Abstract
Introduction
Middle Ear Myoclonus (MEM) is a rare type of rhythmic tinnitus caused by repetitive contraction of the middle ear muscles. Patients present with symptoms of ear ringing, hissing and bubbling which may be persistent or intermittent [1]. Correct identification and differentiation will improve the patient's management. We discuss the heterogeneity of the diagnosis along with the acoustogenic mechanism and pathophysiological process involved.
Case Presentation
A 81 year-old, male with a history of mild anxiety and insomnia, complained of one year history of clicking sensation in both ears heard mostly in the daytime and absent during sleep, it occasionally induced a headache. The symptom started in the right ear, and occasionally also involved the left ear. It had an on and off characteristic, mostly unilateral and sometimes bilateral. The presentation was not accompanied by ear pain or ear discharge. He had no change in his vision, voice quality, or speech production. The patient denied a history of involuntary movements, bruxism, vertigo, abnormal facial expressions, as well as a family history of movement or other neurological disorders. At physical examination, clicking was perceived by the patient and heard by the examiner near the patient’s right ear, oral examination showed no evidence of abnormal movements of the palate and pharynx. Otomicroscopy, demonstrated inward and outward movements of the tympanic membrane but difficult to elicit synchronous movement due to low noise environment. Audiometry revealed mild sensorineural deafness in the right ear. Tympanometry revealed type A curve with ear canal volume ranging between 1.11 cc and 1.26 cc in both ears. Doppler study of Bilateral carotid and vertebral arteries as well as High resonance computed tomography of temporal bones demonstrated no abnormality.
Discussion
The diagnosis of MEM is based on a history of pulsatile tinnitus [3]. Definitive diagnosis should be done with observation of rhythmic movements of the Tympanic membrane synchronous with the tinnitus, and impedance changes on tympanometry as well as long-time-based tympanometry [3]. The patient received education about surgical interventions available however the patient refused surgery or any further investigations, the tinnitus was managed with masking devices (hearing aids). As we couldn’t correlate the symptoms with other diagnoses, it is presently considered as a case of MEM. In this case, the presenting symptom (tinnitus) is persistent in the patient and has not responded to any treatment measures.
The differential diagnosis considered were Palatal Myoclonus (Normal physical examination findings), Patulous Eustachian tube (Tympanometry findings were normal), Age-related sensorineural deafness (May not produce persistent rhythmic tinnitus), Vascular bruits (Normal Doppler study), Cerebellopontine angle tumor (No abnormality found in HRCT).
The follow-up investigations needed to be done are Long time based Tympanometry, Acoustic Reflex Decay test and Impedance tympanogram-static compliance.
Conclusion
Middle Ear myoclonus is a heterogeneous syndrome and a misnomer as the underlying etiology may not necessarily be myoclonus [1]. Management of patients should be done stepwise starting from medical to surgical interventions. We insist on continuous research on management of Bilateral middle ear myoclonus due to the limited availability of literature resources.
