Neck Vibration-Evoked Nystagmus in Vestibular Migraine: Mechanistic Insights into Role of Proprioception

Abstract Introduction Vestibular migraine is a major cause of recurrent vertigo, yet its mechanisms and diagnostic markers remain limited. Abnormal vestibular–cervical integration and convergence insufficiency, reflected by impaired near point convergence (NPC),suggest multisensory dysfunction. This study tested whether cervical proprioceptive perturbation provokes vertigo and nystagmus in vestibular migraine and evaluated NPC as a predictor of these responses. Methods Fifty-one vestibular migraine patients and 12 controls underwent interictal vestibular testing. Peripheral function was assessed with vHIT. Participants received randomized 100-Hz cervical (proprioceptive) and mastoid (vestibular) vibration without visual fixation, with eye movements recorded via video Frenzel goggles and NPC measured using standard methods. Analyses included McNemar’s, Wilcoxon signed-rank, Mann–Whitney U, correlations, and multivariable logistic regression. Results Neck vibration provoked vertigo in all vestibular migraine patients and none of the controls, producing nystagmus in 76.5%. Horizontal, ipsiversive nystagmus predominated, while less frequent vertical responses showed higher velocities. Mastoid vibration elicited no nystagmus. NPC was the only independent predictor of nystagmus and correlated with slow-phase velocity and bilateral responses. Age correlated with drift velocity, whereas vestibulo-ocular reflex gain showed no association. Discussion Neck vibration elicits vertigo and nystagmus in vestibular migraine, providing the first objective physiological marker. NPC predicts and correlates with nystagmus severity, highlighting its value as a surrogate of multisensory dysfunction. Together, these findings implicate abnormal cervical–vestibular integration and position NPC and neck-vibration testing as practical tools for diagnosis and phenotyping. Key points Vestibular migraine affects ∼3% of population yet remains highly controversial. Objective measures reveal reproducible vertigo and nystagmus in vestibular migraine. Impaired convergence strongly predicts vibration-induced nystagmus in VM patients. Findings support sensory mismatch model linking cervical proprioception to vertigo.