We evaluated changes in cognitive functions after carotid endoarterectomy(CEA) in patients with significant carotid stenosis who did not have aphasia, apraxia or agnosia. We prospectively conducted evaluations before and 7 days after surgery. Although there were no significant differences in MMSE scores, MoCA scores was significantly improved after CEA(P=0.032) , especially in those who had left carotid stenosis. Furthermore, visuospatial/executive(P = 0.014) and delayed recall(P=0.041) were significantly recovered in patients with left carotid stenosis. MoCA might detect slight changes in the cognitive functions of patients with carotid stenosis who undergo CEA. CEA may improve cognitive functions in patients with carotid stenosis, especially when stenosis is on the left side.

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The purpose of this study was to examine the neural processes involved in the improvement of pure alexia. The patient was a 35-year-old right-handed woman with a junior college education, who showed pure alexia following excision of an arteriovenous malformation in the left occipital lobe. Auditory comprehension, spontaneous speech, and spontaneous writing of Kana were, however, all preserved. MRI revealed lesions around the medial side of the lateral occipital lobe in the left hemisphere, including the lingualis gyrus, the fusiform gyrus, and the splenium of the corpus callosum. A reading test was conducted twice, at 6 and 15 months after admission. The results of the first test showed that the stroke count effect was confirmed with response rate, suggesting the effects of kinesthetic memory associated with kinesthetic facilitation reading. The results of the second test showed that imageability influenced semantic processing, indicating the effects of semantics. These findings suggest that there might be two types of processes involved in the improvement of pure alexia:the compensatory kinesthetic facilitate route mediated by motor imagery for letters；and the activated semantics route mediated by imageability.

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  A functional magnetic resonance imaging (fMRI) method, which can be used to perform a covert speech word generation task, has been used to identify the language dominant hemisphere. However, in the covert speech method, the performance of a subject during the task can'-not be assessed. Moreover, the activation of the premotor area may affect the calculation of laterality index (LI) . We performed a new fMRI method that uses a word generation aloud task as a stimulus and nonword reading aloud task as a control to offset the activation of the motor cortex. Thereafter, we examined whether LI can be calculated by this method.
  fMRI data were acquired using a 1.5T Philips Gyroscan Intera system. Eleven healthy, right-handed volunteers participated in this study. The fMRI task paradigm involved four 30-s blocks of tasks alternating with blocks of controls. We created activation maps by using SPM8. The threshold of the activation map was set at P＝0.001 (uncorrected) . We calculated LI from the activated voxels in the region of interest set at the inferior frontal gyrus and precentral gyrus, and compared the results with that of the conventional covert speech method.
  The left premotor area, supplementary motor area, and Broca's area were activated in the covert speech method. The observed activation of the supplementary motor area and Broca's area was the same as that observed in the covert speech method, ; however, the activation of the premotor and primary motor areas was not observed in the nonword reading aloud method. In addition, there was no significant difference in the calculated LI between the covert speech method and nonword reading aloud method. Because the subject's performance during tasks can be assessed by this method, it can be used for identifying the language dominant hemisphere with higher reliability.

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  We investigated the influence of semantically relevant information on comprehension deficit in 35 aphasic patients and 10 healthy controls. We developed new auditory word-picture matching tasks which were controlled by semantically relevant information between the target word and distracters, and evaluated the subjects in performing these tasks. The semantic relevance of the distracters consisted of "situational" relevance and "category" relevance with the target word. For example, the target word "dog" included situational (home) and category (mammal) information. For each task, six pictures (one target and five distracters) were presented to the subjects. One of the distracters had both situational and category associations with the target word (e.g., cat) , two others had either a situational or category association with the target word (e.g., home or elephant) , and the others had no relevance with the target word (e.g., eraser, etc) .
  The number of correct responses in the aphasic group was significantly lower than that in the control group. The mild aphasic subgroup showed errors mostly related to the target word, and there were few errors involving "non-relevant" items. The severe aphasic sub group showed more non-related errors than the mild aphasic sub group.
  These results suggest that situation and category are semantically relevant information that influence auditory word-comprehension deficit in aphasics.

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We administered three verbal fluency tasks to both young and elderly people, and examined the effects of word class and aging. The subjects were 35 healthy young (18-23 years) and 35 healthy elderly (65-79 years) persons. Each participant was instructed to generate as many different words as possible in the following categories over a 60-second period: (1) common nouns ('animals' and 'vegetables') , (2) proper nouns ('company names' and 'famous people's names') , (3) verbs (things people do) . The elderly group generated significantly fewer correct responses and significantly more incorrect responses as compared to the younger group. All of the subjects generated significantly fewer correct responses in the verb category than in the common noun categories. In addition, in the verb category alone, there was a significant decrease in the number of correct responses and significant increase in the number of incorrect responses with aging. We concluded that the reduced verb fluency responses in the elderly group reflects diminished executive function with aging.

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