Computer graphics in the assessment of severity of spasmodic torticollis: potential role in the evaluation of surgical treatment.

There is a need for objective evaluation of the effectiveness of treatment of spasmodic torticollis so that comparisons can be made between different therapies. Video tape recordings of patients undergoing surgery for spasmodic torticollis were digitized and the movement of a reference marker was tracked by computer. A graphic presentation of oscillation of the marker around a mean position was obtained. Comparison of preoperative and postoperative recordings enabled assessment of the effectiveness of surgery. The results can be tabulated, facilitating accurate documentation of large series of results in publication. This should enable easier comparison of the effectiveness of different therapies.