Acute Bilateral Superior Branch Vestibular Neuropathy

Abstract

The rapid onset of a bilateral vestibular hypofunction (BVH) is often attributed to vestibular ototoxicity. However, without any prior exposure to ototoxins, the idiopathic form of BVH is most common. Although sequential bilateral vestibular neuritis (VN) is described as a cause of BVH, clinical evidence for simultaneous and acute onset bilateral VN is unknown. We describe a patient with an acute onset of severe gait ataxia and oscillopsia with features compatible with acute BVH putatively due to a bilateral VN, which we serially evaluated with clinical and laboratory vestibular function testing over the course of 1 year. Initially, bilateral superior and horizontal semicircular canals and bilateral utricles were impaired, consistent with damage to both superior branches of each vestibular nerve. Hearing was spared. Only modest results were obtained following 6 months of vestibular rehabilitation. At a 1-year follow-up, only the utricular function of one side recovered. This case is the first evidence supporting an acute presentation of bilateral VN as a cause for BVH, which would not have been observed without critical assessment of each of the 10 vestibular end organs.

Functional Testing of Vestibulo-Spinal Contributions to Balance Control: Insights From Tracking Improvement Following Acute Bilateral Peripheral Vestibular Loss

“…In stark contrast, sacculus c-VEMP responses were normal, and utriculus o-VEMP responses were only weaker than normal on the right side. This report differs from a previous report of an acute BVL patient with only modest improvement in patient symptoms (22) in 3 aspects. Firstly, in our patient the loss involved all canal VOR responses and not just those served by the superior vestibular nerve (lateral and anterior canals).…”

Spontaneous Recovery of the Vestibulo-Ocular Reflex After Vestibular Neuritis; Long-Term Monitoring With the Video Head Impulse Test in a Single Patient

“…(3), if at the same time it is called acute bilateral superior branch vestibular neuropathy (13). If hearing is also involved then the inner ear is assumed to be the site of lesion and the diagnosis becomes labyrinthitis (14).…”

“…If the patient also develops Benign Positional Vertigo (BPV) the term neurolabyrinthis ( 12 ) is used. If the other side is involved later, then this is called bilateral sequential vestibular neuritis ( 3 ), if at the same time it is called acute bilateral superior branch vestibular neuropathy ( 13 ). If hearing is also involved then the inner ear is assumed to be the site of lesion and the diagnosis becomes labyrinthitis ( 14 ).…”

Role of video head impulse test to indentify the site of lesion in patients with vestibular neuronitis

“…There was a reduction of VOR gain in bilateral lateral and anterior canals with posterior canal VOR gain being normal. 13 Isolated involvement of inferior vestibular nerve in vestibular neuronits is very rare. In a retrospective review by Kim et al, only 9 cases of 703 patients with vestibular neuronitis were found to have affected inferior vestibular nerve.…”