[Stereotactic radiosurgery in treatment of trigeminal neuralgia]

It was not until relatively recently that the method of stereotactic radiosurgery has started to be used for treating trigeminal neuralgia. Being minimally invasive, this method can be considered an attractive alternative to invasive surgical methods.

The objective of this study was to analyze the results of treatment in patients with trigeminal neuralgia using the Leksell Gamma Knife system.

The results of stereotactic radiosurgery were analyzed in 52 patients (31 females and 21 males aged 31 to 79 years) who had undergone treatment at the Radiosurgical Center of MIBS (St. Petersburg) in 2009-2016. Forty-four patients were diagnosed with typical trigeminal neuralgia; four patients, with atypical neuralgia; and four patients, with symptomatic neuralgia (accompanying multiple sclerosis). Pain severity was assessed using the Visual Analogue Scale (VAS) and the Barrow Neurological Institute Scale (BNIPS) before and after the surgery, as well as during the follow-up period (mean duration, 3 years).

Pain was reduced in 38 (86.4%) patients with type 1 neuralgia. The effect usually was not observed immediately after the surgery but was delayed from several weeks to 12 months (median, 2 months; interquartile range) [1, 4]. The surgery was ineffective in 6 (14%) patients. Eight (18%) patients had a relapse on average after 2 years and 5 months. By the end of the follow-up period, score I according to the BNIPS was achieved in 22 (50%) patients; score II or III was achieved in 7 (16%) patients. Primary reduction of pain was achieved in two patients with type 2 neuralgia; one of them had a relapse after 19 months. Among patients with symptomatic neuralgia, the primary effect was achieved in three patients, but two of them later had a relapse.

Stereotactic radiosurgery can be used to alleviate pain in most patients with type 1 trigeminal neuralgia, but its results are inferior to those of invasive interventions. According to our findings, 18% of patients had a relapse. For patients with multiple sclerosis accompanied by type 2 and symptomatic trigeminal neuralgia, this method is not sufficiently effective. When both microvascular decompression and stereotactic radiosurgery can be used to treat for type 1 and 2 trigeminal neuralgia, patient's choice is crucial. It is important to inform the patient both about the potential complications of the interventions and about the delayed effect of the surgery and relapse frequency.