せん妄を契機に顕在化した老年期甲状腺クリーゼの1例

Elderly Woman Presenting with Thyroid Storm with Delirium

抄録

　甲状腺クリーゼは稀とされるが，時に致死的経過をとる甲状腺中毒状態である。症例は74歳女性で健忘，情動不安定，体重減少，発熱を呈し当院を救急受診。髄液検査，頭部画像検査に異常なく認知症，肺炎の診断で近医にて加療継続された。その後情動不安定が続くため当科を受診し，せん妄状態により入院した。入院後心不全，消化器症状が顕在化し，精査にて甲状腺クリーゼと診断した。抗甲状腺薬の投与と全身管理により，甲状腺クリーゼおよびせん妄は消失したものの，認知機能の改善には約半年を要した。

　高齢化に伴い高齢者の甲状腺機能異常は増える可能性があり，高齢者のせん妄の原因として甲状腺クリーゼも念頭に置く必要があると考えられた。

　A thyroid storm is an unusual and life-threatening manifestation of thyrotoxicosis in elderly patients. We present the case of a 74-year-old woman who was sent to the emergency room with amnesia, agitation, weight loss, and fever. Cerebrospinal fluid examination, brain computed tomography, and magnetic resonance imaging revealed normal findings. The patient was diagnosed with dementia and pneumonia. Thereafter, she received medical treatment in the clinic. Three weeks later, the patient was admitted to our psychiatric department for agitation and delirium. After admission, the patient's clinical condition was aggravated by manifestations of cardiac failure and gastrointestinal symptoms. The laboratory findings were consistent with thyroid storm. The patient's general condition and delirium improved when thyroid function was returned to a euthyroid state by antithyroid treatment, but the dementia persisted. The patient's mental status improved gradually and finally returned to baseline after 6 months of antithyroid treatment after admission. Due to our aging society, thyroid disease in the elderly may increase in the future. Thus, a thyroid storm needs to be considered as a cause of delirium in elderly patients.