Abstract
We report on two cases of cerebellar infarction in the territory of the medial branch of the posterior inferior cerebellar artery (mPICA) mimicking acute peripheral vertigo. Case 1 was a 54-year-old man with WPW syndrome presenting with sudden vertigo. When he was admitted to our hospital, he had direction fixed horizontal nystagmus towards the left. His symptom disappeared in several days, however, MRI revealed a haemorrhagic infarct in the territory of the right mPICA. Case 2 was a 47-year-old man who was admitted with sudden rotatory vertigo. Direction fixed horizontal nystagmus towards the right was noted and head CT was normal. The nystagmus disappeared on the 5th day of the illness and caloric testing did not show canal paresis. Because of prolonged gate ataxia, a CT scan was performed again. It showed a cerebellar infarction and MRI revealed a cerebellar infarction of the left medial hemisphere and vermis. Infarcts of mPICA sometimes cause acute vertigo presenting horizontal direction fixed nystagmus mimicking peripheral vertigo. In a patient presenting with acute vertigo, head MRI should be performed when he or she has history of risk factor for cerebellar infarction such as diabetes mellitus, ischemic heart disease, and so on. The patients with prolonged ataxia and headache should also undergo MRI.
