Nummular Headache and Its Surgical Treatment

Nummular headache (NH) is an uncommon primary headache characterized by pain limited to a precise small area of the scalp. There is no global consensus on its pathogenesis, but its extracranial origin is the most accepted theory. Moreover, peripheral mechanism is supported by the overlapping symptomatology of secondary forms of NH and is well described in the literature. However, a standard effective treatment is still lacking. METHODS: A literature search according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines was conducted to evaluate surgical strategies for NH. Inclusion criteria were English language, diagnosis of primary NH according to International Classification of Headache Disorders, 3rd Edition, or of secondary NH, and follow-up at a minimum of 3 months. The treatment had to consist of peripheral surgery. RESULTS: One hundred eighty-seven records were identified after duplicates were removed, 15 full-text articles were assessed for eligibility, and 4 records were selected for inclusion. A total of 53 patients were included in this review, 50 of whom were diagnosed with primary NH. The general positive response after surgery (>50% reduction in occipital migraine headaches) was about 70.0% for primary NH, while secondary NH always showed complete pain relief. However, many variations in patient selection and type of surgery were described. CONCLUSIONS: Neurovascular relationship in the extracranial tissues seems to be involved in the onset of NH. However, only limited data from meager literature and from few patients are currently available. Shared multicentric research protocols are badly required.