Cerebellar hemorrhage in a newborn: a case report in association with suspected arterial dissection of the posterior inferior cerebellar artery.

We herein report a 5-day-old baby boy presented with a massive cerebellar hemorrhage due to suspected posterior inferior cerebellar artery (PICA) dissection. He was born by vacuum extraction at the gestational age of 41 weeks with 3370 g birth weight. On the fifth day of life, he developed dyspnea with worsening vital signs. CT of the head showed massive cerebellar hemorrhage and then transferred to our hospital. External ventricular drainages were emergently placed for his hydrocephalus on the first day of hospitalization, then cerebellar hematoma was evacuated with suboccipital craniotomy on day 11. Under microscopic observation, the left PICA was swollen with dark red discoloration at the caudal loop, being a confirmative finding of arterial dissection. By these findings, we suspected ruptured arterial dissection as a cause of cerebellar hemorrhage. The right PICA looked intact. He required a ventriculoperitoneal shunt on day 59 due to his persistent hydrocephalus, resulting in remarkable improvement of his neurological condition. An MRI, a CT angiography/venography, or blood tests showed no abnormalities such as tumors, vascular anomalies, or coagulopathies. We discuss the significantly rare case of cerebellar hematoma in a newborn, most likely caused by ruptured PICA dissection.