Headache Frequency and Pain Severity Following a Nerve Stimulator Implant for Chronic Migraine: A Systematic Review and Meta-Analysis

Migraines affect approximately one billion individuals worldwide. Implanted nerve stimulator devices can provide relief to some individuals who have chronic migraines refractory to other treatments. This study defines the change in headache pain severity and headache frequency following implanted nerve stimulator treatment in chronic migraineurs. A PRISMA-compliant systematic review of six databases was performed to identify all clinical trials treating at least 10 chronic migraineurs with an implanted nerve stimulator. Inverse variance random effects meta-analyses were performed to define the relative change in headache pain severity and headache frequency as compared to baseline. Nine studies met criteria, including 5 randomized controlled clinical trials and 4 uncontrolled clinical trials, and treated 559 individuals. Among studies that reported gender, 306 females and 154 males were treated. Mean patient ages ranged from 45 to 50 years. All included studies targeted the greater occipital nerve with an implanted nerve stimulator. Implanted nerve stimulator treatment reduced pain severity at 1 month by 36.42% (95%-CI: 28.35-44.49, I² = 55%) and 3 months by 50.04% (95%-CI: 39.67-60.42%, I² = 26%). Implanted nerve stimulators reduced headache frequency by 49.86% (95%-CI: 31.49-68.23, I² = 92%) at 1 to 3 months and 27.43% (95%-CI: 17.68-37.18, I² = 63%) at 6 to 97 months. Implanted nerve stimulator devices provide clinically and statistically significant improvements in headache severity and frequency in individuals with chronic migraines.