Presenter of 1 Presentation
EXAMINATION OF WHITE MATTER TRACTS IN PROGRESSIVE SUPRANUCLEAR PALSY VARIANTS BY DIFFUSION TENSOR IMAGING PARAMETERS, CONNECTOMICS, AND BRAIN NETWORK ANALYTICS.
Abstract
Aims
We aimed to apply different diffusion MRI (dMRI) techniques to characterize specific changes in white matter (WM) tracts from patients with progressive supranuclear palsy (PSP). We hypothesized that microstructural, connectomics, and network techniques, representing the superior cerebellar peduncle (SCP) and dentatorubrothalamic tract (DRTT) fibers, can differentiate autopsy-confirmed PSP Richardson’s syndrome (PSP-RS) and PSP with predominant speech and language disorder (PSP-SL).
Methods
Twenty-two autopsy-confirmed patients with PSP (12 PSP-RS and 10 PSP-SL) had undergone antemortem 3T head MRI, including diffusion tensor imaging (DTI). Deterministic tractography was used to identify the SCP and DRTT in each patient and fractional anisotropy (FA) and mean diffusivity (MD) were calculated for each tract. A hierarchical linear statistical model analysis was applied to the DTI dataset. Mean connectivity matrix strength was analyzed using Spearman’s correlation coefficients. Graph theory-based global and local network metrics such as network efficiency and small-wordness were also studied.
Results
Greater MD in SCP, as well as lower FA in DRTT fibers, was observed in PSP-RS compared to PSP-SL. DRTT connectivity analysis showed a greater decrease in general connectivity strength and infra-thalamic network circuitry in PSP-RS compared to PSP-SL. While both PSP subtypes showed similar reductions in network complexity measured as small-worldness, lower global network density and efficiency were seen in PSP-RS.
Conclusions
Our outcomes demonstrate that is possible to increase diagnostic discrimination between PSP subtypes by combining diverse structural dMRI techniques. These findings could help physicians improve the assessment and follow-up in this patient population.