Cognitive correlates in amyotrophic lateral sclerosis: a population-based study in Italy

Update on recent advances in amyotrophic lateral sclerosis

In the last few years, our understanding of disease molecular mechanisms underpinning ALS has advanced greatly, allowing the first steps in translating into clinical practice novel research findings, including gene therapy approaches. Similarly, the recent advent of assistive technologies has greatly improved the possibility of a more personalized approach to supportive and symptomatic care, in the context of an increasingly complex multidisciplinary line of actions, which remains the cornerstone of ALS management. Against this rapidly growing background, here we provide an comprehensive update on the most recent studies that have contributed towards our understanding of ALS pathogenesis, the latest results from clinical trials as well as the future directions for improving the clinical management of ALS patients.

Cognitive function in amyotrophic lateral sclerosis: a cross-sectional and prospective pragmatic clinical study with review of the literature

BACKGROUND

Amyotrophic lateral sclerosis (ALS) can present with either bulbar or spinal symptoms, and in some cases, both types of symptoms may be present. In addition, cognitive impairment has been observed in ALS. The study aimed to evaluate the frontal and general cognitive performance in ALS not only cross-sectionally but also longitudinally.

METHODS AND MATERIALS

The Frontal Assessment Battery (FAB) and the Montreal Cognitive Assessment (MoCA) were employed to assess cognitive function in 52 adults with ALS and 52 cognitively healthy individuals. The statistical analyses encompassed the Pearson Chi square test, the Skillings-Mack test, the Spearman's rank correlation coefficient, and the Proportional Odds Logistic Regression Model (POLR).

RESULTS

Cross-sectionally, lower cognitive performance was associated with ALS diagnosis, older age, and motor functional decline. The cognitive impairment of individuals with bulbar and spinal-bulbar symptoms showed faster deterioration compared to those with spinal symptoms. The spinal subgroup consistently performed worst in delayed recall and attention, while the spinal-bulbar and bulbar subgroups exhibited inferior scores in delayed recall, attention, visuospatial skills, orientation, and verbal fluency.

CONCLUSION

The incorporation of cognitive screening in the diagnostic workup of ALS may be beneficial, as early detection can enhance symptom management and improve the quality of life for both individuals with ALS and their care partners.

C9orf72 repeat expansions modify risk for secondary motor and cognitive-behavioral symptoms in behavioral-variant frontotemporal degeneration and amyotrophic lateral sclerosis

In behavioral-variant frontotemporal degeneration (bvFTD) and amyotrophic lateral sclerosis (ALS), the presence of secondary motor or cognitive-behavioral symptoms, respectively, is associated with shorter survival. However, factors influencing the risk and hazard of secondary symptom development remain largely unexplored. We performed a retrospective evaluation of the entire disease course of individuals with amyotrophic lateral sclerosis (n=172) and behavioral-variant frontotemporal degeneration (n=69). Only individuals who had neuropathological confirmation of a TDP-43 proteinopathy at autopsy or had a C9orf72 repeat expansion were included for analysis. We examined the odds and hazard of secondary symptom development and assessed whether they were modified by the presence of a C9orf72 repeat expansion or initial clinical syndrome. Binary logistic regression and Cox proportional hazard analyses revealed increased odds (OR=4.25 [1.97-9.14]; p<0.001) and an increased hazard (HR= 4.77 [2.33-9.79], p<0.001) for developing secondary symptoms in C9orf72 expansion carriers compared to noncarriers. Initial clinical syndrome (bvFTD or ALS), age at symptom onset, and sex were not associated with development of secondary motor or cognitive-behavioral symptoms. These findings highlight the need for clinician vigilance to detect the onset of secondary motor symptoms and cognitive-behavioral in patients carrying a C9orf72 repeat expansion, regardless of initial clinical syndrome, and may warrant dual referrals between cognitive and neuromuscular clinics in these cases.

Evaluating emerging drugs in phase II & III for the treatment of amyotrophic lateral sclerosis

INTRODUCTION

Amyotrophic Lateral Sclerosis is a rapidly progressive motor neuron disorder causing severe disability and premature death. Owing to the advances in uncovering ALS pathophysiology, efficient clinical trial design and research advocacy program, several disease-modifying drugs have been approved for treating ALS. Despite this progress, ALS remains a rapidly disabling and life shortening condition. There is a critical need for more effective therapies.

AREAS COVERED

Here, we reviewed the emerging ALS therapeutics undergoing phase II & III clinical trials. To identify the investigational drugs, we searched ALS and phase II/III trials that are active and recruiting or not yet recruiting on clinicaltrials.gov and Pharmaprojects database.

EXPERT OPINION

The current pipeline is larger and more diverse than ever, with drugs targeting potential genetic and retroviral causes of ALS and drugs targeting a wide array of downstream pathways, including RNA metabolism, protein aggregation, integrated stress response and neuroinflammation.We remain most excited about those that target direct causes of ALS, e.g. antisense oligonucleotides targeting causative genes. Drugs that eliminate abnormal protein aggregates are also up-and-coming. Eventually, because of the heterogeneity of ALS pathophysiology, biomarkers that determine which biological events are most important for an individual ALS patient are needed.

Cognitive and Behavioral Features of Patients With Amyotrophic Lateral Sclerosis Who Are Carriers of the TARDBP Pathogenic Variant

BACKGROUND AND OBJECTIVES

TARDBP patients are considered particularly prone to cognitive involvement, but no systematic studies of cognitive impairment in TARDBP patients are available. The aim of this article was to depict in depth the cognitive-behavioral characteristics of a cohort of patients with amyotrophic lateral sclerosis (ALS) carrying TARDBP pathogenetic variants followed by an ALS referral center.

METHODS

We enrolled all patients with ALS seen at the Turin ALS expert center in the 2009-2021 period who underwent extensive genetic testing and a neuropsychological battery encompassing executive function, verbal memory, language, visual memory, visuoconstructive abilities, attention/working memory, psychomotor speed, nonverbal intelligence, cognitive flexibility, social cognition, and behavior. Tests were compared with the Mann-Whitney U test on age-corrected, sex-corrected, and education-corrected scores. Cognition was classified as normal (ALS-CN); isolated cognitive impairment (ALSci), that is, evidence of executive and/or language dysfunction; isolated behavioral impairment (ALSbi), that is, identification of apathy; cognitive and behavioral impairment (ALScbi), that is, evidence meeting the criteria for both ALSci and ALSbi; and frontotemporal dementia (ALS-FTD).

RESULTS

This study includes 33 patients with TARDBP pathogenetic variants (TARDBP-ALS) (median age 61 years [interquartile range (IQR) 53-67], 8 female [24.2%]) and 928 patients with ALS not carrying the pathogenic variant (WT-ALS) (median age 67 years [IQR 59-74], 386 female [41.6%]). TARDBP-ALS cases were also compared with 129 matched controls (median age 66 years [IQR 57.5-71.5], 55 female [42.6%]). TARDBP-ALS and WT-ALS patients were cognitively classified as ALS-CN (54% vs 58.8%, respectively), ALSci (21.2% vs 18.3%), ALSci (9.1% vs 9.5%), ALScbi (6.1% vs 6.0%), and ALS-FTD (9.1 vs 6.7%), with no significant difference (p = 0.623). Compared with controls, TARDBP-ALS had a worse performance in executive functions, visual memory, visuoconstructive abilities, verbal fluency, and the apathy behavioral component of FrSBe. The scores of performed tests, including all Edinburgh Cognitive and Behavioral ALS Screen subdomains, were similar in TARDBP-ALS and WT-ALS.

DISCUSSION

TARDBP-ALS patients were significantly more impaired than controls in most examined domains but do not show any specific pattern of cognitive impairment compared with WT-ALS. Our findings are relevant both clinically, considering the effect of cognitive impairment on patients' decision-making and caregivers' burden, and in designing clinical trials for the treatment of patients carrying TARDBP pathogenetic variants.

Cortical structure and the risk of amyotrophic lateral sclerosis: A bidirectional Mendelian randomization study

BACKGROUND

Current observational studies indicate progressive brain atrophy is closely associated with the clinical feature of amyotrophic lateral sclerosis. However, it is unclear whether the changes in cortical structure are the cause or result of ALS. Our study aimed to investigate the causal relationship between cortical structure and ALS risk using a bidirectional two-sample MR study.

METHODS

We collected publicly available genome-wide association studies' summary statistics for cortical structure from UK Biobank and ENIGMA consortium (n = 33,992) and ALS from the Project MinE (n = 138,086). We used the inverse variance weighted method (IVW) as primary analysis in order to evaluate the causal effects. In addition, the weighted median and MR Egger methods were performed to ensure the robustness and reliability of the IVW results.

RESULTS

We found the decreased surface of the paracentral lobule and thickness of the frontal pole and middle temporal lobe were suggestively associated with an increased risk of ALS as well as the increased surface of medial orbitofrontal and middle temporal lobe. In another aspect, the causalities between the susceptibility to ALS and the volume of the transverse temporal gyrus and superior temporal gyrus were negative. Besides, the susceptibility to ALS might also contribute to an increased thickness of the postcentral gyrus and superior parietal gyrus.

CONCLUSION

In this two-sample MR analysis, we observed that multiple cortical brain regions are associated with a higher ALS risk. Further research into the underlying mechanisms is required to back up our findings.

Clinical epidemiology of amyotrophic lateral sclerosis in Liguria, Italy: a ten year follow up study

OBJECTIVE

This article presents an updated analysis of the LIGALS register, a prospective study conducted over a ten-year period (2009-2018) in Liguria, Italy, aimed at evaluating the incidence, prevalence, clinical presentation, and management of amyotrophic lateral sclerosis (ALS).

METHODS

We calculated the mean annual crude incidence rate of ALS, assessed the point prevalence of ALS on January 1, 2018, and analyzed demographic factors, clinical characteristics, and clinical management strategies. Data analysis included Cox regression analysis to identify predictors of survival.

RESULTS

The mean annual crude incidence rate of ALS was 3.16/100,000 per year (CI 95%) while the point prevalence of ALS on January 1, 2018, was 9.31/100,000 population (CI 95%). Among the patients, 6.5% were familial ALS, while 93.5% were sporadic cases. Clinical management strategies, including percutaneous endoscopic gastrostomy (PEG) and noninvasive ventilation (NIV), were employed. The study observed a stable frequency of NIV initiation and PEG placement over time, with a growing trend toward earlier PEG positioning. The mean survival from symptom onset was 39 months, whereas from diagnosis, it was 26 months. Cox regression analysis identified several predictors of survival, including gender, age at onset and diagnosis, site of onset, diagnostic category, phenotype, and diagnostic delay.

CONCLUSIONS

This comprehensive analysis provides valuable insights into the long-term trends in ALS epidemiology and clinical management in Liguria, Italy. It underscores the importance of continued research efforts in understanding and addressing the challenges posed by ALS, particularly in terms of early diagnosis and optimizing clinical interventions to improve patient outcomes.

Identifying risk loci for FTD and shared genetic component with ALS: A large-scale multitrait association analysis

Current genome-wide association studies of frontotemporal dementia (FTD) are underpowered due to limited samples. Further, common genetic etiologies between FTD and amyotrophic lateral sclerosis (ALS) remain unknown. Using the largest summary statistics of FTD (3526 cases and 9402 controls) and ALS (27,205 cases and 110,881 controls), we found a significant genetic correlation between them (rˆg = 0.637, P = 0.032) and identified 190 FTD-related variants within 5 loci (3p22.1, 5q35.1, 9p21.2, 19p13.11, and 20q13.13). Among these, ALS and FTD had causal variants in 9p21.2 and 19p13.11. Moreover, MOBP (3p22.1), C9orf72 (9p21.2), MOB3B (9p21.2), UNC13A (19p13.11), SLC9A8 (20q13.13), SNAI1 (20q13.13), and SPATA2 (20q13.13) were discovered by both SNP- and gene-level analyses, which together discovered 15 FTD-associated genes, with 10 not detected before (IFNK, RNF114, SLC9A8, SPATA2, SNAI1, SCFD1, POLDIP2, TMEM97, G2E3, and PIGW). Functional analyses showed these genes were enriched in heart left ventricle, kidney cortex, and some brain regions. Overall, this study provides insights into genetic determinants of FTD and shared genetic etiology underlying FTD and ALS.

Identifying and Diagnosing TDP-43 Neurodegenerative Diseases in Psychiatry

Neuropsychiatric symptoms (NPS) are common manifestations of neurodegenerative disorders and are often early signs of those diseases. Among those neurodegenerative diseases, TDP-43 proteinopathies are an increasingly recognized cause of early neuropsychiatric manifestations. TDP-43-related diseases include frontotemporal dementia (FTD), amyotrophic lateral sclerosis (ALS), and Limbic-Predominant Age-Related TDP-43 Encephalopathy (LATE). The majority of TDP-43-related diseases are sporadic, but a significant proportion is hereditary, with progranulin (GRN) mutations and C9orf72 repeat expansions as the most common genetic etiologies. Studies reveal that NPS can be the initial manifestation of those diseases or can complicate disease course, but there is a lack of awareness among clinicians about TDP-43-related diseases, which leads to common diagnostic mistakes or delays. There is also emerging evidence that TDP-43 accumulations could play a role in late-onset primary psychiatric disorders. In the absence of robust biomarkers for TDP-43, the diagnosis remains primarily based on clinical assessment and neuroimaging. Given the association with psychiatric symptoms, clinical psychiatrists have a key role in the early identification of patients with TDP-43-related diseases. This narrative review provides a comprehensive overview of the pathobiology of TDP-43, resulting clinical presentations, and associated neuropsychiatric manifestations to help guide clinical practice.

Impairment of oculomotor functions in patients with early to advanced amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) can result into an incomplete locked in state (iLIS), in which communication depends on eye tracking computer devices. Oculomotor function impairments in ALS have been reported, but there is little research, particularly with respect to patients in iLIS. In the present study, we compared reflexive and executive oculomotor function by means of an eye tracking test battery between three groups: advanced ALS patients in iLIS (n = 22), patients in early to middle ALS stages (n = 44) and healthy subjects (n = 32). Patients with ALS showed significant deteriorations in oculomotor functions, with stronger impairments in iLIS. More specifically, ALS patients produced visually guided prosaccades with longer latencies and more frequent hypometria compared to healthy subjects. Longest latencies were obtained in iLIS patients, with a stronger prolongation for vertical than for horizontal prosaccades. ALS patients made more antisaccade errors and generated antisaccades with longer latencies. Smooth pursuit was also impaired in ALS. In the earlier ALS stages, bulbar onset patients presented stronger antisaccade and smooth pursuit deficits than spinal onset patients. Our findings reveal a relevant deterioration of important oculomotor functions in ALS, which increases in iLIS. It includes impairments of reflexive eye movements to loss of executive inhibitory control, indicating a progressing pathological involvement of prefrontal, midbrain and brainstem areas. The assessment of oculomotor functions may therefore provide clinically relevant bio- and progression marker, particularly in advanced ALS.

Shared and Unique Disease Pathways in Amyotrophic Lateral Sclerosis and Parkinson's Disease Unveiled in Peripheral Blood Mononuclear Cells

Recent evidence supports an association between amyotrophic lateral sclerosis (ALS) and Parkinson's disease (PD). Indeed, prospective population-based studies demonstrated that about one-third of ALS patients develop parkinsonian (PK) signs, even though different neuronal circuitries are involved. In this context, proteomics represents a valuable tool to identify unique and shared pathological pathways. Here, we used two-dimensional electrophoresis to obtain the proteomic profile of peripheral blood mononuclear cells (PBMCs) from PD and ALS patients including a small cohort of ALS patients with parkinsonian signs (ALS-PK). After the removal of protein spots correlating with confounding factors, we applied a sparse partial least square discriminant analysis followed by recursive feature elimination to obtain two protein classifiers able to discriminate (i) PD and ALS patients (30 spots) and (ii) ALS-PK patients among all ALS subjects (20 spots). Functionally, the glycolysis pathway was significantly overrepresented in the first signature, while extracellular interactions and intracellular signaling were enriched in the second signature. These results represent molecular evidence at the periphery for the classification of ALS-PK as ALS patients that manifest parkinsonian signs, rather than comorbid patients suffering from both ALS and PD. Moreover, we confirmed that low levels of fibrinogen in PBMCs is a characteristic feature of PD, also when compared with another movement disorder. Collectively, we provide evidence that peripheral protein signatures are a tool to differentially investigate neurodegenerative diseases and highlight altered biochemical pathways.

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.

Advances in molecular pathology, diagnosis, and treatment of amyotrophic lateral sclerosis

Although the past two decades have produced exciting discoveries in the genetics and pathology of amyotrophic lateral sclerosis (ALS), progress in developing an effective therapy remains slow. This review summarizes the critical discoveries and outlines the advances in disease characterization, diagnosis, imaging, and biomarkers, along with the current status of approaches to ALS care and treatment. Additional knowledge of the factors driving disease progression and heterogeneity will hopefully soon transform the care for patients with ALS into an individualized, multi-prong approach able to prevent disease progression sufficiently to allow for a dignified life with limited disability.

Motor neurone disease: A point-prevalence study of patient reported symptom prevalence, severity and palliative care needs

BACKGROUND

Motor neurone disease is a rare but debilitating illness with incomplete evidence regarding patients' symptom burden. Palliative care and generalist clinicians are often in-experienced in caring for these patients and assessing their needs.

AIM

To identify the symptom prevalence and severity experienced by patients with motor neurone disease. Secondary objectives were to examine differences in symptom burden and clusters according to phenotype, functional status, palliative care provision and those in their last months of life.

DESIGN

A point prevalence study assessing patient-reported symptoms using a modified IPOS-Neuro assessment tool, incorporating 41 symptom items.

SETTING/PARTICIPANTS

Patients with motor neurone disease attending the State-wide Progressive Neurological Disease Service or inpatient unit at Calvary Health Care Bethlehem, Melbourne Australia, from March to December 2021.

RESULTS

A total of 102 patients participated, the majority diagnosed with lumber-onset (30.4%), bulbar-onset (28.4%) and cervical-onset (25.5%) phenotypes. Patients experienced a median of 17 symptoms (range 2-32) with a median of 3 symptoms rated as severe/overwhelming (range 0-13). Motor and functional symptoms predominated, with differences in symptom clusters present according to phenotype. Patients had a higher number of severe/overwhelming symptoms if they were accessing palliative care services (p = 0.005), in their last 6 months of life (p = 0.003) and experiencing moderate or severe functional impairment (p < 0.001).

CONCLUSIONS

Patients with motor neurone disease report high symptom burden. A validated motor neurone disease-specific symptom assessment tool is needed to accurately assess patients, including important variations in symptom clusters according to phenotype. Further research must focus on evidence-based treatment guidelines for symptoms experienced commonly and severely.

MRI biomarkers for memory-related impairment in amyotrophic lateral sclerosis: a systematic review

Introduction: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder associated with cognitive and behavioral impairments and motor symptoms. Magnetic resonance imaging (MRI) biomarkers have been investigated as potential tools for detecting and monitoring memory-related impairment in ALS. Our objective was to examine the importance of identifying MRI biomarkers for memory-related impairment in ALS, motor neuron disease (MND), and ALS frontotemporal dementia (FTD) (ALS-FTD) patients. Methods: PubMed and Scopus databases were searched. Keywords covering magnetic resonance imaging, ALS, MND, and memory impairments were searched. There were a total of 25 studies included in our work here. Results: The structural MRI (sMRI) studies reported gray matter (GM) atrophy in the regions associated with memory processing, such as the hippocampus and parahippocampal gyrus (PhG), in ALS patients. The diffusion tensor imaging (DTI) studies showed white matter (WM) alterations in the corticospinal tract (CST) and other tracts that are related to motor and extra-motor functions, and these alterations were associated with memory and executive function impairments in ALS. The functional MRI (fMRI) studies also demonstrated an altered activation in the prefrontal cortex, limbic system, and other brain regions involved in memory and emotional processing in ALS patients. Conclusion: MRI biomarkers show promise in uncovering the neural mechanisms of memory-related impairment in ALS. Nonetheless, addressing challenges such as sample sizes, imaging protocols, and longitudinal studies is crucial for future research. Ultimately, MRI biomarkers have the potential to be a tool for detecting and monitoring memory-related impairments in ALS.

Iranian clinical practice guideline for amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegeneration involving motor neurons. The 3-5 years that patients have to live is marked by day-to-day loss of motor and sometimes cognitive abilities. Enormous amounts of healthcare services and resources are necessary to support patients and their caregivers during this relatively short but burdensome journey. Organization and management of these resources need to best meet patients' expectations and health system efficiency mandates. This can only occur in the setting of multidisciplinary ALS clinics which are known as the gold standard of ALS care worldwide. To introduce this standard to the care of Iranian ALS patients, which is an inevitable quality milestone, a national ALS clinical practice guideline is the necessary first step. The National ALS guideline will serve as the knowledge base for the development of local clinical pathways to guide patient journeys in multidisciplinary ALS clinics. To this end, we gathered a team of national neuromuscular experts as well as experts in related specialties necessary for delivering multidisciplinary care to ALS patients to develop the Iranian ALS clinical practice guideline. Clinical questions were prepared in the Patient, Intervention, Comparison, and Outcome (PICO) format to serve as a guide for the literature search. Considering the lack of adequate national/local studies at this time, a consensus-based approach was taken to evaluate the quality of the retrieved evidence and summarize recommendations.

Memory-guided navigation in amyotrophic lateral sclerosis

BACKGROUND

Previous studies have yielded inconsistent results about hippocampal involvement in non-demented patients with amyotrophic lateral sclerosis (ALS). We hypothesized that testing of memory-guided spatial navigation i.e., a highly hippocampus-dependent behaviour, might reveal behavioural correlates of hippocampal dysfunction in non-demented ALS patients.

METHODS

We conducted a prospective study of spatial cognition in 43 non-demented ALS outpatients (11f, 32 m, mean age 60.0 years, mean disease duration 27.0 months, mean ALSFRS-R score 40.0) and 43 healthy controls (14f, 29 m, mean age 57.0 years). Participants were tested with a virtual memory-guided navigation task derived from animal research ("starmaze") that has previously been used in studies of hippocampal function. Participants were further tested with neuropsychological tests of visuospatial memory (SPART, 10/36 Spatial Recall Test), fluency (5PT, five-point test) and orientation (PTSOT, Perspective Taking/Spatial Orientation Test).

RESULTS

Patients successfully learned and navigated the starmaze from memory, both in conditions that forced memory of landmarks (success: patients 50.7%, controls 47.7%, p = 0.786) and memory of path sequences (success: patients 96.5%, controls 94.0%, p = 0.937). Measures of navigational efficacy (latency, path error and navigational uncertainty) did not differ between groups (p ≥ 0.546). Likewise, SPART, 5PT and PTSOT scores did not differ between groups (p ≥ 0.238).

CONCLUSIONS

This study found no behavioural correlate for hippocampal dysfunction in non-demented ALS patients. These findings support the view that the individual cognitive phenotype of ALS may relate to distinct disease subtypes rather than being a variable expression of the same underlying condition.

Motor symptoms in genetic frontotemporal dementia: developing a new module for clinical rating scales

OBJECTIVE

To investigate the optimal method of adding motor features to a clinical rating scale for frontotemporal dementia (FTD).

METHODS

Eight hundred and thirty-two participants from the international multicentre Genetic FTD Initiative (GENFI) study were recruited: 522 mutation carriers (with C9orf72, GRN and MAPT mutations) and 310 mutation-negative controls. A standardised clinical questionnaire was used to assess eight motor symptoms (dysarthria, dysphagia, tremor, slowness, weakness, gait disorder, falls and functional difficulties using hands). Frequency and severity of each motor symptom was assessed, and a principal component analysis (PCA) was performed to identify how the different motor symptoms loaded together. Finally, addition of a motor component to the CDR® plus NACC FTLD was investigated (CDR® plus NACC FTLD-M).

RESULTS

24.3% of mutation carriers had motor symptoms (31.7% C9orf72, 18.8% GRN, 19.3% MAPT) compared to 6.8% of controls. Slowness and gait disorder were the commonest in all genetic groups while tremor and falls were the least frequent. Symptom severity scores were similar to equivalent physical motor examination scores. PCA revealed that all motor symptoms loaded together so a single additional motor component was added to the CDR® plus NACC FTLD to form the CDR® plus NACC FTLD-M. Individual global scores were more severe with the CDR® plus NACC FTLD-M, and no patients with a clinically diagnosed motor disorder (ALS/FTD-ALS or parkinsonism) were classified anymore as asymptomatic (unlike the CDR® plus NACC FTLD alone).

CONCLUSIONS

Motor features are present in mutation carriers at all disease stages across all three genetic groups. Inclusion of motor symptoms in a rating scale that can be used in future clinical trials will not only ensure a more accurate severity measure is recorded but that a wider spectrum of FTD phenotypes can be included in the same trial.

Current State and Future Directions in the Diagnosis of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by loss of upper and lower motor neurons, resulting in progressive weakness of all voluntary muscles and eventual respiratory failure. Non-motor symptoms, such as cognitive and behavioral changes, frequently occur over the course of the disease. Considering its poor prognosis with a median survival time of 2 to 4 years and limited causal treatment options, an early diagnosis of ALS plays an essential role. In the past, diagnosis has primarily been determined by clinical findings supported by electrophysiological and laboratory measurements. To increase diagnostic accuracy, reduce diagnostic delay, optimize stratification in clinical trials and provide quantitative monitoring of disease progression and treatment responsivity, research on disease-specific and feasible fluid biomarkers, such as neurofilaments, has been intensely pursued. Advances in imaging techniques have additionally yielded diagnostic benefits. Growing perception and greater availability of genetic testing facilitate early identification of pathogenic ALS-related gene mutations, predictive testing and access to novel therapeutic agents in clinical trials addressing disease-modified therapies before the advent of the first clinical symptoms. Lately, personalized survival prediction models have been proposed to offer a more detailed disclosure of the prognosis for the patient. In this review, the established procedures and future directions in the diagnostics of ALS are summarized to serve as a practical guideline and to improve the diagnostic pathway of this burdensome disease.

An atypical ALS with PSP-like symptoms caused by ANXA11 p.D40G mutation: A case report and literature review

Background

ANXA11 mutations were first reported to be associated with amyotrophic lateral sclerosis (ALS) in 2017. Several studies have investigated the prevalence of ANXA11 mutations in different populations, while less is known about the spectrum of phenotypes and the genotype-phenotype correlation with this gene mutation.

Case presentation

Here, we report a 74-year-old man who was initially diagnosed with progressive supranuclear palsy (PSP) because of repeated falls, slight upward gaze palsy, and mild cognitive dysfunction at the onset. He finally turned out to be ALS with more and more prominent limb weakness and atrophy, together with the evidence of chronic neurogenic change and ongoing denervation on electromyography. Brain magnetic resonance imaging showed extensive cortical atrophy. A missense mutation c.119A > G (p.D40G) on the ANXA11 gene was identified using whole-exome sequencing, which confirmed the diagnosis of ALS. We performed a systematic review of the literature about ALS-relevant cases with ANXA11 mutations and identified 68 affected subjects and 29 variants with the ANXA11 gene. We summarized the phenotypes of ANXA11 mutations and the clinical characteristics of nine patients harboring the ANXA11 p.D40G variant including our case.

Conclusions

The phenotype of ANXA11-related cases is heterogeneous, and most cases showed typical ALS, while some could also have the characteristics of frontotemporal dementia (FTD) and PSP, even inclusion body myopathies (hIBM) occurred in familial ALS (FALS). Our patient presented with ALS with a co-morbid PSP-like symptom (ALS-PSP) phenotype, which has not been reported. Except for our patient, the remaining eight patients with the ANXA11 p.D40G variant presented with a classical ALS phenotype without cognitive impairment.

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.

Age of Onset and Length of Survival of Queensland Patients with Amyotrophic Lateral Sclerosis: Details of Subjects with Early Onset and Subjects with Long Survival

INTRODUCTION

The aims of the study were to document the characteristics of amyotrophic lateral sclerosis (ALS) patients in Queensland, to examine factors influencing age of onset, and survival, and to study those with early-onset (<45 years) disease and those with long (>5 years) survival.

METHODS

We studied subjects seen at the ALS Clinic at the Royal Brisbane and Women's Hospital. We recorded sex, age of onset, region of onset, length of survival, presence of family history, type of disease, and evidence of cognitive involvement. We analysed the influence of these features on age of onset and survival. We analysed the features of patients with early onset of disease and patients with long survival.

RESULTS

There were 855 ALS patients (505 males) in the cohort. The age of onset was lower in males than females, in patients with a family history of ALS compared to those without, and in patients with spinal onset compared to bulbar onset. Early-onset disease was seen in 10% of patients, and had a greater proportion of males, spinal onset, and classical ALS phenotype compared to late-onset disease. Survival was shorter in females, in patients with bulbar onset, and in patients with classical ALS. Long survival was seen in 18% of patients. Patients with long survival had younger age of onset, greater proportion of males, spinal onset, and fewer patients with classical ALS.

CONCLUSION

Our study confirms that ALS is more prevalent in males and that spinal onset is more common than bulbar onset. Males have earlier onset but longer survival. We found that overall, patients with classical ALS have worse survival than ALS variants, but some patients who were considered to have classical ALS had long survival. This study confirms the similarity of ALS in our region to ALS in other geographical regions.

Genotype-phenotype correlation in the spectrum of frontotemporal dementia-parkinsonian syndromes and advanced diagnostic approaches

The term frontotemporal dementia (FTD) refers to a group of progressive neurodegenerative disorders characterized mainly by atrophy of the frontal and anterior temporal lobes. Based on clinical presentation, three main clinical syndromes have traditionally been described: behavioral variant frontotemporal dementia (bvFTD), non-fluent/agrammatic primary progressive aphasia (nfPPA), and semantic variant PPA (svPPA). However, over the last 20 years, it has been recognized that cognitive phenotypes often overlap with motor phenotypes, either motor neuron diseases or parkinsonian signs and/or syndromes like progressive supranuclear palsy (PSP) and cortico-basal syndrome (CBS). Furthermore, FTD-related genes are characterized by genetic pleiotropy and can cause, even in the same family, pure motor phenotypes, findings that underlie the clinical continuum of the spectrum, which has pure cognitive and pure motor phenotypes as the extremes. The genotype-phenotype correlation of the spectrum, FTD-motor neuron disease, has been well defined and extensively investigated, while the continuum, FTD-parkinsonism, lacks a comprehensive review. In this narrative review, we describe the current knowledge about the genotype-phenotype correlation of the spectrum, FTD-parkinsonism, focusing on the phenotypes that are less frequent than bvFTD, namely nfPPA, svPPA, PSP, CBS, and cognitive-motor overlapping phenotypes (i.e. PPA + PSP). From a pathological point of view, they are characterized mainly by the presence of phosphorylated-tau inclusions, either 4 R or 3 R. The genetic correlate of the spectrum can be heterogeneous, although some variants seem to lead preferentially to specific clinical syndromes. Furthermore, we critically review the contribution of genome-wide association studies (GWAS) and next-generation sequencing (NGS) in disentangling the complex heritability of the FTD-parkinsonism spectrum and in defining the genotype-phenotype correlation of the entire clinical scenario, owing to the ability of these techniques to test multiple genes, and so to allow detailed investigations of the overlapping phenotypes. Finally, we conclude with the importance of a detailed genetic characterization and we offer to patients and families the chance to be included in future randomized clinical trials focused on autosomal dominant forms of FTLD.

Sensory Involvement in Amyotrophic Lateral Sclerosis

Although amyotrophic lateral sclerosis (ALS) is pre-eminently a motor disease, the existence of non-motor manifestations, including sensory involvement, has been described in the last few years. Although from a clinical perspective, sensory symptoms are overshadowed by their motor manifestations, this does not mean that their pathological significance is not relevant. In this review, we have made an extensive description of the involvement of sensory and autonomic systems described to date in ALS, from clinical, neurophysiological, neuroimaging, neuropathological, functional, and molecular perspectives.

A Systematic Review of Caregiver Coping Strategies in Amyotrophic Lateral Sclerosis and Frontotemporal Dementia

Caregivers of patients diagnosed with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) often experience distressing symptoms related to their caregiving role. This review evaluates the existing literature on coping and their relationship to ALS and FTD caregiver psychological wellbeing. Published articles were identified via a systematic search of four databases (Cinahl Complete, Medline, Embase and PsycINFO). Overall, problem-focused coping strategies such as active coping and planning was used most often by ALS and FTD caregivers. Positive emotion-focused coping strategies such as acceptance were also frequently used by FTD caregivers. In contrast, dysfunctional coping strategies such as self-oriented reactions including self-blame, denial and self-preoccupation appeared to be the most salient coping strategy negatively impacting on caregiver psychological wellbeing. Six different coping measures were used and their psychometric properties were typically under-reported or satisfactory at best when reported. While coping is as an important aspect of caregivers' experience, it remains unclear how the temporal dimensions of the coping process as well as stressor specificity influences psychological adaptation, and consequently, development of targeted caregiver intervention. The need for future studies to define the coping process more clearly in order to capture the unique stressors encountered by ALS and FTD caregivers throughout the different disease stages is emphasised.

Behavioral and Cognitive Phenotypes of Patients With Amyotrophic Lateral Sclerosis Carrying SOD1 Variants

BACKGROUND AND OBJECTIVES

SOD1 variants in patients with amyotrophic lateral sclerosis (ALS) have been associated with peculiar clinical features and disease progression but rarely with cognitive and behavioral impairment. This study aims at describing the features of frontotemporal syndromes in patients with ALS carrying SOD1 variants.

METHODS

Italian patients with ALS were consecutively enrolled between 2012 and 2020 at our Motor Neuron Disease Center. All underwent clinical assessment, extensive neurophysiologic test battery for the evaluation of cognitive functions and behavior, and targeted next-generation sequencing of SOD1, FUS, TARDBP, VCP, PFN1, TUBA4A, OPTN, SQSTM1, UBQLN2, and C9orf72 genes. Neuropsychological profiles of SOD1+ patients (SOD1+) were compared with those with no gene variants (SOD1-). To this aim, the occurrence of cognitive and behavioral impairment defined according to the current guidelines, the number of pathologic test performances based on Italian normative values, and scores of the Frontal Behavioral Inventory were collected.

RESULTS

Among 288 patients consecutively examined, we identified 8 known pathogenic SOD1 variants and one variant of uncertain significance (p.Ser26Asn) not previously described in 14 patients with ALS belonging to 11 families. The clinical phenotypes were mainly characterized by predominant lower motor neuron involvement with onset at the lower limbs, and one patient had bulbar onset. SOD1+ patients (n = 14) were compared with SOD1- patients (N = 274). SOD1+ patients were younger than SOD1-, and both groups had similar functional motor disabilities and disease duration. Based on the overall neuropsychological findings, the percentage of SOD1+ and SOD1- patients with altered profiles were approximately 60%. However, behavioral impairment defined by the Strong criteria, and most commonly featuring with irritability and mental rigidity, was more frequent in SOD1+ than SOD1- patients and mainly associated with variants in exon 5. Conversely, cognitive impairment was mainly found in SOD1- patients.

DISCUSSION

Our findings from a large cohort of deeply phenotyped patients with ALS demonstrated that behavioral involvement is more common than previously thought among patients harboring SOD1 variants and that it is independent from patients' age and disease stage. These findings could be relevant for the assessment of clinical trial outcomes and disease management.

Clinical and Metabolic Signature of UNC13A rs12608932 Variant in Amyotrophic Lateral Sclerosis

Background and Objectives

To characterize the clinical and cognitive behavioral phenotype and brain ¹⁸F-2-fluoro-2-deoxy-d-glucose-PET (¹⁸F-FDG-PET) metabolism of patients with amyotrophic lateral sclerosis (ALS) carrying the rs12608932 variant of the UNC13A gene.

Methods

The study population included 1,409 patients with ALS without C9orf72, SOD1, TARDBP, and FUS mutations identified through a prospective epidemiologic ALS register. Control participants included 1,012 geographically matched, age-matched, and sex-matched participants. Clinical and cognitive differences between patients carrying the C/C rs12608932 genotype and those carrying the A/A + A/C genotype were assessed. A subset of patients underwent ¹⁸F-FDG-PET.

Results

The C/C genotype was associated with an increased risk of ALS (odds ratio: 1.54, 95% confidence interval 1.18–2.01, p = 0.001). Patients with the C/C genotype were older, had more frequent bulbar onset, and manifested a higher rate of weight loss. In addition, they showed significantly reduced performance in the letter fluency test, fluency domain of Edinburgh Cognitive and Behavioural ALS Screen (ECAS) and story-based empathy task (reflecting social cognition). Patients with the C/C genotype had a shorter survival (median survival time, C/C 2.25 years, interquartile range [IQR] 1.33–3.92; A/A + C/C: 2.90 years, IQR 1.74–5.41; p = 0.0001). In Cox multivariable analysis, C/C genotype resulted to be an independent prognostic factor. Finally, patients with a C/C genotype had a specific pattern of hypometabolism on brain ¹⁸F-FDG-PET extending to frontal and precentral areas of the right hemisphere.

Discussion

C/C rs12608932 genotype of UNC13A is associated with a specific motor and cognitive/behavioral phenotype, which reflects on ¹⁸F-FDG-PET findings. Our observations highlight the importance of adding the rs12608932 variant in UNC13A to the ALS genetic panel to refine the individual prognostic prediction and reduce heterogeneity in clinical trials.

Amyotrophic Lateral Sclerosis-The Complex Phenotype-From an Epidemiological Perspective: A Focus on Extrapyramidal and Non-Motor Features

Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease (MND) and has emerged, among the disorders, with the largest increase in incidence in Western countries. Although the typical clinical phenotype of ALS involves simultaneous upper and lower motor neurons, there is growing evidence that the neurodegeneration during the course of the disease can also involve other motor and non-motor regions. In this review, we analyzed and discussed available data from epidemiological population-based studies on extrapyramidal and non-motor features during the course of ALS.

The challenge of amyotrophic lateral sclerosis descriptive epidemiology: to estimate low incidence rates across complex phenotypes in different geographic areas

PURPOSE OF REVIEW

Amyotrophic lateral sclerosis (ALS) is a rare progressive neurodegenerative disease of motor neurons with a fatal outcome. The rareness of the disease and the rapidly fatal course are the main challenges for the ALS epidemiological research. The understanding of ALS has clearly advanced in the recent years both in the genetics and in the leading pathways of disease determinants. Epidemiological research has played a primary role in these discoveries.

RECENT FINDINGS

Epidemiological studies have shown a variation of incidence, mortality and prevalence of ALS between geographical areas and different populations, supporting the notion that genetic factors, linked to populations' ancestries, along with environmental and lifestyle factors, play a significant role in the occurrence of the disease. The burden of motor neuron diseases is increasing and currently more relevant in high-income countries but increasing at the highest rate in low and middle-income countries. The ALS phenotype is not restricted to motor functions. C9orf72 repeat expansion seems to present a recognizable phenotype characterized by earlier disease onset, the presence of cognitive and behavioural impairment.

SUMMARY

Population-based disease registries have played a major role in developing new knowledge on ALS, in characterizing genotype-phenotype correlations, in discovering new genetic modifiers and finally in planning research and health services, considering the high cost of motor neuron disease care. Epidemiological research based on multicentre international collaboration is essential to provide new data on ALS, especially in some regions of the world with poor data.

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.

Alteration of interoceptive sensitivity: expanding the spectrum of behavioural disorders in amyotrophic lateral sclerosis

Background

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder with progressive loss of upper and lower motor neurons. Non-motor-symptoms, such as cognitive, emotional, autonomic, and somatosensory alterations, have been also described.

Interoception represents the link between the body and brain, since it refers to the ability to consciously perceive the physical condition of the inner body, including one’s heartbeat (i.e., interoceptive sensitivity, IS).

Objectives

To evaluate IS in ALS patients by means of a well-established task: the heartbeat perception task. Moreover, we evaluated possible correlations between IS and neuropsychological, affective, and disease-related characteristics.

Methods

Fifty-five ALS patients (mean-age = 60.3 ± 12.5 years; mean disease-duration = 20.9 ± 18.8 months) and 41 caregivers (CG) underwent the heartbeat perception task and an extensive evaluation of motor, cognitive, body awareness, affective, and emotion domains.

Results

ALS patients showed lower IS than CG (0.68 ± 0.24 vs 0.82 ± 0.16; p = 0.003). Significant correlations were found between IS and self-reported measures of alexithymia (subscale of Toronto Alexithymia scale-20 “difficulties in describing feelings”; rho =  − .391, p = .003) and interoceptive awareness (subscale of Multidimensional assessment of interoceptive awareness “not worrying about pain”; rho = .405, p = .002). No significant differences were found on questionnaires for depression and anxiety between patients with ALS and their caregivers (p > .05).

Conclusions

ALS patients show reduced interoceptive sensitivity that is associated with poorer ability to describe feelings and with lower focalization on pain, regardless of cognitive and motor impairment. Alteration of interoception may represent a specific behavioural sign within the spectrum of emotion processing deficits described in ALS patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10072-022-06231-4.

Exploring the phenotype of Italian patients with ALS with intermediate ATXN2 polyQ repeats

OBJECTIVE

To detect the clinical characteristics of patients with amyotrophic lateral sclerosis (ALS) carrying an intermediate ATXN2 polyQ number of repeats in a large population-based series of Italian patients with ALS.

METHODS

The study population includes 1330 patients with ALS identified through the Piemonte and Valle d'Aosta Register for ALS, diagnosed between 2007 and 2019 and not carrying C9orf72, SOD1, TARDBP and FUS mutations. Controls were 1274 age, sex and geographically matched Italian subjects, identified through patients' general practitioners.

RESULTS

We found 42 cases and 4 controls with≥31 polyQ repeats, corresponding to an estimated OR of 10.4 (95% CI 3.3 to 29.0). Patients with≥31 polyQ repeats (ATXN2+) compared with those without repeat expansion (ATXN2-) had more frequently a spinal onset (p=0.05), a shorter diagnostic delay (p=0.004), a faster rate of ALSFRS-R progression (p=0.004) and King's progression (p=0.004), and comorbid frontotemporal dementia (7 (28.0%) vs 121 (13.4%), p=0.037). ATXN2+ patients had a 1-year shorter survival (ATXN2+ patients 1.82 years, 95% CI 1.08 to 2.51; ATXN2- 2.84 years, 95% CI 1.67 to 5.58, p=0.0001). ATXN2 polyQ intermediate repeats was independently related to a worse outcome in Cox multivariable analysis (p=0.006).

CONCLUSIONS

In our population-based cohort, ATXN2+ patients with ALS have a distinctive phenotype, characterised by a more rapid disease course and a shorter survival. In addition, ATXN2+ patients have a more severe impairment of cognitive functions. These findings have relevant implications on clinical practice, including the possibility of refining the individual prognostic prediction and improving the design of ALS clinical trials, in particular as regards as those targeted explicitly to ATXN2.

Association between vascular risk factors and cognitive impairment in amyotrophic lateral sclerosis: a case-control study

Objective: The disease-modifying effects of type 2 diabetes mellitus (T2DM), and hyperlipidemia on the risk and prognosis of amyotrophic lateral sclerosis (ALS) have gained significant attention. We aim to evaluate the association between common vascular risk factors and cognitive impairment in patients with ALS. Methods: Patients with ALS were consecutively recruited between June 2012 and November 2019 from a tertiary referral center for ALS at the West China Hospital. Vascular risk factors (hypertension, T2DM, hyperlipidemia, overweight, and smoking) were confirmed based on clinical data. Cognitive function was evaluated by the Chinese version of Addenbrooke's Cognitive Examination-revised. With careful confounder adjustment, multivariable logistic regression analysis was performed separately and accumulatively to determine the association between cognitive impairment and vascular risk factors in ALS. Results: Of 870 patients, 266 (30.6%) had cognitive impairment. No cognitive burden from vascular risk factors was found in patients with ALS. On the contrary, we first observed that T2DM (odds ratio [OR], 0.50; 95% confidence interval [CI], 0.25-0.98; p = 0.04) and hyperlipidemia (OR, 0.50; 95% CI, 0.26-0.97; p = 0.04) showed protective effects against cognitive decline in ALS, adjusted for age, sex, educational level, site of onset, Revised-ALS Functional Rating Scale score, predominant upper motor neuron phenotype, family history of ALS, and the remaining vascular risk factors. Sensitivity analyses of sex did not substantially reverse the risk estimates. Conclusions: T2DM and hyperlipidemia decrease the risk of cognitive impairment in patients with ALS. The fitness hypothesis in ALS has been tested and expanded in our work.

TMEM106B Acts as a Modifier of Cognitive and Motor Functions in Amyotrophic Lateral Sclerosis

The transmembrane protein 106B (TMEM106B) gene is a susceptibility factor and disease modifier of frontotemporal dementia, but few studies have investigated its role in amyotrophic lateral sclerosis. The aim of this work was to assess the impact of the TMEM106B rs1990622 (A–major risk allele; G–minor allele) on phenotypic variability of 865 patients with amyotrophic lateral sclerosis. Demographic and clinical features were compared according to genotypes by additive, dominant, and recessive genetic models. Bulbar onset was overrepresented among carriers of the AA risk genotype, together with enhanced upper motor neuron involvement and poorer functional status in patients harboring at least one major risk allele (A). In a subset of 195 patients, we found that the homozygotes for the minor allele (GG) showed lower scores at the Edinburgh Cognitive and Behavioral Amyotrophic Lateral Sclerosis Screen, indicating a more severe cognitive impairment, mainly involving the amyotrophic lateral sclerosis-specific cognitive functions and memory. Moreover, lower motor neuron burden predominated among patients with at least one minor allele (G). Overall, we found that TMEM106B is a disease modifier of amyotrophic lateral sclerosis, whose phenotypic effects encompass both sites of onset and functional status (major risk allele), motor functions (both major risk and minor alleles), and cognition (minor allele).

Brain structural and perfusion changes in amyotrophic lateral sclerosis-frontotemporal dementia patients with cognitive and motor onset: a preliminary study

Amyotrophic lateral sclerosis-frontotemporal dementia (ALS-FTD) is rare but exhibits worse prognosis than either ALS or FTD alone. However, cognitive onset ALS-FTD (ALS-FTD-C) confers significantly better patient survival than does motor onset ALS-FTD (ALS-FTD-M), underscoring a meager understanding of pathological group differences. This study aimed to assess disparities in cortical atrophy and perfusion shown by patients with the above disease variants. A total of 38 participants (ALS-FTD-C, 8; ALS-FTD-M, 6; simultaneous-onset ALS-FTD [ALS-FTD-S], 4; healthy controls [HC], 20) qualified for the study and underwent magnetic resonance imaging scan. Three-dimensional T1-weighted structural brain imaging and 3D-pseudocontinuous arterial spin-labeled imaging were routinely collected. Gray matter volume (GMV) and cerebral blood flow (CBF) in ALS-FTD-C and ALS-FTD-M were compared through voxel-based analysis. Correlations between imaging parameters and clinical data were also assessed. Compared with HC, ALS-FTD had significant GMV reduction mainly in bilateral limbic system. GMV reduction in ALS-FTD-C was similar in pattern but less widespread, whereas ALS-FTD-M lacked any significant GMV reduction. In CBF analyses, ALS-FTD displayed hypoperfusion in bilateral motor cortex, frontotemporal lobe, and left basal ganglia. Hypoperfusion involved bilateral temporal lobe, prefrontal cortex, and putamen in ALS-FTD-C but was limited to left parahippocampal gyrus in ALS-FTD-M. Correlations between clinical data and GMV/CBF changes in specific regions were also identified in ALS-FTD. Group-specific patterns of cortical atrophy and perfusion were evident in ALS-FTD-C and ALS-FTD-M. ALS-FTD-C showed pronounced cortical atrophy and hypoperfusion, which were otherwise minimal in ALS-FTD-M. Above findings preliminarily revealed the pathological group differences that may help in classifying patients with ALS-FTD.

Social Cognition deficits in Amyotrophic Lateral Sclerosis: a pilot cross-sectional population-based study

Background and purpose

Social cognition (SC) deficits are included in amyotrophic lateral sclerosis (ALS)–frontotemporal spectrum disorder revised diagnostic criteria. However, SC performance among ALS patients is heterogeneous due to the phenotypic variability of the disease and the wide range of neuropsychological tools employed. The aim of the present study was to assess facial emotion recognition and theory of mind in ALS patients compared to controls and to evaluate correlations with the other cognitive domains and degree of motor impairment.

Methods

Eighty‐three patients and 42 controls underwent a cognitive evaluation and SC assessment through the Ekman 60 Faces Test (EK‐60F), the Reading the Mind in the Eyes Test–36 Faces (RMET‐36), and the Story‐Based Empathy Task (SET).

Results

ALS patients showed significantly worse performance compared to controls in EK‐60F global score (p < 0.001), recognition of disgust (p = 0.032), anger (p = 0.038), fear (p < 0.001), and sadness (p < 0.001); RMET‐36 (p < 0.001), and SET global score (p < 0.001). Also, cognitively normal patients (ALS‐CN) showed significantly worse performance compared to controls in EK‐60F global score (p < 0.001), recognition of fear (p = 0.002), sadness (p < 0.001), and SET (p < 0.001). RMET‐36 showed a significant correlation with the Category Fluency Test (p = 0.041). SC tests showed no correlation with motor impairment expressed by Amyotrophic Lateral Sclerosis Functional Rating Scale–Revised.

Conclusions

ALS patients, also when categorized as ALS‐CN, may show impairment in SC performance. The frequent identification of early SC impairment in ALS patients supports the need to routinely assess SC for its impact on end‐of‐life decisions and its potential influence on patients' quality of life.

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.

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.

Plasma Uric Acid Helps Predict Cognitive Impairment in Patients With Amyotrophic Lateral Sclerosis

Objective: Uric acid as an antioxidant plays an important role in neurodegenerative disease. Our objective is to investigate the relationship between plasma uric acid and cognitive impairment in patients with amyotrophic lateral sclerosis (ALS).

Methods: In this cross-sectional study, 124 ALS patients were screened by the Edinburgh Cognitive and Behavioral Screen (ECAS) and classified according to the revised Strong's criteria. Additionally, based on total ECAS cut-off score patients were categorized into those with cognitive impairment (ALS-cie) and those without cognitive impairment (ALS-ncie), and clinical data and uric acid level were compared between the two groups. Parameters with significant differences were further included in a multivariate linear regression analysis with ECAS score as a dependent variable. Hold-out validation was performed to evaluate the fitness of regression model.

Results: Up to 60% of ALS patients showed cognitive or/and behavioral impairment. The ALS-cie group had lower education level (p < 0.001), older age at symptom onset (p = 0.001), older age at testing (p = 0.001), and lower plasma uric acid (p = 0.01). Multivariate analysis showed increased uric acid (β = 0.214, p = 0.01), lower age at testing (β = −0.378, p < 0.001), and higher education level (β = 0.424, p < 0.001) could predict higher ECAS score (F = 19.104, R² = 0.381, p < 0.0001). Validation analysis showed that predicted ECAS score was significantly correlated with raw ECAS score in both the training set (rs = 0.621, p < 0.001) and the testing set (rs = 0.666, p < 0.001).

Conclusions: Cognitive impairment was a common feature in our Chinese ALS patients. Plasma uric acid might help evaluate the risk of cognitive impairment in ALS patients when combined with education level and age at testing.

Patterns of Language Impairment in Early Amyotrophic Lateral Sclerosis

Objective

To investigate the incidence and nature of language change and its relationship to executive dysfunction in a population-based incident amyotrophic lateral sclerosis (ALS) sample, with the hypothesis that patterns of frontotemporal involvement in early ALS extend beyond areas of executive control to regions associated with language processing.

Methods

One hundred seventeen population-based incident ALS cases without dementia and 100 controls matched by age, sex, and education were included in the study. A detailed assessment of language processing including lexical processing, word spelling, word reading, word naming, semantic processing, and syntactic/grammatical processing was undertaken. Executive domains of phonemic verbal fluency, working memory, problem-solving, cognitive flexibility, and social cognition were also evaluated.

Results

Language processing was impaired in this incident cohort of individuals with ALS, with deficits in the domains of word naming, orthographic processing, and syntactic/grammatical processing. Conversely, phonological lexical processing and semantic processing were spared. Although executive dysfunction accounted in part for impairments in grammatical and orthographic lexical processing, word spelling, reading, and naming, primary language deficits were also present.

Conclusions

Language impairment is characteristic of ALS at early stages of the disease and can develop independently of executive dysfunction, reflecting selective patterns of frontotemporal involvement at disease onset. Language change is therefore an important component of the frontotemporal syndrome associated with ALS.

[Amyotrophic lateral sclerosis and frontotemporal dementia-On the way to common gene-specific treatment approaches]

BACKGROUND

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) share common neuropathological features and in the case of a gene mutation, also a genetic cause. To date five ALS-FTD genes are described in the literature in addition to other rare variants.

OBJECTIVE

The current state of research on treatment options for ALS and FTD is presented and an outlook on possible gene-specific approaches for ALS-FTD is provided.

MATERIAL AND METHODS

Analysis of the progression of ALS and FTD research by considering the increasing state of knowledge on the underlying pathomechanisms of the diseases.

RESULTS

In addition to anti-inflammatory approaches and stabilization of protein folding, promising gene-specific treatment approaches are currently being developed, which target common causes of ALS and FTD and therefore have an effect on both diseases.

CONCLUSION

So far there are no causal treatment options for ALS and FTD. The increasing importance of genetic causes directs the focus to the development of gene-specific treatment.

Illness Cognitions in ALS: New Insights Into Clinical Management of Behavioural Symptoms

Timely management of frontotemporal dysfunction associated with amyotrophic lateral sclerosis (ALS) has important prognostic and therapeutic implications. However, there remains a paucity of research on best practise recommendations to guide the development of interventions for cognitive and behavioural symptoms as part of ALS care. Accordingly, a focus on illness perceptions may provide a preliminary framework for managing cognitive and behavioural symptoms. The aim of the present study was to explore the nature of illness perceptions among ALS patients with cognitive and behavioural symptoms. A total of 39 patients were recruited from a specialised ALS clinic. Factor analysis showed three independent and clinically interpretable factors corresponding to “cognitive and emotion related ALS perceptions,” “cognitive- specific ALS perceptions” and “ALS coherence”. Of these factors, greater perceived cognitive and emotional impacts of ALS were associated with an approximate 4-fold increased risk of behavioural changes (p < 0.05). Greater perceived cognitive and emotional impacts of ALS was also associated with more rapid disease progression (p < 0.001). As such, timely provision of intervention addressing perceptions about the impact of ALS on functioning as well as associated emotional distress may optimise clinical management of cognitive and behavioural symptoms of ALS.

Diagnostic contribution and therapeutic perspectives of transcranial magnetic stimulation in dementia

Transcranial magnetic stimulation (TMS) is a powerful tool to probe in vivo brain circuits, as it allows to assess several cortical properties such asexcitability, plasticity and connectivity in humans. In the last 20 years, TMS has been applied to patients with dementia, enabling the identification of potential markers of thepathophysiology and predictors of cognitive decline; moreover, applied repetitively, TMS holds promise as a potential therapeutic intervention. The objective of this paper is to present a comprehensive review of studies that have employed TMS in dementia and to discuss potential clinical applications, from the diagnosis to the treatment. To provide a technical and theoretical framework, we first present an overview of the basic physiological mechanisms of the application of TMS to assess cortical excitability, excitation and inhibition balance, mechanisms of plasticity and cortico-cortical connectivity in the human brain. We then review the insights gained by TMS techniques into the pathophysiology and predictors of progression and response to treatment in dementias, including Alzheimer's disease (AD)-related dementias and secondary dementias. We show that while a single TMS measure offers low specificity, the use of a panel of measures and/or neurophysiological index can support the clinical diagnosis and predict progression. In the last part of the article, we discuss the therapeutic uses of TMS. So far, only repetitive TMS (rTMS) over the left dorsolateral prefrontal cortex and multisite rTMS associated with cognitive training have been shown to be, respectively, possibly (Level C of evidence) and probably (Level B of evidence) effective to improve cognition, apathy, memory, and language in AD patients, especially at a mild/early stage of the disease. The clinical use of this type of treatment warrants the combination of brain imaging techniques and/or electrophysiological tools to elucidate neurobiological effects of neurostimulation and to optimally tailor rTMS treatment protocols in individual patients or specific patient subgroups with dementia or mild cognitive impairment.

Developments in the assessment of non-motor disease progression in amyotrophic lateral sclerosis

INTRODUCTION

The burden of non-motor symptoms is a major determinant of quality of life and outcome in amyotrophic lateral sclerosis (ALS) and has profound negative effect also on caregivers.

AREAS COVERED

Non-motor symptoms in ALS include cognitive impairment, neurobehavioral symptoms, depression and anxiety, suicidal ideation, pain, disordered sleep, fatigue, weight loss and reduced appetite, and autonomic dysfunctions. This review summarizes the measures used for the assessment of non-motor symptoms and their properties and recaps the frequency and progression of these symptoms along the course of ALS.

EXPERT OPINION

Non-motor symptoms in ALS represent a major component of the disease and span over several domains. These symptoms require a high level of medical attention and should be checked at each visit using ad hoc questionnaires and proactively treated. Several instruments assessing non-motor symptoms have been used in ALS. Specific screening questionnaires for non-motor symptoms can be used for monitoring patients during telehealth visits and for remote surveillance through sensors and apps installed on smartphones. Novel trials for non-motor symptoms treatment specifically designed for ALS are necessary to increase and refine the therapeutic armamentarium. Finally, scales assessing the most frequent and burdensome non-motor symptoms should be included in clinical trials.

Frontotemporal Pathology in Motor Neuron Disease Phenotypes: Insights From Neuroimaging

Frontotemporal involvement has been extensively investigated in amyotrophic lateral sclerosis (ALS) but remains relatively poorly characterized in other motor neuron disease (MND) phenotypes such as primary lateral sclerosis (PLS), progressive muscular atrophy (PMA), spinal muscular atrophy (SMA), spinal bulbar muscular atrophy (SBMA), post poliomyelitis syndrome (PPS), and hereditary spastic paraplegia (HSP). This review focuses on insights from structural, metabolic, and functional neuroimaging studies that have advanced our understanding of extra-motor disease burden in these phenotypes. The imaging literature is limited in the majority of these conditions and frontotemporal involvement has been primarily evaluated by neuropsychology and post mortem studies. Existing imaging studies reveal that frontotemporal degeneration can be readily detected in ALS and PLS, varying degree of frontotemporal pathology may be captured in PMA, SBMA, and HSP, SMA exhibits cerebral involvement without regional predilection, and there is limited evidence for cerebral changes in PPS. Our review confirms the heterogeneity extra-motor pathology across the spectrum of MNDs and highlights the role of neuroimaging in characterizing anatomical patterns of disease burden in vivo. Despite the contribution of neuroimaging to MND research, sample size limitations, inclusion bias, attrition rates in longitudinal studies, and methodological constraints need to be carefully considered. Frontotemporal involvement is a quintessential clinical facet of MND which has important implications for screening practices, individualized management strategies, participation in clinical trials, caregiver burden, and resource allocation. The academic relevance of imaging frontotemporal pathology in MND spans from the identification of genetic variants, through the ascertainment of presymptomatic changes to the design of future epidemiology studies.

The clinical spectrum of primary lateral sclerosis

Primary lateral sclerosis is a distinct entity that has recently been classified as a "restricted phenotype" of ALS. It is characterized by a pattern of isolated upper motor neuron involvement that often begins in the legs and spreads diffusely. Distinction from other conditions requires careful consideration of clinical presentation and time course of disease. Mills' Syndrome is a rare unilateral variant of primary lateral sclerosis. Cognitive and behavioral involvement may occur.

Studying Alzheimer disease, Parkinson disease, and amyotrophic lateral sclerosis with 7-T magnetic resonance

Ultra-high-field (UHF) magnetic resonance (MR) scanners, that is, equipment operating at static magnetic field of 7 tesla (7 T) and above, enable the acquisition of data with greatly improved signal-to-noise ratio with respect to conventional MR systems (e.g., scanners operating at 1.5 T and 3 T). The change in tissue relaxation times at UHF offers the opportunity to improve tissue contrast and depict features that were previously inaccessible. These potential advantages come, however, at a cost: in the majority of UHF-MR clinical protocols, potential drawbacks may include signal inhomogeneity, geometrical distortions, artifacts introduced by patient respiration, cardiac cycle, and motion. This article reviews the 7 T MR literature reporting the recent studies on the most widespread neurodegenerative diseases: Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis.