Which older adults are at highest risk of prescribing cascades? A national study of the gabapentinoid-loop diuretic cascade

BACKGROUND

Prescribing cascades are important contributors to polypharmacy. Little is known about which older adults are at highest risk of experiencing prescribing cascades. We explored which older veterans are at highest risk of the gabapentinoid (including gabapentin and pregabalin)-loop diuretic (LD) cascade, given the dramatic increase in gabapentinoid prescribing in recent years.

METHODS

Using Veterans Affairs and Medicare claims data (2010-2019), we performed a prescription sequence symmetry analysis (PSSA) to assess loop diuretic initiation before and after gabapentinoid initiation among older veterans (≥66 years). To identify the cascade, we calculated the adjusted sequence ratio (aSR), which assesses the temporality of LD relative to gabapentinoid initiation. To explore high-risk groups, we used multivariable logistic regression with prescribing order modeled as a binary dependent variable. We calculated adjusted odds ratios (aORs), measuring the extent to which factors are associated with one prescribing order versus another.

RESULTS

Of 151,442 veterans who initiated a gabapentinoid, there were 1,981 patients who initiated a LD within 6 months after initiating a gabapentinoid compared to 1,599 patients who initiated a LD within 6 months before initiating a gabapentinoid. In the gabapentinoid-LD group, the mean age was 73 years, 98% were male, 13% were Black, 5% were Hispanic, and 80% were White. Patients in each group were similar across patient and health utilization factors (standardized mean difference <0.10 for all comparisons). The aSR was 1.23 (95% CI: 1.13, 1.34), strongly suggesting the cascade's presence. People age ≥85 years were less likely to have the cascade (compared to 66-74 years; aOR 0.74, 95% CI: 0.56-0.96), and people taking ≥10 medications were more likely to have the cascade (compared to 0-4 drugs; aOR 1.39, 95% CI: 1.07-1.82).

CONCLUSIONS

Among older adults, those who are younger and taking many medications may be at higher risk of the gabapentinoid-LD cascade, contributing to worsening polypharmacy and potential drug-related harms. We did not identify strong predictors of this cascade, suggesting that prescribing cascade prevention efforts should be widespread rather than focused on specific subgroups.

Secular Trends in Central Nervous System-Active Polypharmacy Among Serial Cross-Sections of US Adults, 2009-2020

BACKGROUND

Data comprehensively examining trends in central nervous system (CNS)-active polypharmacy are limited. The objective of this cross-sectional study was to characterize the composition of and trends in CNS-active medication use in US adults.

METHODS

We included all participants ≥ 18 years old in the National Health and Nutrition Examination Study (NHANES), 2009-2020. The primary outcome was the percent of adults with CNS-active polypharmacy. This was defined as ≥ 3 medications among antidepressants [tricyclic, selective and serotonin-norepinephrine reuptake inhibitors (SSRIs and SNRIs), opioids, antiepileptics, antipsychotics, benzodiazepines, and nonbenzodiazepine receptor agonists ("Z-drugs")]. Secondary outcomes included prevalence of any CNS-active medication and specific medications and classes over time, and their indications. Percentages were weighted according to NHANES's nationally representative sampling frame. log binomial regressions evaluated the relative risk (RR) for each outcome, comparing the last (2017-2020) versus the first (2010-2011) survey cycle.

RESULTS

We included 34,189 adults (18.8% at least 65 years old) from five serial cross-sections (survey cycles). The prevalence of CNS-active polypharmacy was 2.1% in 2009-2010 and 2.6% in 2017-2020 [RR 1.18, 95% confidence interval (CI) 0.94-1.47]. The prevalence of CNS-active polypharmacy did not significantly change within any specific age group (e.g., age at least 65 years: RR 1.29, CI 0.74-2.24). The prevalence of any CNS-active medication was 21.0% in 2009 and 24.6% in 2017-2020 (RR] 1.12, 95% CI 1.02-1.25). A substantial increase occurred for antiepileptics (5.1-8.3%), specifically among participants aged 65 years and older (8.3-13.7%). This was largely driven by increasing gabapentin prevalence (1.4-3.6% overall; 3.3-7.9% age 65 years and older). Anticholinergic, SSRIs/SNRIs, antiepileptics, and benzodiazepines were elevated in most cycles for participants at least 65 years old compared with participants less than 65 years, and opioid use was increased in several cycles for older participants as well. Alprazolam was the most common benzodiazepine and third most common medication for anxiety/depression. Gabapentin was the most common CNS-active medication (3.6% of all participants in 2017-2020), followed by sertraline, citalopram, and acetaminophen-hydrocodone (each ~2%). The most common categories were antidepressants (13.7% in 2017-2020), followed by opioids (5.1% in 2017-2020).

CONCLUSIONS

CNS-active medications are increasingly common, particularly gabapentin, and use of any CNS-active medication increased by 12%. Numerous CNS-active classes also increased in older adults throughout the years. Increasing suboptimal medication use highlight the need for further investigation into causes for potentially inappropriate prescribing, particularly for older adults.

Medication misuse and overuse in community-dwelling persons with dementia

BACKGROUND

Persons with dementia (PWD) have high rates of polypharmacy. While previous studies have examined specific types of problematic medication use in PWD, we sought to characterize a broad spectrum of medication misuse and overuse among community-dwelling PWD.

METHODS

We included community-dwelling adults aged ≥66 in the Health and Retirement Study from 2008 to 2018 linked to Medicare and classified as having dementia using a validated algorithm. Medication usage was ascertained over the 1-year prior to an HRS interview date. Potentially problematic medications were identified by: (1) medication overuse including over-aggressive treatment of diabetes/hypertension (e.g., insulin/sulfonylurea with hemoglobin A1c < 7.5%) and medications inappropriate near end of life based on STOPPFrail and (2) medication misuse including medications that negatively affect cognition and medications from 2019 Beers and STOPP Version 2 criteria. To contextualize, we compared medication use to people without dementia through a propensity-matched cohort by age, sex, comorbidities, and interview year. We applied survey weights to make our results nationally representative.

RESULTS

Among 1441 PWD, median age was 84 (interquartile range = 78-89), 67% female, and 14% Black. Overall, 73% of PWD were prescribed ≥1 potentially problematic medication with a mean of 2.09 per individual in the prior year. This was notable across several domains, including 41% prescribed ≥1 medication that negatively affects cognition. Frequently problematic medications included proton pump inhibitors (PPIs), non-steroidal anti-inflammatory drugs (NSAIDs), opioids, antihypertensives, and antidiabetic agents. Problematic medication use was higher among PWD compared to those without dementia with 73% versus 67% prescribed ≥1 problematic medication (p = 0.002) and mean of 2.09 versus 1.62 (p < 0.001), respectively.

CONCLUSION

Community-dwelling PWD frequently receive problematic medications across multiple domains and at higher frequencies compared to those without dementia. Deprescribing efforts for PWD should focus not only on potentially harmful central nervous system-active medications but also on other classes such as PPIs and NSAIDs.

One Step at a Time: Improving Gait Speed Measurement in a Geriatric Medicine Clinic

(1) Background: Mobility assessment is a key component of the assessment of an older adult as a part of the Age-Friendly Health System (AFHS) "geriatric 4Ms" framework. Several validated tools for assessing mobility and estimating fall risk in older adults are available. However, they are often under-utilized in daily practice even in specialty geriatric medicine care settings. We aimed to increase formal mobility assessment with brief gait speed measurement in a geriatric medicine outpatient clinic using phased change interventions. (2) Methods: This quality improvement (QI) initiative was conducted in a single outpatient geriatric medicine clinic. All clinic attendees who could complete a gait speed measurement were eligible for inclusion. The outcome measure was the completion of a 4 m gait speed. Several change interventions were implemented on a phased basis using the Model for Improvement methodology during the period from December 2018 to March 2020. Statistical process control charts were used to record gait speed measurements and detect non-random shifts. (3) Results: During this QI initiative, 80 patients were seen, accounting for 142 clinic visits. In response to change interventions, gait speed measurement at clinic visits increased from a median of 25% of visits to 67% by March 2020. (4) Conclusions: Adopting an AFHS care model is an urgent and challenging task to improve the quality of care for older adults. This initiative details how to effectively incorporate a brief, validated assessment of mobility using gait speed measurement into every geriatric medicine outpatient visit and progresses implementation of the AFHS "geriatric 4Ms". Mobility assessment can aid in identifying older adults at increased fall risk.

New psychotropic medication use among Medicare beneficiaries with dementia after hospital discharge

BACKGROUND

Hospitalizations among people with dementia (PWD) may precipitate behavioral changes, leading to the psychotropic medication use despite adverse outcomes and limited efficacy. We sought to determine the incidence of new psychotropic medication use among community-dwelling PWD after hospital discharge and, among new users, the proportion with prolonged use.

METHODS

This was a retrospective cohort study using a 20% random sample of Medicare claims in 2017, including hospitalized PWD with traditional and Part D Medicare who were 68 years or older. The primary outcome was incident prescribing at discharge of psychotropics including antipsychotics, sedative-hypnotics, antiepileptics, and antidepressants. This was defined as new prescription fills (i.e., from classes not used in 180 days preadmission) within 7 days of hospital or skilled nursing facility discharge. Prolonged use was defined as the proportion of new users who continued to fill newly prescribed medications beyond 90 days of discharge.

RESULTS

The cohort included 117,022 hospitalized PWD with a mean age of 81 years; 63% were female. Preadmission, 63% were using at least 1 psychotropic medication; 10% were using medications from ≥3 psychotropic classes. These included antidepressants (44% preadmission), antiepileptics (29%), sedative-hypnotics (21%), and antipsychotics (11%). The proportion of PWD discharged from the hospital with new psychotropics ranged from 1.9% (antipsychotics) to 2.9% (antiepileptics); 6.6% had at least one new class started. Among new users, prolonged use ranged from 36% (sedative-hypnotics) to 63% (antidepressants); across drug classes, prolonged use occurred in 51%. Predictors of newly initiated psychotropics included length of stay (≥median vs.

CONCLUSIONS

Hospitalized PWD have a high prevalence of preadmission psychotropic medication use; against this baseline, discharge from the hospital with new psychotropics is relatively uncommon. Nevertheless, prolonged use of newly initiated psychotropics occurs in a substantial proportion of this population.

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Key Words

• dementia
• hospitalization
• prescribing
• psychotropics

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MESH Headings

• Humans
• Female
• Aged
• United States
• Aged, 80 and over
• Male
• Patient Discharge
• Retrospective Studies
• Anticonvulsants/therapeutic use
• Dementia/drug therapy
• Medicare
• Psychotropic Drugs/therapeutic use
• Antipsychotic Agents/therapeutic use
• Antidepressive Agents/therapeutic use
• Hospitals
• Hypnotics and Sedatives/therapeutic use

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Grants

• K12 HS026383 AHRQ HHS
• L30 AG074160 NIA NIH HHS
• R24 AG064025 NIA NIH HHS
• K24 AG049057 NIA NIH HHS
• R35 AG071916 NIA NIH HHS
• R03 AG064373 NIA NIH HHS
• T32 AG000212 NIA NIH HHS
• P01 AG066605 NIA NIH HHS
• K01 AG073532 NIA NIH HHS
• P30 AG044281 NIA NIH HHS
• R03 AG078804 NIA NIH HHS

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Attitudes toward deprescribing among older adults with dementia in the United States

BACKGROUND

People with dementia (PWD) take medications that may be unnecessary or harmful. This problem can be addressed through deprescribing, but it is unclear if PWD would be willing to engage in deprescribing with their providers. Our goal was to investigate attitudes toward deprescribing among PWD.

METHODS

This was a cross-sectional study of 422 PWD aged ≥65 years who completed the medications attitudes module of the National Health and Aging Trends Study (NHATS) in 2016. Proxies provided responses when a participant was unable to respond due to health or cognitive problems. Attitudinal outcomes comprised responses to two statements from the patients' attitudes toward deprescribing questionnaire and its revised version (representing belief about the necessity of one's medications and willingness to deprescribe); another elicited the maximum number of pills that a respondent would be comfortable taking.

RESULTS

The weighted sample represented over 1.8 million PWD; 39% were 75 to 84 years old and 38% were 85 years or older, 60% were female, and 55% reported six or more regular medications. Proxies provided responses for 26% of PWD. Overall, 22% believed that they may be taking one or more medicines that they no longer needed, 87% were willing to stop one or more of their medications, and 50% were uncomfortable taking five or more medications. Attitudinal outcomes were similar across sociodemographic and clinical factors. PWD taking ≥6 medications were more likely to endorse a belief that at least one medication was no longer necessary compared to those taking <6 (adjusted probability 29% [95% confidence interval (CI), 22%-38%] vs. 13% [95% CI, 8%-20%]; p = 0.004); the same applied for willingness to deprescribe (92% [95% CI, 87%-95%] vs. 83% [95% CI, 76%-89%]; p = 0.04).

CONCLUSIONS

A majority of PWD are willing to deprescribe, representing an opportunity to improve quality of life for this vulnerable population.

Polypharmacy among older adults with dementia compared with those without dementia in the United States

BACKGROUND/OBJECTIVES

In older persons with dementia (PWD), extensive medication use is often unnecessary, discordant with goals of care, and possibly harmful. The objective of this study was to determine the prevalence and medication constituents of polypharmacy among older PWD attending outpatient visits in the United States.

DESIGN

Cross-sectional analysis.

SETTING AND PARTICIPANTS

PWD and persons without dementia (PWOD) aged ≥65 years attending outpatient visits recorded in the nationally representative National Ambulatory Medical Care Survey (NAMCS), 2014-2016.

MEASUREMENTS

PWD were identified as those with a diagnosis of dementia on the NAMCS encounter form and/or those receiving an anti-dementia medication. Visits with PWD and PWOD were compared in terms of sociodemographic, practice/physician factors, comorbidities, and prescribing outcomes. Regression analyses examined the effect of dementia diagnosis on contributions by clinically relevant medication categories to polypharmacy (defined as being prescribed ≥5 prescription and/or nonprescription medications).

RESULTS

The unweighted sample involved 918 visits for PWD and 26,543 visits for PWOD, representing 29.0 and 780 million outpatient visits. PWD had a median age of 81 and on average had 2.8 comorbidities other than dementia; 63% were female. The median number of medications in PWD was eight compared with three in PWOD (p < 0.001). After adjustment, PWD had significantly higher odds of being prescribed ≥5 medications (AOR 3.0; 95% CI: 2.1-4.3) or ≥10 medications (AOR 2.8; 95% CI: 2.0-4.2) compared with PWOD. The largest sources of medications among PWD were cardiovascular and central nervous system medications; usage from other categories was generally elevated in PWD compared with PWOD. PWD had higher odds of receiving at least one highly sedating or anticholinergic medication (AOR 2.5; 95% CI: 1.6-3.9).

CONCLUSION

In a representative sample of outpatient visits, polypharmacy was extremely common among PWD, driven by a wide array of medication categories. Addressing polypharmacy in PWD will require cross-cutting and multidisciplinary approaches.

Potential Medicare Savings From Generic Substitution and Therapeutic Interchange of ACE Inhibitors and Angiotensin-II-Receptor Blockers

This economic evaluation study estimates the potential Medicare savings from generic substitution and therapeutic interchange of brand-name hypertension medications.

Identification of Racial Inequities in Access to Specialized Inpatient Heart Failure Care at an Academic Medical Center

BACKGROUND

Racial inequities for patients with heart failure (HF) have been widely documented. HF patients who receive cardiology care during a hospital admission have better outcomes. It is unknown whether there are differences in admission to a cardiology or general medicine service by race. This study examined the relationship between race and admission service, and its effect on 30-day readmission and mortality Methods: We performed a retrospective cohort study from September 2008 to November 2017 at a single large urban academic referral center of all patients self-referred to the emergency department and admitted to either the cardiology or general medicine service with a principal diagnosis of HF, who self-identified as white, black, or Latinx. We used multivariable generalized estimating equation models to assess the relationship between race and admission to the cardiology service. We used Cox regression to assess the association between race, admission service, and 30-day readmission and mortality.

RESULTS

Among 1967 unique patients (66.7% white, 23.6% black, and 9.7% Latinx), black and Latinx patients had lower rates of admission to the cardiology service than white patients (adjusted rate ratio, 0.91; 95% CI, 0.84-0.98, for black; adjusted rate ratio, 0.83; 95% CI, 0.72-0.97 for Latinx). Female sex and age >75 years were also independently associated with lower rates of admission to the cardiology service. Admission to the cardiology service was independently associated with decreased readmission within 30 days, independent of race.

CONCLUSIONS

Black and Latinx patients were less likely to be admitted to cardiology for HF care. This inequity may, in part, drive racial inequities in HF outcomes.

Emotion detection deficits and changes in personality traits linked to loss of white matter integrity in primary progressive aphasia

Non-cognitive features including personality changes are increasingly recognized in the three PPA variants (semantic-svPPA, non fluent-nfvPPA, and logopenic-lvPPA). However, differences in emotion processing among the PPA variants and its association with white matter tracts are unknown. We compared emotion detection across the three PPA variants and healthy controls (HC), and related them to white matter tract integrity and cortical degeneration. Personality traits in the PPA group were also examined in relation to white matter tracts. Thirty-three patients with svPPA, nfvPPA, lvPPA, and 32 HC underwent neuropsychological assessment, emotion evaluation task (EET), and MRI scan. Patients' study partners were interviewed on the Clinical Dementia Rating Scale (CDR) and completed an interpersonal traits assessment, the Interpersonal Adjective Scale (IAS). Diffusion tensor imaging of uncinate fasciculus (UF), superior longitudinal fasciculus (SLF) and inferior longitudinal fasciculus (ILF), and voxel-based morphometry to derive gray matter volumes for orbitofrontal cortex (OFC), anterior temporal lobe (ATL) regions were performed. In addition, gray matter volumes of white matter tract-associated regions were also calculated: inferior frontal gyrus (IFG), posterior temporal lobe (PTL), inferior parietal lobe (IPL) and occipital lobe (OL). ANCOVA was used to compare EET performance. Partial correlation and multivariate linear regression were conducted to examine association between EET and neuroanatomical regions affected in PPA. All three variants of PPA performed significantly worse than HC on EET, and the svPPA group was least accurate at recognizing emotions. Performance on EET was related to the right UF, SLF, and ILF integrity. Regression analysis revealed EET performance primarily relates to the right UF integrity. The IAS subdomain, cold-hearted, was also associated with right UF integrity. Disease-specific emotion recognition and personality changes occur in the three PPA variants and are likely associated with disease-specific neuroanatomical changes. Loss of white matter integrity contributes as significantly as focal atrophy in behavioral changes in PPA.

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All three variants of PPA demonstrate emotion recognition impairment.

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The svPPA group exhibits the greatest emotion recognition deficit.

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Emotion recognition deficit is associated with the right UF integrity in PPA.

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Changes in certain personality traits are also related to right UF integrity in PPA.

The interface between delirium and dementia in elderly adults

Delirium and dementia are two of the most common causes of cognitive impairment in older populations, yet their interrelation remains poorly understood. Previous studies have shown that dementia is the leading risk factor for delirium and that delirium is an independent risk factor for subsequent development of dementia. However, a major area of controversy is whether delirium is simply a marker of vulnerability to dementia, whether the effect of delirium is solely related to its precipitating factors, or whether delirium itself can cause permanent neuronal damage and lead to dementia. Ultimately, all of these hypotheses are likely to be true. Emerging evidence from epidemiological, clinicopathological, neuroimaging, biomarker, and experimental studies lends support to a strong relation between delirium and dementia, and to both shared and distinct pathological mechanisms. New preventive and therapeutic approaches that target delirium might offer a sought-after opportunity for early intervention, preservation of cognitive reserve, and prevention of irreversible cognitive decline in ageing.

Odor identification and Alzheimer disease biomarkers in clinically normal elderly

OBJECTIVES

Our objective was to investigate cross-sectional associations between odor identification ability and imaging biomarkers of neurodegeneration and amyloid deposition in clinically normal (CN) elderly individuals, specifically testing the hypothesis that there may be an interaction between amyloid deposition and neurodegeneration in predicting odor identification dysfunction.

METHODS

Data were collected on 215 CN participants from the Harvard Aging Brain Study. Measurements included the 40-item University of Pennsylvania Smell Identification Test and neuropsychological testing, hippocampal volume (HV) and entorhinal cortex (EC) thickness from MRI, and amyloid burden using Pittsburgh compound B (PiB) PET. A linear regression model with backward elimination (p < 0.05 retention) evaluated the cross-sectional association between the University of Pennsylvania Smell Identification Test and amyloid burden, HV, and EC thickness, assessing for effect modification by PiB status. Covariates included age, sex, premorbid intelligence, APOE ε4 carrier status, and Boston Naming Test.

RESULTS

In unadjusted univariate analyses, worse olfaction was associated with decreased HV (p < 0.001), thinner EC (p = 0.003), worse episodic memory (p = 0.03), and marginally associated with greater amyloid burden (binary PiB status, p = 0.06). In the multivariate model, thinner EC in PiB-positive individuals (interaction term) was associated with worse olfaction (p = 0.02).

CONCLUSIONS

In CN elderly, worse odor identification was associated with markers of neurodegeneration. Furthermore, individuals with elevated cortical amyloid and thinner EC exhibited worse odor identification, elucidating the potential contribution of olfactory testing to detect preclinical AD in CN individuals.

Amyloid vs FDG-PET in the differential diagnosis of AD and FTLD

OBJECTIVE

To compare the diagnostic performance of PET with the amyloid ligand Pittsburgh compound B (PiB-PET) to fluorodeoxyglucose (FDG-PET) in discriminating between Alzheimer disease (AD) and frontotemporal lobar degeneration (FTLD).

METHODS

Patients meeting clinical criteria for AD (n = 62) and FTLD (n = 45) underwent PiB and FDG-PET. PiB scans were classified as positive or negative by 2 visual raters blinded to clinical diagnosis, and using a quantitative threshold derived from controls (n = 25). FDG scans were visually rated as consistent with AD or FTLD, and quantitatively classified based on the region of lowest metabolism relative to controls.

RESULTS

PiB visual reads had a higher sensitivity for AD (89.5% average between raters) than FDG visual reads (77.5%) with similar specificity (PiB 83%, FDG 84%). When scans were classified quantitatively, PiB had higher sensitivity (89% vs 73%) while FDG had higher specificity (83% vs 98%). On receiver operating characteristic analysis, areas under the curve for PiB (0.888) and FDG (0.910) were similar. Interrater agreement was higher for PiB (κ = 0.96) than FDG (κ = 0.72), as was agreement between visual and quantitative classification (PiB κ = 0.88-0.92; FDG κ = 0.64-0.68). In patients with known histopathology, overall classification accuracy (2 visual and 1 quantitative classification per patient) was 97% for PiB (n = 12 patients) and 87% for FDG (n = 10).

CONCLUSIONS

PiB and FDG showed similar accuracy in discriminating AD and FTLD. PiB was more sensitive when interpreted qualitatively or quantitatively. FDG was more specific, but only when scans were classified quantitatively. PiB slightly outperformed FDG in patients with known histopathology.

Clinicopathological correlations in corticobasal degeneration

OBJECTIVE

To characterize cognitive and behavioral features, physical findings, and brain atrophy patterns in pathology-proven corticobasal degeneration (CBD) and corticobasal syndrome (CBS) with known histopathology.

METHODS

We reviewed clinical and magnetic resonance imaging data in all patients evaluated at our center with either an autopsy diagnosis of CBD (n = 18) or clinical CBS at first presentation with known histopathology (n = 40). Atrophy patterns were compared using voxel-based morphometry.

RESULTS

CBD was associated with 4 clinical syndromes: progressive nonfluent aphasia (n = 5), behavioral variant frontotemporal dementia (n = 5), executive-motor (n = 7), and posterior cortical atrophy (n = 1). Behavioral or cognitive problems were the initial symptoms in 15 of 18 patients; less than half exhibited early motor findings. Compared to controls, CBD patients showed atrophy in dorsal prefrontal and perirolandic cortex, striatum, and brainstem (p < 0.001 uncorrected). The most common pathologic substrates for clinical CBS were CBD (35%), Alzheimer disease (AD, 23%), progressive supranuclear palsy (13%), and frontotemporal lobar degeneration (FTLD) with TDP inclusions (13%). CBS was associated with perirolandic atrophy irrespective of underlying pathology. In CBS due to FTLD (tau or TDP), atrophy extended into prefrontal cortex, striatum, and brainstem, whereas in CBS due to AD, atrophy extended into temporoparietal cortex and precuneus (p < 0.001 uncorrected).

INTERPRETATION

Frontal lobe involvement is characteristic of CBD, and in many patients frontal, not parietal or basal ganglia, symptoms dominate early stage disease. CBS is driven by medial perirolandic dysfunction, but this anatomy is not specific to a single underlying histopathology. Antemortem prediction of CBD will remain challenging until clinical features of CBD are redefined, and sensitive, specific biomarkers are identified.

Comprehension of insincere communication in neurodegenerative disease: lies, sarcasm, and theory of mind

Comprehension of insincere communication is an important aspect of social cognition requiring visual perspective taking, emotion reading, and understanding others' thoughts, opinions, and intentions. Someone who is lying intends to hide their insincerity from the listener, while a sarcastic speaker wants the listener to recognize they are speaking insincerely. We investigated whether face-to-face testing of comprehending insincere communication would effectively discriminate among neurodegenerative disease patients with different patterns of real-life social deficits. We examined ability to comprehend lies and sarcasm from a third-person perspective, using contextual cues, in 102 patients with one of four neurodegenerative diseases (behavioral variant frontotemporal dementia [bvFTD], Alzheimer's disease [AD], progressive supranuclear palsy [PSP], and vascular cognitive impairment) and 77 healthy older adults (normal controls--NCs). Participants answered questions about videos depicting social interactions involving deceptive, sarcastic, or sincere speech using The Awareness of Social Inference Test. All subjects equally understood sincere remarks, but bvFTD patients displayed impaired comprehension of lies and sarcasm compared with NCs. In other groups, impairment was not disease-specific but was proportionate to general cognitive impairment. Analysis of the task components revealed that only bvFTD patients were impaired on perspective taking and emotion reading elements and that both bvFTD and PSP patients had impaired ability to represent others' opinions and intentions (i.e., theory of mind). Test performance correlated with informants' ratings of subjects' empathy, perspective taking and neuropsychiatric symptoms in everyday life. Comprehending insincere communication is complex and requires multiple cognitive and emotional processes vulnerable across neurodegenerative diseases. However, bvFTD patients show uniquely focal and severe impairments at every level of theory of mind and emotion reading, leading to an inability to identify obvious examples of deception and sarcasm. This is consistent with studies suggesting this disease targets a specific neural network necessary for perceiving social salience and predicting negative social outcomes.

Divergent network connectivity changes in behavioural variant frontotemporal dementia and Alzheimer's disease

Resting-state or intrinsic connectivity network functional magnetic resonance imaging provides a new tool for mapping large-scale neural network function and dysfunction. Recently, we showed that behavioural variant frontotemporal dementia and Alzheimer's disease cause atrophy within two major networks, an anterior 'Salience Network' (atrophied in behavioural variant frontotemporal dementia) and a posterior 'Default Mode Network' (atrophied in Alzheimer's disease). These networks exhibit an anti-correlated relationship with each other in the healthy brain. The two diseases also feature divergent symptom-deficit profiles, with behavioural variant frontotemporal dementia undermining social-emotional function and preserving or enhancing visuospatial skills, and Alzheimer's disease showing the inverse pattern. We hypothesized that these disorders would exert opposing connectivity effects within the Salience Network (disrupted in behavioural variant frontotemporal dementia but enhanced in Alzheimer's disease) and the Default Mode Network (disrupted in Alzheimer's disease but enhanced in behavioural variant frontotemporal dementia). With task-free functional magnetic resonance imaging, we tested these ideas in behavioural variant frontotemporal dementia, Alzheimer's disease and healthy age-matched controls (n = 12 per group), using independent component analyses to generate group-level network contrasts. As predicted, behavioural variant frontotemporal dementia attenuated Salience Network connectivity, most notably in frontoinsular, cingulate, striatal, thalamic and brainstem nodes, but enhanced connectivity within the Default Mode Network. Alzheimer's disease, in contrast, reduced Default Mode Network connectivity to posterior hippocampus, medial cingulo-parieto-occipital regions and the dorsal raphe nucleus, but intensified Salience Network connectivity. Specific regions of connectivity disruption within each targeted network predicted intrinsic connectivity enhancement within the reciprocal network. In behavioural variant frontotemporal dementia, clinical severity correlated with loss of right frontoinsular Salience Network connectivity and with biparietal Default Mode Network connectivity enhancement. Based on these results, we explored whether a combined index of Salience Network and Default Mode Network connectivity might discriminate between the three groups. Linear discriminant analysis achieved 92% clinical classification accuracy, including 100% separation of behavioural variant frontotemporal dementia and Alzheimer's disease. Patients whose clinical diagnoses were supported by molecular imaging, genetics, or pathology showed 100% separation using this method, including four diagnostically equivocal 'test' patients not used to train the algorithm. Overall, the findings suggest that behavioural variant frontotemporal dementia and Alzheimer's disease lead to divergent network connectivity patterns, consistent with known reciprocal network interactions and the strength and deficit profiles of the two disorders. Further developed, intrinsic connectivity network signatures may provide simple, inexpensive, and non-invasive biomarkers for dementia differential diagnosis and disease monitoring.

Conflict monitoring in early frontotemporal dementia

BACKGROUND

Despite the extensive frontal atrophy and behavioral disinhibition that characterizes behavioral variant frontotemporal dementia (bvFTD), many studies of early bvFTD suggest normal executive functioning (EF). The current study examined cognitive control in patients with bvFTD who otherwise seemed cognitively normal.

METHODS

Subjects included 7 patients with bvFTD with normal neuropsychological test scores, 7 patients with bvFTD matched for Mini-Mental State Examination score but with impaired neuropsychological test scores, and 14 normal controls. A flanker paradigm and other measures of EF were administered to participants. A semiautomated parcellation program was used to analyze structural MRI scans.

RESULTS

On the flanker task, multivariate analysis of variance revealed a significant condition X diagnosis interaction. Both bvFTD groups showed a larger congruency effect than normal controls, i.e., they displayed disproportionately reduced speed and accuracy on incongruent trials relative to congruent trials. Imaging data illustrated significant orbitofrontal atrophy in patients with early bvFTD as compared with controls.

CONCLUSIONS

Patients with behavioral variant frontotemporal dementia (bvFTD) who performed within normal limits on clinical tests of executive functioning demonstrated a select impairment on an experimental test of cognitive control, suggesting a subtle impairment in inhibiting attention or response to the irrelevant stimuli. Measures of neuropsychological functioning sensitive to the ventromedial prefrontal cortex may be useful in early diagnosis of patients with bvFTD. Our understanding of this syndrome may be increased by considering the efficiency of selective inhibition, a fundamental component of executive cognitive control.

'The quicksand of forgetfulness': semantic dementia in One hundred years of solitude

This multidisciplinary article compares the pattern of memory loss described in Gabriel García Márquez's One Hundred Years of Solitude to that exhibited by patients with semantic dementia (SD). In his renowned novel, García Márquez depicts the plight of Macondo, a town struck by the dreaded insomnia plague. The most devastating symptom of the plague is not the impossibility of sleep, but rather the loss of 'the name and notion of things'. In an effort to combat this insidious loss of knowledge, the protagonist, José Arcadio Buendía, 'marked everything with its name: table, chair, clock, door, wall, bed, pan'. 'Studying the infinite possibilities of a loss of memory, he realized that the day might come when things would be recognized by their inscriptions but that no one would remember their use'. The cognitive impairments experienced by Macondo's inhabitants are remarkably similar to those observed in SD, a clinical syndrome characterized by a progressive breakdown of conceptual knowledge (semantic memory) in the context of relatively preserved day-to-day (episodic) memory. First recognized in 1975, it is now considered one of the main variants of frontotemporal lobar degeneration. Writing within the realm of magical realism and investigating the power of language as a form of communication, García Márquez provides beautiful descriptions of the loss of 'the name and notion of things' typical of the syndrome. He further speculates on ways to cope with this dissolution of meaning, ranging from 'the spell of an imaginary reality' to José Arcadio's 'memory machine', strategies that resonate with attempts by semantic dementia patients to cope with their disease. Remarkably, García Márquez created a striking literary depiction of collective semantic dementia before the syndrome was recognized in neurology. The novel also provides an inspiring and human account of one town's fight against 'the quicksand of forgetfulness'.