We reported the cases of migraine with cerebellar ataxia accompanied by vertical nystagmus to downward in a right lateral position. Usually we investigated the positional nystagmus by means of electronystagmography with the eye opened under Frenzel's glasses in the dark.
Both cases are father and son aged 60 and 29, had an attack of a migraine and cerebellar ataxia in their middle ages. Similar symptoms and signs are proved in 5 persons among their family. We emphasized the clinical significance of vertical nystagmus in neurotological examinations, while the literature of such nystagmus findings is rare.