Since 1995 to June 1998 ninety five patients suffering from trigeminal neuralgia were treated by gamma knife irradiation at the Department of Stereotactic and Radiation Neurosurgery in the Hospital Na Homolce. Herein we report 49 patients (F/M = 26/23) with the minimal follow up 24 months from radiosurgery (interval 24 - 32 months, median 26 months). The radiation was focused on the root of the trigeminal nerve in the vicinity of the brainstem (maximal dose 70 - 80 Gy in one fraction, 4 mm collimator). Thirty one patients suffered from the essential neuralgia (EN), in 7 patients multiple sclerosis was accompanied by trigeminal neuralgia (MS), three patients were classified as atypical neuralgia (AN) and eight patients suffered from postherpetic pain in the distribution of the trigeminal nerve (PN). The patients were selected into five groups according to the pain relief after treatment. The successful result (excellent, very good and good) was reached in EN in 80.6%, MS 71.4%, AN 66.6% (but small number of subjects - only 3) and PN in 37.5%. The pain relief manifested in the interval between 1 day and 8 months (median 2 months). A slight tactile hypesthesia that appeared in 6% of the patients, was a clinical manifestation of an unwanted effect of the irradiation.

        Key words: gamma knife, radiosurgery, trigeminal neuralgia, postherpetic neuralgia