Telehealth Cognitive Behavior Therapy to Reduce Anxiety in People Living with Cognitive Impairment: A Randomized Feasibility Pilot Study.

OBJECTIVES: To evaluate the feasibility of telehealth-based cognitive behavior therapy for people living with cognitive impairment experiencing anxiety (Tele-CBT), and to assess whether this leads to improvements in anxiety, depression, and quality of life post-intervention. METHODS: This was a single-blind randomized feasibility pilot trial of the Tele-CBT versus usual care. People living with mild cognitive impairment or dementia experiencing anxiety were recruited and randomized to receive Tele-CBT (n = 5) or continue usual care (n = 5). Feasibility data comprised recruitment uptake and retention, adherence, and ease of use. Outcomes of anxiety (primary outcome - Rating Anxiety in Dementia; RAID), depression, stress, and quality of life were measured pre- and post-intervention. RESULTS: Intervention feasibility was demonstrated through minimal attrition, acceptability, and ease of use via videoconferencing. Both groups showed a decrease of anxiety symptoms (RAID) from baseline to post-assessment. CONCLUSIONS: The Tele-CBT program was acceptable to use via videoconferencing. Reduced anxiety symptoms were observed in both groups at post-. An RCT with a larger sample is required to determine the efficacy and implementation of the intervention. CLINICAL IMPLICATIONS: This study indicates the feasibility of videoconference CBT to address anxiety experienced by people living with cognitive impairment with minimal assistance from support persons.

Hippocampal resting-state connectivity is associated with posterior-cortical cognitive impairment in Parkinson's disease.

AIM: Frontal and posterior-cortical cognitive subtypes in Parkinson's disease (PD) present with executive/attention and memory/visuospatial deficits, respectively. As the posterior-cortical subtype is predicted to progress rapidly toward dementia, the present study aimed to explore biological markers of this group using resting-state functional magnetic resonance imaging (rs-fMRI). METHODS: K-means cluster analysis delineated subtypes (cognitively intact, frontal, posterior-cortical, and globally impaired) among 85 people with PD. A subset of PD participants (N = 42) and 20 healthy controls (HCs) underwent rs-fMRI. Connectivity of bilateral hippocampi with regions of interest was compared between posterior-cortical, cognitively intact, and HC participants using seed-based analysis, controlling for age. Exploratory correlations were performed between areas of interest from the group analysis and a series of cognitive tests. RESULTS: The posterior-cortical subtype (N = 19) showed weaker connectivity between the left hippocampus and right anterior temporal fusiform cortex compared to the cognitively intact (N = 11) group, p-false discovery rate (FDR) = .01, and weaker connectivity between bilateral hippocampi and most fusiform regions compared to HCs (N = 20). No differences were found between HCs and cognitively intact PD. Exploratory analyses revealed strongest associations between connectivity of the right anterior temporal fusiform cortex and left hippocampus with category fluency (p-FDR = .01). CONCLUSION: Results suggest that weakened connectivity between the hippocampus and fusiform region is a unique characteristic of posterior-cortical cognitive deficits in PD. Further exploration of hippocampal and fusiform functional integrity as a marker of cognitive decline in PD is warranted.

Prototype development of the Mental Health benchmarking Industry Tool for residential aged Care (MHICare Tool): a protocol paper of a two-stage sequential and mixed methods codesign study.

OBJECTIVES: Current mental health practices for people living in residential aged care (RAC) facilities are poor. In Australia, there are no mechanisms to monitor and promote mental health for people living in RAC, including those who experience changed behaviours and psychological symptoms. The aim of this study is to improve current practices and mental health outcomes for people living in RAC facilities by codesigning a Mental Health benchmarking Industry Tool for residential aged Care (MHICare Tool). METHODS: A two-stage sequential and mixed methods codesign methodology will be used. Stage 1 will include qualitative interviews and focus groups to engage with residents, family/care partners and RAC staff to ascertain mental healthcare practices and outcomes of greatest significance to them. Adapted concept mapping methods will be used to rank identified issues of concern in order of importance and changeability, and to generate draft quality indicators. Stage 2 will comprise a Delphi procedure to gain the wider consensus of expert panel views (aged care industry, academic, clinical) on the performance indicators to be included, resulting in the codesigned MHICare Tool. ETHICS AND DISSEMINATION: This study has been reviewed and approved by the University of Queensland Human Research Ethics Committee (HREC/2019002096). This project will be carried out according to the National Statement on Ethical Conduct in Human Research (2007). The study's findings will be published in peer-reviewed journals and disseminated at national and international conferences and through social media. CONCLUSION: This protocol reports structured methods to codesign and develop a mental health performance indicator tool for use in Australian RAC.

Predictors of the placebo response in a nutraceutical randomized controlled trial for depression.

OBJECTIVE: The placebo response in depression studies is the change in symptoms amongst those who receive an inactive treatment. Many well-designed randomized controlled trials (RCTs) of depression have a high proportion of placebo responders, with little understanding as to why. The present study assesses characteristics associated with the placebo response in a nutraceutical trial with a large proportion of placebo responders. METHODS: This is a secondary analysis of a nutraceutical depression RCT which identified no overall treatment benefit relative to placebo (n = 69 in placebo group). We investigated participant characteristics such as socio-demographics, clinical features, and recruitment methods, and their association with the placebo response. Monoaminergic genetic polymorphisms were also assessed. Placebo response was measured based on change in Montgomery-Asberg Depression Rating Scale score. The association of these hypothesis-driven variables of interest and the placebo response was examined using linear mixed effects models. RESULTS: Greater levels of education, particularly pursuing post-high school education, better self-reported general health, marriage/de facto, greater improvement in the first trial week, and more failed antidepressant therapies in the current depressive episode were associated with greater placebo response. An increased placebo response was not found in those recruited via social media nor in those with concomitant antidepressant therapy. Single nucleotide polymorphisms from the tryptophan hydroxylase 1 (TPH1) gene (A779C and A218C) were weakly associated with greater placebo response, although the evidence was attenuated after accounting for multiple comparisons. CONCLUSION: This is, to our knowledge, the first study within nutraceutical research for depression to assess the association between participant characteristics and variation in the placebo response. Several variables appeared to predict the placebo response. Such findings may encourage future trial designs which could dampen placebo response, improve assay sensitivity, and allow for treatment effects to be potentially more detectable. Please cite this article as: Arnold R, Murphy-Smith J, Ng CH, Mischoulon D, Byrne GJ, Bousman CA, Stough C, Berk M, Sarris J. Predictors of the placebo response in a nutraceutical randomized controlled trial for depression. J Integr Med. 2024; 22(1): 46-53.

Feasibility and Acceptability of a Videoconferencing CBT Intervention for Anxiety in People with Parkinson's Disease.

OBJECTIVES: In people with Parkinson's disease (PwPD), non-motor symptoms such as anxiety are common and have negative impacts on their quality of life. There are currently few interventions that address anxiety in PwPD, and access to diagnosis and treatment is often limited for those living in rural areas. The aim of this study was to evaluate the feasibility and acceptability of a telehealth videoconferencing CBT intervention for anxiety in PwPD. METHODS: A pre- and post-test feasibility study (N = 10) was conducted and evaluated utilizing the RE-AIM framework (Reach, Effectiveness, Adoption, Implementation, and Maintenance). RESULTS: Lack of access to the internet and videoconferencing technology were identified as barriers to participation. Physical health issues also impacted recruitment and retention. Non-completers were significantly older and less likely to have a carer involved in the intervention. Clinician adoption of the intervention was low while participant acceptability of videoconferencing technology varied and required carer support. CONCLUSIONS: Providing access to technology and support to overcome technological issues, as well as telehealth training for clinicians, are recommended in future studies to improve recruitment, retention, and implementation. CLINICAL IMPLICATIONS: Identification of barriers and facilitators provides future studies with the knowledge to tailorize their program to better suit PwPD.

Anxiety Symptoms in Australian Memory Clinic Attendees with Cognitive Impairment: Differences Between Self-, Carer-, and Clinician-Report Measures.

OBJECTIVES: To identify the prevalence of anxiety symptoms using a variety of instruments in an Australian memory clinic sample. METHODS: This is an exploratory cross-sectional study using a purposive consecutive series sample of 163 individuals and their carers who attended a Brisbane, Australia, memory clinic in 2012-2015. Descriptive statistics and correlation analyses were performed to explore different approaches to measuring anxiety in the sample, using clinician-rated, self-report and carer-report measures. RESULTS: The mean age of participants was 78 years, nearly 53% were females. Over 70% of participants with mild cognitive impairment (MCI) and dementia (n = 163) experienced mild to moderate anxiety per a clinician-rated measure (HAM-A), which moderately correlated with carer-report anxiety (IQAD; rs =.59, p < .001). Only weak correlations of these measures with self-report anxiety (GAI) were detected. CONCLUSIONS: Mild to moderate anxiety symptoms were frequent in memory clinic attendees diagnosed with MCI or dementia using the HAM-A, suggesting experiences of subclinical anxiety symptoms. CLINICAL IMPLICATIONS: Self- as well as carer-report screening tools should be used in memory clinics in addition to routinely administered neuropsychiatric assessments to support early identification of anxiety symptoms and mapping of available post-diagnostic care pathways for people diagnosed with cognitive impairment.

Levetiracetam for the treatment of mild cognitive impairment in Parkinson's disease: a double-blind controlled proof-of-concept trial protocol.

BACKGROUND: Mild memory impairment, termed amnestic mild cognitive impairment (aMCI), is associated with rapid progression towards dementia in Parkinson's disease (PD). Studies have shown hyperactivation of hippocampal DG/CA3 subfields during an episodic memory task as a biomarker of aMCI related to Alzheimer's disease. This project investigates the feasibility of a trial to establish the efficacy of a repurposed antiepileptic drug, levetiracetam, in low doses as a putative treatment to target DG/CA3 hyperactivation and improve episodic memory deficits in aMCI in PD. Based on previous work, it is hypothesized that levetiracetam will normalize DG/CA3 overactivation in PD-aMCI participants and improve memory performance. METHODS: Twenty-eight PD-aMCI participants, 28 PD participants without memory impairment (PD-nMI), and 28 healthy controls will be recruited. PD-aMCI participants will undertake a 12-week randomized, placebo-controlled, double-blind cross-over trial with a 14-day treatment of 125 mg levetiracetam or placebo twice daily, separated by a 4-week washout period. After each treatment period, participants will complete an episodic memory task designed to tax hippocampal subregion-specific function during high-resolution functional magnetic resonance imaging (fMRI). PD-nMI and healthy controls will undergo the fMRI protocol only, to compare baseline DG/CA3 subfield activity. RESULTS: Episodic memory task performance and functional activation in the DG/CA3 subfield during the fMRI task will be primary outcome measures. Global cognition, PD severity, and adverse events will be measured as secondary outcomes. Recruitment, eligibility, and study completion rates will be explored as feasibility outcomes. CONCLUSIONS: This study, the first of its kind, will establish hippocampal subregion functional impairment and proof of concept of levetiracetam as an early therapeutic option to reduce dementia risk in PD. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04643327 . Registered on 25 November 2020.

Effect of kava (Piper methysticum) on peripheral gene expression among individuals with generalized anxiety disorder: A post hoc analysis of a randomized controlled trial.

Kava is a South Pacific plant-based medicine with anxiolytic properties, but little is known about the impact kava has on gene expression or whether gene expression can serve as a marker of kava response. This study aimed to determine whether kava treatment alters the expression of genes with physiological relevance to anxiety pathophysiology and whether the baseline expression of these physiologically relevant genes modifies the efficacy of kava treatment. In this post hoc analysis, we examined the expression of 48 genes relevant to the pathophysiology of anxiety collected from a double-blind randomized controlled trial that assessed the efficacy of kava treatment in generalized anxiety disorder. Peripheral blood gene expression was measured in 71 (34 kava, 37 placebo) adults at baseline and in 40 (19 kava, 21 placebo) after 8 weeks of treatment by reverse transcription polymerase chain reaction (PCR). Results revealed that kava decreased the expression of a subunit of the GABAA -rho receptor gene (GABRR2) and catechol-O-methyltransferase (COMT), a gene related to catecholamine metabolism. Kava efficacy was not found to be modified by baseline (pretreatment) expression of relevant genes. Although these results did not withstand statistical correction for multiple comparisons and require external validation, they support the notion that kava's mechanism of action includes interaction with GABAergic and catecholaminergic systems.

Longitudinal follow up of data-driven cognitive subtypes in Parkinson's disease.

AIM: The dual syndrome hypothesis proposes that there are two cognitive subtypes in Parkinson's disease (PD): a frontal subtype with executive/attention impairment and gradual cognitive decline, and a posterior-cortical subtype with memory/visuospatial deficits and rapid cognitive decline. We aimed to compare the rate of global cognitive decline between subtypes derived using data-driven methods and explore their longitudinal performance within specific cognitive domains to better understand the prognosis of each subtype. METHOD: Frontal, posterior-cortical, globally impaired, and cognitively intact PD subtypes were identified at baseline using k-means clustering (N = 85), and 29 participants (34%) returned for follow-up assessments on average 4.87 years from baseline. Linear mixed effects models compared progression of subtypes on global cognition; psychological symptoms; parkinsonism; and the memory, attention, executive, language, and visuospatial cognitive domains. RESULTS: The frontal subtype was lost to attrition. While rate of change in parkinsonism, anxiety, and apathy differed between subtypes, there was no difference in the rate of global cognitive decline. However, the posterior-cortical subtype declined most rapidly in verbal memory, card sorting, trail making, and judgement of line orientation (JLO), while the cognitively intact group declined most rapidly on verbal memory and semantic fluency. The globally impaired subtype declined most rapidly in JLO, although this should be interpreted with caution due to high attrition. CONCLUSION: Despite limited sample size, the present study supports the differential progression of the posterior-cortical subtype compared to cognitively intact and globally impaired PD. These results encourage further, large-scale longitudinal investigations of cognitive subtypes in PD.

A single-blind, parallel-group randomised trial of a Technology-assisted and remotely delivered Cognitive Behavioural Therapy intervention (Tech-CBT) versus usual care to reduce anxiety in people with mild cognitive impairment and dementia: study protocol for a randomised trial.

BACKGROUND: Anxiety is commonly experienced by people living with mild cognitive impairment (MCI) and dementia. Whilst there is strong evidence for late-life anxiety treatment using cognitive behavioural therapy (CBT) and delivery via telehealth, there is little evidence for the remote delivery of psychological treatment for anxiety in people living with MCI and dementia. This paper reports the protocol for the Tech-CBT study which aims to investigate the efficacy, cost-effectiveness, usability and acceptability of a technology-assisted and remotely delivered CBT intervention to enhance delivery of anxiety treatment for people living with MCI and dementia of any aetiology. METHODS: A hybrid II single-blind, parallel-group randomised trial of a Tech-CBT intervention (n = 35) versus usual care (n = 35), with in-built mixed methods process and economic evaluations to inform future scale-up and implementation into clinical practice. The intervention (i) consists of six weekly sessions delivered by postgraduate psychology trainees via telehealth video-conferencing, (ii) incorporates voice assistant app technology for home-based practice, and (iii) utilises a purpose-built digital platform, My Anxiety Care. The primary outcome is change in anxiety as measured by the Rating Anxiety in Dementia scale. Secondary outcomes include change in quality of life and depression, and outcomes for carers. The process evaluation will be guided by evaluation frameworks. Qualitative interviews will be conducted with a purposive sample of participants (n = 10) and carers (n = 10), to evaluate acceptability and feasibility, as well as factors influencing participation and adherence. Interviews will also be conducted with therapists (n = 18) and wider stakeholders (n = 18), to explore contextual factors and barriers/facilitators to future implementation and scalability. A cost-utility analysis will be undertaken to determine the cost-effectiveness of Tech-CBT compared to usual care. DISCUSSION: This is the first trial to evaluate a novel technology-assisted CBT intervention to reduce anxiety in people living with MCI and dementia. Other potential benefits include improved quality of life for people with cognitive impairment and their care partners, improved access to psychological treatment regardless of geographical location, and upskilling of the psychological workforce in anxiety treatment for people living with MCI and dementia. TRIAL REGISTRATION: This trial has been prospectively registered with ClinicalTrials.gov: NCT05528302 [September 2, 2022].

Global assessment, cognitive profile, and characteristics of mild cognitive impairment in Parkinson's disease.

BACKGROUND: Cognitive deficits are evident throughout the course of Parkinson's disease (PD), with 24% of patients experiencing subtle cognitive disturbances at the time of diagnosis, and with up to 80% of patients developing PD dementia (PDD) at advanced stages of the disease PD patients with mild cognitive impairment (MCI), an at-risk phenotype of PDD, present with heterogeneous clinical characteristics that complicate the management of PD. OBJECTIVES: This study aims to examine the characteristics of PD-MCI by using the Movement Disorder Society (MDS) diagnostic criteria and evaluate the validity of global cognitive scales in identifying PD-MCI. METHODS: Seventy-nine (79) PD patients completed neuropsychological assessments and a comprehensive cognitive battery. PD-MCI was classified according to the level 2 MDS task force criteria. Mini-Mental State Examination (sMMSE), Montreal Cognitive Assessment (MoCA) and Parkinson's Disease Cognitive Rating Scale (PDCRS) were examined against a level 2 dichotomised PD-MCI diagnosis. Characteristics of PD-MCI were evaluated using logistic regression analysis. RESULTS: Twenty-seven patients met criteria for PD-MCI (34%). The MoCA and PDCRS demonstrated high validity to screen for PD-MCI. Impairments in multiple cognitive domains were observed in 77.8% of PD-MCI patients. There were significantly more males in the PD-MCI group compared to PD patients without MCI (p < 0.01). CONCLUSIONS: PD patients with MCI exhibited impairments in the attention/working memory, executive function and memory domains. Heterogeneous cognitive characteristics in PD warrant further investigation into specific cognitive subtypes to advance understanding and effective evaluation of PD-MCI.

Feasibility and preliminary results of a call centre delivered continuing care intervention following residential alcohol and other drug treatment.

INTRODUCTION: To help reduce relapse rates following alcohol and other drug (AOD) treatment, continuing care interventions have been recommended. Previous continuing care interventions have incorporated telephone and face-to-face sessions to help promote participant engagement. The study was conducted as a randomised controlled feasibility study and examined a call centre delivered continuing care intervention for people leaving residential rehabilitation services. METHODS: Participants were attending AOD residential treatment services in NSW, Australia (N = 154). Participants were randomised to either 12- or 4-sessions of continuing care. Follow up assessments were completed at 6-months. The primary outcomes were demand and implementation. Secondary outcomes were AOD use, mental health and physical health at 6-months. RESULTS: Interest in continuing care was high, with 93% of participants approached reporting an interest in being involved. Of the participants who completed the consent and baseline procedures, 29% of people were contacted post residential treatment and randomised. For those people randomised, the average number of sessions completed was 2.78 (SD = 1.65) for the 4-session arm and 4.81 (SD = 4.46) for the 12-session arm. Fidelity to the treatment manual was high. Both treatment arms showed higher complete abstinence at 6-months compared to baseline (12-session OR 28.57 [2.3, 353.8]; 4-session OR 28.11 [3.6, 221.2]). DISCUSSION AND CONCLUSIONS: A major challenge associated with the call centre approach was re-engaging participants once they left the residential facility and delivering the planned dose of treatment. Further work is required to promote greater uptake of these protocols once people leave residential treatment.

Interventions for generalized anxiety disorder.

PURPOSE OF REVIEW: To provide an overview of recently published work on anxiety, focusing on generalized anxiety disorder (GAD) and its treatment. RECENT FINDINGS: Self-reported anxiety symptoms were highly prevalent during the COVID-19 global pandemic in both the general population and in selected groups. There remains divided opinion about whether internet-based cognitive behavioural therapy (CBT) is noninferior to face-to-face CBT for GAD. A systematic review of drug treatment for GAD showed efficacy for selective serotonin reuptake inhibitors (SNRIs), agomelatine, and quetiapine. There may be a place for repetitive transcranial magnetic stimulation in the treatment of GAD. There was some evidence of efficacy for complementary therapies, including physical exercise, yoga, acupuncture, and Withania somnifera (ashwagandha). However, a systematic review of cannabidiol and tetrahydrocannabinol found insufficient evidence of efficacy in anxiety disorders. SUMMARY: Antidepressants and quetiapine show efficacy in the treatment of GAD. Internet-based psychological interventions have a place in the treatment of GAD when face-to-face treatment is inaccessible. There is increasing evidence for the use of physical exercise in the management of GAD. Some other complementary therapies, including cannabinoids, require further, methodologically sound, research.

The Use of Balanced Scorecards in Mental Health Services: an Integrative Review and Thematic Analysis.

Performance management of mental health services (MHS) through quality reporting of strategic indicators and goals is essential to improve efficiency and quality of care. One such method is the balanced scorecard (BSC). This integrative review of peer-reviewed and industry implemented BSCs in MHS aims to inform future development of a more comprehensive mental health-focused benchmarking tool. A two-part systematic literature search consisted of peer-reviewed published literature on MHS specific BSCs utilising the PRISMA guidelines in addition to industry published BSCs available online. A total of 17 unique BSCs were identified. A total of 434 indicators were subject to thematic analysis identifying 11 key themes: prevalence, accessibility, services provided, clinical outcomes, client satisfaction, client involvement, staff motivation, staffing levels, governance and compliance, development, and costs and revenue. These themes represented the measures that MHS believed measured key performance criteria in alignment with their organisational objectives.

Frequency of changed behaviours in residential aged care and common mitigation strategies - A retrospective review of behavioural report logs.

BACKGROUND: Changed behaviours in residential aged care facilities (RACF) are frequently reported in the literature. How RACF staff routinely respond to these observed changed behaviours represents a significant gap. OBJECTIVE: To analyse the frequency of changed behaviour reported within RACF behavioural report logs and to ascertain how staff typically manage these behaviours. METHODS: Residents (N = 25) with varying levels of cognitive function were recruited from a 160 bed RACF in Queensland, Australia. A retrospective analysis of behavioural report logs was conducted to elucidate prevalence of reported changed behaviours as categorised by RACF staff. Thematic analysis of staff recorded behavioural mitigation strategies was used to categorise staff actions. A case analysis was also conducted to highlight the challenges faced by RACF staff managing persistent acute changed behaviours using identified common mitigation strategies. The STROBE guidelines were followed for reporting. RESULTS: There were 395 behaviours recorded in a two-month period. Physical agitation, interfering while wandering, trying to get to inappropriate places, verbal refusal of care, physical aggression, and verbal disruption were most frequently reported by staff. Management strategies included redirection, PRN psychotropic medication, reassurance, routine care practices, offering of beverages, repositioning, and rarely analgesia. A 24-h case analysis highlighted how staff utilised redirection and multiple doses of a PRN benzodiazepine with limited effectiveness. CONCLUSION: This study reveals current mitigation strategies employed by RACF staff in response to acute changed behaviours often associated with dementia. Agitation and wandering are prevalent and are difficult for staff to manage effectively. RELEVANCE TO CLINICAL PRACTICE: This study highlights that careful consideration should be taken to avoid overuse of PRN benzodiazepines in management of changed behaviours. Short-term mitigation strategies, such as redirection, may not be effective if underlying causes such as pain, physiological, mental, emotional, or social needs are not met. PATIENT AND PUBLIC CONTRIBUTION: A RACF participated in project design and review.

Phenomenology of anxiety in people living with mild to moderate dementia: A conceptual meta-ethnographic review.

OBJECTIVES: This conceptual review aims to integrate findings from published qualitative studies focusing on individual experiences of people living with dementia to generate a better understanding and conceptualisation of anxiety in dementia, including its subclinical manifestations. The review aims to inform the clinical practice to facilitate the development of targeted psychological interventions and provision of holistic support to people living with dementia. DESIGN: The review was conducted according to the guide for reporting meta-ethnographic qualitative syntheses eMERGe and the PRISMA guidelines. RESULTS: The search yielded a total of 2947 studies, out of which 13 were included in the final qualitative synthesis. The interpretive synthesis identified common experiences of people living with mild to moderate dementia, characterised by clusters of themes around worry, emotional experiences, and behavioural reactions in response to the diagnosis of dementia and its symptoms. These represent the components of a conceptual framework of anxiety in mild to moderate dementia, where anxiety is triggered by negative appraisals of living with an irreversible neurodegenerative disease. Stemming from these appraisals of dementia progression and its impact on the person's overall future, the content of worrisome thoughts and concerns include the loss of self and identity, losing independence and the ability to perform previous activities, concerns about being a burden to loved ones, and worry about the impact on interpersonal relationships. CONCLUSION: This conceptualisation of anxiety in dementia, including its subclinical manifestations facilitates the development of psychological interventions and provision of holistic support to people living with dementia.

Systematic review of data-driven cognitive subtypes in Parkinson disease.

BACKGROUND AND PURPOSE: Recent application of the mild cognitive impairment concept to Parkinson disease (PD) has proven valuable in identifying patients at risk of dementia. However, it has sparked controversy regarding the existence of cognitive subtypes. The present review evaluates the current literature pertaining to data-driven subtypes of cognition in PD. METHODS: Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, systematic literature searches for peer-reviewed articles on the topic of cognitive subtyping in PD were performed. RESULTS: Twenty-two relevant articles were identified in the systematic search. Subtype structures showed either a spectrum of severity or specific domains of impairment. Domain-specific subtypes included amnestic/nonamnestic, memory/executive, and frontal/posterior dichotomies, as well as more complex structures with less definitive groupings. Preliminary longitudinal evidence showed some differences in cognitive progression among subtypes. Neuroimaging evidence provided insight into distinct patterns of brain alterations among subtypes. CONCLUSIONS: Recurring phenotypes in the literature suggest strong clinical relevance of certain cognitive subtypes in PD. Although the current literature is limited, it raises critical questions about the utility of data-driven methods in cognitive research. The results encourage further integration of neuroimaging research to define the latent neural mechanisms behind divergent subtypes. Although there is no consensus, there appears to be growing consistency and inherent value in identifying cognitive subtypes in PD.

Semantic fluency deficits and associated brain activity in Parkinson's disease with mild cognitive impairment.

People living with Parkinson's disease (PD) with poor verbal fluency have an increased risk of developing dementia. This study examines the neural mechanisms underpinning semantic fluency deficits in patients with PD with mild cognitive impairment (PD-MCI) compared to those without MCI (PD-NC) and control participants without PD (non-PD). Thirty-seven (37) participants with PD completed a cognitive assessment battery to identify MCI (13 PD-MCI). Twenty sex- and age-matched non-PD patients also participated. Participants were scanned (3T Siemens PRISMA) while performing semantic fluency, semantic switching, and automatic speech tasks. The number of responses and fMRI data for semantic generation and semantic switching were analyzed. Participants also completed a series of verbal fluency tests outside the scanner, including letter fluency. Participants with PD-MCI performed significantly worse than PD-NC and non-PD participants during semantic fluency and semantic switching tasks. PD-MCI patients showed greater activity in the right angular gyrus than PD-NC and non-PD patients during semantic switching. Increased right angular activity correlated with worse verbal fluency performance outside the scanner. Our study showed that the PD-MCI group performed worse on semantic fluency than either the PD-NC or non-PD groups. Increased right angular gyrus activity in participants with PD-MCI during semantic switching suggests early compensatory mechanisms, predicting the risk of future dementia in PD.