The novel MAPT mutation K298E: mechanisms of mutant tau toxicity, brain pathology and tau expression in induced fibroblast-derived neurons.

Frontotemporal lobar degeneration (FTLD) consists of a group of neurodegenerative diseases characterized by behavioural and executive impairment, language disorders and motor dysfunction. About 20-30% of cases are inherited in a dominant manner. Mutations in the microtubule-associated protein tau gene (MAPT) cause frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17T). Here we report a novel MAPT mutation (K298E) in exon 10 in a patient with FTDP-17T. Neuropathological studies of post-mortem brain showed widespread neuronal loss and gliosis and abundant deposition of hyperphosphorylated tau in neurons and glia. Molecular studies demonstrated that the K298E mutation affects both protein function and alternative mRNA splicing. Fibroblasts from a skin biopsy of the proband taken at post-mortem were directly induced into neurons (iNs) and expressed both 3-repeat and 4-repeat tau isoforms. As well as contributing new knowledge on MAPT mutations in FTDP-17T, this is the first example of the successful generation of iNs from skin cells retrieved post-mortem.

Statistical analysis plan for the motor neuron disease systematic multi-arm adaptive randomised trial (MND-SMART).

BACKGROUND: MND-SMART is a platform, multi-arm, multi-stage, multi-centre, randomised controlled trial recruiting people with motor neuron disease. Initially, the treatments memantine and trazodone will each be compared against placebo, but other investigational treatments will be introduced into the trial later. The co-primary outcomes are the Amyotrophic Lateral Sclerosis Functional Rating Scale Revised (ALS-FRS-R) functional outcome, which is assessed longitudinally, and overall survival. METHODS: Initially in MND-SMART, participants are randomised 1:1:1 via a minimisation algorithm to receive placebo or one of the two investigational treatments with up to 531 to be randomised in total. The comparisons between each research arm and placebo will be conducted in four stages, with the opportunity to cease further randomisations to poorly performing research arms at the end of stages 1 or 2. The final ALS-FRS-R analysis will be at the end of stage 3 and final survival analysis at the end of stage 4. The estimands for the co-primary outcomes are described in detail. The primary analysis of ALS-FRS-R at the end of stages 1 to 3 will involve fitting a normal linear mixed model to the data to calculate a mean difference in rate of ALS-FRS-R change between each research treatment and placebo. The pairwise type 1 error rate will be controlled, because each treatment comparison will generate its own distinct and separate interpretation. This publication is based on a formal statistical analysis plan document that was finalised and signed on 18 May 2022. DISCUSSION: In developing the statistical analysis plan, we had to carefully consider several issues such as multiple testing, estimand specification, interim analyses, and statistical analysis of the repeated measurements of ALS-FRS-R. This analysis plan attempts to balance multiple factors, including minimisation of bias, maximising power and precision, and deriving clinically interpretable summaries of treatment effects. TRIAL REGISTRATION: EudraCT Number, 2019-000099-41. Registered 2 October 2019, https://www.clinicaltrialsregister.eu/ctr-search/search?query=mnd-smart ClinicalTrials.gov, NCT04302870 . Registered 10 March 2020.

Motor Neuron Disease Systematic Multi-Arm Adaptive Randomised Trial (MND-SMART): a multi-arm, multi-stage, adaptive, platform, phase III randomised, double-blind, placebo-controlled trial of repurposed drugs in motor neuron disease.

INTRODUCTION: Motor neuron disease (MND) is a rapidly fatal neurodegenerative disease. Despite decades of research and clinical trials there remains no cure and only one globally approved drug, riluzole, which prolongs survival by 2-3 months. Recent improved mechanistic understanding of MND heralds a new translational era with many potential targets being identified that are ripe for clinical trials. Motor Neuron Disease Systematic Multi-Arm Adaptive Randomised Trial (MND-SMART) aims to evaluate the efficacy of drugs efficiently and definitively in a multi-arm, multi-stage, adaptive trial. The first two drugs selected for evaluation in MND-SMART are trazodone and memantine. METHODS AND ANALYSIS: Initially, up to 531 participants (177/arm) will be randomised 1:1:1 to oral liquid trazodone, memantine and placebo. The coprimary outcome measures are the Amyotrophic Lateral Sclerosis Functional Rating Scale Revised (ALSFRS-R) and survival. Comparisons will be conducted in four stages. The decision to continue randomising to arms after each stage will be made by the Trial Steering Committee who receive recommendations from the Independent Data Monitoring Committee. The primary analysis of ALSFRS-R will be conducted when 150 participants/arm, excluding long survivors, have completed 18 months of treatment; if positive the survival effect will be inferentially analysed when 113 deaths have been observed in the placebo group. The trial design ensures that other promising drugs can be added for evaluation in planned trial adaptations. Using this novel trial design reduces time, cost and number of participants required to definitively (phase III) evaluate drugs and reduces exposure of participants to potentially ineffective treatments. ETHICS AND DISSEMINATION: MND-SMART was approved by the West of Scotland Research Ethics Committee on 2 October 2019. (REC reference: 19/WS/0123) Results of the study will be submitted for publication in a peer-reviewed journal and a summary provided to participants. TRIAL REGISTRATION NUMBERS: European Clinical Trials Registry (2019-000099-41); NCT04302870.

Incidence of amyotrophic lateral sclerosis in Europe.

BACKGROUND: Geographical differences in the incidence of amyotrophic lateral sclerosis (ALS) have been reported in the literature but comparisons across previous studies are limited by different methods in case ascertainment and by the relatively small size of the studied populations. To address these issues, the authors undertook a pooled analysis of European population based ALS registries. METHODS: All new incident ALS cases in subjects aged 18 years old and older were identified prospectively in six population based registries in three European countries (Ireland, UK and Italy) in the 2 year period 1998-1999, with a reference population of almost 24 million. RESULTS: Based on 1028 identified incident cases, the crude annual incidence rate of ALS in the general European population was 2.16 per 100 000 person years; 95% CI 2.0 to 2.3), with similar incidence rates across all registries. The incidence was higher among men (3.0 per 100 000 person years; 95% CI 2.8 to 3.3) than among women (2.4 per 100 000 person years; 95% CI 2.2 to 2.6). Spinal onset ALS was more common among men compared with women, particularly in the 70-80 year age group. Disease occurrence decreased rapidly after 80 years of age. CONCLUSIONS: ALS incidence is homogeneous across Europe. Sex differences in incidence may be explained by the higher incidence of spinal onset ALS among men, and the age related disease pattern suggests that ALS occurs within a susceptible group within the population rather than being a disease of ageing.

50bp deletion in the promoter for superoxide dismutase 1 (SOD1) reduces SOD1 expression in vitro and may correlate with increased age of onset of sporadic amyotrophic lateral sclerosis.

The objective was to test the hypothesis that a described association between homozygosity for a 50bp deletion in the SOD1 promoter 1684bp upstream of the SOD1 ATG and an increased age of onset in SALS can be replicated in additional SALS and control sample sets from other populations. Our second objective was to examine whether this deletion attenuates expression of the SOD1 gene. Genomic DNA from more than 1200 SALS cases from Ireland, Scotland, Quebec and the USA was genotyped for the 50bp SOD1 promoter deletion. Reporter gene expression analysis, electrophoretic mobility shift assays and chromatin immunoprecipitation studies were utilized to examine the functional effects of the deletion. The genetic association for homozygosity for the promoter deletion with an increased age of symptom onset was confirmed overall in this further study (p=0.032), although it was only statistically significant in the Irish subset, and remained highly significant in the combined set of all cohorts (p=0.001). Functional studies demonstrated that this polymorphism reduces the activity of the SOD1 promoter by approximately 50%. In addition we revealed that the transcription factor SP1 binds within the 50bp deletion region in vitro and in vivo. Our findings suggest the hypothesis that this deletion reduces expression of the SOD1 gene and that levels of the SOD1 protein may modify the phenotype of SALS within selected populations.

A population based study of respiratory function in motor neuron disease patients living in Tayside and North East Fife, Scotland.

Respiratory failure is a major cause of morbidity and the principal cause of death in motor neuron disease; non-invasive ventilation is increasingly used worldwide to palliate the respiratory symptoms. This observational study was designed to evaluate the prevalence of respiratory insufficiency within the motor neuron disease population of Tayside and North East Fife, Scotland. Twenty-six patients were identified, their diagnosis confirmed according to agreed criteria and subjected to the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale, the Epworth Sleepiness questionnaire; spirometry, sniff nasal inspiratory pressure and nocturnal pulse oximetry measurements.Twenty-two (84.6%) patients reported one or more symptoms of respiratory insufficiency, 19 patients (73%) had forced vital capacity <80% of predicted in the sitting position and 10 (38.5%) had oxygen saturation <90% for >5% of night. On this basis a potential 10 patients required consideration for ventilation. As well as probable improvement in quality of life and survival for those patients this potential increase in workload has major educational, management and resource implications for health care providers.

The incidence of motor nueron disease in Scotland.

Between 1989 and 1998, 1226 cases of ALS/MND were identified in Scotland, with mean age of onset 65.2 (SD 11.9) years for men and 67.2 (SD 11.0) for women. Annual standardized incidence was 2.40 per 100,000 (95% CI 2.22-2.58). Using capture recapture methods we confirm a high level of case ascertainment for each year of study. Incidence and ascertainment of ALS has remained stable in a large population over a prolonged period of time. Large population-based databases can be used to test aetiological hypotheses.

Frequency, timing and outcome of gastrostomy tubes for amyotrophic lateral sclerosis/motor neurone disease--a record linkage study from the Scottish Motor Neurone Disease Register.

AIMS: To describe the frequency, timing and outcome from gastrostomy in amyotrophic lateral sclerosis/motor neurone disease (ALS/MND). METHODS: The Scottish MND Register, a population based disease register (1989-1998), with record linkage to the Scottish Morbidity 1 dataset of hospital discharges coded for gastrostomy procedure was used. Descriptive statistics of patients undergoing gastrostomy were extracted. Survival analysis used Kaplan Meier and Cox proportional hazards methods. RESULTS: For patients diagnosed between 1989-98, 142 percutaneous endoscopic gastrostomy (PEG) insertion episodes were identified in 1226 patients, 130 of which occurred before the censoring date of 31 December 1999.Annually, on average, 5% of all revalent patients underwent gastrostomy, and this rate appeared to double between 1989-98. The cumulative incidence of gastrostomy was 11%. Mean age at PEG tube insertion was 66.8 years, with a mean disease duration of 24 months. Median survival from PEG tube insertion was 146 days. The 1 month mortality after gastrostomy was 25%. Gastrostomy did not confer a survival advantage compared with no gastrostomy. CONCLUSIONS: We found that gastrostomy feeding tubes are being inserted more frequently in people with ALS/MND. An unexpectedly high early mortality was detected which probably reflects a lack of selection bias compared with previously published data. It is possible that changes in the practice of gastrostomy placement since 1998 result in better outcomes for patients with ALS/MND. Prospective studies are required to assess the risks and benefits of enteral nutrition in ALS/MND.

Use of intravenous immunoglobulin in the Department of Neurology at Ninewells Hospital, 2008-2009: Indications for utilization and cost-effectiveness.

UNLABELLED: This study was designed to identify the indications for prescription of intravenous immunoglobulin (IVIg) in neurology and the cost effectiveness of this therapy. OBJECTIVES: IVIg is a relatively costly therapy and the annual budget spent on providing this therapy for various indications at Ninewells Hospital was close to £1.5 million. In today's economic times, a cost-benefit analysis of all therapies is prudent. This is of relevance to countries in the developing world as well where perhaps not everybody could afford such cost-intensive therapy. MATERIALS AND METHODS: We audited 2 time periods over 12 months each in 2004-2005 and 2008-2009 to look at the patterns of utilization of IVIg over these periods. We searched the literature for alternative and cost-effective therapies for the most common indications for use of IVIg. RESULTS: Fiscal costs on prescription of IVIg have rocketed up by almost 300% in this Neurology Department comparing data from 2004-2005 vs 2008-2009 and this is disproportionate to the increase in the annual admission rate (bed usage), partly because of the soaring costs of the drug available in the market and also because of the increased prescription of IVIg for numerous indications where clinical trials data are yet not so robust. CONCLUSION: We have looked at the cost of alternative therapies and offer some proposals that if implemented could potentially save £330,000 annually from the health budget at this NHS Trust. Perhaps similar models could evolve for better cost-effective utilization of IVIg in countries in the developing world where health budgeting is more acutely relevant.

Multiple sclerosis in Tayside, Scotland: detection of clusters using a spatial scan statistic.

Debate continues over the relative importance of genetic factors over infectious agents in the aetiology of multiple sclerosis (MS). Detection of clusters of MS in space and time in the Tayside region of Scotland, UK would provide valuable evidence for the movement of infectious agents into a genetically susceptible population. A spatial scan statistic was used to detect, locate and provide a robust statistical test of any clusters found, without prior knowledge of their location or size. This was applied to a population-based MS register for the Tayside region of Scotland from 1970 to 1997, allowing for age at symptom onset, gender, population density and social deprivation. There were a total of 772 cases during the study period; an annual incidence of 72 per 100000. The mean age of symptom onset was 35.7 (SD = 10.5) and 73.8% of cases were women. There was a general increase in cases over time probably reflecting gradually better detection and diagnosis. There was a peak around the mid-1990s and some evidence of periodicity. There was a highly significant temporal cluster between 1982 and 1995 (P = 0.002) for the whole region. Additionally, a significant spatial cluster for the time period 1993-1995 was found centred in the rural area south-west of Perth (P=0.016). Significant temporal and spatial-temporal clusters are consistent with exogenous factors contributing to the distribution of MS in Tayside, Scotland.

The epidemiology of amyotrophic lateral sclerosis (ALS/MND) in people aged 80 or over.

OBJECTIVE: To describe the clinical features, incidence, survival and process of care of people with Amyotrophic Lateral Sclerosis/Motor Neurone Disease aged 80 years or more at diagnosis. DESIGN: Prospective, population-based descriptive epidemiological study. SETTING: Scotland (population 5.1 million), The Scottish Motor Neurone Disease Register 1989-1998. PARTICIPANTS: 135 people aged 80 years or over at diagnosis. METHODS: Descriptive Epidemiology of Amyotrophic Lateral Sclerosis/Motor Neurone Disease in the over 80s. Survival described using Kaplan-Meier curves. RESULTS: 135 of 1226 cases (11%) were aged 80 years or more. Sixty-seven (50%) had bulbar onset, and 58 (43%) were men. The standardised incidence was 10.2/100000 (95% CI 7.4-13.1) in men and 6.1/100000 (95% CI = 4.3-7.6) in women. Median survival from first symptoms was 1.7 years (IQR 1.0-2.8), less than younger patients (P = 0.0003; log Rank test). We found evidence of differences in the process of care, as older people were less likely to be prescribed Riluzole (OR 0.12, 95% CI = 0.02-0.89) or be assessed by a neurologist (OR 0.76, 95% CI = 0.67-0.86). CONCLUSION: This is the first comprehensive report of the epidemiology of Amyotrophic Lateral Sclerosis/Motor Neurone Disease in older people. Clinical presentation and survival differ from the population as a whole. There is evidence of a different process of care. While this may be to the detriment of their survival, this finding would need to be confirmed by further prospective studies.