Objective:

This meta-analysis aimed to evaluate the epidemiology of nummular headache (NH) among adults evaluated for a headache in a clinic-based setting and relative frequencies of clinical features of NH.

Background:

NH is a rare primary headache disorder which was first described in 2002. Since the first report, over 500 cases documented in the literature provide the bulk of our current knowledge regarding NH; nevertheless, the relative frequencies of essential clinical aspects remain unknown. Therefore, in light of the clinical significance, the objective of this study was to evaluate the key characteristics of NH.

Design/Methods:

Major databases were searched for studies reporting the relevant data regarding NH. Random-effects meta-analysis was performed in order to calculate the pooled prevalence estimates (PPEs). The PRISMA guidelines were strictly followed by the study’s structure. The JBI Checklist was used to evaluate the risk of bias of included studies

Results:

Out of initial 2,441 records, 17 studies met all of the inclusion criteria. The pooled mean age of onset of NH was 46.91 (95%CI:43.85–49.96). The PPE of NH in adult patients evaluated for a headache in a clinic-based setting was 0.7% (95%CI:0.2–2.4), with slight female predominance. The majority of patients (69.4%, 95%CI:58.1–78.8) experience chronic course of NH. The shape of the headache was round/circular in 78.4% (95%CI:71.9–83.7) and oval/elliptical in 21.6% (95%CI:16.3–28.1) of patients. In 7.5% (95% CI:2.7–19.0) of individuals, pain had multifocal location and 59.1% (95%CI:49.7–68.0) of NH patients experienced pain exacerbations. The pain was most prevalent in the strictly parietal region (43.0%, 95% CI:37.4–48.7) of the cranium and had pressing quality (51.4%, 95%CI:41.6–61.1).

Conclusions:

The results of our study showed that NH is a very distinct and relatively rare to encounter headache disorder. Due to its unique clinical phenotype, physicians need to be aware when a patient presents with a small, welllocalized round/oval headache in the cranium region.