Acute migrainous vertigo: clinical and oculographic findings.

Migrainous vertigo (MV) is an increasingly recognized cause of episodic vertigo. However, the pathophysiology of MV is still a matter of speculation and it is not known to what extent the dysfunction is located in the central or peripheral vestibular system. The aim of this prospective study was to describe the clinical spectrum of acute MV and to clarify which structures of the vestibular system are involved. Testing of 20 patients with acute MV included neuro-otological examination, recording of spontaneous and positional nystagmus with 3D video-oculography, and audiometry. Pathological nystagmus was observed in 70% of patients during acute MV: six had isolated spontaneous nystagmus, five had isolated positional nystagmus and three had a combination of the two. Only a few patients showed additional ocular motor deficits. Imbalance was observed in all patients except one. Hearing was not affected in any patient during the attack. The findings during acute MV point to central-vestibular dysfunction in 10 patients (50%) and to peripheral vestibular dysfunction in three patients (15%). In the remaining seven patients (35%) the site of involvement could not be determined with certainty. MV should be considered in the differential diagnosis of vertigo with spontaneous and positional nystagmus and can present both as a central and a peripheral vestibular disorder.