Burden of seizures and comorbidities in patients with epilepsy: a survey based on the tertiary hospital‐based Epilepsy Syndrome Registry in Japan

Objective. To examine the current medical and psychosocial status of patients with epilepsy, aiming to facilitate appropriate application of the Intractable/Rare Diseases Act of Japan. Methods. By analysing the cross‐sectional data of patients registered in the tertiary hospital‐based Epilepsy Syndrome Registry of Japan, we investigated the proportion of patients who met the severity criteria as defined by the Act (seizure frequency of at least once a month, or presence of intellectual/neurological/psychiatric symptoms, or both) and whether there are candidate syndrome/diseases to be added to the existing list in the Act. Results. In total, 2,209 patients were registered. After excluding self‐limited/idiopathic epilepsies, 1,851 of 2,110 patients (87.7%) met the severity criteria. The patients were classified into eight main epilepsy syndromes (594 patients), 20 groups based on aetiology (1,078 patients), and three groups without known aetiology (427 patients). Most of the groups classified by syndrome or aetiology had high proportions of patients satisfying the severity criteria (>90%), but some groups had relatively low proportions (