2. Methods

Patients with a diagnosis of FMF who had been following in a tertiary clinic of Pediatric Rheumatology Research Center for at least one year and who were in remission period were included in this study. The definite diagnoses of FMF were made by the same pediatric rheumatology expert according to the clinical characteristics and laboratory findings of the patients and depending on the definition criteria [20]. Patients were recruited during a clinical visit in pediatric rheumatology and were randomly referred to neurology clinic for the assessment of headache existence. Informed consent was obtained from the parents according to the procedures of the institutional review board. Data were collected from one parent, who was accompanying to the child. The evaluation of headache was done by a neurologist specialized with headache disorders using the ICHD diagnostic criteria (ICHD-2013). Patients were selected if they had either migraine or tension type headache (TTH) for at least 6 months; regarding the frequency and duration, intensity, localization, quality of pain, associated symptoms, and aggravating factors of each headache. The final diagnosis of headache was made by another neurologist according to the International Classification of Headache Disorders-II (ICHD-II)[21] during face-to-face interviews. Neurological examinations were performed by neurologists under the supervision of a specialized neurologist from the Headache Center. Patients with abnormal neurological examination and any neurological disorder were excluded. We only selected patients with TTH and migraine diagnosis, for at least 6 months and have attack frequencies of at least once a month. Participants meeting all but one of the diagnostic criteria for a given headache subtype were classified as ‘probably’having that headache type. Those diagnosed as migraine or probable migraine were considered to have migraine and those classified as TTH or probable TTH were considered to have TTH.