Stereotactic radiosurgery for post-herpetic trigeminal neuralgia: results of a case-control study

Radiosurgery is a minimally invasive therapy for intractable classical trigeminal neuralgia (TN) with favorable outcomes. However, a little of studies have reported about the effects of stereotactic radiosurgery (SRS) on post-herpetic neuralgia (PHN). Herein, we report our institutional experience and aim to compare the outcomes of classical TN versus PHN after SRS. A case-control study of four patients with PHN and 16 control patients with TN who underwent SRS was performed to evaluate the probability of pain relief, pain recurrence, complications, and medication-free status. Three of four patients with PHN exhibited significant pain relief and discontinued drug use after radiosurgery. The latent period between SRS and perceived pain improvement ranged from 0.3 to 1 month. Two patients in PHN groups sustained minor recurrent pain along the previously affected location at 2 and 2.5 years after treatment. Compared with patients with TN, those with PHN were less likely to respond favorably to SRS, exhibiting a lower initial pain relief rate (75% vs. 94%), a higher pain recurrence rate (50% vs. 19%), and a higher incidence of post-treatment numbness (75% vs. 38%). However, due to the relatively small sample size in each group, the study was underpowered to detect statistically significant differences. Our preliminary results demonstrated that three of four patients achieved pain palliation following radiosurgery for PHN, with a median latency period of one month. Radiosurgery may be a feasible and safe therapeutic option for these clinically challenging cases of PHN.