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IC‐P‐130: Detecting preclinical neurodegeneration: An example from Huntington's disease
Author(s) -
Kloppel Stefan,
Chu Carlton,
Tan Geoffrey,
Draganski Bogdan,
Johnson Hans,
Paulsen Jane,
Kienzle Wolf,
Tabrizi Sarah,
Ashburner John,
Frackowiak Richard
Publication year - 2009
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.2009.05.102
Subject(s) - neurodegeneration , neuroimaging , disease , gold standard (test) , magnetic resonance imaging , atrophy , huntington's disease , preprocessor , medicine , pathology , artificial intelligence , neuroscience , computer science , biology , radiology
MRS prescriptions were placed on confluent WMH when visible. SPECT perfusion data was also acquired on a Phillips triple-head gamma camera. T1 tissue segmentation was performed using a previously published method2. WMH volumes were separately obtained using the program Lesion Explorer 3. Spectral profiles were obtained with the program LCmodel, with concentrations measured relative to creatine4. All images and series were coregistered to T1 space using AIR 5.05. Results: AD subjects showed a negative correlation between relative gray matter volume (GM) and glycerophosphocholineþphosphocholine/creatine (GPC þ PCh/Cr) (r 1⁄4 -0.587,p 1⁄4 0.005) and a positive correlation between GM and glutamateþ glutamine/creatine (Glu þ Gln/Cr) (r 1⁄4 0.538,p 1⁄4 0.012). NC’s showed a positive correlations between normal-appearing-white-matter (NAWM) and both N-acetyl-aspartate/creatine (NAA/Cr) (r 1⁄4 0.423,p 1⁄4 0.035) and GPC þ PCh/Cr (r 1⁄4 0.417,p 1⁄4 0.038). Additionally, SPECT perfusion negatively correlated with relative WMH volume within the MRS sampling voxels (r 1⁄4 -0.585,p 1⁄4 0.007). Conclusions: The presence of a positive relationship between NAA and NAWM in NC’s and the lack thereof in the AD subjects may indicate the comparative health of brain tissues in these groups with the AD group showing greater axonal comprise. The positive relationship between GM volume and Glu þ Gln/Cr in the AD group may reflect neurodegenerative glutamate toxicity. The perfusion correlation shows that the greater the volume of WMH, the greater the decrease in tissue perfusion. MRS can be useful for gaining valuable insight in to metabolic changes taking place in AD and the aging brain. This technique is being extended to a larger sample, and will incorporate diffusion tensor data within the MRS voxels to further understand the disease processes.