Unilateral Hypoglossal Nerve Palsy in a Patient with a Difficult Airway Requiring Prolonged Intubation.

Isolated cranial nerve injury is a very rare complication of anesthesia. Specifically, hypoglossal nerve palsy affects mobility of the tongue and basic functions of swallowing and speech, and injury can be associated with placement and/or positioning of the endotracheal tube. Many etiologies are described that are unrelated to anesthesia such as tumors, stroke, trauma, or surgical dissection. Identification of hypoglossal neuropraxic-type injury from compression or stretching during anesthetic procedures can be difficult and tends to be a diagnosis of exclusion. Here, we present a case of a unilateral isolated hypoglossal nerve palsy following prolonged intubation in a surgery that involved large fluid shifts resulting in tongue swelling, in which establishment of the airway was initially difficult requiring two attempts. We suggest it is equally as possible that stretch injury occurred during airway instrumentation versus prolonged compression of the nerve between the endotracheal tube and the hyoid bone, possibly relating to a swollen tongue. We outline some treatments that have been used in previous reports and analyze their relation to improvements in symptoms. We conclude that instrumentation of the airway and prolonged intubation are both potential risk factors for hypoglossal nerve palsy, and identification of these risk factors can improve patient care by prompting patient discussions, guiding intraoperative management, and initiating earlier therapies.