Recovery of vestibular function after vestibular neuritis
Reviewed by Victor Osei-Lah

It is well known that recovery from vestibular neuritis (VN) is not solely mediated through central vestibular compensation, but also at the peripheral level. The authors conducted a prospective study to track the dynamic changes in recovery from vestibular neuritis using objective measures (VFTs) – caloric test, vHIT, rotatory chair testing, VEMPs – and functional scales (Dizziness Handicap Inventory DHI and dynamic dizziness scale VAS-DD). Sixteen patients with acute vestibular neuritis were tested within seven days of onset and after 6–12 months. Twenty healthy adults served as controls. Of interest, all patients were given corticosteroids (prednisone) tapering over 10 days, oral valaciclovir 300mg twice daily for seven days, and commenced on vestibular rehabilitation within one week. At onset, VFTs confirmed that the superior vestibular nerve was affected in 100% of patients and, in 31% of patients, both superior and inferior vestibular nerves were affected. In 93%, 43% and 25% of patients, the horizontal, posterior and anterior canal function, respectively, were abnormal at onset. At 6–12 months, posterior canal function had returned to normal. Rotatory chair testing asymmetry was abnormal in all patients at onset but returned to normal in all but one patient at 6–12 months. Several parameters were analysed, making the results difficult to follow. For some reason, even though all peripheral receptors were tested, their main conclusion was based on the function of the horizontal canal, i.e. at 6–12 month follow-up, 44% of the ultralow frequency, 94% of the low-to-mid frequency, and 44% of the high-frequency function of the horizontal semicircular canal returned to normal. One other conclusion was that rotatory chair testing could be used to assess the overall improvement after VN. Many centres do not have the rotatory chair. The authors reported no significant correlation between the change in DHI score or change in VAS-DD and the degree of vestibular function recovery. The poor correlation between vestibular symptoms and vestibular function abnormalities is well documented.

Dynamic change of vestibular function and the long-term prognosis of vestibular neuritis.
Guo P, Zhao J, Jia G, et al.
J VESTIB RES
2023;33(6):411–22.