Radiofrequency Thermoablation of the Gasserian Ganglion Versus the Peripheral Branches of the Trigeminal Nerve for Treatment of Trigeminal Neuralgia: A Randomized, Control Trial

Abstract

Background: Trigeminal neuralgia is the most painful condition of facial pain leading to impairment of routine activities. Although radiofrequency thermoablation (RFT) of the Gasserian ganglion is widely used for the treatment of idiopathic trigeminal neuralgia in patients having ineffective pain relief with medical therapy, the incidence of complications like hypoesthesia, neuroparalytic keratitis, and masticatory muscles weakness is high. Recent case reports have shown the effectiveness of RFT of the peripheral branches of the trigeminal nerve for relief of refractory chronic facial pain conditions including trigeminal neuralgia.

Objectives: This study was conducted to compare the efficacy and safety of RFT of the peripheral branches of the trigeminal nerve with RFT of the Gasserian ganglion for the management of idiopathic trigeminal neuralgia.

Study design: Prospective, randomized, observer-blinded, clinical trial.

Setting: Tertiary care hospital and medical education and research institute.

Methods: A total of 40 adult patients of idiopathic trigeminal neuralgia were randomly allocated into 2 groups. The control group received RFT of the Gasserian ganglion while the study group received RFT of the peripheral branches of trigeminal nerve. The procedures were performed in the operation room under all aseptic precautions with fluoroscopic guidance. Post-procedure, the patients were assessed for loss of sensation along the nerve distribution and the adequacy of pain relief on the Numerical Rating Scale (NRS). The patients were followed up for 3 month to assess the quality of pain relief by the NRS and the Barrow Neurological Institute (BNI) pain intensity scale. Improvement in pain was considered excellent if patients had complete pain relief without any medication, good if there was significant reduction in pain (> 50%) with or without medication, and poor if there was less than 50% reduction in pain with medications. Patients were also assessed for numbness and any other side effects. Patients' satisfaction with the procedure was recorded.

Results: Nineteen patients in the control group and 18 in study group had effective pain relief of up to 3 months. Their pain scores were comparable at all time intervals, though the number of patients receiving supplementary medications was more in study group at 2 months (P = 0.015). The patients showed overall satisfaction score of 8.5 (8-9) and 8 (7-9) in control and study groups respectively. The average procedure duration was 30 (30-38) minutes in the control group and 28 (25-40) minutes in the study group. Most of the patients in both groups had mild numbness after the procedure. One patient in the control group had lower eyelid swelling and another had mild weakness of the masseter muscle, which resolved few days later. No major complication was reported in the study group except for 1 patient who reported local ecchymosis.

Limitations: The main limitation of the study is that the patients and the investigator performing the procedure were not blinded, though the person who assessed the patient during follow-up was blinded to the group assignment. Another limitation is that we could not follow up with the patients after 3 months due to time constraints.

Conclusion: We found that radiofrequency thermoablation of the peripheral branches of the trigeminal nerve is an effective and safe procedure for the management of idiopathic trigeminal neuralgia.

Key words: Idiopathic trigeminal neuralgia, radiofrequency thermoablation, Gasserian ganglion, peripheral nerve branches, pain, trigeminal nerve.