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Vasomotor reactivity in dementia of alzheimer type

1994; Wiley; Volume: 9; Issue: 11 Linguagem: Inglês

10.1002/gps.930091108

1099-1166

Reinhard Heun, Volker Knappertz, And G. Krämer,

Functional Brain Connectivity Studies

Abstract The objective of this study was to examine the cerebral blood flow and the vasomotor function of CO 2 ‐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 CO 2 challenge. However, the excess reduction of the highest flow velocities measured during maximal CO 2 stimulation indicates that the number of small capillaries are diminished, or alternatively that the diameters of these capillaries are reduced in Alzheimer's disease.