Comparison of electromechanical measures and observer ratings of tardive dyskinesia.

Thirty-three patients with tardive dyskinesia (TD) were studied with multiple-observer consensus ratings of videotaped examinations, ultrasound counts of movement, and electromechanical frequency measures of the movements. There were statistically significant correlations between orofacial ultrasound measures and TD severity determinations made by observers. Clinical ratings did not correlate with frequency measures. Ultrasound measures substantiate observer rating scales, whereas frequency measures appear to provide information not available from clinical rating scale scores.