Assessing Structural MRI Changes in Patients with Parkinson's Disease-Freezing of Gait
Poster No:
254
Submission Type:
Abstract Submission
Authors:
Alan Gardner1, Saul Lopez1, Zoltan Mari2, Virendra Mishra1
Institutions:
1The University of Alabama at Birmingham, Birmingham, AL, 2Cleveland Clinic Foundation, Las Vegas, NV
First Author:
Co-Author(s):
Introduction:
Morphological studies utilizing T1-weighted (T1) magnetic resonance imaging (MRI) can provide insight into the structural brain changes such as volume, cortical thickness, cortical area, and local gyrification index (LGI) in patients with Parkinson's disease (PD) experiencing Freezing of Gait (FoG) by Utilizing FreeSurfer 7.0, the aforementioned T1-derived measures can be accurately estimated and offer insight into the pathophysiological
underpinnings of FoG. We hypothesize that PD-FoG will exhibit distinctive cortical morphological differences when compared to PD patients without FoG (PD-nFOG) and healthy controls (HC). More specifically, we expect to observe differences in cortical area, volume, curvature, and thickness across the three groups, providing further insights into the structural variations associated with FoG in PD. Moreover, we expect to see a decreased LGI in the PD-FoG cohort, indicative of altered cortical folding patterns.
underpinnings of FoG. We hypothesize that PD-FoG will exhibit distinctive cortical morphological differences when compared to PD patients without FoG (PD-nFOG) and healthy controls (HC). More specifically, we expect to observe differences in cortical area, volume, curvature, and thickness across the three groups, providing further insights into the structural variations associated with FoG in PD. Moreover, we expect to see a decreased LGI in the PD-FoG cohort, indicative of altered cortical folding patterns.
Methods:
A total of 53 individuals were recruited at Cleveland Clinic Lou Ruvo Center for Brain Health. Among these, 16 participants were categorized as PD-FoG, 21 were PD-nFoG, and 16 were HC. The diagnosis of FoG was determined by a movement disorders specialist using direct observation of the participants. This assessment took place within the context of a tailored physical therapy task deliberately designed to elicit instances of freezing of gait. All participants utilized in this study underwent a comprehensive MRI examination and were scanned with the following T1-weighted MRI acquisition parameters on a 3T Siemens Skyra MRI scanner: resolution=1mm...3, TR/TE=2300/2.96ms. Following the guidelines outlined by Freesurfer developers, the acquired MRI data underwent the FreeSurfer 7.0 processing pipeline. Freesurfer performed an automated segmentation of brain structures and parcellation of various brain regions. Area, volume, curvature, thickness, and LGI were computed within this framework. To verify quality and reliability, the data underwent a dual quality check process that encompassed both manual and automatic methods. The manual method consisted of viewing the reconstructed T1 images of all patients and checking for any errors in their segmentation. If there were any segmentation errors, the errors were corrected manually. The automatic quality check method involved the utilization of the Computational Anatomy Toolbox (CAT). Following the quality check, we eliminated two of our participants. We then extracted the morphological values from each region identified in the Desikan-Killiany atlas from each participant. The statistical comparison and correlational analyses were executed using the Permutation Analysis of Linear Models (PALM) toolbox integrated within FSL. To account for potential confounding variables, we regressed for sex, handedness, levodopa equivalent daily dose, unified Parkinson's Disease Rating Scale scores, and intracranial volume. The results were considered significant at familywise error corrected (FWE) p...corr<0.05.
Results:
The cortical volumes of the mid-posterior corpus callosum, medial orbitofrontal cortex, superior frontal cortex, and lingual cortex; cortical areas of the superior frontal, superior parietal, and medial orbitofrontal cortices; and cortical thickness of the middle temporal cortex, right pars orbitalis, and right posterior cingulate cortex were significantly (p...corr<0.05) different between the groups (Fig.1). Regardless of the FoG status, HC showed a trend-level (p...corr<0.1) decreased LGI in the parahippocampal cortex and frontal pole. PD-FoG showed a trend-level (p...corr<0.1) higher LGI across the same regions when compared to PD-nFOG.
·Areas with significant changes
Conclusions:
Our analysis suggested that significant morphological differences exist between PD-FoG, PD-nFOG, and HC. The increased LGI experienced in PD-FOG potentially contributes to the manifestation of FoG in PD.
Disorders of the Nervous System:
Neurodegenerative/ Late Life (eg. Parkinson’s, Alzheimer’s) 1
Neuroanatomy, Physiology, Metabolism and Neurotransmission:
Cortical Anatomy and Brain Mapping 2
Keywords:
Data analysis
MRI
Neurological
STRUCTURAL MRI
1|2Indicates the priority used for review