We read with much interest the report by Kleopa and Kyriakides 1 on a dystonic disorder of the lower lip. This disorder bears similarity to two of our own patients.
Case Reports Patient 1
Four years ago, at age 27 years, having experienced a severe headache during the night, on awakening this woman noticed slight dysfunction of the right oral musculature combined with a degree of numbness in the right cheek and right half of the tongue, whereas taste remained normal. Examination performed on the same day revealed no objective abnormalities besides some diminished function of the right corner of the mouth. We suspected the onset of Bell's palsy. Within a few weeks, a continuous lateral and outward protrusion of the right lower lip appeared, followed soon afterward by deviation of the jaw to the same side. The full picture consisted of lateral and outward protrusion of the right lower lip and deviation of the jaw to the right (see Video, Segment 1). While talking and making voluntary movements of the mouth and jaw, the abnormal postures might diminish momentarily. According to the patient's mother, the abnormal jaw and lip position did not disappear during sleep. On request, the patient could voluntarily keep the jaw and lip in a normal position for several seconds. If the jaw was pushed into its normal position and held there by the examiner, the lower lip automatically adopted its normal shape as long as the jaw was kept in this normal position. However, a geste antagonistique by the patient herself was not helpful. No abnormalities of the eyelid were found. There was slight hypoesthesia in the areas of nerve V II and V III . Two months after the first symptom, electromyography (EMG) showed normal blink and masseter reflexes. However, the right masseter and zygomaticus muscles showed reduced interference patterns and prolonged duration of motor unit potentials. The left internal pterygoid muscle showed spontaneous continuous motor activity, which diminished when the patient tried to move the jaw to the left by voluntary effort. The patient was treated with botuline toxin injections in the right lower lip and in the left internal pterygoid muscle. The effect on deviation of the jaw was minimal but the lower lip clearly improved with botuline toxin.