’Speaker’s cramp’, a new type of involuntary mouth-, lip-muscle movement

A task-related spasmodic contraction of the muscles of the mouth and jaw, causing involuntary movements of the mouth and lips (oromandibular dystonia), manifesting only during speech as grimacing and sound distortion, has been diagnosed by a research team in Copenhagen, Denmark, and termed “Speaker’s Cramp”.

Symptoms were reduced when the affected muscles were treated with Botox® injections.

Patients rated their speech difficulties on visual analogue scales, and video recordings for dystonia scores and neurological and odontological examinations were used for evaluation. Surface and needle electromyography (EMG) was applied to locate dystonic activity and guide injections of Botox® into the affected muscles. After baseline recordings, the patients were followed for two to three years, with Botox® injections every 3-4 months and evaluation once or twice between treatments.

In response to treatment, patients reported marked improvement in and relief from the grimacing and speech difficulty associated with Speaker’s Cramp. The level of digastric muscle activity was important and reflected the severity of the condition.