Presentation
Sudden onset headache. No focal neurology ?subarachnoid hemorrhage.
Patient Data
Small intraparenchymal hemorrhage within the right cerebellar hemispehre. No significant mass effect on the fourth ventricle. No hydrocephalus. No subarachnoid hemorrhage.
A cerebellar hemispheric arteriovenous malformation on the right (nidus = 13 mm). It is supplied principally by the enlarged right anterior inferior cerebellar artery but it may be a very small contribution from the left PICA. Drainage is superficial to the superior petrosal sinus with no significant deep venous drainage identified.
MACROSCOPIC DESCRIPTION: A rectangular fragment of brain tissue with attached vessels 10 x 6 x 3mm.
MICROSCOPIC DESCRIPTION: The section shows cerebellar parenchyma in which there is a nidus of vascular channels which extend into the subarachnoid space. These are predominantly venous in type but show an arrangement of elastic fibers within their walls consistent with arterialization. Several small arterial vessels are also seen. The features are consistent with arteriovenous malformation. No evidence of tumor is seen.
DIAGNOSIS: Features consistent with arteriovenous malformation.
Case Discussion
The cerebellar peduncle hemorrhage is an uncommon location for a primary cerebellar bleed (from, for example, hypertension). DSA demonstrated the underlying cause - an arteriovenous malformation.