Electrodiagnostic findings in postoperative C5 palsy after cervical laminectomy and fusion

Abstract Proximal upper extremity weakness is a poorly understood complication of cervical spine surgery. The cause of this complication is unknown, although most patients recover completely over weeks to months with conservative treatment. We present two cases of postoperative, transient clinical C5 palsy after laminectomy and fusion as well as pre- and postoperative electrodiagnostic (EDX) examinations which demonstrate C6 nerve root involvement. EDX studies performed after surgery revealed active denervation of the deltoid and biceps muscles on the symptomatic side. In contrast, the ipsilateral rhomboid muscles appeared unaffected. We suggest that the current models of postoperative C5 palsy pathogenesis may be inadequate to explain our findings and propose an alternative theory of watershed ischemia distal to the origin of the dorsal scapular nerve as a contributing factor to the etiology of this surgical complication. EDX studies may be used to assist with diagnosis, confirm involved root levels, estimate prognosis, to follow recovery or to offer clues into the pathophysiology of the condition.