Alzheimer's Disease in Down's Syndrome: Visual Retention Deficits

Forty hospitalized adult subjects participated in a study employing delayed-matching-to-sample performance as a measure of visual short-term retention. Aging patients with Down's syndrome made significantly more errors than two control groups of younger patients with Down's syndrome and two control groups of age-matched retarded patients without Down's anomaly. The results indicate that the early signs of Alzheimer's disease can be detected in aging patients with an underlying primary amentia of Down's syndrome. It was suggested that the early course of the disease may be the same both in individuals of normal intellect who develop Alzheimer's disease and in persons with Down's syndrome, all of whom can be expected to develop the disease in later life. It was further suggested that the underlying brain mechanisms controlling higher functions such as memory may be similarly altered in both types of patients.