Japanese Journal of Cognitive Neuroscience
Online ISSN : 1884-510X
Print ISSN : 1344-4298
ISSN-L : 1344-4298
Volume 13, Issue 2
Displaying 1-26 of 26 articles from this issue
  • Marsel Mesulam
    2011 Volume 13 Issue 2 Pages 153
    Published: 2011
    Released on J-STAGE: April 12, 2017
    JOURNAL FREE ACCESS
    Dementias can be classified as amnestic, comportmental or aphasic, according to the nature of the major impairment. Alzheimer’s disease typically leads to an amnestic dementia where memory loss is the major cause of impaired daily living activities. This is consistent with the hippocampal/entorhinal location of the initial neurodegeneration. The frontotemporal Lobar Degenerations(FTLD)constitute the second major class of dementias. The neuropathology is characterized by focal neuronal loss, gliosis, tau inclusions, or TDP-43 inclusions. FTLD can lead to pure cognitive changes as in primary progressive aphasia(PPA)and the behavioral variant of frontotemporal dementia(bvFTD). Patients with bvFTD have preserved language and memory function but display major impairments of insight, judgment, working memory, problem solving and other executive functions. Disinhibition in the areas of sexual misconduct, shop lifting, impulsive gambling are frequently seen and fail to elicit remorse. The major atrophy in these patients is seen in prefrontal cortex, caudate nucleus and the temporal poles. The principal focus of this talk will be PPA, a focal neurodegenerative syndrome characterized by an isolated and gradual dissolution of word finding and word usage. The language disturbance is initially the most salient deficit and the major obstacle to the execution of daily living activities. This does not mean that there are no deficits other than the aphasia, but that such additional deficits are relatively minor in the first two years following symptom onset. Some patients develop prominent agrammatism, others profound word comprehension(semantic)deficits. The speech output in PPA can be fluent or non-fluent. Memory, visual processing and personality remain relatively preserved during the initial stages. Terms such as progressive non fluent aphasia(PNFA)and semantic dementia(SD)have been used to denote subtypes of PPA. Structural and physiological neuroimaging confirms the selective predilection of PPA for language-related cortices of the left hemisphere. The majority of the autopsies in PPA have shown the neuropathology of FTLD but approxiametely 30% of PPA can be caused by atypical forms of AD neuropathology. The mechanisms that determine the initial selectivity of the cognitive impairment and the asymmetry of atrophy in PPA remain to be elucidated. An informed approach to PPA helps to address the challenges associated with the care of these patients. This syndrome also offers unique opportunities for exploring the cognitive architecture of language processing and the neurobiological fingerprints of the language network.
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  • Sandra Weintraub
    2011 Volume 13 Issue 2 Pages 154
    Published: 2011
    Released on J-STAGE: April 12, 2017
    JOURNAL FREE ACCESS
    Thirty years ago, neurodegenerative dementia was considered a neuroanatomically and functionally diffuse class of diseases, and, therefore, of no importance to understanding cognitive localization in the brain. Public awareness of neurodegenerative dementia has increased dramatically over the past 30 years, leading to much earlier diagnosis. In early stages of dementia, it has been shown that neurodegenerative changes are highly selective, targeting very specific cortical and subcortical regions and producing highly circumscribed cognitive deficits before they evolve into more generalized impairment. Four distinctive neuropsychological profiles of dementia, each associated with a different large-scale neuroanatomical network, will be contrasted with respect to their salient clinical features and associated neuroanatomical and neuropathologic signatures. An amnestic profile has been associated with medial temporolimbic dysfunction and most of these cases are diagnosed with pathologic Alzheimer’s disease at post mortem autopsy. The profile of primary progressive aphasia has been associated with structural and functional disruption in left perisylvian “language regions” and is neuropathologically heterogeneous with most cases due to one of the several forms of frontotemporal lobar degeneration(FTLD). An early profile of progressive visuospatial dysfunction has been associated with posterior cortical atrophy and hypometabolism in visual processing regions of the brain. At post mortem, this clinical profile is primarily linked with Alzheimer neuropathology in a distribution that favors visual association cortex. Finally, the syndrome marked by early progressive comportmental and executive function deficits is marked by frontotemporal atrophy and dysfunction and, at post mortem, with one of the many entities under the rubric of FTLD. The neurocognitive profile approach to dementia has led to important discoveries about how cognition is organized in the brain as well as to more effective diagnosis and management of these illnesses.
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  • Haruna Miyamura, Masayuki Satoh, Hiroyuki Kajikawa, Akihiro Sindo, Nob ...
    2011 Volume 13 Issue 2 Pages 189-197
    Published: 2011
    Released on J-STAGE: April 12, 2017
    JOURNAL FREE ACCESS
    We report a case with defective route finding who showed the improvement by the use of photo navigation map with heading arrows. The patient was a 81-year-old right-handed woman who lived alone. On October 20XX, she consulted department of neurology in our hospital because of the loss on a way to the bakery which was about 1 km away from her home since August 20XX. Physical, and neurological examination showed no abnormality. Although a brain MRI showed slight brain atrophy, 123 I-IMPSP ECT did not suggest significant hypoperfusion. In the neuropsychological assessment, MMSE score is 26/30. HDS-R score is 26/30. Unilateral spatial neglect and the prosopagnosia were not observed. A slight constructive disability was detected in Necker’s cube drawing. The test of topographical disorientation revealed not only defective route finding but also slight landmark agnosia. The only problem in her daily life was the round finding between home and the bakery and she could understand neighbor landmarks. We supposed that her topographical disorientation was mainly caused by defective route finding. We examined the patient’s topographical disorientation and how to rehabilitate by using a classification of Lynch. We prepared two pieces of maps with navigating photos and heading arrows ; one piece of map showed from home to the bakery, and another showed from bakery to her home. After the several trials using these maps, she could arrive at the bakery without them. We may say that photo navigation map with heading arrows is useful to the patient with defective route finding.
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