Epidemiological and cohort study finds no association between COVID-19 and Guillain-Barré syndrome.

Reports of Guillain-Barré syndrome (GBS) have emerged during the Coronavirus disease 2019 (COVID-19) pandemic. This epidemiological and cohort study sought to investigate any causative association between COVID-19 infection and GBS. The epidemiology of GBS cases reported to the UK National Immunoglobulin Database was studied from 2016 to 2019 and compared to cases reported during the COVID-19 pandemic. Data were stratified by hospital trust and region, with numbers of reported cases per month. UK population data for COVID-19 infection were collated from UK public health bodies. In parallel, but separately, members of the British Peripheral Nerve Society prospectively reported incident cases of GBS during the pandemic at their hospitals to a central register. The clinical features, investigation findings and outcomes of COVID-19 (definite or probable) and non-COVID-19 associated GBS cases in this cohort were compared. The incidence of GBS treated in UK hospitals from 2016 to 2019 was 1.65-1.88 per 100 000 individuals per year. GBS incidence fell between March and May 2020 compared to the same months of 2016-19. GBS and COVID-19 incidences during the pandemic also varied between regions and did not correlate with one another (r = 0.06, 95% confidence interval: -0.56 to 0.63, P = 0.86). In the independent cohort study, 47 GBS cases were reported (COVID-19 status: 13 definite, 12 probable, 22 non-COVID-19). There were no significant differences in the pattern of weakness, time to nadir, neurophysiology, CSF findings or outcome between these groups. Intubation was more frequent in the COVID-19 affected cohort (7/13, 54% versus 5/22, 23% in COVID-19-negative) attributed to COVID-19 pulmonary involvement. Although it is not possible to entirely rule out the possibility of a link, this study finds no epidemiological or phenotypic clues of SARS-CoV-2 being causative of GBS. GBS incidence has fallen during the pandemic, which may be the influence of lockdown measures reducing transmission of GBS inducing pathogens such as Campylobacter jejuni and respiratory viruses.

Cost-minimisation analysis of plasma exchange versus IVIg in the treatment of autoimmune neurological conditions.

BACKGROUND: Plasma exchange (PLEX) is an effective treatment for antibody-mediated neurological disorders and has been shown to be equally efficacious to intravenous immunoglobulin (IVIg) with comparable adverse event profiles. IVIg has traditionally been the preferred treatment option due to its ease of use. However, advancing technology has allowed PLEX to be performed with a centrifugal system via peripheral access as opposed to central access via a membrane filter. METHODS: We prospectively collected data from a cohort of patients who underwent PLEX at the Wessex Neurological Centre, UK, to perform a cost-minimisation analysis comparing PLEX to IVIg, the standard of care, between May 2019 and May 2020. Data obtained included indication, admission type (inpatient, daycase or intensive care), access (peripheral or central), number of PLEX cycles, exchange volume, patient weight, complications and clinical outcomes. The cost of PLEX delivered in an outpatient setting for an average 80kg person was calculated and compared to the equivalent cost of delivering IVIg by means of a cost-minimization model. RESULTS: The provision of PLEX was roughly half as costly when compared to what it would have been for IVIg (£886 per exchange vs £1778 per infusion or £4432 per cycle of 5 exchanges vs £8890 per cycle of 5 infusions). Our cohort included a total of 44 patients who received a total of 357 PLEX exchanges during the 12-month period (the majority of which were in a daycase setting). We calculated an annual cost saving for PLEX over IVIg of £318,589. The robustness of this result was confirmed by a one-way deterministic sensitivity analysis, showing the cost-effectiveness of PLEX. CONCLUSION: Our findings demonstrate that PLEX is more cost-effective than IVIg in this setting. Our study supports the economic case for development of plasma exchange centres in regional neurology units, a case made all the more relevant in the context of constrained supplies of IVIg.

Evaluation and improvement of the National Early Warning Score (NEWS2) for COVID-19: a multi-hospital study.

BACKGROUND: The National Early Warning Score (NEWS2) is currently recommended in the UK for the risk stratification of COVID-19 patients, but little is known about its ability to detect severe cases. We aimed to evaluate NEWS2 for the prediction of severe COVID-19 outcome and identify and validate a set of blood and physiological parameters routinely collected at hospital admission to improve upon the use of NEWS2 alone for medium-term risk stratification. METHODS: Training cohorts comprised 1276 patients admitted to King's College Hospital National Health Service (NHS) Foundation Trust with COVID-19 disease from 1 March to 30 April 2020. External validation cohorts included 6237 patients from five UK NHS Trusts (Guy's and St Thomas' Hospitals, University Hospitals Southampton, University Hospitals Bristol and Weston NHS Foundation Trust, University College London Hospitals, University Hospitals Birmingham), one hospital in Norway (Oslo University Hospital), and two hospitals in Wuhan, China (Wuhan Sixth Hospital and Taikang Tongji Hospital). The outcome was severe COVID-19 disease (transfer to intensive care unit (ICU) or death) at 14 days after hospital admission. Age, physiological measures, blood biomarkers, sex, ethnicity, and comorbidities (hypertension, diabetes, cardiovascular, respiratory and kidney diseases) measured at hospital admission were considered in the models. RESULTS: A baseline model of 'NEWS2 + age' had poor-to-moderate discrimination for severe COVID-19 infection at 14 days (area under receiver operating characteristic curve (AUC) in training cohort = 0.700, 95% confidence interval (CI) 0.680, 0.722; Brier score = 0.192, 95% CI 0.186, 0.197). A supplemented model adding eight routinely collected blood and physiological parameters (supplemental oxygen flow rate, urea, age, oxygen saturation, C-reactive protein, estimated glomerular filtration rate, neutrophil count, neutrophil/lymphocyte ratio) improved discrimination (AUC = 0.735; 95% CI 0.715, 0.757), and these improvements were replicated across seven UK and non-UK sites. However, there was evidence of miscalibration with the model tending to underestimate risks in most sites. CONCLUSIONS: NEWS2 score had poor-to-moderate discrimination for medium-term COVID-19 outcome which raises questions about its use as a screening tool at hospital admission. Risk stratification was improved by including readily available blood and physiological parameters measured at hospital admission, but there was evidence of miscalibration in external sites. This highlights the need for a better understanding of the use of early warning scores for COVID.

Plasma exchange in neurological disease.

Plasma exchange is a highly efficient technique to remove circulating autoantibodies and other humoral factors rapidly from the vascular compartment. It was the first effective acute treatment for peripheral disorders such as Guillain-Barré syndrome and myasthenia gravis before intravenous immunoglobulin became available. The recent recognition of rapidly progressive severe antibody-mediated central nervous system disorders, such as neuromyelitis optica spectrum disorders and anti-N-methyl-D-aspartate-receptor encephalitis, has renewed interest in using plasma exchange for their acute treatment also. In this review we explain the principles and technical aspects of plasma exchange, review its current indications, and discuss the implications for its provision in the UK.

Refractory CIDP with chronic lymphocytic leukaemia responding to chemoimmunotherapy.

Chronic inflammatory demyelinating polyneuropathy (CIDP) has a variable clinical course with 15% remaining refractory to treatment. We report a woman with severe refractory CIDP and coexisting chronic lymphocytic leukaemia (CLL) who improved dramatically after chemoimmunotherapy appropriate for the CLL, including rituximab. A subsequent CIDP relapse after 15 months responded again to similar treatment, and the improvement has been maintained with 3-monthly rituximab infusions as sole ongoing therapy. The case suggests that CIDP refractory to conventional treatment may have associated pathology, in this case haematological malignancy, and that treating the malignancy can effectively treat the CIDP.

Reversible cerebellar oedema secondary to profound hypomagnesaemia.

Magnesium is the second most abundant intracellular cation. Deficiency can cause several neurological complications, including cerebellar syndromes, with various MRI findings. These include cerebellar oedema, presumably through a similar mechanism to that in posterior reversible encephalopathy syndrome (PRES). People particularly vulnerable to deficiency include those with high alcohol consumption, excessive loss due to gastrointestinal pathology and those taking certain medications, including proton pump inhibitors. We report three patients with cerebellar syndromes associated with hypomagnesaemia. These cases support the previously reported association between hypomagnesaemia and reversible cerebellar dysfunction and illustrate the range of potential presentations. They highlight an uncommon but treatable cause of cerebellar ataxia that may present to acute neurological liaison services.

Lyme disease: diagnosis and management.

Lyme disease (borreliosis) is a tick-borne bacterial infection caused by the spirochaete Borrelia burgdoferi, transmitted by hard-backed Ixodes ticks. Actual numbers of cases are increasing and it appears that the distribution across the UK is widening; however, it occurs most frequently in area of woodland, with temperate climate. It typically presents in mid to late summer. Lyme disease is a multisystem disease. The nervous system is the second most commonly affected system after the skin. Other systemic manifestations, such as carditis, keratitis, uveitis and inflammatory arthritis, rarely occur in European Lyme disease. In 2018, the National Institute for Health and Care Excellence has updated its guidelines on the diagnosis and management of Lyme disease. Here, we highlight important aspects of this guidance and provide a more detailed review of the clinical spectrum of neuroborreliosis, illustrated by cases we have seen.

Corticosteroid-responsive focal granulomatous herpes simplex type-1 encephalitis in adults.

We describe corticosteroid-responsive focal granulomatous encephalitis as a manifestation of herpes simplex virus (HSV) type 1 disease in the brain: something easily missed and easily treated. Two adult cases presented with cognitive symptoms progressing over weeks, despite aciclovir treatment. Brain imaging showed temporal lobe abnormalities, with gadolinium enhancement but no abnormal diffusion restriction. HSV-1 PCR analysis was negative in cerebrospinal fluid (CSF) but positive in brain biopsies, which showed vasocentric granulomatous inflammation. Paired blood and CSF samples showed intrathecal synthesis of HSV-1 type-specific IgG. The patients improved clinically only after immunosuppression. Despite profound cognitive impairment at their clinical nadir, both patients recovered fully. We suggest that, at least in a subset of patients with HSV-1 encephalitis, adjunctive corticosteroid treatment is critical to improve the outcome of the disease.

'The worm that got away': parainfectious atypical optic neuritis associated with schistosomiasis infection.

Although optic neuritis is commonly associated with multiple sclerosis, patients with atypical optic neuritis require further investigations to exclude other associated conditions. We report a woman presenting with cough, fatigue, atypical optic neuritis with chiasmitis. She responded partially to corticosteroids and we subsequently found she had a ground-glass lung nodule. Follow-up CT scan of thorax at 12 months showed new parenchymal lung lesions that suggested schistosomiasis. Further questioning by a respiratory physician identified, in retrospect, a previous exposure history; serological testing confirmed schistosoma infection. She was treated with praziquantel and slowly improved clinically, with radiological improvement in the optic chiasm, regression of the parenchymal lung lesions but with the ground glass nodule unchanged. We diagnosed parainfectious optic neuritis associated with schistosomiasis, based upon exposure history, serological confirmation and radiological features, together with the response to treatment, and having excluded other causes of an atypical optic neuritis.

Comparison of IVIg and TPE efficacy in the treatment of neurological disorders: a systematic literature review.

Background: Intravenous immunoglobulin (IVIg) and therapeutic plasma exchange (TPE) are among the main immunotherapies for neurological disorders. Their benefit is greatest in immune-mediated conditions, but their distinct efficacy cannot be simply explained. Objectives: This review aimed to systematically identify studies comparing the efficacy of TPE and IVIg treatments for selected autoimmune neurological disorders and identify optimal therapies for each condition. Data Sources and Methods: PubMed, MEDLINE and Embase databases were searched for original publications from 1990 to 2021. Additional publications were identified via expert recommendations. Conference abstracts older than 2017, review articles and articles without information on TPE and IVIg comparison in title and abstract were excluded. Risks of bias were descriptively addressed, without a meta-analysis. Results: Forty-four studies were included on Guillain-Barré syndrome (20 studies - 12 adult, 5 paediatric, 3 all ages), myasthenia gravis (11 studies -8 adult, 3 paediatric), chronic immune-mediated polyradiculoneuropathy (3 studies -1 adult, 2 paediatric), encephalitis (1 study in adults), neuromyelitis optica spectrum disorders (5 studies -2 adult, 3 all ages) and other conditions (4 studies - all ages). TPE and IVIg were mostly similarly efficacious, measured by clinical outcomes and disease severity scores. Some studies recommended IVIg as easy to administer. TPE procedures, however, have been simplified and the safety has been improved. TPE is currently recommended for management of neuromyelitis optica spectrum disorder relapses and some myasthenia gravis subtypes, in which rapid removal of autoantibodies is crucial. Conclusion: Despite some limitations (e.g. the low evidence levels), this review provides an extensive 30-year-long overview of treatments for various conditions. Both IVIg and TPE are usually comparably efficacious options for autoimmune neurological disorders, with few exceptions. Treatment choices should be patient-tailored and based on available clinical resources. Better designed studies are needed to provide higher-level quality of evidence regarding clinical efficacy of TPE and IVIg treatments.

Desminopathy presenting as late onset bilateral facial weakness, with diagnosis supported by lower limb MRI.

A 63 year old male presented with a 20 year history of facial weakness and several years of nasal regurgitation and dysphonia. Examination revealed bilateral facial weakness with nasal speech. Serum creatine kinase was 918 U/L. Neurophysiological studies suggested a myopathy and biopsy of the left vastus lateralis showed serpentine basophilic inclusions in the sarcoplasm and strong oxidative enzyme activity suggesting mitochondria accumulation. The muscle MRI showed selective fatty replacement within semitendinosus, gastrocnemius and soleus indicative of a desminopathy. A heterozygous missense variant c.17C>G (p.Ser6Trp) was identified within DES, predicted to be pathogenic in silico and previously described in a family with distal limb weakness. There are no previous case reports of desminopathy presenting with facial weakness, to our knowledge. Diagnosis was suggested following myoimaging of clinically unaffected muscles. Our study highlights the importance of muscle MRI in the diagnostic evaluation of muscle disease and further expands the known phenotypic heterogeneity of desminopathies.

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.

Measuring quality of life in ALS/MND: validation of the WHOQOL-BREF.

Objectives: The World Health Organization Quality of Life-BREF Scale (WHOQOL-BREF) is a generic QOL measure with four domains covering Physical, Psychological, Social and Environment. Providing the opportunity to contrast QoL with other conditions, or with population norms, the current study had three aims: 1) can the established domains of the WHOQOL-BREF be validated within a large ALS/MND population; 2) can a total score be validated and 3) can they provide interval level measurement? Methods: Data were obtained from the Trajectories of Outcomes in Neurological Conditions study. Internal construct validity was determined by fit of the data to the Rasch measurement model. Results: 636 participants with ALS/MND were included. All domains, except the Social domain, showed satisfactory fit to the Rasch model. All were unidimensional, and showed no Differential Item Functioning by age, gender, or onset type. Finally, a total score was validated from a bi-factor perspective. Conclusions: The WHOQOL-BREF is valid for use in populations with ALS/MND and can be analyzed to yield interval level measurement: It offers a range of domains that reflect QOL, which can be used for parametric analysis and for comparison with other conditions or general populations, two advantages for its inclusion as a trial outcome measure and for observational studies.

The relationships between symptoms, disability, perceived health and quality of life in amyotrophic lateral sclerosis/motor neuron disease.

Objectives: Using the Wilson and Cleary model linking clinical variables to quality of life, we explored the associations between physical and psychological factors, disability, perceived health and quality of life in ALS/MND. Methods: The ongoing UK study of Trajectories of Outcomes in Neurological Conditions (TONiC) recruited participants with ALS/MND to complete a questionnaire pack including demographic factors and several patient reported outcome measures (PROMs); a clinician provided data on disease onset type and duration since diagnosis. All PROMs were transformed from ordinal raw scores to interval-scaled latent estimates via the Rasch measurement model. Results: Data from 636 patients were analyzed; mean age 65.1 years (SD 10.7), 61.3% male. Median duration since diagnosis was 11.2 months (IQR 4.6-29.9; range 0.4-295.9 months); 67.3% had limb and 27.3% bulbar onset disease. Symptoms such as breathlessness and fatigue, along with most domains of activity limitations, were shown to vary by onset type. A series of models illustrated the importance of physical functioning and anxiety upon quality of life, with breathlessness and fatigue having indirect effects. The models were invariant for gender and onset type. Conclusions: This large study highlights the importance of functional status and anxiety as key variables influencing quality of life in ALS/MND. The nature and diversity of factors, both physical and psychological, which have been shown to influence the quality of life of people with ALS/MND provide strong evidence in support of the widespread implementation of multidisciplinary care.

A study of the utility of azathioprine metabolite testing in myasthenia gravis.

Myasthenia gravis (MG) is an autoimmune neuromuscular disorder characterised by fatigable voluntary skeletal muscle weakness. The underlying pathogenesis is complex involving adaptive autoimmune responses. Azathioprine remains a first line broad acting immunosuppressant for MG. Due to varied clinical responses to azathioprine we aimed to investigate the relationship between azathioprine metabolites and symptom control. Mild correlations between Quantitative Myasthenia Gravis Score (QMG) vs. 6-thioguanine nucleotides (R=-0.317 p=0.186) and QMG vs. lymphocyte count (R=0.402 p=0.08) were found. Azathioprine metabolite measurement should be considered in MG patients with; pancytopenia, deranged liver function or recurrent infections.

Differential diagnosis of finger drop.

Finger drop is a useful clinical sign which is easy to elicit. This article presents a logical approach for assessing patients with finger drop and outlines the important causes, and how to differentiate them. Patients with finger drop may present either to orthopedic surgeons or to neurologists, and both specialists should be aware of important diagnoses in their complementary fields.

Pathogenic autoantibodies in the lambert-eaton myasthenic syndrome.

Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disorder of neuromuscular transmission in which antibodies are directed against voltage-gated calcium channels (VGCCs). We studied the action of LEMS immunoglobulin G (IgG) on cloned human VGCCs stably transfected into human embryonic kidney cells (HEK293). All LEMS IgGs tested bound to the surface of the P/Q-type VGCC cell line and caused a significant reduction in whole-cell calcium currents in these cells. By contrast, only 2 out of 6 IgGs bound extracellularly to the N-type VGCC cell line, and none of the LEMS IgGs tested was able to reduce whole-cell calcium currents in these cells. We used this apparent specificity of LEMS IgG for the P/Q-type VGCC to investigate the action of these IgGs on model systems where a number of different VGCC populations exist in equilibrium. LEMS IgG caused a significant downregulation in the omega-agatoxin IVA-sensitive P/Q-type VGCCs of cultured rat cerebellar neurons, but this was accompanied by a concomitant rise in the "resistant" R-type VGCCs. By using the passive transfer model of LEMS, similar results were observed at the mouse neuromuscular junction, where a significant reduction in P/Q-type VGCCs was paralleled by an increase in L- and R-type VGCCs. These results demonstrate an unexpected plasticity in the expression of VGCCs in mammalian neurons and may represent a mechanism by which the pathogenic effects of LEMS IgG are reduced.