Epidemiology of vertigo, migraine and vestibular migraine.

Both migraine and vertigo are common in the general population with lifetime prevalences of about 16 % for migraine and 7 % for vertigo. Therefore, a concurrence of the two conditions can be expected in about 1.1 % of the general population by chance alone. However, recent epidemiological evidence suggests that the actual comorbidity is higher, namely 3.2 %. This can be explained by the fact that several dizziness and vertigo syndromes occur more frequently in migraineurs than in controls including benign paroxysmal positional vertigo, Meniere's disease, motion sickness, cerebellar disorders and anxiety syndromes which may present with dizziness. In addition, there is increasing recognition of a syndrome called vestibular migraine (VM), which is vertigo directly caused by migraine. VM affects more than 1 % of the general population, about 10 % of patients in dizziness clinics and at least 9 % of patients in migraine clinics.Clinically, VM presents with attacks of spontaneous or positional vertigo lasting seconds to days. Migrainous accompaniments such as headache, phonophobia, photophobia or auras are common but not mandatory. Cochlear symptoms may be associated but are mostly mild and non-progressive. During acute attacks one may find central spontaneous or positional nystagmus and, less commonly, unilateral vestibular hypofunction. In the symptom-free interval, vestibular testing adds little to the diagnosis as findings are mostly minor and non-specific. In the absence of controlled studies, treatment of VM is adopted from the migraine sphere comprising avoidance of triggers, stress management as well as pharmacotherapy for acute attacks and prophylaxis.