'Characterizing levodopa-induced dyskinesias using neuroimaging, clinical and behavioural measures'
Poster No:
307
Submission Type:
Abstract Submission
Authors:
Sakshi Shukla1, Roopa Rajan2, Sule Tinaz3, Nivethida Thirugnanasambandam1
Institutions:
1Indian Institute of Technology, Mumbai, Maharashtra, 2All India Institute of Medical Sciences, New Delhi, New Delhi, 3Yale School of Medicine, New Haven, CT
First Author:
Co-Author(s):
Introduction:
Levodopa-induced dyskinesia (LID) is a motor complication that arises after chronic dopaminergic therapy in over 40% of patients with Parkinson's disease (PD). Studies have shown that patients with LID show distinct changes in brain morphology and resting state functional connectivity as compared to their non-dyskinetic counterparts. However, there is lack of understanding of how task-specific cortico-subcortical networks are differentially modulated in these patient groups. In this current study, our objective is to investigate potential differential modulation in motor and executive function networks among patients with LID, and to explore its correlation with brain morphology, clinical characteristics and behavioral parameters. Employing such a multimodal approach will deepen our understanding of the pathophysiology of LID and enable identification of specific functional networks for targeted therapeutic neuromodulation.
Methods:
We collected structural, resting-state and task-based functional MRI data from 17 DysPD patients, 15 nonDysPD patients, and 21 age- and sex-matched healthy subjects. Patients with mild to moderate PD (Hoehn & Yahr scale ≤ 3) and with unimpaired cognitive functioning (Montreal Cognitive Assessment score ≥ 24) were recruited. MRI was recorded on a 3T Siemens Magnetom Prisma scanner with a 64-channel head coil. The obtained structural T1-weighted data were processed using FreeSurfer v6.0.0 to extract volume, surface area and thickness measurements of subcortical and cortical regions. Region-based statistical analysis was performed using SPSS version 29.
Results:
All three groups were similar in age, sex and cognitive score. Vertex-based analysis showed that DysPD patients had significantly larger cortical volume (p-corrected =0.0002) in the sensorimotor region compared nonDysPD patients. However, cortical surface area and thickness were not significantly different across subject groups at the whole-brain and region-based level. Behavioural and functional connectivity analyses are currently ongoing and will be ready for presentation at the conference.
·Demographic and clinical characteristics of all participants across the groups in this study.
·Freesurfer whole-brain vertex-wise analysis of cortical volume. Statistical map displaying the significant cluster (yellow) near the postcentral gyrus between patients with LID and without LID.
Conclusions:
In this study, we found an increase in the cortical volume around the sensorimotor region of DysPD patients compared to the nonDysPD group. Such increased volume may indicate white matter inflammation with chronic dopaminergic therapy in dyskinesia. Although others have shown increased volume in the inferior frontal gyrus and supplementary motor areas, we have observed changes only in the sensorimotor region. Next steps in our ongoing analyses involve examining the relationship of these structural differences with resting-state and task-specific functional brain networks. The findings of our research will shed light on the role of distinct task-specific functional brain networks in characterizing patients with LID and their relevance to novel therapeutic strategies.
Disorders of the Nervous System:
Neurodegenerative/ Late Life (eg. Parkinson’s, Alzheimer’s) 1
Higher Cognitive Functions:
Executive Function, Cognitive Control and Decision Making
Modeling and Analysis Methods:
Activation (eg. BOLD task-fMRI)
Segmentation and Parcellation
Novel Imaging Acquisition Methods:
Multi-Modal Imaging 2
Keywords:
Other - Levodopa-Induced Dyskinesia, Parkinson's Disease, Volumetry, Freesurfer, Functional connectivity
1|2Indicates the priority used for review
Provide references using author date format
Choi, Yera et al. (2020) “Spatiotemporal dissociation of fMRI activity in the caudate nucleus underlies human de novo motor skill learning.” Proceedings of the National Academy of Sciences of the United States of America vol. 117.
Herz, Damian M et al. (2016), “Resting-state connectivity predicts levodopa-induced dyskinesias in Parkinson's disease.” Movement disorders : official journal of the Movement Disorder Society vol. 31.
Li, Weihua et al. (2020), “Longitudinal functional connectivity changes related to dopaminergic decline in Parkinson's disease.” NeuroImage. Clinical vol. 28.
Youn, Jinyoung et al. (2022), “Pallidal Structural Changes Related to Levodopa-induced Dyskinesia in Parkinson's Disease.” Frontiers in aging neuroscience vol. 14.