From the view point of diagnostic imaging, the pathological process of brain tissue can be classified into functional and morphological changes. Morphological changes may occur when the brain tissue became necrotic due to brain ischemia or degeneration, whereas functional changes can be defined as the brain tissue functionally impaired but not yet morphologically injured. In the early stage of pathological process, the functional changes which can be captured as hypoperfusion and/or hypometabolism appear in prior to the morphological changes, but the morphological changes gradually became conspicuous and both functional and morphological changes may converge in the later stage. Computerized tomography (CT) and magnetic resonance imaging (MRI) are basically used in the detection of the morphological changes, while positron emission tomography (PET) and single photon emission computerized tomography (SPECT) are applied to the evaluation of the degree and distribution of the functional changes. When the intracranial lesion is suspected, CT is definitely the first choice imaging device for screening. The hypodense areas shown on CT images designate the already necrotic morphological changes, and the functional changes usually exist more extensively. Therefore, the hypodense lesions on CT do not comprise the whole extent of the pathological process. Since there is no radiation exposure and the sagittal and coronal planes are easily available with a higher resolution of soft tissue, MRI is thought to be superior to CT. Diffusion weighted imaging (DWI) is nowadays indispensable in the management of acute stroke, because it shows ischemic lesions very early after the onset of stroke symptoms. Diffusion tensor imaging (DTI) is a non-invasive technique capable of delineating white matter pathways in vivo and quantifying microstructural changes. Functional MRI detects the blood oxygen level-dependent (BOLD) changes in the MRI signal that arise when changes in neuronal activity occur following a change in brain state, and is now widely applied to the brain activation studies.

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As a noninvasive neuroimaging method to reveal the higher brain functions, here we introduce a newly developed integrative fMRI-MEG method combined with a spatial filtering (beamforming) technique. A possible difficulty in integrative fMRI-MEG analyses is mismatches between activated regions detected by fMRI and MEG. These mismatches may decrease estimation accuracy, especially in the case that there are strong temporal correlations among activities in fMRI-invisible and-visible regions. To overcome the difficulty, we devised a spatial filter based on a generalized least square estimation method. The filter can achieve the accurate reconstruction of MEG source activities even in the case that a priori information obtained by fMRI is insufficient. In addition, we describe feasibility of a newly developed optically pumped atomic magnetometer as a magnetic sensor to measure MEG and MR signals simultaneously. The applicability of new neuroimaging methods and sensors as described in the present paper would provide important advancements in cognitive brain research, and improve clinical diagnosis and management of neurological and psychiatric disorders.

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I described the principle and applications of single photon emission computed tomography (SPECT) and positron emission tomography (PET). SPECT can show the cerebral blood flow (CBF), and, because of its running cost, it is widely used in many hospitals. SPECT is useful to interpret the neuropsychological symptoms and diagnose the patient with dementia. PET can measure the CBF and various metabolic factors in the brain, and is mainly used for the basic research of cognitive neuroscience and neurological diseases. PET activation study can reveal the brain regions which participate in some cognitive processing. By the PET, we can know the behavior of some neurotransimitters in patients' brain. Nowadays, statistical image analysis is frequently utilized for the diagnosis of Alzheimer's disease. It can clearly and easily visualize the brain regions with abnormal function, but, the other side, we can easily make a mistake of false positive or false negative, if we rely on its findings too much. In order to correctly use the findings of SPECT and PET, the importance of close examination of patients can not be overemphasized.

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Images of fiber bundles in cerebral white matter can be constructed by fiber tracking (tractography) using diffusion tensor imaging. This method has enabled visualization and clinical assessment of neuronal fibers. In this study, we evaluated the use of tractography of the arcuate fasciculus in patients with left middle cerebral artery infarction. We performed fiber tracking of the arcuate fasciculus in patients with brain infarction in the acute stage, and calculated the number of fibers and fractional anisotropy (FA) values. Though the left/right ratio of FA did not correlate with the prognosis of aphasia, the ratio of the number of fibers correlated with the prognosis of aphasia. Therefore, the left/right ratio of the number of fibers might aid in predicting the prognosis of aphasia. Saur et al. conducted a tractography study combined with functional magnetic resonance imaging (fMRI). They identified points that were activated in association with verbal tasks by using fMRI and performed fiber tracking along these activated points. The results showed that the verbal dorsal stream is associated with repetition and the verbal ventral stream is associated with verbal comprehension.

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Dysphagia is known to be a common complication of cerebral ischemic disease. Nearly 20∼50% of patients of stroke are initially found to present dysphagia, but in most of them the symptom will resolve by the end of the first week. On the other hand, a few cases complicate aspiration pneumonia and require tube feedings. Although assessment of swallowing function transitionally with the barium swallowing test is useful for management of dysphagia, estimation from lesion site has an important meaning, too. In this review, we will describe the functional anatomy of swallowing system and the correlation between lesion sites and dysphagia.

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Central mechanisms of articulation and deglutition are compared and discussed. Rolando area, midbrain, dorsal olive represent crucial areas for the production of vocalization. In a recent study, a discrete area in the ventrolateral pontine brainstem may play a role in vocal pattern generation of frequency-modulated vocalizations.

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   The case was a 69 year-old right-handed female who suffered from fluent aphasia following left temporoparietal infarction. She made no errors in word repetition and word reading tasks : only in oral naming tasks, she produced various paraphasias and neologisms with verbal self-correction, commonly referred as “conduites d'approche”.
   We classified her oral naming task errors into six categories (mixed, formal, phonological, semantic, or irrelevant pharaphasias, or neologisms) using three indexes as follows : 1) lexicality, 2) semantic relevancy, and 3) phonological relevancy. For the sake of objectivity, “index of phonemic similarity” was applied to judge phonological relevancy.
   It is notable that she produced a significant amount of non-word errors (phonological paraphasias and neologisms) in which syllabic and prosodic structures of the target words were preserved even if segments were pronounced incorrectly. She also made some non-word errors in which elements of different words were combined into one. Furthermore, she produced real-word errors phonologically related to targets (formal paraphasias and mixed paraphasias).
   We suspected that she had difficulty retrieving the phonological form of an item. Specifically, she may have had a deficit to spell out segmental information while preserving functions to spell out syllabic and prosodic structure. Various non-word errors which occurred in oral naming tasks may have resulted from a struggle to fill out a “frame” composed of syllabic and prosodic structure with appropriate segments. Occurrences of real-word errors phonologically related to targets and non-word errors produced by combining elements of different words into one indicate that the semantic and phonological level of a word may interact with one another for retrieval of the word.

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   We evaluated three patients of progressive non-fluent aphasia. A degenerative disease undiagnosed clinically in case 1, Alzheimer disease (AD) in case 2 and corticobasal degeneration (CBD) in case 3 were suggested. We investigated three patients focusing on common characteristics of linguistic symptoms on Standard Language Test of Aphasia (SLTA) and brain imaging (head MRI and SPECT) to identify the characteristics correlated with these neurodegenerative diseases.
   The common linguistic symptoms in these three patients were non-fluent speech with the scores for picture naming and comprehension of letters being remarkably better than other items on SLTA. These findings might be one of characteristics associated with the degenerative process of the frontal and temporal lobes before that of posterior cerebral areas. In addition, case 3 demonstrated agraphia in the early stages of illness, differing from cases 1 and 2. Progressive non-fluent aphasia in the early stage might be devided to two types. One is characterized by remarkable non-fluent speech without apparent agraphia and the other non-fluent speech with agraphia.

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   The purpose of this study was to investigate if neuropsychological assessment scores can predict employment outcome in patients with brain injury (18 to 64 years of age, excluding students). We conducted Wechsler Adult Intelligence Scale-Revised (WAIS-R), Rivermead Behavioural Memory Test (RBMT), and Trail Making Test-A and B (TMT-A, TMT -B) to 113 patients to assess their cognitive deficit levels. We also divided patients into employed and unemployed groups.
   When discriminant analysis was applied to the results, it was found that the RBMT scores had the greatest impact on the standardized canonical discriminant function coefficients in variables. Furthermore, the scores for picture arrangement and similarity, a subtest of WAIS-R, and TMT-B scores had relatively high impact. This analysis was able to correctly classify 72.9% of the subjects.
   We concluded that neuropsychological assessments are useful to predict employment outcome in patients with brain injury.

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In this report, we describe a 35-year-old right-handed man with MELAS who was followed up for 14 months, focusing on his dysgraphia. MRI performed at the initial examination revealed extensive lesions in the left parietal, temporal, and occipital lobes, and in a subsequent examination after recurrence of a stroke-like episode, similar lesions were found in the corresponding areas of the right hemisphere. After the first stroke-like episode, the patient presented with amnestic aphasia, agraphia for Kanji, and an inability to recall visual images. About 6 months later, he had another episode resulting in worsening of dysgraphia and new symptoms of left hemispatial neglect, visual agnosia with various visuospatial deficits, dyspraxia, and constructional disability. He was unable to even copy a Kanji character. When writing Kana letters, he made unusual errors such as rotation or omission of the strokes of the letters and left some strokes uncrossed when they should be crossed. He also had difficulty in copying figures. It was revealed that he was able to draw a line from one point to another and trace letters, i. e., his ability to draw strokes of letters was preserved. However, when observing a dot or line presented on a stimulus sheets, he failed to reproduce its location on a blank sheet of paper. In another experiment, he had difficulty in judging whether or not two successively displayed dots appeared at the same location. It is suggested that these disturbances after the second episode are associated with disability to focus on multiple objects simultaneously, disturbance of visual perception of object orientation, and deficit of internal visuospatial coordinates.

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To investigate whether prospective memory (PM) impairment is related to dementia or not, and what the PM impairment process is, we examined cognitive functions using the “message task in delayed recall” in the Rivermead Behavioural Memory Test Japanese and other neuropsychological tests. A total of 56 elderly subjects (25 Alzheimer's disease : AD,18 mild cognitive impairment : MCI,13 control subjects : CS, average 77.1 year-old) were studied. AD subjects were highly impaired in both “remembering to remember” and “remembering content” in PM, and they showed lower performance in memory, frontal lobes functions and visual process, which corresponded to deficits of process in “encoding the intention”, “retention”, “recognition of PM cue” and “retrieval from the cue. ” MCI subjects were also impaired in “remembering to remember” and “remembering content”, and showed lower performances in memory and frontal lobes functions, which corresponded to deficits of process in “encoding”, “recognition” and “retrieval”. Even CS subjects were impaired in “remembering to remember”, and showed lower performance in frontal lobes function, which corresponded to deficit of process in “recognition”. We suggest the impairment processes in the groups differ, and that AD subjects are impaired all the PM processes.

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We report a case of Wernicke's aphasia with neologistic jargon after subcortical hemorrhage involving the left supramarginal gyrus, superior and middle temporal gyri, and angular gyrus. Neologisms phonologically irrelevant to the target words were frequent at the early stage, but gradually changed into phonological fragments of the target words or phonemic paraphasia (substitutions and displacement) and finally evolved into conduction aphasia. During the course of recovery, the patient showed no verbal paraphasia or circumlocution, which suggested that there was no impairment at the lexical level. Though the mechanisms underlying neologism are still controversial, we speculate from the clinical course of our patient that disruption of phonological selection may play a role in its occurrence. This type of neologism can presumably be categorized as “post-lexical” neologism.

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