Spinal cord malfunction after anterior cervical discectomy.

Six cases of myelopathy following anterior operations for removal of disc and fusion of the cervical spine are briefly summarized. Preexisting myelopathy or stenosis of the spinal canal may predispose to this complication. Paralysis may be immediate or delayed for hours. The amount of neural dysfunction is variable, and may fluctuate. Some cases are clearly due to intraoperative trauma caused, for instance, by dowel impaction or by use of the osteotome or drill; some are clearly due to clot. Other more arcane occurrences may be caused by edema, treated with hyperosmotic agents and steroids; or vascular disorder, treated with steroids and a deliberate increase in blood pressure and volume in a manner comparable to the treatment of postangiography or postcraniotomy hemiplegia. In some cases, rough instrumentation in the intervertebral foramen may be implicated. Some cases may be aggravated or induced by manipulation of the neck during intubation or change of position for operation. The risks are calculated as less than 2 per thousand but should be explained to the patient or the patient's family in obtaining consent for operation, since it would appear that even the most careful operation may be followed by this complication.