Stimulation of the Gasserian Ganglion for Trigeminal Neuropathic Pain Refractory to Medical Management

Background:Trigeminal neuropathic pain (TNP) is an often debilitating facial pain syndrome for which there is no known cure or effective treatment. It differs from its more commonly known counterpart, trigeminal neuralgia (TN), in that it is constant and does not have an anatomical etiology which would allow for surgical correction. TNP is frequently refractory to pharmacologic therapy using high dose antiepileptics. Previous attempts to use nerve stimulation as a treatment method involved invasive surgical techniques and frequent electrode migration. Methods: Exhaustive search of available medical literature was conducted using Clinical Key, MEDLINE-Ovid and Web of Science and the following search terms: trigeminal neuropathic pain, neuromodulation and stimulation. Articles were assessed for quality using GRADE criteria. Results: Two case series studies fit all eligibility criteria. Each utilized a temporary electrode placed for a trial period to assess efficacy and determine candidacy for permanent implantation. One study found that in those with a positive trial, 96.3% at 6 months and 46.7% of patients at 24 months experienced pain reduction from baseline. Another study found that 62.5% of patients with a positive trial experienced pain reduction at 6 months, with 37.5% still experiencing pain reduction at 12 months. Conclusion: Stimulation of the Gasserian ganglion (GG) may be an effective treatment for long-term pain reduction in TNP; however, current studies are of very low quality due to small cohort size and lack of an RCT. Keywords: Trigeminal neuropathic pain, Gasserian ganglion, trigeminal neuropathy, stimulation, neuromodulatio