Familial occurrence of classical and idiopathic trigeminal neuralgia

Per Kristian Eide

doi:10.1016/j.jns.2021.120101

Abstract

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.

Highlights

Trigeminal neuralgia (TN) or “tic doulourex” is a chronic neuro pathic pain disorder characterized by spontaneous and elicited parox ysms of electric shock-like or stabbing pain, in the distribution of one or more branches of the trigeminal nerve [1]
The questionnaire was sent to 477 TN patients, hundred and ninety-two patients did not respond, 17 individuals were excluded according to the exclusion criteria, leaving a
Like wise, a recent systematic review identified in the literature from 1938 to 2019, 27 families with 98 TN individuals and a reported prevalence of familial TN about 1–2% [5]

Summary

Introduction

Trigeminal neuralgia (TN) or “tic doulourex” is a chronic neuro pathic pain disorder characterized by spontaneous and elicited parox ysms of electric shock-like or stabbing pain, in the distribution of one or more branches of the trigeminal nerve [1]. Vascular compression of the trigeminal nerve at the root entry zone is the most well-accepted cause of TN [2], and denoted classical TN. Microvascular decompression (MVD) is first line surgery for classical TN [1]. Secondary TN may result from lesions such as tumors or vascular malformations in the posterior fossa, or be caused by multiple sclerosis. When no cause is identified, TN is denoted idiopathic. Even though etiological factors have been identified, the underlying pathophysiology remains largely un known. Understanding these mechanisms are required for better treat ment strategies. A significant number of patients experience pain recurrence despite state of the art medical and surgical treatment, which extensively affect quality of life [3]

Methods

Discussion

Conclusion