Effect of a Progressive Treadmill Training Protocol for Parkinson's Disease

Biomarkers of Rehabilitation Outcome in Patients With Parkinson's Disease: Effect of a Customized Protocol on Treadmill Training With and Without Augmented Virtual Reality Application, a Randomized Controlled Trial

The primary objective of this single-center, no-profit, longitudinal interventional randomized controlled, single-blind trial is to compare the effects of 2 different treadmill training treatments using C-Mill: the experimental one, endowed with augmented virtual reality (AVR) applications, versus the conventional one, the standard treadmill training in PD patients with gait and or balance disturbances. The main questions the study aims to answer are 1) Is the experimental treatment more effective than the conventional one? 2) Is it possible to identify predictive and indicative biomarkers of an outcome measure of rehabilitation using extracellular vesicles (cEVs) assessed by Raman spectroscopy? Participants will be randomized into two groups: the experimental group that will receive the experimental intervention, and the control group that will receive the conventional intervention. Both groups will train three times per week for 8 weeks, the first session starting from 25 minutes (25'). The experimental and the conventional treatments are planned to be progressive and will be individualized to the participant's level of performance. Clinical, neuropsychological, and instrumental variables will be collected at baseline (T0), at the end of the treatment (T1), and 3 months after the end of treatment (T2). At 6 months after the end of treatment (T3), a phone interview will be performed. Both within-group and between-group analyses will be conducted. Biosamples will be collected at baseline (T0) and at the end of treatment (T1).

Study design: single-center, no-profit, randomized controlled single-blind trial (clinicians that assessed the effect of the interventions will be blind), with an active comparator. The study reflects the design of superiority of the experimental treatment versus the standard one. The treatment arm will be assigned by randomization. The results obtained with the 2 treatments will be compared. The sponsor of the study is the Department of Clinical and Experimental Medicine, University of Florence, Italy; the study will be performed at "Struttura Organizzativa Dipartimentale (SOD) di Riabilitazione Generale- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Fondazione Don Carlo Gnocchi, Florence". Collaborators for external services: Movement Analysis Laboratory at IRCCS Don Carlo Gnocchi Florence Laboratory of Nanomedicine and Clinical Biophotonics (LABION) at IRCCS Don Carlo Gnocchi Milan Study start and length: study started on 6 July 2022 and will terminate on December 2023. Study length for single participant 8 months: enrollment and baseline assessment (T0), treatment (2 months duration), end-of-treatment assessment (T1), follow-up assessment at 3 months after the end of treatment (T2), telephone interview at 6 months after the end of treatment. Primary objective: to compare the effects of an integrated rehabilitation intervention using a new treadmill training that includes AVR applications, versus a conventional treadmill-based intervention in patients with PD (Hoehn and Yahr stage II-III) affected by walking and or balance disorders. Secondary objective: to stratify PD patients based on their biological profile and identify predictive biomarkers and biomarkers indicative of an outcome measure of rehabilitation. Description of the intervention. The intervention includes three sessions per week for 8 weeks. The intervention will be delivered during the "on" time of patients, every day at the same time. The experimental and the conventional treatments are planned to be progressive and customizable to the participant's level of performance: progression in gait speed: gait speed is set at 80% of the individual's overground walking speed at the beginning of training, and will be weekly progressively increased to a maximum of 120% progression in trial duration: at the beginning of training, the duration is set at 25 minutes, including 5 slots of exercises lasting 5 minutes, with a 4-minute rest between each slot; every two weeks it will be increased by 1 minute per slot, reaching a maximal duration of 45 minutes in the last two weeks of treatment; progression in trial difficulty (only for the experimental group): the protocol has 5 difficulty levels for each C-Mill application, and the transition among levels is set at 80% success achievement. Safety measures: participants will exercise wearing an anti-fall device and heart rate control; when the heart rate exceeds the safety threshold (set at 75% of HRmax, i.e., 220-age for males; 200-age for females), the treadmill speed will be lowered until the parameter is normalized. Motek's C-Mill is a newly developed treadmill for gait and balance assessment and training that will be used for the study in both groups in a safe way (with an anti-fall device application and heart rate control). It is a treadmill sensor inclusive of a force platform. The patient is instructed to avoid using the side support bars during the training. The AVR applications of the C-Mill included in the training protocol are "nature island", "stepping stones", "walking area", "obstacles avoidance", and "tracks". These applications train balance and changes in walking speed, promote gait adaptation strategies and strategies to overcome freezing of gait, in a safe and controlled environment. Moreover, feedback to promote proper walking is provided (by physiotherapists and applications) including feedback on gait parameters such as stride symmetry, stride length, and cadence. Visits planning and assessment timing Clinical, neuropsychological, and instrumental variables will be collected at baseline (T0), at the end of the treatment (T1), and 3 months after the end of treatment (T2). At 6 months after the end of treatment (T3) a phone interview will be performed. All the assessments will be performed at each time point (T0, T1, T2) with some exceptions: automatic acquisition of gait parameters using C-Mill in C-Gait mode will be collected only at T1 and T2; at the end of treatment (T1), a 5-point Likert scale will also be administered to register patient satisfaction; during the phone interview at T3 only the falls questionnaire will be administered. All visits will be planned in the "on" time of patients. Pharmacological treatments should be stable until T1. Definition of adherence: adherence to the intervention will be considered sufficient if the patient respects the times and methods of execution of the rehabilitation treatment indicated in the intervention scheme. Missing up to 5 sessions is allowed, and lost sessions will be possibly recovered at the end of treatment. In case of discontinuation of treatment (one or more sessions missed), the treatment will be restarted with the gait speed, trial duration, and level of difficulty used in the last completed session. Participants who will miss more than 5 sessions will be considered dropouts. Sample size. The G*Power software was used to estimate the sample size. From the literature, previous studies that aimed to evaluate the effects of treadmill training other than routine (partial weight-supported treadmill training) on patients with PD had observed a high effect size (ɳ2=0.737). In our estimate, a medium effect size (f=0.25) was conservatively chosen. Assuming a statistical power of 95% and an α=0.05, the resulting sample is 22 subjects per arm. To compensate for possible drop-outs, estimated at around 35%, the enrollment of a further 16 patients is appropriate, 8 per treatment arm, reaching an estimate of 30 subjects per group. Data analysis. For all data, the distribution will be assessed using the Kolmogorov-Smirnov test (assuming the presence of normal distribution when p>0.05). Data will then be summarised as mean and standard deviation, median and interquartile range, or absolute and percentage frequency, as appropriate. The two groups will be compared at baseline to explore significant differences in clinical and demographic variables. Both within- and between-groups analysis will be conducted to assess the effects of the treatments delivered, for both primary and secondary outcome measures. Specifically, a repeated measures ANOVA will be used with a within-factor (Time of assessment) and a between-factor (Group). Statistical analysis will be conducted using the software International Business Machines Corporation (IBM) Statistical Package for the Social Sciences (SPSS) v28. The acquired Raman spectra will be analyzed by multivariate Principal Component Analysis - Linear Discriminant Analysis (PCA-LDA) classification. PCA will reduce the number of variables into principal components, which will be used to build the LDA model. The model will be built to discriminate clinical improvement detected as quantifiable change on clinical scales, defined based on the minimum clinically important difference, when available from the literature. Sensitivity, specificity and accuracy of the predicting model based on spectra data will be assessed. In addition, correlation analysis will be conducted to evaluate the association between spectral data and change on clinical scales recorded between the beginning and the end of the treatment. Statistical analysis of the Raman data will be performed using Origin2021 software. Univariate analysis models will be applied to select the best prognostic markers of clinical improvement to be included in the multivariate model. For all analyses, statistical significance will be set at p<0.05

Parkinson Disease, Gait, Festinating, Fall Due to Loss of Equilibrium, Gait, Unsteady, Gait, Shuffling

Parkinson Disease, Gait rehabilitation, Balance, Falls, Physiotherapy, Rehabilitation, Biomarkers, Raman spectroscopy, extracellular vesicles

Outcome Assessors will be blinded regarding treatment assignment, including clinicians assessing the eligibility of patients and enrolling them in the study; the evaluators (neurologist, physiatrist, psychologist, physical therapists, engineers, laboratory staff). Blindness will be ensured by the modality and timing of assessments at T0, T1, and T2 that will be conducted at times other than treatment and by evaluators not involved in the treadmill training. Blinding will be removed if requested by the participant at the end of the study and in case of undesirable effects.

Participants (N=30) will undergo the AVR Treadmill training intervention with 5 AVR applications named "Nature Island", "stepping stones", "walking area": "obstacles avoidance", and "track".

The protocol will include three sessions per week for 8 weeks of gait training using C-Mill with AVR applications. An anchoring system will prevent possible falls, activities will be stopped on patient request, or when a heart rate considered safe will be exceeded. The patient will be supervised by a physical therapist and asked not to use lateral bars. Treatment is planned to be progressive and will be individualized to the participant's level of performance. Progression in gait speed: at the training start, gait speed will be set at 80% of the individual's overground walking speed and weekly increased by 10%, to a maximum of 120%; progression in trial duration: at the training start the duration will be set at 25' and every two weeks increased by 5'; the maximum duration of a session will reach 45'; progression in difficulty: the protocol has 5 levels for each AVR application, and the transition among levels will be set at 80% success achievement.

The protocol will include three sessions per week for 8 weeks of gait training using C-Mill without AVR applications, walking on the treadmill. An anchoring system will prevent possible falls, activities will be stopped on patient request, or when a heart rate considered safe will be exceeded. All sessions will be supervised by a physical therapist, who will give guidance and standardized cues on walking patterns (e.g., step length). The patient will be asked not to use the lateral bars. Treatment is planned to be progressive and will be individualized to the participant's level of performance: progression in gait speed: at the training start, gait speed will be set at 80% of the individual's overground walking speed and weekly increased by 10%, to a maximum of 120%; progression in trial duration: at the training start the duration will be set at 25' and every two weeks increased by 5'; the maximum duration of a session will reach 45'.

Mean change in gait and balance parameters assessed by the Performance Oriented Mobility Assessment - POMA scale (intra-group and between-group comparisons)

The POMA scale is an easily administered task-oriented test that measures an older adult's balance (9 items) and gait (7 items) abilities. Items are scored with a three-point (0-2) or a two points (0-1) scale, where "0" indicates the highest level of impairment and "2" - "1" for dichotomic items - the individual's independence. Total Balance Score = 16; Total Gait Score = 12.

Mean change in motors parameters assessed by the Modified Unified Parkinson's Disease Rating Scale (MDS-UPDRS), part III (intra-group and between-group comparisons)

The MDS-UPDRS part III includes 18 items concerning the motor examination in PD, evaluating different aspects: walking, balance, speech, bradykinesia, tremor, and rigidity. Each item is scored on a five-point ordinal rating scale, ranging from 0 to 4, where "0" indicates normal function and "4" is the highest level of impairment. Some items inclusive of evaluation of a symptom in different parts of the body, e.g on the right side, on the left side, upper and lower limbs). Score range 0-132.

The biological characterization of patients at T0 analyzing cEVs performed by Raman Spectroscopy will provide numerical scores that will be correlated with motor parameters obtained at T1 to identify predictive biomarkers of an outcome measure of rehabilitation

The Raman spectrum of blood-derived cEVs before and after treatment will be compared to identify spectral differences and to monitor the effect of rehabilitation on the spectral biomarker. Changes in the presence/absence of peaks and peaks intensity will be evaluated.

Gait speed (m/s) will be measured at both comfortable and maximum speeds using the Optogait system (http://www.optogait.com/Gait-Phases).

Right and left step length (m) will be measured at both comfortable and maximum speeds using the Optogait system (http://www.optogait.com/Gait-Phases).

Mean change in walking endurance assessed with the 6-Minutes Walking Test (6MWT) (intra-group and between-group comparisons).

The distance (m) walked in 6 minutes on a 30 meters walkway will be measured, indicating the greater distance, a better score

Mean change in gait adaptability assessed by C-Gait application of C-Mill (intra-group and between-group comparisons)

Walking-adaptability task performance was defined as the percentage of correctly performed steps relative to the projected visual objects in 6 different tasks. C-gait score for each task: Level×2×Performance (%) / 100. The overall assessment score was an average score based on average performance over the six walking-adaptability tasks at the higher level of difficulty, ranging from 0 (poor performance) to 8 (excellent performance).

Mean change in freezing during walking assessed by the Freezing Of Gait Questionnaire (FOG-Q) (intra-group and between-group comparisons).

The FOG-Q includes 6 items that inquires about the subject's experiences of freezing during the previous week. Each item use a five-points ordinal scale, ranging from "0" (= absence of symptoms) to "4" (= more severe disturbance). Total score ranges from 0 to 24, and higher scores correspond to more severe freezing.

Postural sway assessed with a dynamometric footplate (postural sway in quiet standing with opened/closed eyes). Lower postural sway corresponds to better stability.

Mean change in global cognitive functions assessed by the Montreal Cognitive Assessment (MoCA) (intra-group and between-group comparisons)

The MoCA test is used to assess global cognitive functions. A score superior to 18.58 is required for inclusion in the study (Aiello et al, 2021); parallel versions will be administered at different time points (Siciliano et al, 2019). Higher values correspond to better cognition, range of score 0-30.

Mean change in global cognitive functions assessed by the Parkinson's disease-cognitive rating scale, italian version (PD-CRS) (intra-group and between-group comparisons)

The PD-CRS is a suitable tool to assess cognition in PD, it evaluates different domains and permits to obtain a cortical and a subcortical score: sum of results in item 1,3,4,5,7,8,9 (range of score 0-104), represents the subcortical score; sum of results in item 2 and 6 (range of score 0-30), represents the cortical score. Higher scores correspond to better cognition

Mean change in attention skills assessed by Trail Making Test A and B (TMTA and TMTB) (intra-group and between-group comparisons)

TMTA evaluates sustained attention and the visual search capacity, and TMTB evaluates divided attention. For both tests A and B time and errors will be registered. Slowness and more errors are indicative of lower performances (No range of score).

Mean change in executive functions as assessed by the Stroop Test (intra-group and between-group comparisons)

The Stroop test is used to assess executive functions (time and error interference effect). Slowness and higher interference effect indicative of lower performances. (No range of score).

Mean change in executive functions as assessed by the Symbol Digit oral version (intra-group and between-group comparisons)

Digit symbol is used for the assessment of attention and working memory. Range of score 0-110. Higher score indicative of better performance

Mean change in functional mobility assessed by the Modified Parkinson Activity Scale (MPAS) (intra-group and between-group comparisons)

The MPAS scale evaluates motor skills in activities of daily living. Range of score 0-56; higher score indicative of better functional mobility.

Mean change in functional mobility assessed by the Timed up and go test (TUG) (intra-group and between-group comparisons)

The TUG is a general physical performance test used to assess mobility, balance, and gait during walking, turning, and sit-to-stand tasks. Time is recorded during the test; less time indicative of better performances (no range of score).

Mean change in functional autonomy assessed by the modified Barthel Index (mBI) (intra-group and between-group comparisons)

mBI is a scale for assessing functional independence in daily life. Range of score 0-100. Lower score corresponds to less independence.

Mean change in the quality of life assessed by the Parkinson's Disease Questionnaire Italian version (PDQ-39-IT) (intra-group and between-group comparisons)

PDQ-39 is a self-report questionnaire for assessing the quality of daily life in PD. It includes 39 items assessing how often persons experience difficulty across 8 quality of life dimensions. Each item is scored on a five-point ordinal scale from 0 (=never) to 4 (always). Each dimension total score ranges from 0 (never have difficulty) to 100 (always have difficulty). The summary total score is calculated as the mean of the 8 dimension total scores. A higher score corresponds to a lower quality of life.

Mean change in the fear to fall assessed by the Falls efficacy scale, Italian version (FES-I) (intra-group and between-group comparisons)

FES-I is used for the assessment of the fear-of-fall. It includes 16 items rated on a four-point scale from 1 (not confident at all) to 4 (completely confident). Total score ranges from minimum 16 (no concern about falling) to maximum 64 (severe concern about falling).

Mean change in mood assessed by the Beck Depression Inventory II, italian version (BDI) (intra-group and between-group comparisons)

BDI II is used for the assessment of mood and consists of 21 items, each of whom corresponding to a symptom of depression. Each item is scored on a scale of 0-3 in a list of four statements arranged in increasing severity. Total score ranges from 0 to 63; higher scores indicates more severe depression.

Mean change in pain perception assessed by the Numerical rating scale (NRS) (intra-group and between-group comparisons)

NRS is suitable for the assessment of current pain severity as perceived by the participant using a 0-10 points scale. A score of 10 corresponds to the worst pain.

Mean change in number and severity of falls assessed by the Falls Questionnaire (intra-group and between-groups comparisons)

Falls Questionnaire is used for the assessment of the frequency and severity of falls. It provides information on the modality of falls and the number of falls in the last 12 months. A superior number of falls suggests a lower balance (no range of score).

Perception of satisfaction to the treatment assessed with a subjective satisfaction questionnaire- 5 point Likert scale

Inclusion Criteria: Diagnosis of Parkinson's disease according to the diagnostic (POSTUMA criteria) Hoehn and Yahr Stage II-III Age>18 years One fall in the past 3 months/presence of postural instability /gait disturbance Able to walk for at least 5 minutes without assistance Stable drug therapy by at least 1 month Willingness to participate in the study, ability to understand and willingness to sign informed consent Exclusion Criteria: Other pathology concurrent with gait disturbance (symptomatic arthritis involving hip/knee/ankle, stroke outcomes, severe polyneuropathy) Cognitive impairment capable of interfering with rehabilitation procedures, estimated as a score less than 18.58 at the Montreal Cognitive Assessment (MoCA), row score corrected according to Aiello et al, 2022 Hallucinations Psychiatric disorder not controlled by current drug therapy Alcohol/drug use Uncompensated visual/auditory deficit that limits enjoyment of the cues provided by the AVR Communication deficit from any cause that impairs understanding of the task and the objectives of the intervention Recurrent episodes of severe orthostatic hypotension Severe cardiovascular diseases Patient undergoing other experimental protocol (patients regularly undergoing physical activity or sport will not be excluded)

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