Impairment of visuospatial function in idiopathic spasmodic torticollis.

We studied visuospatial function in 15 patients with idiopathic spasmodic torticollis (ST) and 15 age- and sex-matched controls. All subjects underwent a battery of visuospatial tests, assessing different functional components of spatial ability. The performance of ST patients on tasks of spatial perception did not significantly differ from that of normal subjects, but patients performed significantly worse on spatial tasks requiring mental manipulation of personal space. This distinct pattern of visuospatial impairment may result from basal ganglia dysfunction.