Paralysis Caused by Spinal Cord Injury After Posterior Fossa Surgery: A Systematic Review

OBJECTIVE: Paralysis (paraplegia or quadriplegia) after posterior fossa surgery is a rare but devastating complication. We investigated previous reports of this complication to examine similarities among patients, risk factors, and methods by which it may be prevented. METHODS: A systematic review was completed according to PRISMA guidelines. Electronic databases were searched until November 2019 using keywords "paraplegia," "quadriplegia," or "spinal cord injury" added to "posterior fossa surgery." RESULTS: Thirteen case reports published between 1996 and 2019 were included. Five (38.5%) involved quadriplegia/quadriparesis and 8 (61.5%) involved paraplegia after surgery. Ten cases (76.9%) were tumor resections and 3 (23.1%) were posterior fossa decompressions (2 for Chiari malformations and 1 for Morquio syndrome). Seven surgeries (53.8 degrees/0) were performed in the sitting position and 6 (46.2%) were prone. Proposed mechanisms of paralysis involved cervical hyperflexion yielding spinal cord ischemia in 8 patients (61.5%), arterial hypotension in 2 patients (15.4%), spinal cord compression from hematoma in 1 patient (7.7%), and decreased cardiac output in 1 patient (7.7%) (1 study did not propose a cause). Cervical hyperflexion was equally likely in the sitting and prone positions (4 patients each). Only 3 patients (23.1%) involved intraoperative complications (all cardiopulmonary in nature). CONCLUSIONS: Paralysis after posterior fossa surgery often involves spinal cord infarction apparently caused by cervical hyperflexion. Extreme care during patient positioning is needed in both the sitting or prone positions. Electrophysiologic monitoring might enable early identification of spinal cord dysfunction to minimize or avoid this complication.