Study of the outcome of patients undergoing pulsed radiofrequency for the treatment of Trigeminal Neuralgia: An observational study.

Background: Trigeminal neuralgia is sudden unilateral severe, stabbing, recurrent episodes of pain in the distribution of one or more branches of the trigeminal nerve. Pulsed radiofrequency stimulation (PRF) has been recently introduced to alleviate neural, joint pain, and muscle pain. We tried to use PRF for pain relief in trigeminal neuralgia. The primary objective of our study was to observe the effectiveness and safety of pulsed radiofrequency in the patients of trigeminal neuralgia who are refractory to medical management. The secondary objective was to study the effect of pulsed radiofrequency on the duration of pain relief in these patients. Methodolgy: In this observational study, we enrolled all fresh patients with trigeminal neuralgia attending our pain clinic for the first time and those who had not responded to conservative medical treatment or interventional nerve blocks. All the patients were diagnosed on the basis of signs, symptoms and MRI (CISS sequence). Anatomical landmarks of ophthalamic nerve, maxillary nerve, mandibular nerve were identified and nerve stimulation was done by placing the probe in the affected nerve division. Each point was stimulated with the radiofrequency probe kept for 10 minutes, giving a current of 10 to 30 milli-amperes with a set frequency of 2 Hertz. A total of 10 settings were given on alternate days. Assessment of pain relief, improvement, or deterioration was done using Barrow Neurological Institute Pain Intensity Score and Brief Pain Inventory facial scale scoring. Results: There was a significant reduction in pain scores observed on Barrow neurological institute (BNI) and Brief Pain Inventory-(BPI) pain intensity score (p value of <0.05) before and after pulsed radiofrequency (PRF) application. The duration of pain relief after the application of PRF was up to 180 days in 15 patients, 181-300 days in 8 patients and 300 to 600 days in 7 patients. Only 2 patients had a prolonged pain relief lasting for 601-720 days. One patient had developed exposure keratitis after 4 sittings of pulsed radiofrequency application at the supraorbital foramen. Conclusion: PRF offers short term relief in a majority of patients for a period of 18 months to 24 months. However, it was found that the long term effects of PRF may not be seen in patients with TN. PRF may be used as a short term measure for alleviating severe pain of TN till neurolytic blocks or a definitive surgery is carried out. [ABSTRACT FROM AUTHOR]