左手の拮抗性失行にかかわらず，右手の不自由さを主訴とした脳梁離断症候群の1梗塞例

A Case of Callosal Disconnection Syndrome with a Chief Complaint of Right-hand Disability,Despite Presence of Left-hand Diagonistic Dyspraxia

はじめに

　手術による脳梁の切断，もしくは腫瘍，梗塞などの脳梁病変により，左右大脳半球間の連絡経路が断たれ，脳梁離断症候群と呼ばれるさまざまな高次脳機能障害が起こることが報告されている。われわれが渉猟し得た限り，随伴病変のない脳梁梗塞により高次脳機能障害を呈した症例は少ない^1－5）。今回われわれは，脳梁に限局した梗塞により典型的な脳梁離断症候群を呈し，かつこれまでに報告のないさまざまな症候がみられた興味深い症例を経験したので報告する。

Abstract

　We report the case of 48-year-old right-handed male patient with an infarction affecting most part of the body and the splenium of the left half of the corpus callosum.　Neuropsychological examination revealed typical signs of callosal disconnection including left-sided apraxia, diagonistic dyspraxia, left-sided agraphia, left-hand tactile anomia, left hemialexia, and right-sided constructional disability.　Moreover, he complained of impairment in activities involving the right hand disability and agraphia.　He could not stop behaving with his right hand when he had a vague idea.　For example, he involuntarily picked up a tea bottle with his right hand when he had a desire to drink, although the action was not appropriate to that occasion.　The imitation and utilization behavior did not imply this case, because his right hand behaviors were not exaggerated in response to external stimuli, such as the gestures of the examiner or the subjects in front of the patient.　Unexpectedly, he complained about impairment of the activity of his right hand and was unaware of left hand apraxia or diagonistic dyspraxia; this trend continued for 6 months, at the time of this writing.　We argue that the patient may have been subconsciouly aware of the symptoms of his left hand but had not verbalized them. (Received: August 31,2007,Accepted: August 25,2008)