Supratentorial Intracerebral Hemorrhage after Posterior Fossa Operation

OBJECTIVE Three cases of supratentorial intracerebral hemorrhage after posterior fossa operation are described, and nine other cases reported in the literature are reviewed. The possible causes are discussed, but in eight cases no definite cause could be found. All eight patients were operated on in the sitting position, and all had hematomas in the subcortical white matter. A possible cause might be changes in intracranial dynamics in the sitting position with disruption of subcortical veins. Other authors mention the possibility of occlusion of carotid or vertebral vessels in the neck by improper positioning of the head leading to intraoperative infarction and to hemorrhage within the infarcted brain after repositioning of the patient. With the patient in a lateral or semilateral position, this complication should be preventable.

Limitations of Brain Stem Auditory Evoked Potentials for Intraoperative Monitoring during a Posterior Fossa Operation: Case Report and Technical Note

We have encountered an example of the insensitivity of brain stem auditory evoked potentials (BAEPs) for monitoring the brain stem during a posterior fossa operation. the addition of somatosensory evoked potential recording to conventional BAEP protocols is readily accomplished and is likely to improve the sensitivity of intraoperative electrophysiological assessment of brain stem function.

Air Embolism through a Ventriculoatrial Shunt during Posterior Fossa Operation: Case Report

An unusual complication of air embolism through a ventriculoatrial shunt occurred in a patient undergoing posterior fossa operation in the sitting position. Because ventriculoatrial shunts are uncommon, this potential complication may not be widely recognized. A case is presented and the clinical aspects are discussed. (Neurosurgery 16:83–84, 1985)

Pseudobulbar Palsy after Posterior Fossa Operation in Children

The authors describe their experience with an unusual postoperative syndrome of pseudobulbar palsy occurring a few days after the extirpation of large midline vermian/4th ventricular tumors in children. The patients had a delayed onset of supranuclear cranial nerve palsies associated with emotional incontinence and lability that resolved over several weeks to months. It is postulated that retraction pressure on the medial cerebellum and split vermis is the operative insult responsible for edema that subsequently tracked along fiber pathways in the middle and superior cerebellar peduncles into the upper pons and midbrain. Modifications of operative technique to eliminate the need for retraction are presented.