Nystagmus and Vertigo in Acute Vestibular Migraine Attacks: Response to Non-Invasive Vagus Nerve Stimulation

Objective: Vestibular migraine (VM) is the most common neurologic cause of vertigo in adults, but there are no currently-approved rescue therapies. This study describes the benefits of non-invasive vagus nerve stimulation (nVNS) on vertigo, headache, and nystagmus during VM attacks. Methods: Case series of four VM patients who were evaluated during acute VM episodes in a tertiary referral neurology clinic between February 2019 and January 2020. They underwent bedside neuro-otologic examination, and graded the severity of vertigo and headache using a 10-point visual-analog scale (VAS; 0 - no symptoms, 10 - worst ever symptoms), before and 15 minutes after nVNS. Results: Average vertigo severity was 5 (median 4.5) before, and 1.5 (median 0.5) after nVNS. Mean headache severity (three patients) before treatment was 4 (median 4), and 0.7 (median 0) after. Spontaneous right-beating nystagmus (Patient 1) nystagmus, upbeat nystagmus (Patient 2), and positional nystagmus (Patient 3) resolved with nVNS. Baseline left-beating nystagmus in Patient 4 from previous vestibular neuritis damped during acute VM but returned to baseline following nVNS. In all four patients, ictal nystagmus resolved, and examination findings returned to baseline. Conclusions: This study suggests nVNS may ameliorate vertigo and headache, as well as nystagmus associated with VM attacks. Larger, sham device-controlled studies are needed to elucidate the benefits of nVNS in VM.