Comparative Study of Cerebral Ventricular Dilation and Cognitive Function in Patients with Alzheimer's Disease of Early versus Late Onset

Abstract

The clinical, psychological, and neurologic characteristics of 37 Japanese patients with early-onset Alzheimer's disease (eAD; onset before age 65 years) were compared with those of 23 patients with late-onset Alzheimer's disease (lAD; onset at age 65 years or later). This study evaluated brain atrophy using computed tomographic (CT) scans, and the behavioral and psychological differences in the two groups using the Gottfries-Bråne-Steen scale, Japanese revision (GBSS-JR). Follow-up CT scans were obtained and compared in 20 patients with eAD, 24 patients with lAD, and 23 elderly nondemented control subjects. The size of lateral cerebral ventricular dilation, measured every 6 months following admission, was significantly larger in the eAD patients than in the control subjects. The characteristics of the 37 patients with eAD were compared with those of the 23 patients with lAD by evaluating the scores on all 38 items in the five categories of the GBSS-JR. To compare the test results by duration of disease, patients were divided into subgroups according to average duration of disease: eAD1 (nine patients), 2.2 years; eAD2 (16 patients), 5.0 years; eAD3 (12 patients), 9.0 years; lAD1 (seven patients), 1.6 years; lAD2 (10 patients), 3.1 years; and lAD3 (six patients), 5.3 years. The GBSS-JR scores were compared in duration-matched pairs, that is, eAD1 versus lAD1 and eAD2 versus lAD3. The eAD1 patients showed significantly worse scores in four categories and 13 items compared with the lAD1 patients. Fewer differences in scores were found between eAD2 patients and the lAD3 patients than between the eAD1 patients and the lAD1 patients. Increasing severity of disease and rapid deterioration of patients with eAD, particularly during the first 3 years following disease onset, was recognized. The pattern of abnormalities on GBSS-JR showed no difference between the two broad groups (early versus late onset). The categorization of patients with Alzheimer's disease as early and late onset is relevant to clinical management.