Peripheral nerve field stimulation is a safe, reversible, and effective treatment option for intractable headache and craniofacial pain, research presented at the 14th annual meeting of the North American Neuromodulation Society shows.
“The treatment of chronic migraines and neuropathic pain in the region of the head, neck and face presents a challenge for pain specialists,” said Paul Verrills, Metro Spinal Clinic, Caulfield South, Victoria, Australia. He explained that peripheral nerve field stimulation has been used to treat neuropathic pain for over a decade but only recently has it been applied systematically to the craniofacial region.
“Here we present a study of craniofacial peripheral nerve field stimulation, demonstrating an effective alternative to current pharmacological pain management strategies,” Verrills told delegates at Las Vegas in December 2010.
Investigators assessed 50 consecutive patients following a successful peripheral nerve field stimulation trial period over the course of 4.5 years. They implanted patients with percutaneous leads within the major area of craniofacial pain. Verrills and team used patient questionnaires and histories to assess outcomes such as pain (numerical rating scale), analgesic use, anxiety (State and Trait Anxiety Index), depression (Zung Depression Index) disability (Neck Disability Index) and satisfaction. They obtained ethics approval and patients consent, with a 100% follow-up rate and an average follow-up time of 10.
Verrills told delegates that results of the study showed that peripheral nerve field stimulation successfully provided pain relief of ≥25% in 84% of patients with permanent implants, which reduced pain levels by 4.8± 2.4 NRS (p≤0.05), and resulted in average pain relief of 62.6±26.4%. Over one-third of patients reported pain relief of ≥75%. Both depression and disability were reduced following implantation.
“Pain relief achieved at the beginning was sustained at follow-up intervals of ≤12 months. Complications were observed in 12 patients. They were: lead/anchor/suture erosion (9); hardware migration(1) and lead infection (2). Two-thirds of these patients achieved favourable outcomes following reposition and/or re-implantation, with only four patients opting for an explant,” Verillo said.
Also, approximately 50% of patients reported moderate to extreme reductions in analgesic use. Reduction in analgesic use inversely correlated with pain relief (r=0.75, p=≤0.05) and patient satisfaction (r=0.69, p≤0.05), with 80% of patients reporting satisfaction with their outcomes.