Hypoglossal nerve palsy after airway management for general anesthesia: an analysis of 69 patients

Abstract

Isolated hypoglossal nerve palsy (HNP), or neurapraxia, a rare postoperative complication after airway management, causes ipsilateral tongue deviation, dysarthria, and dysphagia. We reviewed the pathophysiological causes of hypoglossal nerve injury and discuss the associated clinical and procedural characteristics of affected patients. Furthermore, we identified procedural factors potentially affecting HNP recovery duration and propose several measures that may reduce the risk of HNP. While HNP can occur after a variety of surgeries, most cases in the literature were reported after orthopedic and otolaryngology operations, typically in males. The diagnosis is frequently missed by the anesthesia care team in the recovery room due to the delayed symptomatic onset and often requires neurology and otolaryngology evaluations to exclude serious etiologies. Signs and symptoms are self-limited, with resolution occurring within 2 months in 50% of patients, and 80% resolving within 4 months. Currently, there are no specific preventive or therapeutic recommendations. We found 69 cases of HNP after procedural airway management reported in the literature from 1926 to 2013.

Figure 1

Non-contrast computed tomography (CT) scan of the neck in a patient with hypoglossal nerve palsy (HNP). Asymmetric heterogeneous soft tissue swelling in the right anterolateral oropharynx, marked with an asterix (*), extending from base of the tongue to vallecula, is seen on the coronal section.

Figure 2

Anatomic locations for hypoglossal nerve injury during airway management. (1) Nerve compression or impingement can occur at the hyoid bone where the nerve is relatively superficial in its course. ^{, , , , ,} (2) Nerve stretching can occur at the lateral aspect of the transverse process of the first cervical vertebrae (C1). (3) Pressure exerted by the laryngoscope blade can lead to lateral retraction and shearing of the distal nerve fibers that supply motor input to the tongue. (4) A calcified stylohyoid ligament has also been reported in association with hypoglossal nerve impingement. Drawing courtesy of Dr. C. Barnes.

Figure 3

Figures 3a–c. Distribution of hypoglossal nerve palsy (HNP) diagnoses. Gender (a), airway type (b), and surgery type (c) subgroups are separately delineated within each stacked column. Patients of male gender or those receiving an endotracheal tube composed the majority of reported hypoglossal neurapraxia cases. Twelve of 25 (48%) otolaryngology operations and 4 of 8 (50%) cardiac surgeries were associated with multiple cranial nerve palsies. LMA = laryngeal mask airway; ETT = endotracheal tube.

Figure 3

Figures 3a–c. Distribution of hypoglossal nerve palsy (HNP) diagnoses. Gender (a), airway type (b), and surgery type (c) subgroups are separately delineated within each stacked column. Patients of male gender or those receiving an endotracheal tube composed the majority of reported hypoglossal neurapraxia cases. Twelve of 25 (48%) otolaryngology operations and 4 of 8 (50%) cardiac surgeries were associated with multiple cranial nerve palsies. LMA = laryngeal mask airway; ETT = endotracheal tube.

Figure 4

Time-to-event curve demonstrating hypoglossal nerve palsy (HNP) recovery status based on airway management device. A vertical dash (|) represents patients with persistent tongue deviation (no recovery) at the time of follow-up reported in each individual case report; these patients are right-censored as their recovery status after the reported follow-up period is unknown. The x-axis describes the number of days after airway removal until the reported follow-up in each individual case study. The y-axis describes the cumulative recovery represented as the number of patients with a positive recovery status at any follow-up interval divided by the total number of patients in the subgroup. One patient who received Combitube was excluded from the airway subgroup analysis. LMA = laryngeal mask airway; ETT = endotracheal tube.

Appendix Figure 1

Literature search results for hypoglossal nerve palsy (HNP) after procedural airway management. The subgroups of combined neurapraxias, in addition to solitary HNP, and their respective patient counts are listed. * schwannoma resections, parapharyngeal/carotid body tumor resections, neck dissections, carotid endarterectomies and reconstructive procedures, neck dissections and parathyroid excisions.^s33–s77