Cerebral haemodynamics in the elderly: the rotterdam study.

Transcranial Doppler ultrasonography allows the non-invasive assessment of cerebral haemodynamics. Data on the frequency distribution of these parameters in the oldest old are scarce, which makes a distinction between physiological and pathophysiological ageing difficult. We studied the relation between cerebral haemodynamic parameters and age and sex in 1,720 participants of a population-based study by means of transcranial Doppler ultrasonography. The end-diastolic, peak systolic and mean cerebral blood flow velocity, and cerebrovascular CO2 reactivity declined significantly with increasing age up to 90 years (per year -0.6 cm/s; -0.3 cm/s; -0.5 cm/s, and -0.6%/kPa, respectively). The pulsatility index increased with age (per year 0.01). End-diastolic, peak systolic and mean cerebral blood flow velocities were lower in men compared to women (age-adjusted difference 1.6 cm/s; 4.1 cm/s, and 2.5 cm/s, respectively). Cerebrovascular CO2 reactivity was higher in men compared to women. Adjusting for carotid atherosclerosis did not change the observed sex differences. These findings provide insight into physiologic changes of haemodynamics during ageing and may serve as a starting point for investigations on determinants of pathophysiologic changes in cerebral haemodynamics in the elderly.