伽玛刀治疗原发性三叉神经痛的疗效

Curative Effect of Primary Trigeminal Neuralgia Gamma Knife

目的探讨原发性三叉神经痛的伽玛刀治疗效果。方法2004年1月～2008年11月,对34例经药物等保守治疗无效的原发性三叉神经痛采用伽玛刀治疗。治疗靶点为三叉神经根部,定位方法选择行三维时间飞跃法磁共振血管成像(3DMRA-TOF)三叉神经区扫描,使用4mm准直器、双靶点治疗,靶点中心剂量75～85Gy。通过复诊或电话随访了解疼痛的缓解程度、药物用量变化,观察伽玛刀疗效。结果随访时间6～53个月,平均37个月,疗效Ⅰ级(疼痛缓解100%)19例(56%),Ⅱ级(疼痛缓解>80%,无需药物控制)8例(24%),Ⅲ级(疼痛缓解50%～80%,少量用药控制)4例(12%),Ⅳ级(疼痛缓解<50%)3例(9%)。总有效率为91%(31/34)。术后至疼痛缓解时间6h～9个月,平均32d。8例(24%)治疗后3～27周内疼痛复发,其中5例于伽玛刀治疗18～24个月再次接受伽玛刀治疗,4例疼痛完全缓解(3例合并面部感觉麻木、蚁走感等感觉异常),1例症状仍无明显缓解。MRI定位患侧三叉神经根显示清楚的25例中,23例于伽玛刀治疗后当天～1年之内治疗效果达Ⅰ级或Ⅱ级,2例为Ⅲ级,而MRI定位患侧三叉神经根显示欠佳9例中,4例为Ⅱ级,2例为Ⅲ级,3例为Ⅳ级,2组差异有显著性(Z=-3.127,P=0.002)。结论伽玛刀治疗原发性三叉神经痛安全有效,复发后可接受第二次伽玛刀治疗。术前MRI定位能清晰显示三叉神经根部靶区解剖结构者疗效更好。

Objective To study the effect of Gamma knife in treating primary trigeminal neuralgia. Methods Totally 34 patients complaining trigeminal neuralgia with refractory medical management were treated with Gamma knife in our hospital from January 2004 to November 2008. The surgical targets were chosen at the root of trigeminal nerve and localized by using 3D MRA-TOF trigeminal or trifacial nerve area scanning with 4-mm collimator, two isocenters,and central doses at 75-85 Gy.Treatment effectiveness was evaluated through further patient consultation or telephone visits regarding to pain control and medication usage during follow-up visits. Results All the patients had been followed up for 6 to 53 months with a median of 37 months. During the period, complete pain relief （grade Ⅰ） was confirmed in 19 cases （56%） , pain relieved by 80% without need for medication （grade Ⅱ） was in 8 cases （24%） , pain relieved by 50%-80% with slight need for medication （grade Ⅲ） was in 4 cases （12% ）, and pain relief 50% （grade Ⅳ） was in 3 cases （9%）. The total effective rate was 91% （31/34）. After the operation, the pain was relieved in 6 hours to 9 months （mean, 32 days）. Eight patients （24%） had recurrence in 3 to 27 weeks, five of them received a second operation by Gamma knife in 18 to 24 months, after which four of the patients had complete pain relief （three of them complained facial numbness）, while the other one were not improved. In our patients, MRI showed the root of trigeminal nerve clearly in 25 cases, of which 23 patients achieved grade Ⅰ or Ⅱ in 1 day to 1 year after the treatment with Gamma knife, and the other 2 achieved grade Ⅲ. Whereas, in nine patients in whom MRI didn’t show the root of trigeminal nerve clearly, four patients achieved grade Ⅱ, 2 grade Ⅲ, and 3 grade Ⅳ. The surgical outcomes were significantly different between the two groups （Z=-3.127,P=0.002）. Conclusions Gamma knife is safe and effective for primary trigeminal neuralgia. Relapse after the first treatment can be cured by a second gamma knife treatment. The patients who had the roots of the trigeminal nerve being clearly showed by preoperative MRI have better therapeutic outcomes.