Memory enhancement by multidomain group cognitive training in patients with Parkinson's disease and mild cognitive impairment: long-term effects of a multicenter randomized controlled trial

Associations between baseline cognitive status and motor outcomes after treadmill training in people with Parkinson's disease: a pilot study

PURPOSE

To determine the effect of baseline cognition on gait outcomes after a treadmill training program for people with Parkinson's disease (PD).

METHODS

This pilot clinical trial involved people with PD who were classified as having no cognitive impairment (PD-NCI) or mild cognitive impairment (PD-MCI). Baseline executive function and memory were assessed. The intervention was a 10-week gait training program (twice-weekly treadmill sessions), with structured speed and distance progression and verbal cues for gait quality. Response to intervention was assessed by gait speed measured after week 2 (short-term) and week 10 (long-term).

RESULTS

Participants (n = 19; 12 PD-NCI, 7 PD-MCI) had a mean (standard deviation) age of 66.5 (6.3) years, disease duration of 8.8 (6.3) years, and MDS-UPDRS III score of 21.3 (10.7). Gait speed increased at short-term and long-term assessments. The response did not differ between PD-NCI and PD-MCI groups; however, better baseline memory performance and milder PD motor severity were independently associated with greater improvements in gait speed in unadjusted and adjusted models.

CONCLUSIONS

These findings suggest that memory impairments and more severe motor involvement can influence the response to gait rehabilitation in PD and highlight the need for treatments optimized for people with greater cognitive and motor impairment.IMPLICATIONS FOR REHABILITATIONCognitive deficits in Parkinson's disease (PD) could impact motor learning and gait rehabilitation, yet little is known about the effects of cognitive impairments on the response to rehabilitation in people with PD.This study demonstrates that the response to gait rehabilitation did not differ between people with PD who had no cognitive impairment and those with mild cognitive impairment.Across all participants, better baseline memory was associated with greater improvements in gait speed.Rehabilitation professionals should be mindful of PD severity, as those with more substantial memory and motor impairments may require additional dosing or support to maximize gait training benefits.

Medical, surgical, and physical treatments for Parkinson's disease

Although dopamine replacement therapy remains a core component of Parkinson's disease treatment, the onset of motor fluctuations and dyskinetic movements might require a range of medical and surgical approaches from a multidisciplinary team, and important new approaches in the delivery of dopamine replacement are becoming available. The more challenging, wide range of non-motor symptoms can also have a major impact on the quality of life of a patient with Parkinson's disease, and requires careful multidisciplinary management using evidence-based knowledge, as well as appropriately tailored strategies according to the individual patient's needs. Disease-modifying therapies are urgently needed to prevent the development of the most disabling refractory symptoms, including gait and balance difficulties, cognitive impairment and dementia, and speech and swallowing impairments. In the third paper in this Series, we present the latest evidence supporting the optimal treatment of Parkinson's disease, and describe an expert approach to many aspects of treatment choice where an evidence base is insufficient.

Resting state EEG as biomarker of cognitive training and physical activity's joint effect in Parkinson's patients with mild cognitive impairment

BACKGROUND

Cognitive decline is a major factor for the deterioration of the quality of life in patients suffering from Parkinson's disease (PD). Recently, it was reported that cognitive training (CT) in PD patients with mild cognitive impairment (PD-MCI) led to an increase of physical activity (PA) accompanied by improved executive function (EF). Moreover, PA has been shown to alter positively brain function and cognitive abilities in PD. Both observations suggest an interaction between CT and PA.

OBJECTIVES

A previous multicenter (MC) study was slightly significant when considering independent effects of interventions (CT and PA) on EF. Here, we use MC constituent single center data that showed no effect of interventions on EF. Thus, this exploratory study considers pooling data from both interventions to gain insight into a recently reported interaction between CT and PA and provide a proof of principle for the usefulness of resting state EEG as a neurophysiological biomarker of joint intervention's effect on EF and attention in PD-MCI.

METHODS

Pre- and post-intervention resting state EEG and neuropsychological scores (EF and attention) were obtained from 19 PD-MCI patients (10 (CT) and 9 (PA)). We focused our EEG analysis on frontal cortical areas due to their relevance on cognitive function.

RESULTS

We found a significant joint effect of interventions on EF and a trend on attention, as well as trends for the negative correlation between attention and theta power (pre), the positive correlation between EF and alpha power (post) and a significant negative relationship between attention and theta power over time (post-pre).

CONCLUSIONS

Our results support the role of theta and alpha power at frontal areas as a biomarker for the therapeutic joint effect of interventions.

Multidomain cognitive training increases physical activity in people with Parkinson's disease with mild cognitive impairment

INTRODUCTION

Cognitive impairment in Parkinson's disease (PD), especially in patients with mild cognitive impairment (PD-MCI), coincides with less physical activity. Cognitive trainings (CT) have been found to promote laboratory environment-based movement. Knowledge about their effect in natural home-based environment, reflecting everyday function, is sparse. This explorative study investigated short-term effects of CT on physical activity assessed by home-based accelerometry, and its relation to change of cognitive function over time and non-cognitive outcomes in patients with PD-MCI. Cognitive and non-cognitive correlates of movement parameters at pretest were evaluated as well.

METHODS

Eighteen patients with PD-MCI of the TrainParC study were analyzed. Those patients received either a 6-week multidomain group CT or physical training (PT). Physical activity and sedentary behavior were assessed with wearable accelerometers worn up to seven days pre- and post-training.

RESULTS

Patients in the CT group displayed significantly greater increases in active periods after training than patients assigned to PT. In the CT group, increases in executive functioning were associated with increases in active periods and decreases in active mean bout length after training. At pretest, reduced working memory correlated with longer sedentary mean bout length, and impairment in activities of daily living (ADL) correlated with a higher number of sedentary periods.

CONCLUSION

Study data revealed that CT can increase physical activity in patients with PD-MCI, possibly due to effects on executive functions, which needs further investigation in larger sample sizes. Lower working memory performance and ADL impairment might be associated with a more inactive lifestyle in patients with PD-MCI.

Exercise for Depressive Symptoms in Parkinson Disease: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

To evaluate the efficacy of physical exercise in improving depressive symptoms in Parkinson disease (PD).

DATA SOURCE AND STUDY SELECTION

We conducted a systematic review of randomized controlled trials (RCTs) following a prespecified protocol guidance (PROSPERO CRD42021243142). Two independent authors searched for studies in MEDLINE, Cochrane Register of Controlled Trials, Physiotherapy Evidence Database, Embase, PsycINFO, and Sports Discus from database inception to June 2022.

DATA EXTRACTION

Two independent authors extracted the data and evaluated the risk of bias using the revised Cochrane risk of bias tool. We performed random-effects meta-analyses and rated the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

DATA SYNTHESIS

A total of 36 RCTs met the inclusion criteria, 14 of which were pooled in the quantitative synthesis. Depression symptomatology significantly decreased in the exercise group compared with usual care (standardized mean difference [SMD], -0.49; 95% confidence interval [CI], -0.74 to -0.24; very low quality of evidence; 14 RCTs; 961 participants). Physical exercise also improved patients' quality of life (SMD, -0.51; 95% CI, -0.81 to -0.21; 7 RCTs; 485 participants). As for acceptability, we did not find any difference between exercise and usual care (relative risk, 1.01; 95% CI, 0.97 to 1.05; 12 RCTs; 1048 participants). We judged all the studies except 2 to be at high risk of bias.

CONCLUSIONS

Results from our systematic review identify physical activity as a viable option to reduce depressive symptoms in PD. Future clinical practice guidelines should consider physical exercise in their recommendations for depression symptomatology reduction in people with PD.

Efficacy of non-pharmacological interventions for depression in individuals with Parkinson's disease: A systematic review and network meta-analysis

BACKGROUND

Depression in Parkinson's disease (PD) is a major health concern worldwide. Recently, an increasing number of non-pharmacological interventions have been used in PD to alleviate depressive symptoms. However, it is uncertain which intervention is the best, and related evidence is limited. This network meta-analysis was performed to compare and rank non-pharmacological interventions for PD and analyze their effects on depression to provide evidence for clinicians to choose appropriate non-pharmacological management options.

METHODS

The PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), PsycINFO, China National Knowledge Infrastructure (CNKI), and Wanfang databases were searched from inception to April 7, 2022. Two authors screened all studies, extracted the data, and evaluated the methodological quality. STATA software version 16.0 was used to conduct the network meta-analysis.

RESULTS

Our network meta-analysis included 62 studies involving 3,050 participants and 35 non-pharmacological interventions. Although most non-pharmacological interventions showed non-significant effects, the surface under the cumulative ranking curve (SUCRA) values indicated that the best non-pharmacological intervention for depression was dance (82.3%), followed by LSVT-BIG therapy (77.4%), and CBT (73.6%).

CONCLUSION

Dance can be considered as an effective therapy for improving depression in patients with PD. In the future, more strictly designed trials are needed to verify the conclusions of this network meta-analysis.

Consolidation and reconsolidation of visual and semantic memory in Parkinson’s disease

Cognitive and mnestic impairments have a significant negative impact on the quality of parkinsonian patients’ life. Memory impairment causes changes in the mechanisms of information processing. The aim of this study was to investigate the characteristics of transformations undergone by memorized visual and semantic content during memory consolidation and reconsolidation in patients with Parkinson’s disease. The study was conducted on 32 male patients with PD (ICD code: G20). Among the patients, 9 had rigidity/bradykinesia-d ominant PD, 11 had tremor-dominant PD, and 12 suffered from a mixed type of PD. Short-term memory span was assessed using the 10 words and the visual memory tests proposed by Luria. As stimulus materials we used a symbolic representation of the old Greek letter resembling an owl and a translated excerpt from a Canadian aboriginal epic. Regardless of the PD form, the quality of the memorized information was either altered or completely lost. The mechanisms underlying such transformations differed quantitively depending on the PD form. Transformation of the memorized information occurred in the conditions of both incidental and deliberate memorization and was represented by distortions (substitution of the original content with confabulations) and simplifications of the structural and semantic organization. We consolidated significantly lesser amount of auditory verbal (р = 0.018) and visual (p = 0.029) information. This trend was consistent with the pronounced distortion of content during its retrieval.