Efficient design and analysis of randomized controlled trials in rare neurological diseases: An example in Guillain-Barre syndrome

Background Randomized controlled trials (RCTs) pose specific challenges in rare and heterogeneous neurological diseases due to the small numbers of patients and heterogeneity in disease course. Two analytical approaches have been proposed to optimally handle these issues in RCTs: covariate adjustment and ord

Tracheostomy or Not: Prediction of Prolonged Mechanical Ventilation in Guillain–Barré Syndrome

Background: Respiratory insufficiency occurs in 20 % of Guillain–Barré syndrome (GBS) patients, and the duration of mechanical ventilation (MV) ranges widely. We identified predictors of prolonged MV to guide clinical decision-making on tracheostomy. Methods: We analyzed prospectively collected data from 552 patients with GBS in the context of two clinical trials and three cohort studies in The Netherlands. Potential predictors for prolonged MV, defined as duration of ≥14 days, were considered using crosstabs. Selected predictors were analyzed using Cox regression analysis. Results: On a total of 150 (27 %) patients requiring MV, 106 (71 %) patients needed prolonged MV. The median duration of MV was 28 days (Interquartile Range [IQR] 12–60 days). The strongest observed predictors of prolonged MV were muscle weakness and axonal degeneration or unexcitable nerves on nerve conduction studies. Patients who are unable to lift the arms from the bed (bilateral Medical Research Council [MRC] of deltoid muscles of 0–2) at 1 week after intubation have an 87 % chance to require prolonged MV versus 69 % in patients who are able to lift the arms from the bed (bilateral MRC of deltoid muscles of 3–10). Patients in this last group who had axonal degeneration or unexcitable nerves on nerve conduction studies also have a 90 % chance to require prolonged MV. Conclusions: Ventilated GBS patients who are unable to lift the arms from the bed and patients who have axonal degeneration or unexcitable nerves at 1 week are at high risk of prolonged MV, and tracheostomy should be considered in these patients

IVIg-induced plasmablasts in patients with Guillain-Barré syndrome

Objective: The Guillain–Barré syndrome (GBS) is an acute, immune-mediated disease of peripheral nerves. Plasmablasts and plasma cells play a central role in GBS by producing neurotoxic antibodies. The standard treatment for GBS is high-dose intravenous immunoglobulins (IVIg), however the working mechanism is unknown and the response to treatment is highly variable. We aimed to determine whether IVIg changes the frequency of B-cell subsets in patients with GBS. Methods: Peripheral blood mononuclear cells were isolated from 67 patients with GBS before and/or 1, 2, 4, and 12 weeks after treatment with high-dose IVIg. B-cell subset frequencies were determined by flow cytometry and related to serum immunoglobulin levels. Immunoglobulin transcripts before and after IVIg treatment were examined by next-generation sequencing. Antiglycolipid antibodies were determined by ELISA. Results: Patients treated with IVIg demonstrated a strong increase in plasmablasts, which peaked 1 week after treatment. Flow cytometry identified a relative increase in IgG2 plasmablasts posttreatment. Within IGG sequences, dominant clones were identified which were also IGG2 and had different immunoglobulin sequences compared to pretreatment samples. High plasmablast frequencies after treatment correlated with an increase in serum IgG and IgM, suggesting endogenous production. Patients with a high number of plasmablasts started to improve earlier (P = 0.015) and were treated with a higher dose of IVIg. Interpretation: High-dose IVIg treatment alters the distribution of B-cell subsets in the peripheral blood of GBS patients, suggesting de novo (oligo-)clonal B-cell activation. Very high numbers of plasmablasts after IVIg therapy may be a potential biomarker for fast clinical recovery

IVIG Treatment and Prognosis in Guillain–Barré Syndrome

Introduction Guillain-Barré syndrome (GBS) is an acute, immune-mediated polyneuropathy that often leads to severe weakness. Intravenous immunoglobulin (IVIG) is a proven effective treatment for GBS (class 1 evidence). However, about 25% of patients need artificial ventilation and 20% are still unable to walk unaided after 6 months. Important clinical factors associated with poor outcome are age, presence of preceding diarrhea and the severity of disability in the early course of disease. These clinical factors were combined in a clinical prognostic scoring scale, the Erasmus GBS Outcome Scale (EGOS). Materials and Methods GBS patients being unable to walk unaided are currently treated with a standard single IVIg dose (0.4 g/kg bodyweight for 5 days). A recent retrospective study in 174 GBS patients enrolled in one of our randomized controlled clinical trials showed that patients with a minor increase of serum IgG level after standard single IVIg dose recovered significantly slower. Additionally, fewer patients reached the ability to walk unaided at six months after correction for the known clinical prognostic factors (multivariate analysis; P<0.022). Discussion It is yet unknown why some GBS patients only have a minor increase after standard IVIg treatment. By using the EGOS it is possible to select GBS patients with a poor prognosis. These patients potentially may benefit from a second IVIg dose. Conclusion A standard dose of IVIG is not sufficiently effective in many GBS patients. Whether these patients might benefit from a second IVIg dose needs further investigation

Guillain-Barre syndrome after SARS-CoV-2 infection in an international prospective cohort study

In the wake of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, an increasing number of patients with neurological disorders, including Guillain-Barre syndrome (GBS), have been reported following this infection. It remains unclear, however, if these cases are coincidental or not, as most publications were case reports or small regional retrospective cohort studies. The International GBS Outcome Study is an ongoing prospective observational cohort study enrolling patients with GBS within 2 weeks from onset of weakness. Data from patients included in this study, between 30 January 2020 and 30 May 2020, were used to investigate clinical and laboratory signs of a preceding or concurrent SARS-CoV-2 infection and to describe the associated clinical phenotype and disease course. Patients were classified according to the SARS-CoV-2 case definitions of the European Centre for Disease Prevention and Control and laboratory recommendations of the World Health Organization. Forty-nine patients with GBS were included, of whom eight (16%) had a confirmed and three (6%) a probable SARS-CoV-2 infection. Nine of these 11 patients had no serological evidence of other recent preceding infections associated with GBS, whereas two had serological evidence of a recent Campylobacter jejuni infection. Patients with a confirmed or probable SARS-CoV-2 infection frequently had a sensorimotor variant 8/11 (73%) and facial palsy 7/11 (64%). The eight patients who underwent electrophysiological examination all had a demyelinating subtype, which was more prevalent than the other patients included in the same time window [14/30 (47%), P = 0.012] as well as historical region and age-matched control subjects included in the International GBS Outcome Study before the pandemic [23/44 (52%), P = 0.016]. The median time from the onset of infection to neurological symptoms was 16 days (interquartile range 12-22). Patients with SARS-CoV-2 infection shared uniform neurological features, similar to those previously described in other post-viral GBS patients. The frequency (22%) of a preceding SARS-CoV-2 infection in our study population was higher than estimates of the contemporaneous background prevalence of SARS-CoV-2, which may be a result of recruitment bias during the pandemic, but could also indicate that GBS may rarely follow a recent SARS-CoV-2 infection. Consistent with previous studies, we found no increase in patient recruitment during the pandemic for our ongoing International GBS Outcome Study compared to previous years, making a strong relationship of GBS with SARS-CoV-2 unlikely. A case-control study is required to determine if there is a causative link or not

Second intravenous immunoglobulin dose in patients with Guillain-Barre syndrome with poor prognosis (SID-GBS):a double-blind, randomised, placebo-controlled trial

Background Treatment with one standard dose (2 g/kg) of intravenous immunoglobulin is insufficient in a proportion of patients with severe Guillain-Barre syndrome. Worldwide, around 25% of patients severely affected with the syndrome are given a second intravenous immunoglobulin dose (SID), although it has not been proven effective. We aimed to investigate whether a SID is effective in patients with Guillain-Barre syndrome with a predicted poor outcome. Methods In this randomised, double-blind, placebo-controlled trial (SID-GBS), we included patients (>= 12 years) with Guillain-Barre syndrome admitted to one of 59 participating hospitals in the Netherlands. Patients were included on the first day of standard intravenous immunoglobulin treatment (2 g/kg over 5 days). Only patients with a poor prognosis (score of >= 6) according to the modified Erasmus Guillain-Barre syndrome Outcome Score were randomly assigned, via block randomisation stratified by centre, to SID (2 g/kg over 5 days) or to placebo, 7-9 days after inclusion. Patients, outcome adjudicators, monitors, and the steering committee were masked to treatment allocation. The primary outcome measure was the Guillain-Barre syndrome disability score 4 weeks after inclusion. All patients in whom allocated trial medication was started were included in the modified intention-to-treat analysis. Findings Between Feb 16, 2010, and June 5, 2018, 327 of 339 patients assessed for eligibility were included. 112 had a poor prognosis. Of those, 93 patients with a poor prognosis were included in the modified intention-to-treat analysis: 49 (53%) received SID and 44 (47%) received placebo. The adjusted common odds ratio for improvement on the Guillain-Barre syndrome disability score at 4 weeks was 1.4 (95% CI 0.6-3.3; p=0.45). Patients given SID had more serious adverse events (35% vs 16% in the first 30 days), including thromboembolic events, than those in the placebo group. Four patients died in the intervention group (13-24 weeks after randomisation). Interpretation Our study does not provide evidence that patients with Guillain-Barre syndrome with a poor prognosis benefit from a second intravenous immunoglobulin course; moreover, it entails a risk of serious adverse events. Therefore, a second intravenous immunoglobulin course should not be considered for treatment of Guillain-Barre syndrome because of a poor prognosis. The results indicate the need for treatment trials with other immune modulators in patients severely affected by Guillain-Barre syndrome. Funding Prinses Beatrix Spierfonds and Sanquin Plasma Products. Copyright (C) 2021 Elsevier Ltd. All rights reserved

Emerging drugs for Guillain-Barre syndrome

Introduction: Intravenous immunoglobulin (IVIg) and plasma exchange are proven effective treatments for Guillain-Barre syndrome (GBS). However, this treatment is insufficient for many patients as 1 - 5% die, 25% need artificial respiration, 20% are still unable to walk unaided after 6 months and 85% have residual symptoms, such as fatigue and pain. Areas covered: Strategies to design and conduct trials with new compounds and individualized regimens of IVIg are discussed. The development of specific immunomodulators is set against a background of recent insights in the pathophysiological mechanisms of GBS. Patients with poor prognosis can be identified in the early phase of disease using predictors such as high age, severe disability, preceding diarrhea and possibly low increase in serum IgG after standard IVIg treatment. An ongoing trial with a second IVIg dose in this group and the preclinical development of potential new treatments and their mode of action are discussed. Expert opinion: GBS is a heterogeneous disease with considerable short-and long-term disability for which more effective and individualized treatments are required. Under investigation are new treatment strategies with adapted IVIg dosages based on prognostic factors and more specific immunomodulation, including complement inhibitors

Historical sources of basilar artery occlusion

Posterior circulation stroke, which includes basilar artery occlusion (BAO), accounts for approximately 20% of all ischemic strokes. Much is unclear concerning the early historical descriptions of basilar artery occlusion, and some modern authors cite the historical sources incorrectly and incompletely. The case described by the Scottish physician John Abercrombie in 1828 is probably the first description of this form of stroke. The progressive bulbar signs that Abercrombie described in his case were striking, i.e., dysphagia and speech difficulties. Many authors in the 19th century described a waxing and waning clinical course for several days before profound coma and death. They also noticed signs and symptoms such as hemiplegia without loss of sensitivity and bulbar symptoms such as swallowing and speech impairment, vertigo, and altered consciousness. After Virchow's epoch-making work on embolism and thrombosis, all authors correctly described BAO as resulting from emboli and thrombosis based on arteriosclerosis instead of ossification of the arterial walls or inflammation. Around 1880, the clinical symptoms of BAO were obviously well-known to the experienced clinician. In this article we offer a chronological description of historical sources. Neurology (R) 2011;76:1520-152