両側三叉神経痛の臨床像

Clinical Features of Bilateral Trigeminal Neuralgia

Ⅰ．はじめに

　三叉神経痛は通常一側の三叉神経の1枝から3枝の領域に一致して，刺すような短い激痛が突然に，何らかの刺激を誘因として繰り返し起こる³⁾．症状のみから診断可能であるが，両側に痛みがある場合には診断に苦慮する．三叉神経痛の頻度は欧米では10万人につき4〜5人，両側三叉神経痛は三叉神経痛全体の数%と報告されているが^3,10,12)，本邦では渉猟し得た限り，まとまった報告は皆無である．そのためか両側三叉神経痛はあまり知られておらず，的確な診断が行われていない．当科では，5例の両側三叉神経痛の手術例を経験したので，片側例と比較・検討を行い，若干の文献的考察，画像所見を加えて報告する．

　Among 238 patients with bilateral trigeminal neuralgia（TN）who visited our hospital between April 2007 and June 2014, 5（2%）were surgically treated by microvascular decompression（MVD). The initial symptom was on the right side in four and on both sides in one patient. Intervals between the initial and second onset on the other side（left）were two months, and four, six, and eight years. None of the patients showed involvement of the first branch of the trigeminal nerve. The patients with bilateral TN were younger than the 154 patients with unilateral TN who were treated surgically by MVD in this period（45 vs. 65 years), and the bilateral TN patients predominantly were women（4/5 vs. 99/154). In the surgical field, the trigeminal nerve and root entry zone were compressed more by veins in the bi lateral TN patients than in the unilateral TN（4/5 vs. 60/154, respectively）patients. We could not identify any differences in MRI CISS before versus after the onset of left trigeminal neuralgia, suggesting that compression is not the sole cause of the symptom.