Comparison of pulsed radiofrequency with conventional radiofrequency in the treatment of idiopathic trigeminal neuralgia. Does increased nerve length within the treatment volume improve trigeminal neuralgia radiosurgery? A prospective double-blind, randomized study. Neuronavigator-guided percutaneous radiofrequency thermocoagulation in the treatment of intractable trigeminal neuralgia. The effects of streptomycin/lidocaine block on trigeminal neuralgia: a double blind crossover placebo controlled study. Peripheral streptomycin/lidocaine injections versus lidocaine alone in the treatment of idiopathic trigeminal neuralgia. A double blind controlled trial. The treatment of first division idiopathic trigeminal neuralgia with radiofrequency thermocoagulation of the peripheral branches compared to conventional radiofrequency.
The aim of this prospective, randomized, double-blinded study was to evaluate the effect of pulsed radiofrequency (PRF) in comparison with conventional radiofrequency (CRF) in the treatment of idiopathic trigeminal neuralgia. A total of 40 patients with idiopathic trigeminal neuralgia were included. The 20 patients in each group were randomly assigned to one of the two treatment groups. Each patient in the Group 1 was treated with CRF, whereas each patient in the Group 2 was treated by PRF. Evaluation parameters were: pain intensity using a Visual Analogue Scale (VAS), patient satisfaction using a Patient Satisfaction Scale (PSS), additional pharmacological treatment, side effects, and complications related to the technique. The VAS scores decreased significantly (p<0.001) and PSS improved significantly after the procedure in Group 1. The VAS score decreased in only 2 of 20 patients from the PRF group (Group 2) and pain recurrence occurred 3 months after the procedure. At the end of 3 months, we decided to perform CRF in Group 2, because all patients in this group still had intractable pain. After the CRF treatment, the median VAS score decreased (p<0.001) and PSS improved (p<0.001) significantly. In conclusion, the results of our study demonstrate that unlike CRF, PRF is not an effective method of pain treatment for idiopathic trigeminal neuralgia. To test the hypothesis that increasing the nerve length within the treatment volume for trigeminal neuralgia radiosurgery would improve pain relief.
                Eighty-seven patients with typical trigeminal neuralgia were randomized to undergo retrogasserian gamma knife radiosurgery (75 Gy maximal dose with 4-mm diameter collimators) using either one (n = 44) or two (n = 43) isocenters. The median follow-up was 26 months (range 1-36).
                Pain relief was complete in 57 patients (45 without medication and 12 with low-dose medication), partial in 15, and minimal in another 15 patients. The actuarial rate of obtaining complete pain relief (with or without medication) was 67.7% +/- 5.1%. The pain relief was identical for one- and two-isocenter radiosurgery. Pain relapsed in 30 of 72 responding patients. Facial numbness and mild and severe paresthesias developed in 8, 5, and 1 two-isocenter patients vs. 3, 4, and 0 one-isocenter patients, respectively (p = 0.23). Improved pain relief correlated with younger age (p = 0.025) and fewer prior procedures (p = 0.039) and complications (numbness or paresthesias) correlated with the nerve length irradiated (p = 0.018).
                Increasing the treatment volume to include a longer nerve length for trigeminal neuralgia radiosurgery does not significantly improve pain relief but may increase complications. Percutaneous radiofrequency thermocoagulation of the trigeminal ganglion (PRTTG) is regarded as the first choice for most patients with trigeminal neuralgia (TN) because of its safety and feasibility. However, neuronavigator-guided PRTTG has been seldom reported. The purpose of this study was to assess the safety and efficacy of neuronavigator-guided PRTTG for the treatment of intractable TN.
                Between January 2000 and December 2004, 54 patients with intractable TN were enrolled into this study and were randomly divided into two groups. The patients in navigation group (n = 26) underwent PRTTG with frameless neuronavigation, and those in control group (n = 28) received PRTTG without neuronavigation. Three months after the operation, the efficacy, side effects, and complications of the surgery were recorded. The patients in the control group were followed up for 10 to 54 months (mean, 34 +/- 5), and those in the navigation group were followed up for 13 to 58 months (mean, 36 +/- 7). Kaplan-Meier analyses of the pain-free survival curves were used for the censored survival data, and the log-rank test was used to compare survival curves of the two groups.
                The immediate complete pain-relief rate of the navigation group was 100%, whereas it was 95% in the control. The proportion of sustained pain-relief rates at 12, 24 and 36 months after the procedure were 85%, 77%, and 62% in the navigation group, and 54%, 40%, and 35% in the control. Recurrences in the control group were more common than that in the navigation group. Annual recurrence rate in the first and second years were 15% and 23% in the navigation group, and 46%, 60% in the control group. No side-effect and complication was noted in the navigation group except minimal facial hypesthesia.
                Neuronavigator-guided PRTTG is a safe and promising method for treatment of intractable TN with better short- and long-term outcomes and lower complication rate than PRTTG without neuronavigation. This study investigated the long term effect of a peripheral sensory block using streptomycin sulphate on trigeminal neuralgia. A total of twenty subjects, thirteen with idiopathic trigeminal neuralgia (ITN) and seven with traumatic trigeminal neuralgia (TTN) were studied. A double-blind placebo controlled randomized design was used. After the clinical assessment subjects were randomly assigned to receive either 1 g of streptomycin with 3 ml 2% lidocaine, or 3 ml lidocaine alone. The injections were performed adjacent to the branches that served the painful site. These were intraoral injections, more specifically infraorbital and inferior alveolar blocks. Patients received five blocks of either streptomycin/lidocaine or lidocaine alone for a period of five consecutive weeks. On the sixth week they were crossed over. Measures of pain intensity and pain frequency were used to assess treatment outcome. Patients also recorded their side-effects. Repeated measures analysis of variance was used to compare the treatment outcomes between the active and placebo groups. There was no statistically significant differences in the treatment outcomes regarding frequency and intensity of pain attacks. The sensory function of the treated nerves was also not affected. Side effects including facial swelling and pain were a common finding in the patients receiving streptomycin. This study demonstrated no beneficial effects of streptomycin blockade for idiopathic and traumatic trigeminal neuralgia. Seventeen patients with long-lasting idiopathic trigeminal neuralgia (ITN) were treated with either five, weekly peripheral streptomycin/lidocaine (S/L) or lidocaine alone injections, in a double blind controlled study. Eight patients responded initially to the treatment in the S/L group and three patients in the lidocaine group. Pain recurred in four patients from the S/L group within two weeks and six months following the last injection. One patient from the lidocaine group remained pain-free for eight months. At the final assessment, three patients from the S/L group and two patients from the lidocaine group remained pain-free up to 30 months. Neither treatment affected sensory functions of the injected nerves. It is concluded that S/L injections are initially effective in the treatment of ITN. In the long term, however, their effects are similar to the effects of lidocaine alone. The aim of this study was to prospectively evaluate and compare the effects of radiofrequency thermocoagulation of the first division branches of the trigeminal nerve (trigeminal peripheral division radiofrequency thermocoagulation, PRT) versus conventional radiofrequency (CRF) in the treatment of first division idiopathic trigeminal neuralgia (ITN). Fifty patients with first division ITN were randomly divided into two groups. The 20 patients in group 1 were treated with CRF, while the remaining 30 patients in group 2 were treated using PRT. The immediate therapeutic effects, side effects and recurrence rate of idiopathic trigeminal neuralgia were evaluated. The immediate efficacy rates were 95% and 93% in groups 1 and 2, respectively. The recurrence rates of ITN at the 3-year follow-up were 25% and 27% for group 1 and group 2, respectively, and 35% and 40%, respectively, 5 years after treatment. There were no significant differences between groups 1 and 2 at any time. Our study demonstrates that PRT is an effective way to treat first division ITN.
There is very low quality evidence for the efficacy of most neurosurgical procedures for trigeminal neuralgia because of the poor quality of the trials. All procedures produced variable pain relief, but many resulted in sensory side effects. There were no studies of microvascular decompression which observational data suggests gives the longest pain relief. There is little evidence to help comparative decision making about the best surgical procedure. Well designed studies are urgently needed.