Decreased homovanilic acid in cerebrospinal fluid correlates with impaired neuropsychologic function in HIV-1-infected patients

To determine whether dopamine metabolism is abnormal in HIV infected patients and whether dopamine metabolism abnormalities are related to specific neuropsychologic characteristics in HIV-infected patients, we measured cerebrospinal fluid (CSF) levels of homovanilic acid (HVA), the primary dopamine metabolite, in 10 HIV-infected patients and compared it to HVA levels in CSF in a group of 13 healthy control subjects. HIV-infected patients were also assessed with a battery of neuropsychologic tests and HVA levels were then correlated with performance on specific neuropsychologic tests. The mean (+/-SD) HVA level in CSF was 100.9 +/- 29.3 nmol/L in the HIV-infected study group and 230.5 +/- 50.0 nmol/L in the non-HIV-infected control group (p < 0.0001). The decrease in concentrations of HVA in CSF correlated with impairment on performance on neuropsychologic testing (Spearman r = 0.67; p = 0.03). When the relationship between HVA levels and specific cognitive domains was evaluated, we observed trends for positive correlation between HVA levels and tests that measure motor speed (r = 0.59; p = 0.074) and those testing attention, concentration, and executive control (r = 0.54; p = 0.108). There was no relationship between performance on memory tests and CSF HVA levels (r = -0.0061; p = 0.987). These results further support the hypothesis that dopaminergic dysfunction plays an important role in the pathogenesis of AIDS dementia complex (ADC) and suggest that specific motor and cognitive abnormalities may be related to depressed dopaminergic activity. This may have important implications for the development of treatments or preventive strategies for ADC.