Electrophysiological classification of Guillain-Barré syndrome: clinical associations and outcome. Plasma Exchange/Sandoglobulin Guillain-Barré Syndrome Trial Group

Relative frequencies and clinical features of Guillain-Barré Syndrome before and during the COVID-19 pandemic in North China

OBJECTIVE

Most studies investigated the relationship between COVID-19 and Guillain-Barré syndrome (GBS) by comparing the incidence of GBS before and during the pandemic of COVID-19. However, the findings were inconsistent, probably owing to varying degrees of the lockdown policy. The quarantine requirements and travel restrictions in China were lifted around December 7, 2022. This study aimed to explore whether the relative frequency of GBS increased during the major outbreak in the absence of COVID-19-mandated social restrictions in China.

METHODS

GBS patients admitted to the First Hospital, Shanxi Medical University, from December 7, 2022 to February 20, 2023, and from June, 2017 to August, 2019 were included. The relative frequencies of GBS in hospitalized patients during different periods were compared. The patients with and without SARS-CoV-2 infection within six weeks prior to GBS onset formed the COVID-GBS group and non-COVID-GBS group, respectively.

RESULTS

The relative frequency of GBS among hospitalized patients during the major outbreak of COVID-19 (13/14,408) was significantly higher than that before the COVID-19 epidemic (29/160,669, P < 0.001). More COVID-GBS patients (11/13) presented AIDP subtype than non-COVID-GBS cases (10/27, P = 0.003). The mean interval between onset of infective symptoms and GBS was longer in COVID-GBS (21.54 ± 11.56 days) than in non-COVID-GBS (5.76 ± 3.18 days, P < 0.001).

CONCLUSIONS

COVID-19 significantly increased the incidence of GBS. Most COVID-GBS patients fell into the category of AIDP, responded well to IVIg, and had a favorable prognosis.

Clinical predictors for mechanical ventilation assistance in Guillain-Barré syndrome

Background

Guillain-Barré syndrome (GBS) frequently leads to respiratory failure and autonomic dysfunction, resulting in approximately one-third of patients requiring mechanical ventilation.

Objective

This study aimed to identify clinical predictors for mechanical ventilation in patients with GBS.

Methods

This research was conducted from 2010 to 2021 using registries from a tertiary hospital in an upper middle-income Latin American country. Participants were categorized into two groups based on their ventilation status. Demographic data were collected, and independent predictors of the need for mechanical ventilation were determined through multivariate logistic regression analysis.

Results

Dysautonomic events occurred in 36% of the patients, with 17% requiring mechanical ventilation; the average duration of intubation was 1.16 ± 3.18 days. The multivariate analysis indicated that bulbar dysfunction significantly increased the likelihood of requiring mechanical ventilation by 19-fold (OR 18.67, 95% CI 5.85-59.42), followed by ophthalmoplegia, which increased the likelihood by sixfold (OR 5.68, 95% CI 1.28-25.19).

Conclusion

Bulbar dysfunction, dysautonomia, and lower Medical Research Council (MRC) scores were significant predictors of the need for mechanical ventilation in hospitalized GBS patients. These findings support the need for close monitoring and early admission to the intensive care unit (ICU) admission for at-risk patients.

The sural-sparing pattern in clinical variants and electrophysiological subtypes of Guillain-Barré syndrome

BACKGROUND

 Guillain-Barré syndrome (GBS) is the most common cause of acute flaccid paralysis worldwide and can be classified into electrophysiological subtypes and clinical variants.

OBJECTIVE

 This study aimed to compare the frequency of the sural-sparing pattern (SSP) in subtypes and variants of GBS.

METHODS

 This retrospective cohort study analyzed clinical and electrophysiological data of 171 patients with GBS hospitalized in public and private hospitals of Natal, Rio Grande do Norte, Brazil, between 1994 and 2018; all cases were followed up by the same neurologist in a reference neurology center. Patients were classified according to electrophysiological subtypes and clinical variants, and the SSP frequency was compared in both categories. The exact Fisher test and Bonferroni correction were used for statistical analysis.

RESULTS

 The SSP was present in 53% (57 of 107) of the patients with acute inflammatory demyelinating polyradiculoneuropathy (AIDP), 8% (4 of 48) of the patients with axonal subtypes, and 31% (5 of 16) of the equivocal cases. The SSP frequency in the AIDP was significantly higher than in the axonal subtypes (p < 0.0001); the value was kept high after serial electrophysiological examinations. Only the paraparetic subtype did not present SSP.

CONCLUSION

 The SSP may be present in AIDP and axonal subtypes, including acute motor axonal neuropathy, but it is significantly more present in AIDP. Moreover, the clinical variants reflect a specific pathological process and are correlated to its typical electrophysiological subtype, affecting the SSP frequency.

Dynamics and prognostic value of serum neurofilament light chain in Guillain-Barré syndrome

BACKGROUND

Neurofilament light chain (NfL) is a biomarker for axonal damage in several neurological disorders. We studied the longitudinal changes in serum NfL in patients with Guillain-Barré syndrome (GBS) in relation to disease severity, electrophysiological subtype, treatment response, and prognosis.

METHODS

We included patients with GBS who participated in a double-blind, randomised, placebo-controlled trial that evaluated the effects of a second course of intravenous immunoglobulin (IVIg) on clinical outcomes. Serum NfL levels were measured before initiation of treatment and at one, two, four, and twelve weeks using a Simoa HD-X Analyzer. Serum NfL dynamics were analysed using linear mixed-effects models. Logistic regression was employed to determine the associations of serum NfL with clinical outcome and the prognostic value of serum NfL after correcting for known prognostic markers included in the modified Erasmus GBS Outcome Score (mEGOS).

FINDINGS

NfL levels were tested in serum from 281 patients. Serum NfL dynamics were associated with disease severity and electrophysiological subtype. Strong associations were found between high levels of serum NfL at two weeks and inability to walk unaided at four weeks (OR = 1.74, 95% CI = 1.27-2.45), and high serum NfL levels at four weeks and inability to walk unaided at 26 weeks (OR = 2.79, 95% CI = 1.72-4.90). Baseline serum NfL had the most significant prognostic value for ability to walk, independent of predictors included in the mEGOS. The time to regain ability to walk unaided was significantly longer for patients with highest serum NfL levels at baseline (p = 0.0048) and week 2 (p < 0.0001). No differences in serum NfL were observed between patients that received a second IVIg course vs. IVIg and placebo.

INTERPRETATION

Serum NfL levels are associated with disease severity, axonal involvement, and poor outcome in GBS. Serum NfL potentially represents a biomarker to monitor neuronal damage in GBS and an intermediate endpoint to evaluate the effects of treatment.

FUNDING

Prinses Beatrix Spierfonds W.OR19-24.

Electrodiagnostic methods to verify Guillain-Barré syndrome subtypes in Istanbul: A prospective multicenter study

BACKGROUND AND AIMS

This study aimed to identify the clinical characteristics and electrodiagnostic subtypes of Guillain-Barré syndrome (GBS) in Istanbul.

METHODS

Patients with GBS were prospectively recruited between April 2019 and March 2022 and two electrodiagnostic examinations were performed on each patient. The criteria of Ho et al., Hadden et al., Rajabally et al., and Uncini et al. were compared for the differentiation of demyelinating and axonal subtypes, and their relations with anti-ganglioside antibodies were analyzed.

RESULTS

One hundred seventy-seven patients were included, 69 before the coronavirus disease 2019 pandemic (April 2019-February 2020) and 108 during the pandemic (March 2020-March 2022), without substantial changes in monthly frequencies. As compared with the criteria of Uncini et al., demyelinating GBS subtype diagnosis was more frequent according to the Ho et al. and Hadden et al. criteria (95/162, 58.6% vs. 110/174, 63.2% and 121/174, 69.5%, respectively), and less frequent according to Rajabally et al.'s criteria (76/174, 43.7%). Fourteen patients' diagnoses made using Rajabally et al.'s criteria were shifted to the other subtype with the second electrodiagnostic examination. Of the 106 analyzed patients, 22 had immunoglobulin G anti-ganglioside antibodies (14 with the axonal subtype). They had less frequent sensory symptoms (54.5% vs. 83.1%, p = 0.009), a more frequent history of previous gastroenteritis (54.5% vs. 22.9%, p = 0.007), and a more severe disease as compared with those without antibodies.

INTERPRETATION

Serial electrodiagnostic examinations are more helpful for accurate subtype diagnosis of GBS because of the dynamic pathophysiology of the disease. We observed no significant increase in GBS frequency during the pandemic in this metropolis.

COVID-19-associated serum and cerebrospinal fluid cytokines in post- versus para-infectious SARS-CoV-2-related Guillain-Barré syndrome

INTRODUCTION

Guillain-Barré syndrome associated with Coronavirus-2-related severe acute respiratory syndrome (COV-GBS) occurs as para- or post-infectious forms, depending on the timing of disease onset. In these two forms, we aimed to compare the cerebrospinal fluid (CSF) and serum proinflammatory cytokine profiles to evaluate differences that could possibly have co-pathogenic relevance.

MATERIALS AND METHODS

We studied a retrospective cohort of 26 patients with either post-COV-GBS (n = 15), with disease onset occurring > 7 days after SARS-CoV-2 infection, or para-COV-GBS (n = 11), with disease onset 7 days or less. TNF-α, IL-6, and IL-8 were measured in the serum with SimplePlex™ Ella™ immunoassay. In addition to the para-/post-COV-GBS patients, serum levels of these cytokines were determined in those with non-COVID-associated-GBS (NC-GBS; n = 43), paucisymptomatic SARS-CoV-2 infection without GBS (COVID, n = 20), and in healthy volunteers (HV; n = 12). CSF cytokine levels were measured in patients with para-/post-COV-GBS, in those with NC-GBS (n = 29), or with Alzheimer's disease (AD; n = 24).

RESULTS

Serum/CSF cytokine levels did not differ in para- vs post-COV-GBS. We found that SARS-CoV-2 infection raises the serum levels of TNF-α, IL-6, and IL-8, as well as an increase of IL-6 (in serum and CSF) and IL-8 (in CSF) in either NC-GBS or COV-GBS than controls. CSF and serum cytokine levels resulted independent one with another.

CONCLUSIONS

The change of cytokines linked to SARS-CoV-2 in COV-GBS appears to be driven by viral infection, although it has unique characteristics in GBS as such and does not account for cases with para- or post-infectious onset.

Serial Nerve Conduction Studies in Guillain-Barré Syndrome: Its Usefulness and Precise Timing

PURPOSE

Nerve conduction study (NCS) is essential for subclassifying Guillain-Barré syndrome (GBS). It is well known that the GBS subclassification can change through serial NCSs. However, the usefulness of serial NCSs is debatable, especially in patients with early stage GBS.

METHODS

Follow-up NCS data within 3 weeks (early followed NCS, EFN) and within 3 to 10 weeks (late-followed NCS, LFN) were collected from 60 patients with GBS who underwent their first NCS (FN) within 10 days after symptom onset. Each NCS was classified into five subtypes (normal, demyelinating, axonal, inexcitable, and equivocal), according to Hadden's and Rajabally's criteria. We analyzed the frequency of significant changes in classification (SCCs) comprising electrodiagnostic aggravation and subtype shifts between demyelinating and axonal types according to follow-up timing.

RESULTS

Between FN and EFN, 33.3% of patients with Hadden's criteria and 18.3% with Rajabally's criteria showed SCCs. Between FN and LFN, 23.3% of patients with Hadden's criteria and 21.7% with Rajabally's criteria showed SCCs, of which 71.4% (Hadden's criteria) and 46.2% (Rajabally's criteria) already showed SCCs from the EFN. The conditions of delayed SCCs between EFN and LFN were very early FN, mild symptoms at the FN, or persistent electrophysiological deterioration 3 weeks after symptom onset.

CONCLUSIONS

A substantial proportion of patients with GBS showed significant changes in neurophysiological classification at the early stage. Serial NCS may be helpful for precise neurophysiological classification. This study suggests that follow-up NCSs should be performed within 3 weeks of symptom onset in patients with GBS in whom FN was performed within 10 days of symptom onset.

Understanding Neuropathy Features in the Context of Nitrous Oxide Abuse: A Combined Electrophysiological and Metabolic Approach

BACKGROUND

The incidence of neurological complications associated with nitrous oxide (N2O) abuse, including N2O-induced myelopathy and neuropathy, has risen in the past decade. N2O-induced neuropathy often presents as a subacute axonal pathology; however, demyelinating patterns mimicking Guillain-Barré syndrome have also been observed. This study explores the metabolic pathophysiology of N2O-induced neuropathy, focusing on the alteration in metabolism to provide a deeper understanding of the biochemical pathways influencing the diverse electrophysiological patterns observed.

METHODS

We conducted a combined metabolic and electrophysiological exploration of 35 patients who underwent electromyographic exams at our referral center over a three-year period for sensorimotor symptoms linked to recreational N2O use. We collected demographic, clinical, radiological, electrophysiological, and biological data. Patients were categorized into axonal or demyelinating groups based on their electrophysiological patterns, and metabolic parameters were compared.

RESULTS

Our cohort predominantly exhibited a length-dependent sensorimotor axonal symmetrical neuropathy affecting the lower limbs. Among the patients, 40% met the demyelinating criteria, with four patients exhibiting conduction blocks. The demyelinating group had a significantly higher peripheral neuropathy disability (PND) score at diagnosis. Elevated homocysteine and methylmalonic acid (MMA) levels were noted in all patients, but these were lower in the demyelinating group.

CONCLUSIONS

This study highlights the diverse electrophysiological manifestations of N2O-induced neuropathy and underscores the potential role of metabolic parameters as biomarkers to understand its pathophysiology. Lower hyperhomocysteinemia and MMA levels were observed in demyelinating patterns. In this study, we did not observe further improvement, but it is well-known that demyelinating features have a better prognosis related to the further remyelination. These findings contribute to a better understanding of N2O-related neuropathic damage and could guide future therapeutic interventions based on biochemical-neurophysiological stratifications.

Predictors of respiratory failure in Guillain-Barré syndrome: a 22 year cohort study from a single Italian centre

BACKGROUND AND PURPOSE

The study aimed to identify predictors of respiratory failure leading to mechanical ventilation (MV) and tracheostomy in Guillain-Barré syndrome (GBS).

METHODS

Two hundred and thirty adult cases admitted to the Neurology Unit of Modena, Italy, between January 2000 and December 2021 were studied. A cut-off of MV starting within 8 weeks from onset of weakness was used. Univariable, multivariable logistic and Cox regression analyses were used to determine which pre-specified clinical and diagnostic characteristics were capable of predicting MV and tracheostomy, due to weaning failure. The model was internally validated within the full cohort. The Erasmus GBS Respiratory Insufficiency Score was retrospectively applied.

RESULTS

One hundred and seventy-six cases (76.5%) were classified as classical sensorimotor GBS and 54 (23.4%) as variants. Thirty-two patients (13.9%) needed MV: 84.3% required respiratory support within 7 days. Independent predictors of respiratory failure and MV were older age, facial, bulbar, neck flexor weakness, dysautonomia, axonal electrophysiological subtype, cardiovascular comorbidities and higher disability score at entry. There was no association with abnormal spinal fluid parameters nor with positive serology for recent infections. Twenty-two patients (68.7%) were ventilated for more than 7 days; 4.7% died within 8 weeks. The patients who required MV were treated more often with plasma exchange. Independent predictors of tracheostomy due to weaning trial failure were facial, bulbar, neck flexor weakness, autonomic dysfunction, associated cardiovascular morbidities and axonal electrophysiological subtype on nerve conduction study.

CONCLUSIONS

Our study indicates distinct predictors of MV and tracheostomy in GBS patients.

Risk factors for respiratory failure among hospitalized patients with Guillain-Barré syndrome

BACKGROUND

Guillain-Barré syndrome (GBS) is an acute inflammatory polyneuropathy that can lead to respiratory failure. In this study, we evaluate early clinical risk factors for respiratory failure at the time of hospital admission.

METHODS

We studied a retrospective cohort of patients with GBS admitted to a tertiary care center. The potential risk factors studied were sociodemographic characteristics, GBS symptoms, overall and cervical muscle weakness (Medical Research Council [MRC] scores), electromyography findings, and cerebrospinal fluid analysis findings. Unadjusted odds ratios (OR) were calculated and exact logistic regression analysis (adjusted OR) performed to assess the association between baseline risk factors and respiratory failure.

RESULTS

Overall, 13 of 113 (12%) patients included in the study developed respiratory failure. Unadjusted analyses showed that involvement of any cranial nerve (OR: 14.7; 95% CI, 1.8-117.1), facial palsy (OR: 17.3; 95% CI, 2.2-138.0), and bulbar weakness (OR: 10.7; 95% CI, 2.3-50.0) were associated with increased risk of respiratory failure. Lower MRC sum scores (for scores <30, OR: 14.0; 95% CI, 1.54-127.2) and neck MRC scores (for scores ≤3, OR: 21.0; 95% CI, 3.5-125.2) were associated with higher likelihood of respiratory failure. Adjusted analyses showed that presence of bulbar weakness (OR: 7.6; 95% CI, 1.3-43.0) and low neck MRC scores (scores ≤3, OR: 9.2; 95% CI, 3.5-125.2, vs scores >3) were independently associated with respiratory failure.

CONCLUSIONS

Bulbar and neck muscle weakness at admission are clinical predictors of increased risk of respiratory failure in patients with GBS. These findings could guide the adequate management of high-risk patients.

Neuropathies related to hepatitis E virus infection: A prospective, matched case-control study

BACKGROUND

Acute hepatitis E virus (HEV) infection has recently emerged as a potential trigger for acute dysimmune neuropathies, but prospective controlled studies are lacking.

AIMS

To compare the frequency of concomitant acute HEV infection in patients with neuralgic amyotrophy (NA), Guillain-Barré syndrome (GBS), and Bell's palsy with a matched control population.

METHODS

Swiss multicenter, prospective, observational, matched case-control study over 3 years (September 2019-October 2022). Neurological cases with NA, GBS, or Bell's palsy were recruited within 1 month of disease onset. Healthy controls were matched for age, sex, geographical location, and timing of blood collection. Diagnostic criteria for acute hepatitis E were reactive serum anti-HEV IgM and IgG assays (ELISA test) and/or HEV RNA detection in serum by real-time polymerase chain reaction (RT-PCR). RT-PCR was performed on sera to confirm IgM positivity.

RESULTS

We included 180 patients (59 GBS, 51 NA, 70 Bell's palsy cases) and corresponding matched controls (blood donors) with median age 51 years for both groups and equal gender distribution. Six IgM+ cases were detected in the NA, two in the GBS, and none in the Bell's palsy group. Two controls were anti-HEV IgM-positive. At disease onset, most cases with acute HEV infection had increased liver enzymes. A moderate association (p = 0.027, Fisher's exact test; Cramér's V = -0.25) was observed only between acute HEV infection and NA.

CONCLUSION

This prospective observational study suggests an association between concomitant acute HEV infection and NA, but not with GBS or Bell's palsy.

A Study of Sensory Nerve Conduction in Pre- and Post-immunoglobulin Treatment of Guillain-Barré Syndrome

BACKGROUND

Guillain-Barré syndrome (GBS) is a condition characterized by acute and progressive weakness that impacts the limbs, facial muscles, and bulbar muscles due to acute polyneuro-radiculopathy. Typically, an infection that results in immune-mediated nerve dysfunction is what starts the disease. Patients often encounter paresthesia or discomfort before progressing to muscle weakness, initially in the lower extremities (which may include some proximal components) and subsequently in the upper extremities. The features of polyneuropathy identified during electrophysiology tests, bolstered by evidence of acquired demyelination in the nerve conduction study (NCS), support the clinical diagnosis of GBS. In peripheral neuropathies, NCS often reveals abnormalities in nerve conduction parameters. A specific pattern observed in the sensory nerve conduction study (SNCS), referred to as "sural sparing," signifies that the sural nerve, located near the calf muscles, remains relatively unaffected compared to other sensory nerves. Very few studies have been conducted to investigate improvements in sensory nerve conduction (SNC) parameters before and after intravenous immunoglobulin (IVIG), offering limited clinical correlation for the recovery and prognosis of the disease. The study aimed to observe the NCS parameters of the sensory nerves in both the upper and lower limbs, before and after the infusion of IVIG.

METHODOLOGY

This study was an observational investigation conducted in the neurophysiology laboratory of the Physiology Department at a rural medical college in central India. Fifty clinically diagnosed cases of GBS aged between 18 and 60 years were referred from the Department of Medicine to the Physiology Department for conducting the NCS. Basic sociodemographic information, along with clinical history, was collected. Subsequently, the RMS EMG EP Mark-II machine was employed to examine the sensory nerve action potentials (SNAPs), such as amplitude (in mV) and conduction velocity (in ms), of the sensory nerves in both the upper and lower limbs before and after IVIG infusion. The IVIG infusion occurs within one week of clinically diagnosing GBS. Following an initial NCS, a second NCS follow-up study was conducted one week after the IVIG infusion to analyze the changing trend in sensory nerves.

RESULTS

Upon analysis, no significant correlation was observed between the pre- and post-IVIG SNAPs of the median and ulnar nerves. However, the sural nerve conduction velocity's p-value of 0.033 demonstrated statistical significance, suggesting that the sural nerve is comparatively spared, confirming sural sparing. However, the SNAP of the sensory nerves in GBS patients showed a significant improvement overall, and only NCS quantified the percentage of improvement.

CONCLUSION

According to the study, the NCS of sensory nerves showed a positive change in the parameters examined before and after the infusion of IVIG. This underscores the timely intervention of GBS with IVIG, and conducting the sensory conduction study diligently will enhance knowledge about the recovery period. Additionally, it supports the treating physician in making informed interventions based on the results post-IVIG infusion. This enhancement in the sensory nerves can only be quantified through NCS.

CSF CXCL13 is elevated in patients with CIDP and may reflect higher disease activity

To evaluate B-cell involvement in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), 11 patients with CIDP, 8 patients with Guillain-Barré syndrome and 13 patients with idiopathic normal pressure hydrocephalus (iNPH) were studied. CSF cytokine and chemokine (IL-10, IL-15, TNF-α, TGF-β1, GM-CSF, BAFF, CXCL10, and CXCL13) levels were measured by ELISA. The CSF CXCL13 level was significantly higher in patients with CIDP than in those with iNPH. The CSF CXCL13 level was significantly higher in CIDP patients with higher annualized relapse rates and higher modified Rankin scale scores. The CSF CXCL13 level is elevated in CIDP, especially in those with higher disease activity.

Current status of Guillain-Barré syndrome (GBS) in China: a 10-year comprehensive overview

Guillain-Barré syndrome (GBS) is an acute inflammatory polyradiculoneuropathy; a disease involving the peripheral nervous system which is the most common cause of acute flaccid paralysis worldwide. So far, it is still lack of a comprehensive overview and understanding of the national epidemiological, clinical characteristics, and the risk factors of GBS in China, as well as differences between China and other countries and regions in these respects. With the global outbreak of the coronavirus disease 2019 (COVID-19), an epidemiological or phenotypic association between severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and GBS has attracted great attention. In this review, we outlined the current clinical data of GBS in China by retrieving literature, extracting and synthesizing the data of GBS in China from 2010 to 2021. Besides, we compared the characteristics of epidemiology, preceding events and clinical profiles of GBS between China and other countries and regions. Furthermore, in addition to conventional intravenous immunoglobulin (IVIG) and plasma exchange (PE) therapy, the potential therapeutic effects with novel medications in GBS, such as complement inhibitors, etc., have become the research focus in treatments. We found that epidemiological and clinical findings of GBS in China are approximately consistent with those in the International GBS Outcome Study (IGOS) cohort. We provided an overall picture of the present clinical status of GBS in China and summarized the global research progress of GBS, aiming to further understand the characteristics of GBS and improve the future work of GBS worldwide, especially in countries with the middle and low incomes.

European Academy of Neurology/Peripheral Nerve Society Guideline on diagnosis and treatment of Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is an acute polyradiculoneuropathy. Symptoms may vary greatly in presentation and severity. Besides weakness and sensory disturbances, patients may have cranial nerve involvement, respiratory insufficiency, autonomic dysfunction and pain. To develop an evidence-based guideline for the diagnosis and treatment of GBS, using Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology a Task Force (TF) of the European Academy of Neurology (EAN) and the Peripheral Nerve Society (PNS) constructed 14 Population/Intervention/Comparison/Outcome questions (PICOs) covering diagnosis, treatment and prognosis of GBS, which guided the literature search. Data were extracted and summarised in GRADE Summaries of Findings (for treatment PICOs) or Evidence Tables (for diagnostic and prognostic PICOs). Statements were prepared according to GRADE Evidence-to-Decision (EtD) frameworks. For the six intervention PICOs, evidence-based recommendations are made. For other PICOs, good practice points (GPPs) are formulated. For diagnosis, the principal GPPs are: GBS is more likely if there is a history of recent diarrhoea or respiratory infection; CSF examination is valuable, particularly when the diagnosis is less certain; electrodiagnostic testing is advised to support the diagnosis; testing for anti-ganglioside antibodies is of limited clinical value in most patients with typical motor-sensory GBS, but anti-GQ1b antibody testing should be considered when Miller Fisher syndrome (MFS) is suspected; nodal-paranodal antibodies should be tested when autoimmune nodopathy is suspected; MRI or ultrasound imaging should be considered in atypical cases; and changing the diagnosis to acute-onset chronic inflammatory demyelinating polyradiculoneuropathy (A-CIDP) should be considered if progression continues after 8 weeks from onset, which occurs in around 5% of patients initially diagnosed with GBS. For treatment, the TF recommends intravenous immunoglobulin (IVIg) 0.4 g/kg for 5 days, in patients within 2 weeks (GPP also within 2-4 weeks) after onset of weakness if unable to walk unaided, or a course of plasma exchange (PE) 12-15 L in four to five exchanges over 1-2 weeks, in patients within 4 weeks after onset of weakness if unable to walk unaided. The TF recommends against a second IVIg course in GBS patients with a poor prognosis; recommends against using oral corticosteroids, and weakly recommends against using IV corticosteroids; does not recommend PE followed immediately by IVIg; weakly recommends gabapentinoids, tricyclic antidepressants or carbamazepine for treatment of pain; does not recommend a specific treatment for fatigue. To estimate the prognosis of individual patients, the TF advises using the modified Erasmus GBS outcome score (mEGOS) to assess outcome, and the modified Erasmus GBS Respiratory Insufficiency Score (mEGRIS) to assess the risk of requiring artificial ventilation. Based on the PICOs, available literature and additional discussions, we provide flow charts to assist making clinical decisions on diagnosis, treatment and the need for intensive care unit admission.

Predicting of Mechanical Ventilation and Outcomes by Using Models and Biomarker in Guillain-Barré Syndrome

BACKGROUND

Guillain-Barré syndrome (GBS) is an acute inflammatory neuropathy. The Erasmus GBS Respiratory Insufficiency Score (EGRIS) and the modified Erasmus GBS Outcome Score (mEGOS) are prognostic models used in the prediction of mechanical ventilation and outcome. Thus far, there are only few biomarkers for the prognosis prediction of GBS patients, and albumin level is one that is promising.

METHODS

Patients diagnosed with GBS from 2013 to 2022 at Renmin Hospital, Wuhan University, China, were included. Patients hospitalized between 2016 and 2022 underwent short- and long-term follow-ups. The correlations between EGRIS/mEGOS and mechanical ventilation and outcome were evaluated. Serum albumin level was examined the day after admission. Furthermore, we also investigated whether the level of serum albumin was useful in predicting disease severity or poor outcome.

RESULTS

In all, 145 patients were enrolled. Nineteen patients (13.1%) who required mechanical ventilation had higher Hughes GBS disability score (HGDS) at admission and discharge (P < 0.05 and P < 0.0001, respectively), shorter time from onset to admission and treatment (P < 0.01 and P < 0.001, respectively) and longer hospital stays (P < 0.001) than patients who did not require mechanical ventilation. High EGRIS scores were linked with the need for mechanical ventilation (r = 0.427, P < 0.001, AUC = 0.623). Seventy-one patients were admitted between 2016 and 2022. Of these, 65 patients had a 4-week follow-up and 61 had a 6-month follow-up. Higher mEGOS scores at admission and 7 days after admission significantly correlated with short- (P < 0.0001 and P < 0.0001) and long-term (P < 0.05 and P < 0.05) outcomes, respectively. No significant difference in outcome was found between different subtypes (4 weeks [P = 0.099] and 6 months [P = 0.172]). Patients with lower albumin level tended to have higher HGDS (at admission P < 0.05, at nadir P < 0.001, and at discharge P < 0.001) and higher properties of the need of mechanical ventilation (P < 0.05) and ICU stay (P < 0.05) than those with normal albumin levels. Those with low albumin levels were also unable to walk independently at 6 months (P < 0.01).

CONCLUSIONS

mEGOS scores predicted the outcomes of GBS patients in China, and EGRIS score predicted the need for mechanical ventilation in these patients. Albumin level at admission correlated well with disease severity and outcomes.

Deltoid muscle strength and autonomic dysfunction as independent risk factors for invasive mechanical ventilation in patients with Guillain-Barré syndrome

BACKGROUND

Almost a third of patients with Guillain-Barré Syndrome (GBS) require mechanical ventilation, increasing mortality by 15-30% and proving poor functional outcomes. The Erasmus GBS Respiratory Insufficiency Score (EGRIS) is the most frequently used scale to assess probability of respiratory insufficiency within the first week of admission. We aim to determine other clinical and electrophysiological prognostic factors for invasive mechanical ventilation (IMV) in patients with GBS.

MATERIAL AND METHODS

A cross-sectional ambispective cohort study was carried out in a referral center in Mexico City, from January 2015 to December 2019. Baseline demographics, MRC score, Hughes scale, EGRIS, dysautonomia and nerve conduction studies were performed on admission in GBS patients that required IMV. A multivariable analysis for IMV and a survival analysis for independent walk in prolonged-IMV (>14 days) were performed.

RESULTS

Forty-nine (32%) out of 153 GBS patients required IMV. Statistically significant prognostic factors in multivariable analysis were deltoid muscle strength ≤2 [OR 7.1 (1.6-31.1)], EGRIS [OR 2.5 (1.3-4.6)] and autonomic dysfunction [OR 6.6 (2.0-22.0)]. Electrodecrement <1 mV in the compound muscle action potential (CMAP) of distal motor median nerve was more prevalent in prolonged-IMV patients (44.8% vs. 21%, p = .049). A significant minor prevalence of prolonged-IMV patients regain independent walk at 6 months using the Kaplan-Meier method (log rank test p < .001).

CONCLUSIONS

We provide new specific clinical (deltoid muscle strength and autonomic dysfunction) and electrophysiological variables to discriminate GBS patients that will require IMV.

European Academy of Neurology/Peripheral Nerve Society Guideline on diagnosis and treatment of Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is an acute polyradiculoneuropathy. Symptoms may vary greatly in presentation and severity. Besides weakness and sensory disturbances, patients may have cranial nerve involvement, respiratory insufficiency, autonomic dysfunction and pain. To develop an evidence-based guideline for the diagnosis and treatment of GBS, using Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology, a Task Force (TF) of the European Academy of Neurology (EAN) and the Peripheral Nerve Society (PNS) constructed 14 Population/Intervention/Comparison/Outcome questions (PICOs) covering diagnosis, treatment and prognosis of GBS, which guided the literature search. Data were extracted and summarised in GRADE Summaries of Findings (for treatment PICOs) or Evidence Tables (for diagnostic and prognostic PICOs). Statements were prepared according to GRADE Evidence-to-Decision (EtD) frameworks. For the six intervention PICOs, evidence-based recommendations are made. For other PICOs, good practice points (GPPs) are formulated. For diagnosis, the principal GPPs are: GBS is more likely if there is a history of recent diarrhoea or respiratory infection; CSF examination is valuable, particularly when the diagnosis is less certain; electrodiagnostic testing is advised to support the diagnosis; testing for anti-ganglioside antibodies is of limited clinical value in most patients with typical motor-sensory GBS, but anti-GQ1b antibody testing should be considered when Miller Fisher syndrome (MFS) is suspected; nodal-paranodal antibodies should be tested when autoimmune nodopathy is suspected; MRI or ultrasound imaging should be considered in atypical cases; and changing the diagnosis to acute-onset chronic inflammatory demyelinating polyradiculoneuropathy (A-CIDP) should be considered if progression continues after 8 weeks from onset, which occurs in around 5% of patients initially diagnosed with GBS. For treatment, the TF recommends intravenous immunoglobulin (IVIg) 0.4 g/kg for 5 days, in patients within 2 weeks (GPP also within 2-4 weeks) after onset of weakness if unable to walk unaided, or a course of plasma exchange (PE) 12-15 L in four to five exchanges over 1-2 weeks, in patients within 4 weeks after onset of weakness if unable to walk unaided. The TF recommends against a second IVIg course in GBS patients with a poor prognosis; recommends against using oral corticosteroids, and weakly recommends against using IV corticosteroids; does not recommend PE followed immediately by IVIg; weakly recommends gabapentinoids, tricyclic antidepressants or carbamazepine for treatment of pain; does not recommend a specific treatment for fatigue. To estimate the prognosis of individual patients, the TF advises using the modified Erasmus GBS outcome score (mEGOS) to assess outcome, and the modified Erasmus GBS Respiratory Insufficiency Score (mEGRIS) to assess the risk of requiring artificial ventilation. Based on the PICOs, available literature and additional discussions, we provide flow charts to assist making clinical decisions on diagnosis, treatment and the need for intensive care unit admission.

Dose-Effect Relationship of Motor Nerve Inexcitability on Outcome in Guillain-Barré Syndrome: A Prospective Cohort Study

Objective

One or more inexcitable motor (IM) nerves are common during electrodiagnostic (EDx) study in Guillain-Barré syndrome (GBS). This study assessed the dose-effect relationship of IM nerves on outcome in patients with acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor and/or sensory axonal neuropathy (AMAN and AMSAN).

Materials and Methods

Eighty-eight GBS patients admitted during May 2018-June 2023 underwent detailed clinical evaluation and EDx study. Admission and follow-up disability were assessed on a 0-10 Clinical Grading Scale (CGS). Outcome was recovery at 6 months, defined as good (CGS <3) and poor (CGS ≥3). Binary multivariate logistic regression with backward elimination was used to calculate independent predictors of outcome.

Results

Proportion of patients with complete recovery decreased significantly with increasing numbers of IM nerves (P < 0.01). Seventy-six patients were followed for 6 months. Among patients with IM nerves (n = 28), complete recovery was similar between AIDP and axonal GBS (70% vs. 50%, respectively; P = 0.40). However, in patients with recordable compound muscle action potentials (CMAPs) in all the motor nerves (n = 26), axonal GBS had significantly poor recovery compared to AIDP (75% vs. 9.1%; P = 0.01). Among patients receiving intravenous immunoglobulin (IVIg; n = 42), poor recovery was seen in 53.6% with IM nerves compared to 35.7% without (P = 0.28), while it was 37.5% versus 5.6% (P = 0.04), respectively, in those who did not receive IVIg (n = 34). However, only admission disability (odds ratio [OR] 0.88, 95% confidence interval [CI] 0.81-0.97; P = 0.007) was found to be an independent predictor of outcome.

Conclusion

Although increasing numbers of IM nerves were associated with poor outcome on univariate analysis, they did not predict 6 months' outcome independently. Outcome did not differ between axonal GBS and AIDP among those with IM nerves. IVIg improved outcome in patients with IM nerves.

Characteristics of Patients Diagnosed With Guillain-Barré Syndrome at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, From 2000 to 2018

BACKGROUND

Guillain-Barré syndrome (GBS) is the leading cause of non-polio acute flaccid paralysis worldwide, emphasizing the importance of epidemiological studies on this condition. Therefore, well-designed epidemiological studies in different populations can provide a better understanding of the characteristics of patients with GBS and the nature of the disease. To our knowledge, no previous study has attempted to describe the characteristics of patients with GBS in Kingdom of Saudi Arabia (KSA) based on disease subtypes and clinical features in both adult and pediatric patients. This study aimed to assess the frequencies of GBS subtypes and their relationships with patient characteristics and clinical data in a tertiary hospital in Jeddah, KSA.

METHODS

This was a retrospective review of patients diagnosed with GBS between January 2000 and January 2018 at King Abdulaziz University Hospital (KAUH), a tertiary center in Jeddah, KSA.

RESULTS

In total, 47 patients with GBS (median age: seven years for pediatric and 36 years for adult patients) were included in the current study. There were six male and three female pediatric patients and 19 male and 19 female adult patients. Among patients with GBS who were classified into a specific electrophysiological subtype (n = 28), 13 (46.2%) had acute inflammatory demyelinating polyneuropathy (AIDP), 11 (39%) had an axonal subtype, and four (14%) had Miller Fisher syndrome (MFS). Patients required prolonged hospitalization of approximately 20 ± 22 days (2.83 ± 3.11 weeks). Patients with MFS were more likely to have higher cytoalbuminologic dissociation than those with other subtypes.

CONCLUSION

AIDP was the most frequent type of GBS, followed by the axonal type. Patients required prolonged hospitalization of approximately 20 ± 22 days (2.83 ± 3.11 weeks). Patients with MFS were more likely to have higher cytoalbuminologic dissociation than those with other subtypes. GBS type did not show a relationship with ICU admission or mechanical ventilation use. There was no association between specific therapies and different GBS subtypes and no significant difference in outcomes between different patterns of clinical presentation. Intravenous immunoglobulin (IVIg) and plasma exchange (PE) treatments both had the same efficacy in relation to outcomes for patients with GBS.

Guillain-Barré Syndrome

OBJECTIVE

This article summarizes the clinical features, diagnostic criteria, differential diagnosis, pathogenesis, and prognosis of Guillain-Barré syndrome (GBS), with insights into the current and future diagnostic and therapeutic interventions for this neuromuscular syndrome.

LATEST DEVELOPMENTS

GBS is an acute, inflammatory, immune-mediated polyradiculoneuropathy that encompasses many clinical variants and divergent pathogenic mechanisms that lead to axonal, demyelinating, or mixed findings on electrodiagnostic studies. The type of antecedent infection, the development of pathogenic cross-reactive antibodies via molecular mimicry, and the location of the target gangliosides affect the subtype and severity of the illness. The data from the International GBS Outcome Study have highlighted regional variances, provided new and internationally validated prognosis tools that are beneficial for counseling, and introduced a platform for discussion of GBS-related open questions. New research has been undertaken, including research on novel diagnostic and therapeutic biomarkers, which may lead to new therapies.

ESSENTIAL POINTS

GBS is among the most frequent life-threatening neuromuscular emergencies in the world. At least 20% of patients with GBS have a poor prognosis and significant residual deficits despite receiving available treatments. Research is ongoing to further understand the pathogenesis of the disorder, find new biomarkers, and develop more effective and specific treatments.

[Characteristics of sympathetic skin response in children with Guillain-Barré syndrome]

OBJECTIVES

To explore the value of sympathetic skin response (SSR) in the early diagnosis and prognostic evaluation of Guillain-Barre syndrome (GBS) in children.

METHODS

A retrospective analysis was conducted on the clinical data of 25 children with GBS who were diagnosed from October 2018 to November 2022, and 30 children who were diagnosed with Tourette's syndrome during the same period were selected as the control group. The characteristics of SSR were compared between the two groups, and the association of SSR with autonomic dysfunction (AD), disease severity, and prognosis was analyzed.

RESULTS

The GBS group had a significantly higher abnormal rate of SSR than the control group during the acute phase (P<0.001). SSR combined with early nerve conduction (within 2 weeks after onset) had a sensitivity of 84%, a specificity of 100%, and an accuracy of 93% in the diagnosis of GBS. There were no significant differences in the proportion of AD cases, as well as the Hughes scores during the disease peak, between the abnormal and normal SSR groups (P>0.05). All 7 children with poor short-term prognosis (at 1 month after onset) had abnormal SSR.

CONCLUSIONS

SSR can be used for the early diagnosis of GBS and the monitoring of treatment response in children.

Guillain-Barré Syndrome and COVID-19 Vaccine: A Multicenter Retrospective Study of 46 Cases

ABSTRACT

In the context of the global vaccination campaign against COVID-19, several cases of postvaccinal Guillain-Barré syndrome (GBS) were reported. Whether a causal relationship exists between these events has yet to be established. We investigated the clinical and electromyographic characteristics of patients who developed GBS after COVID-19 vaccination and compare these with findings in patients with GBS, without a history of recent vaccination. We included 91 cases between March 2020 and March 2022, treated at 10 referral hospitals of Buenos Aires, Argentina. Of these, 46 had received vaccination against COVID-19 within the previous month. Although Medical Research Council sum-scores were similar in both groups (median 52 vs. 50; P = 0.4), cranial nerve involvement was significantly more frequent in the postvaccination group (59% vs. 38%; P = 0.02), as was bilateral facial paralysis (57% vs. 24%; P = 0.002). No differences were found in clinical or neurophysiological phenotypes, although 17 subjects presented the variant of bilateral facial palsy with paresthesias (11 vs. 6; P = 0.1); nor were significant differences observed in length of hospital stay or mortality rates. Future vaccine safety monitoring and epidemiology studies are essential to demonstrate any potential causal relationship between these events.

Early electrophysiological study variants and their relationship with clinical presentation and outcomes of patients with Guillain-Barré syndrome

This study compared the clinical outcomes of the two main neurophysiological types of Guillain-Barré Syndrome (GBS). Sixty-two GBS patients were examined clinically at onset using Medical Research Council (MRC), Hughes disability scales (HDS), and nerve conduction studies were evaluated in four limbs. The Modified Erasmus GBS outcome score (MEGOS) was assessed 2 weeks after onset. Outcomes were measured after 3 months using MRC and HDS scores. According to electrophysiological data two main groups identified acute inflammatory demyelinating polyneuropathy (AIDP = 31 cases) or acute axonal GBS including inexcitable forms (26 cases). The number of days between onset of weakness and admission was significantly shorter, and gastrointestinal symptoms were significantly higher among the axonal type than AIDP. MRC sum scores at onset and at nadir were significantly worse in the axonal type than in AIDP. Neck muscle weakness, impaired cough reflex, the need for mechanical ventilation, hypoalbuminemia, and hypernatremia were more common in the axonal type. At outcome, 74% of the AIDP were healthy/minor symptoms versus 38.46% of the axonal type. There was a high prevalence of the axonal variant (41.9%) compared with European and North American populations. The axonal type had a significantly worse outcome than AIDP type.

Case report: A 33 years-old alcoholic male with diarrhea and progressive muscle weakness mimicking Guillain-Barré syndrome

Background

A subacute manifestation of muscle weakness in temporal association with a diarrheal intestinal infection is always suspicious of Guillain-Barré syndrome (GBS). GBS is characterized as an acute inflammatory polyneuroradiculopathy, mediated by cross-reacting autoantibodies and typically triggered by various infections, vaccinations or other causes. Hyponatremia can be associated with GBS and is usually seen in more severe cases. However, the presence of relevant hyponatremia in a case suspicious of GBS can lead to a diagnostic dilemma. We here describe an intriguing and initially misleading case of hyponatremia mimicking GBS, where repeated and thorough electrophysiology was the key to the correct diagnosis.

Case presentation

A 33 years-old man with a history of severe alcohol dependence and schizophrenia developed progressive muscle weakness in the course of a preceding episode of diarrhea. Neurological examination revealed a leg-accentuated tetraplegia with global areflexia. There was also a complex oculomotor dysfunction. Laboratory tests showed hyponatremia of 110 mM. Cerebrospinal-fluid analysis showed a normal cell count and cytological evaluation, protein concentration within the normal range. Electroneurography showed severe proximal nerve conduction block as evidenced by prolonged F-wave latency and distal nerve conduction block as evidenced by prolonged distal motor latencies and reduced motor nerve conduction velocities (NCV) in all peripheral nerves examined. GBS-associated ganglioside autoantibodies were absent. After compensation of hyponatremia alone, muscle weakness improved rapidly and nerve conduction velocity improved similarly. These dynamics are not consistent with GBS and unnecessary immunoglobulin treatment could be avoided.

Conclusion

Suspicion of GBS in the presence of relevant hyponatremia can be misleading as hyponatremia is able to mimic GBS. We demonstrate that repeated and accurate nerve conduction studies together with F-wave diagnostics is helpful to make the correct diagnosis. We discuss the mechanisms of the causes of hyponatremia in GBS and contrast these with the electropyhsiological changes caused by hyponatremia itself. The correct diagnosis will prevent the uncritical use of intravenous immunoglobulins and save unnecessary costs. Also, a possible aggravation of the hyponatremia by immunoglobulin treatment can be averted.

An Analysis of Respiratory Muscle Paralysis of Adult Patients in Guillain-Barré Syndrome: A Retrospective Analysis

Respiratory muscle paralysis is known as a very common complication of Guillain-Barré syndrome (GBS). However, most research has focused on its later stages rather than its earlier stages, including the prognosis of patients with this condition, or factors that act as early predictors of risk. Therefore, our study aimed to identify early predictors of respiratory muscle paralysis in patients with GBS and determine the short-term prognosis of such patients. We recruited 455 GBS patients (age ≥ 18) who had been hospitalized in the First Affiliated Hospital of Harbin Medical University between 2016 and 2021, retrospectively. We recorded clinical and laboratory data and used linear and logistic regression analysis to investigate the relationship between early clinical, examination results, and subsequent respiratory muscle paralysis. Among the 455 patients, 129 were assigned to a respiratory muscle paralysis group and 326 were assigned to a non-respiratory muscle paralysis group. Compared with the non-affected group, the time from onset to admission was shorter (p = 0.0003), and the Medical Research Council (MRC) score at admission and discharge was smaller in the affected group (p < 0.0001). Compared with the non-affected group, the affected group had higher Hughes and Erasmus GBS Respiratory Insufficiency Score (EGRIS) scores at admission and longer hospital stays (p < 0.0001). Patients in the affected group were more likely to have bulbar palsy and lung infections (p < 0.0001). To conclude, bulbar palsy, a higher EGRIS score and Hughes score at admission, a lower MRC score, and a shorter time between onset and admission, are all predictive risk factors for respiratory muscle paralysis in patients with GBS. An increase in any of these factors increases the risk of muscle paralysis. Patients with respiratory muscle paralysis have a poorer short-term prognosis than those without respiratory muscle paralysis. Therefore, we should attempt to identify patients with one or more of these characteristics in the early stages of admission, provide ventilation management, and administer IMV treatment if necessary.

Emerging biomarkers to predict clinical outcomes in Guillain-Barré syndrome

INTRODUCTION

Guillain-Barré syndrome (GBS) is an immune-mediated poly(radiculo)neuropathy with a variable clinical outcome. Identifying patients who are at risk of suffering from long-term disabilities is a great challenge. Biomarkers are useful to confirm diagnosis, monitor disease progression, and predict outcome.

AREAS COVERED

The authors provide an overview of the diagnostic and prognostic biomarkers for GBS, which are useful for establishing early treatment strategies and follow-up care plans.

EXPERT OPINION

Detecting patients at risk of developing a severe outcome may improve management of disease progression and limit potential complications. Several clinical factors are associated with poor prognosis: higher age, presence of diarrhea within 4 weeks of symptom onset, rapid and severe weakness progression, dysautonomia, decreased vital capacity and facial, bulbar, and neck weakness. Biological, neurophysiological and imaging measures of unfavorable outcome include multiple anti-ganglioside antibodies elevation, increased serum and CSF neurofilaments light (NfL) and heavy chain, decreased NfL CSF/serum ratio, hypoalbuminemia, nerve conduction study with early signs of demyelination or axonal loss and enlargement of nerve cross-sectional area on ultrasound. Depicting prognostic biomarkers aims at predicting short-term mortality and need for cardio-pulmonary support, long-term patient functional outcome, guiding treatment decisions and monitoring therapeutic responses in future clinical trials.

Sensitivity and specificity of phrenic nerve electrophysiology to predict mechanical ventilation in the Guillain-Barré syndrome

INTRODUCTION/AIMS

In Guillain-Barré syndrome (GBS), the sensitivity and specificity of phrenic compound muscle action potential (CMAP) measurements to predict endotracheal mechanical ventilation are unknown. Hence, we sought to estimate sensitivity and specificity.

METHODS

We performed a 10-year retrospective analysis of adult GBS patients from our single-center laboratory database (2009 to 2019). The phrenic nerve amplitudes and latencies before ventilation were recorded along with other clinical and demographic features. Receiver operating curve (ROC) analysis with area under the curve (AUC) was used to determine the sensitivity and specificity with 95% confidence interval (CI) for phrenic amplitudes and latencies in predicting the need for mechanical ventilation.

RESULTS

Two hundred five phrenic nerves were analyzed in 105 patients. The mean age was 46.1 ± 16.2 years, with 60% of them being male. Fourteen patients (13.3%) required mechanical ventilation. The average phrenic amplitudes were lower in the ventilated group (P = .003), but average latencies did not differ (P = .133). ROC analysis confirmed that phrenic amplitudes could predict respiratory failure (AUC = 0.76; 95% CI, 0.61 to 0.91; P < .002), but phrenic latencies could not (AUC = 0.60; 95% CI, 0.46 to 0.73; P = .256). The best threshold for amplitude was ≥0.6 mV, with sensitivity, specificity, and positive and negative predictive values of 85.7%, 58.2%, 24.0%, and 96.4%, respectively.

DISCUSSION

Our study suggests that phrenic CMAP amplitudes can predict the need for mechanical ventilation in GBS. In contrast, phrenic CMAP latencies are not reliable. The high negative predictive value of phrenic CMAP amplitudes ≥0.6 mV can preclude mechanical ventilation, making these a useful adjunct to clinical decision-making.

Sympathetic skin response (SSR) in pediatric Guillain-Barré syndrome

Introduction

In the present study, sympathetic skin response (SSR) characteristics were explored in children with Guillain-Barré syndrome (GBS) and the value of early diagnosis and prognostic evaluation in GBS complicated by autonomic dysfunction (AD) was evaluated.

Methods

A total of 25 children with GBS and 30 healthy controls (HCs) were enrolled in this prospective study. SSR findings for the two groups were compared. SSR and nerve conduction study (NCS) results were compared among patients with GBS, and differences in clinical characteristics between the groups with abnormal and normal SSR were analyzed.

Results

Within the GBS group, six patients (24%) required mechanical ventilation, 17 patients (66.7%) had AD, 18 patients (72%) had an abnormal SSR, and 13 patients (52%) had AD combined with SSR abnormalities. There was a statistically significant difference in SSR latency in the lower limbs between the GBS group and HCs (P < 0.05). There was no statistically significant difference between SSR and NCS results in the acute phase of GBS (P > 0.05), and there was no significant difference in the rate of AD or in Hughes functional grade at nadir between the groups with abnormal and normal SSR (P>0.05). However, there was a statistically significant difference between the results of SSR and NCS tests during the recovery phase (P = 0.003). Abnormal SSR mainly occurred in cases of the acute inflammatory demyelinating polyradiculoneuropathy (AIDP) subtype. In addition, SSR was abnormal in all pediatric GBS patients with poor prognosis 1 month after onset of symptoms.

Conclusion

Two-thirds of the children with GBS have AD. SSR could be used for early diagnosis and follow-up of GBS and may also be helpful in evaluating disease severity and short-term prognosis.

CSF Findings in Relation to Clinical Characteristics, Subtype, and Disease Course in Patients With Guillain-Barré Syndrome

BACKGROUND AND OBJECTIVES

To investigate CSF findings in relation to clinical and electrodiagnostic subtypes, severity, and outcome of Guillain-Barré syndrome (GBS) based on 1,500 patients in the International GBS Outcome Study.

METHODS

Albuminocytologic dissociation (ACD) was defined as an increased protein level (>0.45 g/L) in the absence of elevated white cell count (<50 cells/μL). We excluded 124 (8%) patients because of other diagnoses, protocol violation, or insufficient data. The CSF was examined in 1,231 patients (89%).

RESULTS

In 846 (70%) patients, CSF examination showed ACD, which increased with time from weakness onset: ≤4 days 57%, >4 days 84%. High CSF protein levels were associated with a demyelinating subtype, proximal or global muscle weakness, and a reduced likelihood of being able to run at week 2 (odds ratio [OR] 0.42, 95% CI 0.25-0.70; p = 0.001) and week 4 (OR 0.44, 95% CI 0.27-0.72; p = 0.001). Patients with the Miller Fisher syndrome, distal predominant weakness, and normal or equivocal nerve conduction studies were more likely to have lower CSF protein levels. CSF cell count was <5 cells/μL in 1,005 patients (83%), 5-49 cells/μL in 200 patients (16%), and ≥50 cells/μL in 13 patients (1%).

DISCUSSION

ACD is a common finding in GBS, but normal protein levels do not exclude this diagnosis. High CSF protein level is associated with an early severe disease course and a demyelinating subtype. Elevated CSF cell count, rarely ≥50 cells/μL, is compatible with GBS after a thorough exclusion of alternative diagnoses.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that CSF ACD (defined by the Brighton Collaboration) is common in patients with GBS.

Guidelines for Neuroprognostication in Adults with Guillain-Barré Syndrome

BACKGROUND

Guillain-Barré syndrome (GBS) often carries a favorable prognosis. Of adult patients with GBS, 10-30% require mechanical ventilation during the acute phase of the disease. After the acute phase, the focus shifts to restoration of motor strength, ambulation, and neurological function, with variable speed and degree of recovery. The objective of these guidelines is to provide recommendations on the reliability of select clinical predictors that serve as the basis of neuroprognostication and provide guidance to clinicians counseling adult patients with GBS and/or their surrogates.

METHODS

A narrative systematic review was completed using Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Candidate predictors, including clinical variables and prediction models, were selected based on clinical relevance and presence of appropriate body of evidence. The Population/Intervention/Comparator/Outcome/Time frame/Setting (PICOTS) question was framed as follows: "When counseling patients or surrogates of critically ill patients with Guillain-Barré syndrome, should [predictor, with time of assessment if appropriate] be considered a reliable predictor of [outcome, with time frame of assessment]?" Additional full-text screening criteria were used to exclude small and lower quality studies. Following construction of an evidence profile and summary of findings, recommendations were based on four GRADE criteria: quality of evidence, balance of desirable and undesirable consequences, values and preferences, and resource use. In addition, good practice recommendations addressed essential principles of neuroprognostication that could not be framed in PICOTS format.

RESULTS

Eight candidate clinical variables and six prediction models were selected. A total of 45 articles met our eligibility criteria to guide recommendations. We recommend bulbar weakness (the degree of motor weakness at disease nadir) and the Erasmus GBS Respiratory Insufficiency Score as moderately reliable for prediction of the need for mechanical ventilation. The Erasmus GBS Outcome Score (EGOS) and modified EGOS were identified as moderately reliable predictors of independent ambulation at 3 months and beyond. Good practice recommendations include consideration of both acute and recovery phases of the disease during prognostication, discussion of the possible need for mechanical ventilation and enteral nutrition during counseling, and consideration of the complete clinical condition as opposed to a single variable during prognostication.

CONCLUSIONS

These guidelines provide recommendations on the reliability of predictors of the need for mechanical ventilation, poor functional outcome, and independent ambulation following GBS in the context of counseling patients and/or surrogates and suggest broad principles of neuroprognostication. Few predictors were considered moderately reliable based on the available body of evidence, and higher quality data are needed.

Pediatric acute flaccid myelitis: Evaluation of diagnostic criteria and differentiation from other causes of acute flaccid paralysis

BACKGROUND

Acute flaccid paralysis (AFP) is characterized by rapidly progressive limb weakness with low muscle tone. It has a broad differential diagnosis, which includes acute flaccid myelitis (AFM), a rare polio-like condition that mainly affects young children. Differentiation between AFM and other causes of AFP may be difficult, particularly at onset of disease. Here, we evaluate the diagnostic criteria for AFM and compare AFM to other causes of acute weakness in children, aiming to identify differentiating clinical and diagnostic features.

METHODS

The diagnostic criteria for AFM were applied to a cohort of children with acute onset of limb weakness. An initial classification based on positive diagnostic criteria was compared to the final classification, based on application of features suggestive for an alternative diagnosis and discussion with expert neurologists. Cases classified as definite, probable, or possible AFM or uncertain, were compared to cases with an alternative diagnosis.

RESULTS

Of 141 patients, seven out of nine patients initially classified as definite AFM, retained this label after further classification. For probable AFM, this was 3/11, for possible AFM 3/14 and for uncertain 11/43. Patients initially classified as probable or possible AFM were most commonly diagnosed with transverse myelitis (16/25). If the initial classification was uncertain, Guillain-Barré syndrome was the most common diagnosis (31/43). Clinical and diagnostic features not included in the diagnostic criteria, were often used for the final classification.

CONCLUSION

The current diagnostic criteria for AFM usually perform well, but additional features are sometimes required to distinguish AFM from other conditions.

Clinical Profile, Follow-up, and Role of Neuroimaging in Pediatric Guillain-Barré Syndrome in the COVID Era: An Ambispective Study

Background: To define the varied presentations of Guillain-Barré syndrome in children in the COVID era and 6 months' follow-up outcome. Methods: Ambispective study of 15 months' duration involving children with Guillain-Barré syndrome aged 1 month to 18 years at a tertiary care pediatric hospital. They were categorized into groups A and B based on COVID-19 serology testing. Hughes Disability Scale was used for disability assessment. Modified Rankin scale was used for improvement assessment in follow-up. Results: Of 19 children with Guillain-Barré syndrome, 9 (47%) were females and 10 (53%) were males. Groups A and B had children with negative (8) and positive serology (11), respectively. The most common presentation in both groups was motor weakness. Post-COVID pediatric Guillain-Barré syndrome presented with variants of Guillain-Barré syndrome rather than the classical form (P = .03). In group B, patients with elevated inflammatory markers had poor response to intravenous immunoglobulin, and 5 of 11 patients had good response to pulse steroids, probably depicting an inflammation-predominant pathology. Conclusion: Post-COVID Guillain-Barré syndrome in children presented with Guillain-Barré syndrome variants rather than the classic form. Neuroimaging is of great value in both confirming Guillain-Barré syndrome diagnosis and excluding differentials. Patients with elevated inflammatory markers and residual weakness may be given a pulse steroid trial.

Single-cell analysis reveals novel clonally expanded monocytes associated with IL1β-IL1R2 pair in acute inflammatory demyelinating polyneuropathy

Guillain-Barré syndrome (GBS) is an autoimmune disorder wherein the composition and gene expression patterns of peripheral blood immune cells change significantly. It is triggered by antigens with similar epitopes to Schwann cells that stimulate a maladaptive immune response against peripheral nerves. However, an atlas for peripheral blood immune cells in patients with GBS has not yet been constructed. This is a monocentric, prospective study. We collected 5 acute inflammatory demyelinating polyneuropathy (AIDP) patients and 3 healthy controls hospitalized in the First Affiliated Hospital of Harbin Medical University from December 2020 to May 2021, 3 AIDP patients were in the peak stage and 2 were in the convalescent stage. We performed single-cell RNA sequencing (scRNA-seq) of peripheral blood mononuclear cells (PBMCs) from these patients. Furthermore, we performed cell clustering, cell annotation, cell-cell communication, differentially expressed genes (DEGs) identification and pseudotime trajectory analysis. Our study identified a novel clonally expanded CD14+ CD163+ monocyte subtype in the peripheral blood of patients with AIDP, and it was enriched in cellular response to IL1 and chemokine signaling pathways. Furthermore, we observed increased IL1β-IL1R2 cell-cell communication between CD14+ and CD16+ monocytes. In short, by analyzing the single-cell landscape of the PBMCs in patients with AIDP we hope to widen our understanding of the composition of peripheral immune cells in patients with GBS and provide a theoretical basis for future studies.

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.

Sural nerve involvement in Guillain-Barré syndrome: Clinical and prognostic implications. A prospective cohort

BACKGROUND

Sural sparing is common in Guillain-Barré syndrome (GBS). However, one third of patients have sural nerve compromise. Its clinical implications associated factors and short-term prognosis are still unknown. The objective of this study is to identify if sural nerve compromise is associated with a worse prognosis and to describe clinical and electrophysiological characteristics in Guillain-Barré syndrome.

MATERIALS AND METHODS

We prospectively analyzed patients with Guillain-Barré diagnosis with vs without sural nerve compromise. All patients underwent nerve conduction studies within the first 3 days of hospital admission. Clinical and electrophysiological characteristics were compared between groups.

RESULTS

174 patients were included in this study. Acute inflammatory demyelinating polyneuropathy was the predominant variant (43.7 %). Thirty percent of patients had sural nerve involvement. In the comparative analysis between affected vs unaffected sural groups, age ≥50 years and Guillain-Barré disability score ≥3 demonstrated a statistically significant difference. Regarding short-term recovery period for independent walking, there was no significant difference. In the multivariate analysis, age ≥50 years was identified as independent factors for sural nerve compromise on admission.

CONCLUSION

sural nerve compromise occurs in 30 % of patients with GBS and is not associated with a worse functional prognosis. Age ≥50 years was identified as an independent factor for sural nerve compromise.

Study of total duration of distal compound muscle action potential in demyelinating and axonal Guillain-Barre' syndrome

OBJECTIVES

Electrophysiology plays a crucial role in Guillain-Barré syndrome (GBS) diagnosis and subtype classification. The aim of our study was to assess the potential role of distal compound muscle action potential (dCMAP) for early differentiation between acute inflammatory demyelinating polyneuropathy (AIDP) and axonal GBS.

METHODS

We retrospectively reviewed the medical records of 24 subjects with AIDP and 18 subjects with axonal GBS. We built up receiver operating characteristic curves for total dCMAP duration and negative phase of dCMAP duration, in order to derive cut-off values able to differentiate between AIDP and axonal GBS.

RESULTS

The total duration of dCMAP was significantly prolonged in AIDP compared to axonal GBS. AUCs, odds ratio and positive predictive values were higher for total duration than for negative peak duration. Nerve conduction parameters in the lower limbs were more sensitive than those in the upper limbs in distinguishing AIDP from axonal GBS.

DISCUSSION

Total duration of dCMAP dispersion may capture an adjunctive component of distal demyelination, not measured by the more traditional parameters and may thus represent a useful tool for early differentiation between AIDP and axonal GBS.

Neutrophil-to-lymphocyte ratio is a risk indicator of Guillain-Barré syndrome and is associated with severity and short-term prognosis

Introduction

Guillain-Barré syndrome (GBS) is an autoimmune disorder targeting the peripheral nervous system. The neutrophil-to-lymphocyte ratio (NLR), a simple indicator of immune function, is potentially related to its incidence and severity; however, this should be confirmed. We aimed to evaluate the role of NLR in the diagnosis, severity, and prognosis of GBS.

Methods

Data of GBS patients and controls visiting our hospital from January 2010 to December 2020 were retrospectively analyzed (Clinical trial registration: ChiCTR2100053540). Risk factors were determined through logistic regression. Smoothing curves, receiver-operating characteristic curves, and forest plots were drawn.

Results

We included 136 GBS patients and 211 controls. NLR, as a continuous variable, was associated with GBS risk (OR, 2.32; 95% CI, 1.68-3.21; p < 0.001), severe functional disability (OR, 1.23; 95% CI, 1.06-1.43; p = 0.006), severe weakness (OR, 1.19; 95% CI, 1.06-1.35, p = 0.004), and short-term prognosis (OR, 1.21; 95% CI, 1.08-1.36; p = 0.001). NLR was more strongly associated with GBS risk in older (≥60 years) (OR, 7.17; 95% CI, 2.38-21.61) or male (OR, 2.88; 95% CI, 1.78-4.64) patients than in younger (<60 years) (OR, 1.88; 95% CI, 1.37-2.57) or female (OR, 1.85; 95% CI, 1.24-2.77) patients. NLR was significantly associated with severe functional disability in faster disease progression (OR, 1.53; 95% CI, 1.03-12.29) and male patients (OR, 1.41; 95% CI, 1.03-1.92) versus in slower disease progression (OR, 1.12; 95% CI, 0.77-1.64) and female patients (OR, 1.12; 95% CI, 0.77-1.64).

Conclusions

NLR may be an independent GBS risk factor and predictor of severe functional disability, severe weakness, and short-term prognosis.

Identical late motor responses in early Guillain-Barré syndrome: A-waves and repeater F-waves

Electrodiagnostic (EDx) studies play a key role in the investigation of suspected Guillain-Barré syndrome (GBS), providing diagnostic and prognostic information. However, initial EDx findings may not fulfill the neurophysiological criteria for the disease. The aim of this study was to estimate the occurrence and characteristics of A-waves and repeaters F-waves (Freps), both late motor responses identical in latency and configuration, in early stages of GBS. We retrospectively analyzed the initial nerve conduction study (NCS) of 26 GBS patients performed within 10 days from symptom onset. The final subtype diagnosis was acute inflammatory demyelinating polyneuropathy (AIDP) in 16 patients (six met the criteria at the initial EDx study and 10 at follow-up) and acute motor axonal neuropathy (AMAN) in 10 patients (six initially). Identical late responses were commonly found in the majority of nerves (84%). A-waves were present in 59% and an increased frequency of Freps was calculated in 61% of the 105 studied nerves. A-waves morphology (single or complex) could not distinguish between AIDP and AMAN. Nerves with normal NCS had a significantly higher frequency of A-waves, either isolated or in combination with increased index total Freps, as compared to nerves with low compound muscle action potential (CMAP) amplitudes or conduction block. Our findings suggest that both late responses can be useful as early markers of conduction changes of various pathophysiology, being frequently present even prior to abnormalities of CMAP parameters.

Predictors of Mechanical Ventilation in Guillain-Barré Syndrome with Axonal Subtypes

BACKGROUND

The early clinical predictors of respiratory failure in Latin Americans with Guillain-Barré syndrome (GBS) have scarcely been studied. This is of particular importance since Latin America has a high frequency of axonal GBS variants that may imply a worse prognosis.

METHODS

We studied 86 Mexican patients with GBS admitted to the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, a referral center of Mexico City, to describe predictors of invasive mechanical ventilation (IMV).

RESULTS

The median age was 40 years (interquartile range: 26-53.5), with 60.5% men (male-to-female ratio: 1.53). Most patients (65%) had an infectious antecedent (40.6% gastrointestinal). At admission, 38% of patients had a Medical Research Council (MRC) sum score <30. Axonal subtypes predominated (60.5%), with acute motor axonal neuropathy being the most prevalent (34.9%), followed by acute inflammatory demyelinating polyneuropathy (32.6%), acute motor sensory axonal neuropathy (AMSAN) (25.6%), and Fisher syndrome (7%). Notably, 15.1% had onset in upper limbs, 75.6% dysautonomia, and 73.3% pain. In all, 86% received either IVIg (9.3%) or plasma exchange (74.4%). IMV was required in 39.5% patients (72.7% in AMSAN). A multivariate model without including published prognostic scores yielded the time since onset to admission <15 days, axonal variants, MRC sum score <30, and bulbar weakness as independent predictors of IMV. The model including grading scales yielded lower limbs onset, Erasmus GBS respiratory insufficiency score (EGRIS) >4, and dysautonomia as predictors.

CONCLUSION

These results suggest that EGRIS is a good prognosticator of IMV in GBS patients with a predominance of axonal electrophysiological subtypes, but other early clinical data should also be considered.

Long-term outcomes of plasma exchange versus intravenous immunoglobulin for the treatment of Guillain-Barré Syndrome: A double-blind, randomized clinical trial

Background

Most previous studies comparing the effectiveness of Plasma Exchange (PE) or intravenous immunoglobulin (IVIG) in treating Guillain-Barre syndrome (GBS) have focused on the short-term outcome at around 1 month.

Objective

To compare the long-term efficacy of PE and IVIG at one year in adult patients with GBS.

Methods

Eighty-one adult patients with acute GBS were randomized into two groups with a ratio of 2 : 1: PE (N = 54) and IVIG (N = 27). Patients were assessed with the Medical Research Council sum score (MRC sum score), GBS Disability Scale (GDS), and Functional assessment of acute inflammatory neuropathy (FAAIN) at baseline, ten days, one month, three months, and one year. Neurophysiological examinations were performed at baseline and three months following treatment.

Results

There were no significant differences between groups in demographic, clinical, and laboratory data. Both treatments produced a significant improvement in all clinical rating scales in both groups that continued up to one year. There were significant differences in the time course of recovery in the MRC and FAAIN scales, with significantly more improvement in the IVIG group at 1 and 3 months, although there was no significant difference in outcome at one year. However the effect size showed measurable differences between the PE and IVIG groups across the different measures at one-year. Electrophysiological studies showed equal improvement in most measures in both groups at three months, with a slightly greater effect in the IVIG group.

Conclusion

long term outcomes of IVIG and PE were equivalent. However the effect size showed measurable differences between the PE and IVIG groups across the different measures at one-year follow-up that indicate the superiorty of IVIG. There was also a tendency for improvement to be slightly faster in the IVIG group.

Nationwide survey of childhood Guillain-Barré syndrome, Fisher syndrome, and Bickerstaff brainstem encephalitis in Japan

OBJECTIVE

Guillain-Barré syndrome (GBS), Fisher syndrome (FS), and Bickerstaff brainstem encephalitis (BBE) are immune-mediated neuropathies presenting with symptoms such as weakness, ophthalmoplegia, ataxia, and consciousness disturbances. Although the epidemiology of GBS and BBE in patients of all ages has been reported, childhood data have not been well-investigated. We aimed to determine the clinical features, therapeutics, and prognoses of childhood GBS, FS, and BBE in Japan.

METHODS

We sent questionnaires to 1068 pediatric neurologists in Japan from 2014 to 2016 to determine the number of children less than 15 years old with GBS, FS, or BBE and their age and sex. We subsequently performed a secondary survey to investigate the clinical features, laboratory data, treatment, and prognosis.

RESULTS

Five-hundred thirty-eight pediatric neurology specialists (50.4%) responded to the first survey. The total number of children with GBS, FS, and BBE in Japan from 2014 to 2016 were 87, 10, and 6, respectively. GBS was classified as acute inflammatory demyelinating neuropathy (35.6%), acute motor axonal neuropathy (20.7%), or acute motor-sensory axonal neuropathy (10.3%), with a male-to-female ratio of 1.29:1.0 and a wide distribution of onset ages. The disease severities of GBS, FS, and BBE were variable, but all children could walk within one year.

CONCLUSION

The prognoses of childhood GBS, FS, and BBE were generally favorable, as long as the patient was promptly treated with either intravenous immunoglobulin or plasma exchange.

Critical illness-associated weakness and related motor disorders

Weakness of limb and respiratory muscles that occurs in the course of critical illness has become an increasingly common and serious complication of adult and pediatric intensive care unit patients and a cause of prolonged ventilatory support, morbidity, and prolonged hospitalization. Two motor disorders that occur singly or together, namely critical illness polyneuropathy and critical illness myopathy, cause weakness of limb and of breathing muscles, making it difficult to be weaned from ventilatory support, commencing rehabilitation, and extending the length of stay in the intensive care unit, with higher rates of morbidity and mortality. Recovery can take weeks or months and in severe cases, and may be incomplete or absent. Recent findings suggest an improved prognosis of critical illness myopathy compared to polyneuropathy. Prevention and treatment are therefore very important. Its management requires an integrated team approach commencing with neurologic consultation, creatine kinase (CK) measurement, detailed electrodiagnostic, respiratory and neuroimaging studies, and potentially muscle biopsy to elucidate the etiopathogenesis of the weakness in the peripheral and/or central nervous system, for which there may be a variety of causes. These tenets of care are being applied to new cases and survivors of the coronavirus-2 disease pandemic of 2019. This chapter provides an update to the understanding and approach to critical illness motor disorders.

Acute comitant strabismus in anti-GQ1b antibody syndrome

Ophthalmoplegia is the diagnostic hallmark of anti-GQ1b antibody syndrome. This study aimed to define the patterns of acute comitant strabismus in patients with anti-GQ1b antibody syndromes. We retrospectively analyzed the ocular motor findings in 84 patients with anti-GQ1b antibody-associated ophthalmoplegia during the acute phases. Of the 84 patients, 11 (13%) showed acute comitant strabismus. Compared to those without, patients with acute comitant strabismus frequently showed abnormal ocular motor findings that included gaze-evoked (n = 8), spontaneous (n = 4) and positional nystagmus (n = 4), saccadic hypermetria (n = 3), head-shaking nystagmus (n = 2), pulse-step mismatch (n = 1), and impaired visual cancellation of the vestibulo-ocular reflex (n = 1, p < 0.001). On the contrary, iridoplegia (p = 0.029) and ptosis (p = 0.001) were more commonly observed in patients with paralytic (incomitant) strabismus than in those with acute comitant strabismus. Comitant strabismus can manifest during the acute phase of anti-GQ1b antibody syndromes in association with other central ocular motor abnormalities. These findings implicate that the cerebellum and/or brainstem can be the primary target of the anti-GQ1b antibodies.

A case of Guillain-Barré syndrome related to COVID-19 infection

BACKGROUND

After the first COVID-19 case, reported neurological complications are increasing day by day.

METHOD

In this paper, we present a benign-course Guillain-Barré syndrome (GBS) emerging 2 weeks after COVID-19 infection in a 35-years-old male.

RESULTS

Cough and fever were started 18 days ago and his PCR test was resulted positive for COVID-19 infection. After treatment and quarantine were completed, he developed sudden leg weakness following autonomic features. Cerebrospinal fluid was suggestive for GBS despite the electrodiagnostic test was not helpful because it was done in the first days. He recovered without needing any immunotherapy.

CONCLUSION

Our case suggested that COVID-19 can cause atypical benign GBS forms in addition to well-known variants. Comprehensive studies are needed to describe the unknowns and determine the exact prevalence of GBS after COVID-19 infection, including mild cases that did not require hospital admission.

Acute/chronic inflammatory polyradiculoneuropathy

Autoimmune neuropathy may present acutely or with a more progressive and/or relapsing and remitting course. Acute inflammatory neuropathy or Guillain-Barré syndrome (GBS) has variable presentations but by far the most common is acute inflammatory demyelinating polyradiculoneuropathy which is characterized by rapidly progressive proximal and distal symmetric weakness, sensory loss, and depressed reflexes. The most common chronic autoimmune neuropathy is chronic inflammatory demyelinating polyradiculoneuropathy, which in its most typical form is clinically similar to acute inflammatory demyelinating polyradiculoneuropathy (proximal and distal symmetric weakness, sensory loss, and depressed reflexes) but differs in that onset is much more gradual, i.e., over at least 8 weeks. While the majority of GBS cases result from a postinfectious activation of the immune system, presumably in a genetically susceptible host, less is understood regarding the etiopathogenesis of chronic inflammatory demyelinating polyradiculoneuropathy. Both acute and chronic forms of these inflammatory neuropathies are driven by some combination of innate and adaptive immune pathways, with differing contributions depending on the neuropathy subtype. Both disorders are largely clinical diagnoses, but diagnostic tools are available to confirm the diagnosis, prognosticate, detect variant forms, and rule out mimics. Given the autoimmune underpinnings of both disorders, immunosuppressive and immunomodulating treatments are typically given in both diseases; however, they differ in their response to treatment.

Exploratory factor analysis determines latent factors in Guillain-Barré syndrome

Exploratory factor analysis (EFA) has been developed as a powerful statistical procedure in psychological research. EFA's purpose is to identify the nature and number of latent constructs (= factors) underlying a set of observed variables. Since the research goal of EFA is to determine what causes the observed responses, EFA is ideal for hypothesis-based studies, such as identifying the number and nature of latent factors (e.g., cause, risk factors, etc.). However, the application of EFA in the biomedical field has been limited. Guillain-Barré syndrome (GBS) is peripheral neuropathy, in which the presence of antibodies to glycolipids has been associated with clinical signs. Although the precise mechanism for the generation of anti-glycolipid antibodies is unclear, we hypothesized that latent factors, such as distinct autoantigens and microbes, could induce different sets of anti-glycolipid antibodies in subsets of GBS patients. Using 55 glycolipid antibody titers from 100 GBS and 30 control sera obtained by glycoarray, we conducted EFA and extracted four factors related to neuroantigens and one potentially suppressive factor, each of which was composed of the distinct set of anti-glycolipid antibodies. The four groups of anti-glycolipid antibodies categorized by unsupervised EFA were consistent with experimental and clinical findings reported previously. Therefore, we proved that unsupervised EFA could be applied to biomedical data to extract latent factors. Applying EFA for other biomedical big data may elucidate latent factors of other diseases with unknown causes or suppressing/exacerbating factors, including COVID-19.

Diagnostic Pitfalls in Guillain-Barré Syndrome: Case Report and Literature Review

Guillain-Barré syndrome (GBS) represents a group of acute immune-mediated polyradiculoneuropathies that is usually characterized by symmetrical limb weakness and areflexia. GBS can also lead to atypical clinical findings, which may lead to confusion and errors in the diagnosis. In this report, we describe a case of Guillain-Barré syndrome in a 7-year-old child who presented with neck stiffness, headache and vomiting mimicking acute meningoencephalitis, arthritis and myositis. Symptoms of ascending paralysis developed subsequently. Clearly, the atypical presentation of GBS is a significant dilemma for pediatricians and may lead to delays in diagnosis and treatment.