Can cervical spine injury cause diminished laryngeal mucosal sensations?

Laryngeal Mucosal Sensation Impairment Following Cervical Spine Injury

Yes, cervical spine injuries can cause diminished laryngeal mucosal sensations, which may significantly impact airway protection mechanisms and increase the risk of aspiration.

Pathophysiological Mechanisms

• Cervical spine injuries, particularly those affecting the upper cervical levels (C2-C5), can compromise neural pathways that innervate the larynx, leading to sensory deficits in the laryngeal mucosa 1
• The superior laryngeal nerve (SLN), which provides sensory innervation to the laryngeal mucosa, can be affected by cervical spine trauma either directly or through associated swelling and inflammation 2
• Injuries at C5 level specifically impact respiratory function and can lead to ineffective clearance of secretions, which may further compromise laryngeal sensation through chronic irritation 1

Clinical Implications

• Diminished laryngeal mucosal sensation increases the risk of silent aspiration, as the protective cough reflex may be impaired or absent 1
• Patients with cervical spine injuries often demonstrate reduced ability to generate adequate expiratory pressures needed for effective cough, compounding the problem of impaired laryngeal sensation 1
• The combination of sensory deficits and motor impairment can significantly increase morbidity and mortality due to respiratory complications 1

Mechanisms of Injury

• Direct trauma to the recurrent laryngeal nerve or superior laryngeal nerve during cervical spine injury 3
• Compression of the recurrent laryngeal nerve within the endolarynx due to displacement of anatomical structures following trauma 3
• Stretch-induced nerve injury, particularly affecting the right recurrent laryngeal nerve which has less redundancy in its anatomical course 4
• Secondary effects from surgical interventions for cervical spine injuries, such as anterior cervical spine surgery, which can cause temporary or permanent vocal fold paralysis 3

Risk Factors for Laryngeal Sensory Impairment

• Higher cervical spine injuries (C2-C5) pose greater risk to laryngeal sensory function than lower cervical injuries 1
• Right-sided approaches in anterior cervical spine surgeries carry higher risk of recurrent laryngeal nerve injury due to anatomical differences in nerve course 4
• The presence of pre-existing airway pathology or cricoid cartilage involvement increases the risk of sensory complications 5
• Prolonged intubation following cervical spine injury may contribute to laryngeal sensory deficits 6

Management Considerations

• Early assessment of laryngeal sensory function should be performed in patients with cervical spine injuries, particularly those affecting upper cervical levels 1
• Videolaryngoscopy is recommended for airway management in patients with suspected or confirmed cervical spine injury to minimize further trauma 7
• A bundle approach including active physiotherapy and mechanically-assisted insufflation/exsufflation devices is recommended to facilitate respiratory management 1
• When performing airway management in patients with cervical spine injuries, manual in-line stabilization is preferred over rigid collar immobilization to improve visualization and reduce the risk of further nerve injury 8

Prevention Strategies

• During surgical interventions, monitoring endotracheal tube cuff pressure and releasing pressure after retractor placement may help prevent injury to the recurrent laryngeal nerve 3
• Early implementation of respiratory protocols including bronchial drainage physiotherapy can improve outcomes and potentially reduce the impact of sensory deficits 1
• Careful surgical technique during anterior cervical approaches, particularly when exposing more rostral levels of the cervical spine, may decrease the risk of SLN injury 2

Special Considerations

• In emergency situations involving patients with cervical spine injuries and potential laryngeal sensory deficits, standard emergency front-of-neck airway access techniques may be complicated 5
• Ultrasound guidance should be considered to identify and mark the cricothyroid membrane before attempting any emergency airway intervention in these patients 5
• A multidisciplinary approach involving spine surgeons, otolaryngologists, and speech pathologists is essential for comprehensive management of patients with laryngeal sensory deficits following cervical spine injury 5