Focal cerebral hypoperfusion and selective cognitive deficit in dementia of the Alzheimer type.

Regional cerebral blood flow was investigated using single photon emission computed tomography and xenon-133 intravenous injection in six patients with dementia of the Alzheimer type (DAT) with atypical focal clinical presentation, and in 20 age-matched healthy volunteers. The patients had a progressive and preponderant cognitive deficit and a focal hypoperfusion that correlated with the neuropsychological findings, whereas the average flow did not significantly differ from that of controls. The assessment of concordant haemodynamic and neuropsychological focal abnormalities could be useful in the diagnosis of atypical cases of DAT.