Investigation of the Coherence of Definite and Probable Vestibular Migraine as Distinct Clinical Entities

Objectives: To investigate the following: 1) associations between vestibular symptoms and migraine in a well-characterized cohort of tertiary neurotology patients, 2) effects of comorbidity on clinical presentations, and 3) validity of proposed definitions of definite (dVM) and probable vestibular migraine (pVM). Study Design: Retrospective chart review. Setting: Tertiary neurotology center. Patients: All 228 subjects with headache were selected from a larger investigation of 410 patients with vestibular symptoms who underwent comprehensive medical, surgical, and behavioral neurotologic consultations. Subjects had at least one of 4 diagnoses: dVM/pVM, Meniere's disease, benign paroxysmal positional vertigo, or chronic subjective dizziness. Interventions: Subjects were divided into migraine (n = 164) and nonmigraine headache (n = 64) groups by International Headache Society criteria, then subdivided by those with vestibular symptoms related or unrelated to headache. Subjects meeting proposed criteria for dVM (n = 46) and pVM (n = 42) were identified. Statistical analyses investigated discriminating features and cohesiveness in each group, with or without comorbidity. Main Outcome Measures: Characteristics of dVM and pVM. Results: Migraine, particularly migraine with aura, was more often related to vestibular symptoms than nonmigrainous headache. dVM and pVM groups did not differ in demographics, clinical histories, examinations, or vestibular testing. Numerous differences existed between dVM/pVM subjects with and without comorbid Meniere's disease, benign paroxysmal positional vertigo, or chronic subjective dizziness. The pVM group contained 4 subtypes. Conclusion: These results support an association between vestibular symptoms and migraine but not proposed distinctions between dVM and pVM. pVM does not appear to be a coherent diagnostic entity. Comorbid conditions are important causes of vestibular symptoms in patients with migraine.