Objective.-To study the frequencies and characteristics of different headache types seen in patients with Behcet's syndrome (BS) in a large cohort of patients.

Background.-Patients with BS may present with different neurological problems, related either directly or indirectly to the disease, with headache being the most common neurological symptom seen in this syndrome, as well as independent from neurologic involvement.

Method.-This study was carried out at the multidisciplinary Behcet outpatient clinic of the Behcet's Syndrome Research Center. Every fifth admitted patient who had fulfilled the International Study Group for Behcet's Disease classification criteria was recruited for this study. Each patient was interviewed by one of the examining neurologists through a semistructured questionnaire. In case of the presence of more than one headache type, the best defined one was diagnosed and evaluated. All patients received a complete neurological and physical examination. A X 2 test was used to evaluate the differences between frequencies. One sample t-test was used to compare means. The prevalence rates of primary headaches were compared with results of the Turkish Headache Epidemiology study by using goodness-of-fit test.

Results.-Two hundred and twenty-eight patients were studied. Headache was reported in 66.2% (151/228) of the study cohort. Primary headaches were seen in 38.6% of the patient population, which corresponds to 58% of BS patients with any type of headache. Tension-type headache (TTHA) and migraine were seen in 23.6% and 14.9% of the whole study cohort, respectively. In 5.2% of the study cohort, the headache was associated with neurological involvement and in 3.9% to uveal inflammation. A predominantly frontal, bilateral paroxysmal throbbing pain of moderate severity was reported in 18.4% of the study cohort who did not fulfill the criteria of the International Headache Society (IHS) for any of the primary headaches. It was commonly associated with exacerbations of the mucocutaneous symptoms of the syndrome. The neurological examination was normal in all of these patients. This type of headache was categorized as the nonstructural headache of Behcet.

Conclusion.-Headache is the most common neurological symptom seen in BS, both in patients with and without neurological involvement. The results of our study reveal that headache is seen in a majority of patients with neurological involvement due to BS and in a minority with uveal inflammation. The prevalence of migraine and TTHA are close to the population in general, but a nonstructural migrainous headache, which is commonly associated with exacerbations with some of the systemic symptoms of the syndrome, is noteworthy in patients with BS. This form of headache is not specific for this disorder, but may be explained by a vascular headache triggered by the immunomediated disease activity in susceptible individuals