Images in Clinical Medicine
Essential Palatal Myoclonus
N Engl J Med 2010; 362:e64May 27, 2010
- Article
Video
Involuntary Movement of the Uvula and Soft Palate.
A healthy 18-year-old woman presented with a 3-year history of progressively worsening involuntary movement of the uvula and soft palate. The movement was repetitive and rhythmic (see video) and had an associated auditory click. Initially, the movement was voluntarily suppressible, did not occur during sleep, and was not distressing to the patient. Subsequently, the movement increased in intensity and became more difficult to suppress. It affected the patient's swallowing and speech and often kept her awake at night. Magnetic resonance imaging of the brain was normal, with no evidence of a causative structural lesion. Results of an autoimmune workup and analysis of the cerebrospinal fluid were unremarkable. A diagnosis of essential palatal myoclonus was made. Essential palatal myoclonus is a rare movement disorder that is caused by rhythmic contractions of the tensor veli palatini muscle. Although it resembles a tremor, the movement is repetitive rather than oscillatory and involves contraction of agonist muscles only. The cause of the auditory ear click is unknown, but it occurs more commonly in essential palatal myoclonus, which is idiopathic, than in symptomatic palatal myoclonus that is secondary to a structural lesion in the brain stem. In this patient, trials of clonazepam, valproic acid, and carbamazepine were ineffective. An injection of botulinum toxin into the tensor veli palatini muscle resulted in notable improvement in symptoms. Several months after the injection, the patient continued to have mild symptoms that she did not find disruptive.
James Scozzafava, M.D.
Jerome Yager, M.D.
University of Alberta, Edmonton, AB, Canada
jjs9@ualberta.ca
