Auricular Branch of the Vagus Nerve Innervates the Concha and External Auditory Canal
The vagus nerve (CN X) provides sensory innervation to the concha and external auditory canal of the pinna through its auricular branch, which is the anatomic pathway responsible for referred otalgia in laryngeal cancer. 1
Anatomic Basis for Referred Ear Pain
The vagus nerve serves as the critical link between laryngeal pathology and ear pain through its sensory innervation of specific parts of the external ear:
The auricular branch of the vagus nerve specifically innervates the concha (cavum conchae) and the external auditory canal, providing the anatomic substrate for referred pain from laryngeal malignancies 2, 3
The vagus nerve has the longest course of any cranial nerve, extending from the posterior fossa through the skull base, neck, thorax, and abdomen, making it vulnerable to pathology throughout this trajectory 1, 4
In laryngeal cancer patients, the vagus nerve's dual role in providing motor innervation to laryngeal muscles and sensory innervation to the ear creates the pathway for referred otalgia 1
Clinical Significance in Laryngeal Cancer
Otalgia in the absence of ear pathology should raise immediate suspicion for referred pain from laryngeal or pharyngeal malignancy, particularly in patients with tobacco and alcohol use history 1
The examination finding of ear pain with an unremarkable otoscopic examination strongly suggests referred pain from pharyngeal or laryngeal malignancy rather than primary ear disease 1
Laryngeal cancer patients commonly present with hoarseness or cough as tumor infiltrates the vocal cords, but referred otalgia via the vagus nerve's auricular branch can be a presenting symptom 5
Specific Anatomic Distribution
Nerve profiles are identified between the cartilage and skin in both the cavum conchae and auditory canal, with higher nerve density in the auditory canal compared to the cavum conchae 3
The superior and posterior-inferior segments of the auditory canal contain more numerous nerve fibers than the anterior-inferior segments 3
Pure otalgia localized to the external auditory canal can result from vagus nerve pathology via its auricular branch, and such patients may be misdiagnosed with glossopharyngeal or nervus intermedius neuralgias 2
Diagnostic Implications
A complete head and neck examination with visualization of mucosal surfaces, assessment for neck masses, and palpation of the tongue base is essential when otalgia occurs without obvious ear disease 1
The overlapping sensory innervation of the external auditory canal by cranial nerves VII, IX, and X can lead to diagnostic confusion in patients with otalgia 2