失語症の長期予後と発症時年齢

―長期経過後の言語機能および非言語機能について―

抄録

The purpose of the present study was to look specitically for the presence of subtle linguistic and nonlinguistic deficits that persist after left hemisphere lesions incurred during infancy or childhood, and to compare them with the ultimate outcome for the late onset aphasics (adult and geriatric aphasics) .
A battery of linguistic and nonlinguistic examinations was given to a total of 17 CVA patients divided into three groups, i. e., 5 child aphasics (younger than 15 years old at the time of onset) ; 6 adult aphasics (20 to 59 years at the time of onset) ; and 6 geriatric aphasics (older than 60 years at the time of onset) . Six normal elementary school children (mean age : 11.5) served as controls. The results of these examinations were compared among the three aphasia groups and analyzed in relation to the lesion information obtained by CT scan.
The results were as follows
1. Child aphasics as a group exhibited a superior performance for linguistic and communicative functions among the three groups. Nevertheless, child aphasics were significantly inferior to the normal control children especially on syntactic and reading tasks. Moreover, the chidren who incurred brain injury befory the age of three exhibited a severe limitation in nonlinguistic functions. Older children (with the onset of aphasia after the age of six) exhibited a more selective disorder of linguistic functions with some correspondence to the site of their lesion in the left cerebral hemisphere.
2. The adult aphasics exhibited selective disorders of linguistic functions corresponding to the site of their lesion in the left cerebral hemisphere.
3. The pattern of linguistic impairments in the geriatric aphasics did not always correspond to their lesion sites as obtained by CT scan. Some of the patients in this group exhibited disorders in nonlinguistic functions as well.
Based on these findings, underlying mechanisms for the differential recovery among the different age groups were suggested.