他の神経症状に乏しく重度嚥下障害を呈した延髄内側梗塞

Isolated Severe Dysphagia Associated with Medial Medullary Infarction: A Case Report and Review of the Literature

症例は59歳男性。突然の回転性めまいと吐き気で発症し，数時間後には嚥下障害のため経口摂取がまったく不可能になった。神経学的には重度の嚥下障害を認め，他の神経症状に乏しく，急性期に軽度の左顔面神経麻痺と頸部以下右側の表在感覚障害がみられたのみで，四肢の運動麻痺，協調運動障害もみられなかった。頭部MRIの拡散強調画像で延髄吻側の左内側部に前後方向に長い高信号域を認め，延髄内側梗塞急性期と診断した。その後，顔面神経麻痺や感覚障害は2週間後には消失し，舌・軟口蓋，咽頭筋の麻痺を認めないにもかかわらず，重度の嚥下障害のみが残存し，遷延した。本症例の障害部位は，解剖学的にヒトにおける狭義の嚥下中枢（central pattern generator）を含んでいる可能性が高い。その症候を提示し，解剖学的考察を加え報告する。

Abstract

A 59-year-old man developed a sudden onset of vertigo and nausea, and after a few hours, he could not swallow at all. On admission, neurological examination revealed severe dysphagia associated with other transient and mild neurological deficits, including left facial paresis, and hypesthesia in the right side of his body. MRI with diffusion weighted imaging showed a hyperintense signal lesion at the left rostral medial region of the medulla, prompting the diagnosis of an acute medial medullary infarction. His facial paresis and hypesthesia disappeared within 2 weeks. Despite lacking motor paralysis in the tongue, soft palate, and pharyngeal muscle, the patient had severe and prolonged dysphagia. It is speculated that the lesion in this patient is located at the central pattern generator (CPG), which is thought to be the human swallowing center.

(Received April 1, 2016; Accepted June 1, 2016; Published October 1, 2016)