Arterial and Venous Cerebral Blood Flow Velocities in Healthy Volunteers

Transcranial Doppler ultrasound (TCD) enables assessment of brain hemodynamics through insonation of cerebral arteries and veins. Few studies have investigated whether the normal ranges of flow velocities in both arterial and venous compartments may be affected by age and sex.The purpose of this study was to determine the normal blood flow velocities across different sex and age subgroups in a cohort of healthy volunteers by studying the middle cerebral arteries (MCAs) and the straight sinus (SS).A total of 122 healthy volunteers undergoing preanesthetic assessment were recruited at Galliera Hospital in Genoa, Italy. The cohort was stratified for sex (males and females) and for age (18-44 years, 45-64 years, and ≥65 years). Data on systolic, diastolic, and mean flow velocities (FVs, FVd, and FVm, respectively) in the MCA and peak venous flow velocity in the SS (FVVs) were collected from each volunteer.The arterial FVs and FVm were significantly higher in males than in females; FVs, FVm, FVd, and FVVs increased across the age spectrum, especially in the elderly female population.Our findings suggest that there are differences in cerebrovascular flow velocities due to age and sex, which may be correlated to hormonal variations during the lifespan.