Relatively higher norms of blood flow velocity of major intracranial arteries in North-West Iran

Abstract

BackgroundTranscranial Doppler (TCD) is a noninvasive, less expensive and harmless hemodynamic study of main intracranial arteries. The aim of this study was to assess normal population values of cerebral blood flow velocity and its variation over age and gender in a given population.FindingsEighty healthy volunteers including 40 people with an age range of 25-40 years (group1) and 40 persons with an age range of 41-55 years (group2) were studied. In each group 20 males and 20 females were enrolled. Peak systolic, end diastolic and mean velocities of nine main intracranial arteries were determined using TCD. Mean age of the studied volunteers was 31.6 ± 4.50 years in group one and 47.2 ± 4.3 years in group two. Mean age among males was 40 years and among females it was 39. Mean blood flow velocity in middle, anterior and posterior cerebral arteries, vertebral and basilar arteries was 60 ± 8, 52 ± 9, 42 ± 6, 39 ± 8 and 48 ± 8 cm/sec respectively. Cerebral blood flow velocities among females were relatively higher than males. Cerebral blood flow velocity of left side was relatively higher than right side.ConclusionCompared to previous studies, cerebral blood flow velocity in this population was relatively higher.

Transcranial Doppler Velocities in a Large, Healthy Population

“…Our findings were similar to the general trends found in most other studies, 18‐28 although some authors found no association between age and cerebral blood flow velocities 29‐31 . The variations in MBFV by age may be because of decreased metabolic demands, higher hematocrit, or changes in the cerebrovascular hemodynamics during the aging process, and changes of cerebral autoregulation with age as a result of the accumulation of vascular risk factor burden and autonomic abnormalities 32 .…”

“…Our study did not show any significant differences in MFBV from dominant to nondominant side based on handedness. Higher velocities on the left have been reported by others, 22,30,31 because of the dominance of the left hemisphere or lack of adequate rest between stimulation of the patient and initiation of the exam. The greater variability in cerebral blood flow velocities on the left side of the Circle of Willis may explain the lack of hemispheric differences of velocities in our study.…”

“…Women have been shown to have higher MBFV than men in some, 20,31‐34 but not in other studies 19,28 . These differences are thought to be because of the differences in hematocrit, which may be higher in men, and estrogen fluctuations in women 35‐36 .…”

“…Our findings were similar to the general trends found in most other studies, [18][19][20][21][22][23][24][25][26][27][28] although some authors found no association between age and cerebral blood flow velocities. [29][30][31] The variations in MBFV by age may be because of decreased metabolic demands, higher hematocrit, or changes in the cerebrovascular hemodynamics during the aging process, and changes of cerebral autoregulation with age as a result of the accumulation of vascular risk factor burden and autonomic abnormalities. 32 Increased incidence of cardiac disease, stiffening of the large proximal arteries, or the intracranial vessels, and reduced cardiac output may also be important factors for reduced mean flow velocities and increased PI in the older population.…”

Doppler study of cerebral arteries in hypercholesterolemia

“…The standard method of using a 2 mHz probe for the intracranial arteries and a 4 mHz probe for the cervical carotids was applied in the present study. The Doppler signals were detected through the temporal window for the middle cerebral artery, anterior cerebral artery and two segments of the posterior cranial artery (PCA 1 , PCA 2 ), through the suboccipital window for the vertebral arteries and basilar artery, and through the cervical window for the internal carotid arteries 14. Mean blood flow velocity, pulsatility index, and resistance index were recorded in all the arteries 15–17…”