Severe axonal degeneration in acute Guillain-Barré syndrome: evidence of two different mechanisms?

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.

Guillain-Barré syndrome post-SARS-CoV-2 vaccine: a systematic review and data analysis on its clinical, laboratory, electrophysiological, and radiological features

Introduction

Guillain-Barré syndrome (GBS) is a rare disease that affects almost 0.8-1.9 cases per 100,000 people worldwide every year. This is the most prevalent cause of subacute flaccid paralyzing illness today. It is a subacute inflammatory demyelinating polyradiculoneuropathy; the typical scenario involves ascending symmetrical flaccid paralysis, but in some circumstances, sensory, autonomic, and cranial neuropathy may also be involved. Several vaccines have been found to have complications since the previous century. Numerous case reports of GBS in the literature have been reported following COVID-19 vaccines in recent times.

Objective

This study aimed to conduct a comprehensive examination of GBS cases that have been reported after COVID-19 vaccines; to analyze the descriptive statistical analysis of data gathered regarding clinical, laboratory, electrophysiological, and radiological characteristics; to discuss, based on the available evidence, whether the disease has a preference for a particular vaccine type; and to speculate on the potential pathogenesis.

Methodology

This review has been carried out by recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

Result

Reviewing 60 case reports illustrated that most of them are from the USA (18.1%) and the majority of affected individuals were males (60%). The results favored the association between vector-based SARS-CoV-2 vaccine, particularly AstraZeneca vaccine, and the GBS. The mean of symptoms onset is 11.4 days. The results of diagnostic tests such as LP are consistent mostly with albumin-cytological dissociation (81.81%), where brain and spine MRI was unremarkable in 59.52%. Regarding electrodiagnostic tests, AIDP is the most common variant (61.81%). The management was not consistent among the case reports. However, IVIG is the most frequent way of treating these patients (68.33%). The functional outcome was documented in 47 patients; 65% improved with medical management.

Conclusion

This study aimed to conduct a systematic review of reported cases of GBS following COVID-19 vaccines and descriptive statistical analysis of collected data on clinical, laboratory, electrophysiological, and radiological features, to discuss, based on available results, whether the disease has a predilection to a specific vaccine type and to speculate the potential pathogenesis.

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.

Ability Realization Improves During Inpatient Rehabilitation for Guillain-Barré Syndrome

OBJECTIVE

The aim of the study was to investigate improvement in ability realization and additional long-term outcomes, during and after inpatient rehabilitation for Guillain-Barré syndrome.

DESIGN

This is a retrospective, longitudinal cohort study, in which outcomes were examined using validated scales, for 47 inpatients with Guillain-Barré syndrome.

RESULTS

Scores improved from 65 on the American Spinal Injury Association Motor Score and 50 on the Spinal Cord Independence Measure, at admission to inpatient rehabilitation, to 81 and 80 at discharge, and to 92 and 95 at the end of 7.5 yrs, on average, at the follow-up ( P = 0.001). The mean Spinal Cord Independence Measure/American Spinal Injury Association Motor Score ratio, which reflects the ability realization, increased during rehabilitation from 50/65 to 80/81 ( P = 0.001), and tended to increase further at follow-up to 95/92 ( P = 0.228). At follow-up, pain did not correlate, and fatigue showed a weak correlation with the American Spinal Injury Association Motor Score, Spinal Cord Independence Measure, and the Adult Subjective Assessment of Participation ( r = -0.363, P = 0.012; r = -0.362, P = 0.012; r = -0.392, P = 0.006).

CONCLUSIONS

Ability realization improved during inpatient rehabilitation for Guillain-Barré syndrome and remained high after discharge, suggesting a likely contribution of rehabilitation to the functional outcome, beyond the contribution of neurological recovery. Despite residual fatigue and pain, there was only minor or no effect on daily function or participation.

Characteristics of Guillain-Barre Syndrome Patient Underwent Hyperbaric Oxygen Therapy at Lakesla 2016–2019

BACKGROUND: Guillain-Barre syndrome (GBS) is considered an acute immune-mediated monophasic illness. Standard therapy includes intravenous immunoglobulin (IVIG) and/or plasmapheresis. Yet, long-standing disability remains a problem. In Indonesia, the availability and cost of these therapies are constraints. AIM: To show the capability of hyperbaric oxygen (HBO2) therapy in GBS patients who did not undergo standard therapy. HBO2 also provides healing in patients who experience delays in therapy. METHODS: Data included identity, demographic, social history, current disease history, disease progression and therapies used. Data were displayed in the form of tables and graphs. RESULTS: Twenty-five GBS patients underwent HBO2 from 2016 to 2019. The majority of patients were males aged 20-30 years, triggered by preceding diarrhea. After approximately three to ten days following HBO2, they felt their first positive changes. They walked with assistance after two to three weeks receiving HBO2 and without assistance after four to 12 weeks receiving HBO2. CONCLUSION: HBO2 administration show clinical improvement in GBS patients. HBO2 is expected to become an adjuctive therapy for GBS patients in Indonesia.

Pain in acute motor axonal neuropathy

INTRODUCTION/AIMS

Patients with acute motor axonal neuropathy (AMAN) generally have pure motor neuropathy and clinicians usually do not link pain with AMAN. The aim of this retrospective study was to describe the character, location, and intensity of pain in AMAN and acute inflammatory demyelinating polyneuropathy (AIDP) in the acute phase.

METHODS

This was a retrospective study in 44 patients with Guillain-Barré syndrome (GBS) having progressive weakness of more than one limb. The information, including the demographic characteristics, preceding infections, clinical symptoms and signs, severity at nadir, the characteristics of pain, use of analgesics, laboratory and electrophysiological data, and the medical treatment for GBS, were collected from the medical records.

RESULTS

In 44 patients, 40.9% were diagnosed as AMAN, and 34.1% as AIDP. Pain was more prevalent in AMAN (76.5%) than in AIDP (26.7%, P = .02). Low back and extremities were the most common locations of pain in AMAN (7/13 and 7/13, respectively) and AIDP (2/4 and 2/4, respectively).

DISCUSSION

Pain was a common symptom in AMAN in the acute stage. The presence or absence of pain is not useful for distinguishing AIDP from AMAN.

Acute motor axonal neuropathy after ipilimumab and nivolumab treatment in melanoma brain metastases: A case report and review of the literature

The use of immune checkpoint inhibitors including ipilimumab and nivolumab has expanded for several tumors including melanoma brain metastasis. These have resulted in a growing spectrum of neurologic immune-related adverse events, including ones that are rare and difficult to diagnose and treat. Here, we present a patient with melanoma brain metastasis who was treated with immune checkpoint inhibitors and developed an Acute Motor Axonal Neuropathy. To our knowledge, this is the first case of Acute Motor Axonal Neuropathy as an immune-related adverse event associated with combination treatment of ipilimumab and nivolumab, who was successfully treated. A 28-year-old woman with metastatic BRAF V600E melanoma developed melanoma brain metastasis and was enrolled on Checkmate 204, a Phase 2 clinical trial using ipilimumab (3 mg/kg intravenous) and nivolumab (1 mg/kg intravenous) every 3 weeks for four cycles, followed by monotherapy with nivolumab (240 mg intravenous) every 2 weeks. A few days after Cycle 2 of ipilimumab and nivolumab, she developed a pure motor axonal neuropathy consistent with Acute Motor Axonal Neuropathy. She was treated with several immunosuppressive treatments including high dose methylprednisolone, immune globulin, and infliximab, and her motor neuropathy eventually improved several months after onset of symptoms. Unfortunately, she had progression of her systemic disease and died several months later. This is the first case reported of Acute Motor Axonal Neuropathy associated with ipilimumab and nivolumab, successfully treated with immune-suppressive therapy. As the field of immunotherapy expands with the increasing use of the immune checkpoint inhibitors, it is critical to increase our knowledge and understanding of the neurologic immune-related adverse events associated with immune checkpoint inhibitors. This includes the spectrum of rare neurologic immune-related adverse events, which can be quite difficult to recognize and treat. Early consultations with neurology may expedite a diagnosis and treatment plan in patients with unexplained weakness receiving immune checkpoint inhibitor therapy.

Guillain-Barré syndrome after adoptive cell therapy with tumor-infiltrating lymphocytes

BACKGROUND

Adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TILs) is a promising experimental immunotherapy that has shown high objective responses in patients with melanoma. Current protocols use a lymphodepletive chemotherapy before infusion of ex vivo expanded TILs, followed by high-dose interleukin-2 (IL-2). Treatment-related toxicities are mainly attributable to the chemotherapy regimen and to the high-dose IL-2 and are generally reversible. Neurological side effects have rarely been described. Nevertheless, due to improvements in cell production techniques and due to combinations with other immunomodulating molecules, side effects not previously described may be encountered.

CASE PRESENTATION

We report the case of a 53-year-old heavily pretreated patient with melanoma who developed Guillain-Barré syndrome (GBS) 19 days after ACT using autologous TILs, given in the context of a phase I trial. He presented with dorsal back pain, unsteady gait and numbness in hands and feet. Lumbar puncture showed albuminocytological dissociation, and nerve conduction studies revealed prolonged distal motor latencies in median, ulnar, tibial and peroneal nerves, compatible with a GBS. The patient was treated with intravenous immunoglobulins and intensive neurological rehabilitation, with progressive and full recovery at 21 months post-TIL-ACT. Concomitant to the onset of GBS, a cytomegalovirus reactivation on immunosuppression was detected and considered as the most plausible cause of this neurological side effect.

CONCLUSION

We describe for the first time a case of GBS occurring shortly after TIL-ACT for melanoma, even though we could not identify with certainty the triggering agent. The report of such rare cases is of extreme importance to build on the knowledge of immune cellular therapies and their specific spectrum of toxicities.

Axonal degeneration in Guillain-Barré syndrome: a reappraisal

The aim of this review was to analyse the pathophysiology of axonal degeneration in Guillain-Barré syndrome (GBS) with emphasis on early stages (≤ 10 days after onset). An overview of experimental autoimmune neuritis (EAN) models is provided. Originally GBS and acute inflammatory demyelinating polyneuropathy were equated, presence of axonal degeneration being attributed to a "bystander" effect. Afterwards, primary axonal GBS forms were reported, designated as acute motor axonal neuropathy/acute motor-sensory axonal neuropathy. Revision of the first pathological description of axonal GBS indicates the coexistence of active axonal degeneration and demyelination in spinal roots, and pure Wallerian-like degeneration in peripheral nerve trunks. Nerve conduction studies are essential for syndrome subtyping, though their sensitivity is scanty in early GBS. Serum markers of axonal degeneration include increased levels of neurofilament light chain and presence of anti-ganglioside reactivity. According to nerve ultrasonographic features and autopsy studies, ventral rami of spinal nerves are a hotspot in early GBS. In P₂-induced EAN models, the initial pathogenic change is inflammatory oedema of spinal roots and sciatic nerve, which is followed by demyelination, and Wallerian-like degeneration in nerve trunks possessing epi-perineurium; a critical elevation of endoneurial fluid pressure is a pre-requisite for inducing ischemic axonal degeneration. Similar lesion topography may occur in GBS. The repairing role of adaxonal Schwann cytoplasm in axonal degeneration is analysed. A novel pathophysiological mechanism for nerve trunk pain in GBS, including pure motor forms, is provided. The potential therapeutic role of intravenous boluses of methylprednisolone for early severe GBS and intractable pain is argued.

Clinical features of Guillain-Barré syndrome patients with elevated serum creatine kinase levels

Background

It is not well defined whether Guillain–Barré syndrome (GBS) patients with elevated serum creatine kinase (CK) levels have characteristic clinical features and are related to the subgroups of GBS.

Methods

We retrospectively studied 51 consecutive patients with GBS, who visited our hospital, and compared clinical, laboratory and electrophysiological findings between patients with and without elevated CK levels.

Results

Of 51 patients, 14 patients (27%) showed an elevation of serum CK levels. When compared with patients with the normal CK levels, the ratios of male, antecedent infections, and anti-GM1 antibody positivity were significantly higher in patients with elevated CK levels. The ratios of hypoesthesia, cranial nerve involvement, and urinary retention were significantly less in patients with elevated CK levels. There were no significant differences in disability at peak between two groups. In the electrophysiological examination, sensory nerve abnormalities were not observed. Although some patients with elevated CK levels showed prolongation of distal motor latencies (DMLs) and increase of durations in the initial examination, development of the prolongation of DMLs and increase of durations was not observed in the follow-up examinations. The findings were consistent with acute motor axonal neuropathy (AMAN) with reversible conduction failure (RCF) but not acute inflammatory demyelinating polyneuropathy (AIDP).

Conclusions

The results suggest that the GBS patients with elevated CK levels represent not a group of AIDP but a group of AMAN with axonal degeneration or RCF even though the initial electrophysiological examination shows AIDP pattern.

Early clinicopathologic description of nodoparanodopathy in the 19th century

Nodoparanodopathy is a recent concept in the field of peripheral neuropathy, corresponding to peripheral nerve disorders stemming from an autoimmune attack directed and limited to the nodal region. This concept was identified using modern techniques of electrophysiology, immunology, and pathology (including electron microscopy). We present here what we believe to be the earlier well-documented case of nodoparanodopathy in the medical literature, based on an article written by Samuel Gilbert Webber (1838–1926) in 1884.

Role of IV Immunoglobulin in Indian Children With Guillain-Barré Syndrome

OBJECTIVES

To evaluate the outcome of Indian children with Guillain-Barré syndrome who received IV immunoglobulin compared with those who did not receive any specific therapy.

DESIGN

Single center, prospective cross-sectional study.

SETTING

Tertiary care neurology teaching hospital.

PATIENTS

Children (≤ 18 yr old) with Guillain-Barré syndrome were included from a prospectively maintained Guillain-Barré syndrome registry from January 2008 to April 2017. Children were classified into acute inflammatory demyelinating polyradiculoneuropathy, acute motor axonal neuropathy, acute motor-sensory axonal neuropathy, and inexcitable motor nerves based on nerve conduction study.

INTERVENTIONS

Out of 138 pediatric Guillain-Barré syndrome, 50 received IV immunoglobulin and another 50 age and peak disability matched controls (who did not receive IV immunoglobulin or plasmapheresis) were selected from the same registry for comparison.

MEASUREMENTS AND MAIN RESULTS

Outcome at 3 and 6 months was defined on the basis of a 0-10 Clinical Grading Scale into complete (Clinical Grading Scale < 3), partial (Clinical Grading Scale 3-5), and poor (Clinical Grading Scale > 5) recovery. The primary outcome was proportion of patients with complete recovery at 3 and 6 months in IV immunoglobulin and non-IV immunoglobulin groups. Secondary outcomes included in-hospital deaths, duration of mechanical ventilation, and hospital stay. Subgroup analysis was done in acute motor axonal neuropathy and acute inflammatory demyelinating polyradiculoneuropathy groups. The baseline characteristics were similar except for shorter duration of illness and higher proportion of facial palsy in IV immunoglobulin group. Hospital deaths, duration of mechanical ventilation, hospital stay, and outcome at 3 and 6 months were not different between the two groups. Children with acute motor axonal neuropathy had better recovery at 6 months on IV immunoglobulin (58.3% vs 11.1%; p = 0.03), but not those with acute inflammatory demyelinating polyradiculoneuropathy (58.3% vs 72.2%; p = 0.22). In nonambulatory Guillain-Barré syndrome children, complete recovery at 6 months was similar in IV immunoglobulin and non-IV immunoglobulin group (57.4% vs 57.1%; p = 0.98).

CONCLUSIONS

In Indian children with Guillain-Barré syndrome, the outcome at 6 months in IV immunoglobulin treated group was similar to non-IV immunoglobulin group. Children with acute motor axonal neuropathy responded better to IV immunoglobulin.

Clinical electrophysiology of axonal polyneuropathies

Axonal neuropathies encompass a wide range of acquired and inherited disorders with electrophysiologic characteristics that arise from the unique neurophysiology of the axon. Accurate interpretation of nerve conduction studies and electromyography requires an in-depth understanding of the pathophysiology of the axon. Here we review the unique neurophysiologic properties of the axon and how they relate to clinical electrodiagnostic features. We review the length-dependent Wallerian or "dying-back" processes as well as the emerging body of literature from acquired axonal neuropathies that highlights the importance of axonal disease at the nodes of Ranvier. Neurophysiologic features of individual inherited and acquired axonal diseases, including primary nerve disease as well as systemic immune mediated, metabolic, and toxic diseases involving the peripheral nerve, are reviewed. This comprehensive review of electrodiagnostic findings coupled with the current understanding of pathophysiology will aid the clinician in the evaluation of axonal polyneuropathies.

Guillain-Barré Syndrome

Guillain-Barré syndrome (GBS) is an acute immune-mediated polyradiculoneuropathy, and pathophysiologically classified into acute inflammatory demyelinating polyneuropathy (AIDP), acute motor axonal neuropathy (AMAN), and acute motor and sensory axonal neuropathy (AMSAN). The main pathophysiological mechanism is complement-mediated nerve injury caused by antibody-antigen interaction in the peripheral nerves. Antiglycolipid antibodies are most pathogenic factors in the development of GBS, but not found in 40% of patients with GBS. One of the principal target regions in GBS is the node of Ranvier where functional molecules including glycolipids are assembled. Nodal dysfunction induced by the immune response in nodal axolemma, termed "nodopathy," can electrophysiologically show reversible conduction failure, axonal degeneration, or segmental demyelination. To detect new target molecules in antiglycolipid antibody-negative GBS and to elucidate the pathophysiology in the subacute and the subsequent phases of the disorder are the next problems.

Egos has a reduced capacity to predicts GBS prognosis in Northeast Brazil

OBJECTIVE

The Erasmus Guillain Barre Outcome Score (EGOS) is a prognostic model that predicts the chance of being able to walk independently at 6 months after Guillain Barré syndrome (GBS). This study was conducted aiming to determine the validity of EGOS in a Brazilian population.

MATERIAL AND METHODS

Data collected from GBS patients in Rio Grande do Norte, Brazil, were used to determine the validity of EGOS. GBS disability score was assessed in the second week of disease and at 6 months.

RESULTS

A total of 206 subjects were studied. The Brazilian patients were younger, with a more severe clinical presentation, with higher percentage of cranial nerve involvement and upper respiratory infection. There was no difference relative to sex or presence of anti-gangliosides antibodies. The demyelinating variant was more common (73.9%). However, only 24% of the Brazilians with EGOS 5.5-7 were not able to walk after 6 months, compared to 52% to European Group. Nine patients (3.8%) presented nodopathies, of these four had an EGOS >5, but only one of the latter group was unable to walk after 6 months of GBS.

CONCLUSIONS

Erasmus Guillain Barre Outcome Score was not a good predictor for the ability to walk after 6 months of GBS in Rio Grande do Norte, Brazil. Differences could be that the Brazilian GBS were younger, or alternatively, it could be due to a different infection profile or in the incidence of nodopathies.

Atypical Electrophysiological Findings in a Patient with Acute Motor and Sensory Axonal Neuropathy

Guillain–Barré syndrome (GBS) is an immune-mediated polyradiculoneuropathy with acute onset and rapid clinical worsening; early diagnosis and immunomodulating therapy can ameliorate the course of disease. During the first days, however, nerve conduction studies (NCSs) are not always conclusive. Here, we describe a 73-year-old man presenting with progressive muscular weakness of the lower limbs, ascending to the upper limbs, accompanied by distal sensory disturbances. Neuroimaging of brain and spine and NCSs were unremarkable; cerebrospinal fluid analysis revealed no albuminocytologic dissociation. Based on typical clinical features, and on positivity for serum GD1b-IgM antibodies, GBS with proximal conduction failure at multiple radicular levels was postulated, and a standard regime of intravenous immunoglobulin was administered. Four weeks later, the patient presented with flaccid tetraparesis, areflexia, and reduction of position sense, tingling paresthesias, and initial respiratory distress. Repeat NCS still revealed almost normal findings, except for the disappearance of right ulnar nerve F-waves. A few days thereafter, the patient developed severe respiratory insufficiency requiring mechanical ventilation for 2 weeks. On day 50, NCS revealed for the first time markedly reduced compound muscle action potentials and sensory nerve action potentials in all tested nerves, without signs of demyelination; needle electromyography documented widespread denervation. The diagnosis of acute motor and sensory axonal neuropathy was made. After 3 months of intensive rehabilitation, the patient regained the ability to walk with little assistance and was discharged home. In conclusion, normal NCS findings up to several weeks do not exclude the diagnosis of GBS. Very proximal axonal conduction failure with late distal axonal degeneration should be taken into consideration, and electrodiagnostic follow-up examinations, even employing unusual techniques, are recommended over several weeks after disease onset.

Guillain-Barré syndrome

Guillain-Barré syndrome is the most common and most severe acute paralytic neuropathy, with about 100,000 people developing the disorder every year worldwide. Under the umbrella term of Guillain-Barré syndrome are several recognisable variants with distinct clinical and pathological features. The severe, generalised manifestation of Guillain-Barré syndrome with respiratory failure affects 20-30% of cases. Treatment with intravenous immunoglobulin or plasma exchange is the optimal management approach, alongside supportive care. Understanding of the infectious triggers and immunological and pathological mechanisms has advanced substantially in the past 10 years, and is guiding clinical trials investigating new treatments. Investigators of large, worldwide, collaborative studies of the spectrum of Guillain-Barré syndrome are accruing data for clinical and biological databases to inform the development of outcome predictors and disease biomarkers. Such studies are transforming the clinical and scientific landscape of acute autoimmune neuropathies.

Serial electrophysiological findings in Guillain-Barré syndrome not fulfilling AIDP or AMAN criteria

Guillain-Barré syndrome (GBS) is categorized into two major subtypes: acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN). However, a proportion of patients are electrophysiologically unclassified because of electrophysiological findings that do not fulfil AIDP or AMAN criteria, and underlying pathophysiological mechanisms and lesion distributions of unclassified patients are not well defined. The aims of this study are to elucidate disease pathophysiology and lesion distribution in unclassified patients. We retrospectively studied 48 consecutive GBS patients. Patients were classified on the basis of initial electrophysiological findings according to Ho's criteria. Clinical and serial electrophysiological examinations of unclassified patients were conducted. Twelve (25 %) GBS patients were unclassified. All unclassified patients were able to walk independently at 21 days after onset. No unclassified patients, except one patient with diabetes mellitus, had sensory nerve involvement. Eight patients underwent a follow-up study within 15 days of the initial study. Distal motor latencies (DMLs) of the left median motor nerve were found to be significantly and uniformly decreased compared with initial studies (p = 0.008). DMLs (p < 0.0001) and distal compound action potential (CMAP) durations (p = 0.002) of all nerves were significantly decreased, and distal CMAP amplitudes (p = 0.026) significantly increased compared with initial studies. In unclassified GBS patients, DML values during initial electrophysiological studies would be prolonged compared with expected values in the same patient unaffected by GBS and later improve rapidly with increased distal CMAP amplitudes without the development of excessive temporal dispersions. Lesions are also present in distal nerve segments caused by reversible conduction failure.

Serial peripheral nerve ultrasound in Guillain-Barré syndrome

OBJECTIVE

To assess the longitudinal changes of nerve ultrasound in Guillain-Barré syndrome (GBS) patients.

METHODS

We prospectively recruited 17 GBS patients and 17 age and gender-matched controls. Serial studies of their nerve conduction parameters and nerve ultrasound, documenting the cross-sectional areas (CSA), were performed at admission and repeated at several time points throughout disease course.

RESULTS

Serial nerve ultrasound revealed significantly enlarged CSA in median, ulnar and sural nerves within the first 3 weeks of disease onset. Longitudinal evaluation revealed an improvement in the nerve CSA with time, reaching significance in the ulnar and sural nerves after 12 weeks. There was no significant difference between the demyelinating and axonal subtypes. There was also no significant correlation found between nerve CSA and neurophysiological parameters or changes in nerve CSA and muscle strength.

CONCLUSION

In GBS, serial studies of peripheral nerve ultrasound CSA are helpful to detect a gradual improvement in the nerve size.

SIGNIFICANCE

Serial nerve ultrasound studies could serve as a useful tool in demonstrating nerve recovery in GBS.

Electrophysiological diagnosis of Guillain-Barré syndrome subtype: could a single study suffice?

BACKGROUND

Serial electrophysiology has been suggested as essential for accurate diagnosis in Guillain-Barré syndrome (GBS). However, whether more adapted electrophysiological criteria may allow a single study to be sufficient is unknown.

METHODS

We retrospectively reviewed records of 365 consecutive patients with GBS from Birmingham, U.K., and Garches, France, admitted between 1998 and 2013. Electrophysiology was analysed using existing criteria as well as a set of modified criteria, developed using sensitive and specific cut-off values for demyelination and incorporating new knowledge on electrophysiology of axonal GBS. We compared diagnostic rates and classification changes using modified criteria with published literature relating to serial studies.

RESULTS

With existing criteria, we found similar proportions of acute inflammatory demyelinating polyradiculoneuropathy (AIDP) (71.5% vs. 72%; p=1), axonal GBS (17.5% vs. 14.7%; p=0.62) and equivocal forms (9.9% vs. 13.3%; p=0.41) to the previous studies considered. With modified criteria, we identified comparable rates of AIDP (56.2% vs. 58.7%; p=0.70), axonal GBS (35.1% vs. 36%; p=0.89) and equivocal forms (7.7% vs. 5.3%; p=0.63) with a single nerve conduction study as compared with when serial electrophysiology was used in previous analyses. We observed an identical diagnostic shift from AIDP to axonal GBS with modified criteria as that described with serial studies (21.5% vs. 18.5%; p=0.72). Classification changes with modified criteria correlated significantly with performing of electrophysiology ≤7 days after symptom onset (p=0.045), indicating their greater usefulness in earlier disease stages.

CONCLUSIONS

A single electrophysiological study may suffice to establish the ultimate electrodiagnosis of GBS subtype if the proposed modified electrodiagnostic criteria are used.

Simulation of Brain Death from Fulminant De-efferentation

Background:

Guillain-BarrÈ syndrome (GBS) classically presents with a subacutely evolving areflexic paralysis, with typical laboratory findings of elevated cerebrospinal fluid protein and abnormal nerve conduction studies. There is now an increasing recognition of GBS variants that differ in clinical presentation, prognosis, electrophysiology and presumed pathogenesis. Fulminant cases of GBS have been reported in which a rapid deterioration evolves to a clinical state resembling ìbrain deathî.

Methods:

A retrospective analysis of two such cases of fulminant neuropathy are described, that includes the clinical course, electrophysiology and neuropathology where available.

Results:

We describe two patients that presented with a rapid course of neurological deterioration, lapsing into what resembled a ìclinically brain-deadî state that was subsequently ascribed to a fulminant polyneuropathy. Investigations (electrophysiological, pathological) and the clinical course suggested an axonal neuropathy.

Conclusion:

A fulminant neuropathy can result in a clinical state resembling ìbrain deathî through diffuse de-efferentation. Although generally attributed to aggressive demyelination with secondary axonal degeneration, a primary axonopathy can also lead to a similar clinical presentation.

Changes in lymphocyte subsets in patients with Guillain-Barré syndrome treated with immunoglobulin

Background

Guillain-Barré syndrome (GBS) is an autoimmune condition characterized by peripheral neuropathy. The pathogenesis of GBS is not fully understood, and the mechanism of how intravenous immunoglobulin (IVIG) cures GBS is ambiguous. Herein, we investigated lymphocyte subsets in patients with two major subtypes of GBS (acute inflammatory demyelinating polyneuropathy, AIDP, and acute motor axonal neuropathy, AMAN) before and after treatment with IVIG, and explored the possible mechanism of IVIG action.

Methods

Sixty-four patients with GBS were selected for our study and divided into two groups: AIDP (n = 38) and AMAN (n = 26). Thirty healthy individuals were chosen as the control group. Relative counts of peripheral blood T and B lymphocyte subsets were detected by flow cytometry analysis.

Results

In the AIDP group, the percentage of CD4⁺CD45RO⁺ T cells was significantly higher, while the percentage of CD4⁺CD45RA⁺ T cells was notably lower, than in the control group. After treatment with IVIG, the ratio of CD4⁺/CD8⁺ T cells and the percentage of CD4⁺CD45RA⁺ T cells increased, while the percentages of CD8⁺ T cells and CD4⁺CD45RO⁺ T cells decreased significantly, along with the number of CD19⁺ B cells. However, there were not such obvious changes in the AMAN group. The Hughes scores were significantly lower in both the AIDP and AMAN groups following treatment with IVIG, but the changes in Hughes scores showed no significant difference between the two groups.

Conclusions

This study suggested that the changes in T and B-lymphocyte subsets, especially in CD4⁺T-lymphocyte subsets, might play an important role in the pathogenesis of AIDP, and in the mechanism of IVIG action against AIDP.

Neurophysiological approach to disorders of peripheral nerve

Disorders of the peripheral nerve system (PNS) are heterogeneous and may involve motor fibers, sensory fibers, small myelinated and unmyelinated fibers and autonomic nerve fibers, with variable anatomical distribution (single nerves, several different nerves, symmetrical affection of all nerves, plexus, or root lesions). Furthermore pathological processes may result in either demyelination, axonal degeneration or both. In order to reach an exact diagnosis of any neuropathy electrophysiological studies are crucial to obtain information about these variables. Conventional electrophysiological methods including nerve conduction studies and electromyography used in the study of patients suspected of having a neuropathy and the significance of the findings are discussed in detail and more novel and experimental methods are mentioned. Diagnostic considerations are based on a flow chart classifying neuropathies into eight categories based on mode of onset, distribution, and electrophysiological findings, and the electrophysiological characteristics in each type of neuropathy are discussed.

Electrodiagnostic criteria for Guillain-Barrè syndrome: a critical revision and the need for an update

Electrophysiology plays a determinant role in Guillain-Barré syndrome (GBS) diagnosis, classification of the subtypes and in establishing prognosis. In the last three decades, different electrodiagnostic criteria sets have been proposed for acute inflammatory demyelinating neuropathy (AIDP), acute motor axonal neuropathy (AMAN) and acute motor and sensory axonal neuropathy (AMSAN). Criteria sets for AIDP varied for the parameters indicative of demyelination considered, for the cut-off limits and the number of required abnormalities (all a priori established) showing different sensitivities. Criteria sets for AMAN and AMSAN were proposed on the initial assumption that these subtypes were pathologically characterised by simple axonal degeneration. However, some AMAN patients show transient conduction block/slowing in intermediate and distal nerve segments, mimicking demyelination but without the development of abnormal temporal dispersion, named reversible conduction failure (RCF). The lack of distinction between RCF and demyelinating conduction block leads to fallaciously classify AMAN patients with RCF as AIDP or AMAN with axonal degeneration. Serial electrophysiological studies are mandatory for proper diagnosis of GBS subtypes, identification of pathophysiological mechanisms and prognosis. More reliable electrodiagnostic criteria should be devised to distinguish axonal and demyelinating subtypes of GBS, taking into consideration the RCF pattern and focussing on temporal dispersion.

Immunopathology and Th1/Th2 immune response of Campylobacter jejuni-induced paralysis resembling Guillain-Barré syndrome in chicken

Immunopathogenesis of Campylobacter jejuni-associated Guillain-Barré syndrome (GBS) is not yet well established probably due to lack of experimental model. Therefore, we studied the Th1/Th2 immune response and pathological changes in C. jejuni-induced chicken model for GBS. C. jejuni (5 × 10(9) CFU/ml) and placebo were fed to 30 chickens each. Stools of all birds were negative for C. jejuni by culture and PCR before experiment. The birds were regularly assessed for disease symptoms up to 30 days. Sciatic nerves from all chickens were examined at 5 days intervals by histopathology and immunohistochemistry, and also for the expression of Th1/Th2 cytokines. Twenty-two chickens (73.3%) developed diarrhea after C. jejuni infection; 18 (60.0%) experimental chickens developed GBS-like paralytic neuropathy. Pathology in the sciatic nerves of these chickens included perinodal and/or patchy demyelination, perivascular focal lymphocytic infiltration, myelin swelling and presence of macrophages within the nerve fibers on 10th-20th post-infection day (PID). Cytokines (IFN-γ, IL-1β, TNF-α, IL-6 and IL-2) were elevated in early phase (5th-15th PID) and TGF-β2, IL-10 and IL-4 in the recovery phase (25th-30th PID) of the disease. The study provides evidence that C. jejuni infection in the chicken can provide an experimental animal model of GBS.

Influence of critical illness on axonal loss in Guillain-Barré syndrome

In this study we sought to determine whether axonal damage in severe Guillain-Barré syndrome (GBS) was secondary to critical illness polyneuropathy (CIP) in the intensive care unit (ICU) by reviewing comorbidities in patients who had initial and follow-up electromyographic (EMG) studies. Patients were classified as demyelinating (EMG-D) or axonal (EMG-A) according to findings on the second EMG. A critical illness (CI) score, derived from components of the APACHE II score, assessed the severity of critical illness in the ICU. Forty-one patients were admitted to the ICU and had a follow-up EMG. Of these, 28 (68%) developed an EMG-A pattern. There was no difference in the timing of the second EMG (mean, 23 days) between the two groups. The mean CI score (10.7 for EMG-A vs. 9.2 for EMG-D, P = 0.47) and frequency of sepsis (89% vs. 77%, P = 0.36) were similar between the groups. Mean strength (0-100, Medical Research Council scale) and Hughes disability scores for the EMG-A group were significantly worse at admission, nadir, and discharge. EMG-A patients had significantly more days on the ventilator (25 vs. 11), in the ICU (26 vs. 15), and in the hospital (29 vs. 18). Sixty-eight percent of patients with GBS in the ICU developed axon loss, but this was not related to the usual precipitants of CIP.

Peripheral neuropathy

Patients presenting with symptoms of peripheral neuropathy are commonplace in the practice of generalist physicians, office based or hospitalists. Although there are at least a thousand different causes for peripheral neuropathy, the majority of patients can be properly diagnosed (and managed) based on framing the diagnostic possibilities within one of six typical scenarios. The case presentations in this article illustrate common and less common but essential presentations and the approach to evaluation and treatment. For these patients the key to success lies in the history and clinical examination findings.

Acute motor-sensory axonal neuropathy associated with active systemic lupus erythematosus and anticardiolipin antibodies

Acute motor-sensory axonal neuropathy (AMSAN) is an axonal variant of Guillian-Barré syndrome (GBS) that presents with acute ascending quadriparesis. This has generally been described in association with Campylobacter jejuni infections or with anti-ganglioside antibodies. Known cases have shown a slow recovery and a poor prognosis. We report a case with clinical and electrophysiological evidence of AMSAN in association with active systemic lupus erythematosus (SLE) and anticardiolipin antibodies but not the other associations, with a rapid response to combination immunosuppressant and intravenous immunoglobulin (IVIg) therapy. The association between AMSAN and SLE has not been previously described. This case illustrates that early recognition and the utilization of electrophysiologic techniques may be beneficial in the diagnosis and management of GBS associated with SLE. Fulminant or rapidly progressive cases should be managed in specialized intensive care units. Combination therapy of immunosuppressants and IVIg may be beneficial in non-vasculitic axonal radiculo-neuropathies associated with SLE, resulting in good outcomes.

Pain hypersensitivity in rats with experimental autoimmune neuritis, an animal model of human inflammatory demyelinating neuropathy

Experimental autoimmune neuritis (EAN) is a T cell mediated autoimmune disease of the peripheral nervous system that serves as an animal model of the acute inflammatory demyelinating polyradiculoneuropathy in Guillain-Barre syndrome (GBS). Although pain is a common symptom of GBS occurring in 55-85% of cases, it is often overlooked and the underlying mechanisms are poorly understood. Here we examined whether animals with EAN exhibit signs of neuropathic pain including hyperalgesia and allodynia, and assessed their peripheral nerve autoimmune inflammation. We immunized Lewis rats with peripheral myelin P2 peptide (amino acids 57-81) emulsified with complete Freund's adjuvant, or with adjuvant only as control. P2-immunized rats developed mild to modest monophasic EAN with disease onset at day 8, peak at days 15-17, and full recovery by day 28 following immunization. Rats with EAN showed a significant decrease in withdrawal latency to thermal stimuli and withdrawal threshold to mechanical stimuli, in both hindpaws and forepaws, during the course of the disease. We observed a significant infiltration of T cells bearing alphabeta receptors, and a significant increase in antigen-presenting cells expressing MHC class II as well as macrophages, in EAN-affected rats. Our results demonstrate that animals with active EAN develop significant thermal hyperalgesia and mechanical allodynia, accompanied by pronounced autoimmune inflammation in peripheral nerves. These findings suggest that EAN is a useful model for the pain seen in many GBS patients, and may facilitate study of neuroimmune mechanisms underlying pain in autoimmune neuropathies.

Variants and Mimics of Guillain Barré Syndrome

BACKGROUND

The clinical and pathologic spectrum of Guillain Barre Syndrome (GBS) has expanded to include both demyelinating and axon loss forms. GBS may also have atypical presentations. For these reasons, clinicians are more likely to overlook unrelated disorders that mimic GBS.

REVIEW SUMMARY

In this article, the classic presentation and variants of GBS are briefly reviewed. Disorders that mimic GBS are reviewed in detail, including those caused by neurotoxins, heavy metals, chemical toxins, drugs, vasculitis, hereditary disorders, infections, critical illness, and myelopathy. Illustrative case studies accompany a number of the descriptions.

CONCLUSIONS

Failure to recognize the mimics of GBS can lead to erroneous diagnosis, inappropriate treatment, and significant morbidity. Appropriate diagnosis requires a combination of careful history and examination, and accurate interpretation of diagnostic testing.

Prospective study of clinical epidemiology of Guillain–Barré syndrome in Harbin, China

Clinical manifestations, outcomes, prognostic indicators, and clinico-epidemiological subgroups were described based on the information of 71 patients with Guillain-Barré syndrome (GBS), who were identified from a prospective survey in Harbin, China during a 1-year period from 1 October 1997 to 30 September 1998. GBS diagnoses of the patients were validated by senior neurologists and most patients were followed up for 6 months after onset. Antecedent events, mainly respiratory infections, were found in 55 (78%) patients during the month before onset. The clinical features, like motor weakness as initial symptoms (82%) and tendon areflexia or hyporeflexia (100%), are similar to those reported from other populations. However, the proportion (70%) of patients reaching to nadir less than 7 days after onset was rather high. Intravenous human immunoglobulin and/or plasmapheresis were used in 45% of the patients and steroids in 58%. At 6 months after onset, 82% of the patients could walk without aid, 46% of the patients had no any residual signs. Four (6%) patients died within 1 month due to respiratory failure. Three subgroups with different clinico-epidemiological characteristics were identified by using cluster analysis. In conclusion, GBS patients in Harbin, China were younger, had shorter time to nadir, frequently preceded by a respiratory infection, and often treated with steroids. Clinical and epidemiological differences of GBS might exist between various populations.

Guillain-Barré syndrome with marked pleocytosis or a significant proportion of polymorphonuclear granulocytes in the cerebrospinal fluid: neuropathological investigation of five cases and review of differential diagnoses

In cases with otherwise clinically typical Guillain-Barré syndrome (GBS), pronounced cerebrospinal fluid (CSF) pleocytosis or the mere presence of CSF-polymorphonuclear granulocytes should alert the physician to consider alternative diagnoses. Therefore, we retrospectively studied the neuropathology of central and peripheral nervous system in two cases with a CSF cell count of more than 50/microl and in three cases with a significant proportion of polymorphonuclear granulocytes in the CSF sediment. All cases fulfilled the required criteria for the diagnosis of GBS, the duration from onset to death ranged from 4 to 100 days. Neuropathological investigations included routine staining procedures and immunohistochemistry for antigens of glial and haematopoetic cells as well as for products of relevant neurotropic viruses. Demyelinating polyradiculitis was present in four cases, in one patient with a survival time of 4 days the type of damage to myelinated fibres was unclassifiable. In the central nervous system a consistent finding was diffuse activation of microglia, only one case showed mild meningeal and lower brainstem inflammation. Viral products were generally absent. In summary, the neuropathological findings confirm that marked CSF pleocytosis or the presence of polymorphonuclear granulocytes does not rule out the diagnosis of GBS.

Neurophysiological changes in demyelinating and axonal forms of acute experimental autoimmune neuritis in the Lewis rat

Myelin-sensitized T- and B-cells (lymph node cells) induced experimental autoimmune neuritis (EAN) in Lewis rats after passive transfer to naive recipients. After 6 days, all recipient rats developed tail paresis that progressed to limb paresis within 12-72 h. Progressive nerve conduction changes consistent with demyelination in the sciatic nerve (conduction block and prolongation of the distal motor latencies) and lumbar nerve roots (initial low F-wave frequencies followed by later prolongation in F-wave latencies) were observed during the disease. For comparison, adoptive transfer experimental autoimmune neuritis (AT-EAN) of differing disease severity was induced by titrating the dose of P2-specific T-cells. In contrast to EAN induced by myelin-sensitized T- and B-cells, AT-EAN was predominantly associated with rapid nerve conduction changes consistent with axonal dysfunction and degeneration. These findings demonstrate that distinct forms of EAN with different pathophysiological mechanisms are induced by the passive transfer of P2-specific T-cell lines or myelin-specific T-cells and B-cells. The electrophysiological changes in EAN induced by myelin-specific T- and B-cells are very similar to those seen clinically during acute inflammatory demyelinating polyneuropathy, whereas AT-EAN has less resemblance to axonal forms of Guillain-Barré syndrome.

Nerve conduction studies in selected peripheral nerve disorders

PURPOSE OF REVIEW

The physiological properties of nerve and muscle are influenced by pathological changes and the aim of this review is to discuss recent contributions of electrophysiological studies to the understanding and diagnosis of selected peripheral nerve disorders. The relationships between pathology and physiology emphasize the close interdependence between electrophysiological studies, clinical deficits and other laboratory information. Attention should be paid to the strengths and limitations of electrophysiological methods, considering their impact on diagnosis and treatment of patients.

RECENT FINDINGS

Several studies have shown particular pathophysiological profiles associated with different antibody subtypes in autoimmune peripheral neuropathies and this association further supports the suggestion of pathological specificity in both acute and chronic neuropathy. The sensitivity and specificity of physiological profiles therefore become increasingly important since some of these neuropathies are accessible to treatment. On the other hand, the pathophysiological and clinical profiles may be heterogeneous in patients with some disorders. This could be related to a more indistinct division between different types of pathology with increased understanding of pathogenetic mechanisms. Moreover, new insights into disturbed axonal function have stimulated attempts to develop methods to explore normal and diseased human nerve function.

SUMMARY

The exploration of axonal membrane and ion-channel function has become accessible using studies of excitability and are of potential value where conventional studies only provide nonspecific evidence of the number of fibers and the integrity of myelin. These studies will presumably become increasingly important in the years ahead considering the lack of understanding of the functional disturbances in axonal neuropathies.