Middle ear myoclonus

Abstract

Myoclonus is an involuntary, sudden jerking of a muscle or group of muscles. Middle ear myoclonus (MEM) is an idiopathic clinical entity attributed to causing abnormal repetitive contractions of the tensor tympani and/or stapedius muscles. MEM is an uncommon disorder produced by repetitive contractions of the middle ear muscles. In MEM, the objective tinnitus is produced by synchronous repetitive contraction of the tensor tympani and/or stapedius muscle. The exact etiology of MEM remains unclear. The diagnosis of MEM is often based on the history of rhythmic and involuntary clicking or buzzing tinnitus which is invariably unilateral. The important differential diagnosis of the MEM is palatal myoclonus while other local otological diseases must be excluded with careful clinical examination. Transcanal microscopic/endoscopic middle ear exploration with the injection of botulinum toxin into the tensor tympani and stapedius muscles is helpful to relieve the symptoms of MEM. This approach is both helpful as a diagnostic and therapeutic tool that allows temporary paralysis of the middle ear muscles before providing definitive surgical treatment. The surgical section of the middle ear muscles through tympanotomy is an excellent treatment option for MEM. There are not adequate research articles available concerning MEM and mainly case reports and few case series are available during the literature search. Proper methods for diagnosis and treatment of MEM are helpful to early resolution of the symptoms and enhance the quality of life. Here, this review article is attempting to discuss the etiopathology, clinical manifestations, diagnosis, and medical and surgical treatment of MEM. Literature search for MEM was done from the database of PubMed, MEDLINE, Scopus, and Google Scholar search with the use of the words MEM, middle ear muscles contractions, symptoms of MEM, diagnosis of MEM, and treatment of MEM.

Keywords

• middle ear myoclonus
• stapedius
• tensor tympani
• tinnitus