Clinical Outcomes After Gamma Knife Surgery For Idiopathic Trigeminal Neuralgia: Review Of57Consecutive Cases Follow Up More Than2Years

objective: Stereotactic radiosurgery is an increasingly used, andthe least invasive, surgical option for patients with trigeminal neuralgia (TN). Inthis study, the authors performed a retrospective evaluation of the safety andefficacy of this method for idiopathic TN. Methods: a retrospective analysis inOctober2005-October2009in-patient treatment in our hospital’s clinicalpathology imaging in suspected primary trigeminal neuralgia, and werefollowed up.57patients underwent gamma-knife surgery were follow-up inour study.24male, and33female. The average old is68.19years old (rang42-91years old). Duration of symptoms (years) is7.54year (arrange2to22years). All patients had typical features of TN. Symptomatic side is conclude,right38and the left is37patients. The pain distribution of series is V2patients（15.8%）;V3:11patients（19.3%）;V1–V2:1patient（1.8%）; V2–V3:20patients（35.1%）；V1–V2–V3:14patients（24.6%）.all patients had drugsbefore.8patient（s14.0%）had percutaneous radiofrequency thermo coagulationbefore. We found vessel attach to nerve Ⅴ in33patients（57.9%）. We recorded5species of materials of the anatomy include of the length of V5incerebellar-pon-cistern, the expose of the level numbers of the nerve, thediameter of the nerve of expose, the distance of the interval between theincisures to the REZ, and the angle to V5and the pons.57patients had one time GKS giving average83.3Gy(arrange from70-90Gy), one isodose,20peri-curve cover the target, and the reacceptance dose of the pons under18Gy.a kind of factor include of the anatomy factor of the target is concludeand analysis.1. By single factor log-rank test of age, gender, MRI features,Dose of radio surgery, etc. Patients were followed up for more than2year. Toonset time as the initial event, with pain-free as an event destination.Application of Kaplan-Meier method survival curves plotted (log-rank test);2through the exact chi-square test, T test analysis of the factors affecting the painrelief beyond the BNI score Ⅲ, invalid and the recurrence.) Results:57patients had follow up average42.57months (arrange from24to72months).57patients are survived and4patients were dead. The time of pain relief isaverage6.15months (arrange from0.5to17months). According to BNI score,28patients was Ⅰ (49.1%),17patients was Ⅲ (29.8%),8patients was Ⅲ(14.0%),1patient was Ⅳ (1.8%),3patients were V (5.3%). The total painrelief was92.9%(the scores beyond Ⅲ).3patients were recurrence,5.3%. Thenew face numbness were found in14patients.，according to BNI numbnessscores,12patients were1score and2patients were2score. One patient hadfacial hyperplasia. Through the exact chi-square test, less-than80Gy group andbeyond80Gy group is significant difference (P=0.042＜0.05), rate of the painrelief is79.2%in the beyond80Gy are more than25%in the less than80Gy.1university survival analysis log-rank test showed that prognostic of TN patientfactor was length of the REZ to, the gap between, and the sex. Conclusion:1，using survival analysis methods,found and identified the impact of the affect the factors: The length of the exposed nerve of V, the gap between theTrigeminal semilunar ganglion notch and Pons, sex.2using the exactchi-square test found the affect curative effect is the dose. No factor can affectthe recurrence and invalid.