Exploring biomechanical differences between brain-first and body-first Parkinson's disease subtypes using shear wave...

Area of Science:

• Biomedical Engineering
• Neurology
• Medical Physics

Background:

• Parkinson's disease (PD) diagnosis and subtyping rely on clinical assessments, lacking objective biomechanical markers.
• Understanding muscle rigidity differences in PD subtypes is crucial for targeted therapies.

Purpose of the Study:

• To investigate ultrasound shear wave elastography (SWE) for quantifying muscle rigidity in PD.
• To assess biomechanical differences between brain-first and body-first PD subtypes using SWE.

Main Methods:

• Shear wave elastography measured Young's modulus (YM) and shear wave velocity (SWV) in biceps brachii of 102 PD patients and 70 healthy controls (HCs).
• PD patients were classified as body-first or brain-first based on RBDSQ criteria.
• Statistical analyses included t-tests, ANOVA, Pearson/Spearman correlations, and ROC analysis.

Main Results:

• PD patients exhibited significantly higher YM and SWV than HCs (p < 0.001).
• The body-first PD group showed significantly greater YM and SWV compared to the brain-first group (p < 0.001).
• SWE parameters correlated with clinical PD severity scores, and ROC analysis demonstrated diagnostic potential (AUC for YM/SWV: 0.844/0.845 for PD vs. HCs; 0.730/0.705 for body-first vs. brain-first PD).

Conclusions:

• Ultrasound shear wave elastography is a sensitive tool for quantifying rigidity in Parkinson's disease.
• This study provides initial evidence of distinct muscle biomechanical properties between PD subtypes.
• SWE shows promise as a supplementary biomarker for PD subtyping, warranting further multimodal and longitudinal investigation.