Postural imbalance: an early sign in HIV-1 infected patients.

We have recorded postural performance in 50 HIV-infected patients in different stages of the disease (Walter Reed (WR) stages I-VI) by means of a force measuring platform. The results were compared with 50 age-matched controls. A significant instability was particularly evident when standing on an unstable foot support. In patients standing with "eyes closed", postural sway was significantly higher in every patient group (WR I-II: P less than 0.02, WR III-V: P less than 0.001, WR VI: P less than 0.001). Patients in stage WR I-II showed no relevant neurological abnormalities. In agreement with other neurophysiological data in the literature we suggest that postural imbalance could be an early sign of central nervous system penetration of HIV. No correlation with electromyographic or cerebrospinal fluid findings could be found.