A pain in the ear: Two case reports of nervus intermedius neuralgia and narrative review

Abstract

Objective: Present two cases of nervus intermedius neuralgia (NIN) in which patients described unilateral deep ear pain as their primary complaint and present a summary of NIN cases reported in the literature. Background: The nervus intermedius is a tiny branch of the facial nerve that, with neuralgia, can present as a deep ear pain (NIN). The International Classification of Headache Disorders, 3rd edition, (ICHD-3) criteria for an NIN diagnosis include a unilateral deep ear pain with possible radiation that occurs in paroxysms with sharp pain and a tactile trigger. Methods: A PubMed search was conducted for NIN and geniculate neuralgia. Two patients recently diagnosed with NIN at a single clinic were selected for case reports to highlight the variability of symptom presentation. Results: The two cases reported here and the 127 cases reported in the literature show a wider range of presentations than included in the ICHD-3 criteria, including variable pain radiation sometimes diagnosed as concurrent trigeminal, glossopharyngeal, or occipital neuralgia. Pain was reported as constant or paroxysmal, as well as dull, sharp, or neuralgiform with inconsistent presence of triggers. While ICHD-3 does mention reported taste change, lacrimation, and salivation, the literature reports a much wider range of potential features associated with NIN. Optimal medical treatment is unclear given the predominance of surgical reporting of positive response to microvascular decompression, nerve sectioning, or other procedures. The two cases described here were successfully managed medically. Conclusion: NIN can present as described in the ICHD-3, but a more variable presentation may be possible. More studies are needed to clarify presentation, optimal medical treatment, and surgical indications for patients with NIN, especially when patients have no clear neurovascular conflict on neuroimaging. K E Y W O R D S ear pain, geniculate, nervus intermedius, neuralgia, otalgia | 415 HEADACHE How to cite this article: Robblee J. A pain in the ear: Two case reports of nervus intermedius neuralgia and narrative review.

A Rare Case of Idiopathic Painful Nervus Intermedius Neuropathy in a 13-Year-Old Female: A Case Report and Discussion in the Context of the Literature

“…Unfortunately, no established standard medical treatment exists for this condition, and most of the available options derive from treatments of other types of neuropathic pain in adults. From a review conducted on 114 cases of nervus intermedius neuralgia, the pharmacological management with carbamazepine was found to be the most common and effective approach (total of 30 cases; 18/30 good responders), followed by gabapentin (10 cases; 7/10 good responders) [ 2 ]. Both anticonvulsant drugs are widely used for the management of neuropathic pain.…”

“…In case of the failure of a pharmacological approach, surgical interventions, including sectioning of the nervus intermedius, may be considered. This may be performed in conjunction with microvascular decompression of the nervus intermedius and of the adjunct cranial nerves IX and X [ 2 , 3 , 5 , 8 ]. Although those authors that support a surgical option describe a favorable outcome in 90% of the cases, other reports suggest that patients may develop atypical facial pain after an apparently successful surgical intervention [ 20 ].…”

“…The reports available in the literature interchangeably use the terms nervus intermedius neuralgia and geniculate neuralgia when referring to pain with neuropathic characteristics affecting the area innervated by the nervus intermedius. A recent review searching for articles published in PubMed before February 2020 on nervus intermedius neuralgia in the general population reported a total of 102 cases, with a mean age of 44.8 years old and a higher prevalence in females [ 2 ]. As for the etiology, the authors identified neurovascular conflict (48.0% cases, more frequently involving the anterior inferior communicating artery) and infections (10.8%, such as the Ramsay Hunt syndrome and chronic otitis media) as the most frequent causes, among other precipitating factors (30.3%, including masses, myelitis, arachnoid thickening or adhesions or iatrogenic causes).…”

“…As for the etiology, the authors identified neurovascular conflict (48.0% cases, more frequently involving the anterior inferior communicating artery) and infections (10.8%, such as the Ramsay Hunt syndrome and chronic otitis media) as the most frequent causes, among other precipitating factors (30.3%, including masses, myelitis, arachnoid thickening or adhesions or iatrogenic causes). Conversely, 10.8% of the cases were classified as idiopathic [ 2 ].…”

A Rare Case of Idiopathic Painful Nervus Intermedius Neuropathy in a 13-Year-Old Female: A Case Report and Discussion in the Context of the Literature

“…The reports available in the literature interchangeably use the terms nervus intermedius neuralgia and geniculate neuralgia when referring to pain with neuropathic characteristics, affecting the area innervated by the nervus intermedius. A recent narrative review on nervus intermedius neuralgia reported a total of 102 cases with a mean age of 44.8 years old and a higher prevalence in females [2]. As for the etiology, the authors identified neurovascular conflict (48.0% cases) and infections (10.8%) as the most frequent causes, among other precipitating factors (30.3%).…”