AN ASSOCIATION OF HUMAN T-CELL LYMPHOTROPIC VIRUS TYPE-I INFECTION WITH VASCULAR DEMENTIA

Subjects ranging in age from 50 to 89 years old, either with or withou t dementia were studied by both ELISA for anti-human T-cell lymphotrop ic virus type I (HTLV-I) gag 100-130 antibody and by cranial CT in ord er to clarify the relationship between HTLV-I infection and dementia. The frequency of anti-HTLV-I antibody was found to be significantly hi gher in the patients with dementia (24/130, 18.5%) than in those witho ut dementia (11/139, 7.9%) (P=0.0169). Among the various types of deme ntia, HTLV-I seropositivity was found to be significantly associated w ith vascular dementia (11/48, 23%) (P=0.0087), but not with Alzheimer type dementia. In addition, HTLV-I seropositivity was also associated with Babinski sign, and the severity of cerebral infarction, ventricul ar dilatation and periventricular lucency on CT. The presence of HTLV- I therefore appears to be one of the risk factors for vascular dementi a in HTLV-I endemic areas.