Regional cerebral blood flow (rCBF) was assessed in 35 patients with possible or probable Alzheimer's disease (AD) and in 16 patients known to have had at least one stroke. Patients were evaluated before and after the administration of 1 g acetazolamide (ACZ) by means of a rotating four-detector single-photon emission computed tomograph (SPECT) and inhaled Xe-133. RCBF values in mL/minute/100 g were derived from eight cortical regions of interest (ROI), and from the whole transverse section as a measure of whole brain flow (WBF). ROI/WBF ratios were calculated for each ROI in paired determinations done before and 15 minutes after the administration of ACZ. Results were compared with those previously obtained in a study of 15 normal, healthy volunteer subjects. ROI/WBF ratios >2 standard deviations (SD) below the mean for a given ROI in the normal group were regarded as probably abnormal, whereas ratios >4 SD below the mean were considered definitely abnormal. After ACZ administration, the number of ROI >2 SD below the normal mean decreased significantly in the AD group and was unchanged in the stroke patients. However, the number of ROI/WBF ratios >4 SD below the normal mean fell in the AD group and rose in the stroke group, with the difference in behavior highly statistically significant. Thus, the response of low-flow areas in ACZ differs in AD and in stroke, which could be of ultimate diagnostic significance.
- Acetazolamide (Diamox) test for vasoreactivity
- Alzheimer’s disease
- Brain blood flow
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging