NEUROPHYSIOLOGICAL ASSESSMENT OF PERIPHERAL-NERVE AND SPINAL-CORD FUNCTION IN ASYMPTOMATIC HIV-1 INFECTION - RESULTS FROM THE UCMSM MEDICAL-RESEARCH-COUNCIL NEUROLOGY COHORT

As part of the Medical Research Council prospective study of the neuro logical complications of HIV infection, neurophysiological tests of sp inal cord and peripheral nerve function were recorded in a cohort of h omosexual or bisexual men. The studies included motor and sensory nerv e conduction studies, vibration perception thresholds, somatosensory e voked potentials and motor evoked potentials elicited by magnetic stim ulation. The results were compared with markers of immune function. Th e findings from 114 volunteers were analysed in a cross-sectional stud y. Fifty-nine were HIV-seropositive but asymptomatic, 26 had progresse d to the symptomatic stages of HIV disease and 29 were persistently HI V-seronegative. There was some evidence of a mild sensory axonopathy i n the symptomatic HIV-seropositive group, No differences were detected between the asymptomatic HIV-seropositive group and the HIV-seronegat ive comparison group. There were no consistently significant correlati ons between the neurophysiological measurements and CD4 counts and bet a(2) microglobulin levels. On repeated testing, there was no evidence of a trend towards deterioration over a mean period of approximately 3 years in 36 HIV-seropositive subjects who remained asymptomatic compa red with 22 HIV-seronegatives. These findings have failed to demonstra te neurophysiological evidence of spinal cord or peripheral nerve dysf unction in the asymptomatic stages of HIV infection.