Spontaneous healing and complete disappearance of a ruptured posterior inferior cerebellar artery dissecting aneurysm.

A 7-month-old baby presented with a 4-day history of drowsiness and vomiting after a falling accident. Magnetic resonance imaging demonstrated diffuse subarachnoid hemorrhage, intraventricular hemorrhage, and variable stages of subdural hematoma in bilateral occipital and left temporal subdural spaces. A partially thrombosed aneurysm was noted in the right craniocervical junction. Ophthalmological examination revealed bilateral retinal petechial hemorrhages. Conventional cerebral angiography revealed a dissecting aneurysm in the right posterior inferior cerebellar artery (PICA). Endovascular embolization was suggested, but the family refused. After conservative treatment, follow-up MRI revealed that the PICA aneurysm had remodeled and ultimately disappeared completely at the 10th month. This case illustrates the relatively plastic nature of intracranial aneurysms in pediatric patients. More studies are necessary to clarify the natural history of spontaneously thrombosed aneurysms to assist in their overall management.