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

Abstract

Background Meta-analyses indicate positive effects of cognitive training (CT) in patients with Parkinson’s disease (PD), however, most previous studies had small sample sizes and did not evaluate long-term follow-up. Therefore, a multicenter randomized controlled, single-blinded trial (Train-ParC study) was conducted to examine CT effects in PD patients with mild cognitive impairment (PD-MCI). Immediately after CT, an enhancement of executive functions was demonstrated. Here, we present the long-term results 6 and 12 months after CT. Methods At baseline, 64 PD-MCI patients were randomized to a multidomain CT group (n = 33) or to a low-intensity physical activity training control group (PT) (n = 31). Both interventions included 90 min training sessions twice a week for 6 weeks. 54 patients completed the 6 months (CT: n = 28, PT: n = 26) and 49 patients the 12 months follow-up assessment (CT: n = 25, PT: n = 24). Primary study outcomes were memory and executive functioning composite scores. Mixed repeated measures ANOVAs, post-hoc t tests and multiple regression analyses were conducted. Results We found a significant time x group interaction effect for the memory composite score (p = 0.006, η2 = 0.214), but not for the executive composite score (p = 0.967, η2 = 0.002). Post-hoc t tests revealed significant verbal and nonverbal memory improvements from pre-intervention to 6 months, but not to 12 months follow-up assessment in the CT group. No significant predictors were found for predicting memory improvement after CT. Conclusions This study provides Class 1 evidence that multidomain CT enhances memory functioning in PD-MCI after 6 months but not after 12 months, whereas executive functioning did not change in the long-term. Clinical trial registration German Clinical Trials Register (ID: DRKS00010186), 21.3.2016 (The study registration is outlined as retrospective due to an administrative delay. The first patient was enrolled three months after the registration process was started. A formal confirmation of this process from the German Clinical Trials Register can be obtained from the authors.)

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

“…With regard to CT, we previously demonstrated improvement of executive function (EF) in PD-MCI induced by multi-domain group CT, specially showing an enhanced effect for patients that were more affected [ 4 ]. Likewise, such intervention was able to improve memory function after 6 months, although the improvement was not present after 12 months, while EF remained stable in the long term [ 5 ]. Notoriously, it has recently been reported that CT increases PA in patients with PD-MCI, possibly due to effects on EF [ 6 ].…”

“…Based on a multicenter (MC) study addressing the independent effect of CT and PA on cognition, we previously reported a statistical trend on the interaction between time and group (CT and PA) on overall EF and a significant effect only on phonemic fluency as a specific part of EF [ 4 ]. Moreover, we reported a significant effect on the interaction between time and group (CT and PA) on memory after 6 months of intervention, but not on EF after 6 and 12 months of intervention although EF enhancement occurred immediately after intervention [ 5 ]. Note that the MC study is slightly significant regarding the independent effect of interventions on EF, however the single center data that we consider in the present study showed no independent effect of interventions on EF, possibly due to underpower.…”

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

“…However, some reviews included non-randomized controlled trials (RCTs) or lacked quantitative analyses (Cusso et al, 2016;Triegaardt et al, 2020;Cartmill et al, 2021;Takamiya et al, 2021); thus, these systematic reviews did not provide strong evidence. In addition, most RCTs compared nonpharmacological interventions with placebo, waiting list, or usual treatments, and only a few RCTs compared two different non-pharmacological interventions (Modugno et al, 2010;Kalbe et al, 2020;Schmidt et al, 2021). To our knowledge, only one systematic review has reported the efficacy of nonpharmacological interventions on depression in PD subjects (Chen et al, 2021).…”

Cognitive Safety of Cannabis Products in Parkinson's Disease: Need for Solid Scientific Evidence to Guide Clinicians and Patients Currently on Shaky Grounds

“…Although there were no statistically significant differences on any of the individual cognitive tests, the authors found statistically significant improvement via practice effect was more common in the placebo than treatment group. A global statistical test with unweighted z-scores or non-parametric ranks 10,11 could be useful to answer the question of impact on cognition more broadly. This would also avoid challenges associated with controlling for Type-I error and provide a meaningful metric to associate with subjective cognitive symptom reporting.…”