A synthetic kinematic index of trunk displacement conveying the overall motor condition in Parkinson\u2019s disease

Emahnuel Troisi Lopez,Pierpaolo Sorrentino,Rosaria Rucco,Valeria Agosti,Domenico Tafuri,Valentino Manzo,Roberta Minino,Giuseppe Sorrentino,Marianna Liparoti,Anna Carotenuto

doi:10.1038/s41598-021-82348-4

Abstract

Parkinson's disease (PD) is characterized by motor impairment, affecting quality of life and increasing fall risk, due to ineffective postural control. To this day, the diagnosis remains based on clinical approach. Similarly, motor evaluation is based on heterogeneous, operator-dependent observational criteria. A synthetic, replicable index to quantify motor impairment is still lacking. Hence, we have designed a new measure of postural stability which assesses the trunk displacement in relation to the center of mass, that we named trunk displacement index (TDI). Twenty-three PD patients and twenty-three healthy controls underwent motor examination through a stereophotogrammetric system. A correlation analysis was performed to assess the relationship of TDI with gait parameters and clinical motor scale (UPDRS-III). The TDI sensitivity was estimated, comparing pre- and post- L-DOPA subclinical dose intake. The TDI showed significant correlations with many gait parameters and with the UPDRS-III. Furthermore, the TDI resulted capable in discriminating between off and on state in PD, whereas gait parameters failed two show any difference between those two conditions. Our results suggest that the TDI may be considered a highly sensitive biomechanical index, reflecting the overall motor condition in PD, and provided of clinical relevance due to the correlation with the clinical evaluation.

Highlights

Parkinson’s disease (PD) is characterized by motor impairment, affecting quality of life and increasing fall risk, due to ineffective postural control
The aim of our study is to find an objective biomechanical index to synthetically convey the effect of the complex motor impairment in PD on stability
In this study we extracted from 3D-Gait Analysis (3D-GA) data, a biomechanical index, named trunk displacement index (TDI), capable of synthetically conveying the complex motor impairment of PD patients

Summary

Introduction

Parkinson’s disease (PD) is characterized by motor impairment, affecting quality of life and increasing fall risk, due to ineffective postural control. To this day, the diagnosis remains based on clinical approach. A correlation analysis was performed to assess the relationship of TDI with gait parameters and clinical motor scale (UPDRS-III). In order to keep balance, the cerebellum control does not operate on each muscle separately, but rather it aims to the control of the centre of mass (COM), integrating information with vestibulospinal information of trunk v erticality[17,18] Following this evolutionary reasoning, we took into consideration the well-known PD trunk impairment and the relative increased fall r isk[19]. In 2010, Roiz et al, through 3D-GA, measured trunk flexion on the sagittal plane in 12 PD patients and 15 healthy controls, with no statistically significant r esults[21]

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