The rare, unilateral headaches. Vågå study of headache epidemiology.

In the Vågå study of headache epidemiology, 1838 parishioners in the age group 18-65 years were included (88.6% of the relevant population). Each individual was questioned in a face-to-face situation. In this population, a search of rare unilateral headaches was also made, in spite of their presumed rarity. Trigeminal neuralgia was present in two cases. Two individuals with SUNCT traits were observed. Hemicrania continua may have been present in one individual. Also observed were: optic neuritis (n=1), herpes zoster (n=4); a case of unilateral headache upon neck rotation (chronic paroxysmal hemicrania variant? or "forme fruste" of the neck-tongue syndrome?); masseter muscle spasm (n=1); temporo-mandibular joint dislocation (n=1); and possible carotidynia (n=3). A particularly intriguing form of headache was a unilateral, neuralgiform (?) pain, associated with ipsilateral, regular jabs and allodynia, a combination observed in eight females. A couple of conditions that entirely defy rubrication are also reported.