Contribution of vision to the stabilization of body sway in patients with spinocerebellar degeneration.

Body sway was recorded with closed eyes, open eyes and visual feedback for 30 s each. Thirteen patients with spinocerebellar degeneration and 17 age-matched normal controls underwent the examination. Four parameters (area, length, sums of frequency spectrum in the anterior-posterior and lateral directions) were computed. Furthermore, Romberg ratios between closed and open eye conditions [Romberg c/o] and Romberg ratios between closed eyes and visual feedback conditions [Romberg c/f] were computed. Four parameters were significantly greater in the patients with spinocerebellar degeneration than in the normal controls. However, three of eight Romberg ratios were significantly greater in the patients with spinocerebellar degeneration than in the normal controls. The results implied that the proprioceptive-posture loop was mainly disordered while the visuo-postural loop was intact in patients with spinocerebellar degeneration.