Delayed C5 Palsy after Cervical Spine Surgery.

Delayed C5 nerve palsy (C5NP) is a well-known complication of cervical spine surgery and is usually characterized by a benign course with spontaneous improvement over time. While patients-and surgery-specific risk factors have been identified, there is no unifying mechanism to explain the pathogenesis of this condition. The attention toward previous hypotheses faded in favor of a modern multifactorial model integrating anatomic susceptibility, biomechanical, and physiologic changes. Future breakthrough in the management of C5NP will likely come from perioperative neuroprotective pharmacologic protocols and the use of big data analysis and machine learning models to enhance neurophysiological monitoring and postoperative rehabilitation.