Cranial neuralgias: from physiopathology to pharmacological treatment

Prognostic factors for long-term outcomes of microvascular decompression in the treatment of glossopharyngeal neuralgia: a retrospective analysis of 97 patients

OBJECTIVE

The authors aimed to investigate predictors of postoperative outcomes of microvascular decompression (MVD) for the treatment of glossopharyngeal neuralgia (GPN).

METHODS

A cohort of 97 patients with medically refractory GPN who underwent MVD at the authors' institution between January 2010 and July 2019 was retrospectively reviewed. Univariate and multivariate regression models were used to identify predictors of long-term outcome in patients after MVD.

RESULTS

Eighty-nine patients (91.8%) reported immediate and complete relief of pain after the procedure. Of the remaining 8 patients (8.2%), 6 achieved partial pain relief and pain gradually diminished within 2 weeks after surgery, and 2 did not experience postoperative pain relief. In univariate Cox regression analysis, venous compression of the glossopharyngeal nerve root entry zone (HR 3.591, 95% CI 1.660-7.767, p = 0.001) and lower degree of neurovascular conflict (HR 2.449, 95% CI 1.177-5.096, p = 0.017) were significantly associated with worse pain-free survival. In multivariate Cox regression analysis, venous compression (HR 8.192, 95% CI 2.960-22.669, p < 0.001) and lower degree of neurovascular conflict (HR 5.450, 95% CI 2.069-14.356, p = 0.001) remained independently associated with worse pain-free survival.

CONCLUSIONS

Venous compression of the glossopharyngeal nerve root entry zone and lower degree of neurovascular conflict were significantly correlated with shorter pain-free survival in patients who underwent MVD for GPN. Microvascular decompression is a safe, feasible, and durable approach with a low complication rate for the treatment of GPN.

Glossopharyngeal Neuralgia Associated With Bradycardia and syncope—a Case Report

We describe a case of 76-year-old woman with glossopharyngeal neuralgia who developed bradycardia and syncope after decreased carbamazepine dosing due to worsening renal function. Telemetry and EKG showed bradycardia and sinus pauses associated with paroxysms of typical glossopharyngeal neuralgia pain. With the addition of gabapentin to carbamazepine, her glossopharyngeal neuralgia pain as well as bradycardia resolved. A pacemaker was placed to prevent bradycardia and syncope. Clinicians should be mindful of the association between glossopharyngeal neuralgia and bradycardia and cardiac syncope so appropriate treatment can be offered in a timely manner to prevent adverse outcomes associated with syncope and cardiac arrest.

The Diagnosis and Management of Posttraumatic Headache with Associated Painful Cranial Neuralgias: a Review and Case Series

BACKGROUND

Cranial neuralgias are common in the setting of posttraumatic headache. They may exacerbate underlying primary headache disorders and therefore may be overlooked in clinical practice. Frequently, cranial neuralgias generate neuropathic symptoms such as lancinating pain and sensory dysesthesias. Cranial neuralgias are identified based on a clinical history of focal neuropathic pain and physical exam findings including tenderness with palpation and percussion, at times eliciting radiating pain or paresthesias in the corresponding sensory nerve distribution.

PURPOSE OF REVIEW

This article is a brief review of the literature and a retrospective report of 2 cases of posttraumatic headache with associated painful cranial neuralgias.

RECENT FINDINGS

Two patients presented with headaches that met criteria for posttraumatic headache, but their history and physical examination suggested the presence of a focal painful cranial neuralgia. One patient was diagnosed with auriculotemporal neuralgia, which was exquisitely responsive to an auriculotemporal nerve block. The second patient was diagnosed with supratrochlear neuralgia, which was effectively treated with a supratrochlear nerve block. In both cases, adequate treatment of the painful cranial neuralgia resulted in significant improvement of the baseline PTH. Painful cranial neuralgias frequently occur within the clinical spectrum of posttraumatic headache, but are often undiagnosed. Treatment options for painful cranial neuralgias are often different than those traditionally employed for posttraumatic headache without cranial neuralgias, which can include peripheral nerve blockade, neuropathic medications, and in refractory cases, peripheral nerve decompression surgery.

Paroxysmal otalgia treated with microvascular decompression of the intermediate nerve: illustrative case

BACKGROUND

Intermediate nerve neuralgia is a rare type of cranial neuralgia that causes clinical, therapeutic, and diagnostic challenges. Studies have described pharmacological and surgical treatment options. Surgical treatment ranges from sectioning of neural structures to microvascular decompression. Given the rareness of the disease, there are no clear recommendations concerning treatment.

OBSERVATIONS

Reported is the case of a patient with typical intermediate nerve neuralgia. In this particular case, decision-making toward surgical decompression in an earlier stage of the disease could have been beneficial. The authors found excellent results using only microvascular decompression without sectioning of neural structures.

LESSONS

Knowledge of intermediate nerve anatomy is essential to understand this complex pain syndrome. This case illustrates that surgery should not only be regarded as a last resort in case of failure of conservative treatment but also should be considered early in the disease course, especially in the case of a clear neurovascular conflict. When no evident cause is found, surgery could be considered as an exploratory option to depict a neurovascular conflict intraoperatively. Microvascular decompression of the intermediate nerve without sectioning of neural structures can obtain excellent results. Since neural structures are saved, postoperative sequelae can be limited.

Course of Concomitant Bell's Palsy and Trigeminal Neuralgia Shortened with a Multi-Modal Intervention: A Case Report

A 60-year-old man presented to the ER with lancinating right-sided facial pain following a URI. He was diagnosed with trigeminal neuralgia, yet returned several days later with right-sided facial paralysis. He was then also diagnosed with Bell's palsy and treated with corticosteroids and antiviral medication. He continued to experience facial pain and paralysis, and sought out integrative medical care including acupuncture, nutritional supplements, diet and lifestyle changes, and parenteral therapy with intravenous vitamins and minerals. Eight weeks later he reported near complete resolution of symptoms. Multi-modal interventions may shorten recovery time in some patients with trigeminal neuralgia or Bell's palsy. To the best of our knowledge, this is the first case report on concomitant trigeminal neuralgia and Bell's palsy. The CARE (CAse REport) guidelines were used in the writing of this case report.

Postherpetic Neuralgia and Trigeminal Neuralgia

Postherpetic neuralgia (PHN) is an unpredictable complication of varicella zoster virus- (VZV-) induced herpes zoster (HZ) which often occurs in elderly and immunocompromised persons and which can induce psychosocial dysfunction and can negatively impact on quality of life. Preventive options for PHN include vaccination of high-risk persons against HZ, early use of antiviral agents, and robust management of pain during the early stage of acute herpes zoster. If it does occur, PHN may persist for months or even years after resolution of the HZ mucocutaneous eruptions, and treatment is often only partially effective. Classical trigeminal neuralgia is a severe orofacial neuropathic pain condition characterized by unilateral, brief but recurrent, lancinating paroxysmal pain confined to the distribution of one or more of the branches of the trigeminal nerve. It may be idiopathic or causally associated with vascular compression of the trigeminal nerve root. The anticonvulsive agents, carbamazepine or oxcarbazepine, constitute the first-line treatment. Microvascular decompression or ablative procedures should be considered when pharmacotherapy is ineffective or intolerable. The aim of this short review is briefly to discuss the etiopathogenesis, clinical features, and treatment of PHN and classical trigeminal neuralgia.

Glossopharyngeal neuralgia associated with cardiac syncope

Glossopharyngeal neuralgia is a rare pain syndrome presenting with paroxysms of pain in the region of the glossopharyngeal nerve. Even more uncommon is the association between glossopharyngeal neuralgia and cardiac syncope. In these patients, the cardiovascular consequences may include bradycardia, hypotension and cardiac arrest. We describe the case of a 40-year-old patient who presented with this rare association of glossopharyngeal neuralgia and syncope. Multiple pauses including one lasting 14 s were noted on ambulatory ECG monitoring. In this case, the patient declined pharmacological treatment with carbamazepine or with permanent pacing and so far has been in remission from symptoms for 3 months.

Current neurosurgical management of glossopharyngeal neuralgia and technical nuances for microvascular decompression surgery

Glossopharyngeal neuralgia (GPN) is an uncommon facial pain syndrome often misdiagnosed as trigeminal neuralgia. The rarity of this condition and its overlap with other cranial nerve hyperactivity syndromes often leads to a significant delay in diagnosis. The surgical procedures with the highest rates of pain relief for GPN are rhizotomy and microvascular decompression (MVD) of cranial nerves IX and X. Neurovascular conflict at the level of the root exit zone of these cranial nerves is believed to be the cause of this pain syndrome in most cases. Vagus nerve rhizotomy is usually reserved for cases in which vascular conflict is not evident. A review of the literature reveals that although the addition of cranial nerve X rhizotomy may improve the chances of long-term pain control, this maneuver also increases the risk of permanent dysphagia and vocal cord paralysis. The risks of this procedure have to be carefully weighed against its benefits. Based on the authors' experience, careful patient selection with a thorough exploratory operation most often leads to identification of the site of vascular conflict, obviating the need for cranial nerve X rhizotomy.

Cranial neuralgias

This article describes the clinical findings of cranial neuralgias, such as trigeminal neuralgia, glossopharyngeal neuralgia, nervus intermedius neuralgia, and others, and postherpetic neuralgia. Pathophysiology of these neuralgias, diagnostic methods, and treatment are also discussed. This information will enable the dentist to diagnose patients who have these rare conditions.

Use of single- and multi-drug regimens in the management of classic (idiopathic) trigeminal neuralgia: an 11-year experience at a single Sri Lankan institution

AIM

The aim of this retrospective study was to evaluate the outcome of medical treatment of classic trigeminal neuralgia and to assess the factors affecting the choice of drug regimen (single or multiple), and the duration of treatment for pain control.

METHODS

A total of 260 consecutive patients were included in the study. Sixty-one patients with less than 6 months' follow up were excluded. All patients were treated with carbamazepine alone or in combination with other drugs. The dosage was adjusted according to the level of pain control and side-effects.

RESULTS

Treatment was terminated in 99 patients (49.7%) after a mean follow-up period of 36.46 months (standard deviation: ±26.5). Of these, 39.4% were on a single drug. Carbamazepine was the drug used in 36 patients. The rest (61%) needed various combinations of drugs. One-hundred patients (50.3%) continued with medical treatment during the follow-up period. Of these, 67.4% were on multi-drug therapy.

CONCLUSION

The present study showed that the administration of multidrug regimens is a useful alternative in controlling trigeminal neuralgia in patients who are unable to tolerate higher doses of carbamazepine. Age, sex, ethnicity, and the side of affliction did not have a significant influence on the choice of drug regimen and the duration of treatment for pain control.

Tonsillolithiasis and orofacial pain

Tonsilloliths are rare calcified structures that usually result from chronic inflammation of the tonsils. Concretions show differences in size, shape and colour. They are usually asymptomatic but can be associated with halitosis, foreign body sensation, dysphagia and odynophagia, otalgia, and neck pain. A patient was referred because panoramic radiography performed by a general dentist revealed radiopaque shadows over the ascending rami of the mandible, located bilaterally: a solitary structure on the higher portion of the right side and two small structures on the left side. Paroxysmal attacks of orofacial pain and symptoms such as dysphagia and swallowing pain on the left side distributed within the tonsillar fossa and pharynx and the angle of the lower jaw were present. The computed tomography images revealed bilateral tonsilloliths. Clinically, there was no sign of inflammation, and the patient's past history revealed an approximately 2-year history of dysphagia, swallowing pain and left-sided neck pain. At the request of the patient, no surgical intervention was carried out. Glossopharyngeal neuralgia is a rare entity, and the aim of this report was to indicate the importance of tonsilloliths as a cause of orofacial pain.

Update on trigeminal neuralgia

Trigeminal neuralgia leads to paroxysms of short-lasting but very severe pain. Between attacks, patients are usually asymptomatic, but a constant dull background pain may persist in some cases. The incidence of trigeminal neuralgia is 4.3 per 100,000 persons per year, with a slightly higher incidence for women (5.9 per 100,000) compared with men (3.4 per 100,000). There is a lack of certainty regarding the etiology and pathophysiology of trigeminal neuralgia. There are a wide range of medical and surgical treatments available. The preferred medical treatment for trigeminal neuralgia consists of anticonvulsant drugs, muscle relaxants and neuroleptic agents. Large-scaled placebo-controlled clinical trials are scarce. For patients refractory to medical therapy, Gasserian ganglion percutaneous techniques, gamma-knife surgery and microvascular decompression are the most promising invasive treatment options. Continuous scientific research works towards a better understanding of trigeminal neuralgia and has accomplished a greater insight into the underlying pathophysiological mechanisms.

Disorders of cranial nerves IX and X

The glossopharyngeal and vagus nerves mediate the complex interplay between the many functions of the upper aerodigestive tract. Defects may occur anywhere from the brainstem to the peripheral nerve and can result in significant impairment in speech, swallowing, and breathing. Multiple etiologies can produce symptoms. In this review, the authors broadly examine the normal functions, clinical examination, and various pathologies of cranial nerves IX and X.