Micropressure therapy is a minimally invasive therapy for Ménière’s disease that uses a soft probe inserted into the external ear canal. This delivers pressure pulses to the inner ear from a portable pressure generator. Its use is based on the observation that pressure changes applied to the inner ear result in improved vertigo control in patients with Ménière’s disease. A standard ventilation tube (or pre-existing perforation of the ear drum) is required for a micropressure device to be used. A treatment cycle takes a few minutes and is repeated three times a day. Several studies have suggested beneficial vertigo control with minimal risk of complications.
For patients in whom disabling vertigo continues to be the dominant symptom despite reasonable trials of medical management, chemical labyrinthectomy should be considered. Gentamicin is the most commonly used ototoxic agent. The aim of treatment is to gradually reduce hair cell function in the vestibular system of the affected ear. Gentamicin is relatively vestibulotoxic but leaves the cochlear hair cells intact, making it suitable for treatment of intractable vertigo in ears with functional hearing. Gentamicin can be administered under local anaesthesia by a transtympanic injection or via a grommet to the affected ear, thereby sparing toxicity to the unaffected ear in unilateral disease or the inactive ear in bilateral disease.
A commonly used fixed-dose transtympanic protocol involves a single injection of gentamicin (40 mg in a 2 mL solution, off-label use) to the middle ear, with a second injection four weeks later if the vertiginous episodes continue. Most outcome studies of gentamicin report greatly improved vertigo control. The effect on the vestibular hair cells is permanent and irreversible, with a small risk of associated hearing loss.
Endolymphatic sac surgery, labyrinthectomy and vestibular nerve section
Surgery on the endolymphatic sac has been a major treatment for intractable vertigo. However, more recent analysis of the outcomes of sac surgery have shown it to be no better than placebo treatments (simple mastoidectomy), leading to a decline in its popularity as a treatment of Ménière’s disease.
Complete unilateral surgical deafferentation of the vestibular system in the affected ears via labyrinthectomy or vestibular nerve section have also lost popularity. Although highly effective in controlling vertigo, these procedures carry the risk of total hearing loss, facial nerve palsy and neurosurgical complications related to entering the posterior fossa. Surgical treatment of Ménière’s disease has been largely replaced by transtympanic application of gentamicin, because of the latter’s ease of administration and relative safety.
Management of active Ménière’s disease focuses on reducing the frequency and severity of vertiginous attacks. This can be satisfactorily achieved in most patients with a combination of the interventions described above. However, in some patients with severe disease and particularly those with bilateral Ménière’s disease, disabling disequilibrium (poor balance) persists between each cluster of vertiginous attacks. This is usually because of insufficient residual vestibular function in longstanding end-stage disease.
A current experimental intervention is the vestibular electronic implant. This comprises an implanted device with three electrodes, one placed in each of the end organs of the affected semicircular canals, attached to a microprocessor (analogous to a cochlear implant), which can sense changes in head posture and position. The aim of the device is to simulate vestibular function during head movement with the hope of improving balance control and quality of life in patients with end-stage vestibular disease.