Dual-Task Balance and Gait Training Combined With Cognitive Training in Parkinson's Patients

Parkinson's disease (PD) is the most common movement disorder and the second most prevalent neurodegenerative disease after Alzheimer's disease. In addition to cardinal motor symptoms such as bradykinesia, rigidity, and resting tremor, PD is associated with a wide spectrum of non-motor symptoms that substantially increase overall disease burden. Among these, cognitive impairment is particularly significant, occurring up to six times more frequently in individuals with PD compared to the healthy population.

Although research on cognition in PD has increased over the past two decades, knowledge and treatment strategies for cognitive deficits remain limited compared to those addressing motor symptoms. Since no effective treatment currently exists to prevent or delay cognitive decline in PD, investigations into cognitive interventions are gaining increasing importance for understanding and managing this disabling aspect of the disease, which may emerge at all stages.

One promising intervention is RehaCom, a computer-based program that provides personalized cognitive training modules tailored to individual needs. Previous studies have demonstrated that RehaCom improves cognitive performance, enhances quality of life, and optimizes function in impaired domains. By prioritizing learning principles and offering individualized training for specific cognitive dimensions, RehaCom has also been shown to promote neural plasticity in patients with PD.

Motor learning literature emphasizes that not only training intensity but also conditions resembling real-life scenarios are critical for effective rehabilitation. Daily activities often require walking and maintaining balance while simultaneously performing additional tasks, such as speaking (cognitive dual-task) or carrying an object (motor dual-task). Dual-task training, which integrates motor training with either a cognitive or an additional motor task, is a comprehensive approach supported by strong evidence. Compared to single-task practice, dual-task training enhances motor learning, yields greater functional gains, and facilitates transfer of these improvements to activities of daily living.

Considering the deficiencies in cognition as a reason for the progressive and irreversible nature of the pathogenesis of PD, the present study hypothesizes that providing structured cognitive skills training will be more effective in improving both motor and cognitive functions. However, a review of the literature indicates that studies in this area remain limited. Therefore, the present study aims to implement and evaluate a rehabilitation program combining cognitive training with dual-task-focused balance and gait exercises in individuals with PD.

The intervention will start with core stability training, followed by dual-task balance and gait training. After completion of the dual-task training phase, participants will undergo structured cognitive training.

Other: Core Stability Training · Other: Dual-Task Balance and Gait Training · Other: Cognitive Training

The intervention will start with core stability training, followed by dual-task balance and gait training.

Other: Core Stability Training · Other: Dual-Task Balance and Gait Training

Core stability training will be designed to prepare participants for subsequent balance and gait exercises by promoting normal proprioceptive input through activation of deep core muscles. This training will be performed in the supine position at the beginning of each session for both groups.

Dual-task balance and gait training will be provided with task-oriented motor-cognitive and motor-motor exercises with the augmented and virtual reality system C-Mill VR+ (Motek Medical, Amsterdam, The Netherlands). Sessions will be individualized based on each participant's current abilities and the difficulty level of the tasks to address specific patient needs. Each training session will have a duration of 30 minutes for both groups.

Cognitive training will be provided with RehaCom software, a program that emphasizes learning principles, provides task-specific exercises, delivers positive feedback, and allows individualized progression based on patient-specific difficulty levels. In the present study, the cognitive training will target the "Attention," "Memory," and "Executive Functions" domains, which are known to be affected from the early stages of Parkinson's disease. Exercises will be initiated at a level appropriate to each participant's cognitive abilities and will gradually increase in difficulty. Each training session will have a duration of 30 minutes.

Time frame: From enrollment to the end of the 6-Week training program

The static standing balance of participants will be assessed using the Huber 360° Evolution System (LPG Systems, Valence, France). The following measurements will be performed with this device:

Postural Stability Test: Postural stability will be evaluated in parallel feet (eyes open/closed) and single-leg positions. Each test will be repeated three times, with a 10-second rest interval between repetitions. The displacement area (mm²), and path length (mm) of the center of pressure will be recorded. Additionally, during the test, the displacement of the center of pressure per unit time will be recorded as velocity (mm/s).

Time frame: From enrollment to the end of the 6-Week training program

The dynamic standing balance of participants will be assessed using the Huber 360° Evolution System (LPG Systems, Valence, France). The following measurements will be performed with this device:

Limits of Stability Test: During the test, participants will be instructed to shift their weight toward eight different directions. Each test will be repeated three times, with a 10-second rest interval between repetitions. Outcome measures will include the displacement of the center of pressure in each direction (mm) and the sway area (mm²) resulting from the displacement of the center of pressure across all directions.

Time frame: From enrollment to the end of the 6-Week training program

The C-Mill VR+ system (Motek Medical, Amsterdam, The Netherlands) will be used for the evaluation. The analysis will include the recording of step length (mm), step width (mm) and stride length (mm).

Time frame: From enrollment to the end of the 6-Week training program

The C-Mill VR+ system (Motek Medical, Amsterdam, The Netherlands) will be used for the evaluation. The analysis will include the recording of stance phase duration (ms), swing phase duration (ms), and double support phase duration (ms).

Time frame: From enrollment to the end of the 6-Week training program

The C-Mill VR+ system (Motek Medical, Amsterdam, The Netherlands) will be used for the evaluation. The analysis will include the recording of walking distance (m) as a functional performance outcome.

Time frame: From enrollment to the end of the 6-Week training program

The C-Mill VR+ system (Motek Medical, Amsterdam, The Netherlands) will be used in the evaluation. The analysis will include recording the displacement of the individual per unit time on the running belt as gait speed (m/s).

Time frame: From enrollment to the end of the 6-Week training program

Montreal Cognitive Assessment (MoCA), which provides a general cognitive screening in different cognitive functions such as attention, concentration, executive functions, memory, language, visual structuring skills, abstract thought, calculation and orientation, will be used in the general evaluation of cognition. MoCA is an effective scale especially in the evaluation of mild cognitive impairments in Parkinson's disease (PD). The cut-off score range of MoCA has been shown to be 18-26 points in individuals with PD who has mild cognitive impairment. The administration of MoCA takes approximately 10 minutes. The highest total score that can be obtained from the test is 30. Accordingly, a score of 21 points and above is considered normal.

Time frame: From enrollment to the end of the 6-Week training program

In the comprehensive evaluation of cognition, specific evaluation will be made for the sub-domains of cognition which are "Attention", "Memory" and "Executive Functions" will be made using the screening modules of the RehaCom software. Before each evaluation, a practice mode will be applied in which the patient is informed about the things to be careful about during the evaluation, the expected task and the purpose of the evaluation. In all screening results, the z-values, mean of reaction time (ms), median of reaction time (ms), standard deviation of reaction time (ms) and correct, incorrect, error and skip numbers in the tests will be recorded as standardized data compared with the data of at least 200 age and gender matched healthy individuals in RehaCom's database.

Time frame: From enrollment to the end of the 6-Week training program

Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) consists of 4 parts, like the classic UPDRS. The severity of the patients' motor symptoms will be assessed using the Motor Examination part, which is the 3rd part of the MDS-UPDRS. MDS-UPDRS Part 3 consists of 18 items. All items in the scale are scored between 0 (Normal) and 4 (Severe) points.

Time frame: From enrollment to the end of the 6-Week training program

The level of confidence felt by the patient in daily life activities requiring balance skills will be evaluated with the Activities-Specific Balance Confidence (ABC) Scale. In this scale, individuals are asked to rate the sense of security they feel while performing 16 activities requiring balance skills between 0% and 100%.

Time frame: From enrollment to the end of the 6-Week training program

In addition to gait speed, the effect of dual-task on gait speed will be assessed by calculating the dual-task cost using the following formula:

\[(Dual Task Gait Speed-Single Task Gait Speed)/(Single Task Walking Speed)\] x 100%

Investigation of the Effects of Dual-Task Balance and Gait Training Combined With Cognitive Training in Parkinson's Patients