Examining the language and behavioural profile in FTD and ALS-FTD

'Communication is difficult': Speech, language and communication needs of people with young onset or rarer forms of non-language led dementia

BACKGROUND

People with behavioural variant frontotemporal dementia, Lewy body dementia, posterior cortical atrophy and young onset Alzheimer's disease may experience language and communication difficulties. However, the role of speech and language interventions for people with these non-language led dementias has received little attention.

AIMS

This study aimed to explore the experiences and perspectives of people living with these conditions, and their families, regarding their language and communication difficulties and how speech and language therapy could address these needs.

METHODS

This study employed a qualitative design to explore the experiences of people living with or caring for somebody with behavioural variant frontotemporal dementia, Lewy body dementia, posterior cortical atrophy or young onset Alzheimer's disease, and to understand their opinions about speech and language therapy. Participants were recruited from a support service connected to a dementia clinic to attend one of five focus group meetings. Videorecorded focus groups and interviews were transcribed, and reflexive thematic analysis was used to analyse data from people affected by each type of dementia.

RESULTS

A total of 25 participants were recruited to the study, with representation across the different forms of non-language led dementias. The four main themes identified were: (1) communication difficulties as a key difficulty, (2) loss and loneliness, (3) speech and language therapy, and (4) the role of the caregiver. Sixteen subthemes were also identified which highlighted individual issues across disease types.

DISCUSSION

Although all the forms of dementia studied here are not considered to be language-led, people with these conditions and/or their care partners identified speech, language and communication as common challenges. These communication difficulties were reported to have a negative impact on their social participation and mental health and participants felt speech and language interventions could help. There is a need for research exploring speech and language interventions developed for and with people with non-language led dementias and their care partners, to ensure they meet the needs of the people they are designed for.

WHAT THIS PAPER ADDS

What is already known on the subject People with primary progressive aphasia present with speech, language and communication difficulties, and several speech and language interventions have been developed to meet the needs of this population. However, people with non-language led dementias may also experience speech, language and communication difficulties, and little is known about interventions that may address these difficulties. What this paper adds to existing knowledge People living with or caring for somebody with behavioural variant frontotemporal dementia, Lewy body dementia, posterior cortical atrophy and young onset Alzheimer's disease report experiencing speech, language and communication difficulties that impact on the person with dementia's social participation and mood. Participants in this study also shared their opinions about how speech and language interventions could help, from the earliest stages of the disease. What are the potential or actual clinical implications of this work? Speech and language therapists need to address the individual speech, language and communication needs of people with dementias, even those that are not thought to be language-led. Current speech and language therapy service provision does not meet the needs of people with non-language led dementias and further research is required to develop interventions and services to meet these needs.

Updates on Disease Mechanisms and Therapeutics for Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS), or Lou Gehrig's disease, is a motor neuron disease. In ALS, upper and lower motor neurons in the brain and spinal cord progressively degenerate during the course of the disease, leading to the loss of the voluntary movement of the arms and legs. Since its first description in 1869 by a French neurologist Jean-Martin Charcot, the scientific discoveries on ALS have increased our understanding of ALS genetics, pathology and mechanisms and provided novel therapeutic strategies. The goal of this review article is to provide a comprehensive summary of the recent findings on ALS mechanisms and related therapeutic strategies to the scientific audience. Several highlighted ALS research topics discussed in this article include the 2023 FDA approved drug for SOD1 ALS, the updated C9orf72 GGGGCC repeat-expansion-related mechanisms and therapeutic targets, TDP-43-mediated cryptic splicing and disease markers and diagnostic and therapeutic options offered by these recent discoveries.

A comprehensive review on frontotemporal dementia: its impact on language, speech and behavior

Frontotemporal dementia (FTD) is a progressive neurodegenerative disorder defined by the selective deterioration of the frontal and temporal lobes of the brain. This comprehensive review explored the effect of FTD on language, speech, and behavior. Early symptoms include difficulty in word finding, reduced speech output, and comprehension deficits, often leading to aphasia. The study discussed the profound behavioral changes observed in FTD patients, including apathy, disinhibition, compulsive behaviors, and loss of empathy, the importance of an accurate and early diagnosis, and its challenges. We even reviewed the potential for targeted therapies and the essential role of multidisciplinary care in managing the language, speech, and behavioral aspects of FTD. By examining objective data and comprehensive research on the subject, this study offers valuable insights into FTD's profound effects on language, speech, and behavior, assisting in improved clinical management and potential therapeutic strategies for this devastating condition.

Neurocognitive correlates of semantic memory navigation in Parkinson's disease

Cognitive studies on Parkinson's disease (PD) reveal abnormal semantic processing. Most research, however, fails to indicate which conceptual properties are most affected and capture patients' neurocognitive profiles. Here, we asked persons with PD, healthy controls, and individuals with behavioral variant frontotemporal dementia (bvFTD, as a disease control group) to read concepts (e.g., 'sun') and list their features (e.g., hot). Responses were analyzed in terms of ten word properties (including concreteness, imageability, and semantic variability), used for group-level comparisons, subject-level classification, and brain-behavior correlations. PD (but not bvFTD) patients produced more concrete and imageable words than controls, both patterns being associated with overall cognitive status. PD and bvFTD patients showed reduced semantic variability, an anomaly which predicted semantic inhibition outcomes. Word-property patterns robustly classified PD (but not bvFTD) patients and correlated with disease-specific hypoconnectivity along the sensorimotor and salience networks. Fine-grained semantic assessments, then, can reveal distinct neurocognitive signatures of PD.

Social disinhibition in acquired brain injury and neurological disease: a concept analysis

BACKGROUND

Social disinhibition is becoming increasingly recognised in the neuropsychological literature as a complex and debilitating sequalae associated with acquired frontal lobe damage. Despite this, the term has been inconsistently defined and described in both clinical and research contexts. The purpose of this paper was to explore and examine the concept of social disinhibition in the context of brain injury and other organic neurological conditions.

METHOD

A literature search for articles published in the English language from journal inception to June 2021 was conducted using MEDLINE, PsycInfo, Embase, CINAHL and Web of Science. A 'concept analysis' was conducted on the identified literature using Walker & Avant's (2019) framework.

RESULTS

The analysis suggested that while several terms are often used interchangeably with social disinhibition, including impulsivity and behavioural dysregulation, these terms may be differentiated and defined separately within the broader domain of 'behaviours of concern'. Attributes, antecedents and consequences of social disinhibition were also identified and discussed.

CONCLUSIONS

Clarifying the concept of social disinhibition has important implications in both clinical and research contexts, including increased understanding of the behaviours, more accurate estimates of incidence and prevalence, and the development and implementation of targeted rehabilitation programmes.

Somatic Mosaicism in Amyotrophic Lateral Sclerosis and Frontotemporal Dementia Reveals Widespread Degeneration from Focal Mutations

Although mutations in dozens of genes have been implicated in familial forms of amyotrophic lateral sclerosis (fALS) and frontotemporal degeneration (fFTD), most cases of these conditions are sporadic (sALS and sFTD), with no family history, and their etiology remains obscure. We tested the hypothesis that somatic mosaic mutations, present in some but not all cells, might contribute in these cases, by performing ultra-deep, targeted sequencing of 88 genes associated with neurodegenerative diseases in postmortem brain and spinal cord samples from 404 individuals with sALS or sFTD and 144 controls. Known pathogenic germline mutations were found in 20.6% of ALS, and 26.5% of FTD cases. Predicted pathogenic somatic mutations in ALS/FTD genes were observed in 2.7% of sALS and sFTD cases that did not carry known pathogenic or novel germline mutations. Somatic mutations showed low variant allele fraction (typically <2%) and were often restricted to the region of initial discovery, preventing detection through genetic screening in peripheral tissues. Damaging somatic mutations were preferentially enriched in primary motor cortex of sALS and prefrontal cortex of sFTD, mirroring regions most severely affected in each disease. Somatic mutation analysis of bulk RNA-seq data from brain and spinal cord from an additional 143 sALS cases and 23 controls confirmed an overall enrichment of somatic mutations in sALS. Two adult sALS cases were identified bearing pathogenic somatic mutations in DYNC1H1 and LMNA, two genes associated with pediatric motor neuron degeneration. Our study suggests that somatic mutations in fALS/fFTD genes, and in genes associated with more severe diseases in the germline state, contribute to sALS and sFTD, and that mosaic mutations in a small fraction of cells in focal regions of the nervous system can ultimately result in widespread degeneration.

Speech and language markers of neurodegeneration: a call for global equity

In the field of neurodegeneration, speech and language assessments are useful for diagnosing aphasic syndromes and for characterizing other disorders. As a complement to classic tests, scalable and low-cost digital tools can capture relevant anomalies automatically, potentially supporting the quest for globally equitable markers of brain health. However, this promise remains unfulfilled due to limited linguistic diversity in scientific works and clinical instruments. Here we argue for cross-linguistic research as a core strategy to counter this problem. First, we survey the contributions of linguistic assessments in the study of primary progressive aphasia and the three most prevalent neurodegenerative disorders worldwide-Alzheimer's disease, Parkinson's disease, and behavioural variant frontotemporal dementia. Second, we address two forms of linguistic unfairness in the literature: the neglect of most of the world's 7000 languages and the preponderance of English-speaking cohorts. Third, we review studies showing that linguistic dysfunctions in a given disorder may vary depending on the patient's language and that English speakers offer a suboptimal benchmark for other language groups. Finally, we highlight different approaches, tools and initiatives for cross-linguistic research, identifying core challenges for their deployment. Overall, we seek to inspire timely actions to counter a looming source of inequity in behavioural neurology.

Development of a Speech-based Composite Score for Remotely Quantifying Language Changes in Frontotemporal Dementia

BACKGROUND

Changes to speech and language are common symptoms across different subtypes of frontotemporal dementia (FTD). These changes affect the ability to communicate, impacting everyday functions. Accurately assessing these changes may help clinicians to track disease progression and detect response to treatment.

OBJECTIVE

To determine which aspects of speech show significant change over time and to develop a novel composite score for tracking speech and language decline in individuals with FTD.

METHOD

We recruited individuals with FTD to complete remote digital speech assessments based on a picture description task. Speech samples were analyzed to derive acoustic and linguistic measures of speech and language, which were tested for longitudinal change over the course of the study and were used to compute a novel composite score.

RESULTS

Thirty-six (16 F, 20 M; M age = 61.3 years) individuals were enrolled in the study, with 27 completing a follow-up assessment 12 months later. We identified eight variables reflecting different aspects of language that showed longitudinal decline in the FTD clinical syndrome subtypes and developed a novel composite score based on these variables. The resulting composite score demonstrated a significant effect of change over time, high test-retest reliability, and a correlation with standard scores on various other speech tasks.

CONCLUSION

Remote digital speech assessments have the potential to characterize speech and language abilities in individuals with FTD, reducing the burden of clinical assessments while providing a novel measure of speech and language abilities that is sensitive to disease and relevant to everyday function.

Neuropsychological impairment in amyotrophic lateral sclerosis-frontotemporal spectrum disorder

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with a rapid course, characterized by motor neuron dysfunction, leading to progressive disability and death. This Review, which is aimed at neurologists, psychologists and other health professionals who follow evidence-based practice relating to ALS and frontotemporal dementia (FTD), examines the neuropsychological evidence that has driven the reconceptualization of ALS as a spectrum disorder ranging from a pure motor phenotype to ALS-FTD. It focuses on changes in cognition and behaviour, which vary in severity across the spectrum: around 50% individuals with ALS are within the normal range, 15% meet the criteria for ALS-FTD, and the remaining 35% are in the mid-spectrum range with milder and more focal impairments. The cognitive impairments include deficits in verbal fluency, executive functions, social cognition and language, and apathy is the most prevalent behavioural change. The pattern and severity of cognitive and behavioural change predicts underlying regional cerebral dysfunction from brain imaging and post-mortem pathology. Our increased recognition of cognition and behaviour as part of the ALS phenotype has led to the development and standardization of assessment tools, which have been incorporated into research and clinical care. Measuring change over the course of the disease is vital for clinical trials, and neuropsychology is proving to be a biomarker for the earliest preclinical changes.

Recent Advances in Extracellular Vesicles in Amyotrophic Lateral Sclerosis and Emergent Perspectives

Amyotrophic lateral sclerosis (ALS) is a severe and incurable neurodegenerative disease characterized by the progressive death of motor neurons, leading to paralysis and death. It is a rare disease characterized by high patient-to-patient heterogeneity, which makes its study arduous and complex. Extracellular vesicles (EVs) have emerged as important players in the development of ALS. Thus, ALS phenotype-expressing cells can spread their abnormal bioactive cargo through the secretion of EVs, even in distant tissues. Importantly, owing to their nature and composition, EVs' formation and cargo can be exploited for better comprehension of this elusive disease and identification of novel biomarkers, as well as for potential therapeutic applications, such as those based on stem cell-derived exosomes. This review highlights recent advances in the identification of the role of EVs in ALS etiopathology and how EVs can be promising new therapeutic strategies.

Language impairment in the genetic forms of behavioural variant frontotemporal dementia

BACKGROUND

Behavioural variant fronto-temporal dementia (bvFTD) is characterised by a progressive change in personality in association with atrophy of the frontal and temporal lobes. Whilst language impairment has been described in people with bvFTD, little is currently known about the extent or type of linguistic difficulties that occur, particularly in the genetic forms.

METHODS

Participants with genetic bvFTD along with healthy controls were recruited from the international multicentre Genetic FTD Initiative (GENFI). Linguistic symptoms were assessed using items from the Progressive Aphasia Severity Scale (PASS). Additionally, participants undertook the Boston Naming Test (BNT), modified Camel and Cactus Test (mCCT) and a category fluency test. Participants underwent a 3T volumetric T1-weighted MRI, with language network regional brain volumes measured and compared between the genetic groups and controls.

RESULTS

76% of the genetic bvFTD cohort had impairment in at least one language symptom: 83% C9orf72, 80% MAPT and 56% GRN mutation carriers. All three genetic groups had significantly impaired functional communication, decreased fluency, and impaired sentence comprehension. C9orf72 mutation carriers also had significantly impaired articulation and word retrieval as well as dysgraphia whilst the MAPT mutation group also had impaired word retrieval and single word comprehension. All three groups had difficulties with naming, semantic knowledge and verbal fluency. Atrophy in key left perisylvian language regions differed between the groups, with generalised involvement in the C9orf72 group and more focal temporal and insula involvement in the other groups. Correlates of language symptoms and test scores also differed between the groups.

CONCLUSIONS

Language deficits exist in a substantial proportion of people with familial bvFTD across all three genetic groups. Significant atrophy is seen in the dominant perisylvian language areas and correlates with language impairments within each of the genetic groups. Improved understanding of the language phenotype in the main genetic bvFTD subtypes will be helpful in future studies, particularly in clinical trials where accurate stratification and monitoring of disease progression is required.

Mild behavioral impairment as a potential marker of predementia risk states in motor neuron diseases

BACKGROUND AND PURPOSE

Mild behavioral impairment (MBI) has been increasingly regarded as the neurobehavioral axis of predementia risk states, but a specific investigation of its detection as a potential marker of prodromal dementia in motor neuron diseases (MNDs) is still lacking. The aims of our study were therefore to explore MBI in MNDs both at onset and over the disease course, and to evaluate its relationship with baseline and longitudinal cognitive features.

METHODS

Sixty MND patients with cognitive/behavioral, mood, and motor examinations were recruited and followed longitudinally for up to 15 months. Associations between baseline MBI symptoms and clinical features were tested using the Spearman correlation coefficient. Based on longitudinal data, relative deltas of variation for each cognitive measure were generated, and linear regression models were then used to evaluate the role of baseline MBI symptoms in predicting longitudinal rates of cognitive decline.

RESULTS

At disease onset, the most impaired MBI domain was affective/emotional dysregulation, followed by impulse dyscontrol, apathy, and social inappropriateness. Greater MBI symptoms correlated with more severe baseline motor, cognitive/behavioral, and mood disturbances (p values from <0.001 to 0.05). Longitudinally, the greatest decline was observed in the affective/emotional dysregulation domain, followed by impulse dyscontrol, apathy, and social inappropriateness. Greater MBI symptoms at onset were significant predictors of more severe longitudinal cognitive decline in both amyotrophic lateral sclerosis (ALS)-specific and ALS-nonspecific functions (p values from <0.001 to 0.03).

CONCLUSIONS

MBI represents a valuable clinical marker of incident cognitive decline in MNDs, and its evaluation has good potential for detecting dementia in its preclinical/prodromal phase.

Distinct disease trajectories in frontotemporal dementia-motor neuron disease and behavioural variant frontotemporal dementia: A longitudinal study

BACKGROUND AND PURPOSE

The heterogeneity of cognitive and behavioural disturbances in frontotemporal dementia-motor neuron disease (FTD-MND), and clinical differences between FTD-MND and FTD subtypes, have been illustrated cross-sectionally. This study aimed to examine the FTD-MND disease trajectory by comparing clinical features of FTD-MND and the behavioural variant FTD (bvFTD) longitudinally.

METHODS

Neuropsychological and disease severity assessments were conducted in a cohort of FTD-MND (baseline, n = 42; follow-up, n = 18) and bvFTD (baseline, n = 116; follow-up, n = 111) using a longitudinal, case-control design. Age-, sex-, and education-matched controls (n = 52) were recruited. Predictors of clinical progression were analyzed. Voxel-based morphometry analysis was undertaken to investigate the progression of brain atrophy.

RESULTS

At baseline, FTD-MND was characterized by semantic and general cognition deficits, whereas bvFTD had greater behavioural disturbances. General cognition and language deteriorated in FTD-MND when followed longitudinally. Language deficits at baseline predicted cognitive deterioration and disease progression and correlated with progressive atrophy of language regions. Further deterioration in behaviour was evident in bvFTD over time. The rate of disease progression (i.e., general cognition, semantic association, and disease severity) was significantly faster in FTD-MND than in bvFTD.

CONCLUSIONS

FTD-MND and bvFTD appear to have distinct disease trajectories, with more rapid progression in FTD-MND. Language impairments should be closely monitored in FTD-MND as potential predictors of cognitive deterioration and disease progression.

Primary progressive aphasia and motor neuron disease: A review

Background

This study aims at reviewing, within the framework of motor neuron disease-frontotemporal degeneration (MND-FTD)-spectrum disorders, evidence on the co-occurrence between primary progressive aphasia (PPA) and MND in order to profile such a complex at pathological, genetic and clinical levels.

Methods

This review was pre-registered (osf.io/ds8m4) and performed in accordance with the 2020 PRISMA guidelines. Case reports/series and group studies were included if addressing (1) progressive non-fluent aphasia (PNFA) or semantic dementia (SD) with MND or (2) MND patients with co-morbid PNFA/SD.

Results

Out of 546 initial records, 56 studies were included. As to case reports/series (N = 35), which included 61 PPA-MND patients, the following findings yielded: (1) PNFA is more frequent than SD in PPA-MND; (2) in PPA-MND, the most prevalent motor phenotypes are amyotrophic lateral sclerosis and predominant-upper MND, with bulbar involvement being ubiquitous; (3) extrapyramidal features are moderately frequent in PPA-MND; (4) PPA-MND patients usually display frontotemporal, left-greater-than-right involvement; (5) TDP-43-B is the typical pathological substrate of PPA-MND; (6) TBK1 mutations represent the most frequent genetic risk factors for PPA-MND.

As to group studies, including 121 patients, proportional meta-analytic procedures revealed that: (1) the lifetime prevalence of MND in PPA is 6%; (2) PPA occurs in 19% of patients with co-morbid MND and FTD; (3) MND is more frequent in PNFA (10%) than in SD patients (3%).

Discussion

Insights herewith delivered into the clinical, neuropathological and genetic features of PPA-MND patients prompt further investigations aimed at improving clinical practice within the MND-FTD spectrum.

Anomia is present pre-symptomatically in frontotemporal dementia due to MAPT mutations

INTRODUCTION

A third of frontotemporal dementia (FTD) is caused by an autosomal-dominant genetic mutation in one of three genes: microtubule-associated protein tau (MAPT), chromosome 9 open reading frame 72 (C9orf72) and progranulin (GRN). Prior studies of prodromal FTD have identified impaired executive function and social cognition early in the disease but few have studied naming in detail.

METHODS

We investigated performance on the Boston Naming Test (BNT) in the GENetic Frontotemporal dementia Initiative cohort of 499 mutation carriers and 248 mutation-negative controls divided across three genetic groups: C9orf72, MAPT and GRN. Mutation carriers were further divided into 3 groups according to their global CDR plus NACC FTLD score: 0 (asymptomatic), 0.5 (prodromal) and 1 + (fully symptomatic). Groups were compared using a bootstrapped linear regression model, adjusting for age, sex, language and education. Finally, we identified neural correlates of anomia within carriers of each genetic group using a voxel-based morphometry analysis.

RESULTS

All symptomatic groups performed worse on the BNT than controls with the MAPT symptomatic group scoring the worst. Furthermore, MAPT asymptomatic and prodromal groups performed significantly worse than controls. Correlates of anomia in MAPT mutation carriers included bilateral anterior temporal lobe regions and the anterior insula. Similar bilateral anterior temporal lobe involvement was seen in C9orf72 mutation carriers as well as more widespread left frontal atrophy. In GRN mutation carriers, neural correlates were limited to the left hemisphere, and involved frontal, temporal, insula and striatal regions.

CONCLUSION

This study suggests the development of early anomia in MAPT mutation carriers, likely to be associated with impaired semantic knowledge. Clinical trials focused on the prodromal period within individuals with MAPT mutations should use language tasks, such as the BNT for patient stratification and as outcome measures.

Primary Progressive Aphasia Presenting With Neuropsychiatric Symptoms

We describe a case of primary progressive aphasia (PPA) with an underlying neurodegenerative motor disorder (possible ALS or PSP), presenting with symptoms of irritability and frustration, that were misdiagnosed and treated as a primary psychiatric disorder, i.e. depression. PPA is a rare neurodegenerative disorder characterized by insidious onset and gradual progression of speech and language impairment. We emphasize that PPA can initially masquerade as or be accompanied by neuropsychiatric symptoms potentially leading to misdiagnosis. Most prevalent neuropsychiatric symptoms reported in the PPA literature are agitation, depression, anxiety, apathy, irritability, abnormal appetite and disinhibition. To ensure early diagnosis of PPA, if a patient presents with new psychiatric symptoms accompanied by new onset speech and/or language impairment, referral to a specialist (i.e., neurologist and/or speech-language pathologist) is recommended.

Amyotrophic Lateral Sclerosis-Frontotemporal Dementia: Shared and Divergent Neural Correlates Across the Clinical Spectrum

BACKGROUND AND OBJECTIVES

A significant overlap between amyotrophic lateral sclerosis (ALS) and behavioral variant of frontotemporal dementia (bvFTD) has been observed at clinical, genetic, and pathologic levels. Within this continuum of presentations, the presence of mild cognitive or behavioral symptoms in patients with ALS has been consistently reported, although it is unclear whether this is to be considered a distinct phenotype or rather a natural evolution of ALS. Here, we used mathematical modeling of MRI connectomic data to decipher common and divergent neural correlates across the ALS-frontotemporal dementia (FTD) spectrum.

METHODS

We included 83 patients with ALS, 35 patients with bvFTD, and 61 healthy controls, who underwent clinical, cognitive, and MRI assessments. Patients with ALS were classified according to the revised Strong criteria into 54 ALS with only motor deficits (ALS-cn), 21 ALS with cognitive or behavioral involvement (ALS-ci/bi), and 8 ALS with bvFTD (ALS-FTD). First, we assessed the functional and structural connectivity patterns across the ALS-FTD spectrum. Second, we investigated whether and where MRI connectivity alterations of patients with ALS with any degree of cognitive impairment (i.e., ALS-ci/bi and ALS-FTD) resembled more the pattern of damage of one (ALS-cn) or the other end (bvFTD) of the spectrum, moving from group-level to single-subject analysis.

RESULTS

As compared with controls, extensive structural and functional disruption of the frontotemporal and parietal networks characterized bvFTD (bvFTD-like pattern), while a more focal structural damage within the sensorimotor-basal ganglia areas characterized ALS-cn (ALS-cn-like pattern). ALS-ci/bi patients demonstrated an ALS-cn-like pattern of structural damage, diverging from ALS-cn with similar motor impairment for the presence of enhanced functional connectivity within sensorimotor areas and decreased functional connectivity within the bvFTD-like pattern. On the other hand, patients with ALS-FTD resembled both structurally and functionally the bvFTD-like pattern of damage with, in addition, the structural ALS-cn-like damage in the motor areas.

DISCUSSION

Our findings suggest a maladaptive role of functional rearrangements in ALS-ci/bi concomitantly with similar structural alterations compared to ALS-cn, supporting the hypothesis that ALS-ci/bi might be considered as a phenotypic variant of ALS, rather than a consequence of disease worsening.

Loss of "insight" into behavioral changes in ALS: Differences across cognitive profiles

OBJECTIVE

Behavioral impairment occurs in amyotrophic lateral sclerosis (ALS) and ALS-fronto-temporal dementia (ALS-FTD). It has been proposed that ALS patients without FTD retain an awareness of their behavioral impairment while ALS-FTD patients lose this awareness (referred to as retention vs. loss of "insight"). Loss of insight has not yet been studied across the entire ALS-FTD spectrum; our study addresses this gap by including patients with all the ALS cognitive-behavioral profiles.

METHODS

Eighty-three ALS patients (and their informants) took part in this bicentric study involving two German recruitment sites. Patients and informants completed the Frontal Systems Behavior Scale covering the domains of apathy, disinhibition, and executive dysfunctioning. Patients were classified into five groups according to the Strong and Rascovsky criteria: cognitively unimpaired (ALSni), cognitively impaired without dementia (ALSci), behaviorally impaired (ALSbi), a combination of behaviorally and cognitively impaired (ALScbi), and ALS-FTD. We applied Bayesian two-way ANOVA to test whether there were subgroup differences regarding insight into their behavioral decline.

RESULTS

All patient subgroups experienced behavioral decline (Bayes factor > 3). Only ALS-FTD patients lost insight into disinhibition and executive dysfunctioning. ALSbi patients exhibited worse insight than ALSni and ALSci patients (Bayes factor > 10). Evidence regarding the ALScbi patients was inconclusive. Higher IQ was associated with worse insight (Bayes factor > 3).

CONCLUSIONS

Our findings provide solid support for the notion that ALS patients without dementia experience behavioral decline regardless of their cognitive-behavioral profile and retain different levels of insight into this decline. The inverse association of premorbid verbal intelligence with insight was unexpected, leaving room for further investigation.

Speech and language impairments in behavioral variant frontotemporal dementia: A systematic review

Although behavioral variant frontotemporal dementia (bvFTD) is classically defined by behavioral and socio-emotional changes, impairments often extend to other cognitive functions. These include early speech and language deficits related to the disease's core neural disruptions. Yet, their scope and clinical relevance remains poorly understood. This systematic review characterizes such disturbances in bvFTD, considering clinically, neuroanatomically, genetically, and neuropathologically defined subgroups. We included 181 experimental studies, with at least 5 bvFTD patients diagnosed using accepted criteria, comparing speech and language outcomes between bvFTD patients and healthy controls or between bvFTD subgroups. Results reveal extensive and heterogeneous deficits across cohorts, with (a) consistent lexico-semantic, reading & writing, and prosodic impairments; (b) inconsistent deficits in motor speech and grammar; and (c) relative preservation of phonological skills. Also, preliminary findings suggest that the severity of speech and language deficits might be associated with global cognitive impairment, predominantly temporal or fronto-temporal atrophy and MAPT mutations (vs C9orf72). Although under-recognized, these impairments contribute to patient characterization and phenotyping, while potentially informing diagnosis and management.

Tackling clinical heterogeneity across the amyotrophic lateral sclerosis-frontotemporal dementia spectrum using a transdiagnostic approach

The disease syndromes of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) display considerable clinical, genetic and pathological overlap, yet mounting evidence indicates substantial differences in progression and survival. To date, there has been limited examination of how profiles of brain atrophy might differ between clinical phenotypes. Here, we address this longstanding gap in the literature by assessing cortical and subcortical grey and white matter volumes on structural MRI in a large cohort of 209 participants. Cognitive and behavioural changes were assessed using the Addenbrooke’s Cognitive Examination and the Cambridge Behavioural Inventory. Relative to 58 controls, behavioural variant FTD (n = 58) and ALS–FTD (n = 41) patients displayed extensive atrophy of frontoinsular, cingulate, temporal and motor cortices, with marked subcortical atrophy targeting the hippocampus, amygdala, thalamus and striatum, with atrophy further extended to the brainstem, pons and cerebellum in the latter group. At the other end of the spectrum, pure-ALS patients (n = 52) displayed considerable frontoparietal atrophy, including right insular and motor cortices and pons and brainstem regions. Subcortical regions included the bilateral pallidum and putamen, but to a lesser degree than in the ALS–FTD and behavioural variant FTD groups. Across the spectrum the most affected region in all three groups was the insula, and specifically the anterior part (76–90% lower than controls). Direct comparison of the patient groups revealed disproportionate temporal atrophy and widespread subcortical involvement in ALS–FTD relative to pure-ALS. In contrast, pure-ALS displayed significantly greater parietal atrophy. Both behavioural variant FTD and ALS–FTD were characterized by volume decrease in the frontal lobes relative to pure-ALS. The motor cortex and insula emerged as differentiating structures between clinical syndromes, with bilateral motor cortex atrophy more pronounced in ALS–FTD compared with pure-ALS, and greater left motor cortex and insula atrophy relative to behavioural variant FTD. Taking a transdiagnostic approach, we found significant associations between abnormal behaviour and volume loss in a predominantly frontoinsular network involving the amygdala, striatum and thalamus. Our findings demonstrate the presence of distinct atrophy profiles across the ALS–FTD spectrum, with key structures including the motor cortex and insula. Notably, our results point to subcortical involvement in the origin of behavioural disturbances, potentially accounting for the marked phenotypic variability typically observed across the spectrum.

Validation of The Edinburgh cognitive and behavioural ALS screen (ECAS) in behavioural variant frontotemporal dementia and Alzheimer's disease

The Edinburgh Cognitive and Behavioural ALS Screen (ECAS) was developed to assess cognitive and behavioural changes in an anterior frontotemporal syndrome (executive functions, language, fluency and behaviour), common in Amyotrophic Lateral Sclerosis (ALS) and also assesses posterior cerebral dysfunction (memory and visuospatial abilities).

OBJECTIVES

To validate the ECAS in behavioural variant Frontotemporal Dementia (bvFTD) without ALS, as compared with Alzheimer's disease (AD), against comprehensive neuropsychological assessment. Compare its sensitivity to that of the Addenbrooke's Cognitive Examination (ACE-III) and investigate behavioural changes in both types of dementia.

METHODS

Retrospective study of 16 people with bvFTD (without ALS), 32 with AD, and 48 healthy controls completed the ECAS, ACE-III and extensive neuropsychological assessment.

RESULTS

The ECAS showed higher sensitivity (94%) and marginally lower specificity (96%) than the ACE-III for both the bvFTD and AD groups. The anterior composite subscore was sensitive for bvFTD (94%), and slightly less so for AD (84%), while the posterior composite subscore was sensitive for AD (97%), and less so for bvFTD (75%). All people with bvFTD that were impaired on the ECAS total and anterior composite scores were also impaired on the anterior function's tests of the neuropsychological assessment. A cut-off of four or more behavioural domains affected differentiated well between the bvFTD and AD groups, while a qualitative analysis of the behavioural interview found different themes between groups.

CONCLUSIONS

The ECAS is a valid and sensitive assessment for bvFTD without ALS and for AD. The carer behavioural interview makes it particularly suitable to detect behavioural abnormalities related to frontal lobe disorders.

When it is not primary progressive aphasia: A scoping review of spoken language impairment in other neurodegenerative dementias

BACKGROUND

Progressive difficulties with spoken language occur across the spectrum of degenerative dementia. When not a primary presenting and dominant symptom, language difficulties may be overlooked in favor of more prominent cognitive, behavior, or motor deficits. The aim of this scoping review is to examine the extent and nature of the research evidence describing (1) the spoken language impairments found in non-language led dementias, (2) their impact on everyday living, and (3) the reported language interventions.

METHODS

We searched PubMed, MEDLINE, OVID-EMBASE, PsycINFO, and SpeechBITE using terms related to spoken language for the following dementia types: Parkinson's disease dementia (PDD), dementia with Lewy bodies (DLB), progressive supranuclear palsy (PSP), cortico-basal syndrome (CBS), behavior variant frontotemporal dementia (bvFTD), early-onset Alzheimer's disease (EOAD), posterior cortical atrophy (PCA), and motor neuron disease associated with FTD (MND+FTD). Risk of bias was assessed with the QualSyst tool.

RESULTS

Seventy-three eligible studies were included. A wide range of spoken language impairments were reported, involving both linguistic (e.g., syntactic processing) and other cognitive (e.g., sustained attention) underlying mechanisms. Although the severity of these deficits was scarcely reported, in some cases they manifested as non-fluent, dynamic, and global aphasias. No papers in the review described either the impact of these language impairments on everyday living or language therapies to treat them.

DISCUSSION

There is a need to understand better the level of disability produced by language impairment in people living with non-language-led dementias. Our findings suggest three calls for action: (1) research studies should assess the clinical relevance of any spoken language deficits examined, (2) both linguistic and cognitive underlying mechanisms should be fully described (to inform the design of effective language and behavioral interventions), and (3) trials of language therapy should be conducted in those groups of individuals where significant language impairment is proved.

Language in Behavioral Variant Frontotemporal Dementia: Another Stone to Be Turned in Latin America

Beyond canonical deficits in social cognition and interpersonal conduct, behavioral variant frontotemporal dementia (bvFTD) involves language difficulties in a substantial proportion of cases. However, since most evidence comes from high-income countries, the scope and relevance of language deficits in Latin American bvFTD samples remain poorly understood. As a first step toward reversing this scenario, we review studies reporting language measures in Latin American bvFTD cohorts relative to other groups. We identified 24 papers meeting systematic criteria, mainly targeting phonemic and semantic fluency, naming, semantic processing, and comprehension skills. The evidence shows widespread impairments in these domains, often related to overall cognitive disturbances. Some of these deficits may be as severe as in other diseases where they are more widely acknowledged, such as Alzheimer's disease. Considering the prevalence and informativeness of language deficits in bvFTD patients from other world regions, the need arises for more systematic research in Latin America, ideally spanning multiple domains, in diverse languages and dialects, with validated batteries. We outline key challenges and pathways of progress in this direction, laying the ground for a new regional research agenda on the disorder.

Cognitive and Behavioral Manifestations in ALS: Beyond Motor System Involvement

Amyotrophic lateral sclerosis (ALS) has long been considered to be a purely motor disorder. However, it has become apparent that many ALS patients develop cognitive and behavioral manifestations similar to frontotemporal dementia and the term amyotrophic lateral sclerosis-frontotemporal spectrum disorder (ALS-FTSD) is now used in these circumstances. This review is intended to be an overview of the cognitive and behavioral manifestations commonly encountered in ALS patients with the goal of improving case-oriented management in clinical practice. We introduce the principal ALS-FTSD subtypes and comment on their principal clinical manifestations, neuroimaging findings, neuropathological and genetic background, and summarize available therapeutic options. Diagnostic criteria for ALS-FTSD create distinct categories based on the type of neuropsychological manifestations, i.e., changes in behavior, impaired social cognition, executive dysfunction, and language or memory impairment. Cognitive impairment is found in up to 65%, while frank dementia affects about 15% of ALS patients. ALS motor and cognitive manifestations can worsen in parallel, becoming more pronounced when bulbar functions (affecting speech, swallowing, and salivation) are involved. Dementia can precede or develop after the appearance of motor symptoms. ALS-FTSD patients have a worse prognosis and shorter survival rates than patients with ALS or frontotemporal dementia alone. Important negative prognostic factors are behavioral and personality changes. From the clinician's perspective, there are five major distinguishable ALS-FTSD subtypes: ALS with cognitive impairment, ALS with behavioral impairment, ALS with combined cognitive and behavioral impairment, fully developed frontotemporal dementia in combination with ALS, and comorbid ALS and Alzheimer's disease. Although the most consistent ALS and ALS-FTSD pathology is a disturbance in transactive response DNA binding protein 43 kDa (TDP-43) metabolism, alterations in microtubule-associated tau protein metabolism have also been observed in ALS-FTSD. Early detection and careful monitoring of cognitive deficits in ALS are crucial for patient and caregiver support and enable personalized management of individual patient needs.

Non-primary progressive language impairment in neurodegenerative conditions: protocol for a scoping review

BACKGROUND

Progressive language difficulties arise in many neurodegenerative conditions, causing significant impact upon patients and families. This occurs most obviously in primary progressive aphasia (PPA) but can also occur within other forms of progressive disease. In these cases, language decline may be significant, but as they are not the presenting or dominant symptom, may be overlooked in favour of more prominent cognitive, behaviour or motor deficits. To date, there has been no systematic investigation into non-primary progressive aphasia. This scoping review aims to describe the currently reported language impairments found in non-language-led dementias and identify their clinical relevance, defined as the impact on everyday living. It also seeks to identify the reported interventions for language impairment in this patient group to-date.

METHOD

We will conduct a scoping review of published studies that have assessed and/or treated aphasia in people diagnosed with a neurodegenerative condition other than primary progressive aphasia. The systematic search will include the electronic databases PubMed, MEDLINE, OVID-EMBASE, PsycINFO, and speechBITE, using search terms for specific non-language-led dementia subtypes. Findings will be mapped and described according to the type of language difficulties identified and rehabilitation approaches employed. Intervention studies will be evaluated for their methodological rigour using validated scales.

DISCUSSION

This scoping review will provide an overview of the types of aphasia found in neurodegenerative conditions where language dysfunction is not the primary focus. Current treatment approaches (and gaps in the provision of treatment) will be identified.

Behavioural Variant Frontotemporal Dementia: Recent Advances in the Diagnosis and Understanding of the Disorder

Frontotemporal dementia (FTD), particularly the behavioural variant (bvFTD) form, has fascinated researchers. Recent years have seen an increasing interest in aspects of bvFTD that extend beyond the initial focus on cognitive changes and frontal executive dysfunction. Changes have been identified in aspects including fundamental changes in physiology and metabolism, and cognitive domains such as episodic memory. Work on social cognition has emphasised the importance of a breakdown in interpreting and expressing emotions, while the overlap between psychiatric disorders and bvFTD has been brought into focus by the finding of high rates of psychotic features in carriers of the c9orf72 gene expansion. We review these aspects in the chapter " Behavioural variant frontotemporal dementia: Recent advances in diagnosis and understanding of the disorder" and also potential markers of disease progression and early diagnosis that may aid in the development of treatment options, which have thus far eluded us.

Cognition and behaviour in frontotemporal dementia with and without amyotrophic lateral sclerosis

OBJECTIVE

The precise relationship between frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) is incompletely understood. The association has been described as a continuum, yet data suggest that this may be an oversimplification. Direct comparisons between patients who have behavioural variant FTD (bvFTD) with and without ALS are rare. This prospective comparative study aimed to determine whether there are phenotypic differences in cognition and behaviour between patients with FTD-ALS and bvFTD alone.

METHODS

Patients with bvFTD or FTD-ALS and healthy controls underwent neuropsychological testing, focusing on language, executive functions and social cognition. Behavioural change was measured through caregiver interview. Blood samples were screened for known FTD genes.

RESULTS

23 bvFTD, 20 FTD-ALS and 30 controls participated. On cognitive tests, highly significant differences were elicited between patients and controls, confirming the tests' sensitivities to FTD. bvFTD and FTD-ALS groups performed similarly, although with slightly greater difficulty in patients with ALS-FTD on category fluency and a sentence-ordering task that assesses grammar production. Patients with bvFTD demonstrated more widespread behavioural change, with more frequent disinhibition, impulsivity, loss of empathy and repetitive behaviours. Behaviour in FTD-ALS was dominated by apathy. The C9ORF72 repeat expansion was associated with poorer performance on language-related tasks.

CONCLUSIONS

Differences were elicited in cognition and behaviour between bvFTD and FTD-ALS, and patients carrying the C9ORF72 repeat expansion. The findings, which raise the possibility of phenotypic variation between bvFTD and FTD-ALS, have clinical implications for early detection of FTD-ALS and theoretical implications for the nature of the relationship between FTD and ALS.

Phenotypic variability in ALS-FTD and effect on survival

OBJECTIVE

To determine if survival and cognitive profile is affected by initial presentation in amyotrophic lateral sclerosis-frontotemporal dementia (ALS-FTD) (motor vs cognitive), we compared survival patterns in ALS-FTD based on initial phenotypic presentation and their cognitive profile compared to behavioral variant FTD (bvFTD).

METHODS

Cognitive/behavioral profiles were examined in 98 patients (59 ALS-FTD and 39 bvFTD). The initial presentation of ALS-FTD was categorized into either motor or cognitive. Survival was calculated from initial symptom onset. MRI brain atrophy patterns were examined using a validated visual rating scale.

RESULTS

In the ALS-FTD group, 41 (69%) patients were categorized as having an initial cognitive presentation and 18 (31%) a motor presentation. Patients with motor presentation experienced a significantly shorter median survival of 2.7 years compared to 4.4 years (p < 0.001) in those with a cognitive presentation. No differences between motor vs cognitive onset ALS-FTD were found on cognitive testing. When compared to bvFTD, ALS-FTD-cognitive presentation was characterized by reduced language function (p < 0.001), verbal fluency (p = 0.001), and naming (p = 0.007). Both motor and cognitive onset ALS-FTD showed reduced emotion processing (p = 0.01) and exhibited greater motor cortex and dorsal lateral prefrontal cortex atrophy than bvFTD. Increased motor cortex atrophy was associated with 1.5-fold reduction in survival.

CONCLUSIONS

Initial motor presentation in ALS-FTD leads to faster progression than in those with a cognitive presentation, despite similar overall cognitive deficits. These findings suggest that disease progression in ALS-FTD may be critically linked to physiologic and motor changes.

Right fronto-parietal white matter disruption contributes to speech impairments in amyotrophic lateral sclerosis

INTRODUCTION

Non-linguistic properties of speech are widely heterogeneous and require complex neurological integration. The association between white matter integrity and the severity of dysarthria was investigated in a group of patients diagnosed with amyotrophic lateral sclerosis (ALS).

METHODS

Thirty-six patients diagnosed with amyotrophic lateral sclerosis completed a magnetic resonance imaging protocol inclusive of diffusion-weighted images. A clinical assessment of pneumo-phono-articulatory abilities was conducted for each patient, and a composite score of residual speech capacity was calculated. Tract-Based Spatial Statistics was carried out to model the potential association between residual speech capacity and microstructural properties of white matter (fractional anisotropy, mean and radial diffusivity).

RESULTS

A significant negative association was found between residual speech capacity and mean diffusivity in a large white matter cluster located in frontal, parietal and right temporal regions. These subcortical areas were characterised by pathological microstructural disruption, as revealed by post hoc analyses.

CONCLUSIONS

Non-linguistic aspects of speech are associated with microstructural integrity of frontal, parietal and right temporal white matter in amyotrophic lateral sclerosis. Such mapping is consistent with the centres responsible of volitional control of speech and sensory feedback during non-linguistic speech production.

Development of the MiNDToolkit for management of cognitive and behavioral impairment in motor neuron disease

Aim: To develop structured guidance, recommendations and techniques for nonpharmacological management of cognitive and behavioral impairments in motor neuron disease, called the MiNDToolkit. Methods: A four-round-modified Delphi method was utilized (online and face-to-face meeting), supplemented by recent research, recommendations, expertise from allied health professionals, clinicians, researchers and clients. Results: Round 1 (N = 47) identified allied health professionals techniques. Round 2 (N = 23) and 3 (N = 19) used expert consensus, refining general focus, specific elements and techniques. Round 4 (N = 8) applied personal, lived and occupational experience, finalizing the general structure and content of specific techniques. Conclusion: The MiNDToolkit is composed of multiple tools to structure decision-making through flowcharts, decision trees and checklists, provide information about impairments, assessment recommendations and techniques or strategies for nonpharmacological management cognitive or behavioral impairments in motor neuron disease.

The Use of Biomarkers and Genetic Screening to Diagnose Frontotemporal Dementia: Evidence and Clinical Implications

Within the wide range of neurodegenerative brain diseases, the differential diagnosis of frontotemporal dementia (FTD) frequently poses a challenge. Often, signs and symptoms are not characteristic of the disease and may instead reflect atypical presentations. Consequently, the use of disease biomarkers is of importance to correctly identify the patients. Here, we describe how neuropsychological characteristics, neuroimaging and neurochemical biomarkers and screening for causal gene mutations can be used to differentiate FTD from other neurodegenerative diseases as well as to distinguish between FTD subtypes. Summarizing current evidence, we propose a stepwise approach in the diagnostic evaluation. Clinical consensus criteria that take into account a full neuropsychological examination have relatively good accuracy (sensitivity [se] 75–95%, specificity [sp] 82–95%) to diagnose FTD, although misdiagnosis (mostly AD) is common. Structural brain MRI (se 70–94%, sp 89–99%) and FDG PET (se 47–90%, sp 68–98%) or SPECT (se 36–100%, sp 41–100%) brain scans greatly increase diagnostic accuracy, showing greater involvement of frontal and anterior temporal lobes, with sparing of hippocampi and medial temporal lobes. If these results are inconclusive, we suggest detecting amyloid and tau cerebrospinal fluid (CSF) biomarkers that can indicate the presence of AD with good accuracy (se 74–100%, sp 82–97%). The use of P-tau₁₈₁ and the Aβ_1–42/Aβ_1–40 ratio significantly increases the accuracy of correctly identifying FTD vs. AD. Alternatively, an amyloid brain PET scan can be performed to differentiate FTD from AD. When autosomal dominant inheritance is suspected, or in early onset dementia, mutation screening of causal genes is indicated and may also be offered to at-risk family members. We have summarized genotype–phenotype correlations for several genes that are known to cause familial frontotemporal lobar degeneration, which is the neuropathological substrate of FTD. The genes most commonly associated with this disease (C9orf72, MAPT, GRN, TBK1) are discussed, as well as some less frequent ones (CHMP2B, VCP). Several other techniques, such as diffusion tensor imaging, tau PET imaging and measuring serum neurofilament levels, show promise for future implementation as diagnostic biomarkers.

Naming and conceptual understanding in frontotemporal dementia

Behavioural variant frontotemporal dementia (bvFTD) is characterised by behaviour change and impaired executive skills. There is growing evidence that naming difficulties may also be present but the basis for these is unclear. A primary semantic deficit has been proposed, although executive contributions to naming breakdown are also possible. The study aimed to improve understanding of the naming disorder in bvFTD through direct comparison with semantic dementia (SD), and examination of neural correlates. It aimed also to address current controversies about the role of the anterior temporal lobes in semantic memory. We studied 71 bvFTD and 32 SD patients. Naming data were elicited by two picture naming tests (one challenging and one less demanding) and word comprehension by word-picture matching. Structural magnetic resonance images were rated blind using a standardised visual rating scale. Around half of bvFTD patients showed impaired naming and 17% impaired word-picture matching. Deficits in bvFTD were less severe than in SD, but showed a similar pattern. There were strong inverse correlations between naming scores and atrophy in temporal structures, particularly temporal pole and fusiform gyrus. Word comprehension scores correlated more strongly with posterior than anterior temporal lobe atrophy in SD. Error analysis highlighted a significant relationship in both groups between associative-type responses and temporal pole atrophy. By contrast, ‘don't know’ responses, suggesting a loss of conceptual knowledge, correlated with more posterior temporal regions. There was some correlation in bvFTD between naming and executive test performance but not with frontal lobe atrophy. The findings support the view that naming problems can arise in bvFTD independently of patients' ‘frontal’ executive impairment and highlight clinical overlap between bvFTD and SD. We discuss the findings in relation to the hub and spoke model of semantic memory and argue against the notion of an anterior temporal lobe semantic hub.

Speech network regional involvement in bulbar ALS: a multimodal structural MRI study

Objective: To examine gray (GM) and white matter (WM) structural changes in regions of the speech network (SpN) in ALS patients with varying degree of bulbar disease. Methods: T1 and DTI images were obtained for 19 ALS participants and 13 neurologically-intact controls. Surface-based, volumetric, and DTI metrics were obtained for 6 regions-of-interest (ROIs) including the primary motor cortex (PMC), pars triangularis (parsT), pars opercularis (ParsO), posterior superior temporal gyrus (pSTG), and transverse temporal (TT). Disease-effects and brain-behavioral correlates between neuroanatomy and clinical measures of bulbar, limb, and overall disability were examined using linear models. Results: Structural changes were observed in the right oral and limb PMC and left ParsT, TT, and pSTG in ALS. Bulbar motor dysfunction was associated with WM abnormalities in the right oral PMC and left pSTG, and GM changes in bilateral TT. In contrast, symptom progression rate predicted GM and WM changes in bilateral pars opercularis (part of Broca's area). Grip strength and disease duration models were non-significant. Conclusions: The findings suggested that regions of the left-dominant SpN may be implicated in ALS and degeneration of these areas are related to bulbar disease severity. Involvement of regions that overlap across multiple connectomes such as Broca's area, however, may be dependent on the rate of disease progression. The work contributes to our understanding of bulbar ALS subtype, which is crucial for predicting disease progression, delivering targeted clinical care, and appropriate recruitment into clinical trials.

The underacknowledged PPA-ALS

Objective

To assess the incidence, heritability, and neuropathology of primary progressive aphasia (PPA) with amyotrophic lateral sclerosis (ALS) in a large Australian cohort.

Methods

A total of 130 patients with a primary nonfluent variant of PPA (nfvPPA) or semantic variant of PPA (svPPA) were assessed for concomitant ALS and a strong family history of neurodegenerative diseases (Goldman score ≤3). Neuropathologic examination was carried out in 28% (n = 36) of these PPA and PPA-ALS cases that had come to autopsy.

Results

ALS was identified in 18% of patients with nfvPPA and 5% of patients with svPPA. PPA-ALS but not PPA was found to have a strong family history. At autopsy, frontotemporal lobar degeneration (FTLD)–TDP was identified in 100% of nfvPPA-ALS cases, 100% of svPPA-ALS cases, 24% of nfvPPA cases, and 78% of svPPA cases. Clinicopathologic assessments revealed a significant association between a strong family history and underlying FTLD-TDP pathology. Pathogenic mutations in known frontotemporal dementia (FTD)/ALS genes were identified in 100% of these familial PPA cases but only 50% of familial PPA-ALS cases, suggesting the involvement of novel genetic variants in this underacknowledged phenotype.

Conclusion

The present study identified ALS in 12% of a large cohort of patients with nfvPPA and svPPA, which is comparable to the 10%–15% reported in FTD overall, indicating that a third of patients with FTD-ALS will have a predominant language profile. These findings highlight the importance of assessing for ALS in PPA, particularly since this is the only PPA phenotype in which a perfect clinicopathologic association has been reported in to date.

A case of progressive non-fluent aphasia as onset of amyotrophic lateral sclerosis with frontotemporal dementia

The association between Amyotrophic Lateral Sclerosis (ASL) and FrontoTemporal Dementia (FTD) is well known. Most of reports describing ASL-FTD cases show a strong association between ALS and the behavioural form of FTD. Conversely, the association between ALS and pure Semantic Dementia or Progressive Non-Fluent Aphasia (PNFA) is extremely rare, ranging from 1 to 3%. A clinical phenotype characterized by a rapidly progressive aphasic dementia and motoneuron disease (MND) has been described in few case reports; since the updating of PNFA diagnostic criteria in 2011, no clinical report has been related. We want to describe a case of patient presented, at the onset, as PNFA who developed, one year later, ALS with bulbar onset. The patient was screened for the main genes causing or associated with MND and/or dementia but no variants with a pathogenetic effect were observed.

Primary progressive aphasia and the FTD-MND spectrum disorders: clinical, pathological, and neuroimaging correlates

Objective: Behavioral variant frontotemporal dementia (bvFTD), is commonly considered the cognitive presentation of the frontotemporal dementia-motor neuron disease (FTD-MND) spectrum disorder. We evaluated the prevalence of primary progressive aphasia in a series of pathologically confirmed cases of FTD-MND spectrum. Methods: Pathologically confirmed cases of frontotemporal lobar degeneration-motor neuron disease (FTLD-MND) were obtained from the UCSF brain bank. Cases were analyzed for presence of language impairment via retrospective chart review of research visits that include neurologic exam, in-depth cognitive testing and magnetic resonance imaging (MRI) imaging. Forty one cases were included. Thirty two were diagnosed with FTD-MND, while nine cases were diagnosed as MND-only from clinical evaluation. Results: Ten FTLD-MND cases (31%) presented with prominent or isolated language involvement consistent with a diagnosis of primary progressive aphasia (PPA), which we called progressive aphasia with motor neuron disease (PA-MND). Of these, three cases that mirrored the non-fluent variant of PPA (nfvPPA) were named nfvPA-MND. The imaging pattern of these nfvPA-MND showed atrophy strictly confined to the frontal and anterior temporal language cortical areas. Another group of seven cases that resembled patients with the semantic variant PPA (svPPA) were named svPA-MND. The group of svPPA-MND on imaging analysis showed selective atrophy of the temporal lobe and orbitofrontal cortex. Conclusions: Language impairment was a frequent phenotype of FTD-MND associated with focal atrophy patterns within the language networks. This data suggest patients with FTD-MND can present quite often with language phenotype of nfvPPA and svPPA, as opposed to exclusive bvFTD symptoms.