Parkinson¿s disease (PD) is a neurodegenerative disorder of the central nervous system affecting 1% of the population over 55 years of age and 2% of the population over 70 years. Although widely studied, this pathology still presents untapped aspects of motor symptoms, needing for a deeper and more accurate investigation. Among other symptoms, this research project focuses on alteration in posture and balance recovery strategies in perturbed conditions. The final goal of this study, in particular, is the accurate characterization of anticipatory postural adjustments (APAs) in PD patients and in patients with a group of motor disorders, similar to PD for symptomatology, but different for etiology, the so-called atypical parkinsonian syndromes (APs). Research is needed in this group of pathologies to help clinicians in the identification of indices for differential diagnosis with respect to PD. Toward this goal, the present research project represents the first step, concerning the development of a setup for measurement of APAs in subjects in perturbed postural conditions. In particular, the project will be aimed at the design and development of a robotic platform, rotating around the vertical axis, with programmable angle, speed and acceleration ranges. The device, will be inspired to typical balance evaluation performed by clinicians, but designed for enhancing effectiveness and repeatability. Two measurement systems for human kinematic (IMUs) and muscle activation (EMG) will be included and synchronized with the platform, to accurately measure postural adjustments in response to perturbation in both healthy controls and patients with PD. Outcomes of the study will enlarge knowledge on APAs alterations in patients with PD and will pave the way for the future experimental stage of applying the setup to patients with APs, dramatically impacting effectiveness in differential diagnosis of these pathologies also in an earlier stage.
The outcome of this research project are expected to enlarge the scientific knowledge on APs, through the involvement of advanced technologies for quantification of motor disorders. Although observation of motor characteristics of patients with APs suggested the existence of typical patterns helpful for diagnosis, the absence of specific measurement techniques made difficult an objective quantification. The development of a specific, yet scalable, setup for perturbed posturography and muscular activation, would permit to enhance knowledge on a relatively rare group of motor disorders. Such an advancement is expected to be both vertical, i.e. permitting to deeply reveal and accurately measure a particular characteristic, and horizontal, allowing for a comparative analysis of those characteristics in different pathology populations.
Beside the great opportunity coming from the measurement technology, the novelty of this research project lies also in the possibility to elicit some typical postural responses through a programmable perturbation. The electromechanical system to develop will allow the clinical research part to adjust rotation angle, direction, speed, and acceleration, in certain ranges, to simulate, in a repeatable way some postural perturbation deriving from daily activities, or usually imposed by specialists for sake of evaluation. The opportunity of using an automatic device for applying perturbation to the subject, is expected to enhance elicitation of typical motor patterns, making them evident and measurable even in an earlier stage than the usual observable onset.
The combination of the precision and repeatability in applying the perturbation, and the sensitivity and accuracy of the measurement systems, would expectedly identify specific motor indices for permitting a differential diagnosis of APs form PD in an earlier stage of the disease, dramatically increasing treatment timeliness and efficacy, and patients¿ quality of life.
Although many studies in the last years focused on objective quantification of motor symptoms in PD, the present study eventually targets at a group of pathologies presenting a lower incidence, where the enrollment of a sufficient number of patients for an experimental study is challenging. The possibility to enroll patients from the Department of Neurology and Psychiatry of Sapienza, that will inform and advise the project, represents a great opportunity to shed light on this poorly investigated group of pathologies.