脳梗塞による失語症の言語機能と局所脳血流量の相関

Correlations of cerebral blood flow with language function in aphasic patients following cerebral infarction

　言語に係わる脳機能の局在を脳循環代謝量の分布から明らかにする目的で，脳梗塞による右利き失語症患者97例を対象に，標準失語症検査（SLTA）で評価した言語症状と，Positron emissiontomography（PET）による局所の脳血流量（cerebral blood flow：CBF）の相関関係を検討した。脳梗塞の発症から平均71.4±107.3病日にPETを施行した。回帰分析により，失語症状の成績と脳の55ヵ所のCBFとの相関関係を検討した。左前頭葉，側頭葉，頭頂葉のCBFは，聴く，話す，読む，書く，計算および復唱の言語の成績と有意の相関を認めた。左下前頭回後部，左上側頭回後部，左縁上回や左角回はより高い相関を認めた。聴く，話す，読む能力は右下前頭回後部，右L側頭回後部，右海馬傍回や右帯状回前部のCBFとの相関がみられた。本検討の結果から，言語機能やその回復過程には古典的な言語領域が中核的な役割をなし，さらに広範な左半球および右半球の一部が関与する可能性が示唆された。

To elucidate the participation of the brain regions in language function, cerebral blood flow (CBF) which were measured with positron emission tomography (PET) were compared with the language scores based on the standard language test for aphasics in 97 right-handed patients with aphasia due to cerebral infarction. PET studies were performed on 71.4 ± 107.3 days after onset. By the linear regression analysis, the aphasic scores were correlated with the regional CBF from 55 brain regions. CBF from the left frontal, left temporal, and left parietal lobes significantly correlated with language scores of auditory comprehension, speaking, reading, writing, calculation, and repetition. Highly significant correlation was obtained from the left posterior inferior frontal, superior temporal, supramarginal and angular gyri. CBF from the right inferior frontal, right superior temporal, right parahippocampal and right anterior cingulate gyri also correlated with the auditory comprehension, speaking and reading. Accordingly, in addition to the classical language areas which play an essential roles in language function, the extensive areas in the left hemisphere and some part of the right hemisphere may be related to the language processing and recovery from aphasia.