Paraplegia after posterior fossa surgery is a rare and devastating complication. The authors reviewed a case of paraplegia following Chiari decompression and surveyed the literature to identify strategies to reduce the occurrence of such events.
An obese 44-year-old woman had progressive left arm pain, weakness, and numbness and tussive headaches. MRI studies revealed a Chiari I malformation and a cervicothoracic syrinx. Immediately postoperatively after Chiari decompression the patient was paraplegic, with a T6 sensory level bilaterally. MRI studies revealed equivocal findings of epidural hematoma at the site of the Chiari decompression and in the upper thoracic region. Surgical exploration of the Chiari decompression site and upper thoracic laminectomies identified possible venous engorgement, but no hematoma. Subsequent imaging suggested a thoracic spinal cord infarction. Possible explanations for the spinal cord deficit included spinal cord ischemia related to venous engorgement from prolonged prone positioning in an obese patient in the chin-tucked position. At 6.5 years after surgery the patient had unchanged fixed motor and sensory deficits.
Spinal cord infarction is rare after Chiari decompression, but the risk for this complication may be increased for obese patients positioned prone for extended periods of time. Standard precautions may be insufficient and intraoperative electrophysiological monitoring may need to be considered in these patients.