Executive functioning deficits due to prefrontal damage cause disorders of planning, strategy application, self-regulation, inhibition, goal-directed behavior, initiation, and insight. One of the theoretically based interventions is metacognitive strategy training, that is, self-monitoring and self-regulation training. The problem solving training is supported by Cicerone’s systematic reviews as practice guideline. The Goal management training is another promising method based on numerous cognitive rehabilitation findings for sustained attention and executive function.

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I have given an outline regarding cognitive impairment implicated in the damage to the frontal lobe and to the basal ganglia. Damage of the frontal lobe causes various impairments. Among them those which are well established as a definite symptoms and known its causative lesions are clumsiness, anarthria as central gyrus symptoms, impairment of central executive of working memory, set shifting, agraphia, dystypia, word retrieval difficulty, anterior operculum syndrome as dorsolateral symptoms, and grasping reflex, instinctive grasping reaction, releasing phenomena of well learned praxes as medial frontal symptoms. Damage to the basal ganglia shows similar symptoms as found in the case of frontal lobe damage, however, there are some differences ; basal ganglia damage does not develop impairment of set shifting but shows impairment of maintaining newly acquired set, and also manifests visuo-spatial impairment when simultaneously activating central executive function.

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In recent years, the mechanism of voluntary movement has been clarified by neurological studies in monkeys. Planning neurons, programing neurons, and mirror neurons have been identified, and brain imaging studies have shown that these neurons are also present in humans. It is these neurons that may be affected in ideation apraxia (IA) . Here, we examine rehabilitation methods that may be effective in IA patients. We investigated aphasic patients' apraxia using a non-verbal method. In aphasic patients with IA, perception and cognition were preserved. Aphasic patients with IA showed low ADL scores at admission and discharge from the hospital, but apraxic patients improved their ADL score by rehabilitation. We evaluated the effect of intensive cooking training on right hemiplegic and aphasic patients with IA. The cooking abilities of the patients improved significantly after the intensive cooking training. However, we have not established methods of efficient training for IA patients. IA is thought to result from lesions to the pathway leading to establishment of the motor program at the frontal lobe. We propose that the rehabilitation of IA patients should include tool training without mistakes and repetitive use in an appropriate environment.

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Frontal lobe related disorders could be categorized as disturbance of executive-control system and of motivational salient system. The latter should be considered as social behavioral disturbance.1) Disinhibition,2) Apathy,3) Stimulus-bound stereotypical behavior and 4) Loss of awareness or reduced awareness about these impairments are regarded as motivational salience impairments. The author has considered the relationship between these disorders and motivational salience impairments.

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The CT and MRI findings of the patients with frontal lobe infarction were discussed. In this paper, aphasia was chosen as the left frontal lobe sign. The patient with motor aphasia showed the infarction of the lesion including both the Broca's area and the precentral gyrus. Pure word dumbness occurred in the infarction of the precentral gyrus. The patients who have a lesion of the Broca's area presented transcortical sensory aphasia. Transcortical motor aphasia was observed next to the lesions surrounding Broca's area which was produced by the borderzone infarction, or medial portion of the frontal lobe which was perfused by the anterior cerebral artery. Superficial borderzone infarctions may cause transcortical aphasia. Anterior type borderzone infarct will produce transcortical motor aphasia. Deep borderzone infarct due to carotid or middle cerebral occlusion of its main trunk may also produce transcortical motor aphasia. The marked reduction of cerebral blood flow in the frontal lobe including the Broca's area and the precentral gyrus will be observed in these cases with borderzone infarctions when measuring the cerebral blood flow using SPECT or PET.

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In this review, I explained the functional anatomy and neuropsychological assessments of frontal lobe, representing some cases with frontal dysfunction. Frontal lobe could be separated into following three portions : convex, orbitofrontal, and medial. The damage of each portion revealed the characteristic symptoms, that is dysexecutive syndrome, disinhibition, and akinetic mutismn, respectively. Neuropsychological tests of frontal function contain Stroop test, word fluency, Trail-Making Test (TMT) , Wisconsin Card Sorting Test (WCST) , and Frontal Assessment Battery (FAB) . Brain regions activated by these tests were investigated through the activation studies using functional MRI and positron emission tomography (PET) . Nowadays, the FAB is frequently used in the clinical situation, but we should notice that the low score of the FAB does not always mean frontal lobe dysfunction.

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We evaluated frontal lobe functions using functional magnetic resonance imaging in patients with diffuse axonal injury. The findings demonstrated increase of activity (1) in bilateral dorsolateral prefrontal regions during the auditory serial addition test, (2) in bilateral posterior parietal regions during the effortful learning task, and (3) dorsomedial prefrontal regions during the self- knowledge task. These findings may mean compensatory activity of cortex during recovery stage after diffuse axonal injury. Since correlation between cortical activities and performance is not consistent, we must be careful to interpret meaning of cortical activities especially during the recovery stage.

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   Aphasia is a common consequence of stroke that typically results from injury to the extended network of cortical and subcortical structures perfused by the middle cerebral artery in the left hemisphere. Although most patients shows some degree of spontaneous recovery, usually notably during the first 3months following stroke onset, the majority of patients are left with some degree of chronic deficits for which current various rehabilitative treatments are marginally effective. The understanding of the mechanism of post-stroke aphasia recovery is essentially important for developing the effective therapy to promote the improvement. The recruitment of lesioned and perilesional regions in the left damaged hemisphere is most important for aphasia recovery, for which the role of non-dominant right hemisphere is controversial. Overactivity of the right hemisphere due to transcallosal disinhibition following stroke gives beneficial effect in some cases, but in others shows maladaptive and detrimental effect to aphasia recovery.
   Recently, non-invasive brain stimulation such as repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS) is applied to post-stroke aphasia rehabilitation as supplementary therapy. In this paper, the author reviewed the efficacy of low-frequency rTMS over the Broca's area (BA45) homologue of unaffected right hemisphere for post-stroke aphasia.

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In conjunction with studies concerning time-course analysis of language functions in aphasics, we investigated long-term follow-up data for lesions of 270 right-handed aphasics with left lateral damage. We also studied 37 aphasics whose language functions declined in the general scores on the SLTA, examining functional change in the various factors affecting those scores. The results were as follows. Depending on the lesion site and age at onset, recovery of aphasia symptoms varies in course greatly ; however, many aphasic cases show recovery over long terms of at least six months or more. In terms of general score on the SLTA, comprehensive ability and ability of phonological retrieval from a kanji/kana word—functions of language information processing that are simpler than other functions—are easily restored. Comprehensive ability and ability of phonological retrieval from a kanji/kana word are functions that are easily maintained after speech therapy. Functions that require more complicated language processing, such as syntactic processing and writing ability, easily decline. Functional restoration of language by therapy is not stable but rather fragile. Language symptoms, in which maintenance is needed, require continuation of long-term speech therapy. Based on these results, we reconsidered the chronicity of aphasia.

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To assess attention functions in patients with Machado-Joseph disease (MJD) , we tested 15 genetically confirmed MJD patients, and 15 control subjects matched for age, education, and global cognitive status. We administered the Frontal assessment battery (FAB) , category and letter fluency, digit forward and backward span, visual memory forward and backward span, Kana pick-out test, and Trail Making Test (TMT) . The MJD patients showed significantly lower scores in the letter fluency, digit backward span, and Kana pick-out test. The results of the tests concerning frontal function suggest that the deficits of the divided attention in the MJD patients. On the other hand, the deficits were not observed in the tasks of category fluency, “Similarities, Motor series, Confliction instruction, Go-NoGo, Prehension behavior” in the FAB, digit forward span, visual memory span, and TMT-A, B, B/A. We speculate that the MJD patients have the dysfunction not of the alternating attention but of the divided attention involving the multiple processing. The dysfunction in MJD patients is considered to be due to cerebello-cortical circuit damage occurring in MJD.

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Objective : To examine the nature of false recall in a common word-list recall task and its relation to other cognitive deficits in patients with Alzheimer's disease (AD) . Subjects : We studied 77 AD patients who underwent the Mini-Mental State Examination (MMSE) and the Alzheimer's Disease Assessment Scale (ADAS) . The mean age of the patients was 80.1 ± 6.4 years and the mean MMSE score was 18.7 ± 4.6. Methods : We collected falsely recalled words from the responses of each patient in the Word Recall subtest of ADAS, and examined the relation between the falsely recalled words and the target words. We also conducted analyses of logistic regression to assess the effect of the scores of other cognitive tests on the presence or absence of false recall. Results : Twenty-four of the 77 patients showed false recall. The mean number of falsely recalled words in all patients was 1.1 ± 2.6. Among a total of 19 falsely recalled words,13 words (68%) belonged to one of the four semantic categories of the target words. We obtained a significant odds ratio for scores on the Word Recognition subtest of ADAS (p < .05) , that is, patients with better scores on the Word Recognition subtest were more likely to show false recall in the word recall task. Conclusion : AD patients with impaired memory encoding may show worse scores on word recognition tasks. We consider that patients of this type fail to encode semantically related words which are activated during the presentation of the targets in the word recall task, and are less likely to show false recall. These results suggest that the mechanism of false recall in AD patients on the Word Recall subtest of ADAS is similar to that of healthy subjects.

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We reported a patient who showed paralexia during a reading task involving a list of kanji words. She produced the target form of the kanji which came previous in the list. The patient was an 82-year-old, right-handed woman who was admitted to a hospital following a cerebral infarction. The location of the infarction was in the left frontal lobe and the insula. She showed the symptoms of mixed transcortical aphasia. She presented with verbal paraphasia and neologistic errors when asked a kanji word, but she produced the correct response, delayed, when she read the next kanji in the list. This phenomenon occurred four times while reading the kanji list. These paralexic errors had no phonemic or semantic similarities to the target form of the next kanji. These responses could be interpreted as a different type of semantic perseveration.

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We investigated the efficacy of two types of learning methods for Kanji writing in 14 Japanese children with developmental dyslexia.12 were third to sixth graders in Japanese primary schools, and the other two were seventh or eighth graders in Japanese junior high schools. One method was similar to that traditionally taught in schools (visual method) , and the other consisted of memorizing the construction of Kanji characters orally (auditory method) . Although the participants had average intelligence, language ability, and ability in auditory memory, they had disorders of phonological awareness and/or visual cognition including visual perception and memory. All participants improved in learning Kanji writing through the auditory method, and in 12 of the 14 participants this method was more effective than the visual method. These 12 participants had disorders of visual cognition and/or visual memory. Results were not significantly different between the two methods for the two participants who did not have disorders of visual cognitive processing. Results suggest the benefit of applying the auditory method to learning Kanji characters in Japanese children with developmental dyslexia.

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   We developed a virtual reality (VR) test to evaluate the cognitive function of brain-damaged patients in a shopping task with the use of a virtual reality system. The aim of this study was to test if the VR test is applicable to patients with brain damage and to find out its significance by comparing the test performance with the results of other neuropsychological tests. The participants were asked to buy four items in the virtual shopping mall quickly in a rational way. The score for evaluation included the number of items bought correctly, the times to refer to the purchase list, the times to check the items bought in the bag, the numbers of movements between shops, and the total time spent to complete the whole shopping.
   The participants were 10 patients with some forms of brain damage (five with cerebrovascular disease and five with traumatic brain injury) and 10 healthy control subjects. The cognitive function of the patients was evaluated using Mini-Mental State Examination (MMSE) , star cancellation and letter cancellation test, Symbol Digit Modalities Test (SDMT) , Simple Reaction Time Task (SRT) of Continuous Performance Test, Rivermead Behavioural Memory Test (RBMT) , Zoo Map Test, Everyday Memory Checklist (EMC) , and Dysexecutive Questionnaire, while that of the controls was screened using MMSE.
   The brain-damaged patients were able to complete the shopping task after a short practice session. However, the mean number of times referring to the list and the mean number of movements were significantly greater for the patients, and the mean total time was significantly longer for the patients than for the normal controls. These scores of the VR test correlated with the scores of MMSE, SDMT, SRT, RBMT, and EMC. The results suggest that the VR test may be able to evaluate the ability of prospective memory and attention in patients with brain damage.

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We developed a new brief psychological assessment scale (Psychological Assessment Scale by Facial Expression for Demented People-Interview version : PAFED-I) for patients with severe dementia comparable to Functional Assessment Staging (FAST) stage 6 and 7. Moreover, we examined the reliability and validity of PAFED-I. PAFED-I consists of 18 items associated with changes in the patients' eyes (eye score) and 12 items associated with changes in their facial expressions (expression score) . The testers individually interviewed patients with severe dementia and evaluated each item. In the case of patients with FAST stage 6, the eye and expression scores showed sufficient internal consistency and inter-rater reliability. In addition, these scores significantly correlated to the Clinical Assessment for Spontaneity (CAS) score. In the case of patients with FAST stage 7, the eye score showed sufficient reliability and significantly correlated to the CAS score. We concluded that PAFED-I was useful for evaluating the spontaneity in severe dementia.

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   Visual hallucinations as a defect of visual field caused by organic lesions are often seen when the eyes are opened. We report two cases of visual hallucinations, without visual field defect, who experienced hallucinations only when their eyes were closed.
   Case 1 : A 64-year-old female had a 5-year history of diplopia during a specific head position．After excision of a right temporo-parietal convexity meningioma, she experienced several types of formed visual hallucinations only when her eyes were closed. These images lasted for 3 days. The diplopia disappeared after surgery. Magnetic resonance images showed no brain damage. A SPECT study one month after the surgery showed hypoperfusion of the tumor bed.
   Case 2 : A 66-year-old woman underwent craniotomy surgery for asymptomatic parietal parasagittal meningioma. After the operation, she saw numerous greenish objects like the letter ‘L’, the edges of which blinked on and off. These objects disappeared on the 4^th day after the surgery. Magnetic resonance images revealed no brain damage.¹²³I-IMP SPECT on the 9^th day after the surgery showed hyperperfusion of the bilateral cuneus.
   Both cases were alert and had no visual field disturbance and no delirium. Neither did they experienced any seizures.
   Some articles suggest that local alteration of cerebral blood flow in the visual area of brain by stroke, trauma, or seizure may be associated with the generation of visual hallucinations. Luxury perfusion in the visual brain area caused by tumor excision also may be associated with generation of visual hallucinations. In patients who have visual hallucinations without visual field defect, the interruption of visual stimulation by closing the eyes may be the cause of the phenomenon.

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We report a case of a 65-year-old right-handed man who developed a left posterior cerebral artery infarct and subsequently developed associative visual agnosia that evolved to optic aphasia. MRI revealed lesions around the interior of the left lateral occipital lobe, the splenium of the corpus callosum, and the thalamus. Approximately 2.5 months after the onset, the patient's visual naming ability was severely impaired, although tactile naming, auditory naming, and naming of objects in response to verbal descriptions were preserved. He could copy geometric figures and distinguish matching forms from differing forms. However, he could not categorize visually presented pictures. These results suggested that his visual form perception was preserved and that his visual agnosia involved associative disturbance in processing visual form perception to semantic memory. Approximately 3.5 months after the onset, he could gradually determine with certainty whether he had ever seen the stimulus presented, that is, his subjective familiarity recovered. He could simultaneously point to and describe pictures named by the examiner. Approximately 4.5 months after the onset, he could categorize visually presented pictures that he could not name. The disturbance in visual recognition gradually improved, with visual agnosia evolving to optic aphasia. The improvement observed in this patient appeared to be affected by the semantic potential of his right hemisphere, which was in compliance with De Renzi's hypothesis. Although the patient could categorize visually presented pictures and the disturbance in visual recognition improved to some extent, the deep test results showed that the visual recognition in the right hemisphere was more incomplete and less developed than the verbal recognition in the left hemisphere. Optic aphasia leads to difficulties in visual naming although it is possible to visually recognize pictures, ; therefore, we thought that the recognition in the right hemisphere was too incomplete to name the visually presented pictures.

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