Acetazolamide Vasoreactivity in Vascular Dementia: A Positron Emission Tomographic Study

Abstract

The present study investigates the vasoreactivity of the brain in patients with large infarcts and dementia (multi-infarct dementia; MID) and in patients with microangiopathy, lacunes, white matter changes and dementia (lacunar dementia; LD) using positron emission tomography (PET) and ¹³NH₃ as regional cerebral blood flow (rCBF) tracer. In the control group, an increase in rCBF ranging from 32 to 43% was found in all brain regions after intravenous acetazolamide administration. In both the MID group and the group with multiple infarcts without dementia, moderate loss of vasoreactivity was observed in the frontal, temporal and parietal cortex compared to the control values. Vasoreactivity was severely impaired in all cerebral regions of the LD group and restricted to the thalamus in the group with lacunes and white matter changes without dementia (lacunar stroke; LS). This suggests that global loss of vasoreactivity is not a determining factor in the occurrence of MID, but might be important in LD. The present study shows that loss of the vascular reserve leading to exhausted metabolic reserve of the whole brain is one of the possible mechanisms for the occurrence of vascular dementia.

Simultaneous Measurement of Arterial Transit Time, Arterial Blood Volume, and Cerebral Blood Flow Using Arterial Spin-Labeling in Patients with Alzheimer Disease

“…For example, Nagata et al 5 measured MTT and VR to carbon dioxide inhalation in patients with AD and VD and found that MTT was prolonged and VR was depressed in patients with VD, whereas the 2 indices were preserved in patients with AD. 5 Impairment in the responsiveness to vascular activation in VD was reported by De Reuck et al, 15 whereas other groups found no such impairment in AD based on SPECT [16][17][18] and xenon-enhanced CT 19 analysis. Moreover, Puls et al 20 revealed, by using transcranial sonography, that tissue transit time is prolonged in VD but not in degenerative dementia.…”

A Systematic Review of Dynamic Cerebral and Peripheral Endothelial Function in Lacunar Stroke Versus Controls

“…Hand-searching identified 3 additional publications. Of the 30 for full text reading, 3 were excluded (unable to translate: Russian 16 and Slovakian 17,18 ) and 11 failed to meet the inclusion criteria (no control subjects, 19,20 not assessing dynamic endothelial function, or inappropriate patients [21][22][23][24][25][26][27][28][29] ). Therefore, 16 papers were eligible, including 974 individuals.…”

Development and Progression of Leukoaraiosis in Patients With Brain Ischemia and Carotid Artery Disease

“…Lacunar strokes were defined by criteria of classic lacunar syndromes, with or without radiological deep lesions no more than 1 cm in diameter. 7 Cardioembolic strokes were defined by a combination of clinical and echocardiographic criteria. Ischemic strokes without a lacunar or cardioembolic origin were classified as large-artery strokes.…”

“…The mechanism is not considered to be chronic low perfusion as cerebral blood flow in affected areas lies within normal limits at rest or is modestly decreased in proportion to tissue loss. There is, however, clear evidence of diminished perfusion reserve, 6,7 and it is hypothesized that episodic mild ischemia occurs as a result of intermittent changes in cerebral perfusion pressure. The process has been termed "incomplete infarction."…”