Only a limited number of transcranial color-coded Doppler studies have provided ranges for the normal reference values of cerebral hemodynamic parameters. These reports are not fully convergent in relation to the range of values or to the age and sex dependence of blood flow parameters. The aim of the present study was to provide data regarding normal reference ranges.We examined 182 healthy volunteers (79 men and 103 women; age range, 20-86 years old) with color-coded Doppler sonography via a temporal acoustic window with a 2.5-MHz transcranial probe. The subjects were divided into three age groups: 20-40 years old (group 1), 41-60 years old (group 2), and more than 60 years old (group 3). Angle-corrected peak systolic, end-diastolic, and mean velocities as well as impedance indexes were determined in anterior, middle, and posterior cerebral arteries.Mean velocity values for middle, anterior, and posterior cerebral arteries in age group 1 were 81+/-20, 56+/-14, and 52+/-12 cm/sec (mean +/- SD), respectiv...

This study is the first report on human intracranial temperature in conscious patients during and after an upper respiratory bypass. Temperatures were measured in four subjects subdurally between the frontal lobes and cribriform plate (T_cr) and on the vault of the skull (T_sd). Further measurements were taken in the esophagus (T_es) and on the tympanic membrane. Reinstitution of airflow in the upper respiratory tract under conditions of mild hyperthermia gave a rapid drop in T_cr of 0.4–0.8°C. In three patients the intracranial temperature at the basal aspect of the frontal lobes fell below T_es. Thus local selective cooling of the brain surface below that of the trunk temperature was shown to occur. Intensive breathing by the patients after extubation for a 3-min period produced a cooling at the site of T_cr measurement at a rate of up to 0.1°C/min, and this response could be evoked on demand. The results support the view that cooling of the upper airway can directly influence human brain temperature.

Dietary habits and adequate dietary intake of antioxidants in the diet may be one of the most important environmental factors for the prevention of Multiple Sclerosis (MS).

To prospectively determine the accuracy of transcranial color-coded duplex ultrasonography (US) used alone and in conjunction with carotid artery US for diagnosis of middle cerebral artery (MCA) spasm, with intraarterial digital subtraction angiography (DSA) used as the reference standard. The institutional ethics committee approved the study. Each patient, or members of the patient's family, gave informed consent. One hundred twenty consecutive patients (64 women, 56 men; mean age, 45.5 years +/- 13.6 [standard deviation]) were routinely referred for DSA after subarachnoid hemorrhage. Vasospasm was graded as mild (< or =25% reduction in vessel diameter), moderate (>25% to 50% reduction), or severe (>50% reduction). US was performed 2 hours or less before angiography. The ratio of flow velocity in the middle cerebral artery (V(MCA)) to flow velocity in the ipsilateral extracranial internal carotid artery (V(ICA)) was calculated. Diagnostic accuracy was evaluated by calculating the area under the receiver operating characteristic curve (Az). The significance of the difference between the two Az values (for US vs DSA) was determined by using the z test with correction for correlated data. Nine of 120 patients were excluded because of inadequacy of acoustic windows in the squama of temporal bones. Spasm was mild in 17, moderate in 16, and severe in only nine of 222 arteries studied. Arteries with moderate or severe vasospasm were combined in one group. The best-performing parameters were peak systolic velocity and V(MCA)/V(ICA) ratio. Az values for these two parameters in diagnosis of moderate-to-severe vasospasm were 0.93 and 0.95, and in diagnosis of mild vasospasm, 0.90 and 0.91. Accuracy of the V(MCA)/V(ICA) ratio calculated on the basis of end-diastolic velocity for diagnosis of mild MCA narrowing was significantly better than that of end-diastolic MCA velocity alone (Az = 0.88 vs 0.84, P < .05). The stepwise approach with use of the V(MCA)/V(ICA) ratio after flow velocity measurements in the MCA resulted in a decreased number of false-negative findings in both vasospasm subgroups. The thresholds of highest efficiency were at a mean velocity of 94 and 108 cm/sec and a peak systolic V(MCA)/V(ICA) ratio of 3.6 and 3.9 for diagnosis of mild and moderate-to-severe vasospasm, respectively. Transcranial color-coded duplex US alone or in conjunction with carotid artery US has excellent accuracy for angiographic detection of vasospasm. Use of MCA velocity measurements and V(MCA)/V(ICA) ratio can increase the accuracy of Doppler US.

Meningiomas constitute up to 13% of all intracranial tumors. The predictive factors for meningioma have not been unambiguously defined; however some limited data suggest that the expression of matrix metalloproteinases (MMPs) and vascular endothelial growth factor (VEGF) may be associated with the presence of peritumoral brain edema (PTBE) and worse clinical outcome. The aim of this study was to analyze the expressions of MMP-9 and VEGF in a group of meningiomas of various grades and to study associations between these two markers and PTBE. The study included patients with supratentorial meningiomas. The patients were divided into low- (G1) and high-grade meningiomas (G2 and G3). PTBE was assessed on MRI. The expressions of VEGF and MMP-9 were determined immunohistochemically. The expression of MMP-9 was observed significantly more often in G3 meningiomas than in lower grade tumors. The presence of stage II or III PTBE was associated with a significant increase in MMP-9 expression. The expression of VEGF did not differ across the PTBE stages. Our findings point to a significant role of MMP-9 and VEGF in the pathogenesis of peritumoral brain edema in low- and high-grade meningiomas.