Letter to the Editor regarding article: “Endoscopic surgical treatment for rhinogenic contact point headache: systematic review and meta-analysis”

Abstract

I have read with great interest the meta-analysis “Endoscopic surgical treatment for rhinogenic contact point headache: systematic review and meta-analysis” published in a recent issue of the European Archives of Oto-Rhino-Laryngology. The authors chose to analyse the truly important and controversial subject of headache and facial pain attributed to contact point within the nasal cavity. However, several points in this analysis call for a comment from the headache specialist perspective. First, it should be stressed that headache attributed to mucosal contact point (MCP) is not as yet recognised by the International Classification of Headache Disorders. The current 3rd version mentions headache attributed to disorder of the nasal mucosa, turbinates or septum. However, this type of headache is included only in the appendix with too little evidence for its existence [1]. There are no studies which have shown that occurrence of MCP increases the risk of headache. Moreover, a considerable group of rhinologists doubt its existence [2]. But there is another side to MCP headache: many surgeons indicate excellent results of interventions targeted at MCP removal. The number of studies describing surgery targeted at MCP far exceeds endoscopic trials included by Maniaci et al. Unfortunately, meta-analysis of evidence in this field is challenging, since the majority of studies are of low value according to evidence-grading systems. However, there exist several prospective controlled randomized trials (level 2B according to Centre for Evidence-Based Medicine). In this context, selection criteria of this metaanalysis seem to be too inclusive—authors chose to mix the results from higher grade studies with uncontrolled case series (level 4). This approach allows for higher participants numbers, but must consequently lead to depreciation of this meta-analysis’ scientific value. There are also other issues regarding study selection in this meta-analysis. According to Maniaci et al., ‘the studies included only clinically confirmed cases of rhinogenic point of contact headache’. Yet that seems to be inaccurate, as the authors of four included trials state that they recruited subjects with primary headaches (mostly refractory migraine) [3–5]. These authors do not confirm a clinical diagnosis of MCP headache. Some of them explicitly state that they believe MCP was the trigger and/or cause for refractoriness of migraine and not a separate rhinogenic headache [3, 4]. Also difficult to justify is the inclusion in this meta-analysis of the study by Guyuron et al. [6]. Not only this study specifically targeted subjects with migraine, but also nasal surgery was just one of many surgical interventions performed. The number of subjects that had nasal surgery in that study was lower than the number included in the meta-analysis. In conclusion, there are strong indications that MCP surgery may become a viable option in headache medicine in the future. Yet the selection process in this meta-analysis prevents conclusions regarding whether MCP surgery should be used in MCP (rhinogenic) headache, migraine or both. Moreover, as there are no sham surgery controlled trials included, we must further await a definite confirmation of MCP surgery effectiveness. The results might yet be surprising, if we draw an analogy to balloon sinuplasty, where surgery was no better than a sham in reducing sinus headache/ pressure [7].