The El Escorial criteria: strengths and weaknesses

Tofersen and other antisense oligonucleotides in ALS

The advent of antisense oligonucleotide (ASO) therapies in neurodegenerative disorders is associated with enormous hope. Nusinersen treatment was a breakthrough intervention in the recessive disease spinal muscular atrophy, and superoxide dismutase 1 (SOD1) amyotrophic lateral sclerosis (ALS) seems to be the paradigm disease in dominant degenerative diseases. The results of treatment with the ASO tofersen in SOD1-ALS show that the drug has a convincing beneficial effect on ALS caused by SOD1 mutations, that preclinical studies in rodents predicted the therapeutic effect in the human disease, and that clinical efficacy is associated with a specific sequence of effects of the drug on mechanistic and degenerative biomarkers and, subsequently, functional outcomes such as weight stabilization and ALSFRS-R. Therefore, the enthusiasm seems to be justified; but this should be followed by an attempt to obtain further insights with the goal to improve this therapy. In particular, the following issues are only partially resolved: Which mechanisms are responsible for the clinical effect following the downregulation of SOD1 protein by ASOs? Is long-term downregulation of SOD1 function associated with side effects? Is there an autoimmune response caused by this and other ASO? Is prevention of SOD1-associated ALS possible?

Clinical features and progress in diagnosis and treatment of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease of the central nervous system. Despite a large number of studies, the current prognosis of ALS is still not ideal. This article briefly describes the clinical features including epidemiology, genetic structure and clinical manifestations, as well as the progress of new diagnostic criteria and treatment of ALS. Meanwhile, we also discussed further both developments and improvements to enhance understanding and accelerating the introduction of the effective treatments of ALS.

Coupling motor evoked potentials and brain [18F]FDG-PET in Amyotrophic Lateral Sclerosis: preliminary findings on disease severity

BACKGROUND

The diagnosis of amyotrophic lateral sclerosis (ALS) is primarily clinical, supported by the electromyographic examination to reveal signs of lower motor neuron damage. Identifying reliable markers of upper motor neuron (UMN) involvement is challenging. On this regard, the role of transcranial magnetic stimulation-induced motor-evoked potentials (TMS-MEPs), and its relationship with UMN burden, is still under investigation.

OBJECTIVE

To evaluate the ability of TMS-MEPs in delineating the neurophysiological UMN damage, and to determine the relationship between TMS-MEPs and [18F]FDG-PET measures of neural dysfunction.

METHODS

We retrospectively selected 13 ALS patients who underwent, during the diagnostic process, the TMS-MEPs and [18F]FDG-PET scans. Demographic and clinical data were collected. For the MEP evaluation, we considered normal MEP, absent MEP, or significantly increased central-motor-conduction-time. For [18F]FDG-PET, we conducted voxel-wise analyses, both at single-subject and group levels, exploring hypometabolism and hypermetabolism patterns in comparison with a large dataset of healthy controls (HC).

RESULTS

Based on TMS-MEPs, we identified 4/13 patients with normal MEP in all limbs (GROUP-NO), while 9/13 had an abnormal MEP in at least one limb (GROUP-AB). Despite the [18F]FDG-PET single-subject analysis revealed heterogenous expression of regional hypo- and hyper-metabolism patterns in the patients, the group-level analysis revealed a common hypometabolism, involving the precentral gyrus and the supplementary motor area, the paracentral lobule and the anterior cingulate cortex in the GROUP-AB. Moreover, exclusively for the GROUP-AB compared with HC, a relative hypermetabolism was observed in the right cerebellum, right inferior and middle temporal gyrus. The GROUP-NO showed no specific cluster of hypo- and hyper-metabolism compared to HC.

CONCLUSION

This study showed altered brain metabolism only in the ALS group with abnormal MEPs, suggesting an association between the two biomarkers in defining the UMN damage.

Clinical factors and vascular endothelial growth factor as determinants of disease progression in Indian patients with amyotrophic lateral sclerosis

OBJECTIVE

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder. Prognostication remains sub-optimally defined. We aimed to assess clinical determinants of disease progression rates in Indian patients with ALS and to assess the role of vascular endothelial growth factor (VEGF) in disease progression.

METHODS

In this cross-sectional study, consecutive patients with clinically definite/probable ALS according to the revised El Escorial criteria and controls were included. Patients were classified into fast or slow progressors based on disease progression rate (DPR). Serum and CSF VEGF level was assessed for patients and controls.

RESULTS

Of 142 patients recruited, 93 (65.5%) were male. Mean age at enrollment was 49.37 ± 12.65 years. Mean duration of symptoms was 20.53 ± 20.88 months. Mean DPR was 1.14 ± 0.94. Based on DPR, 81 (57%) patients were slow progressors and 61 (43%) were fast progressors. Univariate analysis demonstrated a statistically significant association of DPR with age at onset, symptom duration, time to spread, wasting of small muscles of the hand, frontal release signs, and neurophysiologic bulbar abnormalities. On multivariate analysis, age at onset and symptom duration had a significant association with disease progression. The CSF VEGF levels of ALS patients (46.18 ± 27.8) were significantly elevated compared to controls (25.95 ± 25.64 pg/ml) (p = 0.001), but not serum VEGF.

CONCLUSION

Age at symptom onset and duration of disease had a significant impact on disease progression in Indian patients with ALS. CSF VEGF levels were significantly elevated in ALS compared to controls, indicating the role of CSF VEGF as a potential biomarker.

Venous blood parameters in determination of respiratory impairment in amyotrophic lateral sclerosis

This study aimed to investigate the relationship between venous blood parameters and respiratory functions in patients with amyotrophic lateral sclerosis (ALS) and develop a model to predict respiratory impairment for individual patients with ALS. A total of 416 ALS patients were included in the study, and various hematologic and biochemical laboratory parameters as well as demographic and clinical factors were collected and compared. A multivariable logistic regression model was constructed to assess the association between FVC and venous blood biomarkers and clinical factors. The results showed that along with onset age, bulbar-onset, disease duration, BMI, eosinophil count (EO#), basophil count (BASO#), creatinine (CREA), uric acid (URCI) and low-density lipoprotein cholesterol/high-density lipoprotein cholesterol (LDL/HDL) ratio were associated with reduced FVC. The area under the ROC curve is 0.735 for the test set and 0.721 for the validation set. The study also developed a relatively acceptable model for predicting respiratory impairment in ALS patients. These findings suggest that EO#, BASO#, CREA, URIC and LDL/HDL ratio can be useful in assessing FVC in ALS and can be easily accessible, accurate, and low-cost parameters.

Potential role of vitamin D levels in amyotrophic lateral sclerosis cognitive impairment

Cognitive impairment (CI) is common in amyotrophic lateral sclerosis (ALS): a keystone is identifying factors that could potentially modify the CI course. In recent years, vitamin D is becoming a potential modificatory factor for CI in many neurological disorders. This study aimed to highlight if vitamin D deficiency correlated with CI and clinical features in a cohort of ALS patients. We included 55 ALS patients with a neuropsychological evaluation (classified with the Strong Criteria) and a vitamin D dosage at the diagnosis. We also reviewed medical records and completed data for medical history, physical and neurological examination, and functional scales. At the diagnosis, 30 patients (54%) had CI. Most patients (82%) displayed low vitamin D levels (19.87 ± 9.80 ng/ml). Comparing the vitamin D level between patients with and without CI, we observed significantly lower values in the first group (15.8 ± 8.2 vs. 22.0 ± 9.7 ng/ml, p: 0.04). In the spinal female subgroup (n = 15), we found an inverse correlation between vitamin D and bizarreness score in the cognitive estimates test (r = 0.58; p: 0.04) and a positive correlation with the Corrected Raven's Standard Progressive Matrices (r = 0.53, p: 0.04). Conversely, in the bulbar female group, we observed a correlation with the corrected direct span (r = 0.84, p: 0.03). With the log-rank survival analysis, we found that the patients with vitamin D < 10 ng/ml had a shorter disease duration (Chi: 5.78, p: 0.02). Our results indicate that levels of vitamin D can influence the cognitive status of people living with ALS and that severe deficits might be an adverse prognostic survival factor.

Discovery of Mitophagy Inhibitors with Therapeutic Potential in Different Familial Amyotrophic Lateral Sclerosis Mutations

Mitophagy is the selective degradation of mitochondria by autophagy. It promotes the turnover of mitochondria and prevents the accumulation of dysfunctional mitochondria, which can lead to cellular degeneration. Mitophagy is known to be altered in several pathological conditions, especially in neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS). We recently demonstrated an increase in autophagy flux in lymphoblasts from ALS patients bearing a mutation in SOD1. Thus, the identification of mitophagy inhibitors may be a therapeutic option to recover mitochondrial homeostasis. Here, using a phenotypic mitophagy assay, we identified a new mitophagy inhibitor, the small molecule named IGS2.7 from the MBC library. Interestingly, the treatment of different cellular and in vivo models of ALS with mutations on SOD1 and TARDBP with this inhibitor restores autophagy to control levels. These results point mitophagy inhibitors, especially IGS2.7, to a new therapeutic approach for familial ALS patients.

Clinical relevance of single-subject brain metabolism patterns in amyotrophic lateral sclerosis mutation carriers

BACKGROUND AND OBJECTIVES

The ALS diagnosis requires an integrative approach, combining the clinical examination and supporting tests. Nevertheless, in several cases, the diagnosis proves to be suboptimal, and for this reason, new diagnostic methods and novel biomarkers are catching on. The ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG)-PET could be a helpful method, but it still requires additional research for sensitivity and specificity. We performed an ¹⁸F-FDG-PET single-subject analysis in a sample of familial ALS patients carrying different gene mutations, investigating the genotype-phenotype correlations and exploring metabolism correlations with clinical and neuropsychological data.

METHODS

We included ten ALS patients with pathogenic gene mutation who underwent a complete clinical and neuropsychological evaluation and an ¹⁸F-FDG-PET scan at baseline. Patients were recruited between 2018 and 2022 at the ALS Tertiary Centre in Novara, Italy. Patients were selected based on the presence of ALS gene mutation (C9orf72, SOD1, TBK1, and KIF5A). Following a validated voxel-based Statistical Parametric Mapping (SPM) procedure, we obtained hypometabolism maps at single-subject level. We extracted regional hypometabolism from the SPM maps, grouping significant hypometabolism regions into three meta-ROIs (motor, prefrontal association and limbic). Then, the corresponding ¹⁸F-FDG-PET regional hypometabolism was correlated with clinical and neuropsychological features.

RESULTS

Classifying the patients with C9orf72-ALS based on the rate of disease progression from symptoms onset to the time of scan, we observed two different patterns of brain hypometabolism: an extensive motor and prefrontal hypometabolism in patients classified as fast progressors, and a more limited brain hypometabolism in patients grouped as slow progressors. Patients with SOD1-ALS showed a hypometabolic pattern involving the motor cortex and prefrontal association regions, with a minor involvement of the limbic regions. The patient with TBK1-ALS showed an extended hypometabolism, in limbic systems, along with typical motor involvement, while the hypometabolism in the patient with KIF5A-ALS involved almost exclusively the motor regions, supporting the predominantly motor impairment linked to this gene mutation. Additionally, we observed strong correlations between the hypometabolism in the motor, prefrontal association and limbic meta-ROI and the specific neuropsychological performances.

CONCLUSIONS

To our knowledge, this is the first study investigating brain hypometabolism at the single-subject level in genetic ALS patients carrying different mutations. Our results show high heterogeneity in the hypometabolism maps and some commonalities in groups sharing the same mutation. Specifically, in patients with C9orf72-ALS the brain hypometabolism was larger in patients classified as fast progressors than slow progressors. In addition, in the whole group, the brain metabolism showed specific correlations with clinical and neuropsychological impairment, confirming the ability of ¹⁸F-FDG-PET in revealing pattern of neuronal dysfunction, aiding the diagnostic workup in genetic ALS patients.

A Telehealth Intervention for Nutritional Counseling in Amyotrophic Lateral Sclerosis Patients

Nutritional status is one of the most relevant prognostic factors in Amyotrophic Lateral Sclerosis (ALS), and close monitoring can help avoid severe weight loss over the disease course. We describe the impact of a Chatbot webapp on improving the communications between physicians, patients, and/or caregivers for dietary monitoring. We developed a chatbot that provides patients with a tool to register their meals through an intuitive and carefully designed conversational interface. Patients recorded their dietary intake twice weekly and received an adequate nutritional recommendation monthly. We monitored their functional and nutritional parameters. The data were compared with a control group followed up by standard counseling. We enrolled 26 patients. Regarding feasibility, 96% of participants completed the three-month follow-up, and 77% ended the six months. Regarding the change in weight in the Chatbot group, we observed a weight stabilization (F = 1.874, p-value: 0.310 for changes) over the telehealth compared to the control group (F = 1.710, p-value: 0.024 for changes). A telehealth approach for nutritional support is feasible and reproducible in an ALS setting: frequent monitoring turned out to help prevent further weight loss, allowing an early nutritional strategy adjustment.

A Prediction Model for Peak Expiratory Flow Derived From Venous Blood Biomarkers and Clinical Factors in Amyotrophic Lateral Sclerosis

Although peripheral venous blood biomarkers are related to respiratory function in Amyotrophic lateral sclerosis (ALS) patients, there are still few prediction models that predict pulmonary function. This study aimed to investigate the venous blood biomarkers associated with respiratory function in patients with ALS from southwest China and to create prediction models based on those clinical biomarkers using logistic regression. A total of 319 patients with ALS from the retrospective cohort and 97 patients with ALS from the prospective cohort were enrolled in this study. A multivariable prediction model for the correlation between peak expiratory flow (PEF) and hematologic, biochemical laboratory parameters, and clinical factors in patients with ALS was created. Along with female patients, bulbar-onset, lower body mass index (BMI), later age of onset, lower level of creatinine, uric acid, triglyceride, and a higher level of high-density lipoprotein cholesterol (HDL_C) were related to reduced PEF. The area under the receiver operating characteristics (ROC) curve is.802 for the test set and.775 for the validation set. The study constructed a multivariable prediction model for PEF in patients with ALS. The results can be helpful for clinical practice to predict respiratory impairment.

The Global Burden of Motor Neuron Disease: An Analysis of the 2019 Global Burden of Disease Study

Up-to-date, accurate information on the disease burden of motor neuron disease (MND) is the cornerstone for evidence-based resource allocation and healthcare planning. We aimed to estimate the burden of MND globally from 1990 to 2019, as part of the Global Burden of Disease, Injuries and Risk Factor (GBD) study. Amyotrophic lateral sclerosis, progressive muscular atrophy, primary lateral sclerosis, pseudobulbar palsy, spinal muscular atrophy and hereditary spastic paraplegia- were included for analysis as MNDs. We measured age-standardized incidence, prevalence, death, and disability-adjusted life-years (DALYs) in 204 countries and territories worldwide from 1990 to 2019 using spatial Bayesian analyses. The effects of age, sex, and the sociodemographic index (measures of income per capita, education, and fertility) on incidence, prevalence, death, and disability-adjusted life-years due to MNDs were explored. According to 2019 GBD estimates, there were ~268,673 [95% uncertainty interval (UI), 213,893-310,663] prevalent cases and 63,700 (95% UI, 57,295-71,343) incident cases of MND worldwide. In 2019, MND caused 1,034,606 (95% UI, 979,910-1,085,401) DALYs and 39,081 (95% UI, 36,566-41,129) deaths worldwide. The age-standardized rates of prevalence, incidence, death, and DALYs for MNDs in 2019 were 3.37 (95% UI, 2.9-3.87) per 100,000 people, 0.79 (95% UI, 0.72-0.88) per 100,000 people, 0.48 (95% UI, 0.45-0.51) per 100,000 people, and 12.66 (95% UI, 11.98-13.29) per 100,000 people, respectively. The global prevalence and deaths due to MND in 2019 were increased (1.91% [95% UI, 0.61-3.42] and 12.39% [95% UI, 5.81-19.27], respectively) compared to 1990, without significant change in incidence. More than half of the prevalence and deaths due to MND occurred in three high-income regions (North America, Western Europe, and Australasia). In most cases, the prevalence, incidence, and DALYs of MNDs were high in regions with high sociodemographic index; however, in high-income East Asia, these were relatively low compared to similar sociodemographic index groups elsewhere. The burden of MND increased between 1990 and 2019. Its expected increase in the future highlights the importance of global and national healthcare planning using more objective evidence. Geographical heterogeneity in the MND burden might suggest the influences of sociodemographic status and genetic background in various regions.

Causal associations of genetic factors with clinical progression in amyotrophic lateral sclerosis

BACKGROUND AND OBJECTIVE

Recent advances in the genetic causes of ALS reveals that about 10% of ALS patients have a genetic origin and that more than 30 genes are likely to contribute to this disease. However, four genes are more frequently associated with ALS: C9ORF72, TARDBP, SOD1, and FUS. The relationship between genetic factors and ALS progression rate is not clear. In this study, we carried out a causal analysis of ALS disease with a genetics perspective in order to assess the contribution of the four mentioned genes to the progression rate of ALS.

METHODS

In this work, we applied a novel causal learning model to the CRESLA dataset which is a longitudinal clinical dataset of ALS patients including genetic information of such patients. This study aims to discover the relationship between four mentioned genes and ALS progression rate from a causation perspective using machine learning and probabilistic methods.

RESULTS

The results indicate a meaningful association between genetic factors and ALS progression rate with causality viewpoint. Our findings revealed that causal relationships between ALSFRS-R items associated with bulbar regions have the strongest association with genetic factors, especially C9ORF72; and other three genes have the greatest contribution to the respiratory ALSFRS-R items with a causation point of view.

CONCLUSIONS

The findings revealed that genetic factors have a significant causal effect on the rate of ALS progression. Since C9ORF72 patients have higher proportion compared to those carrying other three gene mutations in the CRESLA cohort, we need a large multi-centric study to better analyze SOD1, TARDBP and FUS contribution to the ALS clinical progression. We conclude that causal associations between ALSFRS-R clinical factors is a suitable predictor for designing a prognostic model of ALS.

TDP-43 Modulation by Tau-Tubulin Kinase 1 Inhibitors: A New Avenue for Future Amyotrophic Lateral Sclerosis Therapy

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease without any effective treatment. Protein TDP-43 is a pathological hallmark of ALS in both sporadic and familiar patients. Post-translational modifications of TDP-43 promote its aggregation in the cytoplasm. Tau-Tubulin kinase (TTBK1) phosphorylates TDP-43 in cellular and animal models; thus, TTBK1 inhibitors emerge as a promising therapeutic strategy for ALS. The design, synthesis, biological evaluation, kinase-ligand complex structure determination, and molecular modeling studies confirmed novel pyrrolopyrimidine derivatives as valuable inhibitors for further development. Moreover, compound 29 revealed good brain penetration in vivo and was able to reduce TDP-43 phosphorylation not only in cell cultures but also in the spinal cord of transgenic TDP-43 mice. A shift to M2 anti-inflammatory microglia was also demonstrated in vivo. Both these activities led to motor neuron preservation in mice, proposing pyrrolopyrimidine 29 as a valuable lead compound for future ALS therapy.

Lower and upper motor neuron involvement and their impact on disease prognosis in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis is a fatal neurodegenerative disease characterized by progressive muscle wasting, breathing and swallowing difficulties resulting in patient’s death in two to five years after disease onset. In amyotrophic lateral sclerosis, both upper and lower motor neurons of the corticospinal tracts are involved in the process of neurodegeneration, accounting for great clinical heterogeneity of the disease. Clinical phenotype has great impact on the pattern and rate of amyotrophic lateral sclerosis progression and overall survival prognosis. Creating more homogenous patient groups in order to study the effects of drug agents on specific manifestations of the disease is a challenging issue in amyotrophic lateral sclerosis clinical trials. Since amyotrophic lateral sclerosis has low incidence rates, conduction of multicenter trials requires certain standardized approaches to disease diagnosis and staging. This review focuses on the current approaches in amyotrophic lateral sclerosis classification and staging system based on clinical examination and additional instrumental methods, highlighting the role of upper and lower motor neuron involvement in different phenotypes of the disease. We demonstrate that both clinical and instrumental findings can be useful in evaluating severity of upper motor neuron and lower motor neuron involvement and predicting the following course of the disease. Addressing disease heterogeneity in amyotrophic lateral sclerosis clinical trials could lead to study designs that will assess drug efficacy in specific patient groups, based on the disease pathophysiology and spatiotemporal pattern. Although clinical evaluation can be a sufficient screening method for dividing amyotrophic lateral sclerosis patients into clinical subgroups, we provide proof that instrumental studies could provide valuable insights in the disease pathology.

Involvement of cortico-efferent tracts in flail arm syndrome: a tract-of-interest-based DTI study

Background

Flail arm syndrome is a restricted phenotype of motor neuron disease that is characterized by progressive, predominantly proximal weakness and atrophy of the upper limbs.

Objective

The study was designed to investigate specific white matter alterations in diffusion tensor imaging (DTI) data from flail arm syndrome patients using a hypothesis-guided tract-of-interest-based approach to identify in vivo microstructural changes according to a neuropathologically defined amyotrophic lateral sclerosis (ALS)-related pathology of the cortico-efferent tracts.

Methods

DTI-based white matter mapping was performed both by an unbiased voxel-wise statistical comparison and by a hypothesis-guided tract-wise analysis of fractional anisotropy (FA) maps according to the neuropathological ALS-propagation pattern for 43 flail arm syndrome patients vs 43 ‘classical’ ALS patients vs 40 matched controls.

Results

The analysis of white matter integrity demonstrated regional FA reductions for the flail arm syndrome group predominantly along the CST. In the tract-specific analysis according to the proposed sequential cerebral pathology pattern of ALS, the flail arm syndrome patients showed significant alterations of the specific tract systems that were identical to ‘classical’ ALS if compared to controls.

Conclusions

The DTI study including the tract-of-interest-based analysis showed a microstructural involvement pattern in the brains of flail arm syndrome patients, supporting the hypothesis that flail arm syndrome is a phenotypical variant of ALS.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-021-10854-6.

Tideglusib, a Non-ATP Competitive Inhibitor of GSK-3β as a Drug Candidate for the Treatment of Amyotrophic Lateral Sclerosis

Amyotrophic Lateral Sclerosis (ALS) is the most common degenerative motor neuron disease in adults. About 97% of ALS patients present TDP-43 aggregates with post-translational modifications, such as hyperphosphorylation, in the cytoplasm of affected cells. GSK-3β is one of the protein kinases involved in TDP-43 phosphorylation. Up-regulation of its expression and activity is reported on spinal cord and cortex tissues of ALS patients. Here, we propose the repurposing of Tideglusib, an in-house non-ATP competitive GSK-3β inhibitor that is currently in clinical trials for autism and myotonic dystrophy, as a promising therapeutic strategy for ALS. With this aim we have evaluated the efficacy of Tideglusib in different experimental ALS models both in vitro and in vivo. Moreover, we observed that GSK-3β activity is increased in lymphoblasts from sporadic ALS patients, with a simultaneous increase in TDP-43 phosphorylation and cytosolic TDP-43 accumulation. Treatment with Tideglusib decreased not only phospho-TDP-43 levels but also recovered its nuclear localization in ALS lymphoblasts and in a human TDP-43 neuroblastoma model. Additionally, we found that chronic oral treatment with Tideglusib is able to reduce the increased TDP-43 phosphorylation in the spinal cord of Prp-hTDP-43^A315T mouse model. Therefore, we consider Tideglusib as a promising drug candidate for ALS, being proposed to start a clinical trial phase II by the end of the year.

Family-based exome sequencing identifies RBM45 as a possible candidate gene for frontotemporal dementia and amyotrophic lateral sclerosis

Neurodegenerative disorders like frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) are pathologically characterized by toxic protein deposition in the cytoplasm or nucleus of affected neurons and glial cells. Many of these aggregated proteins belong to the class of RNA binding proteins (RBP), and, when mutated, account for a significant subset of familial ALS and FTD cases. Here, we present first genetic evidence for the RBP gene RBM45 in the FTD-ALS spectrum. RBM45 shows many parallels with other FTD-ALS associated genes and proteins. Multiple lines of evidence have demonstrated that RBM45 is an RBP that, upon mutation, redistributes to the cytoplasm where it co-aggregates with other RBPs into cytoplasmic stress granules (SG), evolving to persistent toxic TDP-43 immunoreactive inclusions. Exome sequencing in two affected first cousins of a heavily affected early-onset dementia family listed a number of candidate genes. The gene with the highest pathogenicity score was the RBP gene RBM45. In the family, the RBM45 Arg183* nonsense mutation co-segregated in both affected cousins. Validation in an unrelated patient (n = 548) / control (n = 734) cohort identified an additional RBM45 Arg183* carrier with bvFTD on a shared 4 Mb haplotype. Transcript and protein expression analysis demonstrated loss of nuclear RBM45, suggestive of a loss-of-function disease mechanism. Further, two more ultra-rare VUS, one in the nuclear localization signal (NLS, p.Lys456Arg) in an ALS patient and one in the intrinsically disordered homo-oligomer assembly (HOA) domain (p.Arg314Gln) in a patient with nfvPPA were detected. Our findings suggest that the pathomechanisms linking RBM45 with FTD and ALS may be related to its loss of nuclear function as a mediator of mRNA splicing, cytoplasmic retention or its inability to form homo-oligomers, leading to aggregate formation with trapping of other RBPs including TDP-43, which may accumulate into persisted TDP-43 inclusions.

Awaji criteria for the diagnosis of amyotrophic lateral sclerosis in Hanoi, Vietnam

The aim of the article was to evaluate the role of electromyography and the value of Awaji criteria for the diagnosis of ALS in the early stage. The study involves 48 patients (27 male and 21 females from 41 to 84 years old) who went to Bach Mai Hospital and Dong Do Clinic in Hanoi and were diagnosed with ALS according to Awaji criteria. All patients underwent clinical examination for ALS. The patients were examined for nerve conduction (motor and sensory conduction) using needle electromyography (EMG). Upper motor neuron (UMN) signs and lower motor neuron (LMN) signs were most common in the cervical region (89.58%), the lumbosacral region (70.83%), and the bulbar region (56.25%). The sensory nerve conduction was normal. The spontaneous activities (fasciculation, fibrillation, positive wave) accounted for more than 50% in all 4 regions: bulbar, cervical, thoracic, and lumbosacral regions. The abnormality of both clinical and electrodiagnosis was seen in the cervical region (87.5%) and lumbosacral one (70.83%) while the bulbar region and thoracic one usually had abnormal electrodiagnosis before clinical. There were 60.42% of patients with "definite ALS" by Awaji criteria. It allowed to make an earlier diagnosis cause the sensitivity of Awaji criteria (93.75%) was higher than the revised El Escorial criteria (85.42%) (p < 0.05). The needle EMG makes it possible to detect the early-stage symptoms of ALS in a situation where there are no clinical manifestations, especially in bulbar and thoracic regions.

Telehealth approach for amyotrophic lateral sclerosis patients: the experience during COVID-19 pandemic

BACKGROUND AND OBJECTIVE

Specialized multidisciplinary ALS care has been shown to extend survival and improve patient's and caregiver's quality of life. During the COVID-19 pandemic, the management of patients suddenly changed and telemedicine has been proven to be as effective as outpatient care. We elaborate the experience with Telemedicine of a Tertiary ALS Center from an Italian geographical area with high infectious risk during the COVID-19 pandemic.

METHODS

19 patients were evaluated in telemedicine by a multidisciplinary team including a neurologist (clinical evaluation, intercurrent events, and drug prescriptions); a dietician (diet and weight monitoring); a psychologist (psychological assessment and support); and a physiotherapist (physiotherapy treatment and device prescription). Telemedicine was performed using the online platform "IoMT Connected Care Platform (Ticuro Reply)."

RESULTS

All patients reported a positive perception of talking face to face with healthcare professionals and were satisfied with how the team understood their problems. During video televisits, there was a change in the patient's medication regimen in 11/19; 2/19 required pneumological evaluation and started NIV; and 9/16 patients required prescription of devices. The mean monthly decline of ALSFRS-R before televisit was 0.88 (SD 1.17) and during televisit of 0.49 (SD 0.75). Bodyweight and daily caloric content remain stable. Reduction in HADS scores and stability in ALSAQ-40 were observed.

DISCUSSION

Our study positively reproduced the multidisciplinary approach currently used with ALS patients, trying to stabilize the functional and metabolic status and improving the psychological one. Future directions include a personalized telemedicine program according to the patient's needs.

Amyotrophic Lateral Sclerosis (ALS) prediction model derived from plasma and CSF biomarkers

Amyotrophic Lateral Sclerosis (ALS) is a degenerative disorder of motor neurons which leads to complete loss of movement in patients. The only FDA approved drug Riluzole provides only symptomatic relief to patients. Early Diagnosis of the disease warrants the importance of diagnostic and prognostic models for predicting disease and disease progression respectively. In the present study we represent the predictive statistical model for ALS using plasma and CSF biomarkers. Forward stepwise (Binary likelihood) Logistic regression model is developed for prediction of ALS. The model has been shown to have excellent validity (94%) with good sensitivity (98%) and specificity (93%). The area under the ROC curve is 99.3%. Along with age and BMI, VEGF (Vascular Endothelial Growth Factor), VEGFR2 (Vascular Endothelial Growth Factor Receptor 2) and TDP43 (TAR DNA Binding Protein 43) in CSF and VEGFR2 and OPTN (Optineurin) in plasma are good predictors of ALS.

Considerations on the concept, definition, and diagnosis of amyotrophic lateral sclerosis

The concept, definition, and diagnosis of amyotrophic lateral sclerosis (ALS) currently present some problems. This article systematically reviews the literature on the history, current concepts, definition, and diagnosis of ALS, and discloses the present problems based on the retrieved literature and the authors’ clinical experience. The current concepts and definitions of ALS have not yet been unified or standardized in clinical practice, and are sometimes vague or inaccurate, which can cause difficulties for neurologists in the clinical treatment of ALS. The concept and definition of ALS need to be further ascertained, and the current diagnostic criteria for ALS require further development. The identification of effective and objective biomarkers may be a feasible method for the early and accurate diagnosis of ALS. Therefore, future research should focus on the identification of reliable biomarkers—especially neuroimaging biomarkers—through autopsy. Standardizing the concept and definition of ALS and formulating clear diagnostic criteria will largely avoid many uncertainties in the future clinical research and treatment of ALS, which will greatly benefit patients.

Detection of White Matter Ultrastructural Changes for Amyotrophic Lateral Sclerosis Characterization: A Diagnostic Study from Dti-Derived Data

In amyotrophic lateral sclerosis (ALS), magnetic resonance imaging (MRI) allows investigation at the microstructural level, employing techniques able to reveal white matter changes. In the current study, a diffusion tensor imaging (DTI) analysis, with a collection of apparent diffusion coefficient (ADC) and fractional anisotropy (FA) indexes, was performed in ALS patients to correlate geno- and phenotype features with MRI data, to investigate an in-vivo correlation of different neuropathological patterns. All patients who underwent the MR-DTI analysis were retrospectively recruited. MRI scan was collected within three months from diagnosis. FA and ADC values were collected in corpus callosum (CC), corona radiata (CR), cerebral peduncle (CR), cerebellar peduncle (CbP) and corticospinal tract at posterior limb of internal capsule (CST). DTI analysis performed in the whole ALS cohort revealed significant FA reduction and ADC increase in all selected regions, as widespread changes. Moreover, we observed a higher value of FA in rCR in bulbar patients. A positive correlation between ALS Functional Rating Scale-Revised and FA in rCP was evident. In consideration of the non-invasiveness, the reliability and the easy reproducibility of the method, we believe that brain MRI with DTI analyses may represent a valid tool usable as a diagnostic marker in ALS.

Association of Plasma Biomarkers for Angiogenesis and Proteinopathy in Indian Amyotrophic Lateral Sclerosis Patients

Background  Amyotrophic lateral sclerosis (ALS) is a rare motor neuron disease with progressive degeneration of motor neurons. Various molecules have been explored to provide the early diagnostic/prognostic tool for ALS without getting much success in the field and miscellaneous reports studied in various population. Objective  The study was aimed to see the differential expression of proteins involved in angiogenesis (angiogenin [ANG], vascular endothelial growth factor [VEGF], vascular endothelial growth factor receptor 2 [VEGFR2], etc), proteinopathy (transactive response DNA binding protein-43 [TDP-43] and optineurin [OPTN]), and neuroinflammation (monocyte chemoattractant protein-1[MCP-1]) based on the characteristics of ALS pathology. Though, suitable panel based on protein expression profile can be designed to robust the ALS identification by enhancing the prognostic and diagnostic efficacy for ALS. Methods  A total of 89 ALS patients and 98 nonneurological controls were analyzed for the protein expression. Expression of angiogenic (VEGF, VEGFR2, and ANG), neuroinflammation (MCP-1), and proteinopathy (TDP-43 and OPTN) markers were estimated in plasma of the participants. Proteins were normalized with respective value of total protein before employing statistical analysis. Results  Analysis has exhibited significantly reduced expression of angiogenic, proteinopathy, and neuroinflammation biomarkers in ALS patients in comparison to controls. Spearman's correlation analysis has showed the positive correlation to each protein. Conclusion  Altered expression of these proteins is indicating the prominent function in ALS pathology which may be interdependent and may have a synergistic role. Hence, a panel of expression can be proposed to diagnose ALS patient which may also suggest the modulation of therapeutic strategy according to expression profile of patient.

Therapeutic potential of novel Cell Division Cycle Kinase 7 inhibitors on TDP-43-related pathogenesis such as Frontotemporal Lobar Degeneration (FTLD) and amyotrophic lateral sclerosis (ALS)

TDP-43 has been identified as the major component of protein aggregates found in affected neurons in FTLD-TDP and amyotrophic lateral sclerosis (ALS) patients. TDP-43 is hyperphosphorylated, ubiquitinated, and cleaved in the C-terminus. CDC-7 was reported to phosphorylate TDP-43. There are no effective treatments for either FTLD-TDP or ALS, being a pressing need for the search of new therapies. We hypothesized that modulating CDC-7 activity with small molecules that are able to interfere with TDP-43 phosphorylation could be a good therapeutic strategy for these diseases. Here, we have studied the effects of novel brain penetrant, thiopurine-based, CDC-7 inhibitors in TDP-43 homeostasis in immortalized lymphocytes from FTLD-TDP patients, carriers of a loss-of-function GRN mutation, as well as in cells derived from sporadic ALS patients. We found that selective CDC-7 inhibitors, ERP1.14a and ERP1.28a, are able to decrease the enhanced TDP-43 phosphorylation in cells derived from FTLD-TDP and ALS patients and to prevent cytosolic accumulation of TDP-43. Moreover, treatment of FTLD-TDP lymphoblasts with CDC-7 inhibitors leads to recovering the nuclear function of TDP-43-inducing CDK6 repression. We suggest that CDC-7 inhibitors, mainly the heterocyclic compounds here shown, may be considered as promising drug candidates for the ALS/FTD spectrum.

Modern approaches in gene therapy of motor neuron diseases

Motor neuron disorders are a group of neurodegenerative diseases characterized by muscle weakness, loss of ambulation, respiratory insufficiency, leading to an early death. Spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis are the most common and fatal motor neuron diseases. The last 3 years became very successful for novel gene therapy approaches in SMA in infants. Two innovative drugs-nusinersen (Spinraza) and onasemnogene abeparvovec (Zolgensma) have been approved by health authorities. The numerous molecular and genetic overlaps between different neurodegenerative diseases are of great importance in the development of innovative therapeutic strategies, including viral vector therapy and RNA modulating approaches.

Advanced neuroimaging approaches in amyotrophic lateral sclerosis: refining the clinical diagnosis

Introduction: In the last decade, multiparametric magnetic resonance imaging (MRI) has achieved tremendous advances in applications to amyotrophic lateral sclerosis (ALS) to increase the understanding of the associated pathophysiology. The aim of this review is to summarize recent progress in the development of MRI-based techniques aiming to support the clinical diagnosis in ALS.Areas covered: The review of structural and functional MRI applications to ALS and its variants (restricted phenotypes) is focused on the potential of MRI techniques which contribute to the diagnostic work-up of patients with the clinical presentation of a motor neuron disease. The potential of specific MRI methods for patient diagnosis and monitoring is discussed, and the future design of clinical MRI applications to ALS is conceptualized.Expert opinion: Current multiparametric MRI allows for the use as a clinical biological marker and a technical instrument in the clinical diagnosis of patients with ALS and also of patients with ALS variants. Composite neuroimaging indices of specific anatomical areas derived from different MRI techniques might guide in the diagnostic applications to ALS. Such a development of ALS-specific MRI-based composite scores with sufficient discriminative power versus ALS mimics at an individual level requires standardized advanced protocols and comprehensive analysis approaches.

The revised El Escorial criteria "clinically probable laboratory supported ALS"-once a promising now a superfluous category?

Over the past two decades, the El Escorial criteria (EEC) have been used as eligibility criteria in major randomized controlled trials. One of the goals of the revised EEC was to allow earlier diagnosis and, thus earlier trial inclusion by introducing a new category, namely "clinically probable laboratory supported" ALS. This category allowed EMG findings to be taken into account assuming that EMG is more sensitive than the clinical examination in detecting lower motor neuron signs. Recently, Edaravone has been licensed in several countries for the treatment of ALS based on a randomized controlled trial in a selected group of ALS patients excluding the EEC category "clinically probable laboratory supported". The major reason was that in a post hoc analysis of the first Edaravone trial this group comprised many slow progressors. As it is unclear whether this bias towardslow progressors was a study-specific problem or related to the category itself, we performed an analysis in the PRO-ACT dataset. In the PRO-ACT dataset, progression in ALS patients included at baseline into the "clinically probable laboratory supported" category was significantly slower (-0.53 in ALSFRS/month) compared to the other EEC categories (-0.68 in ALSFRS/month; p < 0.001) and exhibited a significantly longer diagnostic delay (13.5 months vs. 11.7 months, p < 0.001). This suggests that the bias toward slow progressors in the "clinically probable laboratory supported" category is an inherent problem of the category and thus does not fulfill the previous goal of earlier diagnosis, raising several questions concerning the application of this category.

The same cortico-efferent tract involvement in progressive bulbar palsy and in 'classical' ALS: A tract of interest-based MRI study

Background

There is an ongoing debate about the concept of restricted phenotypes of amyotrophic lateral sclerosis (ALS), including progressive bulbar palsy (PBP).

Objective

The study was designed to investigate specific white matter alterations in diffusion tensor imaging (DTI) data from PBP patients using a hypothesis-guided tract-of-interest-based approach (compared with ‘classical’ ALS patients and controls) to identify in vivo microstructural changes according to the neuropathologically defined ALS-related corticoefferent tract pathology.

Methods

DTI-based white matter mapping was performed both by an unbiased voxel-wise statistical comparison and by a hypothesis-guided tract-wise analysis of fractional anisotropy (FA) maps according to the ALS-staging pattern for 23 PBP and 23 ALS patients vs 23 matched controls.

Results

The analysis of white matter integrity demonstrated regional FA reductions along the CST and also in frontal and prefrontal brain areas both in PBP patients and ALS patients with additional regional FA reduction in the pons of the PBP group. In the tract-specific analysis according to the neuropathological ALS-staging pattern, PBP and ALS patients showed identical significant alterations of ALS-related tract systems when compared with controls.

Conclusions

The DTI study including the tract-of-interest-based analysis showed the same microstructural corticoefferent involvement patterns in PBP patients as in ALS, which supports the hypothesis that PBP is a phenotypical variant of ALS.

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Neuropathological ALS-stages can be mapped in vivo in PBP.

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PBP but not classical ALS patients show regional FA reduction in the pons.

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This study supports the hypothesis that PBP is a phenotypical variant of ALS.

Machine Learning in Amyotrophic Lateral Sclerosis: Achievements, Pitfalls, and Future Directions

Background: Amyotrophic Lateral Sclerosis (ALS) is a relentlessly progressive neurodegenerative condition with limited therapeutic options at present. Survival from symptom onset ranges from 3 to 5 years depending on genetic, demographic, and phenotypic factors. Despite tireless research efforts, the core etiology of the disease remains elusive and drug development efforts are confounded by the lack of accurate monitoring markers. Disease heterogeneity, late-stage recruitment into pharmaceutical trials, and inclusion of phenotypically admixed patient cohorts are some of the key barriers to successful clinical trials. Machine Learning (ML) models and large international data sets offer unprecedented opportunities to appraise candidate diagnostic, monitoring, and prognostic markers. Accurate patient stratification into well-defined prognostic categories is another aspiration of emerging classification and staging systems. Methods: The objective of this paper is the comprehensive, systematic, and critical review of ML initiatives in ALS to date and their potential in research, clinical, and pharmacological applications. The focus of this review is to provide a dual, clinical-mathematical perspective on recent advances and future directions of the field. Another objective of the paper is the frank discussion of the pitfalls and drawbacks of specific models, highlighting the shortcomings of existing studies and to provide methodological recommendations for future study designs. Results: Despite considerable sample size limitations, ML techniques have already been successfully applied to ALS data sets and a number of promising diagnosis models have been proposed. Prognostic models have been tested using core clinical variables, biological, and neuroimaging data. These models also offer patient stratification opportunities for future clinical trials. Despite the enormous potential of ML in ALS research, statistical assumptions are often violated, the choice of specific statistical models is seldom justified, and the constraints of ML models are rarely enunciated. Conclusions: From a mathematical perspective, the main barrier to the development of validated diagnostic, prognostic, and monitoring indicators stem from limited sample sizes. The combination of multiple clinical, biofluid, and imaging biomarkers is likely to increase the accuracy of mathematical modeling and contribute to optimized clinical trial designs.

Distinct Clinical Features and Outcomes in Motor Neuron Disease Associated with Behavioural Variant Frontotemporal Dementia

AIM

To determine the motor phenotype and outcome in a clinically ascertained group of patients with motor neuron disease (MND) and frontotemporal dementia (FTD).

METHODS

This is an observational retrospective clinical study of patients fulfilling the clinical criteria for MND-FTD. A contemporary series of patients with amyotrophic lateral sclerosis (ALS) without dementia were included for comparison. Demographic, clinical, genetic, and neuropathological data were collected. A descriptive and comparative data analysis was performed.

RESULTS

We identified 22 patients with MND-FTD. Selective distal upper limb muscle weakness and atrophy with non-significant lower limb weakness during follow-up was the most frequent motor pattern, present in 18 patients - in 15 of them associated with severe dysphagia. Aspiration pneumonia was the most common cause of death (12/19; 63%) despite gastrostomy. One-third of the patients did not develop upper motor neuron dysfunction. When compared to classic ALS without dementia (n = 162), these features were significantly different. A neuro-pathological examination was performed on 7 patients, and it confirmed the presence of MND with TDP43 protein aggregates in all patients.

CONCLUSIONS

The MND-FTD patients frequently displayed a distinctive motor pattern characterized by weakness and atrophy in distal upper limb muscles and dysphagia, with no or little spreading to other regions. These features may help to define specific subgroups of patients, which is important with regard to clinical management, outcome, and research.

Cortico-efferent tract involvement in primary lateral sclerosis and amyotrophic lateral sclerosis: A two-centre tract of interest-based DTI analysis

Background

After the demonstration of a corticoefferent propagation pattern in amyotrophic lateral sclerosis (ALS) by neuropathological studies, this concept has been used for in vivo staging of individual patients by diffusion tensor imaging (DTI) techniques, both in `classical` ALS and in restricted phenotypes such as primary lateral sclerosis (PLS).

Objective

The study was designed to investigate that microstructural changes according to the neuropathologically defined ALS alteration pattern in PLS patients could be confirmed to be identical to ´classical´ ALS patients. The novelty in this approach is that the results were independent of the subject samples and the data acquisition parameters (as was validated in two samples from two different centres). That way, reproducibility across (international) centres in addition to harmonisation/standardisation of data analysis has been addressed, for the possible use of MRI-based staging to stratify patients in clinical trials.

Methods

Tractwise analysis of fractional anisotropy (FA) maps according to the ALS-staging pattern was applied to DTI data (pooled from two ALS centres) of 88 PLS patients and 88 ALS patients with a ‘classical’ phenotype in comparison to 88 matched controls in order to identify white matter integrity alterations.

Results

In the tract-specific analysis, alterations were identical for PLS and ALS in the tract systems corresponding to the ALS staging pattern, independent of the subject samples and the data acquisition parameters. The individual categorisation into ALS stages did not differ between PLS and ALS patients.

Conclusions

This DTI study in a two-centre setting demonstrated that the neuropathological stages can be mapped in vivo in PLS with high reproducibility and that PLS-associated cerebral propagation, although showing the same corticofugal patterns as ALS, might have a different time course of neuropathology, in analogy to its much slower clinical progression rates.

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Neuropathological ALS-stages are mapped in vivo in PLS with high reproducibility.

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Bicentric DTI supports the hypothesis that PLS is a phenotype variant of ALS.

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PLS-associated propagation shows corticofugal patterns resembling those observed in ALS.

MRI-Based Mapping of Cerebral Propagation in Amyotrophic Lateral Sclerosis

Neuropathological studies revealed the propagation of amyotrophic lateral sclerosis (ALS) in a sequence of four separate disease-related regional patterns. Diffusion tensor imaging (DTI)-based analysis was established for the individual mapping of sequential disease spreading in ALS as the in vivo transfer to neuroimaging. The aim of this review is to summarize cross-sectional and longitudinal results of these technical approaches in ALS as an in vivo tool to image ALS propagation stages. This concept was also applied to restricted phenotypes of ALS, e.g., lower motor neuron disease (LMND) or primary lateral sclerosis (PLS). In summary, the regional disease patterns in the course of ALS have been successfully mapped by DTI in vivo both cross-sectionally and longitudinally so that this technique might have the potential as a read-out in clinical trials.

European Association of Nuclear Medicine and European Academy of Neurology recommendations for the use of brain 18 F-fluorodeoxyglucose positron emission tomography in neurodegenerative cognitive impairment and dementia: Delphi consensus

BACKGROUND AND PURPOSE

Recommendations for using fluorodeoxyglucose positron emission tomography (FDG-PET) to support the diagnosis of dementing neurodegenerative disorders are sparse and poorly structured.

METHODS

Twenty-one questions on diagnostic issues and on semi-automated analysis to assist visual reading were defined. Literature was reviewed to assess study design, risk of bias, inconsistency, imprecision, indirectness and effect size. Critical outcomes were sensitivity, specificity, accuracy, positive/negative predictive value, area under the receiver operating characteristic curve, and positive/negative likelihood ratio of FDG-PET in detecting the target conditions. Using the Delphi method, an expert panel voted for/against the use of FDG-PET based on published evidence and expert opinion.

RESULTS

Of the 1435 papers, 58 papers provided proper quantitative assessment of test performance. The panel agreed on recommending FDG-PET for 14 questions: diagnosing mild cognitive impairment due to Alzheimer's disease (AD), frontotemporal lobar degeneration (FTLD) or dementia with Lewy bodies (DLB); diagnosing atypical AD and pseudo-dementia; differentiating between AD and DLB, FTLD or vascular dementia, between DLB and FTLD, and between Parkinson's disease and progressive supranuclear palsy; suggesting underlying pathophysiology in corticobasal degeneration and progressive primary aphasia, and cortical dysfunction in Parkinson's disease; using semi-automated assessment to assist visual reading. Panellists did not support FDG-PET use for pre-clinical stages of neurodegenerative disorders, for amyotrophic lateral sclerosis and Huntington disease diagnoses, and for amyotrophic lateral sclerosis or Huntington-disease-related cognitive decline.

CONCLUSIONS

Despite limited formal evidence, panellists deemed FDG-PET useful in the early and differential diagnosis of the main neurodegenerative disorders, and semi-automated assessment helpful to assist visual reading. These decisions are proposed as interim recommendations.

Trace elements in ALS patients and their relationships with clinical severity

An exploratory study of trace elements in ALS and their relationships with clinical severity was detected. Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder that causes irreversible damage in humans, with the consequent loss of function of motoneurons (MNs), with a prognosis up to 5 years after diagnosis. Except to genetic rare cases it is not known the etiology of the disorder. Aim of our research is to investigate the possible role of heavy metals in the severity of the disease. In this study, by the use of plasma mass (ICP-MS), we have analyzed the content of essential and heavy metals such: Pb, Cd, Al, Hg, Mn, Fe, Cu, Zn, Se, Mg, and Ca, in blood, urine and hair of ALS patients and controls; moreover we divided the patients in two groups for disease severity and analyzed the difference among the groups, in order to study a possible involvement of metals in the severity of the damage. Our results suggest a protective role of Selenium, involved in protective antioxidant mechanisms, and a risk factor in the case of presence of Lead in blood. The levels of the other metals are not easy to interpret, because these may be due to life style and for essential metals a consequence of the disease condition, not a cause.

Identical patterns of cortico-efferent tract involvement in primary lateral sclerosis and amyotrophic lateral sclerosis: A tract of interest-based MRI study

Background

There is an ongoing debate whether primary lateral sclerosis (PLS) should be regarded as an independent disease entity separate from amyotrophic lateral sclerosis (ALS) or as a slowly progressive variant of ALS.

Objective

The study was designed to investigate specific white matter alterations in diffusion tensor imaging (DTI) data from PLS patients by a hypothesis-guided tract-of-interest-based approach compared with ‘classical’ ALS patients and healthy controls, in order to identify microstructural changes according to the neuropathologically defined ALS affectation pattern in vivo.

Methods

DTI-based white matter mapping was performed both by an unbiased voxelwise statistical comparison and by a hypothesis-guided tractwise analysis of fractional anisotropy (FA) maps according to the ALS-staging pattern for 50 PLS and 50 ALS patients vs 50 matched controls.

Results

The analysis of white matter integrity by regional FA reductions demonstrated the characteristic alteration patterns along the CST and also in frontal and prefrontal brain areas in PLS patients and ALS patients. In the tract-specific analysis according to the ALS-staging pattern, PLS and ALS affectation patterns showed identical significant alterations of ALS-related tract systems when compared with controls and no differences when compared with each other.

Conclusions

This DTI study showed the same microstructural affectation patterns in PLS patients as in ALS, in support of the hypothesis that PLS is a phenotypical variant of ALS.

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PLS showed significant alterations in ALS-related tract systems.

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DTI shows identical microstructural alteration patterns of PLS and ALS in vivo.

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DTI supports the hypothesis that PLS is a phenotypical variant of ALS.

Late age onset of amyotrophic lateral sclerosis is often not considered in elderly people

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease causing an upper and lower motor neuron loss. It is neurology textbook knowledge that the mean age of onset is about 60 years. However, recent investigations show an increasing incidence in older persons. We therefore evaluated whether ALS is potentially not considered in elderly people with ALS symptoms, respectively, not recognized.

MATERIALS AND METHODS

We included retrospectively all patients with ALS diagnoses after work-up that were admitted to our neurological and geriatric departments from 2007 to 2010 and collected their clinical data. The diagnosis of ALS was based on the El Escorial criteria. Patients were grouped into three categories according to age (<50, between 50 and 70, >70), and differences in clinical and/ or biographical factors were investigated.

RESULTS

We identified 35 patients (18 men and 17 women) with a median age at onset of 71.5 years (range: 36-87 years). When establishing the diagnosis, 51% were older than 70 years, 40% (14/35) between 50 and 70, and only 9% younger than 50. Only in 46 per cent of patients who were sent to our departments with ALS symptoms ALS was considered by the referring physician.

CONCLUSION

Late age onset of ALS seems to be more common than formerly assumed and is presumably under-recognized in elderly patients. ALS needs to be considered as a differential diagnosis in older patients. Potential factors accounting for older people being underdiagnosed with ALS relate to frequent presentation with symptoms like dysphagia, frailty or general weakness for other reasons.

Diagnostic contribution of magnetic resonance imaging in an atypical presentation of motor neuron disease

Motor neuron disease (MND) is a neurodegenerative disease determining progressive and relentless motor deterioration involving both upper and lower motor neurons (UMN and LMN); several variants at onset are described. Here we describe a case of MND presenting as pure spastic monoparesis in which magnetic resonance imaging (MRI) gave a substantial contribution in confirming the diagnosis and assessing the severity of UMN involvement. An isolated pyramidal syndrome, with complete absence of LMN signs, is a rare phenotype in the context of MND (less than 4% of total cases), especially if restricted to only one limb. Several other elements made this case an unusual presentation of MND: the late age of onset (8^th decade), the subacute evolution of symptoms (raising the suspicion of an ischemic or inflammatory, rather than degenerative, etiology), the patient's past medical history (achalasia, erythema nodosum), the increase of inflammatory indices. Conventional MRI showed no focal lesions that could explain the clinical features; therefore, we used advanced MR sequences. Diffusion tensor imaging (DTI) evaluation evidenced bilateral impairment of corticospinal tract (CST) diffusion metrics, with clear right-left asymmetry, pointing to a neurodegenerative etiology, which clinically appeared less likely at that time. Magnetic resonance spectroscopy (MRS) showed a significant reduction of NAA/Cho + Cr ratio in the motor cortex (MC), further supporting the hypothesis of UMN degeneration. In conclusion, in this particular case of MND, whose nosographic framing has not been fully defined, advanced MRI techniques with DTI and MRS proved to be of great usefulness in confirming a diffuse UMN involvement, possibly at a more advanced stage than its clinical expression.

What is in the Literature?

This edition of "What is in the Literature?" will focus on motor neuron disease (MND), including adult forms [amyotrophic lateral sclerosis (ALS), progressive muscular atrophy (PMA), primary lateral sclerosis (PLS), progressive bulbar palsy (PBA), and monomelic mononeuropathy (MMND)], and childhood forms [spinal muscle atrophy (SMA)].

Percutaneous endoscopic gastrostomy versus fluoroscopic gastrostomy in amyotrophic lateral sclerosis (ALS) sufferers with nutritional impairment: A meta-analysis of current studies

Gastrostomy is recommended for Amyotrophic Lateral Sclerosis (ALS) patients with malnutrition. There are two main methods of gastrostomy insertion: Percutaneous Endoscopic Gastrostomy (PEG) and Fluoroscopic Gastrostomy (FG). The latter included Radiologically Inserted Gastrostomy (RIG) and Per-oral Image-Guided Gastrostomy (PRG). A meta-analysis was conducted to compare these approaches in terms of survival outcomes, pain occurrence and success rate, through the literature search in PubMed, Web of Science and Cochrane Library. A total of 7 studies with 701 cases (322 in PEG, 264 in RIG and 115 in PRG) were enrolled in the final analysis. The lack of differences between the comparisons (PEG vs. PRG, PEG vs. RIG and PEG vs. PRG+RIG) on 30-day mortality and survival length was confirmed. For the pooling analysis of peri- and post-procedural complications, patients with PEG had a lower incidence of pain than cases with PRG and RIG together (P < 0.001). The same trends could be found when compared with PRG and RIG, separately (P < 0.05 and P < 0.001, respectively). And PEG showed a lower rate of successful attempts than PEG and RIG (P < 0.05). For other complications, we didn't find any differences. This meta-analysis demonstrates that PEG, PRG and RIG had their intrinsic advantages. The current evidences could not determine the preference of them. Further investigations should be done to reveal the most appropriate method for ALS patients.

Amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis is characterised by the progressive loss of motor neurons in the brain and spinal cord. This neurodegenerative syndrome shares pathobiological features with frontotemporal dementia and, indeed, many patients show features of both diseases. Many different genes and pathophysiological processes contribute to the disease, and it will be necessary to understand this heterogeneity to find effective treatments. In this Seminar, we discuss clinical and diagnostic approaches as well as scientific advances in the research fields of genetics, disease modelling, biomarkers, and therapeutic strategies.

Fast progressive lower motor neuron disease is an ALS variant: A two-centre tract of interest-based MRI data analysis

Background

The criteria for assessing upper motor neuron pathology in pure lower motor neuron disease (LMND) still remain a major issue of debate with respect to the clinical classification as an amyotrophic lateral sclerosis (ALS) variant.

Objective

The study was designed to investigate white matter damage by a hypothesis-guided tract-of-interest-based approach in patients with LMND compared with healthy controls and ´classical´ ALS patients in order to identify in vivo brain structural changes according to the neuropathologically defined ALS affectation pattern. Data were pooled from two previous studies at two different study sites (Ulm, Germany and Milano, Italy).

Methods

DTI-based white matter integrity mapping was performed by voxelwise statistical comparison and by a tractwise analysis of fractional anisotropy (FA) maps according to the ALS-staging pattern for 65 LMND patients (clinically differentiated in fast and slow progressors) vs. 92 matched controls and 101 ALS patients with a ‘classical’ phenotype to identify white matter structural alterations.

Results

The analysis of white matter structural connectivity by regional FA reductions demonstrated the characteristic alteration patterns along the CST and also in frontal and prefrontal brain areas in LMND patients compared to controls and ALS. Fast progressing LMND showed substantial involvement, like in ALS, while slow progressors showed less severe alterations. In the tract-specific analysis according to the ALS-staging pattern, fast progressing LMND showed significant alterations of ALS-related tract systems as compared to slow progressors and controls.

Conclusions

This study showed an affectation pattern for corticoefferent fibers in LMND with fast disease progression as defined for ALS, that way confirming the hypothesis that fast progressing LMND is a phenotypical variant of ALS.

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LMND is associated with brain alterations along the CST and in frontal areas.

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Fast progressive LMND show cerebral tract involvement like in ALS.

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DTI supports that fast progressive LMND is a phenotypical variant of ALS.

Amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease, is characterized by the degeneration of both upper and lower motor neurons, which leads to muscle weakness and eventual paralysis. Until recently, ALS was classified primarily within the neuromuscular domain, although new imaging and neuropathological data have indicated the involvement of the non-motor neuraxis in disease pathology. In most patients, the mechanisms underlying the development of ALS are poorly understood, although a subset of patients have familial disease and harbour mutations in genes that have various roles in neuronal function. Two possible disease-modifying therapies that can slow disease progression are available for ALS, but patient management is largely mediated by symptomatic therapies, such as the use of muscle relaxants for spasticity and speech therapy for dysarthria.

Characteristics and Prognosis of Oldest Old Subjects with Amyotrophic Lateral Sclerosis

BACKGROUND

Amyotrophic Lateral Sclerosis (ALS) is an age-related neurodegenerative disease with unclear characteristics and prognosis in the oldest old (80 years and over). The aim of this study was to compare the oldest old and younger ALS patients in terms of clinical and socio-demographic characteristics, and prognosis.

METHODS

ALS incident cases from the register of ALS in Limousin (FRALim), diagnosed between January 2000 and July 2013, were included. Descriptive and comparative analyses by age group were carried out. For time to event univariate analysis, Kaplan-Meier estimator and log rank test were used. Univariate and multivariate survival analyses were carried out with Cox's proportional hazard model.

RESULTS

Out of 322 patients, 50 (15.5%) were aged 80 or over ("oldest old" ALS) at the time of diagnosis. Among them, the male:female gender-ratio was 1.27, and 32.6% had a bulbar onset (not different from subjects aged less than 80 years). With increasing age, there was a worsening of the clinical state of the patients at time of diagnosis in terms of weight loss, forced vital capacity, ALSFRS-R and manual muscular testing. Access to ALS referral centres decreased with age, and the use of riluzole tended to be lower in the oldest old group. The median survival of oldest old patients appeared to be 10 months shorter than that of subjects aged less than 80 years (7.4 vs. 17.4 months).

CONCLUSION

The survival of oldest old ALS patients is particularly short. It relates to prognostic features at baseline and to an independent effect of advanced age.

Multimodal structural MRI in the diagnosis of motor neuron diseases

This prospective study developed an MRI-based method for identification of individual motor neuron disease (MND) patients and test its accuracy at the individual patient level in an independent sample compared with mimic disorders. 123 patients with amyotrophic lateral sclerosis (ALS), 44 patients with predominantly upper motor neuron disease (PUMN), 20 patients with ALS-mimic disorders, and 78 healthy controls were studied. The diagnostic accuracy of precentral cortical thickness and diffusion tensor (DT) MRI metrics of corticospinal and motor callosal tracts were assessed in a training cohort and externally proved in a validation cohort using a random forest analysis. In the training set, precentral cortical thickness showed 0.86 and 0.89 accuracy in differentiating ALS and PUMN patients from controls, while DT MRI distinguished the two groups from controls with 0.78 and 0.92 accuracy. In ALS vs controls, the combination of cortical thickness and DT MRI metrics (combined model) improved the classification pattern (0.91 accuracy). In the validation cohort, the best accuracy was reached by DT MRI (0.87 and 0.95 accuracy in ALS and PUMN vs mimic disorders). The combined model distinguished ALS and PUMN patients from mimic syndromes with 0.87 and 0.94 accuracy. A multimodal MRI approach that incorporates motor cortical and white matter alterations yields statistically significant improvement in accuracy over using each modality separately in the individual MND patient classification. DT MRI represents the most powerful tool to distinguish MND from mimic disorders.

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Motor cortical and white matter alterations yield high accuracy in the individual MND patient classification.

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DT MRI represents the most powerful tool to distinguish MND from mimic disorders.

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The most pronounced damage in MND patients relative to mimic subjects was found in the motor callosal fibers.

Genetic epidemiology of amyotrophic lateral sclerosis: a systematic review and meta-analysis

BACKGROUND

Genetic studies have shown that C9orf72, SOD1, TARDBP and FUS are the most common mutated genes in amyotrophic lateral sclerosis (ALS). Here, we performed a meta-analysis to determine the mutation frequencies of these major ALS-related genes in patients with ALS.

METHODS

We performed an extensive literature research to identify all original articles reporting frequencies of C9orf72, SOD1, TARDBP and FUS mutations in ALS. The mutation frequency and effect size of each study were combined. Possible sources of heterogeneity across studies were determined by meta-regression, sensitivity analysis and subgroup analysis.

RESULTS

111 studies were included in the meta-analysis. The overall pooled mutation frequencies of these major ALS-related genes were 47.7% in familial amyotrophic lateral sclerosis (FALS) and 5.2% in sporadic ALS (SALS). A significant difference was identified regarding the frequencies of mutations in major ALS genes between European and Asian patients. In European populations, the most common mutations were the C9orf72 repeat expansions (FALS 33.7%, SALS 5.1%), followed by SOD1 (FALS 14.8%, SALS 1.2%), TARDBP (FALS 4.2%, SALS 0.8%) and FUS mutations (FALS 2.8%, SALS 0.3%), while in Asian populations the most common mutations were SOD1 mutations (FALS 30.0%, SALS 1.5%), followed by FUS (FALS 6.4%, SALS 0.9%), C9orf72 (FALS 2.3%, SALS 0.3%) and TARDBP (FALS 1.5%, SALS 0.2%) mutations.

CONCLUSIONS

These findings demonstrated that the genetic architecture of ALS in Asian populations is distinct from that in European populations, which need to be given appropriate consideration when performing genetic testing of patients with ALS.

Amyotrophic lateral sclerosis: moving towards a new classification system

Amyotrophic lateral sclerosis is a progressive adult-onset neurodegenerative disease that primarily affects upper and lower motor neurons, but also frontotemporal and other regions of the brain. The extent to which each neuronal population is affected varies between individuals. The subsequent patterns of disease progression form the basis of diagnostic criteria and phenotypic classification systems, with considerable overlap in the clinical terms used. This overlap can lead to confusion between diagnosis and phenotype. Formal classification systems such as the El Escorial criteria and the International Classification of Diseases are systematic approaches but they omit features that are important in clinical management, such as rate of progression, genetic basis, or functional effect. Therefore, many neurologists use informal classification approaches that might not be systematic, and could include, for example, anatomical descriptions such as flail-arm syndrome. A new strategy is needed to combine the benefits of a systematic approach to classification with the rich and varied phenotypic descriptions used in clinical practice.

Using Eulerian video magnification to enhance detection of fasciculations in people with amyotrophic lateral sclerosis

INTRODUCTION

This study seeks to determine whether the use of Eulerian video magnification (EVM) increases the detection of muscle fasciculations in people with amyotrophic lateral sclerosis (PALS) compared with direct clinical observation (DCO).

METHODS

Thirty-second-long video recordings were taken of 9 body regions of 7 PALS and 7 controls, and fasciculations were counted by DCO during the same 30-s period. The video recordings were then motion magnified and reviewed by 2 independent assessors.

RESULTS

In PALS, median fasciculation count per body region was 1 by DCO (range 0-10) and 3 in the EVM recordings (range 0-15; P < 0.0001). EVM revealed more fasciculations than DCO in 61% of recordings. In controls, median fasciculation count was 0 for both DCO and EVM.

DISCUSSION

Compared with DCO, EVM significantly increased the detection of fasciculations in body regions of PALS. When it is used to supplement clinical examination, EVM has the potential to facilitate the diagnosis of ALS. Muscle Nerve 56: 1063-1067, 2017.