Frontotemporal Dysfunction and Dementia in Amyotrophic Lateral Sclerosis

Quality of life, cognitive and behavioural impairment in people with motor neuron disease: a systematic review

PURPOSE

Motor neuron disease (MND) is a neurodegenerative disease, progressively impacting function and self-perceived quality of life (QoL). Up to 50% of people with MND can present with cognitive and behavioural impairment, with an associated increase in caregiver burden or strain. However, there has been no systematic exploration of the relationship between QoL and cognitive or behavioural impairment in MND. The aim was to determine if there is a relationship between QoL and cognitive/behavioural impairment in MND, while also supplementarily looking to determine the types of cognitive/behavioural and QoL measures utilised in these studies.

METHODS

A systematic search was performed across multiple databases (PsychINFO, Embase, Medline, AMED) for research published up to the date of February 22, 2023. Studies utilising quantitative methods of measuring QoL, cognitive/behavioural functioning/impairment were included. Findings examining relationships between QoL-cognitive/behavioural impairment were extracted and synthesised.

RESULTS

A total of 488 studies were identified, with 14 studies included in the systematic review. All 14 studies were observational (11 cross-sectional, 3 longitudinal). 13 studies utilised MND non-specific measures, particularly in relation to QoL and cognitive impairment. Of 8 studies measuring behavioural impairment 62.5% (N = 5) found either a lower QoL difference or association. Only 33.3% (N = 4) of 12 studies measuring cognitive impairment found a lower QoL difference or association.

CONCLUSIONS

This systematic review shows that behavioural impairment may have an impact on QoL in MND. There is variability in types of assessments used to measure QoL and also cognitive/behavioural impairment, most of which are disease-non-specific. Recommendations for future research are to use comprehensive disease-specific, multidomain measures to further elucidate the QoL-cognitive/behavioural impairment relationship.

History of ALS and the competing theories on pathogenesis: IFCN handbook chapter

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disorder of the human motor system, first described in the 19th Century. The etiology of ALS appears to be multifactorial, with a complex interaction of genetic, epigenetic, and environmental factors underlying the onset of disease. Importantly, there are no known naturally occurring animal models, and transgenic mouse models fail to faithfully reproduce ALS as it manifests in patients. Debate as to the site of onset of ALS remain, with three competing theories proposed, including (i) the dying-forward hypothesis, whereby motor neuron degeneration is mediated by hyperexcitable corticomotoneurons via an anterograde transsynaptic excitotoxic mechanism, (ii) dying-back hypothesis, proposing the ALS begins in the peripheral nervous system with a toxic factor(s) retrogradely transported into the central nervous system and mediating upper motor neuron dysfunction, and (iii) independent hypothesis, suggesting that upper and lower motor neuron degenerated independently. Transcranial magnetic stimulation studies, along with pathological and genetic findings have supported the dying forward hypothesis theory, although the science is yet to be settled. The review provides a historical overview of ALS, discusses phenotypes and likely pathogenic mechanisms.

Pathophysiological Underpinnings of Extra-Motor Neurodegeneration in Amyotrophic Lateral Sclerosis: New Insights From Biomarker Studies

Amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) lie at opposing ends of a clinical, genetic, and neuropathological continuum. In the last decade, it has become clear that cognitive and behavioral changes in patients with ALS are more frequent than previously recognized. Significantly, these non-motor features can impact the diagnosis, prognosis, and management of ALS. Partially overlapping neuropathological staging systems have been proposed to describe the distribution of TAR DNA-binding protein 43 (TDP-43) aggregates outside the corticospinal tract. However, the relationship between TDP-43 inclusions and neurodegeneration is not absolute and other pathophysiological processes, such as neuroinflammation (with a prominent role of microglia), cortical hyperexcitability, and synaptic dysfunction also play a central role in ALS pathophysiology. In the last decade, imaging and biofluid biomarker studies have revealed important insights into the pathophysiological underpinnings of extra-motor neurodegeneration in the ALS-FTLD continuum. In this review, we first summarize the clinical and pathophysiological correlates of extra-motor neurodegeneration in ALS. Next, we discuss the diagnostic and prognostic value of biomarkers in ALS and their potential to characterize extra-motor neurodegeneration. Finally, we debate about how biomarkers could improve the diagnosis and classification of ALS. Emerging imaging biomarkers of extra-motor neurodegeneration that enable the monitoring of disease progression are particularly promising. In addition, a growing arsenal of biofluid biomarkers linked to neurodegeneration and neuroinflammation are improving the diagnostic accuracy and identification of patients with a faster progression rate. The development and validation of biomarkers that detect the pathological aggregates of TDP-43 in vivo are notably expected to further elucidate the pathophysiological underpinnings of extra-motor neurodegeneration in ALS. Novel biomarkers tracking the different aspects of ALS pathophysiology are paving the way to precision medicine approaches in the ALS-FTLD continuum. These are essential steps to improve the diagnosis and staging of ALS and the design of clinical trials testing novel disease-modifying treatments.

Prognosis of amyotrophic lateral sclerosis with cognitive and behavioural changes based on a sixty-month longitudinal follow-up

OBJECTIVE

Approximately 50% of amyotrophic lateral sclerosis (ALS) patients have cognitive and behavioural dysfunction in varying degrees and forms. Previous studies have shown that cognitive and behavioural changes may indicate a poor prognosis, and cognitive function gradually deteriorates over the course of disease, but the results of different studies have been inconsistent. In addition, there are relatively limited long-term follow-up studies tracking death as an endpoint. The purpose of this study was to investigate the clinical prognostic characteristics of ALS patients with cognitive behavioural changes through long-term follow-up in a cohort.

METHODS

A total of 87 ALS patients from 2014 to 2015 in the Third Hospital of Peking University were selected and divided into a pure ALS group, an ALS with behavioural variant of frontotemporal dementia (ALS-bvFTD) group, and an ALS with cognitive and behaviour changes group. All patients were followed up for 60 months. The main end point was death and tracheotomy.

RESULTS

There was no significant difference in survival curve between pure ALS and ALS with cognitive and behavioural change group, but the survival time of ALS-bvFTD group was significantly lower than the other two groups (P < 0.001). For those who was followed up to the endpoint, the survival time of the ALS-bvFTD group was significantly shorter than that of the pure ALS group (t = 5.33, p < 0.001) or the ALS with cognitive and behaviour changes group (t = 4.25, p < 0.001). The progression rate of ALS Functional Rating Scale-Revised (FRS-R) scores from recruitment to endpoint was significantly faster in the ALS-bvFTD group than in the pure ALS group (z = 2.68, p = 0.01) or the ALS with cognitive and behavioural changes group (z = 2.75, p = 0.01). There was no significant difference in survival time (t = 0.52, P = 0.60) or FRS-R score progression rate (z = 0.31, p = 0.76) between the pure ALS group and the ALS with cognitive and behavioural changes group. The total Edinburgh Cognitive and Behavioural Amyotrophic Lateral Sclerosis Screen (ECAS) score was positively correlated with survival time (r = 0.38, p = 0.01).

CONCLUSION

ALS-bvFTD patients have shorter survival time. The total ECAS score may be correlated with survival time.

The Dying Forward Hypothesis of ALS: Tracing Its History

The site of origin of amyotrophic lateral sclerosis (ALS), although unsettled, is increasingly recognized as being cortico-fugal, which is a dying-forward process primarily starting in the corticomotoneuronal system. A variety of iterations of this concept date back to over 150 years. Recently, the hallmark TAR DNA-binding protein 43 (TDP-43) pathology, seen in >95% of patients with ALS, has been shown to be largely restricted to corticofugal projecting neurons (“dying forward”). Possibly, soluble but toxic cytoplasmic TDP-43 could enter the axoplasm of Betz cells, subsequently causing dysregulation of nuclear protein in the lower brainstem and spinal cord anterior horn cells. As the disease progresses, cortical involvement in ALS becomes widespread, including or starting with frontotemporal dementia, implying a broader view of ALS as a brain disease. The onset at the motor and premotor cortices should be considered a nidus at the edge of multiple cortical networks which eventually become disrupted, causing failure of a widespread cortical connectome.

Amyotrophic lateral sclerosis, dysarthria, and language disorders - type of research and approaches in different areas: an integrative literature review

ABSTRACT Purpose: to identify the knowledge produced in national and international researches on speech and language disorders in Amyotrophic Lateral Sclerosis, regarding the type of research and approach in different areas. Methods: an integrative review performed on databases, using the following descriptors: Amyotrophic Lateral Sclerosis, Dysarthria, Language Disorders, Speech Production Measurement and Speech Disorders. The inclusion criteria covered articles that addressed motor speech and language disorders from 2013 to 2018, excluding duplications, and categorizing valid articles for analysis. Results: 83 articles were selected, after screening the titles and abstracts. A large scientific production from different countries and areas, mainly Speech Therapy and Neurology, was found. Most of them was clinical research (65.06%), with a main focus on speech motor disorders (42.16%), speech and language motor disorders, cognition and behavior (27.71%), and language disorders (12.06%). Conclusion: researches found were mostly clinical and aimed at determining the diagnosis of disorders in different areas of knowledge. With regard to communication, few studies have been found in Brazil, and international studies addressed high technology. The results confirmed the heterogeneous nature of the disease, which shows, in addition to motor impairment of speech, cognitive, behavioral and language impairments.

Is it accurate to classify ALS as a neuromuscular disorder?

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a fatal disorder characterized by the progressive loss of upper and lower motor neurons. ALS has traditionally been classified within the domain of neuromuscular diseases, which are a unique spectrum of disorders that predominantly affect the peripheral nervous system. However, over the past decades compounding evidence has emerged that there is extensive involvement of the central nervous system. Therefore, one can question whether it remains accurate to classify ALS as a neuromuscular disorder.

AREAS COVERED

In this review, the authors sought to discuss current approaches toward disease classification and how we should classify ALS based on novel insights from clinical, imaging, pathophysiological, neuropathological and genetic studies.

EXPERT OPINION

ALS exhibits the cardinal features of a neurodegenerative disease. Therefore, classifying ALS as a neuromuscular disease in the strict sense has become untenable. Diagnosing ALS however does require significant neuromuscular expertise and therefore neuromuscular specialists remain best equipped to evaluate this category of patients. Designating motor neuron diseases as a separate category in the ICD-11 is justified and adequately deals with this issue. However, to drive effective therapy development the fields of motor neuron disease and neurodegenerative disorders must come together.

Signal-detection analysis of the WMS faces subtest: Results in amyotrophic lateral sclerosis patients

About 30% of patients with amyotrophic lateral sclerosis (ALS) suffer from cognitive impairment and 10-15% suffer from frontotemporal dementia (FTD). Due to the patients' reduced motor function, a neuropsychological assessment with a low motor demand can be an advantage when evaluating patients, aiding its application. The present work has studied the usefulness of the Faces subtest of the Wechsler Memory Scale in 42 patients with ALS and 42 healthy volunteers applying Holdnack's Two-High Threshold model. The ALS group performed significantly worse in immediate and delayed discriminability. With respect to the presence of cognitive impairment, it seemed to be independent of the indexes proposed by Holdnack and Delis. On the other hand, motor problems were associated with delayed recognition while behavior alterations were linked to problems with delayed discriminability. ALS patients do not express differences in the bias index, in line with other types of previously studied pathologies.

Structural and functional papez circuit integrity in amyotrophic lateral sclerosis

Cognitive impairment in amyotrophic lateral sclerosis (ALS) is heterogeneous but now recognized as a feature in non-demented patients and no longer exclusively attributed to executive dysfunction. However, despite common reports of temporal lobe changes and memory deficits in ALS, episodic memory has been less explored. In the current study, we examined how the Papez circuit-a circuit known to participate in memory processes-is structurally and functionally affected in ALS patients (n = 20) compared with healthy controls (n = 15), and whether these changes correlated with a commonly used clinical measure of episodic memory. Our multimodal MRI approach (cortical volume, voxel-based morphometry, diffusion tensor imaging and resting state functional magnetic resonance) showed reduced gray matter in left hippocampus, left entorhinal cortex and right posterior cingulate as well as increased white matter fractional anisotropy and decreased mean diffusivity in the left cingulum bundle (hippocampal part) of ALS patients compared with controls. Interestingly, thalamus, mammillary bodies and fornix were preserved. Finally, we report a decreased functional connectivity in ALS patients in bilateral hippocampus, bilateral anterior and posterior parahippocampal gyrus and posterior cingulate. The results revealed that ALS patients showed statistically significant structural changes, but more important, widespread prominent functional connectivity abnormalities across the regions comprising the Papez circuit. The decreased functional connectivity found in the Papez network may suggest these changes could be used to assess risk or assist early detection or development of memory symptoms in ALS patients even before structural changes are established.

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.

CSF sAPPβ, YKL-40, and NfL along the ALS-FTD spectrum

OBJECTIVE

To investigate the clinical utility of 3 CSF biomarkers along the clinical spectrum of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD).

METHODS

We analyzed 3 CSF biomarkers: the soluble β-fragment of amyloid precursor protein (sAPPβ), YKL-40, and neurofilament light (NfL) in FTD (n = 86), ALS (n = 38), and a group of age-matched cognitively normal controls (n = 49). Participants with FTD with a CSF profile of Alzheimer disease were excluded. We compared cross-sectional biomarker levels between groups, studied their correlation with cognitive and functional scales (global cognitive z score, frontotemporal lobar degeneration Clinical Dementia Rating, revised ALS Functional Rating Scale, and ALS progression rate), survival, and cortical thickness.

RESULTS

We found increased levels of YKL-40 and decreased levels of sAPPβ in both FTD and ALS groups compared to controls. The lowest sAPPβ levels and sAPPβ/YKL-40 ratio were found in the FTD group. In FTD, sAPPβ and the sAPPβ/YKL-40 ratio correlated with the disease severity. In the whole ALS-FTD spectrum, NfL levels and the NfL:sAPPβ ratio correlated with global cognitive performance (r = -0.41, p < 0.001 and r = -0.44, p < 0.001, respectively). In the ALS group, YKL-40 correlated with disease progression rate (r = 0.51, p = 0.001) and was independently associated with shorter survival. In both FTD and ALS groups, the sAPPβ/YKL-40 ratio showed a positive correlation with cortical thickness in frontotemporal regions.

CONCLUSIONS

sAPPβ, YKL-40, and NfL could represent valuable tools for the staging and prognosis of patients within the ALS-FTD clinical spectrum.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that CSF levels of sAPPβ, YKL-40, and NfL are useful to assess frontotemporal neurodegeneration and the progression rate in the ALS-FTD continuum.

Cognitive impairment in neuromuscular diseases: A systematic review

Neuromuscular diseases are multifactorial pathologies characterized by extensive muscle fiber damage that leads to the activation of satellite cells and to the exhaustion of their pool, with consequent impairment of neurobiological aspects, such as cognition and motor control. To review the knowledge and obtain a broad view of the cognitive impairment on Neuromuscular Diseases. Cognitive impairment in neuromuscular disease was explored; a literature search up to October 2017 was conducted, including experimental studies, case reports and reviews written in English. Keywords included Cognitive Impairment, Neuromuscular Diseases, Motor Neuron Diseases, Dystrophinopathies and Mitochondrial Disorders. Several cognitive evaluation scales, neuroimaging scans, genetic analysis and laboratory applications in neuromuscular diseases, especially when it comes to the Motor Neuron Diseases, Dystrophinopathies and Mitochondrial Disorders. In addition, organisms model using rats in the genetic analysis and laboratory applications to verify the cognitive and neuromuscular impacts. Several studies indicate that congenital molecular alterations in neuromuscular diseases promote cognitive dysfunctions. Understanding these mechanisms may in the future guide the proper management of the patient, evaluation, establishment of prognosis, choice of treatment and development of innovative interventions such as gene therapy.

Brain signature of mild stages of cognitive and behavioral impairment in amyotrophic lateral sclerosis

We aimed to assess the brain signature of cognitive and behavioral impairment in C9orf72-negative non-demented ALS patients. The study included 50 amyotrophic lateral sclerosis (ALS) patients (out of 75 initially recruited) and 38 healthy controls. High-resolution T1-weighted and spin-echo diffusion tensor images were acquired in a 3T MRI scanner. The multi atlas-based analysis protocol and the FreeSurfer tool were employed for gray matter assessment, and fiber tractography for white matter evaluation. Cognitively impaired ALS patients (n = 12) had bilateral amygdalae and left thalamic volumetric reduction compared to non-impaired ALS patients. Behaviorally impaired ALS patients (n = 14) had lower fractional anisotropy (FA) at the fornix in comparison with healthy subjects. These parameters did correlate with cognitive/behavioral scores, but not with motor-functional parameters in the ALS cohort. We believe that basal ganglia and fornix damage might be related to cognitive and behavioral impairment across ALS-frontotemporal dementia continuum. Also, distinct anatomical areas seem to influence the behavioral and cognitive status of these individuals.

OPTN p.Met468Arg and ATXN2 intermediate length polyQ extension in families with C9orf72 mediated amyotrophic lateral sclerosis and frontotemporal dementia

We have ascertained two families affected with familial amyotrophic lateral sclerosis (ALS) in which they both carry a hexanucleotide repeat expansion in the C9orf72 gene, specifically in individuals who also presented with frontotemporal dementia (FTD) or behavioral variant FTD (bvFTD). While some reports attribute this phenotypic heterogeneity to the C9orf72 expansion alone, we screened for additional genetic variation in known ALS-FTD genes that may also contribute to or modify the phenotypes. We performed genetic testing consisting of C9orf72 hexanucleotide expansion, ATXN2 polyglutamine (polyQ) expansion, and targeted next generation sequencing using the ONDRISeq, a gene panel consisting of 80 genes known to be associated with neurodegenerative diseases such as ALS, FTD, Alzheimer's disease, Parkinson's disease, and vascular cognitive impairment. In addition to the C9orf72 expansion, we observed an ATXN2 polyQ intermediate length expansion, and OPTN p.Met468Arg in patients who exhibited ALS and FTD or bvFTD. We conclude that the C9orf72 expansion likely explains much of the ALS-FTD phenotype; however, inheritance of these additional variants likely modifies the disease course and may provide further evidence for biologically relevant oligogenic inheritance in ALS.

Frequency-Specific Abnormalities of Intrinsic Functional Connectivity Strength among Patients with Amyotrophic Lateral Sclerosis: A Resting-State fMRI Study

The classical concept that amyotrophic lateral sclerosis (ALS) is a degenerative disorder characterized by the loss of upper and lower motor neurons is agreed. However, more and more studies have suggested the involvement of some extra-motor regions. The aim of this study is to investigate the frequency-related alteration pattern of intrinsic functional connectivity strength (FCS) at the voxel-wise level in the relatively early-stage of ALS on a whole brain scale. In this study, 21 patients with ALS and 21 well-matched healthy control subjects were enrolled to examine the intrinsic FCS in the different frequencies (slow-4: 0.027-0.073 Hz; slow-5: 0.01-0.027 Hz, and typical band: 0.01-0.1 Hz). Compared with the control subjects, the ALS patients showed a significantly decreased FCS in the left prefrontal cortex (PFC) and the bilateral superior frontal gyrus. In the slow-5 band, the patients with ALS showed decreased FCS in the left lingual gyrus, as well as increased FCS in the left postcentral gyrus/paracentral lobule (PoCG/PARC). In the slow-4 band, the ALS patients presented decreased FCS in the left and right ventrolateral PFC. Moreover, the increased FCS in the left PoCG/PARC in the slow-5 band was positively correlated with the ALSFRS-r score (P = 0.015). Our results demonstrated that the FCS changes in ALS were wide spread and frequency dependent. These findings may provide some evidences that ALS patients have the consistent impairment in some extra-motor regions at a relatively early-stage.

Usefulness of diffusion tensor imaging in amyotrophic lateral sclerosis: potential biomarker and association with the cognitive profile

Methods

This was a case-control study conducted from December 1, 2012 to December 1, 2014. Clinical and demographic data were recorded. A neuropsychological test battery adapted to ALS patients was used. An MRI with DTI was performed in all patients and fractional anisotropy (FA) was analyzed in the white matter using the tract based spatial statistics program.

Results

Twenty-four patients with ALS (15 females, mean age 66.9 + -2.3) and 13 healthy controls (four females, average age 66.9 + - 2) were included. The DTI showed white matter damage in ALS patients vs. healthy controls (p < 0.001).

Discussion

In our preliminary study the alterations of white matter in DTI were significantly associated with cognitive impairment in patients with ALS.

Amyotrophic lateral sclerosis - frontotemporal spectrum disorder (ALS-FTSD): Revised diagnostic criteria

This article presents the revised consensus criteria for the diagnosis of frontotemporal dysfunction in amyotrophic lateral sclerosis (ALS) based on an international research workshop on frontotemporal dementia (FTD) and ALS held in London, Canada in June 2015. Since the publication of the Strong criteria, there have been considerable advances in the understanding of the neuropsychological profile of patients with ALS. Not only is the breadth and depth of neuropsychological findings broader than previously recognised - - including deficits in social cognition and language - but mixed deficits may also occur. Evidence now shows that the neuropsychological deficits in ALS are extremely heterogeneous, affecting over 50% of persons with ALS. When present, these deficits significantly and adversely impact patient survival. It is the recognition of this clinical heterogeneity in association with neuroimaging, genetic and neuropathological advances that has led to the current re-conceptualisation that neuropsychological deficits in ALS fall along a spectrum. These revised consensus criteria expand upon those of 2009 and embrace the concept of the frontotemporal spectrum disorder of ALS (ALS-FTSD).

The Ontario Neurodegenerative Disease Research Initiative (ONDRI)

Because individuals develop dementia as a manifestation of neurodegenerative or neurovascular disorder, there is a need to develop reliable approaches to their identification. We are undertaking an observational study (Ontario Neurodegenerative Disease Research Initiative [ONDRI]) that includes genomics, neuroimaging, and assessments of cognition as well as language, speech, gait, retinal imaging, and eye tracking. Disorders studied include Alzheimer’s disease, amyotrophic lateral sclerosis, frontotemporal dementia, Parkinson’s disease, and vascular cognitive impairment. Data from ONDRI will be collected into the Brain-CODE database to facilitate correlative analysis. ONDRI will provide a repertoire of endophenotyped individuals that will be a unique, publicly available resource.

White matter structural network abnormalities underlie executive dysfunction in amyotrophic lateral sclerosis

Research in amyotrophic lateral sclerosis (ALS) suggests that executive dysfunction, a prevalent cognitive feature of the disease, is associated with abnormal structural connectivity and white matter integrity. In this exploratory study, we investigated the white matter constructs of executive dysfunction, and attempted to detect structural abnormalities specific to cognitively impaired ALS patients. Eighteen ALS patients and 22 age and education matched healthy controls underwent magnetic resonance imaging on a 4.7 Tesla scanner and completed neuropsychometric testing. ALS patients were categorized into ALS cognitively impaired (ALSci, n = 9) and ALS cognitively competent (ALScc, n = 5) groups. Tract-based spatial statistics and connectomics were used to compare white matter integrity and structural connectivity of ALSci and ALScc patients. Executive function performance was correlated with white matter FA and network metrics within the ALS group. Executive function performance in the ALS group correlated with global and local network properties, as well as FA, in regions throughout the brain, with a high predilection for the frontal lobe. ALSci patients displayed altered local connectivity and structural integrity in these same frontal regions that correlated with executive dysfunction. Our results suggest that executive dysfunction in ALS is related to frontal network disconnectivity, which potentially mediates domain-specific, or generalized cognitive impairment, depending on the degree of global network disruption. Furthermore, reported co-localization of decreased network connectivity and diminished white matter integrity suggests white matter pathology underlies this topological disruption. We conclude that executive dysfunction in ALSci is associated with frontal and global network disconnectivity, underlined by diminished white matter integrity. Hum Brain Mapp 38:1249-1268, 2017. © 2016 Wiley Periodicals, Inc.

Physician-assisted death: A Canada-wide survey of ALS health care providers

OBJECTIVE

To survey amyotrophic lateral sclerosis (ALS) health care providers to determine attitudes regarding physician-assisted death (PAD) after the Supreme Court of Canada (SCC) invalidated the Criminal Code provisions that prohibit PAD in February 2015.

METHODS

We conducted a Canada-wide survey of physicians and allied health professionals (AHP) involved in the care of patients with ALS on their opinions regarding (1) the SCC ruling, (2) their willingness to participate in PAD, and (3) the PAD implementation process for patients with ALS.

RESULTS

We received 231 responses from ALS health care providers representing all 15 academic ALS centers in Canada, with an overall response rate for invited participants of 74%. The majority of physicians and AHP agreed with the SCC ruling and believed that patients with moderate and severe stage ALS should have access to PAD; however, most physicians would not provide a lethal prescription or injection to an eligible patient. They preferred the patient obtain a second opinion to confirm eligibility, have a psychiatric assessment, and then be referred to a third party to administer PAD. The majority of respondents felt unprepared for the initiation of this program and favored the development of PAD training modules and guidelines.

CONCLUSIONS

ALS health care providers support the SCC decision and the majority believe PAD should be available to patients with moderate to severe ALS with physical or emotional suffering. However, few clinicians are willing to directly provide PAD and additional training and guidelines are required before implementation in Canada.