Phenotypical differences of C9ORF72 gene-positive and negative amyotrophic lateral sclerosis: a comparative case series

BACKGROUND

Hexanucleotide repeat expansions of C9ORF72 account for a significant proportion of autosomal dominant neurodegenerative diseases in the amyotrophic lateral sclerosis (ALS)-frontotemporal dementia spectrum. In the absence of a family history, clinical identification of such patients remains difficult. We aimed to identify differences in demographics and clinical presentation between patients with C9ORF72 gene-positive ALS (C9pALS) versus C9ORF72 gene-negative ALS (C9nALS), to aid identification of these patients in the clinic and examine differences in outcomes including survival.

METHODS

We retrospectively reviewed the clinical presentations of 32 patients with C9pALS and compared their characteristics with a cohort of 46 patients with C9nALS from the same tertiary neurosciences centre.

RESULTS

Patients with C9pALS more commonly presented with mixed upper and lower motor signs (C9pALS 87.5%, C9nALS 65.2%; p=0.0352), but less frequently presented with purely upper motor neuron signs (C9pALS 3.1%, C9nALS 21.7%; p=0.0226). The C9pALS cohort had a higher frequency of cognitive impairment (C9pALS 31.3%, C9nALS 10.9%; p=0.0394) and bulbar disease (C9pALS 56.3%, C9nALS 28.3%; p=0.0186). There were no differences between cohorts in age at diagnosis, gender, limb weakness, respiratory symptoms, presentation with predominantly lower motor neuron signs or overall survival.

DISCUSSION

Analysis of this ALS clinic cohort at a UK tertiary neurosciences centre adds to the small but growing understanding of the unique clinical features of patients with C9pALS. In the age of precision medicine with expanding opportunities to manage genetic diseases with disease-modifying therapies, clinical identification of such patients is increasingly important as focused therapeutic strategies become available.

078 Myotonic dystrophy service redesign: report on a patient engagement event

Introduction

International consensus-based care recommendations for Myotonic Dystrophy Type 1 (DM1) have been published recently. Audit of the DM1 service at the Manchester Centre for Clinical Neurosciences (MCCN) against these was presented at the 2019 ABN. Significant scope for improve- ment was identified.

Methods

As part of DM1 service redesign at MCCN an engagement event was organised. Opinions of patients, carers and relatives on service provision and areas for improvement were explored. With reference to published care recommendations, attendees participated in structured small group discus- sions. Responses were recorded by a facilitator and thematic analysis performed.

Results

In total, 69 service-users attended. Themes emerging included a perceived lack of support between consultant appointments, inadequate access to specialist therapy services, a lack of awareness of available support services, and an inadequate understanding of DM1 by healthcare professionals. Suggestions for improvement included setting up joint appointments and patient forums for group discus- sion, increased use of telephone/online appointments, and setup of a more responsive service facilitated by a specialist nurse.

Conclusion

These findings have been incorporated in to the DM1 service redesign programme at MCCN, which has included the recent appointment of a neuromuscular specialist nurse. Re-audit of the service is planned.

james.dent@doctors.org.uk

084 Is there a positive correlation between single breath count and forced vital capacity?

Introduction

Monitoring respiratory function is a critical part of the management of patients with acute neuromuscular disease. Single breath count (SBC) testing is often performed as a surrogate for the Forced Vital Capacity (FVC), especially in resource poor environments. However, equivalence of these two tests has not been formally evaluated.

Methods

We will compare the SBC and FVC in 50 healthy adults. Correlation will be evaluated using linear regression and factors influencing the SBC and FVC will be investigated.

Results

To date 10 participants have been recruited (4 male, 6 female, mean age 30 years). Provisional analysis has shown a mean best SBC and FVC was 71 (SD 19) and 4.8 Litres (SD 1.3) respectively. In this small sample a significant correlation between SBC and FVC was demonstrated (p=0.03, R-squared=0.47). Recruitment is on schedule to complete by March 2020 and full results will be available for presentation at the conference.

Discussion

To our knowledge no study has directly compared SBC and FVC in healthy adult population. Our study will provide useful data to help understand the appropriateness of interchanging these tests in clinical practice.

aram.aslanyan@srft.nhs.uk

140 Baseline variation in commonly used inflammatory neuropathy clinical outcome measures

Background

Reliable outcome measures are vital for guiding immunoglobulin therapy in inflammatory neuropathy. Disease-specific outcome measures exist with statistically sound minimal clinically important difference (MCID) to detect change (I-RODS:+/-4; grip strength:+/-8kPa). Scores generally remain stable in well-treated disease but variation occurs.

Aims

To appreciate random variability of serially assessed grip strength, RODS and MRC-SS in clinically stable CIDP/MMN patients and explore early identification of non-random trends.

Methods

We performed a longitudinal study of serial outcome measures from Manchester neurosciences immunoglobulin database (June 2009 - September 2012). We used first score on maintenance dosing as baseline, and increase in dose (g/kg/month) as indicative of meaningful clinical deterioration. We cal- culated mean/SD actual and percentage change(Δ) for grip(kPa), I-RODS(logit scale) and MRC-SS(/70) over periods of clinical stability.

Results

54/152 patients had sufficient stability: 39CIDP (9F), 15MMN (2F). Median age:66 years(mean:64.8, range:28–89). ΔRODS: 313 timepoints over 0.4–83.9months (median:27.4). Median change:0(0%), mean:- 0.08(0.17%), SD:4.3(8.9%). Δgrip: 569 timepoints over 0.9–98.1months (median:29.7). Δright grip median:- 1kPa(-0.11%), mean:-0.87(-0.96%), SD:5.34(5.9%). Δleft median:0kPa(0%), mean:-0.82(-0.91%), SD:5.70(6.3%).

ΔMRC-SS: 75 timepoints over 1.9–52.7 months (median:10.7). Median change:0(0%), mean:0.59(0.83%), SD:4.73(6.8%). Analysis on trend identification and randomness is underway.

Conclusion

Appreciation of magnitude of normal variation is clinically important. Early identification of trends will influence dosing decisions.

ryan

keh@srft.nhs.uk|ABN Bursary

95

Good outcomes after aggressive treatment of immune checkpoint inhibitor related myasthenia gravis: a case series

Introduction

Myasthenia gravis (MG) is a rare but potentially life-threatening complication of immune- checkpoint inhibitor (ICI) therapy and often co-presents with myositis and myocarditis. We present a series of six patients from a tertiary oncology center.

Methods

We reviewed The Christie Hospital database of immunotherapy-related toxicity from 2017–2020. Symptom severity was assessed using the MGFA classification.

Results

Six patients with ICI-related MG were identified. The median number of preceding immunotherapy doses was 2. Common initial presenting complaints were ptosis (100%) and diplopia (50%) with 2/6 patients showing severe (MGFA > II) symptoms. Five patients had concomitant myositis and myocarditis. AChR or MuSK autoantibodies were positive in three patients. Two patients required advanced respiratory support.

All patients received urgent treatment with intravenous methylprednisolone and mycophenolate. Five also received intravenous immunoglobulin and a single patient was treated additionally with abatacept and rituximab. No patient died from MG-related complications. All were successfully discharged following the acute episode.

Discussion

Previous case series of ICI-related MG have reported high mortality rates, particularly in those with overlapping myositis/myocarditis. In our cohort we demonstrate good outcomes associated with early aggressive treatment with IVIG, IVMP, and mycophenolate. An agreed national treatment protocol or clinical discussion forum would be beneficial.

jam

weaver75@gmail.com

17

47XXY and 47XXX in Scleroderma and Myositis

Objective

We undertook this study to examine the X chromosome complement in participants with systemic sclerosis (SSc) as well as idiopathic inflammatory myopathies.

Methods

The participants met classification criteria for the diseases. All participants underwent single‐nucleotide polymorphism typing. We examined X and Y single‐nucleotide polymorphism heterogeneity to determine the number of X chromosomes. For statistical comparisons, we used χ² analyses with calculation of 95% confidence intervals.

Results

Three of seventy men with SSc had 47,XXY (P = 0.0001 compared with control men). Among the 435 women with SSc, none had 47,XXX. Among 709 men with polymyositis or dermatomyositis (PM/DM), seven had 47,XXY (P = 0.0016), whereas among the 1783 women with PM/DM, two had 47,XXX. Of 147 men with inclusion body myositis (IBM), six had 47,XXY, and 1 of the 114 women with IBM had 47,XXX. For each of these myositis disease groups, the excess 47,XXY and/or 47,XXX was significantly higher compared with in controls as well as the known birth rate of Klinefelter syndrome or 47,XXX.

Conclusion

Klinefelter syndrome (47,XXY) is associated with SSc and idiopathic inflammatory myopathies, similar to other autoimmune diseases with type 1 interferon pathogenesis, namely, systemic lupus erythematosus and Sjögren syndrome.

P72 Muscle weakness affects function differently in males and females in inclusion body myositis: providing results for focused clinical care and clinical trial design

Background

Sporadic inclusion body myositis (IBM) is a muscle wasting disorder usually affecting those aged over 50 years, characterised by slowly progressive weakness of the distal upper limbs and proximal lower limbs. Particular weakness of pinch, knee extension and ankle dorsiflexion result in functional decline and disability. Weakness-associated functional decline differences between genders has not previously been investigated. This study aimed to investigate for differences of functional decline in men and women with IBM.

Methods

A cohort of verified adult IBM patients were followed at a single specialist neuromuscular clinic (Royal Victoria Infirmary, Newcastle-upon-Tyne, UK) between 2004-15, with data collected at each clinic visit. Strength of 11 movements was measured via dynamometry at each clinic visit. Patient-reported function was measured via the Neuromuscular Symptom Score (NSS). Generalised linear modelling, adjusted for disease duration, was carried out to identify associations between strength and function (NSS). Pinch, knee extension and ankle dorsiflexion strength measurements were analysed. Modelling was carried out separately for male and female cohorts.

Results

Data of 75 participants (47% female) was analysed. A total of 591 measurements were taken. Median age at time of IBM diagnosis was 68.8 years. Median baseline NSS score was 45 (IQR 37, 54) for the male cohort and 40 (IQR 29, 45) for the female cohort. The median disease duration of the study cohort was 2.6 years. Reduced function (NSS) was significantly associated with reduced pinch, knee extension and ankle dorsiflexion strength in the male cohort only (Table 1). No significant associations were observed in the female cohort.

Conclusion

This is the first study to demonstrate that the progression of weakness, in the characteristic muscle groups affected in IBM, impacts on function differently in men and women. These results illustrate the importance of functional assessment in patients with IBM and the importance of focused physiotherapy upon function-dependent muscle groups. Further, potential gender-based differences of weakness-related function in IBM should be considered when designing clinical trials.

Disclosures

J. Williams None. A. Oldroyd None. J. Lilleker None. H. Chinoy None. J. Miller None.

THUR 153 Antibodies against the voltage-gated potassium channel complex

Voltage-gated potassium channel (VGKC) complex antibodies have been associated with a spectrum of presentations including peripheral nerve hyperexcitability (PNH), Morvan’s syndrome, autoimmune encephalopathy, epilepsy and recently psychosis.

We retrospectively reviewed the medical records of 70 patients from the Greater Manchester Neuroscience Centre, who had tested positive for VGKC-complex antibodies between 2012 and 2015 to identify the clinical relevance of positive results.

The majority were diagnosed with autoimmune encephalopathy(19) followed by epilepsy(14), psychosis(10) and PNH(6). The remaining fifteen had other neurological presentations and six had no primary neurological disorder. 39/70 patients who had antibody titres>400 pM, were diagnosed with autoimmune encephalopathy(19), epilepsy(9), psychosis(4), PNH(3) and other disorders(4). 24/39 patients, who received treatment with one or a combination of corticosteroids, intravenous immunoglobulins, cyclophosphamide, plasma exchange, azathioprine or rituximab, had a diagnosis of autoimmune encephalopathy(18), epilepsy(2), psychosis(2) and malignancy(2). 16/24 were treatment responsive. 3/31 patients with lower titres were also treated, but only one with the classic phenotype (PNH) responded to treatment.

The classic phenotype often had a titre >400 pM. PNH may have a titre ≤400 pM. The patients without classic presentations typically had titres≤400 pM. Consistent with previous studies, clinical phenotyping and antibody titre helped to determine the relevance of VGKC-complex antibodies.

Missense mutation in the ITPR1 gene presenting with ataxic cerebral palsy: Description of an affected family and literature review

The inositol 1,4,5-triphosphate receptor type 1 (ITPR1) gene on chromosome 3 belongs to a family of genes encoding intracellular calcium channel proteins. Such channels are located primarily within the endoplasmic reticular membrane and release Ca²⁺, an intracellular messenger, which governs numerous intracellular and extracellular functions. We report a family with infantile-onset cerebellar ataxia with delayed motor development and intellectual disability caused by a heterozygous c.805C>T, p.Arg269Trp missense mutation in ITPR1. Both affected family members had postural tremor, hypotonia and dysarthria, but neither had pyramidal signs. Their neuroimaging revealed cerebellar atrophy. Several neurological conditions have been associated with ITPR1 mutations, such as spinocerebellar ataxia type 15 and Gillespie syndrome, and the phenotype may vary according to the location and type of mutations. Spinocerebellar ataxia type 15 is an autosomal dominant disorder, which causes late onset pure cerebellar ataxia. Gillespie syndrome is characterised by bilateral iris hypoplasia, congenital hypotonia, non-progressive ataxia and cerebellar atrophy. In this report, we provide a detailed phenotypic description of a family with a missense mutation in ITPR1. This mutation has only been reported once before. We also provide a literature review of the various phenotypes associated with ITPR1 gene.

Idiopathic inflammatory myopathies - a guide to subtypes, diagnostic approach and treatment

The idiopathic inflammatory myopathies are a group of conditions characterised by inflammation of muscles (myositis) and other body systems. The diagnosis can be challenging because of the many potential clinical features and extra-muscular manifestations, which may be seemingly unrelated. An accurate diagnosis requires up-to-date understanding of the clinical manifestations, different clinical subtypes and appropriate interpretation of investigations, including newly described serological subtypes.This review will detail the approach to the diagnosis of an idiopathic inflammatory myopathy, based on up-to-date knowledge. The recently updated classification criteria and treatment options will also be described.

Selected aspects of the current management of myositis

The idiopathic inflammatory myopathies (IIM) are a rare and heterogeneous group of acquired autoimmune muscle disorders, often referred to as 'myositis'. Clinical assessment, together with muscle biopsy findings and autoantibody status are key factors to consider when making a diagnosis of IIM, and in stratification of the 'IIM spectrum' into disease subgroups. Treatment stratified according to serotype (and in the future, likely also genotype) is increasingly being used to take account of the heterogeneity within the IIM spectrum. Subgroup classification is also important in terms of monitoring for complications, such as malignancy and interstitial lung disease. Disease monitoring should include the use of standardized tools such as the IMACS disease activity outcome measures. Other tools such as muscle MRI can be useful in identifying areas of active muscle inflammation. Treatment outcomes in IIM remain unsatisfactory. The evidence base to guide treatment decisions is remarkably limited. In addition to muscle inflammation, a number of noninflammatory cell-mediated mechanisms may contribute to weakness and disability, and for which no specific treatments are currently available.

Neurological manifestations of influenza infection in children and adults: results of a National British Surveillance Study

BACKGROUND

The emergence of influenza A(H1N1) 2009 was met with increased reports of associated neurological manifestations. We aimed to describe neurological manifestations of influenza in adults and children in the United Kingdom that presented at this time.

METHODS

A 2-year surveillance study was undertaken through the British adult and pediatric neurological surveillance units from February 2011. Patients were included if they met clinical case definitions within 1 month of proven influenza infection.

RESULTS

Twenty-five cases were identified: 21 (84%) in children and 4 (16%) in adults. Six (29%) children had preexisting neurological disorders. Polymerase chain reaction of respiratory secretions identified influenza A in 21 (81%; 20 of which [95%] were H1N1) and influenza B in 4 (15%). Twelve children had encephalopathy (1 with movement disorder), 8 had encephalitis, and 1 had meningoencephalitis. Two adults had encephalopathy with movement disorder, 1 had encephalitis, and 1 had Guillain-Barré syndrome. Seven individuals (6 children) had specific acute encephalopathy syndromes (4 acute necrotizing encephalopathy, 1 acute infantile encephalopathy predominantly affecting the frontal lobes, 1 hemorrhagic shock and encephalopathy, 1 acute hemorrhagic leukoencephalopathy). Twenty (80%) required intensive care, 17 (68%) had poor outcome, and 4 (16%) died.

CONCLUSIONS

This surveillance study described a cohort of adults and children with neurological manifestations of influenza. The majority were due to H1N1. More children than adults were identified; many children had specific encephalopathy syndromes with poor outcomes. None had been vaccinated, although 8 (32%) had indications for this. A modified classification system is proposed based on our data and the increasing spectrum of recognized acute encephalopathy syndromes.