Aneurysms from extracranial, extradurally originating posterior inferior cerebellar arteries: a rare case report.

Background: Aneurysms arising from the PICA are infrequent and those arising from an extracranially originating PICA in the extracranial intradural region are even rare. We report a case of bilaterally extracranial extradurally originating PICAs, each of which had an aneurysm, both being situated below the foramen magnum. This to the best of our knowledge is the first of its kind to be reported.