Dystonia secondary to electrical injury: surface electromyographic evaluation and implications for the organicity of the condition

We describe a patient who developed right arm dystonia following an electrical injury. The patient's arm remained adducted, and flexed at the elbow and wrist, with all movement resulting in pain and tremor. Surface electromyographic evaluation revealed constant tonic activity of multiple upper and lower arm muscles at rest, that was not distractible. Voluntary and passive movement of the elbow or wrist resulted in high amplitude EMG activity, with motor grouping at 11 Hz at the elbow and 8 Hz at the wrist. Although a diagnosis of psychogenic dystonia was entertained, the stereotyped nature of the movement disorder and lack of variability on clinical and surface EMG evaluation support an organic disorder that was temporally-related to an electrical injury.