Neuropsychiatric Symptoms in Behavioral Variant Frontotemporal Dementia and Alzheimer's Disease: A 12-Month Follow-Up Study

The pursuit for markers of disease progression in behavioral variant frontotemporal dementia: a scoping review to optimize outcome measures for clinical trials

Behavioral variant frontotemporal dementia (bvFTD) is a neurodegenerative disorder characterized by diverse and prominent changes in behavior and personality. One of the greatest challenges in bvFTD is to capture, measure and predict its disease progression, due to clinical, pathological and genetic heterogeneity. Availability of reliable outcome measures is pivotal for future clinical trials and disease monitoring. Detection of change should be objective, clinically meaningful and easily assessed, preferably associated with a biological process. The purpose of this scoping review is to examine the status of longitudinal studies in bvFTD, evaluate current assessment tools and propose potential progression markers. A systematic literature search (in PubMed and Embase.com) was performed. Literature on disease trajectories and longitudinal validity of frequently-used measures was organized in five domains: global functioning, behavior, (social) cognition, neuroimaging and fluid biomarkers. Evaluating current longitudinal data, we propose an adaptive battery, combining a set of sensitive clinical, neuroimaging and fluid markers, adjusted for genetic and sporadic variants, for adequate detection of disease progression in bvFTD.

Utility of the INECO Frontal Screening and the Frontal Assessment Battery in detecting executive dysfunction in early-onset cognitive impairment and dementia

OBJECTIVE

The INECO Frontal Screening (IFS) and the Frontal Assessment Battery (FAB) are executive dysfunction (ED) screening tools that can distinguish patients with neurodegenerative disorders from healthy controls and, to some extent, between dementia subtypes. This paper aims to examine the suitability of these tests in assessing early-onset cognitive impairment and dementia patients.

METHOD

In a memory clinic patient cohort (age mean = 57.4 years) with symptom onset at ≤65 years, we analyzed the IFS and the FAB results of four groups: early-onset dementia (EOD, n = 49), mild cognitive impairment due to neurological causes (MCI-n, n = 34), MCI due to other causes such as depression (MCI-o, n = 99) and subjective cognitive decline (SCD, n = 14). Data were gathered at baseline and at 6 and 12 months. We also studied the tests' accuracy in distinguishing EOD from SCD patients and ED patients from those with intact executive functioning. Correlations with neuropsychological measures were also studied.

RESULTS

The EOD group had significantly (p < .05) lower IFS and FAB total scores than the MCI-o and SCD groups. Compared with the FAB, the IFS showed more statistically significant (p < .05) differences between diagnostic groups, greater accuracy (IFS AUC = .80, FAB AUC = .75, p = .036) in detecting ED and marginally stronger correlations with neuropsychological measures. We found no statistically significant differences in the EOD group scores from baseline up to 6- or 12-months follow-up.

CONCLUSIONS

While both tests can detect EOD among memory clinic patients, the IFS may be more reliable in detecting ED than the FAB.

Identifying and Diagnosing TDP-43 Neurodegenerative Diseases in Psychiatry

Neuropsychiatric symptoms (NPS) are common manifestations of neurodegenerative disorders and are often early signs of those diseases. Among those neurodegenerative diseases, TDP-43 proteinopathies are an increasingly recognized cause of early neuropsychiatric manifestations. TDP-43-related diseases include frontotemporal dementia (FTD), amyotrophic lateral sclerosis (ALS), and Limbic-Predominant Age-Related TDP-43 Encephalopathy (LATE). The majority of TDP-43-related diseases are sporadic, but a significant proportion is hereditary, with progranulin (GRN) mutations and C9orf72 repeat expansions as the most common genetic etiologies. Studies reveal that NPS can be the initial manifestation of those diseases or can complicate disease course, but there is a lack of awareness among clinicians about TDP-43-related diseases, which leads to common diagnostic mistakes or delays. There is also emerging evidence that TDP-43 accumulations could play a role in late-onset primary psychiatric disorders. In the absence of robust biomarkers for TDP-43, the diagnosis remains primarily based on clinical assessment and neuroimaging. Given the association with psychiatric symptoms, clinical psychiatrists have a key role in the early identification of patients with TDP-43-related diseases. This narrative review provides a comprehensive overview of the pathobiology of TDP-43, resulting clinical presentations, and associated neuropsychiatric manifestations to help guide clinical practice.

Weight Change and Neuropsychiatric Symptoms in Alzheimer's Disease and Frontotemporal Dementia: Associations with Cognitive Decline

Weight changes, neuropsychiatric symptoms (NPS), and cognitive decline often coincide in Alzheimer's disease (AD) and frontotemporal dementia (FTD); however, the direction of their relationship remains unclear. This study aims to clarify the connection between weight changes, NPS, and cognition in AD and FTD. We found that cognitive decline was associated with decreased body mass index (BMI) in AD, while BMI gain was associated with increased conversion to FTD. Elevated NPS were associated with decreased BMI in AD and increased BMI in FTD. Identifying early changes in NPS and BMI may facilitate the detection of cognitive decline, providing an opportunity for early intervention.

Addition of the FTD Module to the Neuropsychiatric Inventory improves classification of frontotemporal dementia spectrum disorders

Most neuropsychiatric symptoms (NPS) common in frontotemporal dementia (FTD) are currently not part of the Neuropsychiatric Inventory (NPI). We piloted an FTD Module that included eight extra items to be used in conjunction with the NPI. Caregivers of patients with behavioural variant FTD (n = 49), primary progressive aphasia (PPA; n = 52), Alzheimer's dementia (AD; n = 41), psychiatric disorders (n = 18), presymptomatic mutation carriers (n = 58) and controls (n = 58) completed the NPI and FTD Module. We investigated (concurrent and construct) validity, factor structure and internal consistency of the NPI and FTD Module. We performed group comparisons on item prevalence, mean item and total NPI and NPI with FTD Module scores, and multinomial logistic regression to determine its classification abilities. We extracted four components, together explaining 64.1% of the total variance, of which the largest indicated the underlying dimension 'frontal-behavioural symptoms'. Whilst apathy (original NPI) occurred most frequently in AD, logopenic and non-fluent variant PPA, the most common NPS in behavioural variant FTD and semantic variant PPA were loss of sympathy/empathy and poor response to social/emotional cues (part of FTD Module). Patients with primary psychiatric disorders and behavioural variant FTD showed the most severe behavioural problems on both the NPI as well as the NPI with FTD Module. The NPI with FTD Module correctly classified more FTD patients than the NPI alone. By quantifying common NPS in FTD the NPI with FTD Module has large diagnostic potential. Future studies should investigate whether it can also prove a useful addition to the NPI in therapeutic trials.

Chain Mediation Analysis of the Effects of Nutrition and Cognition on the Association of Apolipoprotein E ɛ4 with Neuropsychiatric Symptoms in Alzheimer's Disease

BACKGROUND

Apolipoprotein E (APOE) is the most recognized risk gene for cognitive decline and clinical progression of late-onset Alzheimer's disease (AD); nonetheless, its association with neuropsychiatric symptoms (NPSs) remains inconclusive.

OBJECTIVE

To investigate the association of APOE ɛ4 with NPSs and explore nutritional status and cognition as joint mediators of this association.

METHODS

Between June 2021 and October 2022, patients with amnestic mild cognitive impairment (aMCI) or AD were recruited from the Chinese Imaging, Biomarkers, and Lifestyle Study. NPSs were assessed using the Neuropsychiatric Inventory, while global cognition and nutritional status were evaluated using the Mini-Mental State Examination (MMSE) and Mini-Nutritional Assessment (MNA), respectively. Simple mediation and multiple chain mediation models were developed to examine the mediating effects of the MNA and MMSE scores on the relationship between APOE ɛ4 and specific neuropsychiatric symptom.

RESULTS

Among 310 patients, 229 (73.87%) had NPSs, and 110 (35.48%) carried APOE ɛ4. Patients with APOE ɛ4 were more likely to have hallucinations (p = 0.014), apathy (p = 0.008), and aberrant motor activity (p = 0.018). MNA and MMSE scores mediated the association between APOE ɛ4 and hallucinations (17.97% and 37.13%, respectively), APOE ɛ4 and apathy (30.73% and 57.72%, respectively), and APOE ɛ4 and aberrant motor activity (17.82% and 34.24%), respectively. Chain-mediating effects of MNA and MMSE scores on the association of APOE ɛ4 with hallucinations, apathy, and aberrant motor activity after adjusting for confounding factors were 6.84%, 11.54%, and 6.19%, respectively.

CONCLUSION

Nutritional status and cognition jointly mediate the association between APOE ɛ4 and neuropsychiatric symptoms in patients with aMCI or AD.

Hyperorality in Frontotemporal Dementia: Cognitive and Psychiatric Symptom Profiles in Early-Stage Disease

Hyperorality is a distinctive feature of the behavioral variant of frontotemporal dementia (bvFTD), but little is known about its significance in early-stage disease. This study examined the cognitive and psychiatric symptom profiles associated with hyperorality, using data from subjects with early-stage bvFTD enrolled in Alzheimer's Disease Research Centers. We found that hyperorality was not associated with cognitive performance, but was associated with psychosis, elation, and disinhibition. Hyperorality may share neurobiology with a subset of early psychiatric symptoms, a finding which could help identify targets for future treatment.