Review Question - QID 492

A C5 palsy (deltoid and biceps weakness) is the most likely neurologic complication following cervical laminoplasty, with an incidence of ~5%. Its pathogenesis and the options for prevention and treatment remain unidentified and many controversies exist. Two theories to account for the pathogenesis of C5 palsy exist: 1) nerve root injury 2) segmental spinal cord disorder. Neither of these hypotheses has been consistently supported and evidence to refute each hypothesis can be found in the literature. Although patients with C5 palsy generally have a good prognosis for neurologic and functional recovery, those with severe paralysis require significantly longer recovery times when compared to more mild cases.

Sakaura et report a 4.6% incidence of postoperative C5 palsy. They found no significant difference between patients undergoing anterior decompression and fusion and posterior laminoplasty. There was also no difference between cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament.

Chiba et al found the pattern of delayed onset of paralysis, dysesthesia in the upper extremities, and the presence of T2 high-signal intensity zones suggest that a certain impairment in the gray matter of the spinal cord may play an important role in the development of postoperative segmental motor paralysis.

Kaneko et al attempted to investigate the possible mechanism for postoperative motor dominant C5 paralysis from intraoperative electrophysiological studies. They found a 7.6% incidence of postoperative motor dominant C5 paralysis. C5 paralysis occurred from 1 to 3 days after surgery and compromised unilaterally in all 5 patients. They were unable to draw significant conclusions regarding the etiology.

Incorrect Answers:
Answer 1: Change in voice and difficulty swallowing is associated with a recurrent laryngeal nerve injury, which is associated with anterior procedures and not a posterior laminoplasty.
Answer 2: Although a C7 palsy (triceps weakness) is a possible complication of a laminoplasty, a C5 palsy is more common.
Answer 3: A hypoglossal nerve injury is a rare complication of anterior cervical surgery and results in deviation of the tongue
Answer 4: Horner's syndrome is a rare complication of anterior cervical surgery, and presents with ptosis, miosis, and anhidrosis.