Spain: A recent study published in the Journal of Neurology has highlighted the role of Occipital Nerve Stimulation (ONC) as the first therapeutic strategy for refractory chronic cluster headache (rCCH).
Cluster headache (CH) is a rare and severe form of headache with a circadian pattern. This type of headache is characterized by unilateral periorbital pain and untreated headache attacks (shorter than 3 hours). The condition shows male predilection.

The impacts of CH severity are socioeconomic, morbidity-associated, restricted daily activities, direct costs of healthcare services, indirect costs of lost workdays, and reduced work efficacy.
In Denmark, one of the studies mentioned that less than 50% of CH patients are treated by headache specialists, 30% report missed work, and 78% report daily activity restrictions. This points out that CH is a disabling painful condition.
Treatment plans have included verapamil, lithium, oral or iv steroids, topiramate, methysergide, ergots, and long-acting triptans. Greater occipital nerve infiltration is also a therapeutic option and requires an appropriate clinical experience. Patients may not respond to the mentioned treatments, and the cause remains unknown.
This urgent clinical situation led physicians and patients to try unusual treatments, but the evidence remains limited and sparse. There is a need to scientifically document the therapeutic options, including the invasive ones.
Considering this, a study was conducted by Dr. Javier A. Membrilla from the Neurology Department, "La Paz" University Hospital, Madrid, Spain, with a team of researchers to answer, What could be the therapeutic choice in rCCH?
The critical points of the study are:
• The researchers conducted a systematic review and meta-analysis.
• The database searched were MEDLINE, Embase, Cochrane, clinicaltrials.gov, and the WHO's-International-Clinical-Trials-Registry-Platform.
• The analysis included those studies which had preventive treatment for rCCH by the European Headache Federation consensus statement. Overall, 45 studies met the eligibility.
• The studies included the effect of neuromodulation for preventive treatment for rCCH.
• Occipital nerve stimulation (ONS) was the most studied neuromodulation technique and had a pooled response rate of 57.3 % in the meta-analysis.
• The second most studied treatment was Deep brain stimulation (DBS), with a pooled response rate of 77.0%.
• DBS results were more heterogeneous than ONS.
• The remaining therapies include serial occipital nerve blocks, warfarin, anti-CGRP pathway drugs, ketamine-magnesium infusions, clomiphene, onabotulinum toxin A, ketogenic diet, sphenopalatine ganglion radiofrequency or stimulation, vagus nerve stimulation, percutaneous bioelectric current stimulation, upper cervical cord stimulation, and vidian neurectomy presented with weaker results and they had less quality of evidence.
The researchers finally concluded that ONS could be the first therapeutic strategy for patients with rCCH based on the current evidence. The researchers acknowledged Blanca Fuentes for her guidance in the study.
Further reading:
Membrilla, J.A., Roa, J. & Díaz-de-Terán, J. Preventive treatment of refractory chronic cluster headache: systematic review and meta-analysis. J Neurol (2022).