Background & Aims
Central sensitization and impaired conditioned pain modulation (CPM) response has been reported to contribute to migraine progression. Migraine patients can present with allodynia possibly attributed to increased sensitivity of peripheral ends of nociceptors with both peripheral and central sensitization. Occipital nerve stimulation (ONS) is an established neuromodulation procedure for selected patients with medically intractable chronic cluster headache and migraine with autonomic symptoms. Although clinically effective, there has been no long-term outcome data on its effect on central sensitisation.
Efficacy outcomes for ONS typically employ standardised headache questionnaire measures but objective tests of endogenous pain mechanisms such as Quantitative Sensory Testing (QST) are yet to be utilised to measure efficacy of ONS. Our group has published one- year outcomes in central sensitisation following ONS. (Wodehouse et al, 2020).
Methods
The aim of this prospective study was to evaluate whether QST detects a change in pain in chronic migraine and provide more long-term outcome data in patients receiving ONS.
Six patients, 3 chronic migraine, 2 new persistent daily headache and 1 chronic cluster headache were implanted between 2014-2015 with percutaneous leads, placed bilaterally parallel to the greater occipital nerve, IPG (Genesis/ Prodigy St Jude Medical, Plano, TX,USA)/Medtronic ONS). Baseline QST and questionnaires were completed, and they were monitored up to a 12-month period and then annual review for 10 years.
Results
Patients with intractable migraine demonstrated reduced CPM in five out of six patients prior to ONS; reverting to “normal’ CPM response following ONS implant at 12 months and at ten years. In contrast pressure pain thresholds remained low throughout this per
Conclusions
This is first long term follow up in our knowledge investigating the effect of central sensitisation following ONS. Responders showed substantial reductions in headache-related disability and improvements in conditioned pain modulation over 10-year duration.
References
Changes in peripheral and central sensitization in patients undergoing occipital nerve stimulation.
Wodehouse T, Bahra A, Mehta V.
Br J Pain. 2020 Nov;14(4):250-255. doi: 10.1177/2049463719860548. Epub 2019 Jul 29