[Clinical profile of cluster headaches in Japan]

This study examined the clinical profile of cluster headache (CH) in Japan and the potential presence of features peculiar to Japan. Subjects comprised 110 consecutive new CH patients (83 males, 27 females; mean age, 38.1 ± 11.7 years). While 85% of patients had visited other medical institutions, only 19% had received a correct diagnosis. Mean delay in diagnosis was 8.1 years. The common clinical features of the present report and previous Japanese reports were as follows: 1) a low prevalence of chronic CH; 2) a low prevalence of sense of restlessness; 3) an uncoupling of a sense of restlessness and restless behavior; 4) approximately half of all patients experiencing CH attacks ranging in duration from 1-2 hours; 5) the location of CH most commonly reported as retro-orbital; and 6) lacrimation representing the most consistently reported autonomic feature. The common clinical features from 1) to 3) were seen in other East-Asia countries. Both frequencies of locations of CH and autonomic features differed between Caucasian and East-Asian populations. These characteristics may reflect ethnic and/or cultural differences between Eastern and Western CH patients.