Isolated myoclonus of the vocal folds

Abstract

Objective: Laryngeal manifestations of stroke play a significant role in the morbidity and mortality among affected patients. The objective of this article was to describe unique myoclonic vocal fold movement disorder, which is an unusual post-stroke manifestation.

Study design: A retrospective case study.

Setting: The study group included post-stroke patients with dysphagia who were referred to the Swallowing Clinic at Edith Wolfson Medical Center.

Subjects and methods: All patients underwent flexible laryngoscopy and flexible endoscopic evaluation of swallowing with sensory testing. The vocal fold movement was analyzed with the Sisson-Ammons video analysis system.

Results: Three post-pontine stroke patients presented with vocal fold myoclonus (VFM). The myoclonus was spontaneous, unintentional, and irregular (19-420 jerks per minute). Two patients presented with unilateral myoclonus, ipsilateral to the brainstem stroke. One patient, who experienced subsequent pontine strokes, presented with bilateral VFM. When patients were asked to swallow or phonate, the myoclonus disappeared.

Conclusion: Isolated VFM is an unusual manifestation of pontine injury, resulting in a sudden, involuntary, and non-rhythmic vocal fold movement. This laryngeal pathology is not associated with either dyspnea or dysphonia and most likely not with inefficient swallowing.