Irreversible Hypoglossal Nerve Injury and Concomitant Trigeminal System Dysfunction After Anterior Surgery to the Cervical Spine: Case Report and Literature Review

The anterior surgical approach to the cervical spine is known to be safe, and damage to the hypoglossal nerve and trigeminal pathway after the surgery is uncommon. However, once damage to those nerves occurs, the patient's quality of life can be severely impaired by discomfort and disability. We report the case of a 59-year-old male with concomitant and irreversible hypoglossal nerve and trigeminal system dysfunction after cervical spine surgery by the anterior approach confirmed by an electrodiagnostic study. He had undergone anterior cervical disc fusion through right-sided approach for a herniated intervertebral disc on the C3-4 level and direct cord compression. He had difficulty with tongue movement, dysarthria, and hypesthesia along the lower margin of the right mandible immediately after the surgery. An electrodiagnostic study revealed hypoglossal neuropathy and trigeminal somatosensory pathway dysfunction. Even though the patient received rehabilitation therapy for impaired tongue movement for more than 2 years, this function did not recover. It is important to be aware of the complexity of the anatomy of vulnerable structures, including hypoglossal nerves and the trigeminal nerve system at the cervical spine level, to prevent damage to important neural structures during surgical procedures.