Review Question - QID 1310

Neurologic deterioration during and after surgery is one of the most serious complications of surgery for cervical compression myelopathy. The earliest article (Yonenobu Spine 1991) looked at 384 patients over 18 years who underwent surgery for cervical myelopathy. Neurologic deterioration was found in 21 patients (5.5%). 13 of these showed signs of C5 root paresis while 8 showed signs of spinal cord dysfunction. While an etiology could be described for 4 of the patients with C5 root paresis (3 graft displacement, 1 hyperextension), the etiology of the remaining 9 was unknown. Even CT myelography could only offer the possible explanation of acute large shift of the spinal cord as being responsible for these defects. Myelograms of 25 patients without neurologic complications showed the maximum cord shift was at C5, but the average shift was not any different from patients with complications. Further studies have corroborated the observances of the 1991 study showing that the C5 root is most affected by postoperative paralysis following posterior cervical decompression. The 2002 paper suggested that in an effort to reduce postoperative C5 nerve root palsy, the clinician should consider intraoperative deltoid and biceps transcranial electrical motor-evoked potential and spontaneous electromyography monitoring whenever there is potential for iatrogenic C5 nerve root injury. They were able to detect injury prospectively and avert more serious consequences with intraoperative monitoring.