Bilateral cerebellar infarction in the medial branches of posterior inferior cerebellar arterial territory--using endoscopic third ventriculostomy to relieve acute hydrocephalus.

Simultaneous bilateral cerebellar infarctions in posterior inferior cerebellar arterial (PICA) territory, without brain stem involvement are rare. We herein report a 51-year-old man developed sudden dizziness, nausea and vomiting. CT revealed hypodense bilateral lesions over the cerebellum corresponding to the medial PICA (mPICA) branch territory. His mental state deteriorated 2 days after onset; repeated CT showed severe third and lateral ventricular dilation. Endoscopic third ventriculostomy (ETV) was done to relieve the acute obstructive hydrocephalus. The patient was later discharged with only mild residual ataxia. Compared with conventional surgical treatments (external ventricular drainage, craniectomy and cerebellectomy), ETV has several advantages, including less risk and minimal invasiveness. However, further study is needed on its safety and efficacy under such circumstances.