Features Of Amyotrophic Lateral Sclerosis Research Articles

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.

An interaction between synapsin and C9orf72 regulates excitatory synapses and is impaired in ALS/FTD

Dysfunction and degeneration of synapses is a common feature of amyotrophic lateral sclerosis and frontotemporal dementia (ALS/FTD). A GGGGCC hexanucleotide repeat expansion in the C9ORF72 gene is the main genetic cause of ALS/FTD (C9ALS/FTD). The repeat expansion leads to reduced expression of the C9orf72 protein. How C9orf72 haploinsufficiency contributes to disease has not been resolved. Here we identify the synapsin family of synaptic vesicle proteins, the most abundant group of synaptic phosphoproteins, as novel interactors of C9orf72 at synapses and show that C9orf72 plays a cell-autonomous role in the regulation of excitatory synapses. We mapped the interaction of C9orf72 and synapsin to the N-terminal longin domain of C9orf72 and the conserved C domain of synapsin, and show interaction of the endogenous proteins in synapses. Functionally, C9orf72 deficiency reduced the number of excitatory synapses and decreased synapsin levels at remaining synapses in vitro in hippocampal neuron cultures and in vivo in the hippocampal mossy fibre system of C9orf72 knockout mice. Consistent with synaptic dysfunction, electrophysiological recordings identified impaired excitatory neurotransmission and network function in hippocampal neuron cultures with reduced C9orf72 expression, which correlated with a severe depletion of synaptic vesicles from excitatory synapses in the hippocampus of C9orf72 knockout mice. Finally, neuropathological analysis of post-mortem sections of C9ALS/FTD patient hippocampus with C9orf72 haploinsufficiency revealed a marked reduction in synapsin, indicating that disruption of the interaction between C9orf72 and synapsin may contribute to ALS/FTD pathobiology. Thus, our data show that C9orf72 plays a cell-autonomous role in the regulation of neurotransmission at excitatory synapses by interaction with synapsin and modulation of synaptic vesicle pools, and identify a novel role for C9orf72 haploinsufficiency in synaptic dysfunction in C9ALS/FTD.

Apolipoprotein B-100-mediated motor neuron degeneration in sporadic amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis is a fatal neurodegenerative disease characterized by motor neuron degeneration. Approximately 90% of cases occur sporadically with no known cause while 10% are familial cases arising from known inherited genetic mutations. In vivo studies have predominantly utilized transgenic models harbouring amyotrophic lateral sclerosis-associated gene mutations, which have not hitherto elucidated mechanisms underlying motor neuron death or identified therapeutic targets specific to sporadic amyotrophic lateral sclerosis. Here we provide evidence demonstrating pathogenic differences in CSF from patients with sporadic amyotrophic lateral sclerosis and familial amyotrophic lateral sclerosis patients with mutations in SOD1, C9orf72 and TARDBP. Using a novel CSF-mediated animal model, we show that intrathecal delivery of sporadic amyotrophic lateral sclerosis patient-derived CSF into the cervical subarachnoid space in adult wild-type mice induces permanent motor disability which is associated with hallmark pathological features of amyotrophic lateral sclerosis including motor neuron loss, cytoplasmic TDP-43 translocation, reactive astrogliosis and microglial activation. Motor impairments are not induced by SOD1, C9orf72 or TARDBP CSF, although a moderate degree of histopathological change occurs in C9orf72 and TARDBP CSF-injected mice. By conducting a series of CSF filtration studies and global proteomic analysis of CSF, we identified apolipoprotein B-100 in sporadic amyotrophic lateral sclerosis CSF as the putative agent responsible for inducing motor disability, motor neuron degeneration and pathological translocation of TDP-43. Apolipoprotein B-100 alone is sufficient to recapitulate clinical and pathological outcomes in vivo and induce death of human induced pluripotent stem cell-derived motor neurons in vitro. Targeted removal of apolipoprotein B-100 from sporadic amyotrophic lateral sclerosis CSF via filtration or immunodepletion successfully attenuated the neurotoxic capacity of sporadic amyotrophic lateral sclerosis CSF to induce motor disability, motor neuron death, and TDP-43 translocation. This study presents apolipoprotein B-100 as a novel therapeutic target specific for the predominant sporadic form of amyotrophic lateral sclerosis and establishes proof-of-concept to support CSF pheresis as a therapeutic strategy for mitigating neurotoxicity in sporadic amyotrophic lateral sclerosis.

Old age amyotrophic lateral sclerosis and limbic TDP-43 pathology.

This study aimed to assess and compare the burden of transactive response DNA-binding protein of 43kDa (TDP-43) pathology and clinical features of amyotrophic lateral sclerosis (ALS) in three age groups. All cases were from the Mayo Clinic brain bank for neurodegenerative disorders and most were followed longitudinally in the ALS Clinic. Cases with moderate-to-severe Alzheimer's disease neuropathological change were excluded. The 55 cases included in the study were divided into three groups by age at death: 75 years or older (old-ALS, n=8), 64-74 years (middle-ALS, n=23), and 63 years or younger (young-ALS, n=24). Clinical features, including disease duration, initial symptoms, and ALS Cognitive Behavior Score (ALS-CBS), were summarized. Sections of paraffin-embedded tissue from the motor cortex, basal forebrain, medial temporal lobe, and middle frontal gyrus were processed for phospho-TDP-43 immunohistochemistry. The burden of TDP-43 pathology was analyzed using digital image analysis. The TDP-43 burden in the limbic system (i.e., amygdala, dentate gyrus and CA1 sector of the hippocampus, subiculum, and entorhinal cortex) was greater in old-ALS than in young-ALS and middle-ALS. TDP-43 burden in the middle frontal gyrus was sparse and did not differ between the three groups. The average of ALS-CBS was not different between the three groups. The present study shows that the amygdala and hippocampus are vulnerable to TDP-43 pathology in older patients with ALS. We discuss the evidence for and against this pathology being related to concurrent limbic-predominant, age-related TDP-43 encephalopathy neuropathologic change.

The diagnostic value of the Italian version of the Edinburgh Cognitive and Behavioral ALS Screen (ECAS)

Objectives: The diagnostic capabilities of specific cognitive screeners are clinically crucial for an early detection of frontotemporal features in amyotrophic lateral sclerosis (ALS) patients. This study aimed at providing diagnostic properties of the cognitive section of the Edinburgh Cognitive and Behavioral ALS Screen (ECAS) in Italian ALS patients. Methods: Eighty-nine consecutive Italian ALS patients were classified according to Strong et al. (2017) criteria with a comprehensive neuropsychological assessment. The Italian version of ECAS was also administered, and its accuracy, sensitivity (SE), specificity (SP), negative and positive predictive values (PPV; NPV) and likelihood ratios (LR+; LR-) were computed against clinical diagnoses. Results: The ECAS and its subscales yielded moderate-to-high accuracy (AUC = .7–.87). High SP was overall found (81.8%–100%). The most sensitive measures were ALS-specific and Executive (73.9–78.3%) subscales, while the least were the ALS-non-specific subscales (8.7–17.4%). ECAS measures showed good PPVs (60%–100%) and NPVs (75.9%–91.5%). Acceptable LRs were found (LR+: 6.97–4.3; LR–: .29–.91), with total and ALS-specific measures yielding the best estimates. Conclusions: This is the first study demonstrating the diagnostic value of the ECAS against a thorough neuropsychological assessment in Italy. ECAS-total and -ALS-specific scores are diagnostically sound as to both intrinsic and post-test features, whereas ALS-non-specific measures perform slightly worse.

Cerebellar pathology in motor neuron disease: neuroplasticity and neurodegeneration.

Amyotrophic lateral sclerosis is a relentlessly progressive multi-system condition. The clinical picture is dominated by upper and lower motor neuron degeneration, but extra-motor pathology is increasingly recognized, including cerebellar pathology. Post-mortem and neuroimaging studies primarily focus on the characterization of supratentorial disease, despite emerging evidence of cerebellar degeneration in amyotrophic lateral sclerosis. Cardinal clinical features of amyotrophic lateral sclerosis, such as dysarthria, dysphagia, cognitive and behavioral deficits, saccade abnormalities, gait impairment, respiratory weakness and pseudobulbar affect are likely to be exacerbated by co-existing cerebellar pathology. This review summarizes in vivo and post mortem evidence for cerebellar degeneration in amyotrophic lateral sclerosis. Structural imaging studies consistently capture cerebellar grey matter volume reductions, diffusivity studies readily detect both intra-cerebellar and cerebellar peduncle white matter alterations and functional imaging studies commonly report increased functional connectivity with supratentorial regions. Increased functional connectivity is commonly interpreted as evidence of neuroplasticity representing compensatory processes despite the lack of post-mortem validation. There is a scarcity of post-mortem studies focusing on cerebellar alterations, but these detect pTDP-43 in cerebellar nuclei. Cerebellar pathology is an overlooked facet of neurodegeneration in amyotrophic lateral sclerosis despite its contribution to a multitude of clinical symptoms, widespread connectivity to spinal and supratentorial regions and putative role in compensating for the degeneration of primary motor regions.

The split-elbow index: A biomarker of the split elbow sign in ALS

ObjectiveThe split elbow sign is a clinical feature of amyotrophic lateral sclerosis (ALS), characterised by preferential weakness of biceps brachii muscle compared to triceps. A novel neurophysiological index, termed the split elbow index (SEI), was developed to quantify the split-elbow sign, and assess its utility in ALS. MethodsClinical and neurophysiological assessment was prospectively undertaken on 34 ALS patients and 32 ALS mimics. Compound muscle action potential (CMAP) amplitude was recorded from biceps brachii and triceps muscles from which the SEI was calculated using the following formula:SEI=CMAPamplitudeBICEPSBRACHIICMAPamplitudeTRICEPSBRACHII ResultsThe split elbow sign was significantly more common in ALS patients when compared to ALS mimic patients (P < 0.05). The SEI was significantly reduced in ALS patients when compared to ALS mimics (P < 0.01). This reduction was evident in spinal and bulbar onset ALS. A SEI cut-off value of ≤0.62 exhibited a sensitivity of 71% and specificity of 61%. ConclusionsThe split elbow sign is significantly more common in ALS patients, and was supported by a reduction in the SEI. SignificanceThe SEI may be utilised as a surrogate biomarker of the split elbow sign in future ALS studies.

Non-motor features of amyotrophic lateral sclerosis: A clinic-based study

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder of motor neurons. Spread of pathology to other brain areas leads to development of non-motor symptoms (NMSs). These usually remain undiagnosed because of overwhelming motor problem and are responsible for significant distress to the patient. Our objective was to explore the burden of various NMSs of patients with ALS, compare between limb-onset and bulbar-onset patients, and to correlate with severity and duration of disease.

Clinically evident ocular movement abnormalities are specific for cognitive impairment in amyotrophic lateral sclerosis

Although oculomotor abnormalities (OMAs) are not usually considered prominent features of amyotrophic lateral sclerosis (ALS), they may represent potential clinical markers of neurodegeneration, especially when investigated together with cognitive and behavioral alterations. The aim of our study was to identify patterns of clinically evident OMAs in ALS patients and to correlate such findings with cognitive-behavioral data.

Tensor electrical impedance myography identifies clinically relevant features in amyotrophic lateral sclerosis

Objective. Electrical impedance myography (EIM) shows promise as an effective biomarker in amyotrophic lateral sclerosis (ALS). EIM applies multiple input frequencies to characterise muscle properties, often via multiple electrode configurations. Herein, we assess if non-negative tensor factorisation (NTF) can provide a framework for identifying clinically relevant features within a high dimensional EIM dataset. Approach. EIM data were recorded from the tongue of healthy and ALS diseased individuals. Resistivity and reactivity measurements were made for 14 frequencies, in three electrode configurations. This gives 84 (2 × 14 × 3) distinct data points per participant. NTF was applied to the dataset for dimensionality reduction, termed tensor EIM. Significance tests, symptom correlation and classification approaches were explored to compare NTF to using all raw data and feature selection. Main Results. Tensor EIM provides highly significant differentiation between healthy and ALS patients (p < 0.001, AUROC = 0.78). Similarly tensor EIM differentiates between mild and severe disease states (p < 0.001, AUROC = 0.75) and significantly correlates with symptoms (ρ = 0.7, p < 0.001). A trend of centre frequency shifting to the right was identified in diseased spectra, which is in line with the electrical changes expected following muscle atrophy. Significance. Tensor EIM provides clinically relevant metrics for identifying ALS-related muscle disease. This procedure has the advantage of using the whole spectral dataset, with reduced risk of overfitting. The process identifies spectral shapes specific to disease allowing for a deeper clinical interpretation.

Levosimendan for amyotrophic lateral sclerosis

Muscle weakness is the main characteristic of amyotrophic lateral sclerosis, which eventually leads to functional impairment and respiratory insufficiency. Progressive weakness derives from a loss of motor units and active muscle fibres. Striated muscle contraction depends on the interaction between intracellular calcium and the protein troponin. Troponin is made up of three subunits—troponin C is especially important for binding calcium and promoting a dynamic interplay between troponin and tropomyosin, with consequent muscle contraction.

Association of Clinically Evident Eye Movement Abnormalities With Motor and Cognitive Features in Patients With Motor Neuron Disorders.

Although oculomotor abnormalities (OMAs) are not usually considered prominent features of amyotrophic lateral sclerosis (ALS), they may represent potential clinical markers of neurodegeneration, especially when investigated together with cognitive and behavioral alterations. The aim of our study was to identify patterns of clinically evident OMAs in patients with ALS and to correlate such findings with cognitive-behavioral data. Three consecutive inpatient cohorts of Italian patients with ALS and controls were retrospectively evaluated to assess the frequency of OMAs and cognitive-behavioral alterations. The ALS population was divided into a discovery cohort and a replication cohort. Controls included a cohort of cognitively impaired individuals and patients with Alzheimer disease (AD). Participants underwent bedside eye movement evaluation to determine the presence and pattern of OMAs. Cognitive assessment was performed with a standard neuropsychological battery (discovery ALS cohort and AD cohort) and the Italian Edinburgh Cognitive and Behavioural ALS Screen (ECAS) (replication ALS cohort). We recruited 864 individuals with ALS (635 discovery, 229 replication), 798 who were cognitively unimpaired and 171 with AD. OMAs were detected in 10.5% of our ALS cohort vs 1.6% of cognitively unimpaired controls (p = 1.2 × 10-14) and 11.4% of patients with AD (p = NS). The most frequent deficits were smooth pursuit and saccadic abnormalities. OMA frequency was higher in patients with bulbar onset, prominent upper motor neuron signs, and advanced disease stages. Cognitive dysfunction was significantly more frequent in patients with OMAs in both ALS cohorts (p = 1.1 × 10-25). Furthermore, OMAs significantly correlated with the severity of cognitive impairment and with pathologic scores at the ECAS ALS-specific domains. Last, OMAs could be observed in 35.0% of cognitively impaired patients with ALS vs 11.4% of patients with AD (p = 6.4 × 10-7), suggesting a possible involvement of frontal oculomotor areas in ALS. Patients with ALS showed a range of clinically evident OMAs, and these alterations were significantly correlated with cognitive, but not behavioral, changes. OMAs may be a marker of neurodegeneration, and bedside assessment represents a rapid, highly specific tool for detecting cognitive impairment in ALS.

Clinical and epidemiological features of amyotrophic lateral sclerosis in eastern Turkey

Aim: The number of studies on the epidemiological and clinical data of amyotrophic lateral sclerosis (ALS) patients in Turkey is quite low and the studies on this subject reflect the data of western regions of Turkey. In this study, we aimed to present the demographic, clinical and mortality features of ALS patients diagnosed in the last 10 years in a large reference hospital in the Eastern Anatolia region of Turkey.&#x0D; Material and Method: 42 ALS patients diagnosed between January 2011 and January 2021 in ………., Faculty of Medicine, Department of Neurology were included in the study. The data of the patients were obtained by retrospectively scanning the patient electronic files registered in the database of our hospital. The age, gender, examination findings, clinical course, treatments they received and the cause of death of the patients were recorded.&#x0D; Results:26 of ALS patients were men and 16 were women. The mean age of onset was 53.4 ± 12.3 and the mean diagnostic delay was 13.6 ± 6.9 months. 64.2% of the patients had onset in the spinal region, and 35.7% in the bulbar region. Weakness/atrophy of the upper extremity muscles and swallowing difficulty were the most common onset symptoms. All ALS patients were using riluzole. 11 ALS patients died. The mean time between diagnosis and death in patients who died was 27.2 ± 18.6 months. The most common causes of death in ALS patients were pneumonia and sepsis.&#x0D; Conclusion: Age of onset of ALS was low in our patients. The number of patients in the clinically definite ALS group was the highest. Weakness/atrophy of the upper extremity muscles and swallowing difficulty were the most common onset symptoms. Approximately 2/3 of the patients had spinal, and 1/3 bulbar region onset. There was no significant difference between spinal and bulbar onset patients in terms of gender, age of disease onset, mortality, and life expectancy of patients with death. The rate of using riluzole was high. The most common causes of death in ALS patients were pneumonia and sepsis.

The pathogenic role of c-Kit+ mast cells in the spinal motor neuron-vascular niche in ALS

Degeneration of motor neurons, glial cell reactivity, and vascular alterations in the CNS are important neuropathological features of amyotrophic lateral sclerosis (ALS). Immune cells trafficking from the blood also infiltrate the affected CNS parenchyma and contribute to neuroinflammation. Mast cells (MCs) are hematopoietic-derived immune cells whose precursors differentiate upon migration into tissues. Upon activation, MCs undergo degranulation with the ability to increase vascular permeability, orchestrate neuroinflammation and modulate the neuroimmune response. However, the prevalence, pathological significance, and pharmacology of MCs in the CNS of ALS patients remain largely unknown. In autopsy ALS spinal cords, we identified for the first time that MCs express c-Kit together with chymase, tryptase, and Cox-2 and display granular or degranulating morphology, as compared with scarce MCs in control cords. In ALS, MCs were mainly found in the niche between spinal motor neuron somas and nearby microvascular elements, and they displayed remarkable pathological abnormalities. Similarly, MCs accumulated in the motor neuron-vascular niche of ALS murine models, in the vicinity of astrocytes and motor neurons expressing the c-Kit ligand stem cell factor (SCF), suggesting an SCF/c-Kit-dependent mechanism of MC differentiation from precursors. Mechanistically, we provide evidence that fully differentiated MCs in cell cultures can be generated from the murine ALS spinal cord tissue, further supporting the presence of c-Kit+ MC precursors. Moreover, intravenous administration of bone marrow-derived c-Kit+ MC precursors infiltrated the spinal cord in ALS mice but not in controls, consistent with aberrant trafficking through a defective microvasculature. Pharmacological inhibition of c-Kit with masitinib in ALS mice reduced the MC number and the influx of MC precursors from the periphery. Our results suggest a previously unknown pathogenic mechanism triggered by MCs in the ALS motor neuron-vascular niche that might be targeted pharmacologically.

Splicing factor proline and glutamine rich intron retention, reduced expression and aggregate formation are pathological features of amyotrophic lateral sclerosis.

Splicing factor proline and glutamine rich (SFPQ) is an RNA-DNA binding protein that is dysregulated in Alzheimer's disease and frontotemporal dementia. Dysregulation of SFPQ, specifically increased intron retention and nuclear depletion, has been linked to several genetic subtypes of amyotrophic lateral sclerosis (ALS), suggesting that SFPQ pathology may be a common feature of this heterogeneous disease. Our study aimed to investigate this hypothesis by providing the first comprehensive assessment of SFPQ pathology in large ALS case-control cohorts. We examined SFPQ at the RNA, protein and DNA levels. SFPQ RNA expression and intron retention were examined using RNA-sequencing and quantitative PCR. SFPQ protein expression was assessed by immunoblotting and immunofluorescent staining. At the DNA level, SFPQ was examined for genetic variation novel to ALS patients. At the RNA level, retention of SFPQ intron nine was significantly increased in ALS patients' motor cortex. In addition, SFPQ RNA expression was significantly reduced in the central nervous system, but not blood, of patients. At the protein level, neither nuclear depletion nor reduced expression of SFPQ was found to be a consistent feature of spinal motor neurons. However, SFPQ-positive ubiquitinated protein aggregates were observed in patients' spinal motor neurons. At the DNA level, our genetic screen identified two novel and two rare SFPQ sequence variants not previously reported in the literature. Our findings confirm dysregulation of SFPQ as a pathological feature of the central nervous system of ALS patients and indicate that investigation of the functional consequences of this pathology will provide insight into ALS biology.

Amyotrophic lateral sclerosis features predict TDP-43 pathology in frontotemporal lobar degeneration

Clinical and pathological heterogeneity is common in patients with frontotemporal lobar degeneration (FTLD) pathology. This investigated clinical or imaging characteristics that differentiate FTLD-TDP from FTLD-tau, FTLD-TDP subtypes from each other, or pathological stages of FTLD-TDP. Initial clinical, neuropsychological and neuroimaging characteristics were compared between pathologically defined FTLD-tau and FTLD-TDP groups. Voxel-based morphometry analyses contrasted grey matter atrophy patterns. Twenty-six FTLD-TDP, 28 FTLD-tau and 78 controls were included. Amyotrophic lateral sclerosis features, when present, were highly specific FTLD-TDP, which displayed greater cortical and subcortical atrophy than FTLD-tau. FTLD-TDP-43 type B had significantly shorter survival than type A. Type A patients were more cognitively impaired than type B, and basal ganglia atrophy appeared to distinguish type A from type B. Age at onset and survival duration were comparable between stages II and IV. In conclusion, Amyotrophic lateral sclerosis features may be useful in distinguishing FTLD-TDP from FTLD-tau. TDP-43 type A and B appear to present with distinct profiles. The relationship between clinical features and pathological staging in FTLD-TDP-43 is complex, and TDP-43 subtyping may have more clinical utility.

SY1.2. The diagnostic utility of threshold tracking TMS in ALS

Concomitant dysfunction of upper (UMN) and lower motor (LMN) neurons is the pathognomonic feature of amyotrophic lateral sclerosis (ALS). The relationship between upper and lower motor neuron dysfunction in ALS remains to be elucidated, although it has been proposed that the disease origin lies within the central nervous system, with subsequent LMN degeneration progressing via an anterograde glutamatergic excitotoxic mechanism. Transcranial magnetic stimulation (TMS) is a neurophysiological tool that provides a non- invasive and painless assessment of cortical function. Recently, threshold tracking methodologies have been adopted for TMS, whereby changes in threshold rather than motor evoked potential (MEP) amplitude serve as outcome measures, leading to the development of a more reliable and quicker tool for assessing cortical function in ALS. Importantly, this threshold tracking TMS technique has established that cortical hyperexcitability is an early feature in sporadic ALS that precedes the onset of LMN dysfunction and mediates the pattern of disease spread. Separately, cortical hyperexcitability was reported to precede the clinical onset of familial ALS phenotypes. Of further relevance, the threshold tracking TMS technique was proven to reliably distinguish ALS from mimicking disorders, even in the presence of a comparable degree of LMN dysfunction, suggesting the diagnostic utility of TMS. Taken in total, threshold tracking TMS has provided support for a central origin of ALS, underscoring the utility of the technique for probing the underlying pathophysiology. This presentation will discuss the physiological processes underlying threshold tracking TMS, while further evaluating the pathophysiological and diagnostic utility of threshold tracking TMS in ALS.

P-NU002. Muscle ultrasound is a highly sensitive non-invasive tool to detect fasciculations in limbs, tongue and paraspinal muscles in amyotrophic lateral sclerosis

Introduction . Fasciculations are characteristic feature of Amyotrophic Lateral Sclerosis (ALS) and their identification by Muscle Ultrasound (MUS) is an important non-invasive tool and allows studying the major bulk and more inaccessible muscles. This could potentially replace painful Electromyography (EMG) procedure to identify fasciculations. Our aim is to utilize MUS to identify and also detect fasciculations in unaffected muscles in early stages of ALS and correlate with EMG findings. Methods . In 30 cases (7 bulbar and 23 limb onset) with suspected ALS, we performed EMG in 3 muscles (biceps brachii, quadriceps and thoracic paraspinal) and MUS in 9 muscles (biceps, triceps, deltoid, abductor digiti minimi, quadriceps, hamstrings, tibialis anterior, thoracic paraspinal and tongue). MUS was performed using linear transducer (3-13 MHz, Esaote Mylab Gamma Scanner). Fasciculations were observed in each muscle for one minute. Frequency of fasciculations detected by MUS was compared with EMG findings in same muscles. Results . The M:F ratio was 4:1, age of onset was 50.1±12.8 years, age of presentation was 50.9±12.9 years. Duration of illness was 1.21±1.08 years. Of the total muscles studied, 176 muscles showed wasting while 334 were normal. Out of 284 muscles without clinical fasciculations, 206 (72.5%) showed fasciculations on MUS. Of 90 muscles examined by EMG, 20 (40.8%) of 49 muscles without clinical fasciculations showed fasciculations. Out of 23 pure limb onset cases, 16 cases showed extrinsic tongue muscle fasciculations on MUS. Fasciculations as detected by MUS vs. EMG: biceps brachii (90% vs 76.6%), quadriceps (80% vs 50%) and thoracic paraspinal (66.6% vs 40%) Conclusion . MUS is a promising tool in diagnosis of ALS. MUS is more sensitive in detecting fasciculations compared to EMG, can substitute it as it is noninvasive, safer, easily accessible, can access larger muscle areas in shorter examination time. Further, the test can be repeated for any longitudinal/sequential assessments.

A pilot study of the breath stacking technique associated with respiratory muscle endurance training in patients with amyotrophic lateral sclerosis: videofluoroscopic findings in the upper airway.

Bulbar impairment represents a hallmark feature of amyotrophic lateral sclerosis (ALS) that significantly impacts survival and quality of life. Respiratory complications arise because of the weakness of the upper airway and respiratory muscles leading to respiratory failure, impaired swallowing, and reduced airway safety. Breath stacking and respiratory muscle endurance training are techniques that have been described to improve respiratory and bulbar function in patients with ALS. Considering the above, a respiratory technique named TR3 was developed. This study aimed to measure the acute effects of this technique on the upper airway through videofluoroscopy and to assess its clinical trial feasibility in patients with ALS. In this cross-sectional study, we enrolled participants diagnosed with ALS to perform a single session of TR3. Epidemiological data and baseline assessments were collected. The assessments included kinematics from videofluoroscopy measuring the retropalatal airspace size, the size of the narrowest airway, and the pharyngeal area during rest and TR3. Eight participants were included. During TR3, an acute increase of 15% was observed in the retropalatal airspace size (t = 5.14, p < 0.01), a 123% increase was observed in the size of the narrowest airway (t = -4.18, p < 0.001), and a 277% increase was observed in the pharyngeal area (t = -5.34, p < 0.001). During the intervention, TR3 showed acute effects in increasing pharyngeal constriction, pharyngeal expansion, retropalatal airspace size, and post-lingual narrowest airway size and is feasible for a larger research program. A clinical trial (NCT04226144) is already being conducted to assess the chronic therapeutic effects of this technique and its impact on the clinical evolution of ALS.

Trends in the clinical features of amyotrophic lateral sclerosis: A 14-year Chinese cohort study.

The aim was to determine the transitional patterns in the clinical characteristics, treatments and comorbidities in amyotrophic lateral sclerosis (ALS) patients over the past 14years using data from a large clinical cohort in mainland China. Sporadic ALS patients who visited the Peking University Third Hospital from January 2005 to December 2018 were included in this study. The 14years were divided into three periods, and changes in the baseline characteristics of the participants were analyzed at 5-year intervals. In total, 3410 patients with sporadic ALS were recruited: 2181 were men and 1229 were women. The proportion of patients with bulbar-onset ALS increased from 13.0% in 2005-2009 to 19.5% in 2015-2018 (p<0.001). The mean (standard deviation) age at onset increased from 49.5 (11.4) years in 2005-2009 to 53.0 (11.0) years in 2015-2018 (p<0.001). ALS patients with diabetes or hypertension showed a delay in ALS onset, and the delay was even more apparent when the patients had both comorbidities. The proportion of riluzole users in 2015-2018 was approximately 2.5-fold of that in 2005-2009 (p<0.001). In the context of a lack of clinical data on ALS in mainland China, this study evaluated a large cohort of patients diagnosed over a 14-year period. The age at onset and percentage of patients who used riluzole both increased over the study period. Additionally, it was found that patients with comorbidities such as diabetes and hypertension had a delayed age of ALS onset.