Vagus Nerve Innervates the Ear in Laryngeal Cancer-Related Referred Otalgia
The vagus nerve (CN X) is responsible for referred pain to the ear in laryngeal cancer, and it provides general sensory innervation to the ear. 1
Anatomic Basis for Referred Otalgia
The vagus nerve supplies visceral sensation to the pharynx, larynx, and viscera, as well as general sensation to the ear. 1 This sensory branch to the ear is the anatomic pathway through which laryngeal pathology—such as the vocal cord mass with subglottic extension described in this case—causes referred otalgia. 1
Key Clinical Points:
The vagus nerve has the longest course of any cranial nerve in the body, running from the posterior fossa through the skull base, neck, thorax, and into the abdomen, making it vulnerable to pathology throughout this entire trajectory. 1
Branchial motor branches of the vagus innervate laryngeal muscles via the superior and recurrent laryngeal nerves, while its sensory branches provide general sensation to the ear. 1
In patients with upper aerodigestive tract cancer (including laryngeal cancer), otalgia in the absence of ear pathology should raise suspicion for referred pain from the larynx or pharynx. 1
Clinical Significance in This Case
This 50-year-old man with laryngeal cancer involving both vocal cords and subglottic extension likely experiences referred ear pain through the auricular branch of the vagus nerve. 1 The examination finding of otalgia with an unremarkable ear examination (normal pinna, external auditory canal, and tympanic membrane) suggests referred pain from pharyngeal or laryngeal malignancy. 1
Common Pitfall to Avoid:
Do not assume ear pain in a patient with hoarseness and respiratory symptoms is due to primary ear pathology. 1, 2 A complete head and neck examination with visualization of mucosal surfaces, assessment of neck masses, and palpation of the tongue base is essential when otalgia occurs without obvious ear disease, particularly in patients with tobacco and alcohol use history. 1
Differential Considerations for Referred Otalgia
While the vagus nerve is the primary pathway in laryngeal cancer, other cranial nerves can cause referred otalgia from different sources: 2
- Trigeminal nerve (CN V): Temporomandibular joint syndrome, dental pathology 1, 2
- Glossopharyngeal nerve (CN IX): Oropharyngeal pathology, glossopharyngeal neuralgia 3, 2
- Spinal nerves C2-C3: Cervical spine pathology 2
However, in the context of laryngeal cancer with vocal cord involvement, the vagus nerve is the responsible pathway for referred otalgia. 1