Altered Theory of Mind in Parkinson's Disease and Impact on Caregivers: A Pilot Study.

Mild cognitive impairment (MCI) in Parkinson's disease (PD) includes deficits in theory of mind (ToM). However, associations between ToM and caregiver burden and distress are still unclear. The objective of this pilot study was to preliminarily explore the relation between ToM and caregiver burden and distress in a sample of PD-MCI patients. Twelve PD-MCI patients were evaluated on a ToM task (Faux Pas), whereas their caregivers were assessed on caregiver burden (Zarit Burden Interview-12 items) and distress (Neuropsychiatric Inventory-Distress). Cognitive ToM was significantly associated with caregiver distress, but caregiver burden was associated with the severity of patient psychiatric symptoms.

Goal management training ® home-based approach for mild cognitive impairment in Parkinson's disease: a multiple baseline case report.

Approximately 30% of patients with Parkinson's disease experience mild cognitive impairment (PD-MCI), often affecting executive functions. Our objective was to assess tolerability, safety and preliminarily efficacy of Goal Management Training® (GMT) for PD-MCI. GMT was administered at home, for five weeks. Dysexecutive Questionnaire (DEX), Parkinson Disease Questionnaire (PDQ-39), Zoo Map Test and Dementia Rating Scale-II were administered before, one and four weeks after Adapted-GMT. Reliable Change Index (RCI) was calculated. One participant completed GMT with caregiver. Executive complaints decreased (DEX RCIs between -2.10 and -1.68), PDQ-39 was maintained (RCI = -0.18). Adapted-GMT seems safe for PD-MCI, but efficacy remains doubtful.

The influence of vascular risk factors on cognitive function in early Parkinson's disease.

OBJECTIVES: Hypertension, dyslipidemia, diabetes, and obesity are well-established risk factors for cognitive impairment and dementia in older adults. In contrast, previous studies that have assessed the impact of vascular risk factors (VRFs) on cognition in Parkinson's disease (PD) have had methodological limitations and reported conflicting findings. We address this question in a large well-characterized cohort of de novo PD patients. METHODS: A total of 367 untreated and non-demented patients aged 50 years and older with early PD (H&Y = 1.0-2.0) underwent a comprehensive clinical and neuropsychological assessment at baseline and 24 months later. A series of linear mixed models were used to determine the effects of VRFs on cognition while controlling for patient and disease characteristics. The outcomes included norm-referenced Z-scores of global cognition, visuospatial skills, verbal episodic memory, semantic verbal fluency, attention, and working memory tests. RESULTS: A longer history of hypertension and a higher pulse pressure were significant predictors of lower Z-scores on immediate and delayed free recall, recognition, and verbal fluency tests. On average, every 10 mmHg increase in pulse pressure was associated with a 0.08 reduction on the cognitive Z-scores. The effects were independent of age, education, disease duration, motor impairment, medication, and depressive symptoms. Other VRFs were not associated with cognitive outcomes. CONCLUSIONS: Our results are consistent with previous studies suggesting that hypertension exerts a detrimental effect on memory and verbal fluency in early PD. Management of blood pressure and cardiovascular health may be important to reduce risk of cognitive decline in PD. Copyright © 2017 John Wiley & Sons, Ltd.

Effects of Antiparkinson Medication on Cognition in Parkinson's Disease: A Systematic Review.

OBJECTIVE: This study aimed to systematically review the effects of currently prescribed antiparkinson medication on cognition in patients with mild-to-moderate Parkinson's disease (PD) who were either cognitively intact or mildly impaired. METHODS: English- and French-language studies published between 1969 and 2017 were accessed via MedLine, PsychNET, EMBASE and EBSCO databases. Methodological quality (MQ) was evaluated with the quality assessment instrument of the Cochrane Collaboration Depression, Anxiety and Neurosis Review (scores from 0% to 44% indicate very low quality; scores from 45% to 64% indicate low quality; scores from 65% to 84% indicate medium quality; and scores from 85% to 100% indicate high quality). Hedges' g and Student's t-test were performed on all cognitive outcome measures reported. RESULTS: In total, 14 studies assessed the cognitive effects of levodopa (L-D), pramipexole (PRX), selegiline (SEL) and rasagiline (RAS) in mild-to-moderate non-demented PD patients. The MQ was overall low, with an average score of 49.1%. Results for L-D showed deleterious effects on a test of cognitive inhibition, as well as benefits on tests of attention/processing speed/working memory, executive functions and episodic memory. Pramipexole was associated with a worsening of episodic memory and impulse control. Results on SEL indicated a deterioration of global cognition over time and of concept formation. Rasagiline had some benefits on working memory and verbal fluency. CONCLUSION: Antiparkinson medications can have deleterious (L-D; PRX; SEL) and beneficial (L-D; RAS) effects on cognition. However, randomized double-blind placebo-controlled trials with larger sample sizes are required to better elucidate this issue.

Smoking history is associated to cognitive impairment in Parkinson's disease.

INTRODUCTION: Patients with Parkinson's disease (PD) are more likely to suffer from cognitive impairment and dementia than healthy older adults. The aim of this study was to investigate smoking history as a risk factor for cognitive decline in PD. METHOD: One hundred thirty-nine PD patients aged 50 years and older (Hoehn and Yahr = 1-3) were recruited from a clinical database. Global cognitive function was assessed with the Mini-Mental State Examination (MMSE) and smoking history was investigated as part of a standard clinical interview. A multiple linear regression analysis was used to develop a model for predicting participants' MMSE scores from age, education, Hoehn and Yahr stage, disease duration, the number of vascular risk factors and the number of smoking pack-years. RESULTS: The regression model significantly accounted for 22.9% of the variance in MMSE scores. Significant predictors were education (ß = .312, p < .001), age (ß = -.215, p = .013) and total smoking pack-years (ß = -.180, p = .029). In former smokers, the number of years since quitting had no effect on global cognition and there were no significant difference between patients who had quit smoking more than 10 years ago and those who had quit less than 10 years ago, F(1, 63) = 1.72, p = .195. CONCLUSION: Smoking history was associated to global cognitive impairment in PD even in patients who had quit smoking. These results are in line with findings in healthy older adults that have linked smoking to cognitive impairment, global brain atrophy and functional changes. Future studies should consider a broader assessment of cognitive functions.

Impact of a cognitive rehabilitation intervention on neuropsychiatric symptoms in mild to moderate Alzheimer's disease.

The main goal of this study was to evaluate the impact of a cognitive rehabilitation programme on 12 behavioural and psychological symptoms of dementia (BPSD) in patients with mild to moderate Alzheimer's disease (AD). This six-month single-blind block-randomised cross-over controlled study was conducted with 15 mild to moderate AD participants and their caregivers. All participants received a four-week home-based cognitive rehabilitation programme to learn/re-learn an instrumental activity of daily living. They were assessed up until three months following the end of the intervention. The Neuropsychiatric Inventory (NPI-12) was employed to evaluate patients' BPSD at seven assessment points during the course of the study. A general linear mixed model analysis performed on the NPI data revealed that aberrant motor behaviours (AMB) increased significantly more in the treatment condition than in the control condition. In addition, both groups registered a significant reduction of delusional symptoms during the second half of the study. Employing a multi-symptom approach to assess participants' BPSD, this cross-over randomised controlled study showed that an individualised cognitive rehabilitation intervention was generally well-tolerated by mild to moderate AD patients. Future cognitive rehabilitation studies conducted with this population should pay attention to AMB symptom changes.

A randomized cross-over controlled study on cognitive rehabilitation of instrumental activities of daily living in Alzheimer disease.

OBJECTIVE: The goal of the study was to investigate the effectiveness of a memory rehabilitation program to re-learn instrumental activities of daily living (IADLs) in patients with Alzheimer disease (AD). DESIGN: This was a 6-month block-randomized cross-over controlled study. SETTING: All evaluation and training sessions were performed at each patient's home. PARTICIPANTS: Twenty participants with mild to moderate AD. INTERVENTION: The trained IADL was chosen by the patient and his/her caregiver in order to target the patient's needs and interests. Participants were trained twice a week for 4 weeks with the errorless learning (ELL) and spaced retrieval (SR) cognitive techniques. After training, there were several follow-ups over a period of at least 3 months. MEASUREMENTS: Performance on the trained IADL was assessed by a Direct Measure of Training (DMT), an observational instrument adapted from a well-validated scale. General cognitive function, everyday memory functioning, quality of life, neuropsychiatric symptoms and ADL/IADL of patients, as well as the caregiver's burden were assessed as secondary outcomes. RESULTS: A statistical significant difference was found between the trained and untrained groups on the DMT immediately following the intervention. Improvements were maintained for a 3-month period. The training did not have effects on any other measures. CONCLUSIONS: The present study showed that it is possible for AD patients to relearn significant IADLs with the ELL and SR techniques and to maintain these gains during at least 3 months. The findings of this study emphasize the importance to design robust but individualized intervention tailored on patients' particular needs.

Clinical validity of the Mattis Dementia Rating Scale-2 in Parkinson disease with MCI and dementia.

The utility of the Mattis Dementia Rating Scale 2 (MDRS-2) in screening for dementia in Parkinson disease (PD) is well documented. However, little is known about its sensitivity to mild cognitive impairment in PD (PD-MCI). This study sought to document the validity of the MDRS-2 for diagnoses of PD-MCI and dementia in PD (PDD). Twenty-two healthy controls (HCs), 22 PD-MCI, and 16 PDD were compared on each MDRS-2 subscales and MDRS-2 total standard scores. Patients with PDD performed significantly worse than the other groups (all Ps < .05) on the MDRS-2 total and on all subscales, except attention. PD-MCI had significant lower scores than HCs on the MDRS-2 total and on initiation/perseveration and memory subscales. The optimal cutoff score for PD-MCI diagnosis was ≤ 140/144 and ≤ 132/144 for PDD. These findings suggest that MDRS-2 is a useful tool to identify dementia but that there might be a ceiling effect in the MDRS-2 cutoff score to diagnose MCI in PD.

[Pathological gambling in patients with Parkinson disease]. / Jeu pathologique chez les patients atteints de la maladie de Parkinson.

Pathological gambling implies an inadequate, persistent and chronic practice of gambling which has major impact on affected individuals, their families and the society (APA, 2003). Many risk factors of social, psychological and biological nature contribute to the development of pathological gambling. New populations have been found to be at risk to develop pathological gambling : patients who suffer of Parkinson Disease's. Development of pathological gambling in those patients would mainly be related to the medication used to treat Parkinson Disease's, dopaminergic agonist. Numerous neurological studies have been conducted on the subject since recent years, but few psychologists know this problem and almost no studies have been made to understand the psychological aspect of this problem.

Goal management training and psychoeducation / mindfulness for treatment of executive dysfunction in Parkinson's disease: A feasibility pilot trial.

INTRODUCTION: As there is currently no pharmacological treatment for Parkinson's Disease Mild Cognitive Impairment (PD-MCI) with executive dysfunctions, specific cognitive interventions must be investigated. Most previous studies have tested bottom-up cognitive training programs but have not shown very good results. OBJECTIVES: The aim of this study was to test ease of implementation, differential safety and preliminary efficacy of two top-down (strategy-learning) home-based, individualized, cognitive interventions: Goal Management Training (GMT), adapted for PD-MCI (Adapted-GMT), and a psychoeducation program combined with mindfulness exercises (PSYCH-Mind). METHODS: This was a single-blind block-randomized between-group comparative study. Twelve PD-MCI with mild executive dysfunctions were divided in four blocks and randomly assigned to any of the two interventions. The participants were included if they had PD-MCI diagnosis (no dementia), with stabilized medication. Both groups (Adapted-GMT and PSYCH-mind) received five intervention sessions each lasting 60-90 minutes for five weeks. Measures were collected at baseline, mid-point, one-week, four-week and 12-week follow-ups. Executive functions were assessed with the Dysexecutive questionnaire (DEX) and the Zoo Map Test (ZMT). Quality of life (QoL) and psychiatric symptoms were also evaluated. Repeated measures ANCOVAs (mixed linear analysis) were applied to all outcomes. RESULTS: There was one drop out, and both interventions were feasible and acceptable. Despite the small sample size limiting statistical power, patients of both groups significantly improved executive functions per the DEX-patient (Time: F(4,36) = 2.96, p = 0.033, CI95%: 10.75-15.23) and DEX-caregiver scores (Time: F(4,36) = 6.02, p = 0.017, CI95%: 9.63-17.23). Both groups significantly made fewer errors between measurement times on the ZMT (Time: F(3,36) = 16.66, p = 0.001, CI95%: 1.07-2.93). However, QoL significantly increased only in PSYCH-Mind patients at four-week follow-up (interaction Time*Group: F(4,36) = 5.31, p = 0.002, CI95%: 15.33-25.61). CONCLUSION: Both interventions were easily implemented and proved to be safe. Because both interventions are arguably cost-effective, these pilot findings, although promising, need to be replicated in large samples. CLINICALTRIALS.GOV IDENTIFIER: NCT04636541.

Methodological considerations when establishing reliable and valid normative data: Canadian Longitudinal Study on Aging (CLSA) neuropsychological battery.

Objective: Creation of normative data with regression corrections for demographic covariates reduces risk of small cell sizes compared with traditional normative approaches. We explored whether methods of correcting for demographic covariates (e.g., full regression models versus hybrid models with stratification and regression) and choice of covariates (i.e., correcting for age with or without sex and/or education correction) impacted reliability and validity of normative data. Method: Measurement invariance for sex and education was explored in a brief telephone-administered cognitive battery from the Canadian Longitudinal Study on Aging (CLSA; after excluding persons with neurological conditions N = 12,350 responded in English and N = 1,760 in French). Results: Measurement invariance was supported in hybrid normative models where different age-based regression models were created for groups based on sex and education level. Measurement invariance was not supported in full regression models where age, sex, and education were simultaneous predictors. Evidence for reliability was demonstrated by precision defined as the 95% inter-percentile range of the 5th percentile. Precision was higher for full regression models than for hybrid models but with negligible differences in precision for the larger English sample. Conclusions: We present normative data for a remotely administered brief neuropsychological battery that best mitigates measurement bias and are precise. In the smaller French speaking sample, only one model reduced measurement bias, but its estimates were less precise, underscoring the need for large sample sizes when creating normative data. The resulting normative data are appended in a syntax file.

Late-onset-psychosis: cognition.

BACKGROUND: The objectives of the study were to characterize and compare the cognitive profile and natural evolution of patients presenting late-onset psychotic symptoms (LOPS: onset ≥ 50 years old) to those of elderly patients (≥ 50 years old) with life-long/early-onset schizophrenia (EOS: onset <40 years old). METHODS: Neuropsychological profiles of 15 LOPS patients were compared to those of 17 elderly EOS patients and to those of two control groups (n = 11/group). The evolution of the two patient groups was compared using an independent diagnostic consensual procedure involving a geriatric psychiatry physician/clinician and a neuropsychologist blinded to the initial psychiatric diagnosis. RESULTS: EOS presented significant memory and executive impairments when compared to controls but there was no significant difference between LOPS and their controls when age and education were taken into account. However, a detailed inspection of normative data suggests more executive impairments in LOPS than in EOS. The clinical judgment of experts was in favour of significant cognitive deficits with or without dementia in most LOPS (82.3%-94.1%) and EOS (80.0%-93.3%) patients. Regarding evolution, mild cognitive impairment (MCI) and vascular cognitive impairment (VCI) were the most common clinical diagnoses made by geriatric psychiatry physicians/clinicians for the LOPS (40%). In addition, 20% of LOPS versus 5.9% of EOS patients met the diagnostic criteria for dementia by consensus of the experts. Cerebral abnormalities were confirmed (CT scan; SPECT) in 73.3% of LOPS patients. CONCLUSION: The present results suggest cognitive deficits (mostly of executive functions) and vascular and neurodegenerative vulnerability in LOPS. Further studies with larger samples are needed to confirm the present findings.

Telephone administration of the Mental Alternation Test: sensitivity to cognitive decline and practice effects across midlife and late life.

BACKGROUND: We evaluated the utility of the telephone-administered Mental Alternation Test (MAT, an oral variant of the Trail-Making Test) for remote assessment of cognitive functioning in older adults. We examined (1) the sensitivity of MAT scores to cognitive change across 4 age groups, (2) practice effects associated with repeat administration, and (3) the uniformity of practice effects across age groups. METHODS: Community-dwelling volunteers were recruited randomly and categorized as young-middle-aged (45-54 years; n = 51), middle-aged (55-64 years; n = 58), young-old (65-74 years; n = 43) or old-old (75-85 years; n = 43). The participants completed the MAT twice within 2 weeks. The data were analyzed using mixed ANOVA. RESULTS: We found an effect of age on MAT performance [F(3, 191) = 11.37; p < 0.001], with planned comparisons revealing significantly lower scores in the old-old (p < 0.05). The scores on the second MAT administration were significantly higher than on the first administration [F(1, 191) = 12.82; p < 0.001], but this practice effect did not differ across age groups. CONCLUSIONS: The MAT was sensitive to cognitive decline in older adulthood. Practice effects were measurable but uniform across the observed age cohorts. As a brief telephone-administered test, the MAT represents a promising measure of cognitive functioning in older adults that is feasible for use in large-scale epidemiological studies.

Cognitive intervention programs for individuals with mild cognitive impairment: systematic review of the literature.

This systematic literature review addressed the efficacy of 15 cognitive intervention programs that have been tested in individuals presenting with mild cognitive impairment of the amnestic type (MCI-A) possibly at risk to progress toward dementia. MEDLINE, PsycINFO, and Current Content databases were searched using the following key terms: cognitive training, cognitive stimulation, cognitive rehabilitation, neuropsychological intervention, memory training, memory stimulation, and Mild Cognitive Impairment. The data showed statistically significant improvements at the end of training on 44% of objective measures of memory, when compared with 12% of objective measures of cognition other than memory. Statistically significant improvements after treatment were obtained on 49% of subjective measures of memory, quality of life, or mood. Samples sizes ranged from 1 to 193 patients with MCI-A but were usually < or =30. Five studies were randomized controlled trials, eight were quasiexperimental designs, and two were single-case investigations. Some programs focused only on memory, whereas other programs used multifaceted approaches targeting two or more cognitive functions. Eight were offered in groups, and seven took place on an individual basis. Recommendations to improve cognitive interventions in MCI-A are proposed, such as using large samples and a robust experimental design, as well as the implementation of a standardized cognitive training manual. Well standardized and validated direct and indirect measures of efficacy and noncognitive outcomes are also a crucial issue. A consensus meeting among all the experts working on cognitive training in this population should occur to provide guidelines to improve this treatment option.

Efficacy of a cognitive training programme for mild cognitive impairment: results of a randomised controlled study.

This study aimed to determine the efficacy of cognitive training in a 10-week randomised controlled study involving 22 individuals presenting with mild cognitive impairment of the amnestic type (MCI-A). Participants in the experimental group (n = 11) learned face-name associations using a paradigm combining errorless (EL) learning and spaced retrieval (SR) whereas participants in the control group (n = 11) were trained using an errorful (EF) learning paradigm. Psycho-educational sessions on memory were also provided to all participants. After neuropsychological screening and baseline evaluations, the cognitive training took place in 6 sessions over a 3-week period. The post-training and follow-up evaluations, at one and four weeks respectively, were performed by research assistants blind to the participant's study group. The results showed that regardless of the training condition, all participants improved their capacity to learn face-name associations. A significant amelioration was also observed in participant satisfaction regarding their memory functioning and in the frequency with which the participants used strategies to support memory functions in daily life. The absence of difference between groups on all variables might be partly explained by the high variability of scores within the experimental group. Other studies are needed in order to verify the efficacy of EL learning and SR over EF in MCI-A.

The Canadian longitudinal study on aging as a platform for exploring cognition in an aging population.

Objective: We present descriptive information on the cognitive measures used in the Canadian Longitudinal Study on Aging (CLSA) Comprehensive Cohort, relate this to information on these measures in the extant literature, and identify key considerations for their use in research and clinical practice.Method: The CLSA Comprehensive Cohort is composed of 30,097 participants aged 45-85 years at baseline who provided a broad range of sociodemographic, physical, social, and psychological health information via questionnaire and took part in detailed physical and cognitive assessments. Cognitive measures included: the Rey Auditory Verbal Learning Test - immediate and 5-min delayed recall, Animal Fluency, Mental Alternation Test (MAT), Controlled Oral Word Association Test (COWAT), Stroop Test - Victoria Version, Miami Prospective Memory Test (MPMT), and a Choice Reaction Time (CRT) task.Results: CLSA Comprehensive Cohort sample sizes were far larger than previous studies, and performances on the cognitive measures were similar to comparable groups. Within the CLSA Comprehensive Cohort, main effects of age were observed for all cognitive measures, and main effects of language were observed for all measures except the CRT. Interaction effects (language × age) were observed for the MAT, MPMT Event-based score, all time scores on the Stroop Test, and most COWAT scores. Main effects of education were observed for all measures except for the MPMT Time score in the French sample, and interaction effects (age × education) were observed for the RAVLT (immediate and delayed) for the English sample and the Stroop Dot time for the French sample.Conclusion: This examination of the cognitive measures used in the CLSA Comprehensive Cohort lends support to their use in large studies of health and aging. We propose further exploration of the cognitive measures within the CLSA to make this information relevant to and available for clinical practice.

Partial measurement equivalence of French and English versions of the Canadian Study of Health and Aging neuropsychological battery.

Neuropsychological batteries are often translated for use across populations differing in preferred language. Yet, equivalence in construct measurement across groups cannot be assumed. To address this issue, we examined data from the Canadian Study of Health and Aging, a large study of older adults. We tested the hypothesis that the latent variables underlying the neuropsychological battery administered in French or English were the same (invariant). The best-fitting baseline model, established in the English-speaking Exploratory sample (n = 716), replicated well in the English-speaking Validation sample (n = 715), and the French-speaking sample (FS, n = 446). Across the English- and FSs, two of the factors, Long-term Retrieval and Visuospatial speed, displayed invariance, that is, reflected the same constructs measured in the same scales. In contrast, the Verbal Ability factor showed only partial invariance, reflecting differences in the relative difficulty of some tests of language functions. This empirical demonstration of partial measurement invariance lends support to the continued use of these translated measures in clinical and research contexts and illustrates a framework for detailed evaluation of the generality of models of cognition and psychopathology, across groups of any sort.

Vascular risk factors and cognitive functions in nondemented elderly individuals.

BACKGROUND: The brain-at-risk stage is the earliest phase of the vascular cognitive impairment continuum and includes individuals with vascular risk factors (VRF). However, there is still no clear definition of this concept. The aim of the study is to characterize the neuropsychological profile of elderly individuals by 3 levels of VRF. METHODS: This is a cross-sectional analysis of the Canadian Study of Health and Aging baseline data; 577 nondemented elderly individuals > or =65 years old were divided into 3 groups: reference group (0 VRF; n = 82); intermediate brain-at-risk group (1-2 VRF; n = 360); high brain-at-risk group (> or =3 VRF; n = 135). A principal component analysis (PCA) and univariate/multivariate analyses of variance were performed to examine the relationships between the groups and various cognitive measures. MAIN FINDINGS: The PCA produced a 2-component solution (1) executive/psychomotor functions including measures of abstraction and (2) verbal memory. The high brain-at-risk group performed significantly worse than the reference group on the first component. CONCLUSIONS: Elderly individuals presenting with > or =3 VRF are more impaired on measures of executive functions/ processing speed than participants without any VRF.

Psychological distress and risk for dementia.

The concept of mild cognitive impairment (MCI) primarily emphasizes changes in individuals' mental abilities, but it has recently been suggested that neuropsychiatric symptoms should also be considered important factors in age-related neurodegeneration. Psychological distress, defined as a reaction of an individual to external and internal stresses, is characterized by a mixture of psychological symptoms. It also may be considered a neuropsychiatric symptom encompassing depression, anxiety, and apathy. This paper reviews and summarizes recent evidence and relevant issues regarding the presence of psychological distress in healthy older adults and MCI patients and its relationship to risk for developing dementia. Results presented in this review show that psychological distress and depressive, anxious, and apathetic symptoms can be present in MCI and may predict progression to dementia. This article also provides suggestions for future research.

The impact of cognitive interventions on cognitive symptoms in idiopathic Parkinson's disease: a systematic review.

This systematic review addressed efficacy of cognitive stimulation (CS), cognitive training (CT), and cognitive rehabilitation (CR) to improve cognitive functions in Parkinson's disease (PD) with (PD-MCI) and without mild cognitive impairment (PD-H). Five databases were searched. Twelve CT, four CS, and a combination of CT with CR were found. PD-H benefited from CT or CS compared to active or passive controls in 42.1% of cognitive tests, and in 33.3% of psychological and functional measures. PD-MCI alone, compared with controls, only improved in 6.9% of cognitive measures after CT. PD-H and PD-MCI, alone or together, somehow improved information processing speed, attention, working memory, executive functions, and visual episodic memory. PD-MCI improved better than PD-H in global cognition and planning abilities. The outcomes suggest some efficacy of cognitive interventions in PD. However, small samples, lack of information regarding standardization of interventions, and poor methodological quality limit results validity and prevent firm conclusions.