高齢発症てんかんと脳卒中後てんかん

Elderly Onset Epilepsy and Post-Stroke Epilepsy

Point

・世界的に患者数の多い「高齢発症てんかん」では，実臨床での診断の難しさが示され，個々の症例に合わせて診察に工夫が必要である．

・治療は発作型に合わせた内服治療が中心となり，高齢者においては，薬物動態だけでなく，併存症にも配慮した「抗てんかん発作薬」の選択が求められる．

・病因として頻度の高い「脳卒中」では，てんかん病態につながる危険因子を探索することで，予防的投与につなげる可能性はうかがえるが，確立はしていない．

・ガイドライン上，全例に予防的投与を行うことは推奨されていないが，急性期に用いられていることは多く，特に高齢者では検討されることがある．

　It has been reported that the incidence of epilepsy in individuals over the age of 75 years is similar to or higher than one year, suggesting that epilepsy is an important clinical condition in older people. The aging rate in Japan, which reached 27.3% in 2017, makes this an issue of increasing concern. Diagnosis begins with the collection of medical history and knowledge of seizure semiology. In the elderly, most seizures are of extratemporal origin with various seizure semiologies. Difficulties in diagnosis lie in the influence of the autonomic nervous system and nonconvulsive status epilepticus（NCSE）. It is necessary to suspect “epilepsy” for any sudden-onset episodes of atypical symptoms and unusual behaviors. NCSE can be diagnosed by recording EEG for more than 6 hours. The narrow therapeutic window and pharmacokinetics complicated by aging make treatment much more difficult with anti-seizure medication（ASM）. Comorbidities and drug interactions should also be considered. Stroke is the most common etiology of geriatric epilepsy. Despite several clinical reports on the risk factors of post-stroke epilepsy（PSE）on the preventive administration of enzyme-inducing ASM, a treatment protocol has not yet been established. Prophylactic administration is not recommended; however, ASM is often administered in the acute phase. Therefore, some guidelines for non-enzyme-inducing ASM are required for efficient control of PSE.