Normal Blood Flow Velocities of Basal Cerebral Arteries Decrease with Advancing Age: A Transcranial Doppler Sonography Study

Abstract

Transcranial Doppler sonography (TCD) is a non-invasive diagnostic tool enabling evaluation of blood fl ow characteristics of basal intracerebral vessels via thin calvarian regions. Several factors may affect the normal values of cerebral hemodynamic parameters, and standard reference values for each laboratory are needed for precise interpretation of the results. The aims of this study were to determine normal values of fl ow velocities of basal cerebral arteries of our TCD laboratory, and to study the infl uence of age and gender on normal values. We studied 63 healthy volunteers (30 male and 33 females; age range, 5 -69 years old) with TCD with a 2-MHz transcranial probe. The subjects were divided into 7 age groups: 5-10 years, 11-20 years, 21-30 years, 31-40 years, 41-50 years, 51-60 years and > 60 years. Mean velocity (V mean), peak systolic velocity (PSV), and end-diastolic velocities (EDV) were determined in middle, anterior and posterior cerebral arteries. No signifi cant gender difference was found. However, there was a decrease in blood fl ow velocities in all vessels with advancing age, which was signifi cant when subjects older than 40 years and 40 years old were compared. V mean, PSV and EDV values were highest in the age group of 5 -10 years old and lowest in volunteers older than the age of 60 ( p < 0.05). As a conclusion, fl ow velocities in basal cerebral arteries range widely and are signifi cantly age-related. Age matching of TCD data is a requirement for clinically relevant conclusions.transcranial Doppler sonography; basal; cerebral arteries; normal values; healthy subjects. Tohoku

The correlation between lateralization of intracerebral hemorrhage in basal ganglia and handedness

“…The mean blood flow velocities were relatively higher in the left ACA of 20 right-handed subjects, and 74 right-handed subjects showed the opposite. Twenty four subjects were excluded for the same blood flow velocities on both sides, eight subjects were excluded due to the failure of detecting the blood flow, and 15 subjects were excluded for the abnormal blood flow velocities on one or both sides 8 .…”

Age, aerobic fitness, and cerebral perfusion during exercise: role of carbon dioxide

“…Compared with young healthy individuals a reduced CBF (24) and MCAv mean has consistently been reported in the aged population both at rest (2,7,9,15,25,27,49) and during exercise (9,10,28,32). Although a reduced MCAv mean response in aged humans is observed with exercise, its pattern follows that of young individuals, i.e., an initial increase which is then followed by a decline as the exercise intensity becomes intense (9,10,28,32).…”

“…In young healthy individuals this drop in cerebral perfusion is likely the consequence of a hyperventilation facilitated reduction in PaCO 2 and hence augmented cerebral vasoconstriction (39). Accordingly, administration of CO 2 to the inspired air during exercise abolishes the decrease in MCAv mean (44,45), and during vigorous exercise MCAv mean is regulated by PaCO 2 and only to a lesser extent influenced by cerebral metabolism, mean arterial pressure (MAP), cardiac output, or sympathetic nerve activity (35).Compared with young healthy individuals a reduced CBF (24) and MCAv mean has consistently been reported in the aged population both at rest (2,7,9,15,25,27,49) and during exercise (9,10,28,32). Although a reduced MCAv mean response in aged humans is observed with exercise, its pattern follows that of young individuals, i.e., an initial increase which is then followed by a decline as the exercise intensity becomes intense (9,10,28,32).…”

Cerebral blood flow and cerebrovascular reactivity at rest and during sub-maximal exercise: Effect of age and 12-week exercise training

“…Global CBF declines gradually with ageing, by 25-30 % between 20 and 80 years of age (Ainslie et al 2008;Buijs et al 1998;Demirkaya et al 2008;Krejza et al 1999;Liu et al 2011) or~5 % per decade (Grolimund and Seiler 1988). The effect of healthy ageing on cerebrovascular CO2 reactivity is less clear, however.…”