Publications by authors named "Bruce L. Miller"

Importance: Individuals with tuberous sclerosis complex can develop a progressive neuropsychiatric syndrome known as tuberous sclerosis-associated neuropsychiatric disorders. Tuberous sclerosis-associated neuropsychiatric disorders symptoms overlap with clinical criteria for frontotemporal dementia, yet the association between the 2 has not been explored.

Objective: To investigate the potential association between tuberous sclerosis-associated neuropsychiatric disorders and frontotemporal dementia.

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Expressive suppression is a response-focused regulatory strategy aimed at concealing the outward expression of emotion that is already underway. Expressive suppression requires the integration of interoception, proprioception, and social awareness to guide behavior in alignment with personal and interpersonal goals-all processes known to involve the insular cortex. Frontotemporal dementia (FTD) provides a useful patient model for studying the insula's role in socioemotional regulation.

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Intrinsic connectivity networks (ICNs) identified through task-free fMRI (tf-fMRI) offer the opportunity to investigate human brain circuits involved in language processes without requiring participants to perform challenging cognitive tasks. In this study, we assessed the ability of tf-fMRI to isolate reproducible networks critical for specific language functions and often damaged in primary progressive aphasia (PPA). First, we performed whole-brain seed-based correlation analyses on tf-fMRI data to identify ICNs anchored in regions known for articulatory, phonological, and semantic processes in healthy male and female controls (HCs).

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Patients with Alzheimer's disease and other dementias often make poor financial decisions, but it remains unclear whether this reflects specific failures in decision-making or more general deficits in episodic and working memory. We investigated how patients with Alzheimer's disease, behavioral variant frontotemporal dementia (bvFTD), and semantic variant primary progressive aphasia (svPPA) apply information in an intertemporal choice task between smaller intermediate and larger delayed rewards, with minimal memory demands. Multilevel modeling estimated subject-level sensitivities to three attributes of choice (the relative difference in reward magnitude, delay length, and absolute reward magnitudes) as well as baseline impulsivity.

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Article Synopsis
  • The anterior insula (aINS) is divided into ventral and dorsal parts, with the ventral contributing to socio-emotional functions and the dorsal aiding cognitive processes through various brain connections.
  • Researchers developed a new method to study how the connectivity of aINS changes over time using advanced MRI techniques and analyzed data from healthy participants.
  • They discovered four key types of aINS connectivity that include both short-term (state) and long-term (trait) characteristics, with some connections being affected by eye closure and others remaining consistent, which are linked to levels of empathy.
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Introduction: The Advancing Research and Treatment in Frontotemporal Lobar Degeneration and Longitudinal Evaluation of Familial Frontotemporal Dementia Subjects longitudinal studies were designed to describe the natural history of familial-frontotemporal lobar degeneration due to autosomal dominant mutations.

Methods: We examined cognitive performance, behavioral ratings, and brain volumes from the first time point in 320 MAPT, GRN, and C9orf72 family members, including 102 non-mutation carriers, 103 asymptomatic carriers, 43 mildly/questionably symptomatic carriers, and 72 carriers with dementia.

Results: Asymptomatic carriers showed similar scores on all clinical measures compared with noncarriers but reduced frontal and temporal volumes.

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Background: Primary care providers (PCPs) are typically the first to screen and evaluate patients for neurocognitive disorders (NCDs), including mild cognitive impairment and dementia. However, data on PCP attitudes and evaluation and management practices are sparse. Our objective was to quantify perspectives and behaviors of PCPs and neurologists with respect to NCD evaluation and management.

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Importance: Basket-design clinical trials that allow investigation of treatment effects on different clinical syndromes that share the same molecular pathophysiology have not previously been attempted in neurodegenerative disease.

Objective: To assess the safety, tolerability, and pharmacodynamics of the microtubule stabilizer TPI-287 (abeotaxane) in Alzheimer disease (AD) or the 4-repeat tauopathies (4RT) progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS).

Design, Setting, And Participants: Two parallel-design, double-blind, placebo-controlled phase 1 randomized clinical trials in AD and 4RT were conducted from December 20, 2013, through May 4, 2017, at the University of California, San Francisco, and University of Alabama at Birmingham.

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Introduction: Differential patterns of brain atrophy on structural magnetic resonance imaging (MRI) revealed four reproducible subtypes of Alzheimer's disease (AD): (1) "typical", (2) "limbic-predominant", (3) "hippocampal-sparing", and (4) "mild atrophy". We examined the neurobiological characteristics and clinical progression of these atrophy-defined subtypes.

Methods: The four subtypes were replicated using a clustering method on MRI data in 260 amyloid-β-positive patients with mild cognitive impairment or AD dementia, and we subsequently tested whether the subtypes differed on [ F]flortaucipir (tau) positron emission tomography, white matter hyperintensity burden, and rate of global cognitive decline.

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Article Synopsis
  • The study aimed to analyze neuroimaging results in patients at risk for Chronic Traumatic Encephalopathy (CTE), focusing on individuals with Traumatic Encephalopathy Syndrome (TES) due to repetitive head injuries from impact sports, primarily American football.
  • Eleven male patients (average age 64) underwent various neuroimaging tests, revealing distinct patterns: two showed amyloid positivity linked to severe brain atrophy, while among those who were amyloid-negative, tau-PET indicated mild abnormalities, particularly in frontotemporal regions.
  • The findings suggest that tau-PET imaging could serve as a useful biomarker for identifying tau-related changes associated with CTE, although it may not be effective for
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Tau aggregation is a hallmark feature in a subset of patients with frontotemporal dementia (FTD). Early and selective loss of von Economo neurons (VENs) and fork cells within the frontoinsular (FI) and anterior cingulate cortices (ACC) is observed in patients with sporadic behavioral variant FTD (bvFTD) due to frontotemporal lobar degeneration (FTLD), including FTLD with tau inclusions (FTLD-tau). Recently, we further showed that these specialized neurons show preferential aggregation of TDP-43 in FTLD-TDP.

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Primary tauopathies are characterized neuropathologically by inclusions containing abnormal forms of the microtubule-associated protein tau (MAPT) and clinically by diverse neuropsychiatric, cognitive, and motor impairments. Autosomal dominant mutations in the MAPT gene cause heterogeneous forms of frontotemporal lobar degeneration with tauopathy (FTLD-Tau). Common and rare variants in the MAPT gene increase the risk for sporadic FTLD-Tau, including progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD).

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Neurodegenerative diseases appear to progress by spreading via brain connections. Here we evaluated this transneuronal degeneration hypothesis by attempting to predict future atrophy in a longitudinal cohort of patients with behavioral variant frontotemporal dementia (bvFTD) and semantic variant primary progressive aphasia (svPPA). We determined patient-specific "epicenters" at baseline, located each patient's epicenters in the healthy functional connectome, and derived two region-wise graph theoretical metrics to predict future atrophy: (1) shortest path length to the epicenter and (2) nodal hazard, the cumulative atrophy of a region's first-degree neighbors.

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Our aim was to investigate the patterns and trajectories of white matter (WM) diffusion abnormalities in microtubule-associated protein tau (MAPT) mutations carriers. We studied 22 MAPT mutation carriers (12 asymptomatic, 10 symptomatic) and 20 noncarriers from 8 families, who underwent diffusion tensor imaging (DTI) and a subset (10 asymptomatic, 6 symptomatic MAPT mutation carriers, and 10 noncarriers) were followed annually (median = 4 years). Cross-sectional and longitudinal changes in mean diffusivity (MD) and fractional anisotropy were analyzed.

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Importance: Few health systems have adopted effective dementia care management programs. The Care Ecosystem is a model for delivering care from centralized hubs across broad geographic areas to caregivers and persons with dementia (PWDs) independently of their health system affiliations.

Objective: To determine whether the Care Ecosystem is effective in improving outcomes important to PWDs, their caregivers, and payers beyond those achieved with usual care.

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Common neurodegenerative diseases feature progressive accumulation of disease-specific protein aggregates in selectively vulnerable brain regions. Increasing experimental evidence suggests that misfolded disease proteins exhibit prion-like properties, including the ability to seed corruptive templating and self-propagation along axons. Direct evidence for transneuronal spread in patients, however, remains limited.

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Objective: A rare variant in TREM2 (p.R47H, rs75932628) has been consistently reported to increase the risk for Alzheimer disease (AD), while mixed evidence has been reported for association of the variant with other neurodegenerative diseases. Here, we investigated the frequency of the R47H variant in a diverse and well-characterized multicenter neurodegenerative disease cohort.

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Article Synopsis
  • An amendment to the original paper has been released.
  • You can find the amendment through a link provided at the top of the paper.
  • This update may contain important changes or additional information related to the original content.
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Introduction: Sleep-wake disturbances are a common and early feature in Alzheimer's disease (AD). The impact of early tau pathology in wake-promoting neurons (WPNs) remains unclear.

Methods: We performed stereology in postmortem brains from AD individuals and healthy controls to identify quantitative differences in morphological metrics in WPNs.

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Purpose Recent studies confirm the utility of speech-language intervention in primary progressive aphasia (PPA); however, long-term outcomes, ideal dosage parameters, and relative benefits of intervention across clinical variants warrant additional investigation. The purpose of this study was to determine whether naming treatment affords significant, lasting, and generalized improvement for individuals with semantic and logopenic PPA and whether dosage manipulations significantly affect treatment outcomes. Method Eighteen individuals with PPA (9 semantic and 9 logopenic variant) underwent lexical retrieval treatment designed to leverage spared cognitive-linguistic domains and develop self-cueing strategies to promote naming.

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Communication accommodation describes how individuals adjust their communicative style to that of their conversational partner. We predicted that interpersonal prosodic correlation related to pitch and timing would be decreased in behavioral variant frontotemporal dementia (bvFTD). We predicted that the interpersonal correlation in a timing measure and a pitch measure would be increased in right temporal FTD (rtFTD) due to sparing of the neural substrate for speech timing and pitch modulation but loss of social semantics.

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The semantic variant of primary progressive aphasia (svPPA) is a clinical syndrome characterized by neurodegeneration and progressive loss of semantic knowledge. Unlike many other forms of frontotemporal lobar degeneration (FTLD), svPPA has a highly consistent underlying pathology composed of TDP-43 (a regulator of RNA and DNA transcription metabolism). Previous genetic studies of svPPA are limited by small sample sizes and a paucity of common risk variants.

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Microsatellite repeat expansion disease loci can exhibit pleiotropic clinical and biological effects depending on repeat length. Large expansions in C9orf72 (100s-1000s of units) are the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal degeneration (FTD). However, whether intermediate expansions also contribute to neurodegenerative disease is not well understood.

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Background: Care navigation is an approach to personalized care management and care coordination that can help overcome barriers to care. Care navigation has not been extensively studied in dementia, where health care workforce innovations are needed as a result of increasing disease prevalence and resulting costs to the health care system.

Objective: To identify facilitators and barriers to care navigation in dementia and to assess dementia caregiver satisfaction with care navigation.

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Importance: Current attempts to gauge the acute care needs of patients with dementia have not effectively addressed the role of caregivers, despite their extensive involvement in decisions about acute care management.

Objective: To determine whether caregiver depression is associated with increased use of the emergency department (ED) among patients with dementia.

Design, Setting, And Participants: This longitudinal cohort study used data from the Care Ecosystem study, a randomized clinical trial examining telephone-based supportive care for patients with dementia and their caregivers.

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