SPECT FOR DIFFERENTIAL-DIAGNOSIS OF DEMENTIA AND CORRELATION OF RCBF WITH COGNITIVE IMPAIRMENT

Tc-99m-HM-PAO single photon emission computed tomography (SPECT) was u sed to image 30 patients referred for the assessment of dementia. SPEC T images revealed various patterns of regional cerebral perfusion (rCB F) in the subgroups of patients with the clinical diagnoses of Alzheim er's disease (AD, n = 14), Pick's disease (n = 1), and multi-infarct d ementia (n = 7). In three patients, SPECT clarified the clinical diffe rential diagnostic possibilities. Using a relative rCBF quantification technique, the relationship between specific cognitive impairments an d rCBF in the AD patients was determined. There was a significant corr elation between language impairment and left hemisphere hypoperfusion, whereas, apraxia correlated with hypoperfusion in the left parietal r egion. Thus, HMPAO SPECT is useful as an aid in the differential diagn osis of dementia and the technique of relative rCBF quantification wit h SPECT may contribute to the understanding of the clinico-anatomical relations of cognitive deficits in dementia.