Declining incidence of AIDS dementia complex after introduction of zidovudine treatment.

OBJECTIVE

To assess the incidence of the AIDS dementia complex and the presence of HIV I p24 antigen in cerebrospinal fluid in relation to zidovudine treatment.

DESIGN

Retrospective study of a consecutive series of patients with AIDS from 1982 to 1988.

SETTING

An academic centre for AIDS.

PATIENTS

196 Patients with AIDS and neurological symptoms examined from 1982 to 1988.

INTERVENTIONS

Zidovudine treatment, which was introduced to The Netherlands on 1 May 1987 for patients with severe symptoms of HIV infection (Centers for Disease Control groups IVA, B, C, and D).

MAIN OUTCOME MEASURES

Diagnosis of AIDS dementia complex and presence of HIV I p24 antigen in cerebrospinal fluid.

RESULTS

The AIDS dementia complex was diagnosed in 40 of the 196 (20%) patients with AIDS. Thirty eight of 107 patients with AIDS (36%) not taking zidovudine developed the AIDS dementia complex compared with two of the 89 (2%) taking the drug (p less than 0.00001). The incidence of the AIDS dementia complex increased to 53% in the first half of 1987, after the introduction of zidovudine in May 1987, decreasing to 10% in the second half of 1987 and to 3% in 1988. Dementia was diagnosed before definition of the AIDS dementia complex (1986) according to DSM-III criteria and there was good agreement between diagnosis before and after 1986. Sixteen of 61 samples of cerebrospinal fluid (26%) from patients with AIDS (10 with the AIDS dementia complex) not taking zidovudine were positive for HIV I p24 antigen, whereas none of 37 cerebrospinal fluid samples from patients with AIDS (two with the AIDS dementia complex) taking zidovudine were positive.

CONCLUSIONS

The incidence of AIDS dementia complex in patients with AIDS declined after the introduction of systematic treatment with zidovudine; the AIDS dementia complex might be prevented by inhibiting viral replication in the central nervous system.