C-5 palsy after cerebrospinal fluid diversion in posttraumatic syringomyelia: case report.

Syringomyelia is a potentially debilitating disease that involves abnormal CSF flow mechanics; its incidence after traumatic spinal cord injury (SCI) is approximately 15%. Treatment consists of restoration of CSF flow, typically via arachnoidolysis and syrinx decompression. The authors present a case of pronounced syringomyelia in a patient with concomitant severe cervical myelomalacia to demonstrate unilateral C-5 palsy as a potential complication of aggressive syrinx decompression at a remote level. A 56-year-old man with a remote history of SCI at T-11 (ASIA [American Spinal Injury Association] Grade A) presented with complaints of ascending motor and sensory weakness into the bilateral upper extremities that had progressed over 1 year. MRI demonstrated severe distortion of the spinal cord at the prior injury level of T10-11, where an old anterior column injury and prior hook-rod construct was visualized. Of note, the patient had a holocord syrinx with demonstrable myelomalacia. To restore CSF flow and decompress the spinal cord, T-2 and T-3 laminectomies, followed by arachnoidolysis and syringopleural shunt placement, were performed. Postoperatively on Day 1, with the exception of a unilateral deltoid palsy, the patient had immediate improvement in upper-extremity strength and myelopathy. He was discharged from the hospital on postoperative Day 5; however, at his 2-week follow-up visit, a persistent unilateral deltoid palsy was noted. MRI demonstrated a significant reduction in the holocord syrinx, no neural foraminal stenosis, and a significant positional shift of the ventral spinal cord. Further motor recovery was noted at the 8-month follow-up. Syringomyelia is a debilitating disease arising most often as a result of traumatic SCI. In the setting of myelomalacia with a pronounced syrinx, C-5 palsy is a potential complication of syrinx decompression.