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Middle Cerebral (middle + cerebral)
Terms modified by Middle Cerebral Selected AbstractsCerebral vasomotor reactivity of bilateral severe carotid stenosis: is stroke unavoidable?EUROPEAN JOURNAL OF NEUROLOGY, Issue 2 2006A. Y. Gur We evaluated the cerebral hemodynamic features of severe bilateral carotid stenosis by assessing and comparing cerebral vasomotor reactivity (VMR) in the middle cerebral (MCA) and vertebral arteries (VA) by transcranial Doppler and the Diamox (1 g acetazolamide i.v.) test. VMR was evaluated by recording the percentage differences in peak systolic blood flow velocity in each MCA and VA at baseline and by the Diamox test. Twenty-eight symptomatic (SCAS) and 31 asymptomatic (ACAS) patients with bilateral severe (>70%) internal carotid artery stenosis were studied. The mean MCA VMR% was 29 ± 26.9% in SCAS and 43.2 ± 26.8% in ACAS patients (P < 0.01). Their respective mean VA VMR% was 30.2 ± 36.5% and 39.6 ± 24.4% (P = NS). VMR% of the symptomatic MCA side in SCAS patients was significantly lower than the opposite side (20.5 ± 31.1% and 39.2 ± 37.9% respectively; P < 0.03). In contrast, the VA VMR% of both sides in SCAS patients remained similar (28.1 ± 39.3% and 34.6 ± 47.9% respectively; P = NS). VMR% of the MCA and VA in ACAS patients was also similar for both sides of bilateral carotid stenosis. The cerebral hemodynamic features differ between SCAS and ACAS patients with bilateral carotid occlusive disease in the anterior part of the circle of Willis. An independent cerebral vascular reserve capacity of the posterior circulation is proposed. [source] Blood Flow Velocity and Pulsatility Index Differences in Patients With Unilateral MigraineHEADACHE, Issue 7 2001Oleg Y. Chernyshev MD Objective.,To evaluate blood flow velocity and pulsatility in unilateral migraine without aura during the headache-free period using transcranial Doppler (TCD) sonography. Methods.,Patients with unilateral headache were recruited during the headache-free period. Maximum mean flow velocity (MFV) and pulsatility index (PI) were measured in the middle cerebral (MCA) and basilar arteries. Controls were headache-free individuals without cerebrovascular disease. Results.,Twenty-five patients with right-sided migraine, 25 patients with left-sided migraine, and 19 controls were studied. The MCA PI was higher on the right headache side versus the left headache side (0.97 ± 0.2 versus 0.86 ± 0.1 cm/s, P = .02) and versus controls (0.9 ± 0.2 cm/s, NS). The basilar artery MFV was higher in patients with right-sided headache versus left-sided headache (39.5 ± 5.6 versus 34.7 ± 8.2 cm/s, P = .02) and versus controls (38.2 ± 8 cm/s, NS). No decrease in MFV with age was observed in patients with migraine. Conclusions.,Middle cerebral artery flow pulsatility and basilar artery velocity are higher in patients with right-sided migraine compared with left-sided migraineurs, during the headache-free period. Although these parameters were similar to controls, the differences found during the headache-free period in migraineurs may indicate vascular involvement predisposing to the unilateral headache recurrence. [source] External cephalic version induced fetal cerebral and umbilical blood flow changes are related to the amount of pressure exertedBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 5 2004Tak Yeung Leung Objective To correlate the applied pressure during external cephalic version with the changes in fetal middle cerebral arterial and umbilical arterial flow before and after the procedure. Design A prospective observational study over a two-year period. Setting External cephalic version was performed in a university hospital. Population Sixty-nine women with singleton breech-presenting pregnancy at or above 36 weeks of gestation undergoing external cephalic version. Methods During external cephalic version, the operator wore a pair of pressure-sensing gloves which had thin piezo-resistive sensors positioned on the palmar surface. During each version procedure, real-time pressure readings were recorded from all sensors, and then analysed with a computer program. The amount of pressure applied over time was presented by pressure,time integral. The pulsatility indices of both fetal middle cerebral artery and umbilical artery before and after external cephalic version were measured. The changes of pulsatility indices of both middle cerebral artery and umbilical artery were presented as a ratio of the post-external cephalic version pulsatility indices to pre-external cephalic version pulsatility indices, denoted by middle cerebral artery pulsatility index ratio and umbilical artery pulsatility index ratio, respectively. The statistical correlation between pressure,time integral and middle cerebral artery pulsatility index ratio and umbilical artery pulsatility index ratio are analysed using Pearson's correlation test. Main outcome measures Changes in pulsatility indices of fetal middle cerebral and umbilical arteries and fetal heart rate after external cephalic version. Results The overall success rate of external cephalic version was 77%. There was a significant negative correlation between pressure,time integral and both middle cerebral artery pulsatility index ratio (P= 0.001) and umbilical artery pulsatility index ratio (P= 0.012). When women were categorised according to placental site, pressure,time integral was negatively correlated with middle cerebral artery pulsatility index ratio only when the placenta was posteriorly located (P= 0.003), and with umbilical artery pulsatility index ratio only when the placenta was laterally located (P= 0.03). Conclusions The greater the force applied during external cephalic version, the greater the reduction in pulsatility indices of middle cerebral artery and umbilical artery, indicating an increase in blood flow through these arteries. The increase in cerebral blood flow after external cephalic version is more prominent when the placenta is lying posteriorly, while the increase in umbilical flow is more prominent when the placenta is lying laterally. These findings suggest that the vascular changes probably represent a direct effect of force exerted on the fetal head and the placenta. [source] Low cerebral blood flow velocity and head circumference in infants with severe hypoxic ischemic encephalopathy and poor outcomeACTA PAEDIATRICA, Issue 3 2009Pilvi Ilves Abstract Aims: To evaluate long-term changes in cerebral blood flow velocity (CBFV) and head circumference in asphyxiated infants. Methods: CBFV was measured in 83 asphyxiated and 115 healthy term infants in anterior and middle cerebral, basilar and internal carotid artery (ICA) up to the age of 60,149 days. The psychomotor development and head circumference was followed for 18 months. Results. Mean CBFV was increased (p < 0.05) during the first days after asphyxia in infants with severe hypoxic-ischemic encephalopathy (HIE) (n = 25) compared to control group or infants with mild to moderate HIE (n = 58) with maximum values found at the age of 36,71.9 h: in ICA (mean [95% CI]) 31.2 (25.5,36.6) cm/s in severe HIE infants compared to 13.0 (12.2,13.9) cm/s in controls. Decreased (p < 0.0001) mean CBFV developed in severe HIE infants by the age of 21,59 days: in ICA 14.1 (11.5,16.8) cm/s compared to 22.9 (21.4,24.4) cm/s in controls. Infants with severe HIE had similar mean height but lower head circumferences compared to controls (p < 0.05) at the age of 21,59 days. Conclusion: The high mean CBFV found in infants with severe HIE during the first days after asphyxia is temporary and low CBFV and head circumference develops by the age of 21,59 days. [source] | ||||||||||