Reliability and Validity of Sensor-derived Measurements in Individuals With Parkinson's Disease: Preliminary Results From the INERTIAL Study

Reliability and Validity of Sensor-derived Measurements in Individuals With Parkinson's Disease: Preliminary Results From the INERTIAL Study

Parkinson's disease (PD) is a neurodegenerative disorder that affects a significant portion of the elderly population. Gait disturbance is a core symptom of the disease and can impact stride length and height, gait speed, trunk sway, and the pendular movement of the arms. This impairment is often accompanied by postural alterations, balance difficulties, and an increased risk of falls. Additionally, freezing and festination phenomena may also occur.

Inertial Movement Units are inertial sensors that are used for monitoring clinical and identification of movement biomarkers in patients with neurodegenerative diseases. In particular, among existing devices based on IMUs, prototype versions of SensMode have shown promising results in identifying objective indices to support diagnosis and monitoring in patients with PD. Recent work shows that the aforementioned wearable sensors during some tasks of the MDS-UPDRS have excellent discriminative property between subjects healthy and those with PD.

The aim of the present research project is to investigate the potential of sensors in measuring limb movement in subjects with Parkinson's Disease.

In detail, the primary objective of this project is to evaluate the reliability of measurements obtained from sensors used for measuring limb movement in subjects with PD. Specifically, the inter-rater and intra-rater reliability of measurements recorded with inertial sensor, during the execution of some items of Section III of the MDS-UPDRS. In addition, the study aims to assess the validity of the measurements obtained from the inertial sensor set by comparing them with clinical data in a sample of patients with PD.

Specifically, the objectives of the study are as follows:

• The verification of the reliability of sensor-derived measurements; in particular, the inter-rater and intra-rater reliability of measurements recorded with inertial sensor, while performing of some items of Section III of the MDS-UPDRS.
• The verification of the validity (criterion validity) of the experimental device-derived measurements during the execution of the items of Section III of the MDS-UPDRS involving limbs.

The data to be collected will include: demographic variables, clinical variables (Montreal Cognitive Assessment - MoCA; Clinical Instability Scale - CIS; Hoehn and Yahr stage - H&Y; MDS-UPDRS Part III), instrumental variables (recorded by inertial sensors). Inclusion criteria for participant selection are: age over 18 years, diagnosis of PD according to the Postuma criteria, Hoehn and Yahr stages I-IV, and signed informed consent. Exclusion criteria include: presence of severe comorbidities, significant cognitive impairment, or signs of clinical instability.

Inclusion Criteria:

• Age greater than or equal to 18 years
• Diagnosis of Parkinson's disease (PD) according to Postuma criteria
• Hoehn and Yahr stages I-IV
• Signed informed consent provided by the participant or, when necessary, by a legal guardian or court-appointed representative

Exclusion Criteria:

• Severe comorbid conditions that may alter the subject's motor function
• Cognitive impairment severe enough to prevent cooperation during the execution of the protocol
• Presence of clinical instability, defined as a score greater than zero on the Clinical Instability Scale (CIS)