Modified Erasmus GBS Respiratory Insufficiency Score: a simplified clinical tool to predict the risk of mechanical ventilation in Guillain-Barré syndrome.

BACKGROUND: This study aimed to determine the clinical and diagnostic factors associated with mechanical ventilation (MV) in Guillain-Barré syndrome (GBS) and to simplify the existing Erasmus GBS Respiratory Insufficiency Score (EGRIS) for predicting the risk of MV. METHODS: Data from the first 1500 patients included in the prospective International GBS Outcome Study (IGOS) were used. Patients were included across five continents. Patients <6 years and patients from Bangladesh were excluded. Univariable logistic and multivariable Cox regression were used to determine which prespecified clinical and diagnostic characteristics were associated with MV and to predict the risk of MV at multiple time points during disease course. RESULTS: 1133 (76%) patients met the study criteria. Independent predictors of MV were a shorter time from onset of weakness until admission, the presence of bulbar palsy and weakness of neck flexion and hip flexion. The modified EGRIS (mEGRIS) was based on these factors and accurately predicts the risk of MV with an area under the curve (AUC) of 0.84 (0.80-0.88). We internally validated the model within the full IGOS cohort and within separate regional subgroups, which showed AUC values of 0.83 (0.81-0.88) and 0.85 (0.72-0.98), respectively. CONCLUSIONS: The mEGRIS is a simple and accurate tool for predicting the risk of MV in GBS. Compared with the original model, the mEGRIS requires less information for predictions with equal accuracy, can be used to predict MV at multiple time points and is also applicable in less severely affected patients and GBS variants. Model performance was consistent across different regions.

Association of mannose-binding lectin 2 gene polymorphisms with Guillain-Barré syndrome.

Complement activation plays a critical role in the pathogenesis of Guillain-Barré syndrome (GBS), a debilitating immune-mediated neuropathy. Mannose-binding lectin (MBL) is a complement activation factor of lectin pathway which as genetic host factor may influence the susceptibility or severity of GBS. We investigated the frequency of MBL2 promoter (- 550H/L and - 221X/Y) and functional region (exon 1 A/O) polymorphisms and their association with disease susceptibility, clinical features and serum MBL among GBS patients (n = 300) and healthy controls (n = 300) in Bangladesh. The median patient age was 30 years (IQR: 18-42; males, 68%). MBL2 polymorphisms were not significantly associated with GBS susceptibility compared to healthy controls. HL heterozygosity in GBS patients was significantly associated with mild functional disability at enrolment (P = 0.0145, OR, 95% CI 2.1, 1.17-3.82). The HY, YA, HA and HYA heterozygous haplotypes were more common among mildly affected (P = 0.0067, P = 0.0086, P = 0.0075, P = 0.0032, respectively) than severely affected patients with GBS. Reduced serum MBL was significantly associated with the LL, OO and no HYA variants and GBS disease severity. No significant association was observed between MBL2 polymorphisms and electrophysiological variants, recent Campylobacter jejuni infection or anti-ganglioside (GM1) antibody responses in GBS. In conclusion, MBL2 gene polymorphisms are related to reduced serum MBL and associated with the severity of GBS.

International Validation of the Erasmus Guillain-Barré Syndrome Respiratory Insufficiency Score.

OBJECTIVE: This study aimed to validate the Erasmus Guillain-Barré Syndrome Respiratory Insufficiency Score in the International Guillain-Barré Syndrome Outcome Study cohort, and to improve its performance and region-specificity. METHODS: We examined data from the first 1,500 included patients, aged ≥6 years and not ventilated prior to study entry. Patients with a clinical variant or mild symptoms were also included. Outcome was mechanical ventilation within the first week from study entry. Model performance was assessed regarding the discriminative ability (area under the receiver operating characteristic curve) and the calibration (observed vs predicted probability of mechanical ventilation), in the full cohort and in Europe/North America and Asia separately. We recalibrated the model to improve its performance and region-specificity. RESULTS: In the group of 1,023 eligible patients (Europe/North America n = 842, Asia n = 104, other n = 77), 104 (10%) required mechanical ventilation within the first week from study entry. Area under the curve values were ≥0.80 for all validation subgroups. Mean observed proportions of mechanical ventilation were lower than predicted risks: full cohort 10% versus 21%, Europe/North America 9% versus 21%, and Asia 17% versus 23%. After recalibration, predicted risks for the full cohort and Europe/North America corresponded to observed proportions. INTERPRETATION: This prospective, international cohort study validated the Erasmus Guillain-Barré Syndrome Respiratory Insufficiency Score, and showed that the model can be used in the full spectrum of Guillain-Barré syndrome patients. In addition, a more accurate, region-specific version of the model was developed for patients from Europe/North America. ANN NEUROL 2022;91:521-531.

Electrodiagnosis of Guillain-Barre syndrome in the International GBS Outcome Study: Differences in methods and reference values.

OBJECTIVE: To describe the heterogeneity of electrodiagnostic (EDx) studies in Guillain-Barré syndrome (GBS) patients collected as part of the International GBS Outcome Study (IGOS). METHODS: Prospectively collected clinical and EDx data were available in 957 IGOS patients from 115 centers. Only the first EDx study was included in the current analysis. RESULTS: Median timing of the EDx study was 7 days (interquartile range 4-11) from symptom onset. Methodology varied between centers, countries and regions. Reference values from the responding 103 centers were derived locally in 49%, from publications in 37% and from a combination of these in the remaining 15%. Amplitude measurement in the EDx studies (baseline-to-peak or peak-to-peak) differed from the way this was done in the reference values, in 22% of motor and 39% of sensory conduction. There was marked variability in both motor and sensory reference values, although only a few outliers accounted for this. CONCLUSIONS: Our study showed extensive variation in the clinical practice of EDx in GBS patients among IGOS centers across the regions. SIGNIFICANCE: Besides EDx variation in GBS patients participating in IGOS, this diversity is likely to be present in other neuromuscular disorders and centers. This underlines the need for standardization of EDx in future multinational GBS studies.

Predicting Outcome in Guillain-Barré Syndrome: International Validation of the Modified Erasmus GBS Outcome Score.

BACKGROUND AND OBJECTIVES: The clinical course and outcome of the Guillain-Barré syndrome (GBS) are diverse and vary among regions. The modified Erasmus GBS Outcome Score (mEGOS), developed with data from Dutch patients, is a clinical model that predicts the risk of walking inability in patients with GBS. The study objective was to validate the mEGOS in the International GBS Outcome Study (IGOS) cohort and to improve its performance and region specificity. METHODS: We used prospective data from the first 1,500 patients included in IGOS, aged ≥6 years and unable to walk independently. We evaluated whether the mEGOS at entry and week 1 could predict the inability to walk unaided at 4 and 26 weeks in the full cohort and in regional subgroups, using 2 measures for model performance: (1) discrimination: area under the receiver operating characteristic curve (AUC) and (2) calibration: observed vs predicted probability of being unable to walk independently. To improve the model predictions, we recalibrated the model containing the overall mEGOS score, without changing the individual predictive factors. Finally, we assessed the predictive ability of the individual factors. RESULTS: For validation of mEGOS at entry, 809 patients were eligible (Europe/North America [n = 677], Asia [n = 76], other [n = 56]), and 671 for validation of mEGOS at week 1 (Europe/North America [n = 563], Asia [n = 65], other [n = 43]). AUC values were >0.7 in all regional subgroups. In the Europe/North America subgroup, observed outcomes were worse than predicted; in Asia, observed outcomes were better than predicted. Recalibration improved model accuracy and enabled the development of a region-specific version for Europe/North America (mEGOS-Eu/NA). Similar to the original mEGOS, severe limb weakness and higher age were the predominant predictors of poor outcome in the IGOS cohort. DISCUSSION: mEGOS is a validated tool to predict the inability to walk unaided at 4 and 26 weeks in patients with GBS, also in countries outside the Netherlands. We developed a region-specific version of mEGOS for patients from Europe/North America. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that the mEGOS accurately predicts the inability to walk unaided at 4 and 26 weeks in patients with GBS. TRIAL REGISTRATION INFORMATION: NCT01582763.

Impact of Covid-19 on the therapeutic plasma exchange service within the South East Asian region: Consensus recommendations and global perspectives.

INTRODUCTION: Therapeutic plasma exchange (TPE) for neuroimmunological disorders has played an increasingly important role within the Southeast Asian (SEA) region. The South East Asian Therapeutic Plasma exchange Consortium (SEATPEC) was formed in 2018 to promote education and research on TPE within the region. The advent of the Covid-19 pandemic has produced challenges for the development and expansion of this service. METHODOLOGY: A qualitative and semi-quantitative questionnaire-based survey was conducted by SEATPEC member countries from January to June 2020 (Phase 1) and then from July 2020 to January 2021 in (Phase 2) to assess the impact of Covid-19 on regional TPE. OBJECTIVES: The study's main objectives were to explore the challenges experienced and adaptations/adjustments taken by SEATPEC countries in order to continue safe and efficient TPE during the Covid-19 pandemic. RESULTS: The pandemic was found to disrupt the delivery of TPE services in all SEATPEC countries. Contributing factors were multifactorial due to overstretched medical services, staff shortages, quarantines and redeployments, fear of acquiring Covid-19, movement restriction orders, and patient's psychological fear of attending hospitals/testing for Covid-19. All SEATPEC countries practiced careful stratification of cases for TPE (electives vs emergencies, Covid-19 vs non-Covid-19 cases). SEATPEC countries had to modify TPE treatment protocols to include careful preprocedure screening of patient's for Covid-19, use of personal protective equipment (PPE) and post-TPE sanitization of machines and TPE suites. CONCLUSION: Based on the responses of the survey, SEATPEC countries produced a consensus statement with five recommendations for safe and effective TPE within the region.

[Evidence based guidelines. Diagnosis and management of Guillain-Barré syndrome in ten steps]. / Guía basada en la evidencia. Diagnóstico y manejo del síndrome de Guillain-Barré en diez pasos.

Guillain-Barré syndrome (GBS) is a rare, but potentially fatal, immune-mediated disease of the peripheral nerves and nerve roots that is usually triggered by infections. The incidence of GBS can therefore increase during outbreaks of infectious diseases, as was seen during the Zika virus epidemics in 2013 in French Polynesia and in 2015 in Latin America. Diagnosis and management of GBS can be complicated as its clinical presentation and disease course are heterogeneous, and no international clinical guidelines are currently available. To support clinicians, especially in the context of an outbreak, we have developed a globally applicable guideline for the diagnosis and management of GBS. The guideline is based on current literature and expert consensus, and has a ten-step structure to facilitate its use in clinical practice. We first provide an introduction to the diagnostic criteria, clinical variants and differential diagnoses of GBS. The ten steps then cover early recognition and diagnosis of GBS, admission to the intensive care unit, treatment indication and selection, monitoring and treatment of disease progression, prediction of clinical course and outcome, and management of complications and sequelae.

El síndrome de Guillain-Barré (SGB) es una enfermedad inmunológica del nervio periférico y las raíces nerviosas, poco frecuente, potencialmente mortal y que suele desencadenarse por infecciones. La incidencia del SGB puede aumentar durante el brote de enfermedades infecciosas, tal como se observó en las epidemias del virus Zika en la Polinesia Francesa en 2013 y en América Latina en 2015. El diagnóstico y el manejo clínico del SGB pueden ser complicados ya que su presentación y el curso de la enfermedad son heterogéneos, y actualmente no se cuenta con guías clínicas internacionales. Para respaldar a los médicos, especialmente en el contexto de un brote de una enfermedad infecciosa, hemos desarrollado una guía clínica aplicable en todo el mundo para el diagnóstico y el tratamiento del SGB. La guía se basa en literatura actualizada y el consenso de expertos, y tiene una estructura de diez pasos para facilitar su uso en la práctica clínica. Inicialmente, brindamos una introducción a los criterios de diagnóstico, variantes clínicas y diagnósticos diferenciales del SGB. Los diez pasos luego abordan el reconocimiento y el diagnóstico temprano del SGB, la admisión a la unidad de cuidados intensivos, indicación y selección de tratamiento, seguimiento y tratamiento de la progresión de la enfermedad, predicción del curso clínico, resultados y tratamiento de complicaciones y secuelas.

Guía basada en la evidencia. Diagnóstico y manejo del síndrome de Guillain-Barré en diez pasos / Evidence based guidelines. Diagnosis and management of Guillain-Barré syndrome in ten steps

Resumen El síndrome de Guillain-Barré (SGB) es una enfermedad inmunológica del nervio periférico y las raíces nerviosas, poco frecuente, potencialmente mortal y que suele desencadenarse por infecciones. La incidencia del SGB puede aumentar durante el brote de enfermedades infecciosas, tal como se observó en las epidemias del virus Zika en la Polinesia Francesa en 2013 y en América Latina en 2015. El diagnóstico y el manejo clínico del SGB pueden ser complicados ya que su presentación y el curso de la enfermedad son heterogéneos, y actualmente no se cuenta con guías clínicas internacionales. Para respaldar a los médicos, especialmente en el contexto de un brote de una enfermedad infecciosa, hemos desarrollado una guía clínica aplicable en todo el mundo para el diagnóstico y el tratamiento del SGB. La guía se basa en literatura actualizada y el consenso de expertos, y tiene una estructura de diez pasos para facilitar su uso en la práctica clínica. Inicialmente, brindamos una introducción a los criterios de diagnóstico, variantes clínicas y diagnósticos diferenciales del SGB. Los diez pasos luego abordan el reconocimiento y el diagnóstico temprano del SGB, la admisión a la unidad de cuidados intensivos, indicación y selección de tratamiento, seguimiento y tratamiento de la progresión de la enfermedad, predicción del curso clínico, resultados y tratamiento de complicaciones y secuelas.

Abstract Guillain-Barré syndrome (GBS) is a rare, but potentially fatal, immune-mediated disease of the peripheral nerves and nerve roots that is usually triggered by infections. The incidence of GBS can therefore increase during outbreaks of infectious diseases, as was seen during the Zika virus epidemics in 2013 in French Polynesia and in 2015 in Latin America. Diagnosis and management of GBS can be complicated as its clinical presentation and disease course are heterogeneous, and no international clinical guidelines are currently available. To support clinicians, especially in the context of an outbreak, we have developed a globally applicable guideline for the diagnosis and management of GBS. The guideline is based on current literature and expert consensus, and has a ten-step structure to facilitate its use in clinical practice. We first provide an introduction to the diag nostic criteria, clinical variants and differential diagnoses of GBS. The ten steps then cover early recognition and diagnosis of GBS, admission to the intensive care unit, treatment indication and selection, monitoring and treatment of disease progression, prediction of clinical course and outcome, and management of complications and sequelae.

Severe acute myopathy following SARS-CoV-2 infection: a case report and review of recent literature.

BACKGROUND: SARS-CoV2 virus could be potentially myopathic. Serum creatinine phosphokinase (CPK) is frequently found elevated in severe SARS-CoV2 infection, which indicates skeletal muscle damage precipitating limb weakness or even ventilatory failure. CASE PRESENTATION: We addressed such a patient in his forties presented with features of severe SARS-CoV2 pneumonia and high serum CPK. He developed severe sepsis and acute respiratory distress syndrome (ARDS) and received intravenous high dose corticosteroid and tocilizumab to counter SARS-CoV2 associated cytokine surge. After 10 days of mechanical ventilation (MV), weaning was unsuccessful albeit apparently clear lung fields, having additionally severe and symmetric limb muscle weakness. Ancillary investigations in addition with serum CPK, including electromyogram, muscle biopsy, and muscle magnetic resonance imaging (MRI) suggested acute myopathy possibly due to skeletal myositis. CONCLUSION: We wish to stress that myopathogenic medication in SARS-CoV2 pneumonia should be used with caution. Additionally, serum CPK could be a potential marker to predict respiratory failure in SARS-CoV2 pneumonia as skeletal myopathy affecting chest muscles may contribute ventilatory failure on top of oxygenation failure due to SARS-CoV2 pneumonia.

Clinical and serological prognostic factors in childhood Guillain-Barré syndrome: A prospective cohort study in Bangladesh.

Guillain-Barré syndrome (GBS) is the most common cause of acute flaccid paralysis in children. The objective of this study was to investigate the preceding infections, clinical, serological and electrophysiological characteristics and outcome of childhood GBS in Bangladesh. We included 174 patients with GBS aged <18 years from a prospective cohort in Bangladesh between 2010 and 2018. We performed multivariate logistic regression to determine the risk factors for poor outcome. Among 174 children with GBS, 74% (n = 129) were male. Around half of the patients (49%, n = 86) had severe muscle weakness, 65% (n = 113) were bedbound (GBS disability score 4) and 17% (n = 29) patients required mechanical ventilation at admission. Campylobacter jejuni serology and anti-GM1 IgG antibody were positive in 66% and 21% of the patients respectively. One hundred and forty-three (82%) patients did not receive standard treatment and half of them recovered fully or with minor deficits at 6-month. Twenty patients (11%) died throughout the study period. At 3-month of onset of weakness, complete recovery or recovery with minor deficit was significantly higher in demyelinating GBS patients compared to axonal GBS patients (86% vs 51%, P = .001). Cranial nerve palsy (OR = 4.00, 95%CI = 1.55-10.30, P = .004) and severe muscle weakness (OR = 0.16, 95%CI = 0.06-0.45, P = .001) were the important risk factors of poor outcome in children with GBS. Further large-scale studies are required for better understanding of factors associated with mortality and morbidity in childhood GBS.

Changes in motor nerve excitability in acute phase Guillain-Barré syndrome.

BACKGROUND: The most common subtypes of Guillain-Barré syndrome (GBS) are acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN). In the first days after the onset of weakness, standard nerve conduction studies (NCS) may not distinguish GBS subtypes. Reduced nerve excitability may be an early symptom of nerve dysfunction, which can be determined with the compound muscle action potential (CMAP) scan. The aim of this study was to explore whether early changes in motor nerve excitability in GBS patients are related to various subtypes. METHODS: Prospective case-control study in 19 GBS patients from The Netherlands and 22 from Bangladesh. CMAP scans were performed within 2 days of hospital admission and NCS 7-14 days after onset of weakness. CMAP scans were also performed in age- and country-matched controls. RESULTS: CMAP scan patterns of patients who were classified as AMAN were distinctly different compared to the CMAP scan patterns of the patients who were classified as AIDP. The most pronounced differences were found in the stimulus intensity parameters. CONCLUSIONS: CMAP scans made at hospital admission demonstrate several characteristics that can be used as an early indicator of GBS subtype.

Electrophysiology of Guillain-Barré syndrome in Bangladesh: A prospective study of 312 patients.

OBJECTIVE: To describe the electrophysiological features in relation to clinical and serological findings of Guillain-Barré syndrome (GBS) in the national neuroscience hospital in Bangladesh. This is one of the few studies that investigated GBS patients using standardized electrophysiology in low-income countries. METHODS: In a prospective and observational study, we investigated 312 GBS patients by standardized clinical, serological and electrophysiological methods. Unilateral motor and sensory nerve conduction studies (NCS) were performed within two weeks of onset of weakness. Follow up NCS were performed in 189 patients and classified according to eight sets of established GBS criteria. Serology included assessment of anti-GM1 antibodies and anti-campylobacter jejuni lipo-oligosaccharide (LOS) antibodies. RESULTS: Depending on the criteria used, 44-59% patients had axonal GBS with anti-GM1 antibodies being present in 55-58% and 9-42% patients had demyelinating GBS with anti-GM1 antibodies being present in 7-35%. Conduction block (CB) with demyelinative slowing in the same nerve segment was found in 24% (74/312) patients, and CB without demyelinative slowing in the same nerve segment was found in 18% (56/312) patients, of whom anti-GM1 antibodies were found in 27% and 57% patients respectively. Follow-up NCS showed a change in GBS classification in 11-26% of patients, mainly from demyelinating to axonal GBS. CONCLUSIONS: The predominant subtype of GBS in Bangladesh is axonal but demyelinating GBS also occurs with classification being strongly dependent on the applied criteria. SIGNIFICANCE: The present study demonstrates the importance of reaching international agreement on GBS criteria that should be based on the best evidence.

Platinum-induced peripheral neurotoxicity: From pathogenesis to treatment.

Platinum-induced peripheral neurotoxicity (PIPN) is a common side effect of platinum-based chemotherapy that may cause dose reduction and discontinuation, with oxaliplatin being more neurotoxic. PIPN includes acute neurotoxicity restricted to oxaliplatin, and chronic non-length-dependent sensory neuronopathy with positive and negative sensory symptoms and neuropathic pain in both upper and lower limbs. Chronic sensory axonal neuropathy manifesting as stocking-and-glove distribution is also frequent. Worsening of neuropathic symptoms after completing the last chemotherapy course may occur. Motor and autonomic involvement is uncommon. Ototoxicity is frequent in children and more commonly to cisplatin. Platinum-based compounds result in more prolonged neuropathic symptoms in comparison to other chemotherapy agents. Patient reported outcomes questionnaires, clinical evaluation and instrumental tools offer complementary information in PIPN. Electrodiagnostic features include diffusely reduced/abolished sensory action potentials, in keeping with a sensory neuronopathy. PIPN is dependent on cumulative dose but there is a large variability in its occurrence. The search for additional risk factors for PIPN has thus far yielded no consistent findings. There are currently no neuroprotective strategies to reduce the risk of PIPN, and symptomatic treatment is limited to duloxetine that was found effective in a single phase III intervention study. This review critically examines the pathogenesis, incidence, risk factors (both clinical and pharmacogenetic), clinical phenotype and management of PIPN.

Vinca alkaloids, thalidomide and eribulin-induced peripheral neurotoxicity: From pathogenesis to treatment.

Vinca alkaloids, thalidomide, and eribulin are widely used to treat patients with childhood acute lymphoblastic leukemia (ALL), adults affected by multiple myeloma and locally invasive or metastatic breast cancer, respectively. However, soon after their introduction into clinical practice, chemotherapy-induced peripheral neurotoxicity (CIPN) emerged as their main non-hematological and among dose-limiting adverse events. It is generally perceived that vinca alkaloids and the antiangiogenic agent thalidomide are more neurotoxic, compared to eribulin. The exposure to these chemotherapeutic agents is associated with an axonal, length-dependent, sensory polyneuropathy of mild to moderate severity, whereas it is considered that the peripheral nerve damage, unless severe, usually resolves soon after treatment discontinuation. Advanced age, high initial and prolonged dosing, coadministration of other neurotoxic chemotherapeutic agents and pre-existing neuropathy are the common risk factors. Pharmacogenetic biomarkers might be used to define patients at increased susceptibility of CIPN. Currently, there is no established therapy for CIPN prevention or treatment; symptomatic treatment for neuropathic pain and dose reduction or withdrawal in severe cases is considered, at the cost of reduced cancer therapeutic efficacy. This review critically examines the pathogenesis, epidemiology, risk factors (both clinical and pharmacogenetic), clinical phenotype and management of CIPN as a result of exposure to vinca alkaloids, thalidomide and its analogue lenalidomide as also eribulin.

Diagnosis and management of Guillain-Barré syndrome in ten steps.

Guillain-Barré syndrome (GBS) is a rare, but potentially fatal, immune-mediated disease of the peripheral nerves and nerve roots that is usually triggered by infections. The incidence of GBS can therefore increase during outbreaks of infectious diseases, as was seen during the Zika virus epidemics in 2013 in French Polynesia and 2015 in Latin America. Diagnosis and management of GBS can be complicated as its clinical presentation and disease course are heterogeneous, and no international clinical guidelines are currently available. To support clinicians, especially in the context of an outbreak, we have developed a globally applicable guideline for the diagnosis and management of GBS. The guideline is based on current literature and expert consensus, and has a ten-step structure to facilitate its use in clinical practice. We first provide an introduction to the diagnostic criteria, clinical variants and differential diagnoses of GBS. The ten steps then cover early recognition and diagnosis of GBS, admission to the intensive care unit, treatment indication and selection, monitoring and treatment of disease progression, prediction of clinical course and outcome, and management of complications and sequelae.

Neurophysiological, nerve imaging and other techniques to assess chemotherapy-induced peripheral neurotoxicity in the clinical and research settings.

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a common dose-limiting side effect of several anticancer medications. CIPN may involve multiple areas of the peripheral nervous system from the autonomic and dorsal root ganglia (DRG) to the axon and any peripheral nerve fibre type. Large diameter sensory myelinated (Aß) fibres are more frequently involved, but motor, small myelinated (Aδ), unmyelinated (C) or autonomic fibres may also be affected. Here, we review the current evidence on techniques for the CIPN assessment in the clinical and experimental settings. Nerve conduction studies (NCS) may be used at the subclinical and early CIPN stage, to assess the extent of large nerve fibre damage and to monitor long-term outcomes, with the sural or dorsal sural nerve as the most informative. The quantitative sensory neurological examination provides valuable data alongside NCS. Quantitative sensory testing and nerve excitability studies add information regarding pathophysiology. Nerve MRI and ultrasound may provide information on enlarged nerve, increased nerve signal intensity and DRG or spinal cord changes. Skin biopsy, corneal confocal microscopy, laser-evoked potentials, contact heat-related potentials and microneurography may reveal the extent of damage to small unmyelinated nerve fibres that go undetected by NCS. The information on the role of these latter techniques is preliminary. Hence, the use of multimodal testing is recommended as the optimal CIPN assessment strategy, employing objective NCS and other specialised techniques together with subjective patient-reported outcome measures.

Toll-like receptor-4 299Gly allele is associated with Guillain-Barré syndrome in Bangladesh.

OBJECTIVE: TLR4 plays an important role in the pathogenesis of Guillain-Barré syndrome (GBS). The relationships between TLR4 polymorphisms and susceptibility to GBS are poorly understood. We investigated the frequency and assessed the association of two single nucleotide polymorphisms (SNPs) in the extracellular domain of TLR4 (Asp299Gly and Thr399Ile) with disease susceptibility and the clinical features of GBS in a Bangladeshi cohort. METHODS: A total of 290 subjects were included in this study: 141 patients with GBS and 149 unrelated healthy controls. The TLR4 polymorphisms Asp299Gly and Thr399Ile were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. RESULTS: The minor 299Gly allele was significantly associated with GBS susceptibility (P = 0.0137, OR = 1.97, 95% CI = 1.17-3.31), and was present at a significantly higher frequency in patients with the acute motor axonal neuropathy (AMAN) subtype of GBS (P = 0.0120, OR = 2.37, 95% CI = 1.26-4.47) than acute inflammatory demyelinating polyneuropathy (AIDP) subtype (P = 0.961, OR = 1.15, 95% CI = 0.38-3.48); when compared to healthy controls. The genotype frequency of the Asp299Gly polymorphism was not significantly different between patients with GBS and healthy controls. The Asp299-Thr399 haplotype was associated with a significantly lower risk of developing GBS (P = 0.0451, OR = 0.63, 95% CI = 0.40-0.99). No association was observed between the Thr399Ile polymorphism and GBS disease susceptibility. INTERPRETATION: The TLR4 minor 299Gly allele was associated with increased susceptibility to GBS and the axonal GBS subtype in the Bangladeshi population. However, no associations were observed between the genotypes of the Asp299Gly and Thr399Ile SNPs and antecedent C. jejuni infection or disease severity in Bangladeshi patients with GBS.

Proceedings of the Inaugural Strategy Meeting for the Establishment of a Southeast Asia Regional Therapeutic Plasma Exchange Consortium for Neurological Disorders.

In conjunction with the third regional Southeast Asian (SEA) therapeutic plasma exchange (TPE) conference in Kuala Lumpur, Malaysia, 25 clinicians and researchers from SEA and South Asian countries attended the inaugural strategy meeting for the establishment of a regional TPE consortium for neurological disorders. The primary objective was to establish regional collaboration to improve delivery of TPE services in SEA. A pre-meeting survey was conducted to gather insights on disease spectrum, contextual practice challenges, and the need for a regional TPE consensus. Challenges identified include limited healthcare funding in support of diagnostic workup, TPE therapy, as well as development of clinical infrastructure and expertise capacity building. There was favorable interest in developing a working plan contextualized to this region. Strategies to overcome challenges were discussed. This included the need for a comprehensive referral system and network of regional TPE centers suited to local needs, supported by innovative TPE delivery programs.

Risk factors for respiratory failure in Guillain-Barré syndrome in Bangladesh: a prospective study.

Objective: We investigated clinical, biological, and electrophysiological risk factors for mechanical ventilation (MV) and patient outcomes in Bangladesh using one of the largest, prospective Guillain-Barré syndrome (GBS) cohorts in developing world. Methods: A total of 693 GBS patients were included in two GBS studies conducted between 2006 and 2016 in Dhaka, Bangladesh. Associations between baseline characteristics and MV were tested using Fisher's exact test, χ2 test, or Mann-Whitney U-test, as appropriate. Risk factors for MV were assessed using multivariate logistic regression. Survival analysis was performed using Kaplan-Meier method; comparisons between groups performed using log-rank test. Results: Of 693 patients, 155 (23%) required MV (median age, 26 years; interquartile range [IQR] 17-40). Among the ventilated patients, males were predominant (68%) than females. The most significant risk factor for MV was bulbar involvement (adjusted odds ratio [AOR]:19.07; 95% CI = 89.00-192.57, P = 0.012). Other independently associated factors included dysautonomia (AOR:4.88; 95% CI = 1.49-15.98, P = 0.009) and severe muscle weakness at study entry (AOR:6.12; 95% CI = 0.64-58.57, P = 0.048). At 6 months after disease onset, 20% of ventilated and 52% of non-ventilated patients (P < 0.001) had recovered completely or with minor symptoms. Mortality rate was significantly higher among ventilated patients than non-ventilated patients (41% vs. 7%, P < 0.001). Interpretation: Bulbar involvement, dysautonomia and severe muscle weakness were identified as the most important risk factors for MV among GBS patients from Bangladesh. The findings may help to develop predictive models for MV in GBS in developing countries to identify impending respiratory failure and proper clinical management of GBS patients.

Regional variation of Guillain-Barré syndrome.

Guillain-Barré syndrome is a heterogeneous disorder regarding the clinical presentation, electrophysiological subtype and outcome. Previous single country reports indicate that Guillain-Barré syndrome may differ among regions, but no systematic comparative studies have been conducted. Comparative studies are required to identify factors determining disease susceptibility, variation and prognosis, and to improve diagnostic criteria. The International Guillain-Barré Syndrome Outcome Study is a prospective, observational cohort study including all patients within the diagnostic spectrum, aiming to describe the heterogeneity of Guillain-Barré syndrome worldwide. The current study was based on the first 1000 inclusions with a follow-up of at least 1 year and confirmed the variation in clinical presentation, course and outcome between patients. The full clinical spectrum of Guillain-Barré syndrome was observed in patients from all countries participating in the International Guillain-Barré Syndrome Outcome Study, but the frequency of variants differed between regions. We compared three regions based on geography, income and previous reports of Guillain-Barré syndrome subtypes: 'Europe/Americas', 'Asia' (without Bangladesh), and 'Bangladesh'. We excluded 75 (8%) patients because of alternative diagnoses, protocol violations, or missing data. The predominant clinical variant was sensorimotor in Europe/Americas (n = 387/562, 69%) and Asia (n = 27/63, 43%), and pure motor in Bangladesh (n = 74/107, 69%). Miller Fisher syndrome and Miller Fisher-Guillain-Barré overlap syndrome were more common in Asia (n = 14/63, 22%) than in the other two regions (Europe/Americas: n = 64/562, 11%; Bangladesh: n = 1/107, 1%) (P < 0.001). The predominant electrophysiological subtype was demyelinating in all regions (Europe/Americas: n = 312/573, 55%; Asia: n = 29/65, 45%; Bangladesh: n = 38/94, 40%). The axonal subtype occurred more often in Bangladesh (n = 34/94, 36%) than in Europe/Americas (n = 33/573, 6%) and other Asian countries (n = 4/65, 6%) (P < 0.001). In all regions, patients with the axonal subtype were younger, had fewer sensory deficits, and showed a trend towards poorer recovery compared to patients with the demyelinating subtype. The proportion of patients able to walk unaided after 1 year varied between Asia (n = 31/34, 91%), Europe/Americas (n = 334/404, 83%) and Bangladesh (n = 67/97, 69%) (P = 0.003). A similar variation was seen for mortality, being higher in Bangladesh (n = 19/114, 17%) than in Europe/Americas (n = 23/486, 5%) and Asia (n = 1/45, 2%) (P < 0.001). This study showed that factors related to geography have a major influence on clinical phenotype, disease severity, electrophysiological subtype, and outcome of Guillain-Barré syndrome.