The minimal caloric test asymmetric response in vertigo-free migraine patients

Abstract

In 1860, Brown Séquard 1 described vertigo and disequilibrium after cold water injection into the ear. One year later Prosper Ménière 2 localized the vertigo sensation in the inner ear. In 1906, Robert Bárány 3 popularized the procedure of irrigating the ears with 10 to 20 cc of cold water to produce a marked nystagmus. Kobrak, in 1920 and 1923 4 attempted to use less amount of water to minimize the associated discomfort and side effects of the caloric testing. In 1942, Fitzgerald and Hallpike 5 described their caloric method in which the ears were irrigated for forty seconds with water 7°C above and below body temperature. In 1968, Linthicum 6 described The Minimal Caloric Test (MCT) consisting of only 0.2 cc ice water instillation in the external ear canal. With the purpose to confirm Linthicum results, Nelson 7 reviewed the MCT and proved its efficacy. Along the same minimalist line, Weinberg J. et al.8 suggested that the MCT can be done with an eardrum stimulus by a simple wet cotton wood. In the last decades, few vestibular studies have used the MCT 9 .Migraine is one of the most common primary headaches 10,11 . Vertigo symptoms are well known in migraine 12,13 and vestibular dysfunctions have been found in migraineurs 14. To further investigate vestibular dysfunction in migraine, in this study -a byproduct of a larger bedside tests study 15 -30 vertigo-free migraine patients and 30 paired controls were evaluated to test the hypothesis that vertigo-free migraine patients present vestibular dysfunctions as detected by the MCT. MeThod AbsTrAcTVertigo symptoms and subclinical vestibular dysfunctions may occur in migraine. The Minimal Caloric Test (MCT), an easy-to-perform, convenient and yet informative procedure was used to test the vestibular function in 30 vertigo-free migraine patients outside attacks and 30 paired controls. Although not statistically significant, a right-to-left nystagmus duration asymmetry greater than 25% was present in both groups. This difference was greater in the patients group, suggesting the presence of subclinical vestibular imbalance in migraine.Keywords: migraine, vestibular system, minimal caloric test.resuMo Vertigem e alterações vestibulares subclínicas têm sido identificadas na enxaqueca. O teste calórico mínimo é simples de realizar, informativo e conveniente. Ele foi realizado em 30 pacientes com enxaqueca sem queixa de vertigem e 30 controles pareados. Embora não estatisticamente significativo, ocorreu assimetria direita-esquerda superior a 25% na duração do nistagmo em ambos os grupos, maior nos pacientes, o que sugere a presença de desequilíbrio vestibular subclínico na enxaqueca.Palavras-chave: enxaqueca, sistema vestibular, teste calórico mínimo. 146Arq Neuropsiquiatr 2016;74(2):145-148September 2013. Subjects were first examined to rule out the presence of spontaneous nystagmus and the external ear canal (EEC) were inspected to both dispel any earwax obstruction and to evince the canal shape trough the tympanic membrane. Other excluding criteria included spontane...