2000, Number 1
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ABSTRACTThe Single Photon Emission Tomography (SPECT) is one of the recent neuroimaging techniques that contributes with information about the regional cerebral blood flow (rCBF). The present paper presents a description of the SPECT methodology and reviews the contribution of cerebral SPECT studies in Alzheimer’s Disease (AD). Several studies have shown a pattern of bilateral parietotemporal hypoperfusion in AD. This pattern of rCBF enables to distinguish between AD and normal subjects with a sensibility of 70% to 100%, and a specificity of 87% to 100%. The SPECT is also a fundamental technique for the differential diagnosis for AD and other dementias like vascular dementia, Parkinson’s Disease, Huntington Disease and others. Several studies have shown an association between neuropsychological performance and rCBF, specially when studying patients with language impairments, apraxia, semantic memory impairments and attentional deficits. SPECT imaging studies conducted while the patient is engaged in a cognitive task or under sensory stimulation are referred to as activation studies. Activation studies afford unique opportunities to explore brain metabolic changes related to specific cognitive operations and to establish hypothesis of the neural networks supporting very discrete cognitive functions. We conclude that SPECT has the necessary potential to become a reliable diagnostic and research instrument for AD.
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