初期に失声が見られ発語特徴がaphemiaに一致した左利きの右病変によるブローカ失語例

Case Report: Broca's Aphasia in a Left-Handed Patient with a Right Brain Infarction and Early Stage Aphonia

初期に失声があり，わずかな音素や単語以外発語のないタイプのaphemiaに表出特徴が一致する左利き右大脳梗塞のブローカ失語例を報告する。病巣は右中心前回下部と中・下前頭回を含み，発語の乏しさは音韻過程やその出力の断絶か発語開始の障害と考えた。このタイプのaphemiaが，症状や病巣の点で発語失行に相当するタイプと異なり，これに対応してブローカ失語の表出面に複数の機序がある可能性を示した。失語は側性化と局在ともに変則的で，麻痺の病態無関心などと二重症状を成し，上肢の行為障害は言語性半球内解離性失行の可能性がある。

Abstract

We report a case of Broca's aphasia in a left-handed patient with a right brain infarction. The patient's speech is consistent with a particular type of aphemia, that is, without vocalization except for a few phonemes or words. The patient presented with aphonia in an early stage. The lack of speech could be due to the impairment of the phonological-speech process or speech initialization. This type of aphemia has been reported to involve the right inferior precentral gyrus or right middle and inferior frontal gyri. Our patient had both lesions. The symptom and the lesion of this type of aphemia could differ from those of another type of aphemia corresponding to apraxia of speech, and the speech of Broca's aphasia could have multiple mechanisms. Our case shows Alexander's anomalous type with atypical lateralization and distribution of the lesion. Verbal intrahemispheric dissociation apraxia was suspected in our patient. The coexistence of aphasia, anosodiaphoria of hemiplegia is a dual symptom in which bilateral hemispheric functions exist in a unilateral hemisphere.

(Received 1 December, 2021; Accepted 1 February, 2022; Published 1 April, 2022)