Classical Trigeminal Neuralgia and Sodium Channel Mutations

Study Overview
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Brief Summary
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The most common cause of trigeminal neuralgia is considered to be a neurovascular contact. However, this etiological factor only seem to be present in half of the patient group. Thus the etiology of the other half is unknown. Gain-of function genetic mutations in voltage gated sodium channels have been hypothesized as playing a role in the etiology of trigeminal neuralgia but it has yet to be confirmed. In recent years gain-of-function mutations have been identified as a causative factor in other pain-diseases presenting with trigeminal neuralgia phenotypic similarities.

Detailed Description
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The aim of this study was to indentify VGSC gene mutations, specifically SCN9A, SCN10A and SCN11A genes, in a group of well characterized trigeminal neuralgia patients. Setting: The study will be conducted at The Danish Headache Center, Rigshospitalet - Glostrup, Denmark (inclusion of patients and written Informed Consent, patient interview, phenotyping/diagnosis, neurological examination, blood sample. Departments of Neurology and Clinical Genomics of the Maastricht University Medical Center, Maastricht, the Netherlands: Targeted NG Sanger Sequencing

Official Title
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Classical Trigeminal Neuralgia and Sodium Channel Mutations

Conditions
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Trigeminal Neuralgia

Intervention / Treatment
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* Other: Observational


Participation Criteria
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Eligibility Criteria
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3.1. Inclusion Criteria Subjects of both sexes with TN must meet the following inclusion criteria to be eligible for participation: Patients must be able to give Signed Informed Consent prior to study entry Patients fulfilling of the ICHD-3 beta diagnostic criteria for classical TN.1 Age 18 years or older. Age at debut < 42 years and/or confirmed first-line relative with TN. Respond to sodium channel blockers with a 50% reduction of pain intensity evaluated by both the patient and the examining physician using the visual analog scale (VAS). 3.2. Exclusion Criteria Subjects will be excluded if one of the following exclusion criteria is met: Psychiatric or mental illness of physical condition that might interfere with the ability of the patients to fill in the Informed Consent and questionnaires. History of herpes zoster in the distribution of the trigeminal nerve ipsilateral to pain, multiple sclerosis or a space-occupying lesion. History indicative of painful posttraumatic trigeminal neuropathy such as previous trauma, surgery or radiation to the trigeminal nerve ipsilateral to pain.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: Observational|No intervention is conducted as the study aim is to explore the link between pheno- and genetype of trigeminal neuralgia|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Exploratory study of association between phenotype and genotype of trigeminal neuralgia | To identify genetic mutations, via Sanger Next Generation Sequencing, in either NaV 1.7, NaV1.8 or NaV1.9 encoding genes and link the findings to the phenotype of trigeminal neurlagia patients with a high genetic load. | 1 day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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genetic mutations, voltage gated sodium channels, phenotype,