Cognitive impairment in Parkinson's disease: impact on quality of life of carers

Filling the gap in service provision. Partners as family carers to people with Parkinson's disease: A Scandinavian perspective

OBJECTIVES

The purpose of this study was to explore the expectations of and experiences with the public healthcare system of domestic partners of people with Parkinson`s disease (PD) in Denmark and Norway.

METHODS

A qualitative exploratory design was applied. The sample consisted of 14 people from Denmark (n = 9) and Norway (n = 5) living with a partner with PD. Semi-structured individual interviews were conducted between June and September 2020, digitally recorded, transcribed verbatim and analysed using a reflexive thematic analysis approach combining inductive and deductive approaches.

RESULTS

The main themes were 'negotiating systems of support' and 'balancing being both a partner and a family carer'. Partners take responsibility for the people with whom they live and attempt to fill gaps in the public healthcare system. The most frequently described needs were more information, service coordination as the illness progressed and acknowledgement of the complex role.

DISCUSSION

A recommendation for practice is recognition of the complex roles of partners to people with PD and reaching out to both regularly to determine needs. This may enhance the collaboration between partner carers, people with PD and healthcare providers, ensure sustainability of the system and optimise living with PD in the family.

Cognitive function in different motor subtypes of Parkinson's disease: A systematic review protocol

Background and Aims

As the fastest-growing neurological disorder globally, a better understanding of Parkinson's disease (PD) is needed to improve patient outcomes and reduce the increasing economic and healthcare burden associated with the disease. Whilst classified as a movement disorder, this disease is highly heterogeneous, encompassing a broad range of both motor and non-motor symptoms (NMS). Cognitive impairment, presenting as either mild cognitive impairment or PD-dementia, is one of the most prevalent and disabling NMS. To better understand heterogeneity in PD, researchers have sought to identify subtypes of individuals who share similar symptom profiles. To date, this research has predominantly focused on motor subtyping, with many studies comparing these motor subtypes on non-motor outcomes, such as cognitive impairment. However, despite evidence of a motor-cognitive relationship in healthy aging, findings regarding the presence of a motor-cognitive relationship in PD are inconsistent. In our proposed systematic review, we will investigate motor subtyping studies that have evaluated the relationship between motor and cognitive function in PD. We aim to examine what is currently known about the relationship between motor and cognitive impairment in PD and evaluate the state of the field with respect to the subtyping methods and quality of cognitive assessment tools used.

Methods

Systematic literature searches will be conducted in PubMed, PsycINFO, CINAHL, Scopus, and Web of Science.

Results

Results will be synthesized using meta-analysis and, where meta-analysis is not feasible, narrative synthesis.

Conclusion

Despite the preponderance of motor subtyping research in PD, our study will be the first to systematically review evidence regarding the association between motor subtypes and cognitive impairment. Understanding the nature of the motor-cognitive relationship in PD may lead to important insights regarding shared underlying disease pathology, which would have significant implications for early diagnosis, prognosis, and treatment of cognitive impairment in PD.

Validation of the Italian version of the Parkinson's Disease- Cognitive Functional Rating Scale

A key distinguishing factor between mild cognitive impairment (MCI) and dementia in Parkinson's disease (PD) lies in the notable decrease in functioning due to cognitive impairment. The Parkinson's Disease-Cognitive Functional Rating Scale (PD-CRFS) was developed to assess functional limitations caused by cognitive impairment, while reducing the influence of motor impairment. The aim of this multicenter study was to (i) validate the Italian version of the PD-CFRS in PD, (ii) determine optimal cut-off scores for detecting MCI and dementia in PD, (iii) compare its performances with the most established functional assessment tool (IADL). Six hundred and sixty nine PD participants were recruited from 4 Italian Movement Disorders centers (Venice, Milan, Gravedona, and Salerno). They underwent Level-II cognitive evaluation, which resulted in 282 PD-NC, 310 PD-MCI, and 77 PDD. The PD-CFRS's psychometric and clinimetric properties, applicability, and responsiveness were analyzed. The PD-CFRS showed high acceptability. Floor and ceiling effects were acceptable. It also displayed strong internal consistency (Cronbach's α = 0.738), and test-retest reliability (ICC = .854). The PD-CFRS demonstrated higher coefficient of variation to detect dysfunction in PD-MCI patients in comparison to the IADL scale (PD-CFRS 96% vs IADL 22.5%). Convergent validity with the IADL was r = - 0.638 and - 0.527 in males and females, respectively. PD-CFRS total score negatively correlated with global cognition (MoCA corrected score r = - 0.61; p < 0.001). A cut-off score > 6.5 identified PDD with a sensitivity of 90% and specificity of 88% (AUC = .959). A cut-off value of > 1 detected PD-MCI with a sensitivity of 68% and specificity of 69% (AUC = .695). The Italian version of the PD-CFRS demonstrated to be an easy, valid and reliable tool that properly captures functional impairment due to cognitive decline in PD. It also proved to be particularly effective in the advanced stages of PD, and would be a useful support for the diagnosis of PD-MCI and PDD.

[The role of the neuropsychologist in Parkinson's disease]

Psychologists specializing in neuropsychology, more commonly known as neuropsychologists, play an important role in the care of cognitive, behavioral and emotional aspects of patients with Parkinson's disease. They are also involved in research and public education on the disease.

Caregiver Burden in Parkinson Disease: A Scoping Review of the Literature from 2017-2022

Caregiver burden is a term that refers to the adverse effect of caregiving on the physical, emotional, social, spiritual, and financial well-being of the caregiver. Caregiver burden is associated with providing care to an individual with a chronic illness or disability, and the unique symptoms of Parkinson disease (PD) can amplify a patient's needs and reliance on others, leading to adverse outcomes for patients and their caregivers. In this scoping review of the literature from January 2017 through April 2022 that included 114 studies, we provide an updated, evidence-based summary of patient and caregiver-related factors that contribute to caregiver burden in PD. We also describe the impact of caregiver stress and burden on caregivers based on qualitative research studies and review recent interventions to mitigate burden. By providing clinical updates for practitioners, this review is designed to improve recognition of caregiver burden in the post-pandemic era and foster the development of targeted interventions to reduce caregiver burden in PD.

Learned Irrelevance, Perseveration, and Cognitive Aging: A Cross-Sectional Study of Cognitively Unimpaired Older Adults

The effect of natural aging on physiologic mechanisms that regulate attentional set-shifting represents an area of high interest in the study of cognitive function. In visual discrimination learning, reward contingency changes in categorization tasks impact individual performance, which is constrained by attention-shifting costs. Perseveration (PE) and learned irrelevance (LI) are viewed as two different mechanisms that shape responses to stimuli, which are predicated on the shift in stimulus form. To date, only studies examining patients with Parkinson’s disease have provided some insight into the relationship between individual age and performance in PE and LI tasks. We enrolled 60 healthy individuals (mean [SD] age, 63.0 [12.6]) without a history of dementia, a cerebrovascular incident, or a neurodegenerative disease. No association was observed between crystallized intelligence or verbal fluency scores and reaction time in both PE (r = 0.074, p = 0.603; r = −0.124, p = 0.346) and LI (r = −0.076, p = 0.562; r = −0.081, p = 0.536) task conditions, respectively. In contrast, a statistically significant linear relationship was observed between age and reaction time (RT) for PE (r = 0.259, p = 0.046) but not for LI (r = 0.226, p = 0.083). No significant linear relationship was observed for changing RTs in PE and LI (r = 0.209, p = 0.110). The present study is the first report that provides a descriptive overview of age-related differences in PE and LI in a sample of cognitively unimpaired middle- to older-aged adults.

Integrin Mac1 mediates paraquat and maneb-induced learning and memory impairments in mice through NADPH oxidase-NLRP3 inflammasome axis-dependent microglial activation

INTRODUCTION

The mechanisms of cognitive impairments in Parkinson's disease (PD) remain unknown. Accumulating evidence revealed that brain neuroinflammatory response mediated by microglial cells contributes to cognitive deficits in neuropathological conditions and macrophage antigen complex-1 (Mac1) is a key factor in controlling microglial activation.

OBJECTIVES

To explore whether Mac1-mediated microglial activation participates in cognitive dysfunction in PD using paraquat and maneb-generated mouse PD model.

METHODS

Cognitive performance was measured in wild type and Mac1^-/- mice using Morris water maze test. The role and mechanisms of NADPH oxidase (NOX)-NLRP3 inflammasome axis in Mac1-mediated microglial dysfunction, neuronal damage, synaptic degeneration and phosphorylation (Ser129) of α-synuclein were explored by immunohistochemistry, Western blot and RT-PCR.

RESULTS

Genetic deletion of Mac1 significantly ameliorated learning and memory impairments, neuronal damage, synaptic loss and α-synuclein phosphorylation (Ser129) caused by paraquat and maneb in mice. Subsequently, blocking Mac1 activation was found to mitigate paraquat and maneb-elicited microglial NLRP3 inflammasome activation in both in vivo and in vitro. Interestingly, stimulating activation of NOX by phorbol myristate acetate abolished the inhibitory effects of Mac1 blocking peptide RGD on paraquat and maneb-provoked NLRP3 inflammasome activation, indicating a key role of NOX in Mac1-mediated NLRP3 inflammasome activation. Furthermore, NOX1 and NOX2, two members of NOX family, and downstream PAK1 and MAPK pathways were recognized to be essential for NOX to regulate NLRP3 inflammasome activation. Finally, a NLRP3 inflammasome inhibitor glybenclamide abrogated microglial M1 activation, neurodegeneration and phosphorylation (Ser129) of α-synuclein elicited by paraquat and maneb, which were accompanied by improved cognitive capacity in mice.

CONCLUSIONS

Mac1 was involved in cognitive dysfunction in a mouse PD model through NOX-NLRP3 inflammasome axis-dependent microglial activation, providing a novel mechanistic basis of cognitive decline in PD.

The Increase of Theta Power and Decrease of Alpha/Theta Ratio as a Manifestation of Cognitive Impairment in Parkinson's Disease

In this study, we aim to assess and examine cognitive functions in Parkinson's Disease patients using EEG recordings, with a central focus on characteristics associated with a cognitive decline. Based on neuropsychological evaluation using Mini-Mental State Examination, Montreal Cognitive Assessment, and Addenbrooke's Cognitive Examination-III, 98 participants were divided into three cognitive groups. All the particpants of the study underwent EEG recordings with spectral analysis. The results revealed an increase in the absolute theta power in patients with Parkinson's disease dementia (PD-D) compared to cognitively normal status (PD-CogN, p=0.00997) and a decrease in global relative beta power in PD-D compared to PD-CogN (p=0.0413). An increase in theta relative power in the left temporal region (p=0.0262), left occipital region (p=0.0109), and right occipital region (p=0.0221) were observed in PD-D compared to PD-N. The global alpha/theta ratio and global power spectral ratio significantly decreased in PD-D compared to PD-N (p = 0.001). In conclusion, the increase in relative theta power and the decrease in relative beta power are characteristic changes in EEG recordings in PD patients with cognitive impairment. Identifying these changes can be a useful biomarker and a complementary tool in the neuropsychological diagnosis of cognitive impairment in Parkinson's Disease.

Early approaches of YKL-40 as a biomarker and therapeutic target for Parkinson's disease

Aim: To investigate whether the estimation of cerebrospinal fluid (CSF) and brain YKL-40 levels may be used as an efficient biomarker for Parkinson's disease (PD). Methods: Lipopolysaccharides (LPS) was injected into the right substantia nigra pars compacta (SNpc). Rats were divided into: control group, early LPS-induced PD group (14 days), and advanced LPS-induced PD group (28 days). YKL-40 and other related factors were detected in CSF and brain tissue. Results: Increased expression of YKL-40 was observed in brain tissue and CSF of PD-induced rats associated with triggered inflammatory cytokine release. Conclusion: The current study was limited to detecting YKL-40 and other inflammatory factors in brain and CSF. YKL-40 may be considered as an early biomarker and therapeutic target for PD.

Current concepts in treating mild cognitive impairment in Parkinson's disease

Impairment in various aspects of cognition is recognized as an important non-motor symptom of Parkinson's disease (PD). Mild cognitive impairment in PD (PD-MCI) is common in non-demented PD patients and is often associated with severity of motor symptoms, disease duration and increasing age. Further, PD-MCI can have a significant negative effect on performance of daily life activities and may be a harbinger of development of PD dementia. Thus, there is significant interest in developing therapeutic strategies to ameliorate cognitive deficits in PD and improve cognitive functioning of PD patients. However, due to significant questions that remain regarding the pathophysiology of cognitive dysfunction in PD, remediation of cognitive dysfunction in PD has proven difficult. In this paper, we will focus on PD-MCI and will review some of the current therapeutic approaches being taken to try to improve cognitive functioning in patients with PD-MCI.

Factors Influencing Habitual Physical Activity in Parkinson’s Disease: Considering the Psychosocial State and Wellbeing of People with Parkinson’s and Their Carers

Participating in habitual physical activity (HPA) may slow onset of dependency and disability for people with Parkinson’s disease (PwP). While cognitive and physical determinants of HPA are well understood, psychosocial influences are not. This pilot study aimed to identify psychosocial factors associated with HPA to guide future intervention development. Sixty-four PwP participated in this study; forty had carer informants. PwP participants wore a tri-axial accelerometer on the lower back continuously for seven days at two timepoints (18 months apart), measuring volume, pattern and variability of HPA. Linear mixed effects analysis identified relationships between demographic, clinical and psychosocial data and HPA from baseline to 18 months. Key results in PwP with carers indicated that carer anxiety and depression were associated with increased HPA volume (p < 0.01), while poorer carer self-care was associated with reduced volume of HPA over 18 months (p < 0.01). Greater carer strain was associated with taking longer walking bouts after 18 months (p < 0.01). Greater carer depression was associated with lower variability of HPA cross-sectionally (p = 0.009). This pilot study provides preliminary novel evidence that psychosocial outcomes from PwP’s carers may impact HPA in Parkinson’s disease. Interventions to improve HPA could target both PwP and carers and consider approaches that also support psychosocial wellbeing.

Resolution of a Parent's Disease: Attachment and Well-Being in Offspring of Parents Diagnosed with Parkinson's Disease

BACKGROUND

Parkinson's disease (PD) is one of the most common chronic, progressive neurodegenerative diseases, with well-developed research focusing on the caregiver-spouse showing low well-being along with predeath grief and feelings of loss among caregivers. However, offspring of a parent diagnosed with PD may also suffer predeath grief and loss even if they are not their parent's main caregiver. Yet, this research is not well developed.

OBJECTIVE

The objective of the current study was to examine offspring's coming to terms with their parent's PD and the well-being of the offspring, within the conceptual framework of attachment theory.

METHODS

Seventy-one Israeli adult children of parents with PD participated in the study and completed self-report questionnaires assessing their resolution of their parent's PD, attachment, well-being, and the severity of the PD symptoms.

RESULTS

Results showed that attachment anxiety negatively associated with higher resolution of the parent's disease, beyond the effect of the PD symptoms' severity. In addition, resolution of the parent's disease was positively associated with the offspring's well-being.

CONCLUSION

Resolution of a parent's PD is highly challenging for offspring with attachment anxiety. Therefore, targeting these individuals within the offspring of parents diagnosed with PD may assist them with coping during this challenging period. This may be especially impactful, as research shows that those offspring who resolve their parent's PD also have higher well-being.

Patient and caregiver outcomes with levodopa-carbidopa intestinal gel in advanced Parkinson’s disease

Levodopa-carbidopa intestinal gel (LCIG) has shown to be efficacious in motor and non-motor symptoms (NMS). Nevertheless, studies with patient Quality of Life (QoL) as a primary endpoint are scarce. To assess the effect of LCIG on Advanced Parkinson’s Disease (APD) patients QoL. Secondarily, the impact on motor symptoms and NMS, emotional well-being, treatment satisfaction, and caregiver QoL, stress, disease burden, anxiety, depression, and work impairment were also investigated. In this prospective, 6-month multicenter postmarketing observational study, LCIG was administered to 59 patients with APD. Endpoints were assessed using validated scales and questionnaires. LCIG significantly improved patient QoL (PDQ-39 mean change ± standard deviation from baseline, −12.8 ± 14.6; P < 0.0001), motor symptoms (UPDRS-III in “On,” −6.5 ± 11.8; P = 0.0002), NMS (NMSS, −35.7 ± 31.1; P < 0.0001), mood (Norris/Bond-Lader VAS, −6.6 ± 21.1; P = 0.0297), fatigue (PFS-16, −0.6 ± 1.0; P = 0.0003), depression (BDI-II, −5.1 ± 9.4; P = 0.0002), anxiety (BAI, −6.2 ± 9.6; P < 0.0001), and patient treatment satisfaction (SATMED-Q, 16.1 ± 16.8; P < 0.0001). There were significant correlations between the change from baseline to 6 months between PDQ-39 and UPDRS-IV, NMSS, BAI, BDI-II, AS, and PFS-16 scores, and Norris/Bond-Lader alertness/sedation factor. Caregiver anxiety also improved (Goldberg anxiety scale, −1.1 ± 1.0; P = 0.0234), but the clinical relevance of this finding is questionable. The serious adverse events reported were similar to those previously described for LCIG. In patients with APD, LCIG improves QoL, motor symptoms and NMS, emotional well-being, and satisfaction with the treatment. Improvement in patient QoL is associated with improvements in motor complications, NMS, anxiety, depression, apathy and fatigue. Improvements in patients’ QoL does not correspond with improvements in caregivers’ QoL or burden.

Brain Atrophy Mediates the Relationship between Misfolded Proteins Deposition and Cognitive Impairment in Parkinson's Disease

Parkinson’s disease is associated with cognitive decline, misfolded protein deposition and brain atrophy. We herein hypothesized that structural abnormalities may be mediators between plasma misfolded proteins and cognitive functions. Neuropsychological assessments including five domains (attention, executive, speech and language, memory and visuospatial functions), ultra-sensitive immunomagnetic reduction-based immunoassay (IMR) measured misfolded protein levels (phosphorylated-Tau, Amyloidβ-42 and 40, α-synuclein and neurofilament light chain) and auto-segmented brain volumetry using FreeSurfur were performed for 54 Parkinson’s disease (PD) patients and 37 normal participants. Our results revealed that PD patients have higher plasma misfolded protein levels. Phosphorylated-Tau (p-Tau) and Amyloidβ-42 (Aβ-42) were correlated with atrophy of bilateral cerebellum, right caudate nucleus, and right accumbens area (RAA). In mediation analysis, RAA atrophy completely mediated the relationship between p-Tau and digit symbol coding (DSC). RAA and bilateral cerebellar cortex atrophy partially mediated the Aβ-42 and executive function (DSC and abstract thinking) relationship. Our study concluded that, in PD, p-Tau deposition adversely impacts DSC by causing RAA atrophy. Aβ-42 deposition adversely impacts executive functions by causing RAA and bilateral cerebellum atrophy.

Validation of the Parkinson's Disease Caregiver Burden Questionnaire in Progressive Supranuclear Palsy

Progressive supranuclear palsy (PSP) is an atypical Parkinson syndrome with axial akinetic-rigid symptoms, early postural instability, and ocular motor impairments. Patients experience a rapid loss of autonomy and care dependency; thus, caregivers must assist in the activities of daily living early in the course of the disease. Caregiver burden is an extremely important factor in disease management. However, there are no specific questionnaires for assessment of caregiver burden in PSP. This study aims to validate the Parkinson's disease caregiver burden questionnaire (PDCB) as a specific measure of caregiver burden in PSP. PSP patients were assessed by the PSP rating scale, PSP quality-of-life questionnaire (PSP-QoL), Montreal cognitive assessment test (MoCA), and geriatric depression scale (GDS-15). Caregivers filled out the short form 36-health survey, GDS-15, PDCB, and the caregiver burden inventory (CBI). 22 patient caregiver pairs completed the study. PDCB showed a highly significant correlation with the CBI (r 0.911; p < 0.001). Internal reliability of the PDCB measured by Cronbach's alpha was favourable at 0.803. These data support the specificity of the PDCB in PSP caregivers. Future studies with larger sample sizes of PSP patients and caregivers and a multicentric longitudinal design should be performed to gain further insight of caregiver burden in PSP.

Senescence and Inflammatory Markers for Predicting Clinical Progression in Parkinson's Disease: The ICICLE-PD Study

Background:

Cognitive decline is a frequent complication of Parkinson’s disease (PD) and the identification of predictive biomarkers for it would help in its management.

Objective:

Our aim was to analyse whether senescence markers (telomere length, p16 and p21) or their change over time could help to better predict cognitive and motor progression of newly diagnosed PD patients. We also compared these senescence markers to previously analysed markers of inflammation for the same purpose.

Methods:

This study examined the association of blood-derived markers of cell senescence and inflammation with motor and cognitive function over time in an incident PD cohort (the ICICLE-PD study). Participants (154 newly diagnosed PD patients and 99 controls) underwent physical and cognitive assessments over 36 months of follow up. Mean leukocyte telomere length and the expression of senescence markers p21 and p16 were measured at two time points (baseline and 18 months). Additionally, we selected five inflammatory markers from existing baseline data.

Results:

We found that PD patients had shorter telomeres at baseline and 18 months compared to age-matched healthy controls which also correlated to dementia at 36 months. Baseline p16 levels were associated with faster rates of motor and cognitive decline over 36 months in PD cases, while a simple inflammatory summary score at baseline best predicted cognitive score over this same time period in PD patients.

Conclusion:

Our study suggests that both inflammatory and senescence markers (p16) are valuable predictors of clinical progression in PD patients.

Experience and Impact of OFF Periods in Parkinson's Disease: A Survey of Physicians, Patients, and Carepartners

BACKGROUND

OFF periods impair quality of life in Parkinson's disease but the nature and degree of this impact is largely unquantified. Optimal treatment relies on assessing the experience and impact of these periods on patients and their carepartners.

OBJECTIVES

To understand the experience and impact of OFF periods on their lives.

METHODS

Informed by qualitative interviews we designed questionnaires and surveyed neurologists, people with Parkinson's disease and carepartners.

RESULTS

50 general neurologists, 50 movement disorder neurologists, 442 patients (median disease duration 5 years) and 97 carepartners were included. The most common OFF symptoms reported by patients and carepartners were stiffness, slowness of movement and changes in gait. Non-motor symptoms were less common. A higher proportion of carepartners reported each symptom. A minority of neurologists recognized pain, sweating and anxiety as possible symptoms of OFF periods. The three OFF symptoms most frequently designated as having great impact by people with Parkinson's disease were changes in gait, slowness and stiffness. In contrast, cognitive impairment was most frequently rated as having great impact on carepartners. OFF periods were reported to impact many aspects of the lives of both patients and carepartners.

CONCLUSIONS

In people with Parkinson's disease of under 10 years duration, motor symptoms of OFF periods predominate in impact, however cognitive impairment has great impact on carepartners. Education is needed for neurologists regarding the non-motor aspects of OFF. The importance of involving carepartners in the assessment regarding OFF periods is supported by the higher frequency of symptom reporting by carepartners, and the significant impact on their lives.

Microglial activation contributes to cognitive impairments in rotenone-induced mouse Parkinson's disease model

Background

Cognitive decline occurs frequently in Parkinson’s disease (PD), which greatly decreases the quality of life of patients. However, the mechanisms remain to be investigated. Neuroinflammation mediated by overactivated microglia is a common pathological feature in multiple neurological disorders, including PD. This study is designed to explore the role of microglia in cognitive deficits by using a rotenone-induced mouse PD model.

Methods

To evaluate the role of microglia in rotenone-induced cognitive deficits, PLX3397, an inhibitor of colony-stimulating factor 1 receptor, and minocycline, a widely used antibiotic, were used to deplete or inactivate microglia, respectively. Cognitive performance of mice among groups was detected by Morris water maze, objective recognition, and passive avoidance tests. Neurodegeneration, synaptic loss, α-synuclein phosphorylation, glial activation, and apoptosis were determined by immunohistochemistry and Western blot or immunofluorescence staining. The gene expression of inflammatory factors and lipid peroxidation were further explored by using RT-PCR and ELISA kits, respectively.

Results

Rotenone dose-dependently induced cognitive deficits in mice by showing decreased performance of rotenone-treated mice in the novel objective recognition, passive avoidance, and Morris water maze compared with that of vehicle controls. Rotenone-induced cognitive decline was associated with neurodegeneration, synaptic loss, and Ser129-phosphorylation of α-synuclein and microglial activation in the hippocampal and cortical regions of mice. A time course experiment revealed that rotenone-induced microglial activation preceded neurodegeneration. Interestingly, microglial depletion by PLX3397 or inactivation by minocycline significantly reduced neuronal damage and α-synuclein pathology as well as improved cognitive performance in rotenone-injected mice. Mechanistically, PLX3397 and minocycline attenuated rotenone-induced astroglial activation and production of cytotoxic factors in mice. Reduced lipid peroxidation was also observed in mice treated with combined PLX3397 or minocycline and rotenonee compared with rotenone alone group. Finally, microglial depletion or inactivation was found to mitigate rotenone-induced neuronal apoptosis.

Conclusions

Taken together, our findings suggested that microglial activation contributes to cognitive impairments in a rotenone-induced mouse PD model via neuroinflammation, oxidative stress, and apoptosis, providing novel insight into the immunopathogensis of cognitive deficits in PD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-020-02065-z.

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

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_p²=0.092) and a statistical trend for overall executive functions (p=0.095, η_p²=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_p²=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.

Cognitive decline in Parkinson's disease is associated with reduced complexity of EEG at baseline

Parkinson’s disease is a neurodegenerative disorder requiring motor signs for diagnosis, but showing more widespread pathological alterations from its beginning. Compared to age-matched healthy individuals, patients with Parkinson’s disease bear a 6-fold lifetime risk of dementia. For individualized counselling and treatment, prognostic biomarkers for assessing future cognitive deterioration in early stages of Parkinson’s disease are needed. In a case–control study, 42 cognitively normal patients with Parkinson’s disease were compared with 24 healthy control participants matched for age, sex and education. Tsallis entropy and band power of the δ, θ, α, β and γ-band were evaluated in baseline EEG at eyes-open and eyes-closed condition. As the θ-band showed the most pronounced differences between Parkinson’s disease and healthy control groups, further analysis focussed on this band. Tsallis entropy was then compared across groups with 16 psychological test scores at baseline and follow-ups at 6 months and 3 years. In group comparison, patients with Parkinson’s disease showed lower Tsallis entropy than healthy control participants. Cognitive deterioration at 3 years was correlated with Tsallis entropy in the eyes-open condition (P < 0.00079), whereas correlation at 6 months was not yet significant. Tsallis entropy measured in the eyes-closed condition did not correlate with cognitive outcome. In conclusion, the lower the EEG entropy levels at baseline in the eyes-open condition, the higher the probability of cognitive decline over 3 years. This makes Tsallis entropy a candidate prognostic biomarker for dementia in Parkinson’s disease. The ability of the cortex to execute complex functions underlies cognitive health, whereas cognitive decline might clinically appear when compensatory capacity is exhausted.

Evaluation of START (STrAtegies for RelaTives) adapted for carers of people with Lewy body dementia

Family carers of people with Lewy body dementia (LBD) have a particularly high burden of care, as LBD has a faster rate of decline, greater physical dependence and additional neuropsychiatric disturbances compared with other dementias. Despite this, there are no evidence-based support services designed specifically for LBD carers. STrAtegies for RelaTives (START) is an eight-session, individually delivered coping therapy that has been shown in a randomised controlled trial to reduce depression and anxiety symptoms and increase quality of life in carers of people with dementia, with effects lasting several years. We adapted START for LBD, and piloted its use both face-to-face and on the phone with 10 carers to test acceptability and indications of similar effects in this group. Our findings suggest that the therapy was acceptable and feasible using either delivery mode, providing much appreciated and needed strategies, education and support for carers of people with LBD. Trials of effectiveness are now needed.

Belastungen in der Betreuung von Parkinson-Patientinnen und - Patienten

Patientinnen und Patienten (Pat.) mit Parkinson-Krankheit bedürfen mit zunehmender Krankheitsdauer und Schweregrad persönlicher Betreuung, die meist von weiblichen Angehörigen gewährleistet wird. Die Belastungen für pflegende Angehörige resultieren einerseits aus den motorischen Beeinträchtigungen der Pat., andererseits von neurokognitiven und neuropsychiatrischen Symptomen sowie Verhaltensstörungen, Störungen des autonomen Nervensystems, der Miktion, des Schlafes und der Selbstständigkeit. Gesundheitliche Probleme der Betreuungsperson, u. a. Depression und Angst, emotionale Probleme mit dem Pflegling, Beeinträchtigung des Schlafs, sowie Einschränkungen in persönlichen Anliegen, Beruf, Familie, Freizeitgestaltung, sozialen Aktivitäten, finanzielle Einbußen und mangelhafte soziale Unterstützung stellen weitere Belastungsfaktoren dar. Personen mit dem Risiko einer erheblichen Betreuungsbelastung sind frühzeitig zu identifizieren, um ihnen Informationen über die Krankheit und Unterstützungsmöglichkeiten sowie entsprechende personelle, psychologische und finanzielle Unterstützung zukommen zu lassen.

Psychosocial Adjustment of In-Home Caregivers of Family Members with Dementia and Parkinson's Disease: A Comparative Study

Neurodegenerative diseases such as Parkinson's and dementia are highly prevalent worldwide. People who suffer from these disorders often receive in-home care and assistance from family members, who must dedicate a considerable amount of time to the care recipient. The study of family caregivers' psychosocial adjustment to the degenerative processes of both conditions is of interest due to the implications for the quality of life of both the care receiver and the caregiver, as well as other family members. This study compares the psychosocial adjustment of family members who care for people with dementia and Parkinson's disease and identifies the main sociodemographic variables that affect the processes of adjustment to both conditions. To this end, the Psychosocial Adjustment to Illness Scale (PAIS-SR) and a sociodemographic form were administered to 157 family caregivers in Navarre, Spain. The results show that adjustment to the disease in family caregivers of people with Parkinson's disease and dementia is, in general, satisfactory and related to variables such as place of residence, income, and employment status. The illness itself (Parkinson's or dementia), however, is found to be the most influential variable in the level of psychosocial adjustment.

Association of Motor and Cognitive Symptoms with Health-Related Quality of Life and Caregiver Burden in a German Cohort of Advanced Parkinson's Disease Patients

Parkinson's disease (PD) is a chronic progressive movement disorder with severe reduction in patients' health-related quality of life (HR-QoL). Motor and cognitive symptoms are especially linked with decreased PD patients' HR-QoL. However, the relationship of these symptoms to caregiver burden is relatively unclear. Influence of the Montreal Cognitive Assessment scale (MoCA) as a cognitive screening tool and Movement Disorders Society Unified Parkinson's disease Rating Scale MDS-UPDRS symptoms in relation to patients' HR-QoL and caregivers` burden was analyzed. PD patients (n = 124) completed MDS-UPDRS, MoCA, and the PD questionnaire 8 (PDQ-8) as a measure of quality of life. Caregivers (n = 78) were assessed by the PD caregiver burden inventory (PDCB). PDQ-8 and PDCB scores were regressed on MDS-UPDRS subscales and MoCA subscores. PDQ-8 correlated with attention (R² 0.1282; p < 0.001) and executive (R² 0.0882; p 0.001) MoCA subscores and all parts of the MDS-UPDRS. PDCB correlated most strongly with MDS-UPDRS part III motor symptoms (R² 0.2070; p < 0.001) and the MoCA attention subscore (R² 0.1815; p < 0.001). While all facets of PD symptoms assessed by the MDS-UPDRS relate to PD patients' quality of life, motor symptoms are the most relevant factor for the prediction of caregiver burden. In addition, patients' attentional symptoms seem to affect not only them, but also their caregivers. These findings show the potential of a detailed analysis of MDS-UPDRS and MoCA performance in PD patients.

Mindfulness and Psychological Flexibility are Inversely Associated with Caregiver Burden in Parkinson's Disease

Parkinson's disease (PD) is a neurodegenerative movement disorder with progressive impairments in activities of daily living. With disease progression, people with PD (PwP) need more help and care from their spouses or professional caregivers. Identifying factors that help caregivers to cope with their burden is needed to frame future interventions for PwP caregivers. Mindfulness and psychological flexibility might be factors contributing to resilience against the burden of giving care. In this cross-sectional questionnaire-based study, 118 PwP and their respective primary caregivers were included. Caregivers reported moderate burden and only mild depressive symptoms. Mindfulness measured by the Mindfulness Attention and Awareness scale (p 0.003) and psychological flexibility measured by Acceptance and Actions Questionnaire II (p0.001) correlated negatively with caregiver burden. Data from this study indicate mindfulness and psychological flexibility are factors contributing to resilience against caregiver burden. Future interventions to reduce burden in PwP caregivers might be improved by the inclusion of mindfulness training programs.

Effects of Home-Based Working Memory Training on Visuo-Spatial Working Memory in Parkinson's Disease: A Randomized Controlled Trial

BACKGROUND

Cognitive impairment is a very frequent and severe nonmotor symptom of Parkinson's disease (PD). Early intervention in this at-risk group for cognitive decline may be crucial for long-term preservation of cognitive functions. Computerized working memory training (WMT) has been proven beneficial in non-PD patient populations, but such evidence is still needed for patients with PD.

OBJECTIVE

This study aimed to evaluate the effect of WMT on visuo-spatial working memory (WM) in cognitively unimpaired patients with PD.

METHODS

A single-blind randomized controlled trial encompassing 76 patients with PD but no cognitive impairment according to level II diagnostic criteria was conducted. Thirty-seven patients engaged in home-based adaptive WMT 5 times per week for a period of 5 weeks, whereas the remaining patients were in the waiting list arm of the study (control group [CG]). Working memory performance was evaluated using a computerized task before and after intervention and at 14-week follow-up, allowing to quantify the precision of WM on a continuous scale, ie, to test not only if an item was remembered but also how well the location of this item was retained.

RESULTS

Coincidently, the WMT group showed slightly worse WM performance compared with the CG at baseline, which was ameliorated after WMT. This training-induced effect remained stable until follow-up.

CONCLUSION

Patients showing relatively low WM performance, despite not formally diagnosable as Parkinson's disease with mild cognitive impairment (PD-MCI), seem to benefit from home-based WMT. Thus, WMT could potentially be implemented in future trials as a time- and cost-efficient route to counteract subtle cognitive changes in early disease stages.

TRIAL REGISTRATION

German Clinical Trial Register (drks.de, DRKS00009379).

Care Burden and Mental Ill Health in Spouses of People With Parkinson Disease Dementia and Lewy Body Dementia

OBJECTIVES

To explore and compare levels of mental health, care burden, and relationship satisfaction among caregiving spouses of people with mild cognitive impairment or dementia in Parkinson disease (PD-MCI or PDD) or dementia with Lewy bodies (DLB).

METHODS

Spouses (n = 136) completed measures of mood, stress, resilience, general health, quality of life, care burden, and relationship satisfaction, as well as sociodemographic factors. Additionally, data on motor and neuropsychiatric symptom severity of people with PD-MCI, PDD, or DLB were obtained in a subsample.

RESULTS

Most spouses were married women (>85%) who provided a median of 4 years of care and 84 hours of weekly care. Among these, relationship dissatisfaction, stress, anxiety, care burden, and feelings of resentment were common. Spouses of people with PDD and DLB had significantly higher rates of burden, resentment, and depression compared to spouses of people with PD-MCI. Furthermore, unique group differences emerged whereby spouses of people with PDD had significantly longer duration of care provision, higher stress, more relationship dissatisfaction, and fewer positive interactions, compared to PD-MCI group, whereas anxiety and lower levels of mental health were prominent in spouses of people with DLB, compared to PD-MCI group. Despite this, the majority of spouses reported good quality of life, resilience, and satisfaction with the caring role.

CONCLUSION

Both PDD and DLB significantly contribute to poorer mental health and higher levels of care burden in spouses. Clinicians should actively screen the risk of burden, stress, depression, and anxiety among caregiving spouses of people with these conditions.

Low Pulvinar Intensity in Susceptibility-Weighted Imaging May Suggest Cognitive Worsening After Deep Brain Stimulation Therapy in Patients With Parkinson's Disease

Purpose: Deep brain stimulation (DBS) is an established therapy for Parkinson's disease (PD). However, deteriorating cognitive function after DBS is a considerable problem for affected patients. This study was undertaken to assess whether pulvinar findings in susceptibility-weighted imaging (SWI) can suggest cognitive worsening.

Methods: We examined 21 patients with PD who underwent DBS along with SWI and neuromelanin-sensitive MR imaging (NMI). We further assessed pulvinar hypointensity based on the SWI findings and also the area of the substantia nigra (SN) pars compacta in NMI. We then examined associations among cognitive changes, pulvinar hypointensity, and SN area. The cognitive function of the patient immediately before surgery was compared with function at 1 year postoperatively.

Results: Pulvinar hypointensity in SWI was found in 11 of 21 patients with PD at baseline. One year postoperatively, six of the 21 patients demonstrated a Mini-Mental State Examination score that was ≥3 points lower than the baseline score. We observed pulvinar hypointensity in SWI before DBS surgery in five of these six patients (p = 0.072). During the first postoperative year, six of 21 patients reported both transient or permanent hallucinations; we observed pulvinar hypointensity in these six patients, while 10 patients without pulvinar hypointensity had no hallucinations.

Conclusion: Pulvinar hypointensity in SWI in patients with PD may provide information that is useful for suggesting cognitive deterioration after DBS treatment.

Multidimensional Care Burden in Parkinson-Related Dementia

BACKGROUND AND OBJECTIVE

Providing care to people with Parkinson-related dementia (PwPRD) may result in significant stress, strain, and burden for life partners. A common measurement of life partner burden is the Zarit Burden Interview (ZBI), which considers "burden" as a unitary concept; however, burden is highly complex and most likely comprises several dimensions. This study aimed to explore the factor structure of the ZBI in life partners of PwPRD and to examine the relationships among the emerging factors and the demographic and clinical features.

METHODS

Life partners of PwPRD participated in home-based quantitative assessments and self-completed postal questionnaires. The assessment battery included ZBI, measures of relationship satisfaction, mood, stress, resilience, health, quality of life, feelings related to care provision, and sociodemographic questions. Data on PwPRDs' motor and neuropsychiatric symptom severity were also elicited in home-based assessments.

RESULTS

An exploratory factor analysis (principal axis factoring) of ZBI, conducted with 127 life partners, revealed five burden dimensions: social and psychological constraints, personal strain, interference with personal life, concerns about future, and guilt. These burden factors were associated with lower relationship satisfaction, mental health, and resilience, and higher stress, anxiety, depression, resentment, negative strain, and PwPRD motor severity. In multiple linear regression analyses, where each factor score was the dependent variable, stress, negative strain, and resentment emerged as significant predictors of specific burden dimensions.

CONCLUSIONS

Burden is a complex and multidimensional construct. Interventions should address specific types of burden among life partners of PwPRD to support couples' relationships and maintain quality of life.

Caregiver burden and family functioning in different neurological diseases

Aim of this study is to examine caregiver burden and family functioning in different neurological conditions. Forty-two primary caregivers of patients with Amyotrophic Lateral Sclerosis (ALS), Alzheimer's Disease and other dementia (AD), Parkinson's Disease (PD), Acquired Brain Injuries (ABI) and Multiple Sclerosis (MS) were administered scales for the evaluation of caregiver burden (CBI) and family functioning (FACES IV). Caregiver burden was overall high, with caregivers of patients with ALS and ABI having exceeded the CBI cut-off score for possible burn-out. The average scores of caregivers of patients with AD or other dementia and PD were close to the cut-off score, whereas those of caregivers of patients with MS were significantly lower than the others. Family cohesion, family satisfaction and the quality of family communication were associated with reduced levels of caregiver burden, whereas disengagement was associated with a higher burden. The data from the present study confirm that caregiver burden is a relevant issue in the context of neurological diseases, especially for those causing higher degrees of impairment. Significant correlations with family functioning emerged as well, highlighting the importance of studying and treating caregiver burden within the context of family relations.

Goal-orientated cognitive rehabilitation for dementias associated with Parkinson's disease-A pilot randomised controlled trial

OBJECTIVE

To examine the appropriateness and feasibility of cognitive rehabilitation for people with dementias associated with Parkinson's in a pilot randomised controlled study.

METHODS

This was a single-blind pilot randomised controlled trial of goal-oriented cognitive rehabilitation for dementias associated with Parkinson's. After goal setting, participants were randomised to cognitive rehabilitation (n = 10), relaxation therapy (n = 10), or treatment-as-usual (n = 9). Primary outcomes were ratings of goal attainment and satisfaction with goal attainment. Secondary outcomes included quality of life, mood, cognition, health status, everyday functioning, and carers' ratings of goal attainment and their own quality of life and stress levels. Assessments were at 2 and 6 months following randomisation.

RESULTS

At 2 months, cognitive rehabilitation was superior to treatment-as-usual and relaxation therapy for the primary outcomes of self-rated goal attainment (d = 1.63 and d = 1.82, respectively) and self-rated satisfaction with goal attainment (d = 2.04 and d = 1.84). At 6 months, cognitive rehabilitation remained superior to treatment-as-usual (d = 1.36) and relaxation therapy (d = 1.77) for self-rated goal attainment. Cognitive rehabilitation was superior to treatment as usual and/or relaxation therapy in a number of secondary outcomes at 2 months (mood, self-efficacy, social domain of quality of life, carers' ratings of participants' goal attainment) and at 6 months (delayed recall, health status, quality of life, carer ratings of participants' goal attainment). Carers receiving cognitive rehabilitation reported better quality of life, health status, and lower stress than those allocated to treatment-as-usual.

CONCLUSIONS

Cognitive rehabilitation is feasible and potentially effective for dementias associated with Parkinson's disease.

Coping with Cognitive Impairment in People with Parkinson's Disease and Their Carers: A Qualitative Study

Cognitive impairment is common in Parkinson's disease (PD). However, the psychosocial impact of living and coping with PD and cognitive impairment in people with PD and their carers have not been explored. This paper draws on a qualitative study that explores the subjective impact of cognitive impairment on people with PD and their carers. Thirty-six one-to-one interviews were completed; people with PD were from three groups: normal cognition, mild cognitive impairment, and dementia. Data collection and analysis were iterative, and verbatim transcripts were analysed using thematic analysis. Themes were interpreted in consultation with coping and adaptation theory. The analysis revealed four main themes: threats to identity and role, predeath grief and feelings of loss in carers, success and challenges to coping in people with PD, and problem-focused coping and finding meaning in caring. Our data highlight how cognitive impairment can threaten an individual's self-perception; the ostensible effects of cognitive impairment depended on the impact individual's perceived cognitive impairment had on their daily lives. For carers, cognitive impairment had a greater emotional impact than the physical symptoms of PD. The discussion that developed around protective factors provides possible opportunities for future interventions, such as psychological therapies to improve successful adjustment.

Cognitive impairment in Parkinson's disease: impact on quality of life of carers

BACKGROUND

The quality of life (QoL) of informal caregivers of people with Parkinson's disease (PD) (PwP) can be affected by the caring role. Because of cognitive symptoms and diminished activities of daily living, in addition to the management of motor symptoms, carers of PwP and cognitive impairment may experience increased levels of burden and poorer QoL compared with carers of PwP without cognitive impairment. This study aimed to investigate the impact of cognitive impairment in PD upon QoL of carers.

METHODS

Approximately 36 months after diagnosis, 66 dyadic couples of PwP and carers completed assessments. PwP completed a schedule of neuropsychological assessments and QoL measures; carers of PwP completed demographic questionnaires and assessments of QoL. Factor scores of attention, memory/executive function and global cognition, as derived by principal component analysis, were used to evaluate cognitive domains.

RESULTS

Hierarchical regression analysis found lower Montreal Cognitive Assessment was a significant independent predictor of poorer carer QoL, in addition to number of hours spent caregiving, carer depression and PD motor severity. Attentional deficits accounted for the largest proportion of variance of carer QoL. Carers of PwP and dementia (n = 9) had significantly poorer QoL scores compared with PwP and mild cognitive impairment (n = 18) or normal cognition (n = 39) carers (p < 0.01).

CONCLUSIONS

Attentional deficits were the strongest predictor of carer QoL compared with other cognitive predictors. Carers for those with PD dementia reported the poorest QoL. Interventions such as respite or cognitive behavioural therapy to improve mood and self-efficacy in carers may improve carer QoL. © 2016 The Authors. International Journal of Geriatric Psychiatry published by John Wiley & Sons, Ltd.