Familial classic trigeminal neuralgia.

INTRODUCTION

The classic form of trigeminal neuralgia is usually sporadic (no familial clustering). However, around 2% of all cases of trigeminal neuralgia may be familial. Describing this entity may be useful for diagnosing this process and may also be key to determining the underlying causes of sporadic classical trigeminal neuralgia. We report on cases in a series of 5 families with at least 2 members with classic trigeminal neuralgia, amounting to a total of 11 cases.

MATERIAL AND METHODS

We recorded cases of familial classical trigeminal neuralgia between March 2014 and March 2015 by systematically interviewing all patients with a diagnosis of trigeminal neuralgia who visited the neurology department on an outpatient basis.

RESULTS

In our sample, most patients with familial classic trigeminal neuralgia were women. Mean age at onset was 62.9±13.93 years, decreasing in subsequent generations. V2 was the most frequently affected branch. Most of our patients responded well to medical treatment, and surgery was not effective in all cases.

CONCLUSIONS

These family clusters support the hypothesis that classic trigeminal neuralgia may have a genetic origin. Several causes have been suggested, including inherited anatomical changes affecting the base of the skull which would promote compression of the trigeminal nerve by vascular structures, familial AHT (resulting in tortuous vessels that would compress the trigeminal nerve), and mutations in the gene coding for calcium channels leading to hyperexcitability. Classic trigeminal neuralgia may be an autosomal dominant disorder displaying genetic anticipation.