自己免疫性脳炎と睡眠障害

Autoimmune Encephalitis and Associated Sleep Disorders

自己免疫性脳炎では多彩な睡眠障害が生じる。抗NMDAR脳炎では急性期には不眠症を，回復期には過眠症やconfusional arousalを認める。抗LGI1脳炎や抗CASPR2脳炎で生じるMorvan症候群では，各睡眠段階の区別が曖昧となり，status dissociatusやagrypnia excitataを呈する。IgLON5抗体関連疾患では睡眠時パラソムニアのほか，睡眠時無呼吸や吸気性喘鳴をきたし突然死に至る例もある。視神経脊髄炎スペクトラム障害や抗Ma2脳炎では視床下部病変によりナルコレプシーを呈することがあり，オレキシン欠乏の関与が示唆されている。

Abstract

Autoimmune encephalitis can cause various sleep disorders. Anti-NMDAR encephalitis often presents with insomnia in the acute phase, which may transition into hypersomnia or confusional arousal during recovery. Anti-LGI1 and anti-CASPR2 encephalitis can also cause Morvan's syndrome. This syndrome is characterized by blurred distinctions between sleep stages, leading to status dissociatus and agrypnia excitata. Anti-IgLON5 disease is associated with parasomnia, sleep apnea, and stridor, all of which can lead to sudden death. NMOSD and anti-Ma2 encephalitis may present as narcolepsy accompanied by hypothalamic lesions, likely due to orexin deficiency.