Twitching sensation in the eardrum due to bilateral myoclonus of the tensor tympani

Abstract

Middle ear myoclonus is a pathological involuntary movement of the ossicular muscles and is one of the causes of objective tinnitus. Symptoms include twitching of the eardrums and hyperacusis, which may make diagnosis difficult. We diagnosed the patient in this case with stapes muscle tinnitus based on symptoms that included twitching of the eardrums during loud noises and stapedius reflex responses. In the first operation, surgical tenotomy of the stapedius tendon was performed under general anesthesia, but the symptoms recurred although a temporary course was observed. After that, involuntary movements of the eardrum and unstimulated stapedius reflex, which could not be confirmed by the first operation, showed swaying of the baseline, and we reached a diagnosis of tensor tympani myoclonus. In this case, surgical tenotomy of the tensor tympani tendon under local anesthesia improved symptoms.

There have been many reports showing that surgical treatment is highly effective, but preoperative planning is important to avoid inner ear damage; it is necessary to confirm involuntary movements of the tympanic membrane and contractions of causatives ossicular muscles under local anesthesia.