Comparative Analysis of Vestibular Dysfunction and Compensation in Ramsay-Hunt Syndrome and Vestibular Neuritis.

Objective: To investigate vestibular loss and compensation in Ramsay-Hunt syndrome with dizziness (RHS-D) and vestibular neuritis (VN).

Study design: Retrospective cohort study from 2019 to 2023.

Setting: Tertiary care neurotology practice.

Methods: Patients with RHS-D or VN who underwent videonystagmography, including cervical vestibular evoked myogenic potential (cVEMP), caloric stimulation, rotary chair, and oculomotor testing, were reviewed and stratified by vertigo etiology. The main outcome measures were rates and severity of vestibular loss, as measured by cVEMP and caloric stimulation, and of vestibular compensation, as measured by rotary chair and oculomotor testing.

Results: Ten patients were found to have RHS-D and 22 with VN. Caloric and cVEMP abnormalities were noted in 100 and 70% of RHS-D patients compared to 60 and 20% with VN (P = .029 and P = .034, respectively). RHS-D patients were significantly more likely to present with concurrent caloric and cVEMP abnormalities compared to VN (70 and 13%, respectively; P = .009). Vestibular loss appeared more severe in RHS-D compared to VN suggested by significantly lower mean bithermal slow phase velocity sum (3.8 and 21 degrees per second, respectively), greater canal paresis (78.7 and 40.2%, respectively), and greater cVEMP amplitude asymmetry (64 and 31%, respectively) (P = .014, P < .001, and P = .053, respectively). Regarding vestibular compensation, abnormal gain asymmetry was present in 88% of RHS-D patients with a mean asymmetry of 31.2 compared to 11% in VN with a mean of 14.0 (P = .019 and P = .003, respectively).

Conclusion: Compared to VN, RHS-D patients appear to suffer from a more profound vestibular loss and a worsened ability to compensate for such deficits.