Refining Structural MRI Changes in Essential Tremor: Recursive Elimination of Features with GMLVQ

Poster No:

253 

Submission Type:

Late-Breaking Abstract Submission 

Authors:

Alma Socorro Torres-Torres1, Jelle Dalenberg2, Remco Renken2, Michael Biehl3, Marina de Koning-Tijssen2

Institutions:

1University Medical Center Groningen, Groningen, NM, 2University Medical Center Groningen, Groningen, Groningen, 3University of Groningen, Groningen, Groningen

First Author:

Alma Socorro Torres-Torres  
University Medical Center Groningen
Groningen, NM

Co-Author(s):

Jelle Dalenberg  
University Medical Center Groningen
Groningen, Groningen
Remco Renken  
University Medical Center Groningen
Groningen, Groningen
Michael Biehl  
University of Groningen
Groningen, Groningen
Marina de Koning-Tijssen  
University Medical Center Groningen
Groningen, Groningen

Introduction:

ET is a prevalent movement disorder, affecting approximately 1.3% of the global population [1]. Characterized by involuntary oscillatory postural tremors in the upper limbs, ET significantly impacts daily activities and reduces quality of life. Structural MRI studies suggest widespread gray and white matter alterations; however, the specific structural patterns contributing to ET remain unclear [2]. Employing interpretable classification models, such as GMLVQ-driven feature selection, may enhance biomarker discovery for ET.
This study aims to optimize the identification of structural MRI biomarkers in Essential Tremor (ET) by applying Generalized Matrix Learning Vector Quantization (GMLVQ) for classification against healthy volunteers (HV) using ROI features derived from probability maps to identify the most informative ones.

Methods:

Twenty ET patients from the Next Move in Movement Disorders (NEMO) project [3] and twenty age-matched healthy volunteers (HV) were included. T1-weighted MRI scans were preprocessed as described in [4] and further processed with FreeSurfer (v7.4.1) to obtain gray matter probability (GMP) and white matter probability (WMP) maps.
For each subject, GMP and WMP maps were used to extract regions of interest (ROIs) based on the AAL3 atlas. From each ROI, four voxel distribution features-mean, standard deviation (STD), kurtosis, and skewness-were extracted, serving as input features for classification.
To enhance ROI feature selection, we integrated recursive feature elimination (RFE) with Stratified K-Fold cross-validation (k=5). Using GMP and WMP maps, we investigated structural MRI alterations distinguishing ET from HV, ensuring feature robustness through permutation testing. RFE with GMLVQ was implemented, iteratively removing the least informative voxel clusters based on feature relevance extracted from GMLVQ's Omega matrix. After model convergence, permutation importance was applied to validate feature stability across folds. Statistical significance was set at p < 0.001, FDR-corrected (α = 0.05).

Results:

The RFE with GMLVQ achieved high classification performance (AUC = 0.91 for GMP, AUC = 0.86 for WMP). The most informative GMP ROIs distinguishing ET from HV were the left pulvinar thalamic nucleus, right cerebellum (III-IX), and left cerebellum (IV-V). For WMP, the most discriminative ROIs were the left pulvinar thalamic nucleus, right cerebellum (III-IX), left cerebellum (III-V), and right posterior cingulate gyrus.

Conclusions:

Our findings demonstrate the effectiveness of RFE with GMLVQ in identifying discriminative structural MRI biomarkers for ET classification. The pulvinar thalamic nucleus and cerebellum emerged as key differentiating regions [5-8], reinforcing the role of the cerebello-thalamo-cortical network in ET pathophysiology.

Disorders of the Nervous System:

Neurodegenerative/ Late Life (eg. Parkinson’s, Alzheimer’s) 1

Modeling and Analysis Methods:

Classification and Predictive Modeling 2
Multivariate Approaches
Segmentation and Parcellation

Keywords:

Cerebellum
Machine Learning
Movement Disorder

1|2Indicates the priority used for review

Abstract Information

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Please indicate below if your study was a "resting state" or "task-activation” study.

Other

Healthy subjects only or patients (note that patient studies may also involve healthy subjects):

Patients

Was this research conducted in the United States?

No

Were any human subjects research approved by the relevant Institutional Review Board or ethics panel? NOTE: Any human subjects studies without IRB approval will be automatically rejected.

Yes

Were any animal research approved by the relevant IACUC or other animal research panel? NOTE: Any animal studies without IACUC approval will be automatically rejected.

Not applicable

Please indicate which methods were used in your research:

Structural MRI

For human MRI, what field strength scanner do you use?

1T

Which processing packages did you use for your study?

Free Surfer

Provide references using APA citation style.

1. E. D. Louis and M. McCreary, “How Common is Essential Tremor? Update on the Worldwide Prevalence of Essential Tremor,” Tremor and Other Hyperkinetic Movements, vol. 11, no. 1, 2021.
2. Luo, R., Pan, P., Xu, Y., & Chen, L. No reliable gray matter changes in essential tremor. Neurological Sciences. 2019 https://doi.org/10.1007/s10072-019-03933-0
3. A. M. M. van der Stouwe et al., “The next move in movement disorders (NEMO): developing a computer aided classification tool for hyperkinetic movement disorders.,” BMJ Open, 2021.
4. J. R. Dalenberg et al., “Next move in movement disorders: neuroimaging protocols for hyperkinetic movement disorders,” Front. Hum. Neurosci., vol. 18, p. 1406786, Aug. 2024.
5. Cameron, E., Dyke, J., Hernandez, N., Louis, E., & Dydak, U. Cerebral gray matter volume losses in essential tremor: A case-control study using high resolution tissue probability maps.. Parkinsonism & related disorders. 2018; 51. https://doi.org/10.1016/j.parkreldis.2018.03.008
6. Benito‐León, J., Alvarez-Linera, J., Hernandez-Tamames, J., Alonso-Navarro, H., Jiménez-Jiménez, F., & Louis, E. Brain structural changes in essential tremor: Voxel-based morphometry at 3-Tesla. Journal of the Neurological Sciences. 2009; 287. https://doi.org/10.1016/j.jns.2009.08.037
7. Younger, E., Ellis, E., Parsons, N., Pantano, P., Tommasin, S., Caeyenberghs, K., Benito‐León, J., Romero, J., Joutsa, J., & Corp, D. Mapping Essential Tremor to a Common Brain Network Using Functional Connectivity Analysis. Neurology. 2023; 101. https://doi.org/10.1212/WNL.0000000000207701
8. Pietracupa, S., Bologna, M., Tommasin, S., Berardelli, A., & Pantano, P. The Contribution of Neuroimaging to the Understanding of Essential Tremor Pathophysiology: a Systematic Review. The Cerebellum. 2021; 21. https://doi.org/10.1007/s12311-021-01335-7

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