In five patients with aphasia occurred after the operation of hematoma or aneurysm of left hemisphere, “nonaphasic” misnaming associated with disorientation, denial of illness and mood changes was observed. Brain CT scan revealed lesions in medial occipital, inferior temporal or anterior frontal lobe, basal ganglia or thlamus of dominant hemisphere. Based on the analysis of misnaming and the location of lesions, “nonaphasic” misnaming seems to be classified into Group 1., cases with irrelevant paraphasia and irrelevant utterance (case 1,2), Group 2., cases with monemic paraphasia and irrelevant utterance (case 3,4), Group 3., cases with predominantly irrelevant paraphasia (case 5), and Group 4., cases with nonaphasic misnaming caused by the lesion of right hemisphere.
The grammatical errors observed in three conduction aphasics were reported. These errors were the substitution of a "Joshi (postpositional particle in Japanese grammar)for another “Joshi” . The patient usually tried spontaneously to correct the error himself and this behaviour seemed to be very similar to the spontaneous self-correction(conduite d'approche)of phonemic paraphasias which is regarded as a characteristic of conduction aphasia. It was argued that these grammatical errors should be considered a kind of paraphasia rather than paragrammatism in the proper sense of the word. We proposed accordingly that they could be called “paragrammatistic paraphasias”.
The incidence and nature of verbal perseveration occuring after cerebrovascular disease were investigated. Out of 59 cases, verbal perseveration was found in 21 of 23 aphasic patients. The perseverative errors were classified into two types;clonic and intentional perseveration. Furthermore, intentional perseveration was divided into two types;immediate and delayed type according to temporal relation of a response to the original stimulus. Clonic perseveration was found in 5 cases;one in naming and repetition tasks, 5 in series tasks. Intentional perseveration was found in 19 cases ; 17 in naming, 10 in repetition, and 19 in series teasks. There was no correlation between the duration of cerebrovascular disease and perseveration. On CT findings the lesions of frontal lobe, temporal lobe, parietal lobe, thalamus, and basal ganglia were detected. And there were tendencies that the larger the lesion was, the more frequent verbal perseveration was. The hypotheses of mechanism for producing perseveration were reviewed and verbal perseveration was supposed to be related with the disinhibition of memory trace.
It has been observed since long that the cases of cerebellar hemorrhage often had the difficulty of rehabilitation not only by a truncal ataxia but also by a retarded intelligence, a loss of volition and a decreased attention span. The authors investigated 7 cases of operated cerebellar hemorrhage of moderate size on how they were disturbed on the higher cerebral functions by applying them WAIS and other several neuropsychological test batteries. The frontal lobe functions were examined by the original test batteries of our design. As the results, there was the moderate or severe decrease of WAIS on all 7 cases and also marked disturbance of the frontal lobe functions on 4 cases excluding 3 unapplicable cases. The above results will suggest anyhow that the cerebellar damage around the dentate nucleus would give rise the disturbance of generalized higher cerebral functions, though its mechanism has not not been elucidated. It would be very important for us now on to examine extensive higher cerebral function on those cases of cerebellar hemorrhage.
A 41-year-old right-handed male, showing anterior callosal disconnexion symptomes after infarction of the corpus callosum identified by MRI, was studied to elucidate whether each cerebral hemisphere would be specialized even in elementary auditory perception such as hearing pure tone. The patient was examined for Bekesy audiometry, loudness discrimination and simple reaction time not only with his preferable right hand but also with his left hand. The most noticeable finding in those tests was that the left and right hand produced decisively different results even though the same ear was stimulated. Bekesy audiometry showed that the thresholds with the right hand were initially higher than the left, but in the subsequent tracings, they conversely kept lower level. This was more remarkable on the contralateral left ear. The tracings with the right hand were far larger in width than the left, and were sometimes suspected to overrun the real hearing limit. Loudness discrimination test demonstrated the ascending limens of the right hand were lower than the left, however the descending limens of the right hand often reached zero dB increment as if the patient could perceive the change of loudness that had already disappeared. Auditory and visual simple reaction time of the left hand was shorter than that of the right hand, although the difference was too small to account for the above-described findings. These results demonstrate that the right and left hemispheres are probably differentiated even in the most elementary auditory perception. The left hemisphere would be less sensitive to the onset of sound, but more active to pursue the sound that had been once perceived, which tends to enlarge perception according to an inner auditory image. The right hemisphere, in contrast, seems to be more passive and naive in receiving the onset and the end of sound.
A simple test was designed to detect the disorder of vigilance, and its efficiency in clinical use was examined. The subject was instructed to tap a table continuously at the rate of once per second with a pencil held in his normal hand. The examiner, relying on a stopwatch, counted the number of tapping sounds per block of ten seconds for a duration of five minutes. As the index of this task, the mean and SD values of tapping sound numbers for thirty blocks (i. e., five minutes) were used. It was expected that performance of the task would fluctuate if vigilance was disturbed. For clinical examination, this task was applied to patients having left unilateral spatial neglect (left USN), who tend toward distraction and poor concentration in their daily life. In contrast to the control group, many patients in the left USN group showed a high mean and a large SD value. These results show that this task reflected the behavioral features of the left USN patient stated above. They also suggest that left USN patients cannot adequately control their own behavior continuously (i. e., sustained attention or vigilance disorder).
A case is reported of a 60' year- old right-handed man in whom syndrome of semantic aphasia developed 5 months after the onset of a left thalamic hemorrhage preceded by a right thalamic hemorrhage which has occured about 21 months before. He was admitted to Kuwana Hospital because of vomiting and left hemiparesis on April 23, 1983. CT scanning disclosed a hematoma measuring about 11 ml which occupied the postero-lateral portion of the right thalamus rupturing into the trigon of the lateral ventricle. Left spatial agnosia, construetional disturbance and left homonymous hemianopia were found. He showed improvement and was discharged about 1 month after the admission. On July 18, 1985, he was admitted again because of the occurrence of a hematoma measuring about 4 ml which involved the postero-lateral portion of the left thalamus extending medially and upwards. Examinations revealed transcortical sensory aphasia as well as left spatial agnosia and constructional disturbance which had been found during the first admission. About 5 months after the admission, the transcortical sensory aphasia disappeared and a syndrome of semantic aphasia developed associated with simultaneus agnosia. Four months later, the syndrome of semantic aphasia improved greatly and the other syndrome showed some improvement. Our case with semantic aphasia had all the components of typical semantic aphasia described by Ohashi et al and was similar to cases with semantic aphasia caused by cortical lesion reported by Hier. This semantic aphasia lasted for a relatively long period was considered to be due to the bilateral thalamic lesions.
In order to investigate agrammatism in right-handed crossed aphasics (RCAs), the speech characteristcs of 4 RCAs were compared with those of 3 left-handed crossed aphasics (LCAs) and 8 Broca's aphasics. The two crossed aphasic groups (RCA and LCA) involved both fluent and non-fluent types. It was believed that agrammatism could be attributed neither to articulation difficulties nor to prosodic disorders. While the agrammatic patients displayed good abilities in manipulating vocabulary representing semantics, they had poor syntactic knowledge. In speech production, they produced the sequences of content words without functional words more often rather than make errors in syntactic manipulations. The characteristics of agrammatism in RCAs and LCAs were mutually similar, As a result, the dissociation between vocabulary and syntactic knowledge observed in these cases might be attributed to the abnormal lateralization of language functions.