[Difficulties in the diagnosis of dementia]

We evaluated 125 ambulatory patients with a clinical syndrome of dementia. About half of them met criteria for diagnosis of Alzheimer's disease; vascular disorders and other etiologies were less prevalent. Among 176 patients with initially suspected Alzheimer's disease, this diagnosis was confirmed by clinical findings and follow up in 70%. Psychiatric disorders were responsible for the syndrome in 20%, other etiologies were less frequent. In the absence of specific markers for Alzheimer's disease this diagnosis should be established only after careful clinical studies and follow up. No clear limits between Alzheimer's disease and functional cerebral loss from aging can be defined at this time.