Cluster headaches, a disease belonging to the class of trigeminal autonomic cephalgias, are seen chronically in about 15% of all cluster headache patients.1,2 Affected individuals have always been treated with prophylactic medication, which generally led to unsatisfactory refraction rates.2 Hence, in 2001, the technique of deep brain stimulation (DBS) targeting the posterior hypothalamic region has been first suggested.3 Since then, a large number of prospective trials and case series using this technique have been published. Despite the growing number of positive evidence, the method’s effectiveness is still a matter of debate. Hence, Andreas Novacki (Department of Neurosurgery, University Hospital Bern, Switzerland) and his team recently published a systematic review and meta-analysis of individual patient data from cluster headache patients who underwent DBS in cohort studies.2
Original investigators involved in meta-analysis
Dr Novacki and his team asked the investigators of cohort studies with chronic cluster headache patients undergoing DBS to provide data of individual patients.2 The team managed to collect data from 40 individual patients from four different cohorts. This refers to around 48% of all previously published cases. Gathered data included baseline covariates, pre- and postoperative headache scores, long-term follow-up and individual imaging data. Out of the obtained data, the team constructed a stimulation map and estimated predictors of pain relief.
Long-term pain relief for patients confirmed
The overall result confirmed the previously reported positive effects of DBS in chronic cluster headache patients: over a mean follow-up time of 44 months, the authors found a 77% reduction in headache attack frequency.2 The number corresponds to an overall response rate of 75% of patients with a headache reduction of more than 50%. In addition, the analysis of the stimulation map yielded two particularly effective stimulation hotspots, covering the midbrain ventral and retrorubral tegmentum. The authors could not associate the outcome with any of the baseline covariates, and they could not identify patterns between DBS responders and non-responders.
New guidance for surgeons
This recently published meta-analysis impressively confirms the positive effects of DBS in the majority of chronic cluster headache patients. The authors state that their findings, especially the newly identified hotspot regions as optimal DBS target sites, can potentially help surgeons with their treatment decisions in the future. Their analysis set the base, but there will still be the need for a randomised controlled trial to confirm the effects of DBS in chronic cluster headache.