Perspectives on the diagnosis and management of functional cognitive disorder: An international Delphi study

BACKGROUND

Current proposed criteria for functional cognitive disorder (FCD) have not been externally validated. We sought to analyse the current perspectives of cognitive specialists in the diagnosis and management of FCD in comparison with neurodegenerative conditions.

METHODS

International experts in cognitive disorders were invited to assess seven illustrative clinical vignettes containing history and bedside characteristics alone. Participants assigned a probable diagnosis and selected the appropriate investigation and treatment. Qualitative, quantitative and inter-rater agreement analyses were undertaken.

RESULTS

Eighteen diagnostic terminologies were assigned by 45 cognitive experts from 12 countries with a median of 13 years of experience, across the seven scenarios. Accurate discrimination between FCD and neurodegeneration was observed, independently of background and years of experience: 100% of the neurodegenerative vignettes were correctly classified and 75%-88% of the FCD diagnoses were attributed to non-neurodegenerative causes. There was <50% agreement in the terminology used for FCD, in comparison with 87%-92% agreement for neurodegenerative syndromes. Blood tests and neuropsychological evaluation were the leading diagnostic modalities for FCD. Diagnostic communication, psychotherapy and psychiatry referral were the main suggested management strategies in FCD.

CONCLUSIONS

Our study demonstrates the feasibility of distinguishing between FCD and neurodegeneration based on relevant patient characteristics and history details. These characteristics need further validation and operationalisation. Heterogeneous labelling and framing pose clinical and research challenges reflecting a lack of agreement in the field. Careful consideration of FCD diagnosis is advised, particularly in the presence of comorbidities. This study informs future research on diagnostic tools and evidence-based interventions.

A Systematic Review and Meta-Analysis of the Association between Personality and Cognitive Failures / Complaints

This systematic review examined the associations of personality traits with cognitive failures and cognitive complaints across the adult lifespan. We first present three conceptual models (cognitive abilities, mental processes, and reporting bias) that could explain why personality is related to such behaviors. We then conducted five separate meta-analyses with 10-17 cross-sectional samples (N = 7,642 - 10,564) that were identified through a systematic literature search following the MOOSE guidelines. Higher neuroticism (r = .39, 95% CI [0.32, 0.45]) and lower conscientiousness (r = -.36, 95% CI [-.42, -.29]) were related to more cognitive failures and complaints. Lower scores on the remaining traits were also associated with more cognitive failures and complaints, yet to a weaker extent (extraversion: r = -.14, 95% CI [-.20, -.08]; openness: r = -.07, 95% CI [-.11, -.03]; agreeableness: r = -.13, 95% CI [-.21, -.05]). With the current empirical evidence, it is not possible to tell which of the three conceptual models explains how much of the associations. For neuroticism, there is more support for the mental processes than the reporting bias model, but more research is needed to fully test mechanistic models. We provide several suggestions for future research to address existing limitations of the literature on personality and cognitive failures and complaints.

Lifestyle Variables Do Not Predict Subjective Memory Performance Over and Above Depression and Anxiety

The diagnostic value of subjective cognitive complaints for cognitive functioning in a clinical setting remains unresolved today. However, consensus exists on the relation between subjective cognitive complaints (SCC) and mood variables such as anxiety and depression. Hence, SCC have also been discussed as potential proxies of psychopathology rather than representing cognitive functioning. In order to shed more light on yet still unexplained variance in subjective cognitive complaints, the relation between lifestyle variables (such as nutrition habits, exercise, alcohol consumption, smoking, quality of sleep, and Body Mass Index) and subjective complaints of selective attention as well as subjective memory performance were assessed, additionally to the influence of objective memory performance, measures of anxiety, and depression. A sample of 877 (554 women) healthy, middle-aged individuals (51 years on average, age range 35–65) was assessed in the present study. In a logistic regression framework results revealed that the effect of lifestyle variables on subjective complaints of selective attention as well as subjective memory performance was rendered non-significant. Instead, subjective complaints of selective attention and subjective memory performance were significantly determined by measures of both, anxiety and depression. One unit increase in anxiety or depression led to an increase of 6 or 15% in subjective memory performance complaints, respectively. For subjective complaints of selective attention, a one unit increase in anxiety or depression led to an increase of 11 or 26%, respectively. The strong relation between SCC and measures of depression and anxiety corroborates the notion of SCC being indicative of mental health and general well-being.

Talk the talk and walk the walk. Evaluation of autonomy in aging and Alzheimer disease by simulating instrumental activities of daily living: the S-IADL

Objective

The autonomy of individuals is linked to the achievement of instrumental activities of daily living that require complex behavior. In the elderly, the assessment of autonomy is usually based on questionnaires that have strong subjective constraints. Considering this fact, we tested elderly healthy adults and Alzheimer disease patients using a new measure, the S-IADL (Simulation of Instrumental Activities for Daily Living), to assess the ability to perform effectively activities of daily living.

Method

The S-IADL shares many items with the well-known IADL questionnaire proposed by Lawton & Brody (1969). However, as opposed to the IADL, the assessment of autonomy is not based on the completion of a questionnaire but requires the realization or simulation of various activities of daily living. Eighty-three participants (69 healthy elderly, and 14 Alzheimer Disease patients) completed the IADL and performed the S-IADL assessment.

Results

Results revealed that, like the IADL, the S-IADL is able to identify AD patients who are likely to encounter difficulties in performing everyday activities, and no major differences were found between the IADL and the S-IADL.

Conclusions

We outlined some advantages for prefering, in certain situation, this new tool based on simulation of activities in functional evaluation. Finally, we discuss the main limits of the S-IADL that should be investigated prior to its utilization by clinicians.

Subjective Cognitive Decline in Older Adults: An Overview of Self-Report Measures Used Across 19 International Research Studies

Research increasingly suggests that subjective cognitive decline (SCD) in older adults, in the absence of objective cognitive dysfunction or depression, may be a harbinger of non-normative cognitive decline and eventual progression to dementia. Little is known, however, about the key features of self-report measures currently used to assess SCD. The Subjective Cognitive Decline Initiative (SCD-I) Working Group is an international consortium established to develop a conceptual framework and research criteria for SCD (Jessen et al., 2014, Alzheimers Dement 10, 844-852). In the current study we systematically compared cognitive self-report items used by 19 SCD-I Working Group studies, representing 8 countries and 5 languages. We identified 34 self-report measures comprising 640 cognitive self-report items. There was little overlap among measures- approximately 75% of measures were used by only one study. Wide variation existed in response options and item content. Items pertaining to the memory domain predominated, accounting for about 60% of items surveyed, followed by executive function and attention, with 16% and 11% of the items, respectively. Items relating to memory for the names of people and the placement of common objects were represented on the greatest percentage of measures (56% each). Working group members reported that instrument selection decisions were often based on practical considerations beyond the study of SCD specifically, such as availability and brevity of measures. Results document the heterogeneity of approaches across studies to the emerging construct of SCD. We offer preliminary recommendations for instrument selection and future research directions including identifying items and measure formats associated with important clinical outcomes.

Self-Regulatory Strategies in Daily Life: Selection, Optimization, and Compensation and Everyday Memory Problems

The effective use of self-regulatory strategies, such as selection, optimization, and compensation (SOC) requires resources. However, it is theorized that SOC use is most advantageous for those experiencing losses and diminishing resources. The present study explored this seeming paradox within the context of limitations or constraints due to aging, low cognitive resources, and daily stress in relation to everyday memory problems. We examined whether SOC usage varied by age and level of constraints, and if the relationship between resources and memory problems was mitigated by SOC usage. A daily diary paradigm was used to explore day-to-day fluctuations in these relationships. Participants (n=145, ages 22 to 94) completed a baseline interview and a daily diary for seven consecutive days. Multilevel models examined between- and within-person relationships between daily SOC use, daily stressors, cognitive resources, and everyday memory problems. Middle-aged adults had the highest SOC usage, although older adults also showed high SOC use if they had high cognitive resources. More SOC strategies were used on high stress compared to low stress days. Moreover, the relationship between daily stress and memory problems was buffered by daily SOC use, such that on high-stress days, those who used more SOC strategies reported fewer memory problems than participants who used fewer SOC strategies. The paradox of resources and SOC use can be qualified by the type of resource-limitation. Deficits in global resources were not tied to SOC usage or benefits. Conversely, under daily constraints tied to stress, the use of SOC increased and led to fewer memory problems.

Subjective cognitive failures in patients with hypertension are related to cognitive performance and cerebral microbleeds

Previous studies on the relationship between subjective cognitive failures (SCF) and objective cognitive function have shown inconsistent results. In addition, research on the association between SCF and imaging markers of cerebral small vessel disease is limited. We investigated whether SCF in patients with essential hypertension, who are at high risk of cerebral small vessel disease, are associated with objective cognitive function and magnetic resonance imaging manifestations of cerebral small vessel disease. We included 109 patients with hypertension who underwent extensive neuropsychological assessment, including questionnaires measuring SCF and symptoms of anxiety and depression. Brain magnetic resonance imaging was performed to rate the presence of lacunes, cerebral microbleeds, and perivascular spaces, as well as white matter hyperintensities volume. Results showed significant associations between SCF and objectively measured overall cognition (B=-0.02; 95% confidence interval=-0.03 to -0.005), memory (B=0.02; 95% confidence interval=-0.03 to -0.004), and information processing speed (B=-0.02; 95% confidence interval=-0.03 to -0.001) after adjustment for patient characteristics and vascular risk factors. In addition, SCF were associated with the presence of cerebral microbleeds (odds ratio=1.12; 95% confidence interval=1.02-1.23) after adjustment for patient characteristics and vascular risk factors but not with other imaging markers of cerebral small vessel disease. Our study demonstrates that attention for SCF in patients with hypertension is needed because these may point to lower objective cognitive function, which might be as a result of the presence of cerebral microbleeds. Accordingly, this study emphasizes that neuropsychological assessment and brain imaging need to be considered when patients with hypertension report SCF.