Abstract Details

Title Tractography Examination of Dentato-rubro-thalamic Tract in Autopsy-confirmed Variants of Progressive Supranuclear Palsy.

Topic Behavioral and Cognitive Neurology

Presentation(s) S2 - Behavioral Neurology (1:36 PM-1:48 PM)

Poster/Presentation
Number 004

Background

Diffusion tensor Imaging (DTI) can be used to assess microstructural damage of SCP and DRTT in PSP Richardson’s syndrome (PSP-RS) and PSP with a predominant speech and language disorder (PSP-SL). No studies have assessed these two tracts in clinical variants from an autopsy confirmed PSP cohort.

Objective

To compare the integrity of the superior cerebellar peduncle (SCP) and dentato-rubro-thalamic tract (DRTT) across two clinical variants of progressive supranuclear palsy (PSP) that had autopsy confirmation of PSP pathology.

Design/Methods

Twenty autopsy-confirmed patients with PSP pathology (10 PSP-RS and 10 PSP-SL) had undergone antemortem 3T head MRI. DTI was used for whole-brain tractography reconstructions of brain fiber bundles and to identify the SCP and DRTT. From each tract, fractional anisotropy (FA) and mean diffusivity (MD) were calculated. Kruskal-Wallis (KW) rank-sum test and hierarchical linear model (HLM), were applied. Diffusivity parameters were correlated to the following clinical scales PSP Saccadic Impairment Scale (PSIS), PSP rating scales, and Unified Parkinson's Disease Rating Scale part III (MDS-UPDRS III).

Results Greater MD in SCP (p <0.004), as well as lower FA in DRTT fibers, was observed in PSP-RS compared to PSP-SL (p <0.037). DRTT global and local network analysis also revealed greater decrease in infra-thalamic network circuitry in the PSP-RS group. Significant correlations were found in PSP-SL between FA and PSIS for the SCP (p <0.042) and DRTT (p <0.022) and between FA and PSP rating scale (p <0.008) and FA and UPDRS III (p <0.014) for the SCP.

Conclusions

Tractography changes show that phenotypical variability in PSP is likely related to differential impairment in the the SCP and DRTT.

Authors/Disclosures
Rodolfo G. Gatto, MD, PhD (Mayo Clinic Neurology and Neurosurgery) PRESENTER	Dr. Gatto has nothing to disclose.
	No disclosure on file
Farwa Ali, MD (Mayo Clinic)	Dr. Ali has nothing to disclose.
Heather Clark	No disclosure on file
Joseph Duffy	No disclosure on file
Rene Utianski	No disclosure on file
Hugo Botha, MD (Mayo School of Graduate Medical Education, Rochester)	Dr. Botha has received research support from NIH.
Mary M. Machulda, PhD (Mayo Clinic)	The institution of Dr. Machulda has received research support from NIH.
J. E. Ahlskog, MD, PhD (Mayo Clinic)	Dr. Ahlskog has received publishing royalties from a publication relating to health care.
Dennis W. Dickson, MD (Mayo Clinic)	Dr. Dickson has nothing to disclose.
Keith A. Josephs, Jr., MD, FAAN (Mayo Clinic)	Dr. Josephs has nothing to disclose.
Jennifer Whitwell, PhD (Mayo Clinic)	Dr. Whitwell has nothing to disclose.