Enhancement of Executive Functions but Not Memory by Multidomain Group Cognitive Training in Patients with Parkinson’s Disease and Mild Cognitive Impairment: A Multicenter Randomized Controlled Trial

Abstract

Background. Meta-analyses have demonstrated cognitive training (CT) benefits in Parkinson’s disease (PD) patients. However, the patients’ cognitive status has only rarely been based on established criteria. Also, prediction analyses of CT success have only sparsely been conducted. Objective. To determine CT effects in PD patients with mild cognitive impairment (PD-MCI) on cognitive and noncognitive outcomes compared to an active control group (CG) and to analyze CT success predictors. Methods. Sixty-four PD-MCI patients (age: 67.61 ± 7.70; UPDRS-III: 26.58 ± 13.54; MoCA: 24.47 ± 2.78) were randomized to either a CT group or a low-intensity physical activity CG for six weeks (twice weekly, 90 minutes). Outcomes were assessed before and after training. MANOVAs with follow-up ANOVAs and multiple regression analyses were computed. Results. Both interventions were highly feasible (participation, motivation, and evaluation); the overall dropout rate was 4.7%. Time × group interaction effects favoring CT were observed for phonemic fluency as a specific executive test ( p = 0.018 , η p 2 = 0.092 ) and a statistical trend for overall executive functions ( p = 0.095 , η p 2 = 0.132 ). A statistical trend for a time × group interaction effect favoring CG was shown for the digit span backward as a working memory test ( p = 0.098 , η p 2 = 0.043 ). Regression analyses revealed cognitive baseline levels, education, levodopa equivalent daily dose, motor scores, and ApoE status as significant predictors for CT success. Conclusions. CT is a safe and feasible therapy option in PD-MCI, yielding executive functions improvement. Data indicate that vulnerable individuals may show the largest cognitive gains. Longitudinal studies are required to determine whether CT may also attenuate cognitive decline in the long term. This trial is registered with DRKS00010186.

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

“…Following studies with healthy older adults and PD-MCI patients [ 42 – 49 ], we included as predictors the baseline level of the respective outcome variable, age, sex, education level, and ApoE4 status. Regarding PD characteristics, we added UPDRS III and levodopa equivalent daily dose (LEDD) as possible predictors what is in line with Kalbe et al [ 15 ].…”

“…Data monitoring was carried out by two members of another study site. For a detailed reporting on study design, randomization procedure and data management following the CONSORT statement, please see Kalbe et al [ 15 ].…”

“…As part of CT and PT, patients were encouraged to stimulate themselves cognitively and physically after the end of the training phase, but no new training sessions or exercises were conducted until the follow-up assessments. For further details of the study interventions, we refer to Supplementary Table 1 in the article by Kalbe et al [ 15 ].…”

“…Our recently published multicenter randomized controlled trial (RCT) that is directly linked to the present study analyzed the short-term results of CT in PD-MCI patients compared to an active physical training control group (PT) [ 15 ]. In the CT group, an enhancement of executive functions (especially verbal fluency) and self-reported physical activity could be demonstrated while working memory improved in the PT group.…”

Screen Fast, Screen Faster: A Pilot Study to Screen for Depressive Symptoms Using the Beck Depression Inventory Fast Screen in Parkinson's Disease With Mild Cognitive Impairment

“…Furthermore, patients were also classified according to the stages of PD by Hoehn and Yahr ( 19 ). For detailed information regarding the main study please refer to Kalbe et al ( 20 ).…”