Methods for detecting early signs of AIDS dementia complex in asymptomatic HIV-1-infected subjects

To determine the optimal diagnostic procedures for identifying early signs of AIDS dementia complex (ADC) in asymptomatic HIV-1-infected individuals, in order to prevent further cognitive function impairment by early treatment.

Study patients had been referred electively and consecutively to hospital; all had been referred for the first time and gave informed consent. Inclusion criteria were (1) lack of history and/or symptoms of psychosis and neurological disorders; (2) lack of active viral, protozoan or fungal pathology; (3) abstinence from heroin and/or cocaine for at least 6 months before baseline evaluation.

Subjects were seen at the L. Spallanzani Hospital for Infectious Diseases, Rome, Italy between March 1989 and March 1991.

Eighty-two asymptomatic HIV-1-infected subjects: 41 drug users, 27 homosexuals and 14 heterosexuals.

All subjects were evaluated using Wechsler-Bellevue I, Benton C form and Bender tests. Thirty-nine subjects underwent single-photon emission computed tomography (SPECT) and 12 magnetic resonance imaging (MRI). The immunological status of each subject was determined.

On psychometric testing, 23 out of the 82 (28%) asymptomatic subjects had a mental decay percentage (MD%) > or = 20%. Cerebral perfusion abnormalities were detected in 31 out of 39 (79.48%) subjects who underwent SPECT; MRI abnormalities were observed in seven out of 12 (58%) subjects. Twelve out of 23 subjects with MD% > or = 20, 15 out of 29 subjects with SPECT abnormalities and four out of seven patients with MRI abnormalities had total CD4+ lymphocyte counts > or = 500 x 10(6)/l.

The high incidence of abnormal SPECT and of MD% > or = 20 in asymptomatic HIV-1-infected patients, and the lack of correlation between immunological status and degree of mental decay, SPECT and MRI abnormalities raise many questions about subclinical HIV-1 neurological disease.