Clinical Outcomes and Complications following Internal Neurolysis for the Treatment of Trigeminal Neuralgia: An Institutional Case Series

Introduction: Treatment for trigeminal neuralgia (TN) has evolved over the years. Although medication, particularly carbamazepine, remains the primary option, many surgical interventions are available to provide pain relief. Microvascular decompression (MVD) has been the cornerstone of surgical therapy in the last decades. However, fewer options are available for patients without neurovascular compression (NVC) or with low-grade NVC. For those patients with limited surgical options, internal neurolysis (IN) is now being considered an option to provide pain relief. However, the longevity of pain relief and complications accompanying IN has yet to be established.

Methods: We conducted a retrospective review of patients treated at Thomas Jefferson University Hospital (TJUH) for TN who received IN as either stand-alone treatment or in conjunction with MVD. Through retrospective chart review, we collected data variables including pain scores using the Barrow Neurologic Institute (BNI) facial pain scale, and pre- and postoperative facial numbness scores using the BNI facial hypoesthesia scale, as well as general complications, following surgery. Facial numbness scores were collected during patient clinic visits and recorded in the electronic medical record (EMR). Postoperative complications were assessed through patient follow-up clinic visits and recorded in the EMR.

Results: A total of 23 patients treated at TJUH for TN via IN were identified via retrospective chart review. Fifteen patients received combination IN + MVD, and eight patients received IN alone. Preoperatively, 100% of patients rated their facial pain as IV or V on the BNI facial pain scale. Pain relief was obtained in 73% of patients receiving IN as stand-alone therapy and 93% of patients receiving IN + MVD at last follow-up. But 18 (78%) patients had no facial numbness and 5 (22%) had mild, nonbothersome facial numbness preoperatively. At last follow-up, 16 (70%) patients had mild, nonbothersome numbness and 6 (26%) had no facial numbness. Only one (4%) patient rated their facial numbness as mild, bothersome at last follow-up. Additional complications related to trigeminal nerve manipulation included corneal hypoesthesia seen in one (4%) individual. There were no reported incidents of anesthesia dolorosa. Incidence of eye dryness, tongue numbness and wound erosion were also reported.

Conclusion: IN shows promising pain-relief outcomes in a patient population with limited treatment options. While there is an increased rate of facial hypoesthesia, it doesn’t seem to affect patient quality of life. Serious adverse events remain rare, with very few cases of severe trigeminal nerve dysfunction. Further studies on IN are necessary to define the long-term pain and complication outcomes, and to determine its exact role in the armamentarium of TN therapies.