HIV-specific changes in the motor performance of HIV-positive intravenous drug abusers.

Motor tests comprising the analysis of postural tremor, most rapid voluntary alternating index finger movements (MRAM) and the rise time of most rapid index finger extensions (CT) allow us to quantify HIV-associated minor motor deficits electrophysiologically. The electrophysiological results in 57 HIV-positive individuals who acquired HIV infection by intravenous drug abuse (IVDA) were compared with those of 57 matched HIV-positive homosexuals and 98 HIV-negative controls to evaluate a possible additional influence of IVDA on motor performance. Motor deficits showed no differences between HIV-positive i.v. drug abusers and homosexuals, revealing a highly significant slowing of MRAM and prolongation of CT to an almost identical extent. Thus, in HIV-infected individuals minor motor deficits are characteristic early signs of subclinical central nervous system involvement regardless of the mode of HIV infection.