AffiliationDiscipline of Psychiatry, School of Medicine and Trinity College Institute of, Neuroscience (TCIN), Laboratory of Neuroimaging & Biomarker Research, Trinity, College Dublin, The Adelaide and Meath Hospital incorporating the National, Children's Hospital (AMiNCH), Dublin 24, Ireland.
MeSHAlzheimer Disease/complications/*pathology/radionuclide imaging
Image Processing, Computer-Assisted
Magnetic Resonance Imaging/methods
Nerve Net/*pathology/*physiopathology/radionuclide imaging
Neural Pathways/pathology/physiopathology/radionuclide imaging
MetadataShow full item record
CitationProg Neurobiol. 2009 Oct;89(2):125-33. Epub 2009 Jun 26.
JournalProgress in neurobiology
AbstractFindings derived from neuroimaging of the structural and functional organization of the human brain have led to the widely supported hypothesis that neuronal networks of temporally coordinated brain activity across different regional brain structures underpin cognitive function. Failure of integration within a network leads to cognitive dysfunction. The current discussion on Alzheimer's disease (AD) argues that it presents in part a disconnection syndrome. Studies using functional magnetic resonance imaging, positron emission tomography and electroencephalography demonstrate that synchronicity of brain activity is altered in AD and correlates with cognitive deficits. Moreover, recent advances in diffusion tensor imaging have made it possible to track axonal projections across the brain, revealing substantial regional impairment in fiber-tract integrity in AD. Accumulating evidence points towards a network breakdown reflecting disconnection at both the structural and functional system level. The exact relationship among these multiple mechanistic variables and their contribution to cognitive alterations and ultimately decline is yet unknown. Focused research efforts aimed at the integration of both function and structure hold great promise not only in improving our understanding of cognition but also of its characteristic progressive metamorphosis in complex chronic neurodegenerative disorders such as AD.