Clinical and genetic factors affecting diagnostic timeline of amyotrophic lateral sclerosis: a 15-year retrospective study.

OBJECTIVES: Amyotrophic Lateral Sclerosis (ALS) diagnosis can take 10-16 months from symptom onset, leading to delays in treatment and patient counselling. We studied the impact of clinical and genetic risk factors on the diagnostic timeline of ALS. METHODS: Baseline characteristics, family history, gene testing, onset location, time from symptom onset to diagnosis, and time from first doctor visit to suspected ALS was collected. We used multiple regression to assess the interaction of these factors on ALS diagnostic timeline. We analysed a subgroup of patients with genetic testing and compared positive or negative tests, sporadic or familial and ALS-related genes to time for diagnosis. RESULTS: Four hundred and forty-eight patients diagnosed with ALS at the University of Massachusetts Chan Medical Center between January 2007 and December 2021 were analysed. The median time to ALS diagnosis was 12 months and remained unchanged from 2007 to 2021 (p = 0.20). Diagnosis was delayed in patients with sporadic compared with familial ALS (mean months [standard deviation], 16.5[13.5] and 11.2[8.5], p < 0.001); cognitive onset (41[21.26]) had longer time to diagnosis than bulbar (11.9[8.2]), limb (15.9[13.2]), respiratory (19.7[13.9]) and ALS with multiple onset locations (20.77[15.71], p < 0.001). One hundred and thirty-four patients had gene testing and 32 tested positive (23.8%). Gene testing (p = 0.23), a positive genetic test (p = 0.16), different ALS genes (p = 0.25) and sporadic (p = 0.92) or familial (p = 0.85) ALS testing positive for ALS genes did not influence time to diagnosis. DISCUSSION: Time for ALS diagnosis remained unchanged from 2007 to 2021, bulbar-onset and familial ALS made for faster diagnosis.

Reversible cerebral vasoconstriction syndrome and posterior reversible encephalopathy syndrome following vaccination: analysis of the VAERS database and systematic review.

Objectives: This study aimed to analyze the Vaccine Adverse Event Reporting System (VAERS) database and systematically review the literature to provide a comprehensive analysis of reversible cerebral vasoconstriction syndrome (RCVS) and posterior reversible encephalopathy syndrome (PRES) secondary to vaccination. Methods: The authors analyzed the VAERS database and conducted a systematic review following PRISMA guidelines. The inclusion criteria for VAERS data were a score of ≥3 on the RCVS2 score and/or radiographic findings consistent with the diagnosis of RCVS or PRES. The systematic review was registered with PROSPERO. Results: Our combined data set included 29 cases (9 RCVS and 20 PRES). Most cases were women (72.4%) with a mean age of 50.7 years (SD 19.4 years). Most cases were associated with COVID-19 mRNA vaccines (58.6% Moderna, 20.7% Pfizer). Hypertension (37.9%), hyperlipidemia (13.7%), chronic kidney disease (CKD) (10.3%), and end-stage renal disease (6.8%) were common comorbidities. Furthermore, 20.6% (6/29) of cases were on immunosuppression therapy for various reasons. The mean time to symptom onset was 10.49 days after vaccination (SD 18.60), and the mean duration of hospitalization was 7.42 days (SD 5.94). The symptoms reported the most frequently were headache (41.3%), elevated blood pressure (31.0%), and emesis (17.2%). Typical radiographic findings included T2/FLAIR hyperintensities affecting the parieto-occipital lobes, indicative of vasogenic and/or cytotoxic edema. Conclusions: This study provides a comprehensive analysis of postvaccine RCVS and PRES. Both disease states were seen most often in those with pre-existing risk factors such as female sex, age over 50, hypertension, renal disease, and immunosuppression. Vaccines and their associated immune response may cause endothelial dysfunction leading to cerebral vasospasm and loss of cerebral autoregulation. However, further research is required to understand the underlying pathophysiological mechanisms. Despite the associations found, the absolute risk of these syndromes remains extremely low compared to the immense benefits of vaccination.

Cyclonite-Induced Seizures After Voluntary C-4 Ingestion.

Cyclonite (cyclotrimethylenetrinitramine, RDX, hexogen) is the active agent in the plastic explosive, composition 4 (C-4). It has been used globally since the Vietnam War for both military and civilian applications due to its metastable nature. Ingestion or inhalation of C-4 can cause euphoric effects such as those commonly seen with alcohol toxicity, in addition to seizures and rarely fulminant liver and kidney failure. We report the case of a patient who ingested 75 g of C-4 and presented with a generalized tonic-clonic seizure four hours after ingestion. Our patient made a full recovery after being stabilized with temporizing anticonvulsants in the intensive care unit.

Successful Mechanical Thrombectomy of Bilateral Middle Cerebral Artery Occlusions Following Apixaban Discontinuation.

Optimal anticoagulation management in patients with atrial fibrillation (AF) during acute ischemic stroke is complex and often poses a significant clinical challenge. An 82-year-old man with AF presented with left-sided hemiparesis and hypoesthesia due to occlusion of the right middle cerebral artery (MCA) after discontinuing apixaban for 5 days. Successful mechanical thrombectomy (MT) achieved thrombolysis in cerebral infarction (TICI) score of 2C. Anticoagulation was postponed due to a small risk of hemorrhagic conversion. However, the patient developed a rare bilateral M1 segment MCA occlusions on the fifth day with a National Institute of Health Stroke Scale (NIHSS) score of 23, leading to an emergent thrombectomy, resulting in TICI 3 and TICI 2C recanalization in left and right MCAs, respectively. The patient required admission to the intensive care unit and was eventually discharged to an inpatient rehabilitation facility with only residual left hemiparesis and moderate dysarthria. This case underscores the delicate balance between the risk of recurrent ischemic stroke and the potential for hemorrhagic conversion when treating anticoagulation in the acute setting. Close monitoring and an individualized approach are necessary for the treatment of patients with AF who have suffered an acute stroke, especially when anticoagulation must be stopped. We encourage future guidelines to incorporate both imaging and clinical data when determining the continuation of anticoagulation in patients with a recent ischemic stroke. This case also depicts the effectiveness of neuroendovascular interventions such as MT to effectively manage rare simultaneous large multi-vessel occlusions with good outcomes.

Characteristics and outcomes of postpartum cerebral venous sinus thrombosis: A subgroup analysis of the ACTION-CVT study.

BACKGROUND AND PURPOSE: There is a relative paucity of data regarding long-term outcomes and treatment-related complications in women of childbearing age with cerebral venous sinus thrombosis (CVST). We sought to determine whether outcomes differ in women of childbearing age with versus without postpartum CVST. METHODS: We retrospectively analysed 373 non-pregnant females of childbearing age (18-45 years) included in the multicenter observational Anticoagulation in the Treatment of Cerebral Venous Thrombosis study (ACTION-CVT). Comparisons were made between postpartum (first 12 weeks from delivery, n=38 [10.2%]) versus non-postpartum women (n=335 [89.8%]). The primary outcomes of interest were one-year risk of all-cause death, venous thromboembolism (VTE) recurrence, and major hemorrhage (i.e., new or worsening intracranial hemorrhage or major extracranial hemorrhage). Secondary outcomes were the discharge disposition and modified Rankin Scale (mRS) score at discharge and 90 days. RESULTS: Postpartum status was associated with greater risk of seizures (42.1% versus 20.9%, p=0.003), venous infarction (47.4% versus 29.5%, p=0.025), intracranial hemorrhage (55.3% versus 36.1%, p=0.022), and requirement for neurosurgical treatment (13.2% versus 3.6%, p=0.021). There was no significant association with one year all cause death (N=373 HR=1.35, 95%-CI=0.15-11.87, p=0.784), VTE recurrence (N=373, HR=1.27, 95%-CI=0.45-3.59, p=0.648), major hemorrhage (N=373, HR=1.36, 95%-CI=0.46-4.0, p=0.581) as well as excellent (mRS[0-1]: OR=1.58, 95%-CI=0.4-7.1, p=0.554) and good (mRS[0-2]: OR=0.92, 95%-CI=0.2-4.27, p=0.918) 90-day mRS. Results were similar after adjustment for potential confounders. CONCLUSIONS: Although CVST in the 12-week postpartum period was more frequently associated with early complications, 90-day functional disability and one-year outcomes were similar to women with CVST unrelated to pregnancy.

Pharmacotherapy for Amyotrophic Lateral Sclerosis: A Review of Approved and Upcoming Agents.

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disorder involving loss of upper and lower motor neurons, with most cases ending in death within 3-5 years of onset. Several molecular and cellular pathways have been identified to cause ALS; however, treatments to stop or reverse disease progression are yet to be found. Riluzole, a neuroprotective agent offering only a modest survival benefit, has long been the sole disease-modifying therapy for ALS. Edaravone, which demonstrated statistically significant slowing of ALS disease progression, is gaining approval in an increasing number of countries since its first approval in 2015. Sodium phenylbutyrate and taurursodiol (PB-TURSO) was conditionally approved in Canada in 2022, having shown significant slowing of disease progression and prolonged survival. Most clinical trials have focused on testing small molecules affecting common cellular pathways in ALS: targeting glutamatergic, apoptotic, inflammatory, and oxidative stress mechanisms among others. More recently, clinical trials utilizing stem cell transplantation and other biologics have emerged. This rich and ever-growing pipeline of investigational products, along with innovative clinical trial designs, collaborative trial networks, and an engaged ALS community', provide renewed hope to finding a cure for ALS. This article reviews existing ALS therapies and the current clinical drug development pipeline.

Gene Therapy in Amyotrophic Lateral Sclerosis.

Since the discovery of Cu/Zn superoxide dismutase (SOD1) gene mutation, in 1993, as the first genetic abnormality in amyotrophic lateral sclerosis (ALS), over 50 genes have been identified as either cause or modifier in ALS and ALS/frontotemporal dementia (FTD) spectrum disease. Mutations in C9orf72, SOD1, TAR DNA binding protein 43 (TARDBP), and fused in sarcoma (FUS) genes are the four most common ones. During the last three decades, tremendous effort has been made worldwide to reveal biological pathways underlying the pathogenesis of these gene mutations in ALS/FTD. Accordingly, targeting etiologic genes (i.e., gene therapies) to suppress their toxic effects have been investigated widely. It includes four major strategies: (i) removal or inhibition of abnormal transcribed RNA using microRNA or antisense oligonucleotides (ASOs), (ii) degradation of abnormal mRNA using RNA interference (RNAi), (iii) decrease or inhibition of mutant proteins (e.g., using antibodies against misfolded proteins), and (iv) DNA genome editing with methods such as clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (CRISPR/Cas). The promising results of these studies have led to the application of some of these strategies into ALS clinical trials, especially for C9orf72 and SOD1. In this paper, we will overview advances in gene therapy in ALS/FTD, focusing on C9orf72, SOD1, TARDBP, and FUS genes.

Intuitive Staging Correlates With King's Clinical Stage.

Background: Clinical stage in amyotrophic lateral sclerosis (ALS) can be assigned using King's staging with a simple protocol based on the number of CNS regions involved and the presence of significant nutritional or respiratory failure. It is important that the assigned clinical stage matches expectations, and generally corresponds with how a health care professional would intuitively stage the patient. We therefore investigated the relationship between King's clinical ALS stage and ALS stage as intuitively assigned by health care professionals. Methods: We wrote 17 case vignettes describing people with ALS at different disease stages from very early limited disease involvement through to severe, multi-domain disease. During two workshops, we asked health care professionals to intuitively stage the vignettes and compared the answers with the actual King's clinical ALS stage. Results: There was a good correlation between King's clinical ALS stage and intuitively assigned stage, with a Spearman's Rank correlation coefficient of 0.64 (p < 0.001). There was no difference in the intuitive stages assigned by practitioners of different types or at different levels of experience. Conclusions: Across a spectrum of ALS scenarios, King's clinical ALS stage corresponds to intuitive ALS stage as assigned by a range of health care professionals.

Patient reported outcome measures (PROMs) in amyotrophic lateral sclerosis.

OBJECTIVE: Patient reported outcome measures (PROMs) can provide researchers with a direct view of patients' experiences. They are becoming increasingly important tools for evaluating clinical care and research outcomes. There has been little data on the application of PROMs to amyotrophic lateral sclerosis (ALS) care. The objective of this study was to examine the feasibility of PROM collection in an academic ALS clinic and to measure correlations between PROMs and standard ALS clinical outcome measures. METHODS: PROMs were gathered from tablet-based surveys offered to adult patients in the waiting room, prior to ALS outpatient clinic visits. They included a demographic section and two validated surveys: the patient reported outcome measurement information system (PROMIS-10), which generates physical health and mental health subscores, and the quality of life in neurological disorders-fatigue subscale (NeuroQoL-fatigue). The ALS functional rating scale-revised (ALSFRS-R) and other ALS measures were collected by clinic staff as part of routine clinical care. RESULTS: PROMIS-10 physical and mental health scores correlated positively with the ALSFRS-R score (physical: R = 0.85, p < 0.001; mental: R = 0.58, p = 0.02). NeuroQoL-fatigue scores were inversely correlated with the ALSFRS-R scores-higher fatigue correlated with lower function (R = - 0.72, p = 0.004). CONCLUSION: Collection of PROMs is feasible in the context of routine ALS care. PROM scores are highly correlated with validated ALS outcome measures.

Multi-input Synapses, but Not LTP-Strengthened Synapses, Correlate with Hippocampal Memory Storage in Aged Mice.

Long-lasting changes at synapses enable memory storage in the brain. Although aging is associated with impaired memory formation, it is not known whether the synaptic underpinnings of memory storage differ with age. Using a training schedule that results in the same behavioral memory formation in young and aged mice, we examined synapse ultrastructure and molecular signaling in the hippocampus after contextual fear conditioning. Only in young, but not old mice, contextual fear memory formation was associated with synaptic changes that characterize well-known, long-term potentiation, a strengthening of existing synapses with one input. Instead, old-age memory was correlated with generation of multi-innervated dendritic spines (MISs), which are predominantly two-input synapses formed by the attraction of an additional excitatory, presynaptic terminal onto an existing synapse. Accordingly, a blocker used to inhibit MIS generation impaired contextual fear memory only in old mice. Our results reveal how the synaptic basis of hippocampal memory storage changes with age and suggest that these distinct memory-storing mechanisms may explain impaired updating in old age.

Telomere length is greater in ALS than in controls: a whole genome sequencing study.

Background: Amyotrophic lateral sclerosis is a neurodegenerative disease of motor neurons resulting in progressive paralysis and death, typically within 3-5 years. Although the heritability of ALS is about 60%, only about 11% is explained by common gene variants, suggesting that other forms of genetic variation are important. Telomeres maintain DNA integrity during cellular replication and shorten naturally with age. Gender and age are risk factors for ALS and also associated with telomere length. We therefore investigated telomere length in ALS. Methods: We estimated telomere length by applying a bioinformatics analysis to whole genome sequence data of leukocyte-derived DNA from people with ALS and age and gender-matched matched controls in a UK population. We tested the association of telomere length with ALS and ALS survival. Results: There were 1241 people with ALS and 335 controls. The median age for ALS was 62.5 years and for controls, 60.1 years, with a male-female ratio of 62:38. Accounting for age and sex, there was a 9% increase of telomere length in ALS compared to matched controls. Those with longer telomeres had a 16% increase in median survival. Of nine SNPs associated with telomere length, two were also associated with ALS: rs8105767 near the ZNF208 gene (p = 1.29 × 10-4) and rs6772228 (p = 0.001), which is in an intron for the PXK gene. Conclusions: Longer telomeres in leukocyte-derived DNA are associated with ALS, and with increased survival in those with ALS.

A standard operating procedure for King's ALS clinical staging.

Objective: Clinical stages in amyotrophic lateral sclerosis (ALS) can be measured using a simple system based on the number of CNS regions involved and requirement for gastrostomy or noninvasive ventilation (NIV). We aimed to design a standard operating procedure (SOP) to define the standardized use and application of the King's staging system. Methods: We designed a SOP for the King's staging system. We wrote case vignettes representative of ALS patients at different disease stages. During two workshops, we taught health care professionals how to use the SOP, then asked them to stage the vignettes using the SOP. We measured the extent to which SOP staging corresponded with correct clinical stage. Results: The reliability of staging using the SOP was excellent, with a Spearman's Rank coefficient of 0.95 (p < 0.001), and was high for different groups of health care professionals, and for those with different levels of experience in ALS. The limits of agreement between SOP staging and actual clinical stage lie within a single stage, confirming that there is a clinically acceptable level of agreement between staging using the SOP and actual King's clinical stage. There were also no systematic biases of the SOP over the range of stages, either for over-staging or under-staging. Conclusions: We have demonstrated that the staging SOP provides a reliable method of calculating clinical stages in ALS patients and can be used prospectively by a range of health care professionals with different levels of experience, as for example may be the case in multicentre clinical trials.

Stage at which riluzole treatment prolongs survival in patients with amyotrophic lateral sclerosis: a retrospective analysis of data from a dose-ranging study.

BACKGROUND: Riluzole is the only drug to prolong survival for amyotrophic lateral sclerosis (ALS) and, at a dose of 100 mg, was associated with a 35% reduction in mortality in a clinical trial. A key question is whether the survival benefit occurs at an early stage of disease, late stage, or is spread throughout the course of the disease. To address this question, we used the King's clinical staging system to do a retrospective analysis of data from the original dose-ranging clinical trial of riluzole. METHODS: In the original dose-ranging trial, patients were enrolled between December, 1992, and November, 1993, in Belgium, France, Germany, Spain, Canada, the USA, and the UK if they had probable or definite ALS as defined by the El Escorial criteria. The censor date for the riluzole survival data was set as the original study end date of Dec 31, 1994. For this analysis, King's clinical ALS stage was estimated from the electronic case record data of the modified Norris scale, UK Medical Research Council score for muscle strength, El Escorial category, vital capacity, and gastrostomy insertion data. The lowest allocated stage was 2 because the original trial only included patients with probable or definite ALS. We used a χ2 test to assess the independence of stage at trial enrolment and treatment group, Kaplan-Meier product limit distribution to test the transition from each stage to subsequent stages, and Cox regression to confirm an effect of treatment group on time in stage, controlling for covariates. We did sensitivity analyses by combining treatment groups, using alternative strategies to stage, stratifying by stage at trial enrolment, and using multistate outcome analysis of treatments (MOAT). FINDINGS: We analysed the case records of all 959 participants from the original dose-ranging trial, 237 assigned to 50 mg/day riluzole, 236 to 100 mg/day, 244 to 200 mg/day, and 242 to daily placebo. Clinical stage at enrolment did not significantly differ between treatment groups (p=0·22). Time in stage 4 was longer for patients receiving 100 mg/day riluzole than for those receiving placebo (hazard ratio [HR] 0·55, 95% CI 0·36-0·83; log-rank p=0·037). Combining treatment groups and stratifying by stage at enrolment showed a similar result (HR 0·638, 95% CI 0·464-0·878; p=0·006), as did analysis with MOAT where the mean number of days spent in stage 4 was numerically higher for patients given riluzole at higher doses compared with patients receiving placebo. Time from stages 2 or 3 to subsequent stages or death did not differ between riluzole treatment groups and placebo (p=0·83 for stage 2 and 0·88 for stage 3). INTERPRETATION: We showed that riluzole prolongs survival in the last clinical stage of ALS; this finding needs to be confirmed in a prospective study, and treatment effects at stage 1 still need to be analysed. The ALS stage at which benefit occurs is important for counselling of patients before starting treatment. Staging should be used in future ALS clinical trials to assess the stage at which survival benefit occurs, and a similar approach could be used for other neurodegenerative diseases. FUNDING: NIHR Maudsley Biomedical Research Centre, The European Union Joint Programme on Neurodegeneration, and the King's Summer Undergraduate Studentship.

Systematic review of the efficacy of non-pharmacological interventions in people with Lewy body dementia.

ABSTRACTBackground:Pharmacological interventions for Lewy body dementia (LBD), especially for its non-cognitive symptoms, are limited in their efficacy and tolerability. Clinicians are often uncertain about non-pharmacological interventions and their efficacy in managing cognitive and non-cognitive symptoms of LBD. Therefore, we aimed to systematically review the existing literature on non-pharmacological interventions for people with LBD. METHODS: We carried out a systematic search using six databases. All human studies examining impact of any non-pharmacological intervention on LBD were assessed for cognitive, physical, psychiatric, and quality-of-life outcomes. Study quality was assessed by Effective Public Health Practice Project Quality Assessment Tool for Quantitative Studies and the CARE criteria checklist. RESULTS: Prevailing evidence supporting the efficacy of non-pharmacological interventions is weak. We screened 1,647 papers. Fifteen studies (n = 61) including 11 case reports were found eligible for this systematic review. Interventions and reported outcomes were heterogeneous. Deep brain stimulation of the nucleus basalis of Meynert reportedly conferred cognitive benefit. Electroconvulsive therapy and repetitive transcranial magnetic stimulation have been reported to ameliorate depressive symptoms. Transcranial direct current stimulation was observed to improve attention. Exercise-based interventions reportedly improve various clinically important outcomes. Spaced retrieval memory training and environmental intervention for "mirror sign" have also been reported. CONCLUSIONS: Several non-pharmacological interventions have been studied in LBD. Although evidence supporting their efficacy is not robust, prevailing preliminary evidence and limitations of available pharmacological interventions indicate the need to consider appropriate non-pharmacological interventions, while planning comprehensive care of LBD patients. Larger trials evaluating the efficacy of non-pharmacological interventions for LBD are needed.

Nonmotor Symptoms in Amyotrophic Lateral Sclerosis: A Systematic Review.

BACKGROUND: ALS is a progressive neurodegenerative disease with no curative treatment. Nonmotor symptoms presenting in ALS may cause significant distress, worsen prognosis, and affect survival. OBJECTIVE: To systematically review evidence for the prevalence of nonmotor ALS symptoms, and treatment options. METHODS: Multiple medical literature databases were searched and studies screened using predefined inclusion criteria. Of 4580 studies, 44 were eligible for inclusion with 25 relating to treatment and 19 to the prevalence of nonmotor symptoms in ALS. RESULTS: Nonmotor symptoms involve neuropsychiatric, autonomic, gastrointestinal, and vascular systems, and affect between 5% and 80% of people with ALS. Screening tools for individual nonmotor symptoms are useful in classifying symptom severity and to compare between treatment options. Several methods to relieve nonmotor symptoms have been trialed with varying success rates. CONCLUSIONS: Many of the current studies of nonmotor symptoms in ALS have small sample sizes, requiring more evidence to increase precision in prevalence estimates. Further research is needed to assess the efficacy of current treatments and to find new therapies. Symptom relief or treatment of these nonmotor symptoms should therefore be considered during the clinical management of ALS.

Age-dependent changes in autophosphorylation of alpha calcium/calmodulin dependent kinase II in hippocampus and amygdala after contextual fear conditioning.

The hippocampus and amygdala are essential brain regions responsible for contextual fear conditioning (CFC). The autophosphorylation of alpha calcium-calmodulin kinase II (αCaMKII) at threonine-286 (T286) is a critical step implicated in long-term potentiation (LTP), learning and memory. However, the changes in αCaMKII levels with aging and training in associated brain regions are not fully understood. Here, we studied how aging and training affect the levels of phosphorylated (T286) and proportion of phosphorylated:total αCaMKII in the hippocampus and amygdala. Young and aged mice, naïve (untrained) and trained in CFC, were analysed by immunohistochemistry for the levels of total and phosphorylated αCaMKII in the hippocampus and amygdala. We found that two hours after CFC training, young mice exhibited a higher level of phosphorylated and increased ratio of phosphorylated:total αCaMKII in hippocampal CA3 stratum radiatum. Furthermore, aged untrained mice showed a higher ratio of phosphorylated:total αCaMKII in the CA3 region of the hippocampus when compared to the young untrained group. No effect of training or aging were seen in the central, lateral and basolateral amygdala regions, for both phosphorylated and ratio of phosphorylated:total αCaMKII. These results show that aging impairs the training-induced upregulation of autophosphorylated (T286) αCaMKII in the CA3 stratum radiatum of the hippocampus. This indicates that distinct age-related mechanisms underlie CFC that may rely more heavily on NMDA receptor-dependent plasticity in young age.

Comparison of the King's and MiToS staging systems for ALS.

OBJECTIVE: To investigate and compare two ALS staging systems, King's clinical staging and Milano-Torino (MiToS) functional staging, using data from the LiCALS phase III clinical trial (EudraCT 2008-006891-31). METHODS: Disease stage was derived retrospectively for each system from the ALS Functional Rating Scale-Revised subscores using standard methods. The two staging methods were then compared for timing of stages using box plots, correspondence using chi-square tests, agreement using a linearly weighted kappa coefficient and concordance using Spearman's rank correlation. RESULTS: For both systems, progressively higher stages occurred at progressively later proportions of the disease course, but the distribution differed between the two methods. King's stage 3 corresponded to MiToS stage 1 most frequently, with earlier King's stages 1 and 2 largely corresponding to MiToS stage 0 or 1. The Spearman correlation was 0.54. There was fair agreement between the two systems with kappa coefficient of 0.21. CONCLUSION: The distribution of timings shows that the two systems are complementary, with King's staging showing greatest resolution in early to mid-disease corresponding to clinical or disease burden, and MiToS staging having higher resolution for late disease, corresponding to functional involvement. We therefore propose using both staging systems when describing ALS.