Otalgia

Secondary Otalgia: Referred Pain Pathways and Pathologies

Otalgia is very common, and when the cause of ear pain is not identified on otoscopy and physical examination, cross-sectional imaging is routinely used to evaluate for potential sources of referred ear pain (secondary otalgia). Innervation of the ear structures is complex, involving multiple upper cervical, lower cranial, and peripheral nerves, which transit and innervate a large anatomic territory involving the brain, spine, skull base, aerodigestive tract, salivary glands, paranasal sinuses, face, orbits, deep spaces of the neck, skin, and viscera. Interpreting radiologists must be familiar with these neural pathways and potential sources of secondary otalgia. The purposes of this review are to detail the currently proposed mechanisms of referred ear pain, review the salient neuroanatomy of the complex pathways responsible for secondary otalgia, highlight important benign and malignant etiologies of referred ear pain, and provide a structured search pattern for approaching these challenging cases on cross-sectional imaging.

Clinical Differences in Types of Otalgia

Background and Objectives

Although otalgia is usually associated with ear problems, it may also originate outside the ear. We therefore assessed the clinical characteristics of patients with otalgia.

Subjects and Methods

We analyzed 294 patients who presented with otalgia. We assessed differences in otalgia between adults and children, differences in otogenic vs. referred otalgia between adults and children, differences between men and women.

Results

Of the 294 patients, 208 (70.7%) had otogenic otalgia and 86 (29.3%) had referred otalgia. Hearing disturbance and otorrhea were significantly more common in otogenic otalgia, whereas rhinorrhea, sore throat, and postnasal drip were significantly more common in referred otalgia. Children were more likely to have otogenic otalgia than adults. The proportion of patients with referred otalgia was significantly higher in adults than in children (p<0.05). Otogenic otalgia was more common in men, whereas referred otalgia was more common in women. Among patients with referred otalgia, neuralgia was significantly more frequent in women than in men (p<0.05).

Conclusions

Otogenic otalgia was more frequent in men than in women and in children than in adults, whereas referred otalgia was more frequent in women and adults, indicating that types of otalgia were dependent on age and gender.

Triggerless neuralgic otalgia: A case series and systematic literature review

Background

Isolated neuralgic pain in the deep ear may arise from either nervus intermedius (NIN) or glossopharyngeal (GPN) neuralgias. Current International Headache Society (IHS) International Classification of Headache Disorders, second edition (ICHD-2) criteria for these cranial neuralgias require the presence of a characteristic trigger.

Aim

The aim of this article is to report cases of triggerless neuralgic otalgia to better understand a subset of patients for whom there may be diagnostic uncertainty.

Methods

Methods included an observational cohort series and systematic literature review.

Results

We identified five female patients with a median age at symptom onset of 58 (range: 47 to 73). Our patients generally experienced an excellent clinical response to carbamazepine. Patients were contacted by telephone at a median follow-up duration of seven years (range: four to 32) from symptom onset, at which time carbamazepine-free remissions were reported by five of five (100%) of the patients. A systematic review of the literature on neuralgic otalgia led us to conclude that NIN was most common among young women (age < 50), and GPN across a wider range of ages of either gender. Among surgically validated cases reported in the literature, triggers were frequently absent in NIN, and variably noted in GPN.

Conclusions

We conclude that the presence of a trigger is not fundamental, and may be impractical, to the diagnosis of neuralgic otalgia, but remains important for specificity between NIN and GPN.

Otalgia

Otalgia, pain in the ear, can be a consequence of otologic disease (primary or otogenic otalgia), or can arise from pathologic processes and structures other than the ear (secondary or referred otalgia). In children, ear disease is far and away the most common cause of otalgia, but in adults, secondary or referred otalgia is more common. Otalgia can be the only presenting symptom of several serious conditions, and its etiology should be fully explored. Unfortunately, its workup is complex and no simple algorithm exists. This article outlines the common causes, presentation, and treatment options for primary and secondary otalgia.

Sectioning the sensory auricular branch of the facial nerve to treat recalcitrant otalgia

OBJECTIVE

To present a new surgical approach to treat idiopathic neuralgia of the sensory auricular branch of the facial nerve.

PATIENTS

: Three patients with chronic ear pain resistant to medical therapy.

INTERVENTION

Sectioning of the sensory auricular branch of the facial nerve along its course at the posterior wall of the external auditory canal by a retroauricular mastoidectomy approach.

MAIN OUTCOME MEASURES

Resolution of otalgia.

RESULTS

All the patients were relieved of their pain at their first follow-up visit, and they have remained symptom-free. The patients were followed at least for 1 year.

CONCLUSION

The surgical treatment of idiopathic otalgia should be reserved for patients in whom medical treatment has failed. Finding the exact location of the ear pain is of utmost importance for a favorable outcome after surgery. If the origin of the otalgia is found to be the sensory auricular branch of the facial nerve, the section of this nerve offers favorable outcomes with no morbidity.

Traumatic neuroma of the tympanic (Jacobson's) nerve as a possible cause of otalgia

OBJECTIVE

To show that traumatic neuroma of the tympanic (Jacobson's) nerve may be a cause of recurrent intractable otalgia in patients following radical mastoidectomies.

STUDY DESIGN

Histologic evaluation of four temporal bones from three patients with a history of recurrent otalgia following radical mastoidectomy.

SUBJECTS AND METHODS

The medical records of three patients with multiple middle ear surgeries in four ears because of recurrent otalgia were reviewed. Histopathologic studies of the four temporal bones were performed.

RESULTS

All four of the temporal bones that underwent multiple surgeries were found to have traumatic neuromas of the tympanic (Jacobson's) nerve.

CONCLUSION

Recurrent otalgia in patients after radical middle ear surgery may be caused by a traumatic neuroma of the tympanic (Jacobson's) nerve.

Cervical spine causes for referred otalgia

Objective

Present experience in diagnosis and treatment for referred otalgia secondary to cervical spine degenerative disease (CSDD).

Study Design

A retrospective study of 123 patients with ear pain.

Subjects and Methods

All patients had a normal otologic examination and diagnosed with unspecified otalgia. The causes for referred otalgia were categorized into Group I: otalgia from non–cervical spine disease (n = 72), and Group II: cervical spine disease–referred otalgia (n = 51). Pain relief following cervical spine physical therapy (CSPT) was assessed. RESULTS: The most common cause for referred otalgia in Group I was Temporomandibular joint (TMJ) dysfunction (46%); most common cervical spine finding in Group II was CSDD (88%). CSPT in those documented patients all reported subjective pain relief.

Conclusion

As the population in America ages, CSDD in the elderly will begin to emerge as a major etiologic source for referred otalgia. With a targeted medical history and physical examination one can use directed studies to diagnose CSDD-referred otalgia, and this pain can be alleviated with CSPT.

Referred otalgia: a structured approach to diagnosis and treatment

Many patients who present with otalgia have a normal otological examination, and a distant source of pain must be considered. The ear receives an extensive sensory innervation arising from six nerve roots. Many other structures in the head, neck and thorax share a common neuronal pathway with the ear, and these tissues represent the possible sites of disease in the cases of referred otalgia. Consequently, the differential diagnosis is extensive and varied. Making an accurate diagnosis relies on an understanding of the complex distribution of nerve fibres and a structured approach to patient assessment. This article aims to classify the aetiology of referred otalgia and to outline current treatments for these conditions. The origins of referred otalgia may be as remote as the cranial cavity and thorax; however, dental disease, tonsillitis, temporomandibular joint disorders and cervical spine pathology represent the most frequent causes. Ear pain may also be the first sign of a head and neck malignancy. Patients complaining of otalgia, with risk factors for an aerodigestive neoplasm, and a normal ENT examination require an urgent otolaryngological opinion.