NEUROPSYCHOLOGICAL TESTS AND [TC-99M]-HM PAO SPECT IN THE DIAGNOSIS OF ALZHEIMERS DEMENTIA

Twenty-three patients with Alzheimer's dementia (AD) in relatively ear ly stages and 40 patients with other cognitive disorders of vascular o r degenerative aetiology underwent neuropsychological examination and [Tc-99m]-HM PAO single photon emission computed tomography (SPECT). In contrast to the commonly accepted notion of a posterior temporopariet al reduction of tracer uptake as the typical SPECT pattern of AD, the most consistent feature found in the SPECT images of our AD patients w as a hippocampal uptake deficit, associated with a variable degree of temporal, parietal and frontal deficit (extending from the posterior t o the anterior regions), according to the severity of the disease. The se results support the theory of AD as a ''hippocampal dementia'', at least in the early stages. Neuropsychological tests were found to be s omewhat more specific and more accurate than SPECT in distinguishing A D from non-AD cases.