Pregabalin as a salvage preoperative treatment for refractory trigeminal neuralgia

Only few studies have investigated the effectiveness of pregabalin (PGB) treatment for trigeminal neuralgia (TN). We aimed to retrospectively analyze the effectiveness of PGB treatment in refractory TN as a salvage treatment preceding surgery. Of 61 patients with TN refractory to prior treatment with carbamazepine (CBZ), we enrolled 33 patients in our study who agreed to receive PGB before they underwent surgery. The patients were divided into effective and ineffective groups depending on the patient-reported outcome. Correlations between effectiveness and clinical characteristics such as the age, sex, disease duration, initial CBZ responsiveness, the number of patients who underwent polytherapy with PGB and CBZ, final doses of CBZ and PGB at the time of evaluation, and the etiology of the neurovascular compression were statistically analyzed. Furthermore, a linear discriminant analysis was performed to predict effectiveness. TN was improved in 16 patients (48.5%) in the PGB-treatment group but none in patients without PGB-treatment. The final dose of PGB was 166.7 mg at the mean follow-up period of 5.5 months. Our results showed that age was the only factor that significantly differed between PGB-effective and ineffective groups. A logistic regression analysis also demonstrated that among all the clinical variables considered, only older age was significantly associated with effectiveness of PGB treatment. Effectiveness was correctly predicted at a threshold value of 62.7-years-old with 69.7% reliability. We suggest that PGB is useful, even at the low-dose, as a salvage preoperative treatment for patients with refractory TN, particularly for elderly patients.