Familial classic trigeminal neuralgia

Trigeminal and Glossopharyngeal Neuralgia

Trigeminal neuralgia and glossopharyngeal neuralgia are craniofacial pain syndromes characterized by recurrent brief shock-like pains in the distributions of their respective cranial nerves. In this article, the authors aim to summarize each condition's characteristics, pathophysiology, and current pharmacotherapeutic and surgical interventions available for managing and treating these conditions.

Classical trigeminal neuralgia is associated with gephyrin and sodium voltage-gated channel alpha subunit 8

Trigeminal neuralgia is highly debilitating, and its etiology is still undefined. The goal of this work was to define associations between well-characterized trigeminal neuralgia cases and common genetic variants in the population. two hundred and fifty-seven individuals diagnosed with classical trigeminal neuralgia were compared to 865 individuals without classical trigeminal neuralgia and with an assessment for lower or higher pain threshold based on the amount of anesthetic required for routine dental treatment. Genotypes of 24 variants marking genes in the VGSC (voltage-gated sodium channels) or GABA (gamma-aminobutyric acid) pathways were obtained using TaqMan chemistry end end-point analysis. Chi-square was used for all comparisons with an alpha of 0.002. An association between classical trigeminal neuralgia and individuals requiring less or more anesthetic for routine dental treatments showed associations with SCN8A rs1601012 and GPHN rs723432 (p = 0.0009 and p = 0.0002, respectively). In conclusion, classical trigeminal neuralgia is associated with SCN8A and GPHN and markers rs1601012 rs723432 may be useful to determine individual risks for the condition.

Familial occurrence of classical and idiopathic trigeminal neuralgia

Trigeminal neuralgia (TN) is a severe facial pain disease with unknown pathogenesis. It has been thought that the familial form of TN is rare with a prevalence of about 1-2% among affected individuals, but emerging evidence suggests a role of genetic factors. This study examined the occurrence of familial TN among patients with classical or idiopathic TN. Patients with TN recruited from a hospital registry received an informed consent form with a questionnaire, and individuals reporting other family members with TN underwent a structured phone-interview. For affected family members, type of TN, available clinical, imaging, management results and available hospital patient records were studied. Pedigrees for all affected families were established. This study included 268 patients with either classical or idiopathic TN. The familial form of TN was present in 41/268 (15.3%) patients, that is, 37/244 (15.2%) patients with classical TN and in 4/24 (16.7%) with idiopathic TN. Total 38 families were identified, with two affected members in 32/38 families (84.2%), three affected family members in 5/38 (13.2%) and four family members in 1/38 (2.6%) families. Comparing the 41 familial TN cases with the 227 sporadic TN patients showed significantly earlier onset of TN and a significantly higher occurrence of right-sided pain in familial cases, while there was no difference in gender distribution, occurrence of arterial hypertension or trigeminal branch involved. Among patients with classical or idiopathic TN, the occurrence of the familial form of the disease is more frequent than traditionally assumed.

The changing face of trigeminal neuralgia-A narrative review

OBJECTIVE

This narrative review aims to update the reader on the new classification of trigeminal neuralgia (TN), clinical signs, pathophysiologic evidence, and their implications on management. This review is based on the authors' collective experience and knowledge of the literature in addition to a literature search.

BACKGROUND

In recent years, the phenotype of TN has been intensively studied leading to discrete groups of patients. These include patients with TN with additional continuous pain, and patients with and without neurovascular compression of the trigeminal dorsal root entry zone. A number of associated clinical signs such as tearing and sensory changes need further research.

METHODS

The literature on TN was searched in PubMed with the aims of providing evidence for the recently published third edition of the International Classification of Headache Disorders (ICHD) and update the clinical phenotype and management of the TN subcategories.

RESULTS

The ICHD's new classification for TN is based on reliable clinical data, imaging, and neurophysiologic studies. The TN classification reflects current knowledge and has improved the possibility for clinicians to choose adequate management options. However, there is a lack of effective, safe drugs for the management of TN and sparse, robust data on neurosurgical options.

CONCLUSION

Research into all aspects of TN-diagnosis, pharmacotherapy, surgery, long-term management prognosis, and natural history-is needed. Research should adhere to the ICHD's schema for TN. Improved drugs are needed along with rigorous research into surgical options and their efficacy for different subtypes of TN.

Assessment of Growth Factors, Cytokines, and Cellular Markers in Saliva of Patients with Trigeminal Neuralgia

We proposed to perform a comparative analysis of growth factors, cytokines, and chemokine receptors on the salivary cells in the saliva obtained from trigeminal neuralgia (TN) and normal subjects. Saliva was collected from TN and healthy subjects. Salivary cells were isolated by centrifugation. The expression of the cell surface marker was analyzed by flow cytometry. A cytometric bead array was done to measure the levels of cytokines and growth factors on the flow cytometer. Saliva from TN subjects showed lower growth factor levels of Angiopoietin-2, bFGF, HGF, SCF, TGF-α, and VEGF and higher cytokine levels of IL-1β, TNF-α, CCL2, IL-17A, IL-6, and CXCL8, as well as higher expression levels of chemokine receptors CCR1 (CD191), CR3 (CD11b), CCR2 (CD192), CXCR5 (CD185), and CCR5 (CD196) in the cells from TN saliva. A certain set of cytokines and growth factors in the saliva, as well as chemokine receptors on salivary cells, could be a useful tool in the diagnostics and prognostics of trigeminal neuralgia. Trigeminal neuralgia is one of the significant pathological conditions in the class of chronic diseases around the world. Many targeted approaches are being tried by various research groups to utilize the information of the inflammatory microenvironment to resolve the pathology of chronic TN.

Trigeminal neuralgia and genetics: A systematic review

Trigeminal neuralgia (TN) is a severe facial pain disease of unknown cause and unclear genetic background. To examine the existing knowledge about genetics in TN, we performed a systematic study asking about the prevalence of familial trigeminal neuralgia, and which genes that have been identified in human TN studies and in animal models of trigeminal pain. MedLine, Embase, Cochrane Library and Web of Science were searched from inception to January 2021. 71 studies were included in the systematic review. Currently, few studies provide information about the prevalence of familial TN; the available evidence indicates that about 1–2% of TN cases have the familial form. The available human studies propose the following genes to be possible contributors to development of TN: CACNA1A, CACNA1H, CACNA1F, KCNK1, TRAK1, SCN9A, SCN8A, SCN3A, SCN10A, SCN5A, NTRK1, GABRG1, MPZ gene, MAOA gene and SLC6A4. Their role in familial TN still needs to be addressed. The experimental animal studies suggest an emerging role of genetics in trigeminal pain, though the animal models may be more relevant for trigeminal neuropathic pain than TN per se. In summary, this systematic review suggests a more important role of genetic factors in TN pathogenesis than previously assumed.

Chronic Facial Pain: Trigeminal Neuralgia, Persistent Idiopathic Facial Pain, and Myofascial Pain Syndrome-An Evidence-Based Narrative Review and Etiological Hypothesis

Trigeminal neuralgia (TN), the most common form of severe facial pain, may be confused with an ill-defined persistent idiopathic facial pain (PIFP). Facial pain is reviewed and a detailed discussion of TN and PIFP is presented. A possible cause for PIFP is proposed. (1) Methods: Databases were searched for articles related to facial pain, TN, and PIFP. Relevant articles were selected, and all systematic reviews and meta-analyses were included. (2) Discussion: The lifetime prevalence for TN is approximately 0.3% and for PIFP approximately 0.03%. TN is 15-20 times more common in persons with multiple sclerosis. Most cases of TN are caused by neurovascular compression, but a significant number are secondary to inflammation, tumor or trauma. The cause of PIFP remains unknown. Well-established TN treatment protocols include pharmacotherapy, neurotoxin denervation, peripheral nerve ablation, focused radiation, and microvascular decompression, with high rates of relief and varying degrees of adverse outcomes. No such protocols exist for PIFP. (3) Conclusion: PIFP may be confused with TN, but treatment possibilities differ greatly. Head and neck muscle myofascial pain syndrome is suggested as a possible cause of PIFP, a consideration that could open new approaches to treatment.

Exome Sequencing Implicates Impaired GABA Signaling and Neuronal Ion Transport in Trigeminal Neuralgia

Trigeminal neuralgia (TN) is a common, debilitating neuropathic face pain syndrome often resistant to therapy. The familial clustering of TN cases suggests that genetic factors play a role in disease pathogenesis. However, no unbiased, large-scale genomic study of TN has been performed to date. Analysis of 290 whole exome-sequenced TN probands, including 20 multiplex kindreds and 70 parent-offspring trios, revealed enrichment of rare, damaging variants in GABA receptor-binding genes in cases. Mice engineered with a TN-associated de novo mutation (p.Cys188Trp) in the GABA_A receptor Cl⁻ channel γ-1 subunit (GABRG1) exhibited trigeminal mechanical allodynia and face pain behavior. Other TN probands harbored rare damaging variants in Na⁺ and Ca⁺ channels, including a significant variant burden in the α-1H subunit of the voltage-gated Ca²⁺ channel Ca_v3.2 (CACNA1H). These results provide exome-level insight into TN and implicate genetically encoded impairment of GABA signaling and neuronal ion transport in TN pathogenesis.

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Genomic analysis of trigeminal neuralgia (TN) using exome sequencing

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Rare mutations in GABA signaling and ion transport genes are enriched in TN cases

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Generation of a genetic TN mouse model engineered with a patient-specific mutation

Clinical characteristics and associated factors of trigeminal neuralgia: experience from Addis Ababa, Ethiopia

Background

Trigeminal neuralgia (TN) is considered one of the most painful illnesses known to medical practice. Little is known about TN in Ethiopia. Our study aimed to assess clinical characteristics, treatment, and associated factors of TN.

Method

A cross-sectional study was conducted on a total of 61 patients with confirmed Trigeminal neuralgia visiting outpatient neurology clinics of two government teaching Hospitals and two private health facilities in Addis Ababa, Ethiopia between June 2019 and March 2020.

Results

Our participants’ age range between 21 and 78 years with mean ± SD age of 50.7 ± 14.2 years. Males accounted for 50.8%. Twenty-five (41%) reported a prior history of one or more tooth extraction on the painful side. In the majority (68.9%) of the patient’s right side of the face was affected. The mandibular nerve was the commonly involved branch (47.5%). Fifty-five (90.2%) of patients fulfilled criteria for classical TN and 9.8% had symptomatic TN. The majority of the participants reported mixed types of pain such as burning, lancinating, and electric shock-like. Well defined trigger zone was identified in one-third (36%) of cases. Carbamazepine was the most commonly prescribed drug with a median dose of 600 mg (IQR: 400 – 1000 mg). Two-third of the patients reported prominent satisfaction. The mean (± SD) dose of carbamazepine used to control the pain was significantly higher among those with dental extraction history as compared to those with no history of dental extraction (736 ± 478.6 mg Vs 661.1 ± 360.4 mg, respectively, T = − 2.06, p = 0.04 95% CI:-213.41 to − 2.98). A statistically significant number of patients who had single branch involvement reported prominent satisfaction with their treatment as compared to those who had more than one branch involvement. (95% CI: 1.3–3.8: p = 0.006).

Conclusion

The majority of our patients had Classical TN in the mandibular nerve distribution on the right side of the face and well satisfied with carbamazepine only treatment. Furthermore, we observed a higher proportion of dental extraction among our patients, hinting at the scale of miss and delayed-diagnoses. Thus, we recommend conducting a well-designed prospective study to support our findings.

Surgical Management of Familial Trigeminal Neuralgia With Different Inheritance Patterns: A Case Report

Introduction

Trigeminal neuralgia is a disorder characterized by unilateral electric shock-like pain, distributed in one or more trigeminal nerve branches and triggered by usually innocuous stimuli. Among the few case reports and literature reviews on familial trigeminal neuralgia (FTN), the results of several suggest the involvement of genes associated with biochemical alterations or atherosclerotic vascular malformations.

Background

We present four cases of FTN within two families (family A: two brothers; family B: two sisters). All patients were submitted to surgical treatment by the same surgeon.

Discussion

Cases 1 and 2 (family A) exhibited FTN with an uncommon autosomal recessive pattern and clinical features consistent with previous literature reviews and case reports. However, in cases 3 and 4 (family B), we found FTN with a dominant autosomal pattern and an unusual physiopathology characterized by arachnoid adhesions.

Conclusion

We conclude, in this case report, that there are several inheritance patterns as well as physiopathology that may be involved in FTN, and that both patterns described in our reported cases were successfully managed with surgery.