Genotypes and phenotypes of motor neuron disease: an update of the genetic landscape in Scotland.

BACKGROUND: Using the Clinical Audit Research and Evaluation of Motor Neuron Disease (CARE-MND) database and the Scottish Regenerative Neurology Tissue Bank, we aimed to outline the genetic epidemiology and phenotypes of an incident cohort of people with MND (pwMND) to gain a realistic impression of the genetic landscape and genotype-phenotype associations. METHODS: Phenotypic markers were identified from the CARE-MND platform. Sequence analysis of 48 genes was undertaken. Variants were classified using a structured evidence-based approach. Samples were also tested for C9orf72 hexanucleotide expansions using repeat-prime PCR methodology. RESULTS: 339 pwMND donated a DNA sample: 44 (13.0%) fulfilled criteria for having a pathogenic variant/repeat expansion, 53.5% of those with a family history of MND and 9.3% of those without. The majority (30 (8.8%)) had a pathogenic C9orf72 repeat expansion, including two with intermediate expansions. Having a C9orf72 expansion was associated with a significantly lower Edinburgh Cognitive and Behavioural ALS Screen ALS-Specific score (p = 0.0005). The known pathogenic SOD1 variant p.(Ile114Thr), frequently observed in the Scottish population, was detected in 9 (2.7%) of total cases but in 17.9% of familial cases. Rare variants were detected in FUS and NEK1. One individual carried both a C9orf72 expansion and SOD1 variant. CONCLUSIONS: Our results provide an accurate summary of MND demographics and genetic epidemiology. We recommend early genetic testing of people with cognitive impairment to ensure that C9orf72 carriers are given the best opportunity for informed treatment planning. Scotland is enriched for the SOD1 p.(Ile114Thr) variant and this has significant implications with regards to future genetically-targeted treatments.

Acceptance and Commitment Therapy plus usual care for improving quality of life in people with motor neuron disease (COMMEND): a multicentre, parallel, randomised controlled trial in the UK.

BACKGROUND: Motor neuron disease is a progressive, fatal neurodegenerative disease for which there is no cure. Acceptance and Commitment Therapy (ACT) is a psychological therapy incorporating acceptance, mindfulness, and behaviour change techniques. We aimed to evaluate the effectiveness of ACT plus usual care, compared with usual care alone, for improving quality of life in people with motor neuron disease. METHODS: We conducted a parallel, multicentre, two-arm randomised controlled trial in 16 UK motor neuron disease care centres or clinics. Eligible participants were aged 18 years or older with a diagnosis of definite or laboratory-supported probable, clinically probable, or possible familial or sporadic amyotrophic lateral sclerosis; progressive muscular atrophy; or primary lateral sclerosis; which met the World Federation of Neurology's El Escorial diagnostic criteria. Participants were randomly assigned (1:1) to receive up to eight sessions of ACT adapted for people with motor neuron disease plus usual care or usual care alone by a web-based system, stratified by site. Participants were followed up at 6 months and 9 months post-randomisation. Outcome assessors and trial statisticians were masked to treatment allocation. The primary outcome was quality of life using the McGill Quality of Life Questionnaire-Revised (MQOL-R) at 6 months post-randomisation. Primary analyses were multi-level modelling and modified intention to treat among participants with available data. This trial was pre-registered with the ISRCTN Registry (ISRCTN12655391). FINDINGS: Between Sept 18, 2019, and Aug 31, 2022, 435 people with motor neuron disease were approached for the study, of whom 206 (47%) were assessed for eligibility, and 191 were recruited. 97 (51%) participants were randomly assigned to ACT plus usual care and 94 (49%) were assigned to usual care alone. 80 (42%) of 191 participants were female and 111 (58%) were male, and the mean age was 63·1 years (SD 11·0). 155 (81%) participants had primary outcome data at 6 months post-randomisation. After controlling for baseline scores, age, sex, and therapist clustering, ACT plus usual care was superior to usual care alone for quality of life at 6 months (adjusted mean difference on the MQOL-R of 0·66 [95% CI 0·22-1·10]; d=0·46 [0·16-0·77]; p=0·0031). Moderate effect sizes were clinically meaningful. 75 adverse events were reported, 38 of which were serious, but no adverse events were deemed to be associated with the intervention. INTERPRETATION: ACT plus usual care is clinically effective for maintaining or improving quality of life in people with motor neuron disease. As further evidence emerges confirming these findings, health-care providers should consider how access to ACT, adapted for the specific needs of people with motor neuron disease, could be provided within motor neuron disease clinical services. FUNDING: National Institute for Health and Care Research Health Technology Assessment and Motor Neurone Disease Association.

Genotype-phenotype characterisation of long survivors with motor neuron disease in Scotland.

BACKGROUND: We investigated the phenotypes and genotypes of a cohort of 'long-surviving' individuals with motor neuron disease (MND) to identify potential targets for prognostication. METHODS: Patients were recruited via the Clinical Audit Research and Evaluation for MND (CARE-MND) platform, which hosts the Scottish MND Register. Long survival was defined as > 8 years from diagnosis. 11 phenotypic variables were analysed. Whole genome sequencing (WGS) was performed and variants within 49 MND-associated genes examined. Each individual was screened for C9orf72 repeat expansions. Data from ancestry-matched Scottish populations (the Lothian Birth Cohorts) were used as controls. RESULTS: 58 long survivors were identified. Median survival from diagnosis was 15.5 years. Long survivors were significantly younger at onset and diagnosis than incident patients and had a significantly longer diagnostic delay. 42% had the MND subtype of primary lateral sclerosis (PLS). WGS was performed in 46 individuals: 14 (30.4%) had a potentially pathogenic variant. 4 carried the known SOD1 p.(Ile114Thr) variant. Significant variants in FIG4, hnRNPA2B1, SETX, SQSTM1, TAF15, and VAPB were detected. 2 individuals had a variant in the SPAST gene suggesting phenotypic overlap with hereditary spastic paraplegia (HSP). No long survivors had pathogenic C9orf72 repeat expansions. CONCLUSIONS: Long survivors are characterised by younger age at onset, increased prevalence of PLS and longer diagnostic delay. Genetic analysis in this cohort has improved our understanding of the phenotypes associated with the SOD1 variant p.(Ile114Thr). Our findings confirm that pathogenic expansion of C9orf72 is likely a poor prognostic marker. Genetic screening using targeted MND and/or HSP panels should be considered in those with long survival, or early-onset slowly progressive disease, to improve diagnostic accuracy and aid prognostication.

Mutations in protein kinase Cγ promote spinocerebellar ataxia type 14 by impairing kinase autoinhibition.

Spinocerebellar ataxia type 14 (SCA14) is a neurodegenerative disease caused by germline variants in the diacylglycerol (DAG)/Ca2+-regulated protein kinase Cγ (PKCγ), leading to Purkinje cell degeneration and progressive cerebellar dysfunction. Most of the identified mutations cluster in the DAG-sensing C1 domains. Here, we found with a FRET-based activity reporter that SCA14-associated PKCγ mutations, including a previously undescribed variant, D115Y, enhanced the basal activity of the kinase by compromising its autoinhibition. Unlike other mutations in PKC that impair its autoinhibition but lead to its degradation, the C1 domain mutations protected PKCγ from such down-regulation. This enhanced basal signaling rewired the brain phosphoproteome, as revealed by phosphoproteomic analysis of cerebella from mice expressing a human SCA14-associated H101Y mutant PKCγ transgene. Mutations that induced a high basal activity in vitro were associated with earlier average age of onset in patients. Furthermore, the extent of disrupted autoinhibition, but not agonist-stimulated activity, correlated with disease severity. Molecular modeling indicated that almost all SCA14 variants not within the C1 domain were located at interfaces with the C1B domain, suggesting that mutations in and proximal to the C1B domain are a susceptibility for SCA14 because they uniquely enhance PKCγ basal activity while protecting the enzyme from down-regulation. These results provide insight into how PKCγ activation is modulated and how deregulation of the cerebellar phosphoproteome by SCA14-associated mutations affects disease progression.

Efficacy of erenumab and factors predicting response after 3 months in treatment resistant chronic migraine: a clinical service evaluation.

BACKGROUND: Calcitonin gene-related peptide (CGRP) inhibitors have been developed as options for treatment of chronic and episodic migraine. We present our experience of the use of erenumab in a tertiary headache centre. METHODS: This was a prospective clinical audit of all patients commenced on erenumab following a locally agreed pathway and criteria over a consecutive period. Patients received monthly erenumab 140 mg for 3 months. Data were collected prospectively at baseline and 3 months follow up. RESULTS: One hundred three patients were commenced on erenumab during the study period. Patients had tried a median of 7 previous prophylactics, including onabotulinum toxin A in 94%. At 3 months there was a reduction in median total (28 to 20, 29% reduction, p < 0.0001) and severe (15 to 5, 67% reduction, p < 0.0001) headache days. 39.8% of patients achieved at least a 30% reduction in total headache days; 61.8% of patients achieved at least a 50% reduction in severe headache days. Meeting either of these thresholds was considered a positive response, 68% of patients achieved this. Presence of daily headache pattern was negatively associated with response, (56% response vs. 90% without daily headache, p = 0.0003). There was no association between age, gender, presence of medication overuse or number of previously tried prophylactic treatments and response to erenumab. 43% of patients reported at least one adverse effect, most commonly constipation (26%); treatment was discontinued in 3 patients due to adverse effects. CONCLUSIONS: Erenumab was an effective treatment for chronic migraine in this treatment resistant population over 3 months of follow up. Presence of daily headache predicted poorer response but there was still a significant positive response rate in this group.

Clinical trials in amyotrophic lateral sclerosis: a systematic review and perspective.

Amyotrophic lateral sclerosis is a progressive and devastating neurodegenerative disease. Despite decades of clinical trials, effective disease-modifying drugs remain scarce. To understand the challenges of trial design and delivery, we performed a systematic review of Phase II, Phase II/III and Phase III amyotrophic lateral sclerosis clinical drug trials on trial registries and PubMed between 2008 and 2019. We identified 125 trials, investigating 76 drugs and recruiting more than 15 000 people with amyotrophic lateral sclerosis. About 90% of trials used traditional fixed designs. The limitations in understanding of disease biology, outcome measures, resources and barriers to trial participation in a rapidly progressive, disabling and heterogenous disease hindered timely and definitive evaluation of drugs in two-arm trials. Innovative trial designs, especially adaptive platform trials may offer significant efficiency gains to this end. We propose a flexible and scalable multi-arm, multi-stage trial platform where opportunities to participate in a clinical trial can become the default for people with amyotrophic lateral sclerosis.

Fit for purpose? A cross-sectional study to evaluate the acceptability and usability of HeadUp, a novel neck support collar for neurological neck weakness.

The HeadUp collar (previously known as the Sheffield Support Snood) provides support for neck weakness caused by amyotrophic lateral sclerosis (ALS) and has shown to be superior to alternative options in a small cohort of patients from one single center. Here we report the assessment of the HeadUp collar in a larger cohort of patients, exploring the use in other neurological conditions and expanding to other centers across the UK and Ireland. An interventional cross-sectional study design was implemented to investigate the usability and acceptability of the HeadUp collar. A total of 139 patients were recruited for the study, 117 patients had a diagnosis of ALS and 22 patients presented with neck weakness due to other neurological conditions. Participants were assessed at baseline, fitted a HeadUp collar and followed-up one month later. The performance of the HeadUp collar was rated favorably compared to previously worn collars in terms of the ability to eat, drink and swallow. Findings suggest that the collar also permitted a more acceptable range of head movements whilst maintaining a good level of support. We conclude that the HeadUp collar is a suitable option for patients with neck weakness due to ALS and other neurological conditions.

Improved survival and 30-day mortality after gastrostomy in Scottish motor neurone disease patients: evidence from a national retrospective cohort study using STROBE criteria.

Objectives: Defining historical changes and outcomes in the use of gastrostomy in the management of Scottish MND patients. Methods: The 1989-1998 and 2015-2016 Scottish national MND cohorts were used to examine the frequency, timing, and survival related to gastrostomy. The cohorts were censored for survival analysis. Results: There were 261 cases, 119 (46%) from the new register (2015-2016) and 142 (54%) from the old register (1989-1999). Percutaneous endoscopic gastrostomy (PEG) tubes were used exclusively in the old register vs. the new register where PEG (45%), Radiologically inserted gastrostomy (RIG) (44%) and a small number of peroral image-guided gastrostomy (PIGG) tubes (11%), p < 0.01 were used. Odds of 30-d mortality in the old register were 2.8 times that in the new register, p < 0.01. Median survival time from gastrostomy was significantly higher in the new register, 2.7 months, p < 0.05. Median survival time from onset was also higher in the new register but non-significant, 3.2 months, p = 0.30. Multivariate analysis identified age at onset (hazard ratio [HR] 1.02 p = 0.01), time from onset to diagnosis (HR 0.74 p < 0.01), subtype of onset (HR 1.52 p = 0.01), with gastrostomy and Riluzole interacting as variables that predict risk of death. Conclusions: Gastrostomy use has increased with techniques changing over time. It is safer and survival time has increased post gastrostomy. Being older and diagnosed more quickly increases risk of death whilst taking Riluzole combined with gastrostomy reduced risk of death. Survival from onset has not significantly changed in Scottish MND patients having gastrostomy.

Clinical audit research and evaluation of motor neuron disease (CARE-MND): a national electronic platform for prospective, longitudinal monitoring of MND in Scotland.

Objectives: Launched in 1989, the Scottish Motor Neuron Disease Register (SMNDR) has provided a resource for prospective clinical data collection. However, in 2015 we aimed to evolve a system to allow: i) A patient-centered approach to care based on recognized standards, ii) Harmonized data sharing between Scottish health professionals in "real-time", iii) Regular audit of care to facilitate timely improvements in service delivery, and iv) Patient participation in a diverse range of observational and interventional research studies including clinical trials. Methods: We developed a standardized national electronic data platform-Clinical Audit Research and Evaluation of MND (CARE-MND) which integrates clinical audit and research data fields. Data completion pre- and post-CARE-MND were compared, guided by recently published National Institute for Clinical Excellence (NICE) recommendations. Statistical difference in data capture between time periods was assessed using Z-test of proportions. Results: Data field completion for the historical 2011-2014 period ranged from 4 to 95%; median 50%. CARE-MND capture ranged from 32 to 98%; median 87%. 15/17 fields were significantly more complete post-CARE-MND (p < 0.001). All MND nurse/allied health specialists in Scotland use the CARE-MND platform. Management of MND in Scotland is now coordinated through a standardized template. Conclusions: Through CARE-MND, national audits of MND care and interventions have been possible, leading to protocols for harmonized service provision. Stratification of the MND population is facilitating participation in observational and interventional studies. CARE-MND can act as a template for other neurological disorders.

Cancer and motor neuron disease-causal or coincidental? Two contrasting cases.

INTRODUCTION: Motor neuron disease (MND) can occur in patients with cancer, but there is minimal evidence that this is more than by chance. We contrast two cases of motor neuronopathies occurring in the context of systemic malignancy and argue that in one case the cause was most likely paraneoplastic, while in the other it was not. CASE 1: A 61-year-old woman developed progressive walking difficulties over 9 months with weakness and stiffness in her legs. EMG showed fibrillations and positive sharp waves in multiple lower limb muscles bilaterally, with neurogenic units and a reduced recruitment pattern. An invasive ductal carcinoma of the breast was identified and she continued to deteriorate neurologically with worsening mobility, upper limb spasticity and fasciculations. She died approximately 26 months after symptom onset. CASE 2: A 57-year-old woman developed weight loss and weakness of her right arm without any sensory symptoms. At presentation, she had wasting and fasciculations in her right upper limb muscles, with normal reflexes, normal left upper limb and lower limb examination. Over the following week, she developed left upper limb weakness and fasciculations, brisk knee reflexes, and flexor plantar responses. Her EMG showed upper and lower limb denervation. She was found to have anti-Hu and anti-CV2 antibodies present in serum. A PET-CT showed active uptake in lymph nodes in the right hilum. Biopsy confirmed a small cell lung cancer. She had chemoradiation therapy and the tumour went into remission. She has remained well on follow-up 24 months later, regaining weight and strength after her chemotherapy. She continues to be monitored for cancer recurrence, but thus far appears to be in remission. CONCLUSION: In cases with rapidly progressive MND, particularly of upper limb onset, consideration should be given to testing anti-neuronal antibodies and searching for an occult tumour.

Changing epidemiology of motor neurone disease in Scotland.

OBJECTIVES: Scotland benefits from an integrated national healthcare team for motor neurone disease (MND) and a tradition of rich clinical data capture using the Scottish MND Register (launched in 1989; one of the first national registers). The Scottish register was re-launched in 2015 as Clinical Audit Research and Evaluation of MND (CARE-MND), an electronic platform for prospective, population-based research. We aimed to determine if incidence of MND is changing over time. METHODS: Capture-recapture methods determined the incidence of MND in 2015-2016. Incidence rates for 2015-2016 and 1989-1998 were direct age and sex standardised to allow time-period comparison. Phenotypic characteristics and socioeconomic status of the cohort are described. RESULTS: Coverage of the CARE-MND platform was 99%. Crude incidence in the 2015-2017 period was 3.83/100,000 person-years (95% CI 3.53-4.14). Direct age-standardised incidence in 2015 was 3.42/100,000 (95% CI 2.99-3.91); in 2016, it was 2.89/100,000 (95% CI 2.50-3.34). The 1989-1998 direct standardised annual incidence estimate was 2.32/100,000 (95% CI 2.26-2.37). 2015-2016 standardised incidence was 66.9% higher than Northern European estimates. Socioeconomic status was not associated with MND. CONCLUSIONS: Our data show a changing landscape of MND in Scotland, with a rise in incidence by 36.0% over a 25-year period. This is likely attributable to ascertainment in the context of improved neurological services in Scotland. Our data suggest that CARE-MND is a reliable national resource and findings can be extrapolated to the other Northern European populations.

Wound botulism, its neurological manifestations, treatment and outcomes: A case series from the Glasgow outbreak, 2015.

Background and aims We examined the neurological manifestations, treatment and outcomes of a subset of 25 patients within the largest ever outbreak of wound botulism in Europe. Methods and results All 25 cases were intravenous drug users. The most common presenting symptom was dysarthria in 19/25 (76%), followed by dysphagia in 12/25 (48%), blurred vision in 10/25 (40%) and double vision in 8/25 (32%). Microbiological analysis confirmed the diagnosis in nine cases (36%). Duration of admission positively correlated with time to antitoxin, time to wound debridement and female sex. Conclusion As the outbreak continued, hospital stays shortened, reflecting growing awareness of the outbreak and quicker treatment initiation.

Genetic epidemiology of motor neuron disease-associated variants in the Scottish population.

Genetic understanding of motor neuron disease (MND) has evolved greatly in the past 10 years, including the recent identification of association between MND and variants in TBK1 and NEK1. Our aim was to determine the frequency of pathogenic variants in known MND genes and to assess whether variants in TBK1 and NEK1 contribute to the burden of MND in the Scottish population. SOD1, TARDBP, OPTN, TBK1, and NEK1 were sequenced in 441 cases and 400 controls. In addition to 44 cases known to carry a C9orf72 hexanucleotide repeat expansion, we identified 31 cases and 2 controls that carried a loss-of-function or pathogenic variant. Loss-of-function variants were found in TBK1 in 3 cases and no controls and, separately, in NEK1 in 3 cases and no controls. This study provides an accurate description of the genetic epidemiology of MND in Scotland and provides support for the contribution of both TBK1 and NEK1 to MND susceptibility in the Scottish population.

A multicentre evaluation of oropharyngeal secretion management practices in amyotrophic lateral sclerosis.

Failure to clear oral secretions can be debilitating for patients with amyotrophic lateral sclerosis (ALS), but the treatment of this symptom is poorly defined and there is no consensus on best practice. The objective of this study was to identify the treatments that are commonly prescribed, and to describe how experienced clinicians manage a patient with treatment resistant symptoms. Twenty-three clinicians were approached, of which 19 from 16 centres across the UK provided case report forms for a total of 119 ALS patients identified as having problematic oral secretions. The use of five anticholinergics, salivary gland botulinum toxin injections, conservative management approaches and carbocisteine were reported. Of the 72 patients who were evaluated following the initiation of a first anticholinergic, 61% had symptomatic improvement. Only 19% of patients achieved symptomatic improvement with the use of an alternative anticholinergic when an initial anticholinergic achieved no symptomatic improvement. Problems with thick and thin secretions often coexisted, with 37% of patients receiving treatment for both types of problem. In conclusion, a variety of treatment options are employed by expert clinicians for problematic oral secretions in ALS patients. The variation in management highlights the need for further prospective research in this area.

Improved PCR based methods for detecting C9orf72 hexanucleotide repeat expansions.

Due to the GC-rich, repetitive nature of C9orf72 hexanucleotide repeat expansions, PCR based detection methods are challenging. Several limitations of PCR have been reported and overcoming these could help to define the pathogenic range. There is also a need to develop improved repeat-primed PCR assays which allow detection even in the presence of genomic variation around the repeat region. We have optimised PCR conditions for the C9orf72 hexanucleotide repeat expansion, using betaine as a co-solvent and specific cycling conditions, including slow ramping and a high denaturation temperature. We have developed a flanking assay, and repeat-primed PCR assays for both 3' and 5' ends of the repeat expansion, which when used together provide a robust strategy for detecting the presence or absence of expansions greater than ∼100 repeats, even in the presence of genomic variability at the 3' end of the repeat. Using our assays, we have detected repeat expansions in 47/442 Scottish ALS patients. Furthermore, we recommend the combined use of these assays in a clinical diagnostic setting.

Dendritic spinopathy in transgenic mice expressing ALS/dementia-linked mutant UBQLN2.

Mutations in the gene encoding ubiquilin2 (UBQLN2) cause amyotrophic lateral sclerosis (ALS), frontotemporal type of dementia, or both. However, the molecular mechanisms are unknown. Here, we show that ALS/dementia-linked UBQLN2(P497H) transgenic mice develop neuronal pathology with ubiquilin2/ubiquitin/p62-positive inclusions in the brain, especially in the hippocampus, recapitulating several key pathological features of dementia observed in human patients with UBQLN2 mutations. A major feature of the ubiquilin2-related pathology in these mice, and reminiscent of human disease, is a dendritic spinopathy with protein aggregation in the dendritic spines and an associated decrease in dendritic spine density and synaptic dysfunction. Finally, we show that the protein inclusions in the dendritic spines are composed of several components of the proteasome machinery, including Ub(G76V)-GFP, a representative ubiquitinated protein substrate that is accumulated in the transgenic mice. Our data, therefore, directly link impaired protein degradation to inclusion formation that is associated with synaptic dysfunction and cognitive deficits. These data imply a convergent molecular pathway involving synaptic protein recycling that may also be involved in other neurodegenerative disorders, with implications for development of widely applicable rational therapeutics.

Mutations in the SPG7 gene cause chronic progressive external ophthalmoplegia through disordered mitochondrial DNA maintenance.

Despite being a canonical presenting feature of mitochondrial disease, the genetic basis of progressive external ophthalmoplegia remains unknown in a large proportion of patients. Here we show that mutations in SPG7 are a novel cause of progressive external ophthalmoplegia associated with multiple mitochondrial DNA deletions. After excluding known causes, whole exome sequencing, targeted Sanger sequencing and multiplex ligation-dependent probe amplification analysis were used to study 68 adult patients with progressive external ophthalmoplegia either with or without multiple mitochondrial DNA deletions in skeletal muscle. Nine patients (eight probands) were found to carry compound heterozygous SPG7 mutations, including three novel mutations: two missense mutations c.2221G>A; p.(Glu741Lys), c.2224G>A; p.(Asp742Asn), a truncating mutation c.861dupT; p.Asn288*, and seven previously reported mutations. We identified a further six patients with single heterozygous mutations in SPG7, including two further novel mutations: c.184-3C>T (predicted to remove a splice site before exon 2) and c.1067C>T; p.(Thr356Met). The clinical phenotype typically developed in mid-adult life with either progressive external ophthalmoplegia/ptosis and spastic ataxia, or a progressive ataxic disorder. Dysphagia and proximal myopathy were common, but urinary symptoms were rare, despite the spasticity. Functional studies included transcript analysis, proteomics, mitochondrial network analysis, single fibre mitochondrial DNA analysis and deep re-sequencing of mitochondrial DNA. SPG7 mutations caused increased mitochondrial biogenesis in patient muscle, and mitochondrial fusion in patient fibroblasts associated with the clonal expansion of mitochondrial DNA mutations. In conclusion, the SPG7 gene should be screened in patients in whom a disorder of mitochondrial DNA maintenance is suspected when spastic ataxia is prominent. The complex neurological phenotype is likely a result of the clonal expansion of secondary mitochondrial DNA mutations modulating the phenotype, driven by compensatory mitochondrial biogenesis.