Treatment of postherpetic trigeminal neuralgia with the gamma knife

Object. Postherpetic neuralgia is a syndrome characterized by intractable p ain. Treatment of this pain has not yet been successful. Patients with post herpetic neuralgia will therefore benefit from any progress in the treatmen t strategy. The authors performed gamma knife radiosurgery (GKS) as a nonin vasive treatment for postherpetic trigeminal neuralgia (TN) and evaluated t he success rate for pain relief. Methods. Between 1995 and February 1999, six men and 10 women were treated for postherpetic TN; conservative treatment failed in all of them. The medi an follow up was 33 months (range 8-34 months). The radiation was focused o n the root of the trigeminal nerve in the vicinity of the brainstem (maxima l dose 70-80 Gy in one fraction, 4-mm collimator). The patients were divide d into five groups according to degree of pain relief after treatment. A successful result (excellent, very good, and good) was reached in seven ( 44%) patients and radiosurgery failed in nine (56%). Pain relief occurred a fter a median interval of 1 month (range 10 days-6 months). No radiation-re lated side effects have been observed in these patients. Conclusions. These results suggest that GKS for postherpetic TN is a relati vely successful and safe method that can be used in patients even if they a re in poor condition. In case this method fails, other treatment options in cluding other neurosurgical procedures are not excluded.