Comparative Study between Intravenous Ketamine and Lidocaine Infusion in Controlling of Refractory Trigeminal Neuralgia

Abstract

Background: Trigeminal neuralgia (TN) is considered one of the most debilitating disorders. Several medications such as anticonvulsants are available to provide relief from pain. In this study we used either ketamine which acts as an antagonist to N-methyl-d-aspartate receptors, or lidocaine which can block sodium channels in controlling of refractory trigeminal neuralgia.

Continuous Ketamine Infusion as a Treatment for Refractory Facial Pain

“…There is limited research to guide the use of continuous or intermittent ketamine for chronic neuropathic or nonneuropathic chronic pain [19]. Inpatient monitoring during continuous ketamine infusion in the current study allowed the safe delivery of a higher dose of ketamine compared to intermittent ketamine infusion [13]. There are known biological mechanisms consistent with the notion that continuous ketamine infusion may lead to better analgesia in the perioperative period and may be more suited than intermittent boluses in treating conditions related to central sensitization [9,20].…”

“…However, when the admission diagnoses were analyzed, it was noted that patients with TN were more likely to respond to ketamine infusion compared to patients with AFP (Chi-square = 5.18, df = 1, p = 0.023; odd ratio = 24, 95% CI = 1.14-505.22, p = 0.041) as shown in Table 2. Furthermore, the responder group appeared to have a younger average age compared to the non-responder group, although this was not statistically significant (49.9 ± 12.7 vs. 62.8 ± 5.9, p = 0.062) as shown in Table To better characterize the degree of pain relief from continuous ketamine infusion, the change in pain scores of the responder group was compared with previously published data [13]. Adopting the historic data from the study of Mogahed et al on the efficacy of intermittent ketamine infusion for TN patients (e.g., two hours of infusion at a dose of 0.4 mg/kg every four days for three sessions), patients in our responder group, who were predominantly TN patients, had a greater reduction in pain scores compared to the patients who received intermittent ketamine infusion (n = 7, -6.4 ± 2.3 vs n = 50, -3.2 ± 0.6, respectively, df = 36, p < 0.001).…”

“…Despite its efficacy as a general analgesic, the literature on ketamine infusions for refractory facial pain is limited. Intramuscular or parenteral infusion of ketamine has been associated with neuropathic pain relief in chronic orofacial pain, migraines, acute pain after oral surgery, chronic regional pain syndrome (CRPS), and refractory TN [8,[12][13][14][15]. This current retrospective case series aimed to explore the clinical efficacy of continuous ketamine infusions in patients with refractory orofacial pain, particularly those with AFP or TN, and identify key clinical characteristics that were associated with treatment responders and non-responders.…”