Effect of Motor Learning Feedback on Cognitive Functions in Parkinsonism

Abstract

Parkinson’s disease is characterized by cognitive impairments that impair motor control. The major goal was to see how motor learning feedback with enhanced motor learning cues affected cognitive skills in Parkinson’s patients. This study engaged the participation of 30 patients of both genders. The patients were split into two equal groups at random: The participants in the study were given motor learning feedback along with augmented motor learning cues and the selected cognitive therapy program, while the control group received only the selected cognitive therapy program. The patients were assessed by the computer-based cognitive assessment device (Reha-Com) and the Mini-Mental State Examination (MMSE) scale. The study’s findings revealed a significant difference between the study and control groups (p = 0.0001), The study group exhibited a larger improvement in cognitive functioning than the control group. In Parkinson’s patients, motor learning feedback with enhanced cues has a significant beneficial effect on cognitive skills.

1. Introduction

Parkinson’s disease (PD) is characterized by deficits in cognitive functions and motor control, such as difficulties in movement initiation, scaling movement amplitudes, or modulating muscle activity. The basal ganglia, particularly those involved for “automatic execution of learnt motor plans,” play an important role in the generation and monitoring of motor programmes. The basal ganglia signal the end of a preparatory activation or a previous sub-movement in the supplementary motor area (SMA) to allow a new component of a movement sequence to be initiated. However, a compensatory cortical reorganization can be achieved by modulating cortical plasticity through peripheral feedback and sensorimotor integration [1].

Motor learning is a set of processes associated with practice or experience, leading to relatively permanent changes in the capability for movement. Motor learning involves three main stages, during the first or cognitive stage of learning, the performer engages in receiving instructions and feedback from the instructor, figuring out what to do and how to do it. The second, or associative, stage of learning is indicated by linking certain environmental cues with the actions necessary to attain the goal or skill, since this is a refining stage in which the person makes fewer errors and displays more task consistency. The third stage is called the autonomous stage as the automaticity is reached, where the performers no longer think about the specific movement characteristics and can often do another task at the same time [2].

“The mental action or process of obtaining information and understanding via thinking, experience, and the senses” is what cognition is defined as. Knowledge, attention, memory, and working memory, judgment and assessment, reasoning and “computation,” problem-solving, and decision-making are all included [3].

The executive functions are the most damaged by PD, resulting in a phenomenology similar to that of frontal lobe patients, with attention, planning, idea generation, and working memory deficits. Memory loss affects both spatial and non-spatial working memory domains, implicit memory, episodic memory, and procedural learning in particular, whereas the ability to construct new episodic memories is intact [4].

Visual perception and object identification problems are typically described as one of the first symptoms in people with Parkinson’s disease, and they appear to be unrelated to the degree of motor dysfunctions, neuropsychiatric comorbidities, and general cognitive decline. Cognitive symptoms may be connected to the subsequent involvement of other brain areas, such as the prefrontal cortex, hippocampus, and amygdala, in addition to the loss of dopaminergic neurons in the substantia nigra [5].

Executive dysfunction is the most frequent cognitive deficit in Parkinson’s disease, and it can affect planning, cognitive flexibility, abstract thinking, rule acquisition, working memory, and sensory input selection [6].

Feedback is a significant factor in motor skill acquisition. There are two forms of feedback in general. One type is sensory-perceptual information known as “task-intrinsic” (or inherent) feedback. The second type of feedback is known as “augmented” feedback, and it consists of (information, extrinsic, visual display of movement kinematics or kinetics or artificial feedback) [7].

The cueing methods such as (auditory and visual) cues are commonly applied to evoke a more goal-directed type of motor learning and reduce cognitive dysfunction severity in PD. When motor learning is coupled with external stimuli, which may become entrenched in or part of the central motor representation, at least in the near term, motor learning may be stronger (or performance increases may be greater) in people with Parkinson’s disease. As a result, cue-augmented learning may only be demonstrated in situations where cues are available and allowed to the learned motor abilities. This learning’s specificity has clear clinical consequences [8].

Some individuals with mental and perceptual deficits are unable to direct their performance via internal feedback. Additionally, they may be more dependent on augmented input since neurological sensory abnormalities may decrease their capacity to provide intrinsic feedback [8]. Improving task-intrinsic feedback with external cues to replace necessary internal inputs from the basal ganglia to enhance cognition and postural control during movement onset, completion, and boost task execution is known as using augmented cues [1]. It facilitates the accomplishment of the objective more rapidly, enhances one’s belief in one’s own expertise (motivation), and increases the likelihood that the activities will be repeated (reinforcement) [9].

So, this study was done to investigate the effect of motor learning stages combined with augmented cued of motor learning on cognitive functions in Parkinson’s patients.

2. Materials and methods

2.1 Assessment methods

All the patients were evaluated pre and post-treatment program, as the assessment methods were:

2.2 Assessment of cognitive function by Reha-com device

The computerized Reha-Com device including the (reaction behavior) program was used as the patient was instructed to deal and reacted with the different items shown on the computer screen in front of him. The Reaction Behavior program included a task in which the patient was asked to press the corresponding reaction button as fast as possible whenever a relevant stimulus - a traffic sign - was shown on the screen, in addition, there were also irrelevant signs which the patient must not react to. The task contains different (16) levels of difficulty.

2.3 Mini: mental state examination (MMSE) scale

It is a series of questions and tests, each of which scores points if answered correctly. If every answer is correct, a maximum score of (30) points is possible. The MMSE a number of different mental abilities, including a person’s memory, attention and language.

It is the most commonly used instrument for screening cognitive function, and can be used to indicate the presence of cognitive impairment, such as in a patient with Parkinsonism.

It includes questions that measured cognitive function including orientation, registration, attention and calculation, recall, and language. The maximum score is (30) points [10].

2.4 Intervention methods

The study group of the present study received both the functional task training using augmented cues of motor learning and a selected cognitive therapy program.

The Parkinson’s patients performed a functional task training program inform of Sit to stand task, which was divided into the following subtasks: sit-to-stand initiation (leaning forward); push up off the chair, and stand up fully. This program was performed according to the three- stages motor learning strategy as the first cognitive stage at the beginning of the session where the therapist provides the patients with illustrated details on subtasks performance via verbal instructions and visual feedback cues through observing the therapist’s performance, then the second associative stage which started as the patient performed the subtasks while receiving both tactile and verbal feedback cues from the therapist to detect error and correct it, finally, the third autonomous stage started as the therapist allowed the patient to perform the subtasks without the external feedback cues to be able to detect error and correct it by himself.

The control group received only the selected cognitive therapy program including the Compensatory complex task training through the step Square-Stepping Exercise (SSE): which is a simple foot placement pattern that involves forward, backward, lateral, and diagonal steps using a gridded floor squares, SSE is a physical exercise which also requires cognitive function by including intellectual activities such as attention, concentration, memory and imitation [11].

As the therapist demonstrated and performed a stepping pattern for the patient by stepping the feet on certain squares from a standing position, then the patient was asked to step on the floor squares in the same pattern that the therapist performed. Every patient in both groups received (three sessions) per week, for six weeks every other day for 60 minutes/session.

3. Results

3.1 Comparison between the results of both groups of cognitive reaction behavior level (RB) of the Reha com pre and post-intervention

• Pre-treatment: The mean ± SD level RB of the study group was 7 ± 1.73 and that of the control group was 7.33 ± 1.54. The mean difference between both groups was −0.33. There was no significant difference in the level of RB between the study and control groups (p = 0.58).

• Post-treatment: The mean ± SD level RB of the study group was 13 ± 2.2 and that of the control group was 9 ± 1.92. The mean difference between both groups was 4. There was a significant increase in the level RB of in the study group compared with that of the control groups (p = 0.0001) (Table 1).

RB Level	Pre-treatment		Post-treatment
	Study group	Control group	Study group	Control group
$\overline{\mathrm{{\rm X}}}$	7	7.33	13	9
SD	1.73	1.54	2.2	1.92
MD	−0.33		4
t-value	−0.55		5.29
p-value	0.58		0.0001***
Level of significance	NS		S

Table 1.

Pre and post-treatment mean values of RB level between both groups.

$\overline{\mathrm{{\rm X}}}$: Mean; MD: Mean difference; p-value: Probability value; S: Significant; SD: Standard deviation; t value: Unpaired t value; NS: Non-significant; ***: High Significance.

3.2 Comparison between mean values of both groups pre & post-treatment of mini-mental state examination (MMSE) scale of cognitive functions

• Pre-treatment: The mean ± SD MMSE of the study group was 11.8 ± 1.69 points and that of the control group was 11.93 ± 2.54 points. The mean difference between both groups was −0.13 points. There was no significant difference in the MMSE between both groups pre-treatment (p = 0.86).

• Post-treatment: The mean ± SD MMSE post-treatment of the study group was 23.06 ± 0.96 points and that of the control group was 17.26 ± 2.15 points. The mean difference between both groups was 5.8 points. There was a significant increase in the MMSE of the study group compared with that of the control groups post-treatment (p = 0.0001) (Table 2).

MMSE (points)	Pre-treatment		Post-treatment
	Study group	Control group	Study group	Control group
$\overline{\mathrm{{\rm X}}}$	11.8	11.93	23.06	17.26
SD	1.69	2.54	0.96	2.15
MD	−0.13		5.8
t-value	−0.16		9.52
p-value	0.86		0.0001***
Level of significance	NS		S

Table 2.

Pre and post-treatment mean values of MMSE between both groups.

$\overline{\mathrm{{\rm X}}}$: Mean; MD: Mean difference; p-value: Probability value; SD: Standard deviation; t value: Unpaired t value; NS: Non-significant; S: Significant.

4. Discussion

This study showed that the augmented cues of motor learning were more effective for improving cognitive dysfunction in Parkinson’s patients in the study group than only the selected cognitive therapy program. The findings of the present study were supported by Heremans et al., [12] who found that Visual-motor learning cues dramatically improved the cognitive and bradykinesia symptoms of Parkinson’s patients while reducing their bradykinesia. Heremans et al. [12] also showed that The participants’ mental state was greatly enhanced by the visual signals, and the PD patients, who consistently performed more slowly than controls, had a greater temporal isochrony with physical execution. The precision and timing of imagined motor activities were shown to be greatly improved by the addition of enhanced external stimuli.

Cued motor development Cueing has historically been thought of as a compensatory rehabilitation technique to increase motor output by evading the PD internal motor generating system’s deficiencies. Studies supporting the presence of an unique medial and lateral system with varied anatomical connections and functional relevance provide the basis of this bypassing idea. The basal ganglia and the supplementary motor area (SMA) in the medial system, along with intention and an individual’s internal reference frame, would assist the creation of actions [9].

The findings of the present study were also in agreement with Price and Shin [13] who reported that Parkinson’s patients with moderate cognitive impairment and those who demonstrate learning in the cognitive training program benefitted greatly from the use of enhanced feedback cues in these programs. Four weeks later, the experimental group’s MMSE scores greatly outperformed those of the control group (p < 0.05). Especially, the improvement was significant in the moderate cognitive impairment group (MMSE = 11 ∼ 21) (p < 0.05). In learned patients of the experimental group, the score of the MMSE was significantly more improved than the control group (p < 0.05).

Internal cueing processes are compromised in PD, resulting in symptoms like hypokinesia. However, by utilizing cerebral resources, external signals can enhance movement execution. Feedback signals sent by cerebro-cerebellar-cerebral neural networks can bypass damaged BG, improving the ability to move in response to the stimuli and raising cortical activity [12].

Several treatments for Parkinson’s physiotherapy therapies try to instruct patients on compensating attentional/cognitive techniques that may rely on the activation of alternate motor pathways. Indeed, it has been shown that both attentional strategies, such as instructions that rely on cognitive mechanisms of motor control and are internally generated, and augmented feedback cueing strategies (based on the use of external stimuli associated with the initiation and facilitation of a motor activity), can improve performance by using alternative pathways unaffected by Parkinson disease (PD) [14].

Bypassing the ineffective medial motor system, which includes the BG, cuing activates the lateral cortical system. In order to fix their internal image of the training action, patients can learn to use signals to “Consciously focus to faulty features of the imagined movement.” External cuing enhances the quality of motor imagery in PD. If this is the case, then cueing patients while they are using mental images can help them learn the task more quickly, enhancing function of that object [12].

Cueing training involves compensatory mechanisms since it is believed that externally induced movements bypass the compromised basal ganglia circuitry and instead stimulate the premotor cortex, cerebellum, and parietal cortex; and cueing training’s learning-related increases in motor performance are expected to be accompanied by neural changes. Cueing training in (PD) may have rapid impacts on compensatory neural pathways that are not directly used during routine activity. The conditions for goal-based exercise training are made easier by external cueing [15].

Doyon et al. [8] stated that Improvement in motor learning may be more pronounced in Parkinson’s disease (PD) (or performance gains may be stronger) when it gets coupled with external cues, which may also contribute to improvement in cognitive functioning, which, at least temporarily, may be incorporated into or made a part of the core motor image. As a result, cue-augmented learning may only be demonstrated in situations where cues are available and allow for online access to the learned motor abilities. In Parkinson’s patients who also have cognitive impairment, this specificity of learning has clear clinical consequences. The explanation provided by the author backs up the findings of the current investigation.

5. Conclusion

Based on the scope and findings of this study, which concluded that the rehabilitation program that depends on the motor learning stages and included the augmented cues of motor learning showed a significant improvement in Parkinson’s cognitive dysfunction, compared to the control group who received only the selected cognitive therapy program. Therefore, motor learning with augmented cues should be considered a potential rehabilitation program and must be indicated as an effective, reliable, noninvasive modality at physical therapy clinics for Parkinson’s patients with cognitive dysfunctions.

Conflict of interest

The authors declare no conflict of interest.