Introduction: Trigeminal neuralgia (TGN) is a debilitating disease with numerous potential treatments.
Many patients undergo stereotactic radiosurgery (SRS) as either initial or salvage
therapy. There is little known about which patients may poorly respond to SRS as initial
therapy and which of those failures may respond to more invasive modalities.
Objective: To identify which patients are most likely to fail SRS for treatment of TGN.
Method: This was a single-center, retrospective review of all adult patients with TGN who
underwent SRS as their initial treatment. We collected patient demographics, symptom
and treatment details, and Barrow Neurological Institute (BNI) pain outcomes data.
We performed Chi-square and independent student’s t-test for categorical and continuous
variables, respectively. Univariate regression analysis was performed to determine
odds ratios (OR). Multivariable regression analysis was performed for variables with
p < 0.10 or large effect sizes (OR ≥ 2.0 or ≤ 0.50) by univariable analysis.
Results: A total of 112 patients met inclusion criteria. Thirty (26.8%) patients required
additional treatment after initial SRS, including microvascular decompression (20,
66.7%), nerve ablation/rhizolysis (6, 20%), and redo SRS (4, 13.3%). Body mass index
(BMI) (p < 0.01), BNI pain score (OR: 2.29; 95% confidence interval [CI]: 0.26–19.85), trigeminal
pain distribution (p = 0.10), SRS modality (p = 0.07), and initial response to SRS (p = 0.06) were included in the multivariable model. BMI (OR: 0.91 [95% CI: 0.83–0.99])
and initial response to SRS (OR: 0.29 [95% CI: 0.08–0.99]) were significant by multivariable
regression analysis.
Conclusion: Predicting patients’ response to SRS remains challenging. Increasing BMI and any
initial symptomatic response to SRS may suggest a reduced risk of needing further
treatment. Initial BNI pain scores, Burchiel pain classifications, TGN symptomatic
duration, and the presence of any imaging abnormality did not predict symptomatic
response to SRS. It is imperative to counsel patients on the heterogeneous and unpredictable
response to SRS and to emphasize the need for further interventions for their TGN.
