Large posterior fossa hemorrhage from arteriovenous malformation

Case contributed by Dr Henry Knipe


Sudden collapse at home. No relevant past medical history.

Patient Data

Age: 60 years
Gender: Male

Large posterior fossa hematoma centered within the right cerebellar hemisphere with spread into the subarachnoid and subdural spaces, and further intraventricular spread with hematoma in the trigones of both lateral ventricles.

Significant mass effect with ascending transtentorial herniation and cerebellar tonsil herniation.

Hydrocephalus secondary to complete effacement of the fourth ventricle. Normal aortic arch anatomy.

Located inferiorly to the tentorium cerebelli, just below the torcula in the midline, is an area of abnormal enhancement, consistent with a vascular malformation, with adjacent hemorrhage. Right PICA aneurysm, which is relatively remote from the hemorrhage. 

The patient proceeded to theatre for a decompressive craniectomy, clot evacuation and extraventricular drain insertion. 

Superior right cerebellar hemisphere arteriovenous malformation supplied by right SCA and PICA. Venous drainage is directly into the torcula. Right PICA flow aneurysm. 

Case Discussion

Arteriovenous malformations are not uncommon congenital abnormalities with a rupture risk of ~3% per year. Rebleeding from a ruptured AVM is approximately 20% in 12 months. Flow aneurysms are commonly seen in feeding vessels or within the nidus. 

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Case information

rID: 46361
Published: 4th Jul 2016
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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