Background
Cluster headache (CH) is described by unilateral headaches of high intensity lasting from 15 to 180 min with a frequency of up to 8 attacks per day. A cluster headache is classified as an episodic cluster headache (ECH) when the period between the clusters is at least 3 months. Preventive treatment for refractory chronic cluster headache (rCCH) is challenging and many treatments have been tried.
Objective
To study what could be considered the treatment of choice in refractory chronic cluster headaches through a systematic review and meta-analysis.
Methods
- This review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines.
- A systematic search was conducted in Embase, Cochrane, clinicaltrials.gov, and the World Health Organization’s-International-Clinical-Trials-Registry-Platform.
- Studies on the preventive treatment for refractory chronic cluster headaches as defined by the European Headache Federation consensus statement were included.
- A meta-analysis of the pooled response rate was performed for the different therapies.
Results
- Out of 336 results, 45 were eligible for inclusion.
- Most articles studied the effect of neuromodulation as a preventive treatment for refractory chronic cluster headaches.
- The most studied neuromodulation technique is occipital nerve stimulation (ONS), with a pooled response rate in the meta-analysis of 57.3%.
- Deep brain stimulation (DBS) was the second most studied treatment with a pooled response rate of 77.0%.
- DBS results were more heterogeneous than ONS, which could be related to the different stimulation targets in DBS studies and reported more serious adverse events than in ONS studies.
- The remaining therapies (warfarin, ketamine-magnesium infusions, clomiphene) present weaker results or have less quality evidence.
Conclusion
The results of this systematic review and meta-analysis suggest that occipital nerve stimulation could be the first therapeutic method for patients with refractory chronic cluster headaches based on the current evidence.