Agessandro Abrahao (Canada)
Sunnybrook Health Sciences Centre Sunnybrook Research InstituteAuthor Of 1 Presentation
MRI BIOMARKERS OF NEUROINFLAMMATION ACROSS NEURODEGENERATIVE DISEASES: FREE WATER DIFFUSION IN THE ONTARIO NEURODEGENERATIVE DISEASE RESEARCH INITIATIVE (ONDRI) COHORT
Abstract
Aims
Free-water diffusion (FWD), a diffusion MRI metric, is a non-specific marker of neuroinflammation. Given previous research implicating neuroinflammation in the pathogenesis of neurodegenerative disorders, we examined FWD across neurodegenerative diseases.
Methods
Diffusion and structural MRI data from the ONDRI cohort was used to generate FWD maps in a preliminary dataset of 230 subjects (108 Alzheimer’s Disease (AD)/Mild cognitive impairment (MCI), 32 Amyotrophic Lateral Sclerosis (ALS), 33 Frontotemporal Dementia (FTD), 21 Parkinson’s Disease (PD), 36 Vascular Cognitive Impairment (VCI). FWD maps were generated according to Pasternack et al., (2009) using MATLAB, prior to PLS analysis (1000 permutations and 100 bootstraps). Post-hoc one-way ANOVA and Tukey’s highest significant difference (HSD) tests were conducted in significant ROIs determined through PLS.
Results
PLS revealed two significant latent variables (LV1 and LV2). LV1 explained 66% of the sample variance and separated ALS and PD from ADMCI, FTD and VCI. LV2 explained 18% of the sample variance and separated ALS from ADMCI, FTD, PD and VCI. Significant clusters were observed in the insula, caudate nuclei, temporal and frontal cortices, left hippocampus, cerebellum, and mammillary bodies. In all included ROI’s, there was a significant effect of group (p <0.05) as identified through ANOVA. Tukey’s HSD revealed two patterns in the dataset i) ALS and PD had significantly lower FWD compared to ADMCI, FTD and VCI within the caudate nuclei and inferior temporal gyri and ii) PD has significantly lower FWD compared to ALS, ADMCI, FTD and VCI in the left hippocampus.
Conclusions
In this preliminary dataset, regionally specific differences in FWD were observed across neurodegenerative diseases. Regional inflammation may play a role in selective neuronal and region-specific vulnerability across these diseases.