Migrainous vertigo: results of caloric testing and stabilometric findings.

Background: Association between migraine and vertigo has been widely studied during the last years. A central or peripheral vestibular damage may occur in patients with migrainous vertigo. Despite much evidence, at present the International Headache Society classification does not include a specific category for migrainous vertigo.

Objectives: To assess the prevalence of central and peripheral vestibular disorders and postural abnormalities in patients diagnosed as affected by definite migrainous vertigo according to Neuhauser.

Methods: Thirty patients with migraine and acute vertigo lasting from minutes to hours underwent a full otoneurological screening for spontaneous, positional, and positioning nystagmus with head-shaking and head-thrust (Halmagyi) tests, an audiometric examination, and videonystagmography with bithermal stimulation according to Freyss. Videonystagmographic findings were compared with those of 15 migraineurs without lifetime vertigo (group M). Next day, a static posturography was performed; posturographic results have been compared with those of a second control group of 30 healthy patients matched for age and sex (group C).

Results: In total, 14 subjects with migrainous vertigo showed otovestibular disorders; 6 subjects showed impaired vestibulo-oculomotor reflexes (20%). Five more patients had bilateral increased responses (16.6%). Five patients showed signs of central brainstem or cerebellar disorders for altered pursuit or saccades or positional direction changing nystagmus. Stabilometric results returned higher values of Length and Surface above all when testing was performed in eyes closed conditions compared with the normal control group. The subgroup of 14 subjects with migrainous vertigo and vestibular abnormalities performed poorly in stabilometric exams and seemed to rely more on visual cues in balance control than the subgroup of 16 subjects with migrainous vertigo but without abnormalities.

Discussion: Our results indicate that vestibular functional damage may occur in all vestibular pathways; central and peripheral signs are equally represented. Our data are not inconsistent with the hypothesis that a vestibulo-spinal dysfunction is the causal factor for the posturographic results. Moreover, the Visual Romberg Index is significant for increased visual cue dependence in migraineurs.