Geniculate Neuralgia: A Case Report and Systematic Review

This review discusses the diagnosis and treatment of nervus intermedius neuralgia (NIN) and identifies gaps in the literature. The nervus intermedius is a branch of the facial nerve. NIN presents as a rare neuralgia of this nerve, causing deep ear pain, which may radiate to the auditory canal, auricle, mastoid, soft palate, temple, and angle of the jaw. NIN most commonly presents in middle-aged women; neurovascular compression involving the anterior inferior cerebellar artery is the most common etiology described. Despite its diagnostic criteria in the International Classification of Headache Disorders, 3rd edition (ICHD-3), NIN may lack a trigger zone and may manifest as achy or neuralgiform pain instead of the typically described sharp or shooting pain. Like trigeminal neuralgia, NIN can be divided into classic, idiopathic, secondary, or painful neuropathy. Although there are no established guidelines for treating NIN, many possible treatments are used. Experience from treating trigeminal neuralgia suggests that carbamazepine or oxcarbazepine can be considered first-line. Patients with medically refractory NIN may benefit from neurosurgery referral for microvascular decompression or nerve sectioning. More research is needed to elucidate the range of clinical presentations in patients with NIN. Current data are limited and suggest that symptoms may diverge from the ICHD-3 diagnostic criteria. Although various treatments have been attempted, they often lack solid evidence and are typically derived from approaches used for other neuralgias. Proper diagnosis is crucial, particularly when considering surgical referral, due to the potential overlap of NIN with other neuralgias affecting the head and neck.

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. 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. 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. 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. 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.

Ear canal dynamics

Meningioma in the Middle Ear: An Unusual Case of Hearing Loss

To systematically summarise the peer-reviewed literature relating to the aetiology, clinical presentation, investigation and treatment of geniculate neuralgia. Articles published in English between 1932 and 2012, identified using Medline, Embase and Cochrane databases. The search terms 'geniculate neuralgia', 'nervus intermedius neuralgia', 'facial pain', 'otalgia' and 'neuralgia' were used to identify relevant papers. Fewer than 150 reported cases were published in English between 1932 and 2012. The aetiology of the condition remains unknown, and clinical presentation varies. Non-neuralgic causes of otalgia should always be excluded by a thorough clinical examination, audiological assessment and radiological investigations before making a diagnosis of geniculate neuralgia. Conservative medical treatment is always the first-line therapy. Surgical treatment should be offered if medical treatment fails. The two commonest surgical options are transection of the nervus intermedius, and microvascular decompression of the nerve at the nerve root entry zone of the brainstem. However, extracranial intratemporal division of the cutaneous branches of the facial nerve may offer a safer and similarly effective treatment. The response to medical treatment for this condition varies between individuals. The long-term outcomes of surgery remain unknown because of limited data.

Geniculate neuralgia (GN) is a rare facial pain syndrome characterized by severe stabbing pain in the ear canal. The exact cause of GN remains unclear; however, it is thought that the nervus intermedius (NI) is the primary implicated structure. When medical management fails, surgical interventions are offered to treat the pain. This study aimed to present a consecutive series of patients with GN who underwent craniotomy with NI sectioning, to offer insights into the safety and efficacy of the surgical approach. A retrospective review of consecutive institutional medical records from January 2000 to February 2024 identified patients diagnosed with GN who underwent surgical treatment. Patient records were manually reviewed for information regarding patient demographics, comorbidities, medication history, surgical techniques, and outcomes. The study included 47 NI sectioning procedures in 45 patients with GN (mean age 45.5 years). Most patients had concurrent trigeminal neuralgia (TN) and approximately one-third of patients had concurrent TN and glossopharyngeal neuralgia. Surgical procedures involved NI sectioning, often alongside microvascular decompression (MVD) for cranial nerves (CNs) V or IX/X/XI, with favorable early postoperative pain relief. Of 47 procedures, 38 (80.9%) improved pain (Barrow Neurological Institute [BNI] pain intensity score < IV) and 32 (68.1%) resolved pain (BNI score I) by the latest follow-up visit. There was a low incidence of complications, with 2 cases of unexpected hearing loss among all patients, no instances of permanent facial paralysis, and 1 case of permanent vestibular dysfunction. Additionally, 3 patients reported experiencing loss of taste following surgery. This case series suggests that NI sectioning is safe and likely efficacious in relieving the primary deep ear pain of GN, with a potential additive benefit when performed with MVD on CNs V or IX/X/XI, as needed. Further research is needed to refine treatment guidelines and clarify NI-specific otalgia given the overlapping innervation of the inner ear with other CNs.

The patient’s imaging features, especially the honeycomb pattern of ossific changes in the geniculate fossa, were virtually pathognomonic for ossifying hemangioma of the facial nerve.

INTRODUCTION: Geniculate neuralgia (GN) is a rare pain condition involving the nervus intermedius (NI), a branch of the facial nerve. The current standard for surgical intervention consists of a retrosigmoid craniotomy with sectioning of the NI. However, few case reports/series exist detailing the outcomes of GN surgical treatment. METHODS: We reviewed patient charts involving craniotomies for GN performed by a single surgeon between November 2020 and December 2022. RESULTS: Three patients underwent two craniotomies for GN. GN patients were largely female (91.30%) and White, non-Hispanic/Latino (78.26%). Nearly all GN patients had a concurrent diagnosis of trigeminal neuralgia (n = 22, 95.65%) and some also had a concurrent diagnosis of glossopharyngeal neuralgia (n = 9, 39.13%). Vascular contact with cranial nerves VII and VIII was reported in four procedures. 22 procedures (84.62%) resulted in profound pain relief, with BNI pain score decreasing from 5 to 1 between pre-op and latest follow-up. No patients experienced unexpected hearing loss compared to baseline at latest follow-up. One patient experienced facial paralysis on the side of surgery and two patients experienced some form of vestibular dysfunction at latest follow-up. Of 26 total procedures, 20 included NI sectioning. Initial craniotomies in which the NI was sectioned (n = 18) resolved GN pain 88.89% of the time whereas craniotomies without NI sectioning (n = 5) resolved GN pain 60% of the time. CONCLUSIONS: NI sectioning is an effective means of achieving GN pain relief. Post-operative complications including unexpected hearing loss, facial paralysis, and vestibular dysfunction were infrequently observed in our series.

Symptom: Unilateral Hearing Loss

Ramsay Hunt syndrome is defined as herpes zoster oticus associated with an acute peripheral facial nerve paresis and quite often with other cranial nerve lesions. The combination of motor, sensory and autonomic involvement leads to a variety of neurological damage patterns, i. e. facial muscle paresis, hearing and balance disorders, sensory problems and disturbances of taste as well as lacrimal and nasal secretion. Additional variability of the clinical picture of Ramsay Hunt syndrome is produced by varying patterns of skin involvement explained by individual anastomoses between cranial and cervical nerves. Knowledge of these findings and an early diagnosis of Ramsay Hunt syndrome are important as prognosis of cranial nerve damage depends on the time at which acyclovir-corticosteroid therapy is started.

Geniculate neuralgia (GN) is an uncommon, but severe, condition that is characterized by excruciating paroxysmal pain in the seventh cranial nerve's cutaneous distribution of general somatic afferent fibers carried through the nervus intermedius (NI). GN becomes a surgical disease in refractory cases of pain after exhaustive medical management. Surgical intervention in the form of microvascular decompression and nerve sectioning has been investigated with good patient outcomes. Despite this, there are limited guidelines on either technique's appropriateness in specific operative scenarios. In our 30-year experience in GNs surgical management, we have found that a detailed knowledge of the NIs anatomy, variants, and intraoperative surgical anatomic findings are the key to choosing the most appropriate intervention, and may provide the answer to why some patients fail to experience pain relief after surgery. These anatomic variants also may explain why many patients commonly do not experience side effects related to the visceral efferent and special afferent fibers after nerve sectioning.

Cochlear nerve (CN) aplasia refers to the absence of a visible CN on oblique sagittal magnetic resonance images of the lateral aspect of the inner auditory canal (IAC). Magnetic resonance (MR) is the preferred technique in patients with sensorineural hearing loss and/or vertigo; however, computed tomography (CT) is used to evaluate the IAC or facial nerve canal. Three types of aplasia or hypoplasia can be distinguished (Table 1). A 46-year-old woman came to our ENT consult after being referred for right hearing loss since childhood. There was neither a history of infections nor tinnitus. Otoscopy was normal. Audiometry showed left normoacusia and right profound sensorineural hearing loss. CT scan showed left middle ear normal, with a focal dehiscence in the tympanic portion of the facial nerve, a right middle ear with the ossicles normal, a focal dehiscence in the tympanic portion of the facial nerve and a reduction in the width of the internal auditory canal with normal anterior and posterior labyrinth (Fig. 1). MR was performed to thoroughly evaluate the right inner ear, which confirmed hypoplasia of the cochlear nerve (Figs. 2,3). Cochlear nerve aplasia/hypoplasia can be suspected by CT finding of an internal auditory canal less than 1.5 mm in width because the presence of normal cranial nerves is required for the formation of the IAC and therefore, congenital deficiency of CN VIII (or CN VII) also results in a small or stenotic IAC. It has been reported that IAC stenosis can occur without cochlear nerve hypoplasia; therefore, MR should be performed to detect nerve aplasia or hypoplasia, a challenging diagnosis for the radiologist. In most of the cases, it is associated with profound hearing loss. Nearly all inner ear malformations can be detected on thin-section T2-weighted gradient-echo images or comparable fast spin-echo images. Casselman reported that the cerebellopontine angle should be used as a reference to check the facial and cochlear nerve because he found that the latter was nearly 1 ½-2 times longer than the facial nerve and was never smaller. The nerves are best evaluated and compared on images made perpendicular to the nerves and IAC. This is a case of an adult patient referring to the clinic for right hearing loss since childhood, without ENT evaluation until now. It is important to assess every patient with verified sensorineural hearing loss and no medical history, with radiology tests (CT and MR).

Vagoglossopharyngeal and geniculate neuralgias are less frequently seen types of cranial neuralgias. Their causes and symptomatology are similar to those of trigeminal neuralgia; however, the complex anatomic relationship between the intermedius, vagal, and glossopharyngeal nerves leads to difficulties in the diagnosis and management of neuralgias originating from these cranial nerves. Numerous procedures have been used to treat intractable neuralgias of the VIIth, IXth, and Xth cranial nerves: 1) extracranial sectioning of the cranial nerves, 2) percutaneous thermal rhizotomy, 3) intracranial glossopharyngeal and vagal rhizotomies, 4) microvascular decompression, and 5) percutaneous trigeminal tractotomy-nucleotomy (TR-NC) or nucleus caudalis dorsal root entry zone operation. We propose that computer-guided TR-NC may be the first-choice operation for patients with glossopharyngeal, vagal, or geniculate neuralgia. Nine patients suffering from idiopathic vagoglossopharyngeal neuralgia (six patients) and geniculate neuralgia (three patients) were managed at our clinic. Computed tomography-guided percutaneous trigeminal TR-NC was performed for these nine patients. Excellent (six patients) or good (three patients) pain control was obtained in each patient. Complications included temporary ataxia in two patients after TR-NC. The risk:benefit ratio should be evaluated individually to select the appropriate treatment procedure for patients with vagoglossopharyngeal and geniculate neuralgias. Computed tomography-guided percutaneous TR-NC is an effective and minimally invasive procedure for such patients.

Objective To analyze the clinical characteristics,surgical strategies and effectiveness of nervus intermedius neuralgia.Methods Eighteen patients of nervus intermedius neuralgia admitted to our hospital from September 1999 to August 2009 were analyzed retrospectively.The clinical symptoms,admitting diagnosis,surgical strategies and effectiveness of those patients were compiled and analyzed in combined with literature review.Results All patients of accepted microvascular decompression (MVD).Among them,16 cases' pain completely disappeared after MVD.2 cases had occasional seizures.The total efficiency was 100％.The follow-up lasted 23-60 months (35 months in average).The total efficiency was 100％.The complications,included 3 cases of transient mild facial paralysis and 2 cases of mild hearing dysfunction,were completely relieved within 3 months.Conclusion Nervus intermedius neuralgia was rare.It should be differentiated with other neuralgia diseases,such as trigeminal neuralgia and glossopharyngeal neuralgia.For patients who had poor effect with conservative treatment,MVD was a safe and effective surgical method. Key words: Microvascular decompression; Nervus intermedius neuralgia; Curative effect

Ulnar neuropathy at the elbow (UNE) is the second most common entrapment neuropathy after carpal tunnel syndrome. Treatment may be conservative or surgical, but optimal management remains controversial. This is an update of a review first published in 2011 and previously updated in 2012 and 2016. To determine the effectiveness and safety of conservative and surgical treatment for ulnar neuropathy at the elbow (UNE). We intended to test whether: - surgical treatment is effective in reducing symptoms and signs and in increasing nerve function; - conservative treatment is effective in reducing symptoms and signs and in increasing nerve function; - it is possible to identify the best treatment on the basis of clinical, neurophysiological, or nerve imaging assessment. We searched the Cochrane Neuromuscular Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, four other databases, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform to July 2022. The review included only randomised controlled clinical trials (RCTs) or quasi-RCTs evaluating people with clinical symptoms suggesting the presence of UNE. We included trials evaluating all forms of surgical and conservative treatments. We considered studies regarding therapy of UNE with or without neurophysiological evidence of entrapment. Two review authors independently reviewed titles and abstracts of references retrieved from the searches and selected all potentially relevant studies. The review authors independently extracted data from included trials and assessed risk of bias. We contacted trial investigators for any missing information. The primary outcome was clinically relevant improvement in function compared to baseline. The secondary outcomes of interest were change in neurological impairment, change from baseline of the motor nerve conduction velocity across the elbow, change from baseline in the nerve diameter/cross-sectional area at the elbow, evaluated by ultrasound or MRI, change in quality of life and adverse events. We used GRADE methodology to assess the certainty of evidence. We included 15 RCTs (970 participants), of which six studies were new for this update. Sequence generation was inadequate in one study and not described in six studies; other studies had a low risk of selection bias. We evaluated the clinical outcomes (3 trials, 261 participants) and neurophysiological outcomes (2 trials, 101 participants) of simple decompression versus decompression with submuscular or subcutaneous transposition. Moreover, we evaluated the clinical outcomes of endoscopic versus open decompression surgery (2 trials, 99 participants). We found there was probably little to no difference in clinical improvement in function for simple decompression versus subcutaneous transposition (risk ratio (RR) 0.92, 95% confidence interval (CI) 0.74 to 1.14; 1 study, 147 participants) and simple decompression versus submuscular transposition (RR 0.95, 95% CI 0.77 to 1.17; 2 studies, 114 participants). Compared to simple decompression, we found little to no difference in wound infections for subcutaneous transposition (RR 0.29, 95% CI 0.06 to 1.35; 1 study, 147 participants) and submuscular transposition (RR 0.35, 95% CI 0.10 to 1.21; 2 studies, 114 participants). We found no difference between endoscopic and open decompression in terms of postoperative clinical improvement measured by the Bishop score (RR 0.98, 95% CI 0.84 to 1.14; 2 studies, 99 participants). Among surgical treatments, further single trials investigated postsurgical electrical stimulation after open decompression, nerve decompression and transposition with supercharged end-to-side anterior interosseous nerve-to-ulnar motor nerve transfer. Among conservative treatments for mild or moderate UNE, single trials explored the efficacy of participants' education, night splinting, nerve gliding exercises, corticosteroid and dextrose perineural injection. Low- to moderate-certainty evidence indicates that there is little to no difference in terms of improvement in function or surgical complications between simple decompression and decompression with subcutaneous or submuscular transposition in idiopathic UNE, including when the nerve impairment is severe. Moderate-certainty evidence indicates that there is little to no difference between endoscopic and open decompression in improving clinical function and in terms of procedural complications. Very low-certainty evidence indicates that it is unclear if steroid injections have an effect on clinical improvement, compared to placebo, and if written instructions have an effect on clinical improvement, compared to surgical decompression. Findings from a small RCT on conservative treatment showed that in mild cases, information on movements or positions to avoid may reduce subjective discomfort. One RCT showed that dextrose injection might reduce pain at either short-term (four months) or long-term follow-up (12 months), compared to placebo. Another RCT did not show differences in clinically relevant improvement between dextrose and corticosteroid injection. In clinically severe UNE, findings from a small RCT showed that postsurgical electrical stimulation improves intrinsic muscle reinnervation and strength at 12 months' follow-up.