The effect of migraine and motion sickness on symptoms evoked by the caloric vestibular test.

Background: The caloric vestibular test (CVT) may evoke headache and vestibular symptoms in susceptible people. Patients with migraines have higher susceptibility to motion sickness. In migraines, impaired habituation to repetitive stimuli is a well-known interictal abnormality.

Objective: This study is aimed at evaluating CVT-evoked headache, nausea, vomiting, and imbalance in patients with and without migraine and/or motion sickness.

Methods: A retrospective data analysis was performed on 554 patients with a complaint of dizziness who underwent bithermal CVT at a tertiary referral center. The occurrences of CVT-evoked headache, nausea, vomiting, and imbalance were observed in four groups: patients with only migraine (MG; n = 94), those with only motion sickness (MSG; n = 89), those with migraine and motion sickness (MMSG; n = 122), and those without migraine and motion sickness (non-MMSG; n = 146). The differences between the groups were assessed.

Results: The mean ages of groups were similar (p = 0.534). The proportions of females were higher in the MG, MSG, and MMSG (p = 0.001). The severity of nausea and headache for each gender was higher in the MG, MSG, and MMSG (p < 0.001). Vomiting was more common in MMSG among males (p = 0.003), while there was no difference between groups among females (p = 0.099). Imbalance was more common in MMSG among females (p < 0.001). A relationship was detected between age and imbalance (p < 0.001), where an increased risk for imbalance was evident with greater age. Three patients in the MMSG needed hospitalization after CVT.

Conclusions: Special caution is needed when performing caloric testing for patients with migraines or MS since CVT-evoked symptoms may occur with higher incidence and intensity, which might be related to a lack of habituation in neuronal information processing after robust sensory stimuli like CVT.