Nummular headache: a series with symptomatic and primary cases.

Nummular headache (NH) is a primary headache adopting the form of local pain in a circumscribed area of < 7 cm in diameter in the tuber parietale, albeit it may also be located in other areas of the head. Although it is chronic, it is commonly associated with exacerbations and short periods of remission. Here we report four cases. Two of them could not be considered primary: in one the pain was related to an underlying, pointed and benign lesion disclosed only by magnetic resonance imaging (case 1); the second one had persistent NH days after trans-sphenoidal surgery for a pituitary adenoma, similar to a postcraniotomy headache (case 2). The two final patients suffered from typical forms of primary NH, one associated with migraine without aura, the other with chronic tension-type headache. The response to pain-related treatments and to preventive drugs was poor in the symptomatic as well as in the primary cases. The mechanisms are not clear, and peripheral (case 1) and also central pathways (case 2) could be involved. In the end, secondary forms of NH might coexist with classical primary NH. Particular attention should be paid to tiny skull lesions and to key events preceding the pain.