マンガン中毒を早期発見しよう—職業歴とMRI T1強調画像によって

Early Detection of Manganese Intoxication Based on Occupational History and T1-weighted MRI

マンガンは多くの酵素を制御し，正常細胞機能にとって必須である。慢性マンガン中毒は軽微な症状で発症し，進行すればパーキンソン病類似の錐体外路症候を呈し，治療反応は乏しい。溶接工などの職業歴を参考に，血中・尿中濃度が高くなくともキレート剤投与による尿中排泄量の異常増加で判定できる。さらに，MRI T₁強調画像における淡蒼球高信号の証明と併せ，早期発見が可能である。

Abstract

Manganese regulates many enzymes and is essential for normal cell function. Chronic manganese intoxication has an insidious and progressive course terminating to atypical parkinsonism with little therapeutic efficacy. For subjects with chronic manganese exposure such as welders, manganese intoxication can be detected early based on the presence of hyperintensity in the globus pallidus on T₁-weighted MRI and abnormally high urinary excretion of manganese with a chelating agent even in cases of normal serum/urine level of manganese.

—(Received June 25, 2015; Accepted August 31, 2015; Published February 1, 2016)