Cerebellopontine angle

The cerebellopontine angle is a triangula space at the margin of the cerebellum and pons. The cerebellopontine angle (CPA) is bounded by the tentorium superiorly, brainstem posteromedially and petrous part of temporal bone posterolaterally.

It is an important landmark anatomically and clinically and contents :

• The pontocerebellar cistern

• The facial nerve (CN VII)

• The vestibulocochlear nerve (CN VIII)

• The flocculus of the cerebellum

• The lateral recess of the 4th ventricle

• The anterior inferior cerebellar artery (AICA).

The most common lesions at the cerebellopontine angle are vestibular schwannoma, meningioma, epidermoid tumors, and arachnoid cysts.