Clinical recognition of frontotemporal dementia with right anterior temporal predominance: A multicenter retrospective cohort study.

INTRODUCTION: Although frontotemporal dementia (FTD) with right anterior temporal lobe (RATL) predominance has been recognized, a uniform description of the syndrome is still missing. This multicenter study aims to establish a cohesive clinical phenotype. METHODS: Retrospective clinical data from 18 centers across 12 countries yielded 360 FTD patients with predominant RATL atrophy through initial neuroimaging assessments. RESULTS: Common symptoms included mental rigidity/preoccupations (78%), disinhibition/socially inappropriate behavior (74%), naming/word-finding difficulties (70%), memory deficits (67%), apathy (65%), loss of empathy (65%), and face-recognition deficits (60%). Real-life examples unveiled impairments regarding landmarks, smells, sounds, tastes, and bodily sensations (74%). Cognitive test scores indicated deficits in emotion, people, social interactions, and visual semantics however, lacked objective assessments for mental rigidity and preoccupations. DISCUSSION: This study cumulates the largest RATL cohort unveiling unique RATL symptoms subdued in prior diagnostic guidelines. Our novel approach, combining real-life examples with cognitive tests, offers clinicians a comprehensive toolkit for managing these patients. HIGHLIGHTS: This project is the first international collaboration and largest reported cohort. Further efforts are warranted for precise nomenclature reflecting neural mechanisms. Our results will serve as a clinical guideline for early and accurate diagnoses.

Examining Associations Between Smartphone Use and Clinical Severity in Frontotemporal Dementia: Proof-of-Concept Study.

BACKGROUND: Frontotemporal lobar degeneration (FTLD) is a leading cause of dementia in individuals aged <65 years. Several challenges to conducting in-person evaluations in FTLD illustrate an urgent need to develop remote, accessible, and low-burden assessment techniques. Studies of unobtrusive monitoring of at-home computer use in older adults with mild cognitive impairment show that declining function is reflected in reduced computer use; however, associations with smartphone use are unknown. OBJECTIVE: This study aims to characterize daily trajectories in smartphone battery use, a proxy for smartphone use, and examine relationships with clinical indicators of severity in FTLD. METHODS: Participants were 231 adults (mean age 52.5, SD 14.9 years; n=94, 40.7% men; n=223, 96.5% non-Hispanic White) enrolled in the Advancing Research and Treatment of Frontotemporal Lobar Degeneration (ARTFL study) and Longitudinal Evaluation of Familial Frontotemporal Dementia Subjects (LEFFTDS study) Longitudinal Frontotemporal Lobar Degeneration (ALLFTD) Mobile App study, including 49 (21.2%) with mild neurobehavioral changes and no functional impairment (ie, prodromal FTLD), 43 (18.6%) with neurobehavioral changes and functional impairment (ie, symptomatic FTLD), and 139 (60.2%) clinically normal adults, of whom 55 (39.6%) harbored heterozygous pathogenic or likely pathogenic variants in an autosomal dominant FTLD gene. Participants completed the Clinical Dementia Rating plus National Alzheimer's Coordinating Center Frontotemporal Lobar Degeneration Behavior and Language Domains (CDR+NACC FTLD) scale, a neuropsychological battery; the Neuropsychiatric Inventory; and brain magnetic resonance imaging. The ALLFTD Mobile App was installed on participants' smartphones for remote, passive, and continuous monitoring of smartphone use. Battery percentage was collected every 15 minutes over an average of 28 (SD 4.2; range 14-30) days. To determine whether temporal patterns of battery percentage varied as a function of disease severity, linear mixed effects models examined linear, quadratic, and cubic effects of the time of day and their interactions with each measure of disease severity on battery percentage. Models covaried for age, sex, smartphone type, and estimated smartphone age. RESULTS: The CDR+NACC FTLD global score interacted with time on battery percentage such that participants with prodromal or symptomatic FTLD demonstrated less change in battery percentage throughout the day (a proxy for less smartphone use) than clinically normal participants (P<.001 in both cases). Additional models showed that worse performance in all cognitive domains assessed (ie, executive functioning, memory, language, and visuospatial skills), more neuropsychiatric symptoms, and smaller brain volumes also associated with less battery use throughout the day (P<.001 in all cases). CONCLUSIONS: These findings support a proof of concept that passively collected data about smartphone use behaviors associate with clinical impairment in FTLD. This work underscores the need for future studies to develop and validate passive digital markers sensitive to longitudinal clinical decline across neurodegenerative diseases, with potential to enhance real-world monitoring of neurobehavioral change.

Symptomatic progression of frontotemporal dementia with the TARDBP I383V variant.

We present a longitudinal description of a man with the TARDBP I383V variant of frontotemporal dementia (FTD). His progressive changes in behavior and language resulted in a diagnosis of the right temporal variant of FTD, also called the semantic behavioral variant (sbvFTD). We also present data from a small series of patients with the TARDBP I383V variant who were enrolled in a nationwide FTD research collaboration (ALLFTD). These data support slowly progressive loss of semantic function. While semantic dementia is infrequently considered genetic, the TARDBP I383V variant seems to be an exception. Longitudinal analyses in larger samples are warranted.

Evaluation of 90-day repeated dose oral toxicity of an aloe vera inner leaf gel beverage.

Despite its popularity along with many proposed therapeutic applications, the safety profile of Aloe vera gel beverages remains unsettled. The putative toxicology concern has focused on the hydroxyanthraquinone derivatives (HADs) found in the latex portion of the Aloe leaf. Despite harvesting and processing designed to eliminate or significantly reduce these compounds, certain HADs, such as aloin, may be present and have been associated with carcinogenicity in non-decolorized whole leaf extract containing approximately 6400 ppm aloin A and 71 ppm aloin-emodin. Sprague Dawley rats had free access to drinking water or a commercially and widely available Aloe vera gel beverage (Forever Living Products) prepared from the inner leaves of Aloe barbadensis Miller containing 3.43 ppm total aloin for 90 days. Under the conditions of the study and based on the toxicological endpoints evaluated, there were no adverse test substance-related findings, including altered thyroid hormones. No histologic differences or histopathological changes were detected in the multiple tissues and organs examined. The Ki-67 proliferation assay demonstrated no increased cell proliferation in the liver, lungs, kidneys, or urinary bladder, which might have been attributed to the dietary administration of the Aloe vera gel beverage via drinking water for 90 days. These data lend increasing confidence regarding the safety of appropriately processed Aloe vera gel beverages, such as the beverage tested in this study.

Enhancing the human health and lifespan: a targeted strategy emphasizing statins.

There has been substantial research interest in finding activities/agents that slow the onset and reduce the severity of numerous age-related diseases/conditions. This assessment indicates that the most studied agent intended to promote health in human population investigations for a broad spectrum of diseases are the statins, with large-scale epidemiological studies addressing numerous health endpoints. The key findings are that statin treatment consistently reduces the occurrence and attenuates the course of numerous non-communicable and contagious pathologies and numerous types of cancer with high mortality rates by about 20-50%. That one agent could affect such a broad based and consistently positive trends in epidemiological studies is unexpected and impressive, along with consistent cell and animal model research. Underlying mechanisms have been proposed that significantly contribute to the spectrum of salutary effects of statins, especially the capacity to activate Nrf2 showing hormetic dose responses in multiple organs and cell types, due to its bioavailability and broad tissue distribution. The widespread use of statins, which has the capacity to enhance human health span, should be considered for experimental exploration as a novel public health strategy that includes practical approaches for reduction of the most common adverse effects of this class of drugs including myalgia/myopathy and transaminitis.

Reliability and Validity of Smartphone Cognitive Testing for Frontotemporal Lobar Degeneration.

Importance: Frontotemporal lobar degeneration (FTLD) is relatively rare, behavioral and motor symptoms increase travel burden, and standard neuropsychological tests are not sensitive to early-stage disease. Remote smartphone-based cognitive assessments could mitigate these barriers to trial recruitment and success, but no such tools are validated for FTLD. Objective: To evaluate the reliability and validity of smartphone-based cognitive measures for remote FTLD evaluations. Design, Setting, and Participants: In this cohort study conducted from January 10, 2019, to July 31, 2023, controls and participants with FTLD performed smartphone application (app)-based executive functioning tasks and an associative memory task 3 times over 2 weeks. Observational research participants were enrolled through 18 centers of a North American FTLD research consortium (ALLFTD) and were asked to complete the tests remotely using their own smartphones. Of 1163 eligible individuals (enrolled in parent studies), 360 were enrolled in the present study; 364 refused and 439 were excluded. Participants were divided into discovery (n = 258) and validation (n = 102) cohorts. Among 329 participants with data available on disease stage, 195 were asymptomatic or had preclinical FTLD (59.3%), 66 had prodromal FTLD (20.1%), and 68 had symptomatic FTLD (20.7%) with a range of clinical syndromes. Exposure: Participants completed standard in-clinic measures and remotely administered ALLFTD mobile app (app) smartphone tests. Main Outcomes and Measures: Internal consistency, test-retest reliability, association of smartphone tests with criterion standard clinical measures, and diagnostic accuracy. Results: In the 360 participants (mean [SD] age, 54.0 [15.4] years; 209 [58.1%] women), smartphone tests showed moderate-to-excellent reliability (intraclass correlation coefficients, 0.77-0.95). Validity was supported by association of smartphones tests with disease severity (r range, 0.38-0.59), criterion-standard neuropsychological tests (r range, 0.40-0.66), and brain volume (standardized ß range, 0.34-0.50). Smartphone tests accurately differentiated individuals with dementia from controls (area under the curve [AUC], 0.93 [95% CI, 0.90-0.96]) and were more sensitive to early symptoms (AUC, 0.82 [95% CI, 0.76-0.88]) than the Montreal Cognitive Assessment (AUC, 0.68 [95% CI, 0.59-0.78]) (z of comparison, -2.49 [95% CI, -0.19 to -0.02]; P = .01). Reliability and validity findings were highly similar in the discovery and validation cohorts. Preclinical participants who carried pathogenic variants performed significantly worse than noncarrier family controls on 3 app tasks (eg, 2-back ß = -0.49 [95% CI, -0.72 to -0.25]; P < .001) but not a composite of traditional neuropsychological measures (ß = -0.14 [95% CI, -0.42 to 0.14]; P = .32). Conclusions and Relevance: The findings of this cohort study suggest that smartphones could offer a feasible, reliable, valid, and scalable solution for remote evaluations of FTLD and may improve early detection. Smartphone assessments should be considered as a complementary approach to traditional in-person trial designs. Future research should validate these results in diverse populations and evaluate the utility of these tests for longitudinal monitoring.

Gene specific effects on brain volume and cognition of TMEM106B in frontotemporal lobar degeneration.

Background and Objectives: TMEM106B has been proposed as a modifier of disease risk in FTLD-TDP, particularly in GRN mutation carriers. Furthermore, TMEM106B has been investigated as a disease modifier in the context of healthy aging and across multiple neurodegenerative diseases. The objective of this study is to evaluate and compare the effect of TMEM106B on gray matter volume and cognition in each of the common genetic FTD groups and in sporadic FTD patients. Methods: Participants were enrolled through the ARTFL/LEFFTDS Longitudinal Frontotemporal Lobar Degeneration (ALLFTD) study, which includes symptomatic and presymptomatic individuals with a pathogenic mutation in C9orf72, GRN, MAPT, VCP, TBK1, TARDBP, symptomatic non-mutation carriers, and non-carrier family controls. All participants were genotyped for the TMEM106B rs1990622 SNP. Cross-sectionally, linear mixed-effects models were fitted to assess an association between TMEM106B and genetic group interaction with each outcome measure (gray matter volume and UDS3-EF for cognition), adjusting for education, age, sex and CDR®+NACC-FTLD sum of boxes. Subsequently, associations between TMEM106B and each outcome measure were investigated within the genetic group. For longitudinal modeling, linear mixed-effects models with time by TMEM106B predictor interactions were fitted. Results: The minor allele of TMEM106B rs1990622, linked to a decreased risk of FTD, associated with greater gray matter volume in GRN mutation carriers under the recessive dosage model. This was most pronounced in the thalamus in the left hemisphere, with a retained association when considering presymptomatic GRN mutation carriers only. The minor allele of TMEM106B rs1990622 also associated with greater cognitive scores among all C9orf72 mutation carriers and in presymptomatic C9orf72 mutation carriers, under the recessive dosage model. Discussion: We identified associations of TMEM106B with gray matter volume and cognition in the presence of GRN and C9orf72 mutations. This further supports TMEM106B as modifier of TDP-43 pathology. The association of TMEM106B with outcomes of interest in presymptomatic GRN and C9orf72 mutation carriers could additionally reflect TMEM106B's impact on divergent pathophysiological changes before the appearance of clinical symptoms.

Δ9-Tetrahydrocannabinol (THC): A Critical Overview of Recent Clinical Trials and Suggested Guidelines for Future Research.

In this overview, we seek to appraise recent experimental and observational studies investigating THC and its potential role as adjunctive therapy in various medical illnesses. Recent clinical trials are suggestive of the diverse pharmacologic potentials for THC but suffer from small sample sizes, short study duration, failure to address tolerance, little dose variation, ill-defined outcome measures, and failure to identify and/or evaluate confounds, all of which may constitute significant threats to the validity of most trials. However, the existing work underscores the potential therapeutic value of THC and, at the same time, calls attention to the critical need for better-designed protocols to fully explore and demonstrate safety and efficacy. In the most general sense, the present brief review illuminates some intriguing findings about THC, along with the basic threats to the validity of the research that supports those findings. The intent is to highlight existing generic weaknesses in the existing randomized controlled trial literature and, most importantly, provide guidance for improved clinical research.

RUTIN, a widely consumed flavonoid, that commonly induces hormetic effects.

Rutin is a flavonoid present in numerous fruits and vegetables and therefore widely consumed by humans. It is also a popular dietary supplement of 250-500 mg/day. There is considerable consumer interest in rutin due to numerous reports in the biomedical literature of its multi-system chemo-preventive properties. The present paper provides the first assessment of rutin-induced hormetic concentration/dose responses, their quantitative features and mechanistic basis, along with their biological, biomedical, clinical, and public health implications. The findings indicate that rutin-induced hormetic dose responses are widespread, being reported in numerous biological models and cell types for a wide range of endpoints. Of critical importance is that the optimal hormetic findings shown in in vitro systems are currently not achievable for human populations due to low gastrointestinal tract bioavailability. These findings have the potential to strengthen future experimental studies with rutin, particularly concerning study design parameters.

Taurine induces hormesis in multiple biological models: May have transformative implications for overall societal health.

This paper represents the first integrative assessment and documentation of taurine-induced hormetic effects in the biological and biomedical areas, their dose response features, mechanistic frameworks, and possible public health, therapeutic and commercial applications. Taurine-induced hormetic effects are documented in a wide range of experimental models, cell types and for numerous biological endpoints, with most of these experimental findings being reported within the past five years. It is suggested that the concept of hormesis may have a transformative effect on taurine research and its public health and therapeutic applications.

Flavonoids commonly induce hormetic responses.

The present paper provides a new perspective of previously published findings by Siwak (Food Chem 141:1227-1241, 2013) which showed that 15 structurally diverse flavonoids reduced toxicity (i.e., enhanced cell viability) from hypochlorite using the MTT assay within a pre-conditioning experimental protocol, with each agent showing a similar biphasic concentration response relationship. We use this Commentary to point out that each of the concentration response relationships are consistent with the hormetic dose response. The paper of Siwak (Food Chem 141:1227-1241, 2013) is unique in that it provides a comparison of a relatively large number of agents using the identical experimental protocol.

Hormesis determines lifespan.

This paper addresses how long lifespan can be extended via multiple interventions, such as dietary supplements [e.g., curcumin, resveratrol, sulforaphane, complex phytochemical mixtures (e.g., Moringa, Rhodiola)], pharmaceutical agents (e.g., metformin), caloric restriction, intermittent fasting, exercise and other activities. This evaluation was framed within the context of hormesis, a biphasic dose response with specific quantitative features describing the limits of biological/phenotypic plasticity for integrative biological endpoints (e.g., cell proliferation, memory, fecundity, growth, tissue repair, stem cell population expansion/differentiation, longevity). Evaluation of several hundred lifespan extending agents using yeast, nematode (Caenorhabditis elegans), multiple insect and other invertebrate and vertebrate models (e.g., fish, rodents), revealed they responded in a manner [average (mean/median) and maximum lifespans] consistent with the quantitative features [i.e., 30-60% greater at maximum (Hormesis Rule)] of the hormetic dose response. These lifespan extension features were independent of biological model, inducing agent, endpoints measured and mechanism. These findings indicate that hormesis describes the capacity to extend life via numerous agents and activities and that the magnitude of lifespan extension is modest, in the percentage, not fold, range. These findings have important implications for human aging, genetic diseases/environmental stresses and lifespan extension, as well as public health practices and long-term societal resource planning.

Lobar Microbleeds in the Posterior Cortical Atrophy Syndrome: A Comparison to Typical Alzheimer's Disease.

PURPOSE OF THE STUDY: Posterior cortical atrophy is a clinico-radiographical syndrome that presents with higher-order visual dysfunction and is most commonly due to Alzheimer's disease. Understanding factors associated with atypical presentations of Alzheimer's disease, such as posterior cortical atrophy (PCA), holds promise to shape our understanding of AD pathophysiology. Thus, we aimed to compare MRI evidence of lobar microbleeds (LMBs) in posterior cortical atrophy (PCA) syndrome to typical AD (tAD) and to assess and compare MRI evidence of cerebral amyloid angiopathy (CAA) in each group. FINDINGS: We retrospectively collected clinical and MRI data from participants with PCA (n = 26), identified from an institutional PCA registry, and participants with tAD (n = 46) identified from electronic health records from a single institution. LMBs were identified on susceptibility-weighted imaging (SWI); the Fazekas grade of white matter disease was assessed using FLAIR images, and Boston criteria version 2.0 for cerebral amyloid angiopathy were applied to all data. The proportion of participants with PCA and LMB (7.7%) was lower than for tAD (47.8%) (p = 0.005). The frequency of "probable" CAA was similar in both groups, while "possible" CAA was more frequent in tAD (30.4%) than PCA (0%) (p = 0.001). The Fazekas grades were not different between groups. Lobar microbleeds on SWI were not more common in PCA than in typical AD. Clinicopathological investigations are necessary to confirm these findings. The factors that contribute to the posterior cortical atrophy phenotype are unknown.

Psychiatric Screening Measures in Behavioral Variant Frontotemporal Dementia.

OBJECTIVE: Behavioral variant frontotemporal dementia (bvFTD) is sometimes misdiagnosed as a primary psychiatric disorder, such as major depressive disorder, bipolar disorder, an anxiety disorder, autism spectrum disorder (ASD), or attention-deficit hyperactivity disorder (ADHD). Nonspecialists often use screening measures for primary psychiatric disorders in early assessments of persons with bvFTD. The investigators aimed to evaluate the manifestations of bvFTD in surveys intended to screen for primary psychiatric disorders. METHODS: Patients with bvFTD (N=27) presenting to an academic neurobehavior specialty clinic and their caregivers were provided questionnaire packets including the Mood Disorder Questionnaire (MDQ), the Patient Health Questionnaire-9 (PHQ-9), the Generalized Anxiety Disorder-7 scale (GAD-7), the Adult ADHD Self-Report Scale, version 1.1, the Ritvo Autism and Asperger Diagnostic Scale, and the Neuropsychiatric Inventory Questionnaire. Established cutoff scores suggesting the presence of a primary psychiatric disorder were used to define a "positive" response. Individual questions from each screening questionnaire were examined for a more granular characterization of bvFTD. RESULTS: Overall, 15% of bvFTD patients screened positive for bipolar disorder, 54% screened positive for ADHD, and 89% screened positive for ASD. Hyperactivity or hypersensitivity symptoms were infrequently endorsed. In addition, 57% of respondents screened positive for depressive symptoms on the PHQ-9, and 43% screened positive for anxiety symptoms on the GAD-7. CONCLUSIONS: The use of cutoff scores on screening measures for primary psychiatric disorders resulted in potentially problematic positive screens of primary psychiatric disorders among persons with bvFTD. Identifying specific questions that distinguish between bvFTD and primary psychiatric disorders requires further study.

Quercetin induces its chemoprotective effects via hormesis.

Quercetin is a polyphenol present in numerous fruits and vegetables and therefore widely consumed by humans with average daily dietary intakes of 10-20 mg/day. It is also a popular dietary supplement of 250-1000 mg/day. However, despite the widespread consumer interest in quercetin, due to its possible chemopreventive properties, the extensively studied quercetin presents a highly diverse and complex array of biological effects. Consequently, the present paper provides the first assessment of quercetin-induced hormetic concentration/dose responses, their quantitative features and mechanistic foundations, and their biological, biomedical, clinical, and public health implications. The findings indicate that quercetin-induced hormetic dose responses are widespread, being independent of biological model, cell type, and endpoint. These findings have the potential to enlighten future experimental studies with quercetin especially with respect to study design parameters and may also affect the appraisal of possible public health benefits and risks associated with highly diverse consumer consumption practices.

Polyamines and hormesis: Making sense of a dose response dichotomy.

The diverse biological effects of polyamines (putrescine, spermidine and spermine) were reviewed in the context of hormesis in an integrative manner for the first time. The findings illustrate that each of these polyamines commonly induces hormetic dose responses in a wide range of biological models and types of cells for multiple endpoints in numerous plant species and animal models. Plant research emphasized preconditioning experimental studies in which the respective polyamines conferred some protection against the damaging effects of a broad range of environmental stressors such as drought, salinity, cold/heat, heavy metals and UV-damage in an hormetic manner. Polyamine-based animal hormesis studies emphasized biomedical endpoints such as longevity and neuroprotection. These findings have important biological and biomedical implications and should guide experimental designs of low dose investigations.

Hormesis, biological plasticity, and implications for clinical trial research.

The present paper identifies a critical factor that leads to false negative results (i.e., failing to indicate efficacy when beneficial results did occur) in randomized human drug trials. The paper demonstrates that human performance can only be enhanced by a maximum of 30-60% as described by the hormetic dose response which defines the limits of biological plasticity. However, human epidemiological/clinical trials typically contain such extensive variability that often requires responses greater than 2-3 times control group responses to show statistical significance. Thus, many potentially beneficial agents may be missed because the clinical trial fails to recognize and take into consideration the limits of biological plasticity. The paper proposes that this hormesis-biological plasticity-clinical trial conundrum can be addressed successfully via the use of a weight-of-evidence methodology similar to that used by regulatory agencies such as EPA in environmental assessment of chemical toxicity.

Astrogliosis, neuritic microstructure, and sex effects: GFAP is an indicator of neuritic orientation in women.

BACKGROUND: Data from human studies suggest that immune dysregulation is associated with Alzheimer's disease (AD) pathology and cognitive decline and that neurites may be affected early in the disease trajectory. Data from animal studies further indicate that dysfunction in astrocytes and inflammation may have a pivotal role in facilitating dendritic damage, which has been linked with negative cognitive outcomes. To elucidate these relationships further, we have examined the relationship between astrocyte and immune dysregulation, AD-related pathology, and neuritic microstructure in AD-vulnerable regions in late life. METHODS: We evaluated panels of immune, vascular, and AD-related protein markers in blood and conducted in vivo multi-shell neuroimaging using Neurite Orientation Dispersion and Density Imaging (NODDI) to assess indices of neuritic density (NDI) and dispersion (ODI) in brain regions vulnerable to AD in a cohort of older adults (n = 109). RESULTS: When examining all markers in tandem, higher plasma GFAP levels were strongly related to lower neurite dispersion (ODI) in grey matter. No biomarker associations were found with higher neuritic density. Associations between GFAP and neuritic microstructure were not significantly impacted by symptom status, APOE status, or plasma Aß42/40 ratio; however, there was a large sex effect observed for neurite dispersion, wherein negative associations between GFAP and ODI were only observed in females. DISCUSSION: This study provides a comprehensive, concurrent appraisal of immune, vascular, and AD-related biomarkers in the context of advanced grey matter neurite orientation and dispersion methodology. Sex may be an important modifier of the complex associations between astrogliosis, immune dysregulation, and brain microstructure in older adults.

Expressive Prosody in Patients With Focal Anterior Temporal Neurodegeneration.

BACKGROUND AND OBJECTIVES: Progressive focal anterior temporal lobe (ATL) neurodegeneration has been historically called semantic dementia. More recently, semantic variant primary progressive aphasia (svPPA) and semantic behavioral variant frontotemporal dementia (sbvFTD) have been linked with predominant left and right ATL neurodegeneration, respectively. Nonetheless, clinical tools for an accurate diagnosis of sbvFTD are still lacking. Expressive prosody refers to the modulation of pitch, loudness, tempo, and quality of voice used to convey emotional and linguistic information and has been linked to bilateral but right-predominant frontotemporal functioning. Changes in expressive prosody can be detected with semiautomated methods and could represent a useful diagnostic marker of socioemotional functioning in sbvFTD. METHODS: Participants underwent a comprehensive neuropsychological and language evaluation and a 3T MRI at the University of California San Francisco. Each participant provided a verbal description of the picnic scene from the Western Aphasia Battery. The fundamental frequency (f0) range, an acoustic measure of pitch variability, was extracted for each participant. We compared the f0 range between groups and investigated associations with an informant-rated measure of empathy, a facial emotion labeling task, and gray matter (GM) volumes using voxel-based morphometry. RESULTS: Twenty-eight patients with svPPA, 18 with sbvFTD, and 18 healthy controls (HCs) were included. f0 range was significantly different across groups: patients with sbvFTD showed reduced f0 range in comparison with both patients with svPPA (mean difference of -1.4 ± 2.4 semitones; 95% CI -2.4 to -0.4]; p < 0.005) and HCs (mean difference of -1.9 ± 3.0 semitones; 95% CI -3.0 to -0.7]; p < 0.001). A higher f0 range was correlated with a greater informant-rated empathy (r = 0.355; p ≤ 0.05), but not facial emotion labeling. Finally, the lower f0 range was correlated with lower GM volume in the right superior temporal gyrus, encompassing anterior and posterior portions (p < 0.05 FWE cluster corrected). DISCUSSION: Expressive prosody may be a useful clinical marker of sbvFTD. Reduced empathy is a core symptom in sbvFTD; the present results extend this to prosody, a core component of social interaction, at the intersection of speech and emotion. They also inform the long-standing debate on the lateralization of expressive prosody in the brain, highlighting the critical role of the right superior temporal lobe.