Long‐Term Response of Occipital Nerve Stimulation on Central Sensitization in Patients With Chronic Primary Refractory Daily Headache: A Pilot Study

ABSTRACT Background Central sensitization and impaired conditioned pain modulation (CPM) response have been associated with chronic migraine. Consequently, migraine patients can present with allodynia. Occipital nerve stimulation (ONS) is a neuromodulation procedure used in patients with refractory chronic primary headache disorders such as cluster headaches and migraines. We report on long‐term outcome data on the effects of ONS on central sensitization. Efficacy outcomes for ONS typically employ standardized headache questionnaire measures. However, more objective tests of endogenous pain mechanisms, such as Quantitative Sensory Testing (QST), have not been utilized to measure whether reported outcomes are paralleled by QST changes following the long‐term implementation of ONS. Our group has published one‐year outcomes in central sensitization following ONS. Objective This prospective study aimed to evaluate whether QST detects a change in central sensitisation in patients with refractory chronic primary headache and provides more long‐term outcome data for patients receiving ONS. Methods Six patients, three new persistent daily headaches, two chronic migraines, and one chronic cluster headache were implanted between 2013 and 2015 with percutaneous leads placed bilaterally parallel to the greater occipital nerve; IPG was a Genesis/Prodigy St Jude Medical, Plano, TX, USA now Abbott systems. Baseline QST and questionnaires were completed and monitored for up to 12 months and then annual review for 10 years. Results Patients showed substantial reductions in headache‐related disability and quality of life measures. Patients demonstrated impaired/reduced CPM in all but one patient at baseline, and this reverted to an increased CPM at 12 months. Then, this was maintained at the 10‐year visit. Conclusion This is a long‐term prospective follow‐up investigating the effect on central sensitization following ONS implantation. Responders showed substantial reductions in headache‐related disability and improved conditioned pain modulation over a 10‐year period.