Falling and postural deficits due to acute unilateral basal ganglia lesions
E. L. Labadie, G. I. Awerbuch, R. H. Hamilton and S. Z. Rapesak
University of Arizona Health Sciences Center, Tucson.
Nine patients presented with sudden falling events to one side while
sitting, standing, or walking. All were initially unaware of their severe
postural deficit, and five were obfuscated. The observed falls were a
distinctly slow, tilting motion in a stereotypic lateral or diagonal
trajectory, literally "like a falling log." The events occurred with eyes
opened and were exacerbated with eye closure, but no patient had evidence
of cerebellar, vestibular, or posterior column dysfunction or significant
motor weakness. Unilateral basal ganglia hemorrhages or lacunar infarcts
contralateral to the side of the fall were demonstrated by computed
tomographic scans. The overall prognosis was favorable; eight of nine
patients regained independent ambulation within 3 to 6 weeks. Our findings
indicate that a distinct loss of postural balance arises contralaterally to
unilateral pallidal-putaminal lesions.
