12Middle-Ear and Palatal Myoclonus — Surgery and Botulinum Toxin

FObjective tinnitus from a moving structure

Most tinnitus is subjective — a phantom sound only the patient hears. Myoclonic tinnitus is different: it arises from the rhythmic contraction of a real muscle, and the sound it makes can sometimes be detected by an examiner, making it one of the few truly objective tinnitus syndromes [2013]. Two muscle groups are responsible.

In middle-ear myoclonus (MEM), repetitive contraction of the tensor tympani or stapedius tendon jerks the ossicular chain, producing a clicking, fluttering or thumping that is often irregular and can be triggered by sound or by eyelid closure [2025]. In palatal myoclonus (palatal tremor), rhythmic contraction of the soft-palate muscles — chiefly the tensor veli palatini or levator veli palatini — opens and closes the Eustachian tube, generating a regular clicking heard in the ear [2023].

TRecognising and localising the click

The history is distinctive: a clicking or fluttering rather than a tone, often rhythmic, sometimes stoppable by jaw movement or audible to a bystander. The key clinical task is to localise the moving structure, because that determines treatment. Otoscopy during an attack may show rhythmic tympanic-membrane movement in MEM. Examining the soft palate — ideally with flexible nasendoscopy — reveals synchronous palatal contractions in palatal myoclonus.

Tympanometry or wide-band acoustic-reflex recording can capture the rhythmic impedance changes of MEM objectively. An important distinction is between essential palatal tremor, which typically involves the tensor veli palatini, produces the ear click and often vanishes in sleep, and symptomatic palatal tremor from a brainstem lesion of the Guillain–Mollaret triangle, which involves the levator, persists in sleep, and mandates MRI to exclude stroke, demyelination or tumour [2023].

CConservative measures come first

Treatment is staged, and the first stage is non-surgical because many cases are self-limiting or stress-related. Reassurance and explanation alone help when the symptom is mild. Muscle-relaxant and anticonvulsant trials — for example carbamazepine, clonazepam or baclofen — are reasonable, working on the principle of dampening the abnormal rhythmic discharge, though evidence is limited and benefit inconsistent [2025].

For palatal tremor, identifying and treating an underlying brainstem cause takes priority. Only when symptoms are genuinely disabling and conservative and pharmacological measures have failed should an interventional step — tendon section for MEM, botulinum toxin for palatal myoclonus — be offered. This staged caution mirrors the wider principle that procedures for tinnitus demand careful selection.

CTendon section for middle-ear myoclonus

When refractory MEM is convincingly localised to the middle ear, surgical section of the stapedius and/or tensor tympani tendons removes the offending muscle pull on the ossicular chain. Historically done through a tympanomeatal flap, it is now frequently performed with a transcanal endoscopic technique: the tendons are identified and divided, silencing the click while preserving hearing [2023].

Outcomes are generally good in well-selected, correctly localised patients, with most reporting resolution or marked reduction of the click and a low complication rate. Because the procedure is irreversible, the diagnosis must be secure — rhythmic tympanic-membrane movement or objective impedance changes — before committing, since cutting tendons in a patient whose click is actually palatal will fail.

CBotulinum toxin for palatal myoclonus

For palatal myoclonus, the targeted treatment is botulinum toxin injection into the culprit palatal muscle — typically the tensor veli palatini for essential palatal tremor causing the ear click, or the levator veli palatini in symptomatic forms. The toxin chemically weakens the muscle, abolishing the rhythmic Eustachian-tube movement and with it the click [2013].

An algorithmic approach, guided by which muscle is clicking and by nasendoscopic localisation, improves results and reduces side-effects [2014]. The main trade-offs are temporary: targeting the tensor veli palatini risks Eustachian-tube dysfunction and a sense of ear fullness, while levator injection can cause transient velopharyngeal insufficiency with nasal regurgitation or hypernasal speech. Because the effect wanes over months, injections must be repeated — making patient counselling about the ongoing nature of therapy essential.