Cognitive Training in Parkinson’s Disease: A Review of Studies from 2000 to 2014

Abstract

Cognitive deficits are prevalent among patients with Parkinson's disease (PD), in both early and late stages of the disease. These deficits are associated with lower quality of life, loss of independence, and institutionalization. To date, there is no effective pharmacological treatment for the range of cognitive impairments presented in PD. Cognitive training (CT) has been explored as an alternative approach to remediating cognition in PD. In this review we present a detailed summary of 13 studies of CT that have been conducted between 2000 and 2014 and a critical examination of the evidence for the effectiveness and applicability of CT in PD. Although the evidence shows that CT leads to short-term, moderate improvements in some cognitive functions, methodological inconsistencies weaken these results. We discuss several key limitations of the literature to date, propose methods of addressing these questions, and outline the future directions that studies of CT in PD should pursue. Studies need to provide more detail about the cognitive profile of participants, include larger sample sizes, be hypothesis driven, and be clearer about the training interventions and the outcome measures.

Evaluating a frontostriatal working-memory updating-training paradigm in Parkinson’s disease: the iPARK trial, a double-blinded randomized controlled trial

“…Recent studies have also shown that PD complicated by cognitive dysfunction confers a shorter life expectance compared to PD with normal cognitive function [52]. The demand for nonpharmacological interventions is increasing and there is, although modest, growing evidence of the benefit of cognitive interventions in PD [20][21][22]24]. While some studies have shown the efficacy of cognitive interventions in persons with PD, studies on newly diagnosed patients, excluding those with severe cognitive decline, are sparse.…”

“…This patient group is already burdened by polypharmacy and therefore investigating nonpharmacological treatment options is crucial [19]. Recent systematic reviews on cognitive training in PD have shown evidence of improvements in overall cognition as well as in working memory, processing speed, and executive functions [20][21][22][23][24]. Most studies have had a broad cognitive approach [25][26][27] making it hard to know what aspects of training that is causing the improvement.…”

“…Baseline factors such as cognitive functioning, stage of PD, premorbid intelligence can have contributing effects on individual differences in training gain. Therefore, future studies need to include more participants, be theory-driven, and include more details of the cognitive profile, training intervention, and outcome measures [21].…”

Comparison of cognitive profile in young- and late-onset parkinson's disease patients

“…However, because of the inconsistencies in the training interventions and outcome measures, the authors emphasized on conducting large, well-designed studies in future. [ 17 ]…”

Cistanche extracts ameliorates the neurotoxicity induced by hydrogen peroxide in new mutant DJ‐1‐transfected neuroblastoma cellular models

“…Among these disorders, the incidence rate of PD is second in the world and achieves to 1%–2% in the people over 60 years old (Burke & O'Malley, ; Mullard, ; Shen & Ji, ). As the major neurological characteristics of PD, the dopaminergic neurons in the substantia nigra pars compacta is progressive degenerative (Glizer & MacDonald, ), which is accompanied by the appearance of α‐synuclein inclusions called Lewy bodies (Zhang, An, Zhang, & Pu, ). In the pathogenesis of PD, rest tremors, rigidity, bradykinesia, and postural abnormalities are be diagnosed as main symptoms of PD in clinic.…”