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PL‐01‐02: Imaging in dementia: Distinguishing diseases and measuring progression
Author(s) -
Fox Nick C.
Publication year - 2008
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2008.05.180
Subject(s) - dementia , neuroimaging , disease , medicine , magnetic resonance imaging , context (archaeology) , neuroscience , functional imaging , pathology , psychology , radiology , psychiatry , biology , paleontology
Background: The advent of potential disease-modifying therapies for neurodegenerative dementias has increased the need for biomarkers to improve early diagnosis and differential diagnosis. There is also a pressing need for biomarkers of progression in the different diseases. In all these areas neuroimaging has potential. Ideally we would have reliable noninvasive markers that could predict, differentiate and track specific molecular pathologies (e.g. Alzheimer’s disease or other causes) from a predementia or even pre-symptomatic stage. Methods: I will review progress that has been made in using imaging to detect early structural, functional and metabolic changes associated with Alzheimer’s disease and related disorders and what this work has told us about how these diseases start and progress. I will discuss the extent to which it is possible to distinguish different causes of dementia and how imaging is being considered as a means of measuring progression and of assessing therapeutic effects in trials. I will focus on magnetic resonance imaging (MRI) but will set this in the context of other imaging modalities Results: Imaging has provided remarkable insights into how and when molecular pathologies affect the brain in dementia. These insights have come from a number of different and complementary imaging approaches. The degenerative dementias appear to have in common an insidious onset of changes which predate clinical diagnosis by several years. The different diseases can increasingly be distinguished by their signatures on molecular imaging or by the different topography of loss of structure or function within the brain. Imaging markers can be used to track progression and to understand the natural history of disease. These findings have led to a number of imaging measures being proposed as outcomes in trials. The measurement of therapeutic effect remains challenging however and imaging results need to be interpreted cautiously and in the context of the clinical outcomes. Conclusions: Imaging has a growing role in improving early diagnosis in dementia and may in the future contribute to the identification of therapies for these devastating diseases.