[Acute vestibular syndrome in cerebellar infarct of the posterior inferior cerebellar artery (PICA infarct)].

The differential diagnosis of an acute peripheral vestibulopathy ("vestibular neuritis") and of an ischemic lesion in the cerebellar territory of the posterior-inferior cerebellar artery (PICA) is important. Both present with acute vertigo, vomiting, spontaneous nystagmus and difficulties in walking. We analyze the clinical, oculographic and NMR findings as well as the outcome in 10 patients with an ischemic stroke in the cerebellar territory of the PICA. On clinical grounds alone, it is not always possible to attribute the acute vestibular syndrome to a peripheral vestibular lesion or to a PICA insult. In our experience an important feature of a PICA insult is a discrepancy between the amount of vertigo, the severity of the walking difficulties, and the often weak and rapidly resolving spontaneous nystagmus. In contrast to a peripheral vestibulopathy, the vestibuloocular reflex is only minimally or not decreased in PICA insults, and gain asymmetries are accounted for by the presence of spontaneous nystagmus. However, only neuroimaging can finally differentiate between the two entities.