In a prospective study to determine the incidence of clinical dementia
in patients with AIDS and ARC, 29 men and 3 women, 19 with ARC and 13 with
AIDS, were examined neurologically and neuropsychologically every 6 months
for 2 years during a placebo-controlled zidovudine (AZT) licensing trial.
Most received two MRI brain scans. Although no patient was clinically
demented at baseline, 9 (28%) developed dementia during the 2 years.
Progression to dementia was associated with neuropsychological
deterioration and with worsening on MRI during a preceding 6-month period,
but not with baseline treatment group assignment. The results suggest that
patients at CDC Stage IV who do not receive antiretroviral treatment
earlier in their illness may develop clinical dementia at an annual rate of