Objective: First-line treatment for trigeminal neuralgia (TN) is pharmacological management using antiepileptic drugs (AEDs), e.g., carbamazepine (CBZ) and oxcarbazepine (OCBZ). Surgical intervention has been shown to be an effective and durable treatment for TN that is refractory to medical therapy. Despite the lack of evidence for efficacy in patients with TN, the authors hypothesized that patients with neuropathic facial pain are prescribed opioids at high rates, and that neurosurgical intervention may lead to a reduction in opioid use.
Methods: This is a retrospective study of patients with facial pain seen by a single neurosurgeon. All patients completed a survey on pain medications, medical comorbidities, prior interventions for facial pain, and a validated pain outcome tool (the Penn Facial Pain Scale). Patients subsequently undergoing neurosurgical intervention completed a survey at the 1-month follow-up in the office, in addition to telephone interviews using a standardized script between 1 and 6 years after intervention. Univariate and multivariate logistic regression were used to predict opioid use.
Results: The study cohort consisted of 309 patients (70% Burchiel type 1 TN [TN1], 18% Burchiel type 2 [TN2], 6% atypical facial pain [AFP], and 6% TN secondary to multiple sclerosis [TN-MS]). At initial presentation, 20% of patients were taking opioids. Of these patients, 55% were receiving concurrent opioid therapy with CBZ/OCBZ, and 84% were receiving concurrent therapy with at least one type of AED. Facial pain diagnosis (for diagnoses other than TN1, odds ratio [OR] 2.5, p = 0.01) and facial pain intensity at its worst (for each unit increase, OR 1.4, p = 0.005) were predictors of opioid use at baseline. Neurosurgical intervention led to a reduction in opioid use to 8% at long-term follow-up (p < 0.01, Fisher's exact test; n = 154). Diagnosis (for diagnoses other than TN1, OR 4.7, p = 0.002) and postintervention reduction in pain at its worst (for each unit reduction, OR 0.8, p < 10-3) were predictors of opioid use at long-term follow-up. On subgroup analysis, patients with TN1 demonstrated a decrease in opioid use to 5% at long-term follow-up (p < 0.05, Fisher's exact test), whereas patients with non-TN1 facial pain did not. In the nonsurgical group, there was no statistically significant decrease in opioid use at long-term follow-up (n = 81).
Conclusions: In spite of its high potential for abuse, opioid use, mostly as an adjunct to AEDs, is prevalent in patients with facial pain. Opportunities to curb opioid use in TN1 include earlier neurosurgical intervention.
Keywords: ADL = activities of daily living; AED = antiepileptic drug; AFP = atypical facial pain; CBZ = carbamazepine; GKRS = Gamma Knife radiosurgery; MCID = minimum clinically important difference; MVD = microvascular decompression; OCBZ = oxcarbazepine; OR = odds ratio; PFPS = Penn Facial Pain Scale; TN = trigeminal neuralgia; TN-MS = TN secondary to multiple sclerosis; TN1 = Burchiel type 1 TN; TN2 = Burchiel type 2 TN; fADL = face-specific ADL; facial pain; functional neurosurgery; gADL = general ADL; opioids; trigeminal neuralgia.