Age-related transcranial Doppler findings in the evaluation of cerebral circulation during postprandial and postural tests

We used transcranial Doppler (TCD) to investigate whether there are cerebra l circulation differences between young and elderly subjects in response to postprandial postural changes. Preprandial and postprandial systolic and d iastolic blood pressure, heart rate, mean middle cerebral artery (MCA) velo city (V-mean MCA), systolic/diastolic MCA velocity ratio (V-s/V-d MCA) and pulsatility index (PI) were determined in 15 healthy elderly subjects (mean age 74.3 +/- 6.5 years) and in 10 younger subjects (mean age 31.6 +/- 7.2 years) in the supine position and after a postural change. As compared with young subjects, elderly ones showed a greater postprandial systolic pressu re decline (p < 0.05) associated with a significant decrease of V-mean MCA (p < 0.05), and a greater increase of V-s/V-d and PI (p < 0.05 both). We co nclude that, as compared with young subjects, elderly ones have reduced cer ebrovascular adaptive response to pressure modifications induced by postpra ndial postural changes.