拡張型心筋症と脳塞栓症を合併したBecker型筋ジストロフィー

Cerebral Embolism Associated with Becker Muscular Dystrophy-related Dilated Cardiomyopathy

　要旨　症例は65歳男性。40歳時労作時呼吸困難が出現し，拡張型心筋症（DCM）と診断された。54歳時に近位筋優位の四肢筋力低下が出現し，Becker型筋ジストロフィー（BMD）と診断された。心不全増悪のため入院した際，突然の失語と右片麻痺が出現した。頭部MRIでは左中大脳動脈・上下小脳動脈領域に梗塞像を認めた。心エコー上高度の心不全を呈していたが，心内血栓はなかった。入院時心電図は洞調律であったが，脳梗塞発症時には心房細動に変化していた。BMDに合併したDCMを背景に心房細動に移行したことによる心原性脳塞栓症と診断した。BMDでは骨格筋症状と心筋障害の重症度が相関しない場合があるため，心原性塞栓症の発症に留意する必要がある。

　A 65-year-old man with previous history of congestive heart failure and genetically proven Becker muscular dystrophy（BMD） was suddenly suffered from aphasia and right hemiplegia. Physical examination showed severe motor aphasia, right hemiplegia, and signs of left heart failure. An echocardiogram before the onset of aphasia showed markedly dilated left ventricle and decreased ventricular contraction. Intracardiac thrombus was not detected. Although his electrocardiogram on admission showed sinus rhythm, atrial fibrillation was noted at the time of neurological deterioration. MRI of the brain revealed acute infarction in the territory of the left middle cerebral artery and the left anterior inferior cerebellar artery. MR angiography showed vascular occlusion at the left M2 segment. Cerebral embolism due to atrial fibrillation associated with BMD-related DCM was diagnosed. While an administration of anti-coagulant, diuretics, and dopamine relieved his respiratory distress and right hemiplegia, severe motor aphasia persisted. Cerebral embolism may be a notable complication in patients with BMD presenting with late-life expression of skeletal muscular weakness and antecedent cardiac involvement.