Caring for a loved one with Parkinson's disease: the role of coping styles and relationship quality.

OBJECTIVE: Informal carers play an essential role in the care of individuals with Parkinson's disease (PD). This role, however, is often fraught with difficulties, including emotional, physical, and financial. Coping styles and relationship quality have been hypothesized to influence the impact of stressors. The aim of this study is to examine the relationship between carers' coping style, relationship quality, and carer burden. DESIGN: Cross-sectional. PARTICIPANTS: Thirty-nine PD patient carer dyads were included in the study. MEASUREMENTS: Participants completed self-rated questionnaires including the Dyadic Adjustment Scale, Zarit Burden Interview, and Brief Coping Orientation to Problems Experienced Inventory. RESULTS: Correlational analyses found significant and positive correlation between carer burden and all three coping styles (problem-focused, emotion-focused, and dysfunctional). There was also a moderate association between carers' perceived relationship quality and satisfaction and carer burden. Regression analyses found that carer's gender, severity of PD, relationship quality, emotion-focused, and dysfunctional coping styles did not predict carer burden. Conversely, problem-focused coping style predicted carer burden. CONCLUSION: The results highlight that there is no perfect way to react and care for a loved one and serves as important information for practitioners who design and implement interventions.

Hippocampal correlates of episodic memory in Parkinson's disease: A systematic review of magnetic resonance imaging studies.

The present review asks whether magnetic resonance imaging (MRI) studies are able to define neural correlates of episodic memory within the hippocampus in Parkinson's disease (PD). Systematic searches were performed in PubMed, Web of Science, Medline, CINAHL, and EMBASE using search terms related to structural and functional MRI (fMRI), the hippocampus, episodic memory, and PD. Risk of bias was assessed for each study using the Newtown-Ottawa Scale. Thirty-nine studies met inclusion criteria; eight fMRI, seven diffusion MRI (dMRI), and 24 structural MRI (14 exploring whole hippocampus and 10 exploring hippocampal subfields). Critical analysis of the literature revealed mixed evidence from functional and dMRI, but stronger evidence from sMRI of the hippocampus as a biomarker for episodic memory impairment in PD. Hippocampal subfield studies most often implicated CA1, CA3/4, and subiculum volume in episodic memory and cognitive decline in PD. Despite differences in imaging methodology, study design, and sample characteristics, MRI studies have helped elucidate an important neural correlate of episodic memory impairment in PD with both clinical and theoretical implications. Natural progression of this work encourages future research on hippocampal subfield function as a potential biomarker of, or therapeutic target for, episodic memory dysfunction in PD.

Anxiety disorders are associated with verbal memory impairment in patients with Parkinson's disease without dementia.

INTRODUCTION: Preliminary evidence has demonstrated a link between anxiety and memory impairment in Parkinson's disease (PD). This study further investigated this association using the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria for anxiety disorders and a standardized cognitive test battery. METHODS: A convenience sample of 89 PD patients without dementia was recruited from neurology outpatient clinics. A cross-sectional design was applied. Participants completed two semi-structured interviews. The first interview diagnosed DSM-5 anxiety disorders, unspecified anxiety disorder, and no anxiety. The second interview applied a neurocognitive test battery comprising two tests for each domain. Logistic regression models compared cognitive characteristics associated with anxiety disorders to no anxiety. RESULTS: Clinically significant anxiety was associated with immediate verbal memory impairment compared to the no anxiety group (OR, 95% CI 0.52, 0.30-0.89; p = 0.018), controlling for sex and age. The anxiety disorders group demonstrated immediate (OR, 95% CI 0.46, 0.26-0.83; p = 0.010) and delayed (OR, 95% CI 0.63, 0.40-0.99; p = 0.047) verbal memory impairments compared to those without anxiety, controlling for sex and age. This association remained for immediate (OR, 95% CI 0.43, 0.22-0.84; p = 0.013), but not delayed verbal memory impairment (OR, 95% CI 0.65, 0.39-1.06; p = 0.081) when additionally controlling for disease severity, education and levodopa dose. CONCLUSION: These findings present first evidence that anxiety disorders are associated with verbal memory impairment in PD and have implications for the management and treatment of anxiety in PD.

Identifying subtypes of mild cognitive impairment in Parkinson's disease using cluster analysis.

INTRODUCTION: The concept of Mild Cognitive Impairment (MCI) in Parkinson's disease (PD) has shown the potential for identifying at-risk dementia patients. Identifying subtypes of MCI is likely to assist therapeutic discoveries and better clinical management of patients with PD (PWP). Recent cluster-based approaches have demonstrated dominance in memory and executive impairment in PD. The present study will further explore the role of memory and executive impairment and associated clinical features in non-demented PWP. METHOD: A K-means cluster analysis was performed on ten "frontal" and "posterior" cognitive variables derived from a dataset of 85 non-demented PWP. The resulting cluster structure was chosen based on quantitative, qualitative, theoretical, and clinical validity. Cluster profiles were then created through statistical analysis of cognitive and clinical/demographic variables. A descriptive analysis of each cluster's performance on a comprehensive PD-MCI diagnostic battery was also explored. RESULTS: The resulting cluster structure revealed four distinct cognitive phenotypes: (1) frontal-dominant impairment; (2) posterior-cortical-dominant impairment; (3) global impairment, and (4) cognitively intact. Demographic profiling revealed significant differences in the age, gender split, global cognitive ability, and motor symptoms between these clusters. However, there were no significant differences between the clusters on measures of depression, apathy, and anxiety. CONCLUSION: These results validate the existence of distinct cognitive phenotypes within PD-MCI and encourage future research into their clinical trajectory and neuroimaging correlates.