Stereotaxic thalamotomy for treatment of posttraumatic movement disorders.

Stereotaxic ventrolateral thalamotomies have been successful in treating a wide spectrum of involuntary movement disorders, but very little has been reported concerning their use in posttraumatic movement disorders (MD's). This procedure has been used to treat 11 patients who developed persistent MD following severe closed head injuries. Among these, seven had action tremors, nine hemiballismic movements, two choreoathetoid movements, and two truncal ataxia. In two patients the MD was significant bilaterally, and in eight patients more than one type of MD was present. Standard thermal lesions based on the middle anterior commissure-posterior commissure line, 10 to 15 mm lateral to the midline, were performed following stimulation. Within the immediate postoperative period, all 11 patients had some degree of improvement in their MD; five showed marked improvement, four moderate improvement, and two minor improvement. One patient had recurrence of the MD 24 hours postoperatively requiring a second procedure, with marked improvement subsequently. In five of the six patients who underwent a left-sided procedure, a transient increase in preoperative dysarthria was noted. Nine patients had follow-up examinations 2 months to 3 years following surgery. Some persistent improvement in the MD was noted in all. Of three patients whose dysarthria was worse at 3 to 4 months, subsequent improvement was noted at 9 to 12 months in two. Stereotaxic thalamotomy appears to be an effective form of treatment for persistent posttraumatic MD. The major limitation is increased postoperative dysarthria. Further studies to evaluate risk factors associated with dysarthria and further refinement to prevent its occurrence are needed.