Eye Movement Abnormalities During Different Periods in Patients with Vestibular Migraine

PURPOSE: The aim of this study was to assess abnormal eye movement signs during different periods, namely, ictal periods and symptom-free intervals, in patients with vestibular migraine. PATIENTS AND METHODS: We assessed oculomotor signs using videonystagmography in 90 patients with VM (40 during ictal periods and 50 during symptom-free intervals) according to validated diagnostic criteria. RESULTS: Abnormal saccades, smooth pursuit and optokinetic test results; spontaneous nystagmus; and positional nystagmus were all observed in vestibular migraine patients, and there was no significant difference between different periods. Positional nystagmus was the most common in both the ictal and asymptomatic periods (60% and 36%, respectively). Positional nystagmus was induced in a variety of positions during both periods, and the slow-phase velocity ranged from <2 to 10°/s. The duration of positional nystagmus was over 60s in most cases. Overall, central oculomotor dysfunctions occurred in 27.5% of patients during VM attacks and 4% of patients during symptom-free intervals; this difference was statistically significant (p = 0.002). CONCLUSION: In patients with VM, abnormal oculomotor signs can be found during both vertigo attacks and asymptomatic intervals. Positional nystagmus is the most common of these abnormalities and can be induced in different positions. The amplitude of these patients’ positional nystagmus tends to be low, and the duration tends to be long. Observing changes in eye movements by videonystagmography may be helpful in the diagnosis of VM.