OCULAR MOTOR DYSFUNCTION IN HIV-1-INFECTED SUBJECTS - A QUANTITATIVE OCULOGRAPHIC ANALYSIS

We recorded eye and head movements in 13 human immunodeficiency virus type-1 (HIV-1)-infected patients with CD4 counts of less than or equal to 500 cells/mm(3) using magnetic search coil oculography. Horizontal and vertical saccades, smooth pursuit, and vestibular smooth eye move ments were recorded, as were horizontal antisaccades and vestibular me mory-guided saccades. Rightward and leftward and upward and downward r esponses were analyzed separately. Compared to normal control subjects , HIV-1-infected patients performed the antisaccade test poorly, makin g the initial antisaccade in the correct direction (away from the targ et) in only 33% of trials. The mean final gaze position achieved durin g the vestibular memory-guided saccade task was less accurate for HIV- 1-infected patients than for control subjects, and this cor related wi th inaccuracies on the antisaccade task. Horizontal saccades, horizont al and vertical smooth pursuit, and vestibular smooth eye movements we re quantitatively normal. However, smooth pursuit showed directional a symmetries, vertically more than horizontally; horizontal and vertical unpredictable saccades were more inaccurate than predictable saccades ; and vertical saccade latencies were prolonged. In patients with HIV- 1 infection, abnormalities in vertical eye movements and relative asym metries in smooth pursuit gains, both horizontally and vertically, are more sensitive and consistent indicators of CNS dysfunction than are horizontal eye movement abnormalities or measurements of absolute smoo th pursuit gain and phase.