Factors contributing to delay in diagnosis of Guillain-Barré syndrome and impact on clinical outcome

New chronic inflammatory demyelinating polyneuropathy/Guillain-Barré syndrome guidelines - impact on clinical practise

PURPOSE OF REVIEW

There is no diagnostic biomarker that can reliably detect Guillain-Barré syndrome (GBS) or chronic inflammatory demyelinating polyneuropathy (CIDP). Diagnosis relies upon integrating key clinical characteristics and relevant supportive data. Consequently, misdiagnosis and delayed diagnosis are common. Diagnostic criteria have proven valuable resources to improve diagnosis, but are underutilized during routine clinical care.

RECENT FINDINGS

In 2021, the EAN/PNS CIDP criteria was published, and were followed by the EAN/PNS GBS criteria in 2023. Both guidelines utilized GRADE methodology to formulate evidence-based recommendations that are intended to be used by adult and paediatric clinicians across diverse care settings to optimize diagnostic accuracy and improve patient outcomes during routine clinical care.

SUMMARY

The EAN/PNS GBS and CIDP criteria detail specific clinical, electrophysiological, and laboratory features that raise diagnostic confidence, and call attention to diagnostic mimics. The sensitivity of EAN/PNS and other modern criteria to detect GBS and CIDP is high, but utilization during clinical practice is low. Complexity is one factor limiting widespread application. Strategies are needed to optimize criteria adoption during routine clinical care such that GBS and CIDP diagnosis can be achieved with greater speed and accuracy.

Comparison of Clinical Features, Short-Term Outcome of Guillain-Barré Syndrome Between Adults and Children: A Retrospective Study in Vietnam

BACKGROUND

Despite extensive research on Guillain-Barré syndrome (GBS) in adults and children, there is a lack of comparison regarding short-term outcomes in various age groups. Our study aims to elucidate the differences in clinical features and short-term outcomes in Vietnam.

METHODS

After retrospective data collection, we compared clinical features in patients with GBS aged ≤16 years at Children's Hospital 2 and aged >16 years at University Medical Center Ho Chi Minh City from 2017 to 2021. A positive short-term outcome was recorded if patients had a GBS Disability Score of 0 to 2 at hospital discharge.

RESULTS

We analyzed 109 adults (58.7% males; mean age 50.6 ± 17.7) and 111 children (58.6% males; mean age 7.2 ± 4.9). Comparable antecedent infection and immunization incidence in both groups were observed (35.8% vs 45.9%, P > 0.05). Pain and sensory disturbance were the most common onset symptom in adults (57.8%), whereas lower limb weakness predominated in children (61.3%). Ophthalmoplegia (18.3% vs 5.4%), pain, sensory disturbance (85.3% vs 67.6%), ataxia (33.0% vs 15.3%) were more prevalent in adults (P < 0.05). The axonal subtype was prominent in both adults (51.4%) and children (53.2%). Patients were classified into: classic GBS (49.5% and 68.5%), GBS variants (11.0% and 15.3%), classic Miller Fisher syndrome (MFS) (1.8% and 1.8%), MFS variants (2.8% and 0%), and GBS/MFS overlap (34.9% and 14.4%). Short-term outcomes did not significantly differ based on age.

CONCLUSIONS

Age-related variations in clinical features were observed, but adults and children exhibited similar short-term functional outcomes.

Diagnostic odyssey of Guillain-Barré syndrome in children

BACKGROUND AND OBJECTIVES

A gap exists between difficulty in diagnosis and importance of early recognition and intervention in pediatric Guillain-Barré syndrome (GBS). Therefore, this study aimed to establish a diagnostic odyssey plot that allows "at-a-glance" overview of the diagnostic odyssey of GBS in children, including overall diagnostic delay, physician-related and patient-related diagnostic delays, and length and frequency of diagnostic errors.

METHODS

In this single-center retrospective cohort study, standardized data were obtained from children with GBS from 2003 to 2020. Overall diagnostic delay (time between symptom onset and diagnosis), physician-related diagnostic delay (time between the first medical visit and diagnosis), and patient-related diagnostic delay (time between symptom onset and the first medical visit) were analyzed.

RESULTS

The study examined a total of 21 patients (11 men, median age 4.5 years). Overall, there were 40 misdiagnoses among 17 patients, while four were diagnosed correctly at the first visit. The overall diagnostic delay was 9 days [interquartile range (IQR), 6-17 days]. Physician-related diagnostic delay, but not patient-related diagnostic delay, was correlated with the overall diagnostic delay. Patients in the late-diagnosed group were more frequently misdiagnosed during their diagnostic odyssey than patients in the other groups. Risk factors associated with diagnostic delay included delayed onset of weakness and sensory deficits, absence of swallowing problems, and misdiagnosis as orthopedic disorders or viral infections.

DISCUSSION

A unique diagnostic odyssey exists in pedaitric GBS. Several clinical risk factors were associated with the diagnostic delay.

High risk and low prevalence diseases: Guillain-Barré syndrome

INTRODUCTION

Guillain-Barré syndrome (GBS) is a rare but serious condition that carries with it a high rate of morbidity and mortality.

OBJECTIVE

This review highlights the pearls and pitfalls of GBS, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence.

DISCUSSION

GBS is a rare immune-mediated neurologic disorder with peripheral nerve injury. It most commonly presents weeks after a bacterial or viral infection, though there are a variety of associated inciting events. The diagnosis is challenging and often subtle, as only 25-30% of patients are diagnosed on their initial healthcare visit. Clinicians should consider GBS in patients with progressive ascending weakness involving the lower extremities associated with hyporeflexia, but the cranial nerves, respiratory system, and autonomic system may be involved. While the ED diagnosis should be based on clinical assessment, further evaluation includes laboratory testing, cerebrospinal fluid (CSF) analysis, and potentially neuroimaging. Not all patients demonstrate albumino-cytological dissociation on CSF testing. Several criteria exist to assist with diagnosis, including the National Institute of Neurological Disorders and Stroke criteria and the Brighton criteria. Management focuses first on assessment of the patient's hemodynamic and respiratory status, which may require emergent intervention. Significant fluctuations in heart rate and blood pressure may occur, and respiratory muscle weakness may result in the need for airway protection. Neurology consultation is recommended, and definitive treatment includes PLEX or IVIG.

CONCLUSIONS

An understanding of GBS can assist emergency clinicians in diagnosing and managing this potentially deadly disease.

Neuropathic Pain in the Emergency Setting: Diagnosis and Management

Neuropathic pain, traditionally considered a chronic condition, is increasingly encountered in the emergency department (ED), accounting for approximately 20% of patients presenting with pain. Understanding the physiology and key clinical presentations of neuropathic pain is crucial for ED physicians to provide optimal treatment. While diagnosing neuropathic pain can be challenging, emphasis should be placed on obtaining a comprehensive medical history and conducting a thorough clinical examination. Patients often describe neuropathic pain as a burning or shock-like sensation, leading them to seek care in the ED after ineffective relief from common analgesics such as paracetamol and NSAIDs. Collaboration between emergency medicine specialists, neurologists, and pain management experts can contribute to the development of evidence-based guidelines specifically tailored for the emergency department setting. This article provides a concise overview of the common clinical manifestations of neuropathic pain that may prompt patients to seek emergency care.

Diagnostic windows in non-neoplastic diseases: a systematic review

BACKGROUND

Investigating changes in prediagnostic healthcare utilisation can help identify how much earlier conditions could be diagnosed. Such 'diagnostic windows' are established for cancer but remain relatively unexplored for non-neoplastic conditions.

AIM

To extract evidence on the presence and length of diagnostic windows for non-neoplastic conditions.

DESIGN AND SETTING

A systematic review of studies of prediagnostic healthcare utilisation was carried out.

METHOD

A search strategy was developed to identify relevant studies from PubMed and Connected Papers. Data were extracted on prediagnostic healthcare use, and evidence of diagnostic window presence and length was assessed.

RESULTS

Of 4340 studies screened, 27 were included, covering 17 non-neoplastic conditions, including both chronic (for example, Parkinson's disease) and acute conditions (for example, stroke). Prediagnostic healthcare events included primary care encounters and presentations with relevant symptoms. For 10 conditions, sufficient evidence to determine diagnostic window presence and length was available, ranging from 28 days (herpes simplex encephalitis) to 9 years (ulcerative colitis). For the remaining conditions, diagnostic windows were likely to be present, but insufficient study duration was often a barrier to robustly determining their length, meaning that diagnostic window length may exceed 10 years for coeliac disease, for example.

CONCLUSION

Evidence of changing healthcare use before diagnosis exists for many non-neoplastic conditions, establishing that early diagnosis is possible, in principle. In particular, some conditions may be detectable many years earlier than they are currently diagnosed. Further research is required to accurately estimate diagnostic windows and to determine how much earlier diagnosis may be possible, and how this might be achieved.

Atypical Guillain-Barré syndrome presenting with fluctuating weakness

Guillain-Barré Syndrome (GBS) is an immune-mediated polyneuropathy, most often occurring within weeks of an infection. Cases of COVID-19-related GBS have been reported, and the typical presentation is a progressive ascending paralysis. We describe a case of a 40-year-old with recent symptomatic COVID-19 who presented with atypical GBS findings, hand weakness that progressed to tetraplegia within 24 hours. He had hyperreflexia on his initial exam and did not meet diagnostic criteria for GBS. Inconsistent neurological findings with spontaneous improvement of symptoms, unremarkable initial evaluation including lumbar puncture, and anxiety further complicated the diagnosis. On day 6, he was intubated for diaphragmatic paralysis, and repeat lumbar puncture showed albumin-cytologic dissociation. Intravenous immunoglobulin followed by plasmapheresis improved strength and allowed for extubation. This case highlights the difficulty of recognizing heterogenic GBS presentations.

Old age and multiple comorbidity are associated with delayed diagnosis of Guillain-Barre syndrome

To assess whether older age and presence of comorbidities were associated with a delayed diagnosis of Guillain-Barré syndrome (GBS). The medical records of 140 patients diagnosed with GBS at Severance Hospital from March 2011 to December 2020 were retrospectively reviewed. Comorbidity profiles were assessed using the Charlson comorbidity index (CCI). The age-adjusted CCI (ACCI) score was calculated, which further incorporated the effect of age. Patients were classified into the early diagnosis group (diagnosis duration ≤ 14 days) and late diagnosis group (diagnosis duration > 14 days). Clinical features and comorbidity profiles were compared between the two groups. The cumulative incidence of diagnosis was compared between the low and high ACCI groups. Age was significantly higher in the late diagnosis group (61.8 ± 15.0 years) than in the early diagnosis group (49.1 ± 18.4, p = 0.001). The CCI score was higher in the late diagnosis group (≥ 3 in 26.1%) than in the early diagnosis group (≥ 3 in 5.1%, p = 0.01). The ACCI score demonstrated a positive correlation with the diagnosis duration (β = 1.636, p < 0.001), indicating that the diagnosis was delayed in patients with a higher ACCI score. The duration from onset to diagnosis was longer in the high ACCI group than in the low ACCI group (log-rank test, p < 0.001). The diagnosis duration was significantly longer, especially in patients with malignancy and cardiovascular diseases. Delayed diagnosis of GBS is associated with older age and multiple comorbidities. Diagnostic delay was significant in patients with malignancies and cardiovascular diseases. Early suspicion of GBS is required in these patients.

Causes and consequences of diagnostic delay in Guillain-Barré syndrome in a U.K. tertiary centre

INTRODUCTION/AIMS

Understanding the potential causes and consequences of diagnostic delay in Guillain-Barré syndrome (GBS) could improve quality of care and outcomes. We aimed to determine these.

METHODS

We retrospectively reviewed records of subjects with GBS, admitted to our centre at University Hospitals Birmingham, U.K., between January 2005 and December 2020. We evaluated time to diagnosis from presentation, factors associated with diagnostic delay and its potential consequences.

RESULTS

We included 119 consecutive subjects. Diagnostic delay >5 days from first presentation occurred in 27/119 (22.7%) of patients. Diagnostic delay was associated with age >60 years (OR: 3.58; 95% CI: 1.44-8.85), pre-existing cardiac/respiratory disease (OR: 4.10; 95% CI: 1.46-11.54), pre-existing diabetes (OR: 10.38; 95% CI: 2.47-43.69), documented normal initial neurological examination (OR: 2.49; 95% CI: 1.03-6.02), initial assessment by primary care (OR: 3.33; 95% CI: 1.22-9.10) and >1 visit for medical attention (OR: 10.29; 95% CI: 3.81-27.77). Diagnostic delay was not associated with length of in-patient stay, ICU admission, ventilation, ability to walk at discharge, or in-patient mortality. Independent associations with diagnostic delay were observed for >1 visit for medical attention (OR: 10.15; 95% CI: 3.64-28.32) and pre-existing cardiac/respiratory disease (OR: 3.98; 95% CI: 1.19-13.28). An association of diagnostic delay with in-patient mortality was ascertained specifically in subjects with classic GBS (OR: 5.33; 95% CI: 1.1-25.87).

DISCUSSION

Diagnostic delay in GBS results from patient-specific factors and patient pathways. A high index of suspicion is appropriate for certain patient groups. Prospective studies are needed to further investigate this topic. This article is protected by copyright. All rights reserved.

Disease and Patient Characteristics Contributing to Diagnostic Delays in Patients With Guillain-Barré Syndrome

Introduction: Diagnosis of Guillain Barre syndrome (GBS) is often made clinically. Certain patient and disease characteristics can cause delays in diagnosis and management.

Methods: Observational retrospective study of forty-four patients diagnosed with GBS either clinically, cerebrospinal fluid analysis, and/or by electro-diagnostic criteria at a teaching hospital (University of Missouri Hospital) in Columbia, Mid-Missouri between 2011 and 2017.

Results: Patients with coexisting neurological conditions had statistically significant delay in diagnosis of GBS [Mean (SD); 13 ± 5 vs. 9.39 ± 4.7; p = 0.03]. Patients presenting with motor + symptoms (sensory and/or autonomic, in addition to motor), compared to those with only motor symptoms had statistically significant delay in diagnosis of GBS [Mean (SD); 11.90 ± 5 vs. 8.58 ± 4; p = 0.04].

Discussion: Presence of co-existing neurological conditions, and motor + symptoms can delay timely diagnosis and management of GBS.

Guillain-Barre syndrome in 220 patients with COVID-19

This review summarises and discusses recent findings concerning the pathophysiology, clinical presentation, diagnosis, treatment, and outcome of SARS-CoV-2-associated Guillain-Barre syndrome (SC2-GBS). By the end of December 2020, at least 220 patients with SC2-GBS have been published in 95 papers. SC2-GBS is most likely secondary due to an immune reaction against SARS-CoV-2 since the virus has not been found in the CSF of any SC2-GBS patient so far reported. SC2-GBS occurs in each age group and does not differ from non-SC2-GBS regarding clinical presentation and treatment, but the outcome of SC2-GBS is worse compared to non-CS2-GBS patients, and the prevalence/incidence of GBS most likely increased since the outbreak of the pandemic. Early diagnosis of SC2-GBS is warranted to apply appropriate treatment in due time and to improve the overall outcome from the infection.

Patients' experiences and perceptions of Guillain-Barré syndrome: A systematic review and meta-synthesis of qualitative research

Background

Guillain-Barré syndrome (GBS) is an immune-mediated polyradiculoneuropathy, with an incidence of 1-2/100,000 per year. Its severity is variable, ranging from very mild cases with brief weakness to severe paralysis, leading to inability to breathe independently, or even death. Currently there is limited evidence exploring the experiences of GBS patients. The aim of this study was to review patients’ experiences and perceptions of GBS and its variants at diagnosis, discharge and during recovery, by conducting a systematic review and thematic meta-synthesis of qualitative studies of patients’ experiences of GBS (and its variants).

Methods

We searched twelve electronic databases, supplemented with internet searches and forward and backward citation tracking from the included studies and review articles. Data were synthesised thematically following the Thomas and Harden approach. The CASP Qualitative Checklist was used to assess the quality of the included studies of this review.

Results

Our search strategy identified a total of 5,282 citations and after removing duplicates and excluding citations based on title and abstract, and full-text screening, five studies were included in the review and meta-synthesis; all included studies were considered of acceptable quality. Through constant discussions and an iterative approach, we developed six analytical themes following a patient’s journey from suspecting that they had a health problem, through to being hospitalised, experiencing ongoing difficulties, slowly recovering from GBS, adjusting to their new circumstances, and re-evaluating their lives.

Conclusions

Despite the variety of experiences, it was evident from all included studies that being diagnosed with and surviving GBS was a life-changing experience for all participants.

Trial registration

Protocol was registered (CRD42019122199) on the International Prospective Register of Systematic Reviews (http://www.crd.york.ac.uk/PROSPERO).

Spinal nerve involvement in early Guillain-Barré syndrome: The Haymaker and Kernohan's legacy

Pathological studies of early Guillain-Barré syndrome (GBS), defined as of 10days of disease onset, are scanty making it difficult to interpret the physiopathology of clinical and electrophysiological features. In 1949, Webb Haymaker and James Kernohan reported 50 clinico-pathological studies of fatal GBS cases, 32 of them having died between days 2 and 10 after onset. They established that the brunt of initial lesions, consisting of endoneurial oedema interpreted as degenerative, relied on spinal nerves. That this oedema was inflammatory was soon thereafter recognized. Two decades later, however, the pathogenic role of endoneurial oedema was disputed. In experimental allergic neuritis, considered an animal model of GBS, the initial lesion appearing on day 4 post-inoculation is marked inflammatory oedema in the sciatic nerve and lumbosacral nerve roots. Additional detailed clinico-pathological studies corroborated that the appearance of epi-perineurium at the subarachnoid angle, where anterior and posterior roots join to form the spinal nerve, is a pathological hotspot in early GBS, there developing inflammatory oedema, incipient demyelination and endoneurial ischemic zones with axonal degeneration. Furthermore, nerve ultrasonography has demonstrated predominant spinal nerve changes in early GBS, either demyelinating or axonal. Other outstanding Haymaker and Kernohan's contributions were to clarify the complex nosology of the syndrome bringing under the same rubric Landry's paralysis, acute febrile polyneuritis and GBS, and critically analyzing GBS exclusion criteria by then prevailing. It is concluded that the authors' legacy remains as relevant as ever.

Bilateral Ptosis due to Sympathetic Dysfunction as a Feature of Guillain-Barre Syndrome

This case-control study demonstrates that bilateral ptosis due to ocular sympathetic dysfunction is a characteristic feature of Guillain-Barre syndrome (GBS) and apraclonidine can be helpful in unmasking this clinical feature. Five patients with GBS and 9 healthy controls were assessed for ocular sympathetic dysfunction through application of topical apraclonidine to 1 eye. Changes resulting from reversal of ptosis or miosis due to apraclonidine were compared with the eye on the other side with no apraclonidine using photographs. Ocular sympathetic dysfunction in the form of mild bilateral ptosis was found in all 5 patients with GBS recruited in this study. Consistent with previous reports, healthy subjects had no significant response to apraclonidine. Although there was evidence of concomitant pupillary dysfunction in the form of bilateral Horner syndrome in 2 of the patients with GBS with more severe GBS phenotype, this study did not have the statistical power to reach conclusions regarding pupillary dysfunction and disease severity in GBS.

[Focal point emergency departments]

The number of patients treated in hospital emergency departments in Germany has risen in recent years to approximately 20 million. This escalation also applies to the increasing numbers of patients presenting with neurological symptoms and diseases, which occur in approximately 20 % of emergency patients. In addition to patients with stroke, inflammatory or degenerative central nervous system (CNS) and peripheral nervous system (PNS) disorders who need urgent treatment, more and more patients with nonspecific complaints or conditions attend emergency departments for elective treatment, not least because timely appointments with specialist neurologists in practices could not be obtained. Neurological expertise and presence in emergency departments at the level of specialist standard are therefore indispensable for providing a professional level of treatment, which also corresponds to current legal requirements. The implementation of a generalist emergency physician in Germany, as introduced in some European countries, would mean a retrograde step for neurological expertise in emergency admission management. The discipline of neurology must work together with other emergency disciplines to improve the financing of emergency departments and provide neurologists working there with a substantive curriculum of further and continuing education in emergency-related aspects of neurology. The discipline of neurology has a responsibility to emergency patients within its range of competencies and must, therefore, strengthen and improve its role in healthcare politics and concerning organizational and personnel aspects of neurological emergencies.

The consequences of Campylobacter infection

PURPOSE OF REVIEW

The purpose of this review is to provide an update on the clinical, public health and economic consequences of Campylobacter infection.

RECENT FINDINGS

Campylobacter is a leading bacterial cause of food-related illness. Its importance is enhanced by the chronic sequelae that can result from acute infection. Recent advances include a new clinical classification system for neurological sequelae with the aim of speeding accurate diagnosis and appropriate treatment, a better understanding of the mechanisms underlying postinfectious functional gastrointestinal disorders, the emergence of Campylobacter concisus and Campylobacter showae as potential aetiological agents in inflammatory bowel disease, a new mechanism for antimicrobial resistance in campylobacters and a better appreciation of the economic costs.

SUMMARY

Campylobacter infection is very common and can lead to serious chronic sequelae and considerable personal, healthcare and societal costs.

Clinical Heterogeneity of Guillain-Barré Syndrome in the Emergency Department: Impact on Clinical Outcome

Guillain-Barré syndrome (GBS) is mainly classified into acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN). Although diagnosis of GBS requires progressive weakness and universal areflexia or hyporeflexia, cases of GBS with preserved or increased deep tendon reflexes (DTRs) have been increasingly recognized. We report three cases of GBS, presenting at a single unit in six months. Our first case presented with pure sensory symptoms. The second case had nonspecific generalized weakness, while the third presented with typical ascending weakness. One of our patients had preserved DTRs, while the other two had increased DTRs. Our two cases with hyperreflexia were found to have a preceding Campylobacter jejuni infection and anti-ganglioside antibodies, and their electrophysiological studies revealed AMAN. The other case had an AIDP. Only one case was offered a diagnosis and treatment from the first emergency department (ED) visit and had a better clinical outcome. Clinical diagnosis of GBS in the ED can be challenging. Delay in diagnosis of GBS in the ED is common due to cases with intact or increased DTRs, atypical pattern of weakness, or pure sensory symptoms. Emergency physicians should be aware of GBS clinical heterogeneity, because early diagnosis and treatment improve clinical outcome.

Celiac disease diagnosis still significantly delayed - Doctor's but not patients' delay responsive for the increased total delay in women

BACKGROUND

There is insufficient data on diagnostic delay and associated factors in celiac disease (CeD) as well as on its potential impact on the course of disease.

METHODS

Specifically taking its two components - patients' and doctors' delay - into account, we performed a large systematic patient survey study among unselected CeD patients in Switzerland.

RESULTS

We found a mean/median total diagnostic delay of 87/24 months (IQR 5-96), with a range from 0 up to 780 months and roughly equal fractions of patients' and doctors' delay. Both mean/median total (93.1/24 vs. 60.2/12, p<0.001) and doctors' (41.8/3 vs. 23.9/2, p<0.001) diagnostic delay were significantly higher in female vs. male patients, whereas patients' delay was similar, regardless of preceding irritable bowel syndrome diagnosis. Patients with a diagnostic delay shorter than 2 years were significantly less often in need of steroids and/or immunosuppressants, substitution for any nutritional deficiency but more often free of symptoms 6 and 12 months after diagnosis.

CONCLUSIONS

There is a substantial diagnostic delay in CeD, which is associated with a worse clinical outcome and significantly longer in female patients. This increased diagnostic delay in women is due to doctors' but not patients' delay and cannot be explained by antecedent IBS prior to establishing the CeD diagnosis.

Proximal nerve lesions in early Guillain-Barré syndrome: implications for pathogenesis and disease classification

Guillain-Barré syndrome (GBS) is an acute-onset, immune-mediated disorder of the peripheral nervous system. In early GBS, arbitrarily established up to 10 days of disease onset, patients could exhibit selective manifestations due to involvement of the proximal nerves, including nerve roots, spinal nerves and plexuses. Such manifestations are proximal weakness, inaugural nerve trunk pain, and atypical electrophysiological patterns, which may lead to delayed diagnosis. The aim of this paper was to analyze the nosology of early GBS reviewing electrophysiological, autopsy and imaging studies, both in acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor/motor-sensory axonal neuropathy (AMAN/AMSAN). Early electrophysiology showed either well-defined demyelinating or axonal patterns, or a non-diagnostic pattern with abnormal late responses; there may be attenuated M responses upon lumbar root stimulation as the only finding. Pathological changes predominated in proximal nerves, in some studies, most prominent at the sides where the spinal roots unite to form the spinal nerves; on very early GBS endoneurial inflammatory edema was the outstanding feature. In the far majority of cases, spinal magnetic resonance imaging showed contrast enhancement of cauda equina, selectively involving anterior roots in AMAN. Both in AIDP and AMAN/AMSAN, ultrasonography has demonstrated frequent enlargement of ventral rami of C5-C7 nerves with blurred boundaries, whereas sonograms of upper and lower extremity peripheral nerves exhibited variable and less frequent abnormalities. We provide new insights into the pathogenesis and classification of early GBS.