Effect of thalamotomy and levodopa therapy on the speech of Parkinson patients.

The speech of three groups of Parkinson patients--nonsurgical, postunilateral and postbilateral thalamotomy--was evaluated. Dysarthria, bulbar motility and pyramidal tract indexes were determined for each patient. There was a statistically significant greater impairment in dysarthria and pyramidal tract indexes of patients with thalamotomy. L-Dopa and carbidopa therapy failed to significantly improve speech in any group.