Effectiveness of thalamotomy with Gamma Knife radiosurgery as a multitarget strategy in patients with complex trigeminal neuralgia

Background: In the setting of refractory neuralgia or other complex facial pains, the intensity of the pain does not decrease despite medical and even surgical interventions. This report aims to describe the experience of an institution in the management of refractory trigeminal neuralgia and other complex facial pains with Gamma Knife radiosurgery (GKR), including thalamotomy as a multitarget strategy.

Methods: We conducted a retrospective observational study. Data were obtained from 50 patients with complex trigeminal neuralgia treated with GKR, in whom the thalamus was included as a target. The Visual Analog Scale (VAS) and the Barrow Neurological Institute (BNI) scale were considered before treatment and at the follow-up. The Wilcoxon test was used to compare the VAS scores and the McNemar test for the BNI scale.

Results: The mean age was 62.7 years (standard deviation = 16.3). The indications for management with thalamotomy were neuralgia refractory to medical management (68%), recurrent pain after previous rhizolysis with GKR (20%), atypical deafferentation-type pain in patients with radiofrequency background (10%), and anatomical deformation of the trigeminal nerve by a tumor (2%). Before treatment, all patients were classified as BNI V. At follow-up, a satisfactory response to treatment was described in 82.05% of cases (P = 0.001 McNemar). The median preoperative pain evaluated with VAS was 10 (interquartile range [IQR] = 10-10), while at follow-up, it was 6 (IQR = 1-7) (P = 0.001 Wilcoxon).

Conclusion: The thalamus is a versatile, effective, and safe therapeutic target for ablative management in patients with complex facial pain.