6533b836fe1ef96bd12a11a0

RESEARCH PRODUCT

Vasomotor reactivity in dementia of alzheimer type

subject

description

The objective of this study was to examine the cerebral blood flow and the vasomotor function of CO2-responsive intracerebral vessels in Alzheimer's disease. Patients met DSM-III-R criteria for dementia of Alzheimer type and had neither symptoms nor signs of cardiovascular or cerebrovascular disease. Blood flow velocities in both middle cerebral arteries (MCA) were recorded using transcranial Doppler sonography during hypercapnia, normocapnia and hypocapnia. Several psychometric tests were performed. Patients' age, disease duration and severity of dementia did not correlate with vasomotor reactivity. Exploratory analysis revealed that mean flow velocities under hypercapnia correlated with severity of dementia and with patient's age. This suggests that the disease process does not influence the autoregulative function of small resistance vessels as assessed by CO2 challenge. However, the excess reduction of the highest flow velocities measured during maximal CO2 stimulation indicates that the number of small capillaries are diminished, or alternatively that the diameters of these capillaries are reduced in Alzheimer's disease.