associated with the occurance of vasospasm were: hearth disease, hypernatriemia, Hct, clinical grade on admission as well as preoperative clinical grade and Fisher CT scan grade. In the first four days after SAH, Fisher scan grade, preoperative clinical grade and Hct, appeared as predictors. After four days, clinical grade on admission and hypernatiemia, showed as poredictors. PMID:18792575

  12. Cerebral lateralization in simultaneous interpretation.

    Science.gov (United States)

    Fabbro, F; Gran, L; Basso, G; Bava, A

    1990-07-01

    Cerebral asymmetries for L1 (Italian), L2 (English), and L3 (French, German, Spanish, or Russian) were studied, by using a verbal-manual interference paradigm, in a group of Italian right-handed polyglot female students at the Scuola Superiore di Lingue Moderne per Interpreti e Traduttori (SSLM-School for Interpreters and Translators) of the University of Trieste and in a control group of right-handed monolingual female students at the Medical School of the University of Trieste. In an automatic speech production task no significant cerebral lateralization was found for the mother tongue (L1) either in the interpreting students or in the control group; the interpreting students were not significantly lateralized for the third language (L3), while weak left hemispheric lateralization was shown for L2. A significantly higher degree of verbal-manual interference was found for L1 than for L2 and L3. A significantly higher disruption rate occurred in the meaning-based mode of simultaneous interpretation (from L2 into L1 and vice versa) than in the word-for-word mode (from L2 into L1 and vice versa). No significant overall or hemispheric differences were found during simultaneous interpretation from L1 into L2 or from L2 into L1. PMID:2207622

  13. MRI of acute cerebral infarction

    International Nuclear Information System (INIS)

    Sequential changes of magnetic resonance imaging (MRI) in sixteen patients with acute cerebral infarction are studied in comparison with the findings of computed tomography (CT). The sixteen patients were examined within 36 hours from the onset of syptoms on resistive type MRI (0.15T) using T1 weighted image (IR2000/500) and T2 weighted image (SE2000/80), and on CT. In general, large infarcted lesions of the cortexsubcortex seemed to be visualized earlier than small lesions of the basal ganglia and brainstem. In 8 patients, the infarcted lesions were detected on MRI earlier than on CT. For example, early detecting time within 12 hours were 2, 6, 7, and 10 hours after onset. In two patients of this group, lesions were detected on T2 weighted image earlier than on T1-weighted image. In two cases, small lesions of the brainstem were detected only on MRI. The size of abnormal findings gradually developed and reached a maximum on days 5 to 7 sequentially. The difference between infarction and perifocal edema was not clear even on MRI. The changes gradually subsided and assumed a stable size after about 2 months. Contrast enhancement effect was observed in four patients. In two of these cases, the signal intensity of T2-weighted imaging was decreased just at the region which was enhanced with contrast medium. MRI is useful for early diagnosis of ischemic cerebral infarction, and may eludidate some aspects of the pathophysiology of ischemic stroke. (author)

  14. Cerebrovascular regulation in the postural orthostatic tachycardia syndrome (POTS)

    Science.gov (United States)

    Low, P. A.; Novak, V.; Spies, J. M.; Novak, P.; Petty, G. W.

    1999-01-01

    Patients with the postural orthostatic tachycardia syndrome (POTS) have symptoms of orthostatic intolerance despite having a normal orthostatic blood pressure (BP), which suggests some impairment of cerebrovascular regulation. Cerebrovascular autoregulation refers to the maintenance of normal cerebral blood flow in spite of changing BP. Mechanisms of autoregulation include myogenic, metabolic and neurogenic vasoregulation. Beat-to-beat recording of blood-flow velocity (BFV) is possible using transcranial Doppler imaging. It is possible to evaluate autoregulation by regressing deltaBFV to deltaBP during head-up tilt. A number of dynamic methods, relating deltaBFV to deltaBP during sudden induced changes in BP by occluding then releasing peripheral arterial flow or by the Valsalva maneuver. The deltaBFV to deltaBP provides an index of autoregulation. In orthostatic hypotension, the autoregulated range is typically expanded. In contrast, paradoxical vasoconstriction occurs in POTS because of an increased depth of respiration, resulting in hypocapnic cerebrovascular constriction, and impaired autoregulation.

  15. The influence of tobacco smoking on the relationship between pressure and flow in the middle cerebral artery in humans.

    Directory of Open Access Journals (Sweden)

    Karen C Peebles

    Full Text Available BACKGROUND: Cigarette smoking is associated with an increased risk of stroke but the mechanism is unclear. The study examined whether acute and chronic cigarette smoking alters the dynamic relationship between blood pressure and cerebral blood flow. We hypothesised that acute and chronic smoking would result in a cerebral circulation that was less capable of buffering against dynamic fluctuations in blood pressure. Further, these changes would be accompanied by a reduction in baroreflex sensitivity, which is reduced after smoking (acute smoking. METHODS: We recruited 17 non-smokers and 15 habitual smokers (13 ± 5 pack years. Continuous measurements of mean cerebral blood flow velocity (transcranial Doppler ultrasound, blood pressure (finger photoplethysmography and heart rate enabled transfer function analysis of the dynamic relationship between pressure and flow (gain, normalised gain, phase and coherence and baroreflex sensitivity during supine rest before and after smoking a single cigarette (acute smoking. RESULTS: There were no between-group differences in gain, phase or coherence before acute smoking. However, both groups showed a reduction in gain and coherence, associated with a reduction in baroreflex sensitivity, and increase in phase after acute smoking. CONCLUSIONS: Contrary to our hypothesis, these findings suggest that in the face of a reduction in baroreflex sensitivity acute smoking may potentially improve the ability of the cerebral circulation to buffer against changes in blood pressure. However, chronic smoking did not alter the dynamic relationship between blood pressure and cerebral blood flow velocity. These results have implications on understanding mechanisms for attenuating stroke risk.

  16. Caring for Children with Cerebral Palsy: A Team Approach.

    Science.gov (United States)

    Dormans, John P., Ed.; Pellegrino, Louis, Ed.

    Twenty-one papers on caring for children with cerebral palsy are organized into four sections, including: (1) cerebral palsy and the interdisciplinary team approach; (2) management of impairments related to cerebral palsy; (3) preventing disability by optimizing function of the child with cerebral palsy; and (4) preventing handicap by creating…

  17. Imaging of rat cerebral ischemia-reperfusion injury using99mTc-labeled duramycin

    International Nuclear Information System (INIS)

    Objectives: Prompt identification of necrosis and apoptosis in the infarct core and penumbra region is critical in acute stroke for delineating the underlying ischemic/reperfusion molecular pathologic events and defining therapeutic alternatives. The objective of this study was to investigate the capability of 99mTc-labeled duramycin in detecting ischemia-reperfusion injury in rat brain after middle cerebral artery (MCA) occlusion. Methods: Ischemic cerebral injury was induced in ten rats by vascular insertion of a nylon suture in the left MCA for 3 hr followed by 21–24 hr reperfusion. After i.v. injection of 99mTc-duramycin (1.0-3.5 mCi), dynamic cerebral images were acquired for 1 hr in six rats using a small-animal SPECT imager. Four other rats were imaged at 2 hr post-injection. Ex vivo images were obtained by autoradiography after sacrifice. Histologic analyses were performed to assess cerebral infarction and apoptosis. Results: SPECT images showed that 99mTc-duramycin uptake in the left cerebral hemisphere was significantly higher than that in the right at 1 and 2 hr post-injection. The level of radioactive uptake in the ischemic brain varied based on ischemic severity. The average ratio of left cerebral hot-spot uptake to right hemisphere radioactivity, as determined by computerized ROI analysis, was 4.92 ± 0.79. Fractional washout at 1 hr was 38.2 ± 4.5% of peak activity for left cerebral hot-spot areas and 80.9 ± 2.0% for remote control areas (P 99mTc-duramycin SPECT imaging may be useful for detecting and quantifying ongoing apoptotic neuronal cell loss induced by ischemia-reperfusion injury.

  18. Regulation of cerebral cortex development by Rho GTPases: insights from in vivo studies

    Directory of Open Access Journals (Sweden)

    Roberta eAzzarelli

    2015-01-01

    Full Text Available The cerebral cortex is the site of higher human cognitive and motor functions. Histologically, it is organized into six horizontal layers, each containing unique populations of molecularly and functionally distinct excitatory projection neurons and inhibitory interneurons. The stereotyped cellular distribution of cortical neurons is crucial for the formation of functional neural circuits and it is predominantly established during embryonic development. Cortical neuron development is a multiphasic process characterized by sequential steps of neural progenitor proliferation, cell cycle exit, neuroblast migration and neuronal differentiation. This series of events requires an extensive and dynamic remodeling of the cell cytoskeleton at each step of the process. As major regulators of the cytoskeleton, the family of small Rho GTPases has been shown to play essential functions in cerebral cortex development. Here we review in vivo findings that support the contribution of Rho GTPases to cortical projection neuron development and we address their involvement in the etiology of cerebral cortex malformations.

  19. Quantitative cerebral perfusion assessment using microscope-integrated analysis of intraoperative indocyanine green fluorescence angiography versus positron emission tomography in superficial temporal artery to middle cerebral artery anastomosis

    Directory of Open Access Journals (Sweden)

    Shinya Kobayashi

    2014-01-01

    Full Text Available Background: Intraoperative qualitative indocyanine green (ICG angiography has been used in cerebrovascular surgery. Hyperperfusion may lead to neurological complications after superficial temporal artery to middle cerebral artery (STA-MCA anastomosis. The purpose of this study is to quantitatively evaluate intraoperative cerebral perfusion using microscope-integrated dynamic ICG fluorescence analysis, and to assess whether this value predicts hyperperfusion syndrome (HPS after STA-MCA anastomosis. Methods: Ten patients undergoing STA-MCA anastomosis due to unilateral major cerebral artery occlusive disease were included. Ten patients with normal cerebral perfusion served as controls. The ICG transit curve from six regions of interest (ROIs on the cortex, corresponding to ROIs on positron emission tomography (PET study, was recorded. Maximum intensity (I MAX , cerebral blood flow index (CBFi, rise time (RT, and time to peak (TTP were evaluated. Results: RT/TTP, but not I MAX or CBFi, could differentiate between control and study subjects. RT/TTP correlated (|r| = 0.534-0.807; P < 0.01 with mean transit time (MTT/MTT ratio in the ipsilateral to contralateral hemisphere by PET study. Bland-Altman analysis showed a wide limit of agreement between RT and MTT and between TTP and MTT. The ratio of RT before and after bypass procedures was significantly lower in patients with postoperative HPS than in patients without postoperative HPS (0.60 ± 0.032 and 0.80 ± 0.056, respectively; P = 0.017. The ratio of TTP was also significantly lower in patients with postoperative HPS than in patients without postoperative HPS (0.64 ± 0.081 and 0.85 ± 0.095, respectively; P = 0.017. Conclusions: Time-dependent intraoperative parameters from the ICG transit curve provide quantitative information regarding cerebral circulation time with quality and utility comparable to information obtained by PET. These parameters may help predict the occurrence of postoperative

  20. Cerebral Hypoperfusion Precedes Nausea During Centrifugation

    Science.gov (United States)

    Serrador, Jorge M.; Schlegel, Todd T.; Black, F. Owen; Wood, Scott J.

    2004-01-01

    Nausea and motion sickness are important operational concerns for aviators and astronauts. Understanding underlying mechanisms associated with motion sickness may lead to new treatments. The goal of this work was to determine if cerebral blood flow changes precede the development of nausea in motion sick susceptible subjects. Cerebral flow velocity in the middle cerebral artery (transcranial Doppler), blood pressure (Finapres) and end-tidal CO2 were measured while subjects were rotated on a centrifuge (250 degrees/sec). Following 5 min of rotation, subjects were translated 0.504 m off-center, creating a +lGx centripetal acceleration in the nasal-occipital plane. Ten subjects completed the protocol without symptoms while 5 developed nausea (4 while 6ff-center and 1 while rotating on-center). Prior to nausea, subjects had significant increases in blood pressure (+13plus or minus 3 mmHg, P less than 0.05) and cerebrovascular resistance (+46 plus or minus 17%, P less than 0.05) and decreases in cerebral flow velocity both in the second (-13 plus or minus 4%) and last minute (-22 plus or minus 5%) before symptoms (P less than 0.05). In comparison, controls demonstrated no change in blood pressure or cerebrovascular resistance in the last minute of off-center rotation and only a 7 plus or minus 2% decrease in cerebral flow velocity. All subjects had significant hypocapnia (-3.8 plus or minus 0.4 mmHg, P less than 0.05), however this hypocapnia could not fully explain the cerebral hypoperfusion associated with the development of nausea. These data indicate that reductions in cerebral blood flow precede the development of nausea. Further work is necessary to determine what role cerebral hypoperfusion plays in motion sickness and whether cerebral hypoperfusion can be used to predict the development of nausea in susceptible individuals.

  1. Adenomatous polyposis coli is required for early events in the normal growth and differentiation of the developing cerebral cortex

    Directory of Open Access Journals (Sweden)

    Price David J

    2009-01-01

    Full Text Available Abstract Background Adenomatous polyposis coli (Apc is a large multifunctional protein known to be important for Wnt/β-catenin signalling, cytoskeletal dynamics, and cell polarity. In the developing cerebral cortex, Apc is expressed in proliferating cells and its expression increases as cells migrate to the cortical plate. We examined the consequences of loss of Apc function for the early development of the cerebral cortex. Results We used Emx1Cre to inactivate Apc specifically in proliferating cerebral cortical cells and their descendents starting from embryonic day 9.5. We observed reduction in the size of the mutant cerebral cortex, disruption to its organisation, and changes in the molecular identity of its cells. Loss of Apc leads to a decrease in the size of the proliferative pool, disrupted interkinetic nuclear migration, and increased apoptosis. β-Catenin, pericentrin, and N-cadherin proteins no longer adopt their normal high concentration at the apical surface of the cerebral cortical ventricular zone, indicating that cell polarity is disrupted. Consistent with enhanced Wnt/β-catenin signalling resulting from loss of Apc we found increased levels of TCF/LEF-dependent transcription and expression of endogenous Wnt/β-catenin target genes (Axin2 (conductin, Lef1, and c-myc in the mutant cerebral cortex. In the Apc mutant cerebral cortex the expression of transcription factors Foxg1, Pax6, Tbr1, and Tbr2 is drastically reduced compared to normal and many cells ectopically express Pax3, Wnt1, and Wt1 (but not Wnt2b, Wnt8b, Ptc, Gli1, Mash1, Olig2, or Islet1. This indicates that loss of Apc function causes cerebral cortical cells to lose their normal identity and redirect to fates normally found in more posterior-dorsal regions of the central nervous system. Conclusion Apc is required for multiple aspects of early cerebral cortical development, including the regulation of cell number, interkinetic nuclear migration, cell polarity, and

  2. Validation of a cerebral palsy register

    DEFF Research Database (Denmark)

    Topp, Monica Wedell; Langhoff-Roos, J; Uldall, P

    1997-01-01

    OBJECTIVES: To analyse completeness and validity of data in the Cerebral Palsy Register in Denmark, 1979-1982. METHODS: Completeness has been assessed by comparing data from The Danish National Patient Register (DNPR) with the cases included in the Cerebral Palsy Register (CPR). Agreement between...... gestational age was subject to a systematic error, and urinary infections in pregnancy (kappa = 0.43) and placental abruption (kappa = 0.52) were seriously under-reported in the CPR. CONCLUSIONS: Completeness of the Cerebral Palsy Register in Denmark, 1979-1982, has been assessed to maximal 85%, emphasizing...

  3. EPILEPSY IN CHILDREN WITH CEREBRAL PALSY

    OpenAIRE

    S. Pour Ahmadi; M. Jafarzadeh; Abbas, M; J Akhondian

    2008-01-01

    ObjectiveEpilepsy occurs in 12 % to 90 % of children with cerebral palsy (CP). However its clinical course is not well defined. This investigation was undertaken to study and determine the characteristics and prevalence of epilepsy in children with cerebral palsy.Materials & MethodsOf 133 children with cerebral palsy, seen between 1998 and 2001, in the pediatric neurology clinic of the Imam Reza hospital, fifty-three had epilepsy.During the same period, a group of 70 epileptic children with n...

  4. The serpentine mitral valve and cerebral embolism

    Directory of Open Access Journals (Sweden)

    Ker James

    2011-02-01

    Full Text Available Abstract Valvular strands, well-delineated filiform masses, attached to cardiac valve edges are associated with cerebral embolism and stroke. Strokes, caused by emboli from valvular strands, tend to occur among younger persons. In this case report a valvular strand, giving a peculiar serpentine appearance to the mitral valve is described. This mitral valvular strand was the only explanation for an episode of cerebral embolism, presenting with a transient right sided hemiparesis. It is proposed that a randomized study involving combined treatment with aspirin and clopidogrel is warranted in young patients with valvular strands, presenting with a first episode of cerebral embolism.

  5. Trends in birth prevalence of cerebral palsy.

    OpenAIRE

    Pharoah, P O; Cooke, T.; Rosenbloom, I; Cooke, R W

    1987-01-01

    A register of children with cerebral palsy born in the period 1966-77 to mothers resident in the Mersey region was compiled from several different data sources. There were 685 cases, with a male:female ratio of 1.4:1. The birth prevalence of cerebral palsy ranged from 1.18 to 1.97 per 1000 live births each year, with a mean of 1.51 per 1000 live births. There was no discernible trend in overall prevalence, but there was a highly significant upward trend in the prevalence of cerebral palsy amo...

  6. Cerebral Metabolic Alterations in Rats With Diabetic Ketoacidosis

    OpenAIRE

    Glaser, Nicole; Yuen, Natalie; Anderson, Steven E; Tancredi, Daniel J.; O'Donnell, Martha E.

    2009-01-01

    OBJECTIVE Cerebral edema is a life-threatening complication of diabetic ketoacidosis (DKA) in children. Recent data suggest that cerebral hypoperfusion and activation of cerebral ion transporters may be involved, but data describing cerebral metabolic alterations during DKA are lacking. RESEARCH DESIGN AND METHODS We evaluated 50 juvenile rats with DKA and 21 normal control rats using proton and phosphorus magnetic resonance spectroscopy (MRS). MRS measured cerebral intracellular pH and ratio...

  7. Role of Aquaporin-4 in Cerebral Edema and Stroke

    OpenAIRE

    Zador, Zsolt; Stiver, Shirley; Wang, Vincent; Manley, Geoffrey T.

    2009-01-01

    Cerebral edema plays a central role in the pathophysiology of many diseases of the central nervous system (CNS) including ischemia, trauma, tumors, inflammation, and metabolic disturbances. The formation of cerebral edema results in an increase in tissue water content and brain swelling which, if unchecked, can lead to elevated intracranial pressure (ICP), reduced cerebral blood flow, and ultimately cerebral herniation and death. Despite the clinical significance of cerebral edema, the mechan...

  8. Evaluation of cerebral hemodynamics by sup 123 I-IMP in cerebral AVMs before and after operation by using SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Toyama, Hiroshi; Takeshita, Gen; Takeuchi, Akira (Fujita-Gakuen Health Univ., Toyoake, Aichi (Japan)) (and others)

    1989-12-01

    To evaluate cerebral hemodynamics by N-isopropyl-p-({sup 123}I)-iodoamphetamine ({sup 123}I-IMP) preoperative and postoperative (after 1 day, and after 7-10 days) regional cerebral blood flow scan, 6 arteriovenous malformations (AVMs) which performed total removal operations were studied by using a ring type SPECT 'HEADTOME'. We performed the dynamic scan just after the intravenous injection of 222 MBq (6 mCi) of {sup 123}I-IMP, then the static scan 20 minutes after the intravenous injection. In preoperative dynamic scans of all cases, only the first frame image showed the increased activity on the nidus probably because of the blood pool. Preoperative static scans of all cases showed the remarkable decreased activity on the nidus, and decreased activity surrounding the nidus probably because of the peripheral steal phenomenon. In postoperative scan of the next day, 4 out of 6 cases showed the transient decreased peripheral steal, particularly 2 out of those 4 cases showed the transient hyperperfusion probably because of the normal perfusion pressure break-through (NPPB). And, 2 out of 6 cases showed transient peripheral low perfusion on much larger area than those of the preoperative scans probably because of the focal brain damages and edemas. We conclude that {sup 123}I-IMP SPECT on AVM is very useful to decide the indication of the removal operation, and to estimate the postoperative risk, and to evaluate the preoperative and postoperative cerebral hemodynamic changes in the peripheral area of AVM. (author).

  9. Clinical significance of determination of plasma NPY levels and serum lipid profile in patients with cerebral hemorrhage and cerebral infarction

    International Nuclear Information System (INIS)

    Objective: To study the clinical significance of changes of plasma NPY levels and serum lipid profile in patients with cerebral hemorrhage and cerebral infarction. Methods: Plasma NPY levels (with RIA) and serum lipid profile (with biochemistry) were determined in (1) 48 patients with acute cerebral hemorrhage (2) 46 patients with acute cerebral infarction and (3) controls.Results Plasma NPY levels in both patients with cerebral hemorrhage and patients with cerebral infarction were significantly higher than those in controls (P0.05). Conclusion: NPY played important roles in the development and pathogenesis of cerebral vascular accidents. Lipid profile changes was the basic etiological factor. (authors)

  10. Epilepsy in children with cerebral palsy Epilepsia em crianças com paralisia cerebral

    OpenAIRE

    Isac Bruck; Sérgio Antônio Antoniuk; Adriane Spessatto; Ricardo Schmitt de Bem; Romeu Hausberger; Carlos Gustavo Pacheco

    2001-01-01

    OBJECTIVE: To describe the prevalence and characteristics of epilepsy in patients with cerebral palsy in a tertiary center. METHODS: a total of 100 consecutive patients with cerebral palsy were retrospectively studied. Criteria for inclusion were follow-up period for at least 2 years. Types and incidence of epilepsy were correlated with the different forms of cerebral palsy. Other factors associated with epilepsy such as age of first seizure, neonatal seizures and family history of epilepsy w...

  11. Endovascular therapy of cerebral AVMs

    International Nuclear Information System (INIS)

    This paper evaluates the results of completed endovascular treatment on all patients with cerebral arteriovenous malformations (AVMs). Between 1985 and 1989, 125 patients with AVMs completed endovascular treatment. Treatment decisions were made by means of multidisciplinary consultation (neuroradiology, neurosurgery, neurology, and radiation therapy) depending on the presentation, location, size, and angioarchitecture of the lesion (hemorrhage in 87 patients, seizures in seven, headaches in nine, and progressive neurologic deficit in 22). Superselective catheterization of feeding pedicles to the AVM nidus was performed with either microcatheters delivered by a propulsion chamber or variable-stiffness catheters. Tiny quantities (0.08--0.15 mL) or varying dilutions of NBCA Pantopaque were injected by means of a sandwich technique, drop by drop

  12. Computed tomography of cerebral palsy

    International Nuclear Information System (INIS)

    Seventy patients who had suffered from severe damages in the brain in their early lives were examined using a CT scanner, DELTA-25. The results are summerized as follows: 1. CT findings of the brain were classified into four groups; (1) low density in 11 cases, (2) atrophy in 23, (3) hydrocephalus in 12, and (4) no findings in 24. 2. The low density in the CT finding was assumed as cystic degeneration due to circulatory disturbance in the cerebral hemispheres in their early developmental stages. 3. The ''acerebrate'' state denotes no or little development in mental and motor functions which is attributed to a severe damage in the developing brain. According to the CT findings, the ''acerebrate'' state was resulted from extensive destruction in the greater part of both hemispheres. (author)

  13. Cerebral astroblastoma: A radiopathological diagnosis

    Directory of Open Access Journals (Sweden)

    Deepak Kumar Singh

    2014-01-01

    Full Text Available Astroblastoma is a rare glial neoplasm whose histogenesis has been clarified recently. It primarily occurs in children and young adults. We are reporting a case of 12-year-old girl child who presented with features of raised intracranial tension and generalized tonic-clonic seizures. Brain magnetic resonance imaging revealed a large well-circumscribed, cystic lesion without perifocal edema, and enhancing mural nodule in right parietal region. A radiological differential diagnosis of pilocytic astrocytoma and cerebral astroblastoma was made. A complete excision was done and histologically the lesion turned out to be an astroblastoma. We review the histology, immunohistochemistry, and imaging features of astroblastoma and survey the current literature, treatment strategies, and prognostic aspects for the management of this rare neoplasm.

  14. A case of cerebral cryptococcosis

    International Nuclear Information System (INIS)

    A 66-year-old female was admitted to our hospital with chief complaint of vertigo, gait disturbance and dysarthria. These symptoms started about one year before admission and worsened. Vomiting and urinary incontinence appeared. Neurological examination revealed left cerebellar ataxia and dysarthria. In plain CT (computerized tomography) irregular ill-defined low density area was noted in the cerebellar vermis and bilateral cerebellar hemispheres. And slight ventricular dilatation was found. Irregular shape of ring-like enhancement corresponding to capsule and patchy or mottled enhancement inside the tumor were seen. Suboccipital craniectomy was performed and yellowish necrotic tumor with hard capsule was removed. Histological diagnosis was not neoplasm or tuberculoma. Postoperatively liver function progressively worsened. She died due to disseminated intravascular coagulation. Autopsy revealed typical liver cirrhosis without malignant change. 3.0 x 2.5 cm sized, slightly hard, yellowish lesion was found on upper part of cerebellar hemispheres. This had extremely necrotic tissue and a great number of cryptococcus neoformans were found. And other intracranial lesion was not confirmed. Finding of pulmonary cryptococcosis was not gained. Our case is very rare because of solitary cerebellar abscess and absence of meningitic episode or pulmonary cryptococcosis. There are three types of inflammation in cerebral cryptococcosis. The commonest manifestation is the meningitic type, the second mode is granulomatous lesion and the third and the least presentation is intracranial abscess formatior. CT reveals various finidngs according to clinical stage. CT findings are those of meningitis, meningoencephalitis, granuloma and abscess. Cryptococcal granuloma or abscess often simulates brain abscess, glioma and metastatic brain tumor. We discussed CT findings of cerebral cryptococcosis and examined the CT number of our case. (J.P.N.)

  15. Effect of prostaglandin E1 on cerebral blood flow in patients with chronic cerebral infarction

    International Nuclear Information System (INIS)

    The effect of prostaglandin E1 (PGE1) on cerebral blood flow (CBF) was studied in 10 patients with chronic cerebral infarction. Regional cerebral blood flow (rCBF) was measured by single photon emission computed tomography before and after they received PGE1 120 μg daily for 2 weeks. The rCBF of the brainstem, cerebellum, and frontal, temporal, and parietal lobes increased significantly after PGE1 administration. PGE1 also significantly increased the rCBF of the non-infarcted area adjacent to infarction. The results indicate that PGE1 increases the CBF of patients with chronic cerebral infarction without causing the intracerebral steal phenomenon. (author)

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

    International Nuclear Information System (INIS)

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

  17. Ipsilateral Cerebral and Contralateral Cerebellar Hyperperfusion in Patients with Unilateral Cerebral Infarction; SPM Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sun Pyo; Yoon, Joon Kee; Choi, Bong Hoi; Joo, In Soo; Yoon, Seok Nam [Ajou University School of Medicine, Suwon (Korea, Republic of)

    2008-10-15

    Cortical reorganization has an important role in the recovery of stroke. We analyzed the compensatory cerebral and cerebellar perfusion change in patients with unilateral cerebral infarction using statistical parametric mapping (SPM). Fifty seven {sup 99m}Tc-Ethylene Cystein Diethylester (ECD) cerebral perfusion SPECT images of 57 patients (male/female=38/19, mean age=56{+-}17 years) with unilateral cerebral infarction were evaluated retrospectively. Patients were divided into subgroups according to the location (left, right) and the onset (acute, chronic) of infarction. Each subgroup was compared with normal controls (male/female=11/1, mean age =36{+-}10 years) in a voxel-by-voxel manner (two sample t-test, p<0.001) using SPM. All 4 subgroups showed hyperperfusion in the ipsilateral cerebral cortex, but not in the contralateral cerebral cortex. Chronic left and right infarction groups revealed hyperperfusion in the ipsilateral primary sensorimotor cortex, meanwhile, acute subgroups did not. Contralateral cerebellar hyperperfusion was also demonstrated in the chronic left infarction group. Using {sup 99m}Tc-ECD SPECT, we observed ipsilateral cerebral and contralateral cerebeller hyperperfusion in patients with cerebral infarction. However, whether these findings are related to the recovery of cerebral functions should be further evaluated.

  18. Effect of cerebral lymphatic block on cerebral morphology and cortical evoked potential in rats

    Institute of Scientific and Technical Information of China (English)

    Zuoli Xia; Baoling Sun; Mingfeng Yang; Dongmei Hu; Tong Zhao; Jingzhong Niu

    2006-01-01

    BACKGROUND: It has been shown that although brain does not contain lining endothelial lymphatic vessel,it has lymphatic drain.Anterior lymphatic vessel in brain tissue plays a key role in introducing brain interstitial fluid to lymphatic system;however,the significance of lymphatic drain and the affect on cerebral edema remains unclear.OBJECTIVE: To investigate the effect of cerebral lymphatic block on cerebral morphology and cortical evoked potential in rats.DESIGN: Randomized controlled animal study.SETTING: Institute of Cerebral Microcirulation of Taishan Medical College and Department of Neurology of Affiliated Hospital.MATERIALS:A total of 63 healthy adult male Wistar rats weighing 300-350 g were selected in this study.Forty-seven rats were used for the morphological observation induced by lymphatic drain and randomly divided into three groups:general observation group(n=12),light microscopic observation group(n=21)and electronic microscopic observation group(n=14).The rats in each group were divided into cerebral lymphatic block subgroup and sham-operation control subgroup.Sixteen rats were divided into cerebral the effect of cerebral lymphatic block on cortical evoked potential,in which the animals were randomly divided into sham-operation group(n=6)and cerebral lymphatic block group(n=10).METHODS:The experiment was carried out in the Institute of Cerebral Microcirculation of Taishan Medical College from January to August 2003.Rats in cerebral lymphatic block group were anesthetized and separated bilateral superficial and deep cervical lymph nodes under sterile condition. Superior and inferior boarders of lymph nodes were ligated the inputting and outputting channels, respectively, and then lymph node was removed so as to establish cerebral lymphatic drain disorder models. Rats in sham-operation control group were not ligated the lymphatic vessel and removed lymph nodes.and other operations were as the same as those in cerebral lymphatic block group

  19. Cerebral circulation and metabolism in cerebral infarction of middle cerebral artery territory

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF), oxygen metabolism (rCMRO2), oxygen extraction fraction (rOEF) and blood volume (rCBV) were measured with a high performance positron CT (HEADTOME-III) and the 15O labeled gas steady-state method. Seven normal volunteers and 13 patients with ischemic infarction located in the territory of unilateral middle cerebral artery (MCA) were subjected to the positron CT measurement. In the present study, over estimation of rOEF and rCMRO2 were corrected by rCBV using the principle described by Lammertsma and Jones. From these paremeters we also calculated an rCBV/rCBF which meant regional blood transient time of cerebral vessels (rTT). Early ischemic lesions showed two types of uncoupling between rCBF and rCMRO2. Patients studied within the 5th day of the onset showed high rOEF with low rCBF in the infarcted forcus (misery perfusion). About a week after onset rOEF was changed into low level with decreased rCMRO2 and recovered rCBF, and the change lasted to a month after onset recovered rCBF, and the change lasted to a month after onset (luxury perfusion). Then, about two months later, the lesions gradually went to matched change of rCBF and rCMRO2 (coupled perfusion). These changes of rCBF and rCMRO2 described above will reveal the natural course of ischemic brain tissue with acute onset. It was also proved that there was positive correlation between rTT and rOEF. A parameter of rTT will be important to presume rOEF from a single photon emission CT measurement, which has not been able to study oxygen metabolism but could measure rCBF and rCBV. The threshold levels of rCBF and rCMRO2 for morphological tissue damages assessed as a low density area on a X-ray CT were clinically estimated from the present study. The thresholds evaluated in patients within a day of onset, were 12 ml/100 ml/min, and 1.5 ml/ 100 ml/min for rCBF and rCMRO2, respectively. (J.P.N.)

  20. Intra Cerebral Hemorrhage Following Scorpion Sting

    OpenAIRE

    Mathur P C; Trikha Sushma; Kohli Ritesh

    2005-01-01

    Central nervous system manifestations following scorpion sting have been infrequently reported in literature. To emphasise the fact that this form of clinical presentation is not unusual we are reporting a case of scorpion sting associated with intra cerebral hemorrhage.