Changes in cognition and behaviour in amyotrophic lateral sclerosis: nature of impairment and implications for assessment

C9ORF72 and the FTD-ALS spectrum: A systematic review of neuroimaging studies

Objective

To perform a systematic review of the literature on the neuroimaging investigation of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) associated with C9ORF72 mutation.

Methods

The search was performed on PubMed and LILACS with the following terms: C9ORF72, MRI, SPECT, PET, ALS, FTD. No filters were added.

Results

Twenty articles were selected. Most studies found consistent involvement of frontotemporal regions in C9ORF72 carriers, including prefrontal cortex, and also cingulate, subcortical regions, especially the thalami, and posterior regions such as the parietal and occipital lobes. Functional connectivity was also explored and impaired sensorimotor connectivity in striatum and thalami was found in behavioral variant FTD C9ORF72 carriers. Some papers have reported an absence of significant abnormalities on brain imaging.

Conclusion

The inclusion of patients at different stages of the disease, differences in neuroimaging methods across studies, and distinct clinical phenotypes associated with C9ORF72 may account for the heterogeneity of results.

ALS Patient Stem Cells for Unveiling Disease Signatures of Motoneuron Susceptibility: Perspectives on the Deadly Mitochondria, ER Stress and Calcium Triad

Amyotrophic lateral sclerosis (ALS) is a largely sporadic progressive neurodegenerative disease affecting upper and lower motoneurons (MNs) whose specific etiology is incompletely understood. Mutations in superoxide dismutase-1 (SOD1), TAR DNA-binding protein 43 (TARDBP/TDP-43) and C9orf72, have been identified in subsets of familial and sporadic patients. Key associated molecular and neuropathological features include ubiquitinated TDP-43 inclusions, stress granules, aggregated dipeptide proteins from mutant C9orf72 transcripts, altered mitochondrial ultrastructure, dysregulated calcium homeostasis, oxidative and endoplasmic reticulum (ER) stress, and an unfolded protein response (UPR). Such impairments have been documented in ALS animal models; however, whether these mechanisms are initiating factors or later consequential events leading to MN vulnerability in ALS patients is debatable. Human induced pluripotent stem cells (iPSCs) are a valuable tool that could resolve this “chicken or egg” causality dilemma. Relevant systems for probing pathophysiologically affected cells from large numbers of ALS patients and discovering phenotypic disease signatures of early MN susceptibility are described. Performing unbiased ‘OMICS and high-throughput screening in relevant neural cells from a cohort of ALS patient iPSCs, and rescuing mitochondrial and ER stress impairments, can identify targeted therapeutics for increasing MN longevity in ALS.

P300-based brain-computer interface (BCI) event-related potentials (ERPs): People with amyotrophic lateral sclerosis (ALS) vs. age-matched controls

OBJECTIVE

Brain-computer interfaces (BCIs) aimed at restoring communication to people with severe neuromuscular disabilities often use event-related potentials (ERPs) in scalp-recorded EEG activity. Up to the present, most research and development in this area has been done in the laboratory with young healthy control subjects. In order to facilitate the development of BCI most useful to people with disabilities, the present study set out to: (1) determine whether people with amyotrophic lateral sclerosis (ALS) and healthy, age-matched volunteers (HVs) differ in the speed and accuracy of their ERP-based BCI use; (2) compare the ERP characteristics of these two groups; and (3) identify ERP-related factors that might enable improvement in BCI performance for people with disabilities.

METHODS

Sixteen EEG channels were recorded while people with ALS or healthy age-matched volunteers (HVs) used a P300-based BCI. The subjects with ALS had little or no remaining useful motor control (mean ALS Functional Rating Scale-Revised 9.4 (±9.5SD) (range 0-25)). Each subject attended to a target item as the items in a 6×6 visual matrix flashed. The BCI used a stepwise linear discriminant function (SWLDA) to determine the item the user wished to select (i.e., the target item). Offline analyses assessed the latencies, amplitudes, and locations of ERPs to the target and non-target items for people with ALS and age-matched control subjects.

RESULTS

BCI accuracy and communication rate did not differ significantly between ALS users and HVs. Although ERP morphology was similar for the two groups, their target ERPs differed significantly in the location and amplitude of the late positivity (P300), the amplitude of the early negativity (N200), and the latency of the late negativity (LN).

CONCLUSIONS

The differences in target ERP components between people with ALS and age-matched HVs are consistent with the growing recognition that ALS may affect cortical function. The development of BCIs for use by this population may begin with studies in HVs but also needs to include studies in people with ALS. Their differences in ERP components may affect the selection of electrode montages, and might also affect the selection of presentation parameters (e.g., matrix design, stimulation rate).

SIGNIFICANCE

P300-based BCI performance in people severely disabled by ALS is similar to that of age-matched control subjects. At the same time, their ERP components differ to some degree from those of controls. Attention to these differences could contribute to the development of BCIs useful to those with ALS and possibly to others with severe neuromuscular disabilities.

Brain morphologic changes in asymptomatic C9orf72 repeat expansion carriers

OBJECTIVE

To investigate possible effects of the C9orf72 repeat expansion before disease onset, we assessed brain morphology in asymptomatic carriers.

METHODS

Aiming to diminish the effects of genetic variation between subjects, apart from the C9orf72 repeat expansion, 16 carriers of the repeat expansion were compared with 23 noncarriers from the same large family with a history of amyotrophic lateral sclerosis (ALS). Cortical thickness, subcortical volumes, and white matter connectivity, as assessed from high-resolution T1-weighted and diffusion-weighted MRIs, were evaluated. For comparison, we included 14 C9orf72 carriers with ALS and 28 healthy, unrelated controls.

RESULTS

We found temporal, parietal, and occipital regions to be thinner (p < 0.05) and the left caudate and putamen to be smaller (p < 0.05) in asymptomatic carriers compared with noncarriers. Cortical thinning of the primary motor cortex and decreased connectivity of white matter pathways (global, corticospinal tract, and corpus callosum) were observed in patients with C9orf72-associated ALS, but not in asymptomatic carriers.

CONCLUSIONS

Asymptomatic C9orf72 carriers show cortical and subcortical differences compared with noncarriers from the same family, possibly effects of the C9orf72 repeat expansion on the brain. Of note, changes in the primary motor regions and motor-related tracts were found exclusively in patients with ALS, indicating that such motor changes may be a disease phenomenon.

Assisting persons with advanced amyotrophic lateral sclerosis in their leisure engagement and communication needs with a basic technology-aided program

BACKGROUND

Eye-tracking communication devices and brain-computer interfaces are the two resources available to help people with advanced amyotrophic lateral sclerosis (ALS) avoid isolation and passivity.

OBJECTIVE

This study was aimed at assessing a technology-aided program (i.e., a third possible resource) for five patients with advanced ALS who needed support for communication and leisure activities.

METHODS

The participants were exposed to baseline and intervention conditions. The technology-aided program, which was used during the intervention, (a) included the communication and leisure options that each participant considered important for him or her (e.g., music, videos, statements/requests, and text messaging) and (b) allowed the participant to access those options with minimal responses (e.g., finger movement or eyelid closure) monitored via microswitches.

RESULTS

The participants started leisure and communication engagement independently only during the intervention (i.e., when the program was used). The mean percentages of session time spent in those forms of engagement were between about 60 and 80. Preference checks and brief interviews indicated that participants and families liked the program.

CONCLUSIONS

The program might be viewed as an additional approach/resource for patients with advanced ALS.

Withdrawal of ventilation at the patient's request in MND: a retrospective exploration of the ethical and legal issues that have arisen for doctors in the UK

BACKGROUND

Ventilatory support has benefits including prolonging survival for respiratory failure in motor neurone disease (MND). At some point some patients may wish to stop the intervention. The National Institute of Health and Care Excellence (NICE) guidance recommends research is needed on ventilation withdrawal. There is little literature focusing on the issues doctors encounter when withdrawing ventilation at the request of a patient.

AIM

To identify and explore with doctors the ethical and legal issues that they had encountered in the withdrawal of ventilation at the request of a patient with MND.

METHOD

A retrospective thematic analysis of interviews of 24 doctors (including palliative care, respiratory, neurology and general practice) regarding their experiences with withdrawal of ventilation support from patients with MND.

RESULTS

Respondents found withdrawal of ventilation at the request of patients with MND to pose legal, ethical and moral challenges in five themes: ethical and legal rights to withdrawal from treatment; discussions with family; discussions with colleagues; experiences of legal advice; issues contributing to ethical complexity. Though clear about the legality of withdrawal of treatment in theory, the practice led to ethical and moral uncertainty and mixed feelings. Many respondents had experienced negative reactions from other healthcare professionals when these colleagues were unclear of the distinction between palliation of symptoms, withdrawal of treatment and assisted death.

CONCLUSIONS

Legal, ethical and practical guidance is needed for professionals who support a patient with MND who wishes to withdraw from ventilation. Open discussion of the ethical challenges is needed as well as education and support for professionals.

Eye-tracking in amyotrophic lateral sclerosis: A longitudinal study of saccadic and cognitive tasks

A relative preservation of eye movements is notable in ALS, but saccadic functions have not been studied longitudinally. ALS overlaps with FTD, typically involving executive dysfunction, and eye-tracking offers additional potential for the assessment of extramotor pathology where writing and speaking are both impaired. Eye-tracking measures (including anti-saccade, trail-making and visual search tasks) were assessed at six-monthly intervals for up to two years in a group of ALS (n = 61) and primary lateral sclerosis (n = 7) patients, compared to healthy age-matched controls (n = 39) assessed on a single occasion. Task performance was explored speculatively in relation to resting-state functional MRI (R-FMRI) network connectivity. Results showed that ALS patients were impaired on executive and visual search tasks despite normal basic saccadic function, and impairments in the PLS patients were unexpectedly often more severe. No significant progression was detected longitudinally in either group. No changes in R-FMRI network connectivity were identified in relation to patient performance. In conclusion, eye-tracking offers an objective means to assess extramotor cerebral involvement in ALS. The relative resistance of pure oculomotor function is confirmed, and higher-level executive impairments do not follow the same rate of decline as physical disability. PLS patients may have more cortical dysfunction than has been previously appreciated.

Motor and extra-motor gray matter atrophy in amyotrophic lateral sclerosis: quantitative meta-analyses of voxel-based morphometry studies

Considerable evidence from previous voxel-based morphometry studies indicates widespread but heterogeneous gray matter (GM) deficits in amyotrophic lateral sclerosis (ALS). Here, we aimed to investigate the concurrence across voxel-based morphometry studies to help clarify the spatial pattern of GM abnormalities that underlie this condition. Comprehensive meta-analyses to assess regional GM anomalies in ALS were conducted with the Anisotropic Effect Size version of Signed Differential Mapping software package. Twenty studies, which reported 22 comparisons and were composed of 454 ALS patients and 426 healthy controls, were included in the meta-analyses. Regional GM atrophy in ALS was consistently found in the frontal, temporal, and somatosensory areas. Meta-regression demonstrated that the disease duration, disease severity, and age were significantly related to GM deficits in ALS patients. The present meta-analysis provides convergent evidence that ALS is a multisystem degenerative disorder that is accompanied by a unique and widespread pattern of robust cortical GM atrophy. Future studies should investigate whether this atrophy pattern is a diagnostic and prognostic marker.

TDP-43 proteinopathies: pathological identification of brain regions differentiating clinical phenotypes

The pathological sequestration of TAR DNA-binding protein 43 (TDP-43, encoded by TARDBP) into cytoplasmic pathological inclusions characterizes the distinct clinical syndromes of amyotrophic lateral sclerosis and behavioural variant frontotemporal dementia, while also co-occurring in a proportion of patients with Alzheimer's disease, suggesting that the regional concentration of TDP-43 pathology has most relevance to specific clinical phenotypes. This has been reflected in the three different pathological staging schemes for TDP-43 pathology in these different clinical syndromes, with none of these staging schemes including a preclinical phase similar to that which has proven beneficial in other neurodegenerative diseases. To apply each of these three staging schemes for TDP-43 pathology, the clinical phenotype must be known undermining the potential predictive value of the pathological examination. The present study set out to test whether a more unified approach could accurately predict clinical phenotypes based solely on the regional presence and severity of TDP-43 pathology. The selection of brain regions of interest was based on key regions routinely sampled for neuropathological assessment under current consensus criteria that have also been used in the three TDP-43 staging schemes. The severity of TDP-43 pathology in these regions of interest was assessed in four clinicopathological phenotypes: amyotrophic lateral sclerosis (n = 27, 47-78 years, 15 males), behavioural variant frontotemporal dementia (n = 15, 49-82 years, seven males), Alzheimer's disease (n = 26, 51-90 years, 11 males) and cognitively normal elderly individuals (n = 17, 80-103 years, nine males). Our results demonstrate that the presence of TDP-43 in the hypoglossal nucleus discriminates patients with amyotrophic lateral sclerosis with an accuracy of 98%. The severity of TDP-43 deposited in the anterior cingulate cortex identifies patients with behavioural variant frontotemporal dementia with an accuracy of 99%. This identification of regional pathology associated with distinct clinical phenotypes suggests key regions on which probabilistic pathological criteria, similar to those currently available for Alzheimer's disease and dementia with Lewy bodies, can be developed for TDP-43 proteinopathies. We propose and validate a simplified probabilistic statement that involves grading the presence of TDP-43 in the hypoglossal nucleus and the severity of TDP-43 in the anterior cingulate for the pathological identification of TDP-43 proteinopathy cases with clinical amyotrophic lateral sclerosis and behavioural variant frontotemporal dementia.

Impaired cognitive flexibility in amyotrophic lateral sclerosis

BACKGROUND AND OBJECTIVE

Up to half of patients with amyotrophic lateral sclerosis (ALS) may have cognitive difficulty, but most cognitive measures are confounded by a motor component. Studies relating impaired cognition in ALS to disease in gray matter and white matter are rare. Our objective was to assess executive function in patients with ALS using a simple, untimed measure with minimal motor demands, and to relate performance to structural disease.

METHODS

We gave the Visual-Verbal Test to 56 patients with ALS and 29 matched healthy controls. This brief, untimed measure of cognitive flexibility first assesses participants' ability to identify a feature shared by 3 of 4 simple geometric designs. The participants' cognitive flexibility is challenged when they are next asked to identify a different feature shared by another combination of 3 of the same 4 geometric designs. In a subset of 17 patients who underwent magnetic resonance imaging, regression analyses related test performance to gray matter atrophy and reduced white matter fractional anisotropy.

RESULTS

The patients with ALS showed significant impairment in cognitive flexibility (P<0.01), with 48.2% making an error on the test. Regression analyses related impaired cognitive flexibility to gray matter atrophy in inferior frontal and insular regions, and to reduced fractional anisotropy in white matter projections in the inferior fronto-occipital and uncinate fasciculi and corpus callosum.

CONCLUSIONS

Our patients with ALS had impaired cognitive flexibility on an untimed measure with minimal motor demands, a finding related in part to a large-scale frontal network that is degraded in ALS.

Propagation of pathology through brain networks in neurodegenerative diseases: from molecules to clinical phenotypes

The cellular mechanisms underlying the stereotypical progression of pathology in neurodegenerative diseases are incompletely understood, but increasing evidence indicates that misfolded protein aggregates can spread by a self-perpetuating neuron-to-neuron transmission. Novel neuroimaging techniques can help elucidating how these disorders spread across brain networks. Recent knowledge from structural and functional connectivity studies suggests that the relation between neurodegenerative diseases and distinct brain networks is likely to be a strict consequence of diffuse network dynamics. Diffusion tensor magnetic resonance imaging also showed that measurement of white matter tract involvement can be a valid surrogate to assess the in vivo spreading of pathological proteins in these conditions. This review will introduce briefly the main molecular and pathological substrates of the most frequent neurodegenerative diseases and provide a comprehensive overview of neuroimaging findings that support the "network-based neurodegeneration" hypothesis in these disorders. Characterizing network breakdown in neurodegenerative diseases will help anticipate and perhaps prevent the devastating impact of these conditions.

A systematic review of the validity and reliability of apathy scales in neurodegenerative conditions

BACKGROUND

There are several scales used to detect apathy in disease populations. Since apathy is a prevalent symptom in many neurodegenerative diseases, this is an especially important context in which to identify and compare scales.

AIMS

To provide an overview of apathy scales validated in generic and specific neurodegenerative disease populations, compare validation studies' methodological quality and the psychometric properties of the validated apathy scales.

METHODS

A systematic review of literature was conducted of articles published between 1980 and 2013. The final articles selected for review were rated on methodological quality and the psychometric properties of the scales used were interpreted.

RESULTS

Sixteen articles validating apathy scales were included in the review, five in a generic neurodegenerative sample and eleven in specific neurodegenerative samples. The methodological quality of specific studies varied from poor to excellent. The highest quality, which had psychometrically favorable scales, were the dementia apathy interview and rating (DAIR) and the apathy evaluation scale-clinical version (AES-C) in Alzheimer's disease and the Lille apathy rating scale (LARS) in Parkinson's disease. Generic neurodegenerative disease validation studies were of average methodological quality and yielded inconsistent psychometric properties.

CONCLUSIONS

Several instruments can be recommended for use in some specific neurodegenerative diseases. Other instruments should either be validated or developed to assess apathy in more generic populations.

Validation of the Edinburgh Cognitive and Behavioural Amyotrophic Lateral Sclerosis Screen (ECAS): A cognitive tool for motor disorders

Our objective was to assess the validity of the Edinburgh Cognitive and Behaviour ALS Screen (ECAS), a multi-domain screen designed to detect cognitive deficits in patients with motor disorders. Forty ALS patients (without pre-diagnosed dementia) and 40, age-, gender- and education-matched healthy controls were recruited. All participants underwent extensive neuropsychological assessment and the ECAS. Performance at neuropsychological assessment across five domains (fluency, executive function, language, memory and visuospatial function) was compared to the ECAS ALS-Specific (fluency, executive functions and social cognition, language), ALS Non-specific (memory, visuospatial functions), and Total scores. Data from the healthy controls produced population-based abnormality cut-offs: composite score performance ≤ 2 SD in any domain classified impairment at neuropsychological assessment. Thirty-three percent of patients were impaired, most commonly in a single domain (executive or language dysfunction). Receiver Operator Curve (ROC) analyses using ECAS Total scores and ALS-Specific scores revealed 85% sensitivity and 85% specificity in the detection of cognitive impairment characteristic of ALS (fluency, executive function, language). A five-point borderline range produced optimal values (ALS-Specific Score 77-82, and ECAS-Total Score 105-110). In conclusion, validation against gold standard extensive neuropsychology demonstrated that the ECAS is a screening tool with high sensitivity and specificity to impairment characteristic of ALS.

Coordinated care affects hospitalization and prognosis in amyotrophic lateral sclerosis: a cohort study

Background

To determine whether an integrated approach to coordination of care influences hospitalization and clinical outcomes in a chronic neurological disease, amyotrophic lateral sclerosis.

Methods

We followed up 2452 patients with probable or definite amyotrophic lateral sclerosis from 2000 to 2012. Two cohorts were compared before and after the creation of a community care network for this disease in Ile de France in 2006. During these two periods, the medical and paramedical care teams and formal standards of care were identical; the only difference was the coordination by the network. To investigate hospital and emergency department use, we used number of patients, number of stays, and number of days. For clinical outcomes, we used slopes of functional deterioration, and Kaplan–Meier and Cox models for survival.

Results

All hospitalization variables decreased after the creation of the network, which was not explained by admissions elsewhere. The slope of functional deterioration was significantly different before (1.03 ± 1.57 points/month) and after (0.79 ± 0.80 points/month; p = 0.002) creation of the network. Patients included in the network had a median survival time of 13.2 months more (log rank test; p < 0.001). In the Cox model, the network intervention was associated with a 45% decrease in relative risk of death during the period of the study (p < 0.001).

Conclusions

Network care was associated with fewer hospital admissions, reduced functional deterioration and later mortality in ALS. These results suggest that proactive coordination between carers in chronic and complex diseases could have a positive impact on hospitalization and the clinical course of the disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-015-0810-7) contains supplementary material, which is available to authorized users.

Supporting communication for patients with neurodegenerative disease

BACKGROUND

Communication supports, referred to as augmentative and alternative communication (AAC), are an integral part of medical speech-language pathology practice, yet many providers remain unfamiliar with assessment and intervention principles. For patients with complex communication impairments secondary to neurodegenerative disease, AAC services differ depending on whether their condition primarily affects speech and motor skills (ALS), language (primary progressive aphasia) or cognition (Alzheimer's disease). This review discusses symptom management for these three conditions, identifying behavioral strategies, low- and high-tech solutions for implementation during the natural course of disease. These AAC principles apply to all neurodegenerative diseases in which common symptoms appear.

OBJECTIVES

To present AAC interventions for patients with neurodegenerative diseases affecting speech, motor, language and cognitive domains. Three themes emerge: (1) timing of intervention: early referral, regular re-evaluations and continual treatment are essential; (2) communication partners must be included from the onset to establish AAC acceptance and use; and (3) strategies will change over time and use multiple modalities to capitalize on patients' strengths.

CONCLUSIONS

AAC should be standard practice for adults with neurodegenerative disease. Patients can maintain effective, functional communication with AAC supports. Individualized communication systems can be implemented ensuring patients remain active participants in daily activities.

Neural substrate of cognitive theory of mind impairment in amyotrophic lateral sclerosis

We now know that amyotrophic lateral sclerosis (ALS) is not restricted to the motor system. Indeed, a large proportion of patients with ALS exhibit cognitive impairment, especially executive dysfunction or language impairment. Although researchers have recently turned their attention to theory of mind (ToM) in ALS, only five studies have been performed so far, and they reported somewhat contradictory results. Moreover, the neural basis of the potential ToM deficit in ALS remains largely unknown. The present study was therefore designed to clarify whether a cognitive ToM deficit is indeed associated with ALS, specify the putative link between cognitive ToM deficits and executive dysfunction in ALS, and identify the dysfunctional brain regions responsible for any social cognition deficits. We investigated cognitive ToM and executive functions in a group of 23 patients with ALS and matched healthy controls, using an original false-belief task and a specially designed battery of executive tasks. We also performed an (18)F-fluorodeoxyglucose positron emission tomography examination. Results confirmed the presence of cognitive ToM deficits in patients compared with controls, and revealed significant correlations between ToM and executive functions, although the cognitive ToM deficit persisted when a composite executive function score was entered as a covariate. Using statistical parametric mapping, we calculated positive correlations between tracer uptake and false-belief scores on a voxel-by-voxel basis in the patient sample. Results showed that the cognitive ToM deficit correlated with the dorsomedial and dorsolateral prefrontal cortices, as well as the supplementary motor area. Our findings provide compelling clinical and imaging evidence for the presence of a genuine cognitive ToM deficit in patients with ALS.

Microstructural white matter changes underlying cognitive and behavioural impairment in ALS--an in vivo study using DTI

Background

A relevant fraction of patients with amyotrophic lateral sclerosis (ALS) exhibit a fronto-temporal pattern of cognitive and behavioural disturbances with pronounced deficits in executive functioning and cognitive control of behaviour. Structural imaging shows a decline in fronto-temporal brain areas, but most brain imaging studies did not evaluate cognitive status. We investigated microstructural white matter changes underlying cognitive impairment using diffusion tensor imaging (DTI) in a large cohort of ALS patients.

Methods

We assessed 72 non-demented ALS patients and 65 matched healthy control subjects using a comprehensive neuropsychological test battery and DTI. We compared DTI measures of fiber tract integrity using tract-based spatial statistics among ALS patients with and without cognitive impairment and healthy controls. Neuropsychological performance and behavioural measures were correlated with DTI measures.

Results

Patients without cognitive impairment demonstrated white matter changes predominantly in motor tracts, including the corticospinal tract and the body of corpus callosum. Those with impairments (ca. 30%) additionally presented significant white matter alterations in extra-motor regions, particularly the frontal lobe. Executive and memory performance and behavioural measures were correlated with fiber tract integrity in large association tracts.

Conclusion

In non-demented cognitively impaired ALS patients, white matter changes measured by DTI are related to disturbances of executive and memory functions, including prefrontal and temporal regions. In a group comparison, DTI is able to observe differences between cognitively unimpaired and impaired ALS patients.

Deficits in sentence expression in amyotrophic lateral sclerosis

Quantitative examinations of speech production in amyotrophic lateral sclerosis (ALS) are rare. To identify language features minimally confounded by a motor disorder, we investigated linguistic and motor sources of impaired sentence expression in ALS, and we related deficits to gray matter (GM) and white matter (WM) MRI abnormalities. We analyzed a semi-structured speech sample in 26 ALS patients and 19 healthy seniors for motor- and language-related deficits. Regression analyses related grammaticality to GM atrophy and reduced WM fractional anisotropy (FA). Results demonstrated that ALS patients were impaired relative to controls on quantity of speech, speech rate, speech articulation errors, and grammaticality. Speech rate and articulation errors were related to the patients' motor impairment, while grammatical difficulty was independent of motor difficulty. This was confirmed in subgroups without dysarthria and without executive deficits. Regressions related grammatical expression to GM atrophy in left inferior frontal and anterior temporal regions and to reduced FA in superior longitudinal and inferior frontal-occipital fasciculi. In conclusion, patients with ALS exhibit multifactorial deficits in sentence expression. They demonstrate a deficit in grammatical expression that is independent of their motor disorder. Impaired grammatical expression is related to disease in a network of brain regions associated with syntactic processing.

Alterations in microRNA-124 and AMPA receptors contribute to social behavioral deficits in frontotemporal dementia

Neurodegenerative diseases, such as frontotemporal dementia (FTD), are often associated with behavioral deficits, but the underlying anatomical and molecular causes remain poorly understood. Here we show that forebrain-specific expression of FTD-associated mutant CHMP2B in mice causes several age-dependent neurodegenerative phenotypes, including social behavioral impairments. The social deficits were accompanied by a change in AMPA receptor (AMPAR) composition, leading to an imbalance between Ca(2+)-permeable and Ca(2+)-impermeable AMPARs. Expression of most AMPAR subunits was regulated by the brain-enriched microRNA miR-124, whose abundance was markedly decreased in the superficial layers of the cerebral cortex of mice expressing the mutant CHMP2B. We found similar changes in miR-124 and AMPAR levels in the frontal cortex and induced pluripotent stem cell-derived neurons from subjects with behavioral variant FTD. Moreover, ectopic miR-124 expression in the medial prefrontal cortex of mutant mice decreased AMPAR levels and partially rescued behavioral deficits. Knockdown of the AMPAR subunit Gria2 also alleviated social impairments. Our results identify a previously undescribed mechanism involving miR-124 and AMPARs in regulating social behavior in FTD and suggest a potential therapeutic avenue.

Developing a new apathy measurement scale: Dimensional Apathy Scale

Apathy is both a symptom and syndrome prevalent in neurodegenerative disease, including motor system disorders, that affects motivation to display goal directed functions. Levy and Dubois (2006) suggested three apathetic subtypes, Cognitive, Emotional-affective and Auto-activation, all with discrete neural correlates and functional impairments. The aim of this study was to create a new apathy measure; the Dimensional Apathy Scale (DAS), which assesses apathetic subtypes and is suitable for use in patient groups with motor dysfunction. 311 healthy participants (mean=37.4, S.D.=15.0) completed a 45-item questionnaire. Horn's parallel analysis of principal factors and Exploratory Factor Analysis resulted in 4 factors (Executive, Emotional, Cognitive Initiation and Behavioural Initiation) that account for 28.9% of the total variance. Twenty four items were subsequently extracted to form 3 subscales--Executive, Emotional and Behavioural/Cognitive Initiation. The subscale items show good internal consistency reliability. A weak to moderate relationship was found with depression using Becks Depression Inventory II. The DAS is a well-constructed method for assessing multidimensional apathy suitable for application to investigate this syndrome in different disease pathologies.

MicroRNAs as potential circulating biomarkers for amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a condition primarily characterized by the selective loss of upper and lower motor neurons. Motor neuron loss gives rise to muscle tissue malfunctions, including weakness, spasticity, atrophy, and ultimately paralysis, with death typically due to respiratory failure within 2 to 5 years of symptoms' onset. The mean delay in time from presentation to diagnosis remains at over 1 year. Biomarkers are urgently needed to facilitate ALS diagnosis and prognosis as well as to act as indicators of therapeutic response in clinical trials. MicroRNAs (miRNAs) are small molecules that can influence posttranscriptional gene expression of a variety of transcript targets. Interestingly, miRNAs can be released into the circulation by pathologically affected tissues. This review presents therapeutic and diagnostic challenges associated with ALS, highlights the potential role of miRNAs in ALS, and discusses the diagnostic potential of these molecules in identifying ALS-specific miRNAs or in distinguishing between the various genotypic and phenotypic forms of ALS.

Prognostic factors for the course of functional status of patients with ALS: a systematic review

The progressive course of amyotrophic lateral sclerosis (ALS) results in an ever-changing spectrum of the care needs of patients with ALS. Knowledge of prognostic factors for the functional course of ALS may enhance clinical prediction and improve the timing of appropriate interventions. Our objective was to systematically review the evidence regarding prognostic factors for the rate of functional decline of patients with ALS, assessed with versions of the ALS Functional Rating Scale (ALSFRS). Two reviewers independently assessed the methodological quality of the thirteen included studies using the Quality in Prognosis Studies (QUIPS) tool. The overall quality of evidence for each prognostic factor was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, considering risk of bias, imprecision, inconsistency, indirectness, and publication bias. The quality of evidence for the prognostic value of age at onset, site of onset, time from symptom onset to diagnosis, and ALSFRS-Revised baseline score was low, mainly due to the limited data and inconsistency of results in the small number of studies included. The prognostic value of initial rate of disease progression, age at diagnosis, forced vital capacity, frontotemporal dementia, body mass index, and comorbidity remains unclear. We conclude that the current evidence on prognostic factors for functional decline in ALS is insufficient to allow the development of a prediction tool that can support clinical decisions. Given the limited data, future prognostic studies may need to focus on factors that have a predictive value for a decline in ALSFRS(-R) domain scores, preferably based on internationally collected and shared data.

Effect of a short-term psychological intervention on the anxiety and depression of amyotrophic lateral sclerosis patients

This study evaluated the effectiveness of a psychological intervention in amyotrophic lateral sclerosis patients, consisting of four semi-structured sessions of cognitive behavioural therapy combined with counselling techniques. An intervention group and a control group were established. The Hospital Anxiety and Depression Scale was used to assess levels of anxiety and depression. In total, fifty-four patients took part. Prior to the intervention, the intervention group displayed rates of 63.3 and 36.7 per cent for anxiety and depression, respectively, falling to 16.7 and 10.0 per cent afterwards. The psychological intervention demonstrated potential for the reduction of levels of anxiety and depression in amyotrophic lateral sclerosis patients.

ALS-Plus syndrome: non-pyramidal features in a large ALS cohort

OBJECTIVE

Autopsy studies show widespread pathology in amyotrophic lateral sclerosis (ALS), but clinical surveys of multisystem disease in ALS are rare. We investigated ALS-Plus syndrome, an understudied group of patients with clinical features extending beyond pyramidal and neuromuscular systems with or without cognitive/behavioral deficits.

METHODS

In a large, consecutively-ascertained cohort of 550 patients with ALS, we documented atypical clinical manifestations. Genetic screening for C9orf72 hexanucleotide expansions was performed in 343 patients, and SOD1, TARDBP, and VCP were tested in the subgroup of patients with a family history of ALS. Gray matter and white matter imaging was available in a subgroup of 30 patients.

RESULTS

Seventy-five (13.6%) patients were identified with ALS-Plus syndrome. We found disorders of ocular motility, cerebellar, extrapyramidal and autonomic functioning. Relative to those without ALS-Plus, cognitive impairment (8.0% vs 2.9%, p=0.029), bulbar-onset (49.3% vs 23.2%, p<0.001), and pathogenic mutations (20.0% vs 8.4%, p=0.015) were more than twice as common in ALS-Plus. Survival was significantly shorter in ALS-Plus (29.66 months vs 42.50 months, p=0.02), regardless of bulbar-onset or mutation status. Imaging revealed significantly greater cerebellar and cerebral disease in ALS-Plus compared to those without ALS-Plus.

CONCLUSIONS

ALS-Plus syndrome is not uncommon, and the presence of these atypical features is consistent with neuropathological observations that ALS is a multisystem disorder. ALS-Plus syndrome is associated with increased risk for poor survival and the presence of a pathogenic mutation.

The Edinburgh Cognitive and Behavioural Amyotrophic Lateral Sclerosis Screen: a cross-sectional comparison of established screening tools in a German-Swiss population

The Edinburgh Cognitive and Behavioural ALS Screen (ECAS) has recently been developed as a fast and easy cognitive screening tool specifically designed for patients with motor impairments in routine clinical use. The German/Swiss-German version of the ECAS was validated in a German-Swiss consortium. One hundred and thirty-six non-demented ALS patients and 160 healthy controls were included in the study. In addition, the Frontal Assessment Battery (FAB), Montreal Cognitive Assessment (MoCA) and Consortium to Establish a Registry for Alzheimer's Disease plus Scale (CERAD plus) were administered to subgroups of patients. Results showed that administration of ECAS was fast (mean 24 min). Similar to the population in the UK version, ALS patients performed significantly worse in the ALS-specific functions (p < 0.001), specifically in the domain of language (p < 0.001), verbal fluency (p = 0.005) and executive functions (p = 0.02), but not for the non-ALS-specific functions. Carers reported behavioural abnormalities in about 30% and psychotic symptoms in 6% of the patients. Compared to ECAS, FAB, MoCA and CERAD were more generic and performance was not adjusted to motor speed. We conclude that the German/Swiss-German version of the ECAS is a fast and easy to administer cognitive screening instrument sensitive for ALS-specific dysfunctions and behaviour change.

Psychological as well as illness factors influence acceptance of non-invasive ventilation (NIV) and gastrostomy in amyotrophic lateral sclerosis (ALS): a prospective population study

Our objective was to identify factors associated with acceptance of non-invasive ventilation (NIV) and gastrostomy in an exploratory population-based study. Seventy-eight people with ALS at least six months post-diagnosis, and 50 caregivers, were recruited from the South-East ALS Register. Baseline physical, cognitive and psychological measures were obtained. Three-monthly follow-ups monitored whether patients had accepted or refused NIV or gastrostomy. Following an intervention decision, post-decision interviews repeated baseline measures and included further intervention-specific questionnaires. Results showed that 32 people with ALS made at least one intervention decision and of these 10 decided about both NIV and gastrostomy. While illness factors predicted those needing to make an intervention decision, cognitive and education status, and level of executive dysfunction were associated with decision-making and acceptance or refusal of interventions. Patients' understanding of their illness, their early approach to considering interventions and carer-related factors were also associated with treatment decisions. In conclusion, our findings highlight the complexity of decision-making and provide a platform for designing further studies. Cognitive and psychosocial factors may assume a greater role in palliative care decisions for people with ALS than has been explicitly recognized. Future work must clarify how to ensure patients are not inadvertently being denied suitable interventions.

HDL and cognition in neurodegenerative disorders

High-density lipoproteins (HDLs) are a heterogeneous group of lipoproteins composed of various lipids and proteins. HDL is formed both in the systemic circulation and in the brain. In addition to being a crucial player in the reverse cholesterol transport pathway, HDL possesses a wide range of other functions including anti-oxidation, anti-inflammation, pro-endothelial function, anti-thrombosis, and modulation of immune function. It has been firmly established that high plasma levels of HDL protect against cardiovascular disease. Accumulating evidence indicates that the beneficial role of HDL extends to many other systems including the central nervous system. Cognition is a complex brain function that includes all aspects of perception, thought, and memory. Cognitive function often declines during aging and this decline manifests as cognitive impairment/dementia in age-related and progressive neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. A growing concern is that no effective therapy is currently available to prevent or treat these devastating diseases. Emerging evidence suggests that HDL may play a pivotal role in preserving cognitive function under normal and pathological conditions. This review attempts to summarize recent genetic, clinical and experimental evidence for the impact of HDL on cognition in aging and in neurodegenerative disorders as well as the potential of HDL-enhancing approaches to improve cognitive function.

The hubs of the human connectome are generally implicated in the anatomy of brain disorders

Brain networks or 'connectomes' include a minority of highly connected hub nodes that are functionally valuable, because their topological centrality supports integrative processing and adaptive behaviours. Recent studies also suggest that hubs have higher metabolic demands and longer-distance connections than other brain regions, and therefore could be considered biologically costly. Assuming that hubs thus normally combine both high topological value and high biological cost, we predicted that pathological brain lesions would be concentrated in hub regions. To test this general hypothesis, we first identified the hubs of brain anatomical networks estimated from diffusion tensor imaging data on healthy volunteers (n = 56), and showed that computational attacks targeted on hubs disproportionally degraded the efficiency of brain networks compared to random attacks. We then prepared grey matter lesion maps, based on meta-analyses of published magnetic resonance imaging data on more than 20 000 subjects and 26 different brain disorders. Magnetic resonance imaging lesions that were common across all brain disorders were more likely to be located in hubs of the normal brain connectome (P < 10(-4), permutation test). Specifically, nine brain disorders had lesions that were significantly more likely to be located in hubs (P < 0.05, permutation test), including schizophrenia and Alzheimer's disease. Both these disorders had significantly hub-concentrated lesion distributions, although (almost completely) distinct subsets of cortical hubs were lesioned in each disorder: temporal lobe hubs specifically were associated with higher lesion probability in Alzheimer's disease, whereas in schizophrenia lesions were concentrated in both frontal and temporal cortical hubs. These results linking pathological lesions to the topological centrality of nodes in the normal diffusion tensor imaging connectome were generally replicated when hubs were defined instead by the meta-analysis of more than 1500 task-related functional neuroimaging studies of healthy volunteers to create a normative functional co-activation network. We conclude that the high cost/high value hubs of human brain networks are more likely to be anatomically abnormal than non-hubs in many (if not all) brain disorders.

Longitudinal course of cortical thickness decline in amyotrophic lateral sclerosis

To determine longitudinal rates of cortical atrophy in classical Amyotrophic lateral sclerosis (ALS) and ALS variants. Rates of cortical thinning were determined between 2 scans, 3-15 months apart, in 77 ALS patients: 51 classical, 12 upper motor neuron (UMN), and 14 lower motor neuron (LMN) ALS variants. Cortical thickness at the first assessment was compared with 60 healthy controls matched by age and gender. Atrophy rates were compared between patient sub-groups and correlated with disease duration, progression, and severity. Using a cross-sectional analysis, we found a significant difference in cortical thickness between ALS patients and controls in the motor and extra-motor areas (left medial orbito frontal gyrus, left inferior parietal gyrus, bilateral insular cortex, right fusiform gyrus, bilateral precuneus). Using a longitudinal analysis, we found a significant decline of cortical thickness in frontal, temporal, and parietal regions over the course of the study in ALS patients. Effects were independent of the clinical subtype, with exception of the precentral gyrus (p < 0.001). The LMN ALS variants demonstrated the highest rates of cortical thinning in the precentral gyrus, the UMN-dominant subjects exhibited intermediate rates of atrophy, and the classical ALS patients exhibited no such change. Atrophy of the precentral gyrus in classical ALS indicates a floor effect at the first assessment, resulting in a lack of further atrophy over time. Structural loss of the precentral gyrus appears to be an early sign of classical ALS. Over time, patterns of cortical thinning in extra-motor areas can be identified in ALS, regardless of the phenotype.

Memory deficits in amyotrophic lateral sclerosis are not exclusively caused by executive dysfunction: a comparative neuropsychological study of amnestic mild cognitive impairment

Background

Recent work suggests that ALS and frontotemporal dementia can occur together and share at least in part the same underlying pathophysiology. However, it is unclear at present whether memory deficits in ALS stem from a temporal lobe dysfunction, or are rather driven by frontal executive dysfunction. In this study we sought to investigate the nature of memory deficits by analyzing the neuropsychological performance of 40 ALS patients in comparison to 39 amnestic mild cognitive impairment (aMCI) patients and 40 healthy controls (HC). The neuropsychological battery tested for impairment in executive functions, as well as memory and visuo-spatial skills, the results of which were compared across study groups. In addition, we calculated composite scores for memory (learning, recall, recognition) and executive functions (verbal fluency, cognitive flexibility, working memory). We hypothesized that the nature of memory impairment in ALS will be different from those exhibited by aMCI patients.

Results

Patient groups exhibited significant differences in their type of memory deficit, with the ALS group showing impairment only in recognition, whereas aMCI patients showed short and delayed recall performance deficits as well as reduced short-term capacity. Regression analysis revealed a significant impact of executive function on memory performance exclusively for the ALS group, accounting for one fifth of their memory performance. Interestingly, merging all sub scores into a single memory and an executive function score obscured these differences.

Conclusion

The presented results indicate that the interpretation of neuropsychological scores needs to take the distinct cognitive profiles in ALS and aMCI into consideration. Importantly, the observed memory deficits in ALS were distinctly different from those observed in aMCI and can be explained only to some extent in the context of comorbid (coexisting) executive dysfunction. These findings highlight the qualitative differences in temporal lobe dysfunction between ALS and aMCI patients, and support temporal lobe dysfunction as a mechanism underlying the distinct cognitive impairments observed in ALS.

Action verb comprehension in amyotrophic lateral sclerosis and Parkinson's disease

Patients with amyotrophic lateral sclerosis (ALS) have a motor disorder and cognitive difficulties, including difficulty with action verbs. However, the basis for the action verb impairment is unknown. Thirty-six participants with ALS and 22 with Parkinson's disease (PD) were assessed on a simple, two-alternative forced-choice associativity judgment task, where performance was untimed and did not depend on motor functioning. We probed 120 frequency-matched action verbs, cognition verbs, concrete nouns and abstract nouns. Performance was related to T1 MRI imaging of gray matter atrophy. Patients with ALS were significantly impaired relative to healthy senior control participants only for action verbs. Patients with PD did not differ from controls for all word categories. Regression analyses related action verb performance in ALS to motor-associated cortices, but action verb judgments in PD were not related to cortical atrophy. These findings are consistent with the hypothesis that action verb difficulty in ALS is related in part to the degradation of action-related conceptual knowledge represented in motor-associated cortex.