Bilateral vestibular failure is a rare, often unrecognised, clinical entity (0.6%–2% of all routinely performed electronystagmography), characterised by unsteadiness of gait and oscillopsia during head movements.1 The unsteadiness is due to loss of the vestibulospinal reflexes. It increases in darkness or when walking on uneven or soft ground—that is, when visual and somatosensory inputs, necessary for vestibular substitution, get compromised. Oscillopsia is an illusory movement of a stationary surrounding which occurs typically during locomotion as a result of a retinal slip due to an insufficient vestibulo-ocular reflex. The diagnosis of bilateral vestibular failure can be supported clinically by the finding of an abnormal visuo-ocular reflex (doll's eyes), and an abnormal gaze fixation with compensatory saccades during rapid head turns (the head thrust test). A bithermal caloric test or a rotational chair test confirms the diagnosis by demonstrating the absence of vestibular responses.1

Ototoxic drugs (for example, aminoglycosides) are the most common cause of bilateral vestibular failure, followed by sporadic multisystem degeneration, infectious meningitis, bilateral cerebellopontine angle tumours, and autoimmune disorders. Neuropathies (such as vitamin B12 deficiency, hereditary polyneuropathies, and sarcoidosis), sequential vestibular neuronitis, and bilateral Menière's disease also often lead to bilateral vestibular failure.1-3 Bilateral vestibular failure due to leptomeningeal metastasis has been reported to occur as a part of the clinical picture of carcinomatous meningitis, including symptoms of increased intracranial pressure, multiple cranial and spinal nerve involvement, and changes in mental state.1 3 4 We report on a patient with carcinoma of the breast where rapidly progressive bilateral vestibular failure was the main and outstanding presenting symptom of leptomeningeal spread.

A 73 year old woman was admitted because of progressive gait unsteadiness, bilateral tinnitus, …