Analysis of body sway in patients with cerebellar lesions.

By using the body sway test, we compared patients with the cerebellar type of spinocerebellar degeneration and with cerebellar hemisphere lesion with normal controls. In the X-direction, the Y-direction, the XY-direction, and the area, the patients with both spinocerebellar degeneration and with cerebellar hemisphere lesion swayed more than the normal controls either with eyes open or closed. In non-sequential 8-vector analysis the patients with spino-cerebellar degeneration swayed forward and backward, while the patients with cerebellar hemisphere lesion swayed right and left, especially with eyes closed. In the patients with the cerebellar type of spinocerebellar degeneration, the vermis atrophy was particularly noticeable. The patients with cerebellar lesions swayed with eyes open just as much as normal controls with eyes closed and did not sway greatly with eyes open. We concluded that the visual input plays an important role in the compensation for postural imbalance in the patients with cerebellar lesions and that the cerebellar hemisphere regulated the sway to right and left, while the vermis regulated the sway forward and backward in an upright standing posture.