Palatal myoclonus: Algorithm for management with botulinum toxin based on clinical disease characteristics

Abstract

To review the clinical characteristics and management of patients with palatal myoclonus and devise an algorithm for treatment with botulinum toxin based on presenting symptoms, clinical examination findings, and involved muscle groups. Retrospective chart review at two clinical research centers. Between 1985 and 2011, 15 patients with a diagnosis of essential palatal myoclonus were assessed. Data were collected on patient demographics, disease characteristics, and treatment outcomes. Patients were more commonly female (60.0% vs. 40.0%) with average age at onset of 35.6 years. In 40.0% of patients, the myoclonus began after a viral upper respiratory tract infection. Two-thirds of patients had been previously treated unsuccessfully with oral medications. Predominant presenting symptoms included clicking tinnitus (46.7%), nonaudible awareness of palatal movements ± rhinolalia (20.0%), or both (33.3%). Clinical examination revealed co-incident involvement of pharyngeal musculature in 53.3%. Palatal site for initial botulinum toxin injection depended on the predominant presenting symptom: for tinnitus, 2.5 U were injected transorally into the tensor veli palatini muscle at the level of the pterygoid hamulus/lateral soft palate; for palatal movements, the injection was placed medially on either side of the uvula. Dose and location of subsequent injections were tailored depending on response to the toxin and location of subsequent observed maximal muscular contractions. Palatal myoclonus can present with tinnitus or patient-perceived palatal movements. Management with botulinum toxin can be tailored to address the muscles contributing to the predominant presenting symptoms.