CEREBELLAR HERNIATION INTO FORAMEN MAGNUM

Abstract

Any one who has performed a large number of cranial necropsies has been impressed with the frequent finding of a pressure cone of the cerebellum herniated into the foramen magnum in states of increased intracranial pressure. Every neurosurgeon likewise fears this condition and frequently finds the cerebellum wedged into the foramen magnum and extending down into the cervical subarachnoid space. The surgeon, as a matter of routine, taps the ventricle before exploration of the posterior fossa in order to prevent medullary paralysis from a jamming herniation. Despite these common observations, very little information is available as to the clinical frequency of the complication or as to the symptoms and signs of cerebellar herniation. The literature is almost bare of clinical descriptions of this important complication of increased acute or chronic cerebral pressure syndromes. Only a few anatomic reports are to be found. Yet the herniation of the cerebellum into the