Neuropsychological characterization of the AIDS dementia complex and rationalization of a test battery.

OBJECTIVE

To define the neuropsychological deficits present in mild human immunodeficiency virus type 1 (HIV-1) associated with the acquired immunodeficiency syndrome (AIDS) dementia complex (ADC) and to develop a rational neuropsychological test battery for its diagnosis.

DESIGN

Survey.

SETTING

Subjects were recruited from large metropolitan hospital outpatient clinics and were all living independently in the general community.

PATIENTS: Three volunteer samples of homosexual-bisexual men: (1) 15 patients who met clinical and research criteria for mild ADC; (2) 27 HIV-seronegative (HIV-) controls; and (3) 17 patients with AIDS who were neurologically intact (NI-AIDS) who were matched with the ADC subjects by CD4 lymphocyte counts for severity of systemic HIV disease.

MAIN OUTCOME MEASURES: Neuropsychological test performance; z score comparisons were made with the HIV-control group using 2.25-SD cutoffs for abnormality.

RESULTS

Compared with NI-AIDS subjects, performance of patients with mild ADC was markedly worse in the cognitive areas of executive function, memory, and complex attention but not in affect or the cognitive areas of simple motor function, orientation, language, or visuospatial construction. Within the areas of executive function, memory, and complex attention, all of the HIV-controls and 95% of the NI-AIDS subjects had impaired test performance in a maximum of one area only. In marked contrast, 14 (93%) of the 15 patients with mild ADC had abnormal test performances in all three of these cognitive areas. Using a criterion of abnormal performance in at least two of the cognitive areas of executive function, memory, and complex attention, all patients with mild ADC could be differentiated from HIV-controls with 100% sensitivity and specificity and from NI-AIDS subjects matched for disease severity by CD4 lymphocyte count with 100% sensitivity and 94% specificity, which increased to 100% with the requirement of impairment in all three cognitive areas.

CONCLUSIONS

If time constraints or patient compliance limit neuropsychometric testing, examination to detect mild ADC first should be directed to the areas of executive function, memory, and complex attention. This pattern of neuropsychological deficits in patients with mild ADC is suggestive of subcortical dementia.