Related Experiment Video
Updated: Jun 4, 2026
3D-Neuronavigation In Vivo Through a Patient's Brain During a Spontaneous Migraine Headache
Published on: June 2, 2014
Central modulation in cluster headache patients treated with occipital nerve stimulation: an FDG-PET study
Delphine Magis1, Marie-Aurélie Bruno, Arnaud Fumal
1University Neurology Department, Liège, Belgium.
Background:
Occipital nerve stimulation (ONS) has raised new hope for drug-resistant chronic cluster headache (drCCH), a devastating condition. However its mode of action remains elusive. Since the long delay to meaningful effect suggests that ONS induces slow neuromodulation, we have searched for changes in central pain-control areas using metabolic neuroimaging.
Methods:
Ten drCCH patients underwent an 18FDG-PET scan after ONS, at delays varying between 0 and 30 months. All were scanned with ongoing ONS (ON) and with the stimulator switched OFF.
Results:
After 6-30 months of ONS, 3 patients were pain free and 4 had a ≥ 90% reduction of attack frequency (responders). In all patients compared to controls, several areas of the pain matrix showed hypermetabolism: ipsilateral hypothalamus, midbrain and ipsilateral lower pons. All normalized after ONS, except for the hypothalamus. Switching the stimulator ON or OFF had little influence on brain glucose metabolism. The perigenual anterior cingulate cortex (PACC) was hyperactive in ONS responders compared to non-responders.
Conclusions:
Metabolic normalization in the pain neuromatrix and lack of short-term changes induced by the stimulation might support the hypothesis that ONS acts in drCCH through slow neuromodulatory processes. Selective activation in responders of PACC, a pivotal structure in the endogenous opioid system, suggests that ONS could restore balance within dysfunctioning pain control centres. That ONS is nothing but a symptomatic treatment might be illustrated by the persistent hypothalamic hypermetabolism, which could explain why autonomic attacks may persist despite pain relief and why cluster attacks recur shortly after stimulator arrest. PET studies on larger samples are warranted to confirm these first results.
Insights
Occipital nerve stimulation (ONS) may treat chronic cluster headaches by slowly modulating brain metabolism. This neuroimaging study found normalization in pain pathways, suggesting ONS restores balance in pain control centers.
Area of Science:
- Neurology
- Neuroimaging
- Pain Management
Background:
- Drug-resistant chronic cluster headache (drCCH) is debilitating.
- Occipital nerve stimulation (ONS) offers potential relief but its mechanism is unclear.
- Slow neuromodulation is hypothesized due to ONS's delayed effects.
Purpose of the Study:
- Investigate the neuromodulatory effects of ONS on central pain-control areas.
- Utilize metabolic neuroimaging to detect changes in brain activity.
- Explore the mechanism of action for ONS in drCCH.
Main Methods:
- 18FDG-PET scans were performed on 10 drCCH patients.
- Scans were conducted with ONS ON and OFF, at 0-30 months post-implantation.
- Brain glucose metabolism was analyzed in relation to ONS treatment duration and response.
Main Results:
- 3 patients achieved pain freedom, 4 had ≥90% attack reduction.
- Hypermetabolism in the hypothalamus, midbrain, and pons normalized post-ONS (except hypothalamus).
- Perigenual anterior cingulate cortex (PACC) hyperactivity was observed in responders.
Conclusions:
- ONS likely acts via slow neuromodulation, evidenced by metabolic normalization in pain pathways.
- PACC activation in responders suggests restored balance in endogenous opioid pathways.
- Persistent hypothalamic hypermetabolism may explain residual autonomic symptoms and recurrence after ONS cessation.
