Fulminant Guillain-Barré syndrome with universal inexcitability of peripheral nerves: a clinicopathological study

The pathophysiological role of endoneurial inflammatory edema in early classical Guillain-Barré syndrome

The objective of this review was to analyze the pathophysiological role of endoneurial inflammatory edema in initial stages of classic Guillain-Barré syndrome (GBS), arbitrarily divided into very early GBS (≤ 4 days after symptom onset) and early GBS (≤ 10 days). Classic GBS, with variable degree of flaccid and areflexic tetraparesis, encompasses demyelinating and axonal forms. Initial autopsy studies in early GBS have demonstrated that endoneurial inflammatory edema of proximal nerve trunks, particularly spinal nerves, is the outstanding lesion. Variable permeability of the blood-nerve barrier dictates such lesion topography. In proximal nerve trunks possessing epi-perineurium, edema may increase the endoneurial fluid pressure causing ischemic changes. Critical analysis the first pathological description of the axonal form GBS shows a combination of axonal degeneration and demyelination in spinal roots, and pure Wallerian-like degeneration in peripheral nerve trunks. This case might be reclassified as demyelinating GBS with secondary axonal degeneration. Both in acute motor axonal neuropathy and acute motor-sensory axonal neuropathy, Wallerian-like degeneration of motor fibers predominates in the distal part of ventral spinal roots abutting the dura mater, another feature re-emphasizing the pathogenic relevance of this area. Electrophysiological and imaging studies also point to a predominant alteration at the spinal nerve level, which is a hotspot in any early GBS subtype. Serum biomarkers of axonal damage, including neurofilament light chain and peripherin, are increased in the great majority of patients with any early GBS subtype; endoneurial ischemia of proximal nerve trunks could contribute to such axonal damage. It is concluded that inflammatory edema of proximal nerve trunks is an essential pathogenic event in early GBS, which has a tangible impact for accurate approach to the disease.

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.

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.

Campylobacter jejuni Infection, Anti-Ganglioside Antibodies, and Neuropathy

Preceding infection with Campylobacter jejuni (Cj) occurs in approximately 30% of patients with Guillain–Barre syndrome (GBS), and the risk of GBS following Cj infection is increased by 77 to 100-fold. GBS is most often of the axonal subtype and is thought to be mediated by IgG antibodies to peripheral nerve gangliosides that are cross reactive with oligosaccharides in the Cj lipopolysaccharides (LPS). The antibodies are thought to be induced by molecular mimicry, where immune reactivity to a cross reactive epitope in the infectious organism and normal tissue can cause autoimmune disease. Clonally restricted IgM antibodies that react with the same oligosaccharides in gangliosides and Cj-LPS are associated with chronic neuropathies of otherwise similar phenotypes. The anti-ganglioside antibodies in GBS are of the IgG1 and IgG3 subclasses, indicating T-cell reactivity to the same antigens that could help disrupt the blood–nerve barrier. Cj infection can activate multiple innate and adoptive pro-inflammatory pathways that can overcome immune tolerance and induce autoimmunity. Elucidation of the specific immune mechanisms involved in the development of the autoantibodies and neuropathy would help our understanding of the relation between infection and autoimmunity and aid in the development of more effective preventive interventions and therapies.

Axonal pathology in early stages of Guillain-Barré syndrome

INTRODUCTION

Guillain-Barré syndrome (GBS) is an acute-onset, immune-mediated disease of the peripheral nervous system. It may be classified into 2 main subtypes: demyelinating (AIDP) and axonal (AMAN). This study aims to analyse the mechanisms of axonal damage in the early stages of GBS (within 10 days of onset).

DEVELOPMENT

We analysed histological, electrophysiological, and imaging findings from patients with AIDP and AMAN, and compared them to those of an animal model of myelin P2 protein-induced experimental allergic neuritis. Inflammatory oedema of the spinal nerve roots and spinal nerves is the initial lesion in GBS. The spinal nerves of patients with fatal AIDP may show ischaemic lesions in the endoneurium, which suggests that endoneurial inflammation may increase endoneurial fluid pressure, reducing transperineurial blood flow, potentially leading to conduction failure and eventually to axonal degeneration. In patients with AMAN associated with anti-ganglioside antibodies, nerve conduction block secondary to nodal sodium channel dysfunction may affect the proximal, intermediate, and distal nerve trunks. In addition to the mechanisms involved in AIDP, active axonal degeneration in AMAN may be associated with nodal axolemma disruption caused by anti-ganglioside antibodies.

CONCLUSION

Inflammatory oedema of the proximal nerve trunks can be observed in early stages of GBS, and it may cause nerve conduction failure and active axonal degeneration.

Axonal pathology in early stages of Guillain-Barré syndrome

INTRODUCTION

Guillain-Barré syndrome (GBS) is an acute-onset, immune-mediated disease of the peripheral nervous system. It may be classified into 2 main subtypes: demyelinating (AIDP) and axonal (AMAN). This study aims to analyse the mechanisms of axonal damage in the early stages of GBS (within 10days of onset).

DEVELOPMENT

We analysed histological, electrophysiological, and imaging findings from patients with AIDP and AMAN, and compared them to those of an animal model of myelin P2 protein-induced experimental allergic neuritis. Inflammatory oedema of the spinal nerve roots and spinal nerves is the initial lesion in GBS. The spinal nerves of patients with fatal AIDP may show ischaemic lesions in the endoneurium, which suggests that endoneurial inflammation may increase endoneurial fluid pressure, reducing transperineurial blood flow, potentially leading to conduction failure and eventually to axonal degeneration. In patients with AMAN associated with anti-ganglioside antibodies, nerve conduction block secondary to nodal sodium channel dysfunction may affect the proximal, intermediate, and distal nerve trunks. In addition to the mechanisms involved in AIDP, active axonal degeneration in AMAN may be associated with nodal axolemma disruption caused by anti-ganglioside antibodies.

CONCLUSION

Inflammatory oedema of the proximal nerve trunks can be observed in early stages of GBS, and it may cause nerve conduction failure and active axonal degeneration.

Sensory root demyelination: Transforming touch into pain

The normal feeling of touch is vital for nearly every aspect of our daily life. However, touching is not always felt as touch, but also abnormally as pain under numerous diseased conditions. For either mechanistic understanding of the faithful feeling of touch or clinical management of chronic pain, there is an essential need to thoroughly dissect the neuropathological changes that lead to painful touch or tactile allodynia and their corresponding cellular and molecular underpinnings. In recent years, we have seen remarkable progress in our understanding of the neural circuits for painful touch, with an increasing emphasis on the upstream roles of non-neuronal cells. As a highly specialized form of axon ensheathment by glial cells in jawed vertebrates, myelin sheaths not only mediate their outstanding neural functions via saltatory impulse propagation of temporal and spatial precision, but also support long-term neuronal/axonal integrity via metabolic and neurotrophic coupling. Therefore, myelinopathies have been implicated in diverse neuropsychiatric diseases, which are traditionally recognized as a result of the dysfunctions of neural circuits. However, whether myelinopathies can transform touch into pain remains a long-standing question. By summarizing and reframing the fragmentary but accumulating evidence so far, the present review indicates that sensory root demyelination represents a hitherto underappreciated neuropathological change for most neuropathic conditions of painful touch and offers an insightful window into faithful tactile sensation as well as a potential therapeutic target for intractable painful touch.

Guillain-Barré Syndrome-Like Polyneuropathy Associated with Immune Checkpoint Inhibitors: A Systematic Review of 33 Cases

Immune checkpoint inhibitors (ICIs) have been increasingly used in the treatment of various types of tumors with favorable results. But these treatments also led to a variety of immune-related adverse events (irAEs). Neurological irAEs such as Guillain-Barré Syndrome are rare and may have serious consequences once they occur. A systematic literature search was performed in PubMed and Embase for all case reports of GBS associated with ICIs published in English reporting on human beings from 1990 up to date. A total of 30 case reports (total patients = 33) were used for final analysis. The included cases were from 11 countries, covering 10 tumor types, with melanoma accounting for the largest number. The mean age was 62.2 ± 11.1 years old, and males were dominant (male: 26 and female: 7). The median time of initial symptoms was 8.2 weeks after the 1^st dose of ICIs. The most common manifestations of GBS associated with ICIs were weakness, hyporeflexia or areflexia, and paresthesia in order. The GBS subtypes suggested by electrophysiological results were acute inflammatory demyelinating polyneuropathy (AIDP), acute motor axonal neuropathy (AMAN), and Miller Fisher syndrome (MFS). The protein level of CSF in patients with GBS related to ICIs was 180.68 ± 152.51 mg/dl. Immediate termination of ICIs followed by intravenous immunoglobulin was the preferred treatment option. 72.7% of patients recovered or had residual mild dysfunction after treatment. Elderly male patients with melanoma were most likely to develop ICI-related GBS. The specific neurological symptoms, CSF analysis, and electrophysiological examination were important means of diagnosis.

Macrophages and Autoantibodies in Demyelinating Diseases

Myelin phagocytosis by macrophages has been an essential feature of demyelinating diseases in the central and peripheral nervous systems, including Guillain–Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathy (CIDP), and multiple sclerosis (MS). The discovery of autoantibodies, including anti-ganglioside GM1 antibodies in the axonal form of GBS, anti-neurofascin 155 and anti-contactin 1 antibodies in typical and distal forms of CIDP, and anti-aquaporin 4 antibodies in neuromyelitis optica, contributed to the understanding of the disease process in a subpopulation of patients conventionally diagnosed with demyelinating diseases. However, patients with these antibodies are now considered to have independent disease entities, including acute motor axonal neuropathy, nodopathy or paranodopathy, and neuromyelitis optica spectrum disorder, because primary lesions in these diseases are distinct from those in conventional demyelinating diseases. Therefore, the mechanisms underlying demyelination caused by macrophages remain unclear. Electron microscopy studies revealed that macrophages destroy myelin as if they are the principal players in the demyelination process. Recent studies suggest that macrophages seem to select specific sites of myelinated fibers, including the nodes of Ranvier, paranodes, and internodes, for the initiation of demyelination in individual cases, indicating that specific components localized to these sites play an important role in the behavior of macrophages that initiate myelin phagocytosis. Along with the search for autoantibodies, the ultrastructural characterization of myelin phagocytosis by macrophages is a crucial step in understanding the pathophysiology of demyelinating diseases and for the future development of targeted therapies.

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.

Polyneuropathy in Young Siberian Huskies Caused by Degenerative and Inflammatory Diseases

Polyneuropathy is defined as the simultaneous dysfunction of several peripheral nerves. In dogs, a number of breeds are predisposed to a variety of immune-mediated and/or degenerative inherited forms of polyneuropathy, with laryngeal paralysis and/or megaesophagus as important clinical features of many of these conditions. This case series describes degenerative and inflammatory polyneuropathies in 7 young Siberian huskies that were categorized based on clinicopathological characteristics as follows: (1) slowly progressive laryngeal paralysis and megaesophagus caused by primary axonal degeneration with large fiber loss (n = 2); (2) slowly progressive polyneuropathy without megaesophagus or laryngeal paralysis caused by primary axonal degeneration with large fiber loss (n = 2); (3) acute inflammatory demyelinating neuropathy causing sensory, motor and autonomic nerve deficits (n = 2); and (4) ganglioradiculitis (sensory neuronopathy; n = 1). Based on the predominantly young age at onset, slow progression, relatedness of affected dogs, and clinical and pathological similarities with inherited neuropathies reported in other dog breeds, a hereditary basis for the degenerative polyneuropathies in Siberian huskies is suspected. However, 5 different mutations in 3 genes known to cause polyneuropathy in other dog breeds (NDRG1, ARHGEF10, or RAB3GAP1) were not detected in the affected Siberian huskies suggesting that more genetic variants remain to be identified. This study highlights the varied underlying lesions of polyneuropathies in young Siberian huskies.

Ultrastructural mechanisms of macrophage-induced demyelination in Guillain-Barré syndrome

OBJECTIVE

To describe the pathological features of Guillain-Barré syndrome focusing on macrophage-associated myelin lesions.

METHODS

Longitudinal sections of sural nerve biopsy specimens from 11 patients with acute inflammatory demyelinating polyneuropathy (AIDP) exhibiting macrophage-associated demyelinating lesions were examined using electron microscopy. A total of 1205 nodes of Ranvier were examined to determine the relationship of the macrophage-associated demyelinating lesions with the nodal regions. Additionally, immunohistochemical and immunofluorescent studies were performed to elucidate the sites of complement deposition.

RESULTS

Overall, 252 macrophage-associated myelin lesions were identified in longitudinal sections. Of these, 40 lesions exhibited complete demyelination with no association with the lamellar structures of myelin. In 183 lesions, macrophage cytoplasm was located at internodes without association with the nodes of Ranvier or paranodes. In particular, these internodal lesions were more frequent in one patient (152 lesions). In the remaining 29 lesions, the involvement of nodal regions was obvious. Lesions involving nodal regions were more frequently observed than those involving internodes in four patients. Invasion of the macrophage cytoplasmic processes into the space between the paranodal myelin terminal loops and the axolemma from the nodes of Ranvier was observed in three of these patients. Immunostaining suggested complement deposition corresponding to putative initial macrophage-associated demyelinating lesions.

CONCLUSIONS

The initial macrophage-associated demyelinating lesions appeared to be located at internodes and at nodal regions. The sites at which the macrophages initiated phagocytosis of myelin might be associated with the location of complement deposition in certain patients with AIDP.

Early predictors of functional disability in Guillain-Barré Syndrome

This study investigated the predictors of prognosis at admission and after the first month in Guillain-Barré syndrome (GBS) patients. This retrospective study used the electronic records of 81 GBS patients. Age, gender, previous GBS history, antecedent febrile illness and presence of cranial nerve dysfunction were recorded. Detailed neurological examinations, routine biochemical and haematological investigations, cerebrospinal fluid (CSF) analysis and electrophysiological studies, GBS subtypes and treatments were assessed. Hughes disability scores (HDSs) were evaluated at the end of the first day and first month. The GBS patient group included 44 male (54.3%) and 37 female (45.7%) patients. The mean age was 52.2 ± 18.5. The mean HDS score was 2.96 at admission and 1.94 at the end of the first month. Plasma sodium, albumin, and CSF protein levels were significantly correlated with low admission HDS scores (p = 0.03, p  = 0.011, p  = 0.036, and p  < 0.001, respectively). Age, plasma sodium, albumin, neutrophil, neutrophil/lymphocyte ratio (NLR) levels, C-reactive protein (CRP) and CSF protein levels were significantly correlated with poor prognosis at the end of the first month (p < 0.05). Concomitant cranial nerve palsies were significantly correlated with low HDS scores (p = 0.011, p = 0.02) but antecedent events were not correlated with functional disability (p = 0.686, p = 0.413). Decreased albumin and sodium levels and increased CSF protein levels indicated poor GBS prognosis. Higher age, elevated NLR, and higher CRP levels indicated worse prognosis at the end of the first month. However, further studies are needed.

Guillain-Barré syndrome with exaggerated pleocytosis and anti-GM1 ganglioside antibodies

An 81-year-old man presented with fever, confusion and rapidly-progressive flaccid tetraparesis. Clinical presentation and neurophysiology were consistent with a severe axonal polyneuropathy. Anti-GM1 and Campylobacter serology were both positive, consistent with postinfectious axonal-variant Guillain-Barré syndrome (GBS). GBS is characterised by albuminocytological dissociation, where an elevated protein and acellular cerebrospinal fluid are typical. However, in this case, CSF analysis revealed an exaggerated pleocytosis (72 white blood cells (WBC)/mm³). No source of central nervous system infection or inflammation was identified despite thorough investigation. The patient was treated with intravenous immunoglobulin and intensive rehabilitation.Albuminocytological dissociation classically distinguishes GBS from infective causes of flaccid weakness (eg, enteroviruses, flaviviruses and HIV). Diagnostic criteria frequently cite a pleocytosis of <50 WBC/mm³ as required in the diagnosis of GBS. However, this case demonstrates that pleocytosis exceeding this level can occur in the presence of convincing evidence of GBS and without demonstrable neurotropic infection.

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.

Predictive factors for achieving independent walking in children with Guillain-Barre syndrome

BackgroundTo determine the predictors of achieving independent walking at 2 and 6 months after onset of weakness in children with Guillain-Barre syndrome (GBS).MethodsChildren with GBS admitted to the Tabriz Children's Hospital were studied prospectively. All patients had frequent clinical evaluations until achieving independent walking. Unaided walking at 2 and 6 months and factors influencing these outcomes were determined using both univariate and multiple analyses.ResultsBetween 2003 and 2014, 324 children (mean age: 5.3±3.66 years) were admitted. The mean duration to independent walking was 2.97±3.02 months; 90.5% of patients could walk independently at 6 months. In the univariate analysis, disability score of >3 (P=0.03), autonomic nerve involvement (P=0.003), cranial nerve involvement (P=0.008), and absent compound muscle action potential (CMAP; P=0.048) were found to be significantly associated with poor walking outcome at 6 months. In the multivariate analysis, cranial nerve involvement (P=0.008) and absence of CMAP (P=0.022) were independently associated with poor functional outcome.ConclusionDisability score >3, cranial and autonomic nerve involvement, and absence of CMAP were predictors of independent walking in childhood GBS in this study; early rehabilitation program may prevent further impairments secondary to immobility in these patients.

Long-term impact after fulminant Guillain-Barré syndrome, case report and literature review

A 47-year-old man was admitted to the intensive care unit a few hours after presenting to emergency department with acute diplopia and dysphonia. Swallowing disorders and respiratory muscular weakness quickly required invasive ventilation. On day 3, the patient was in a “brain-death”-like state with deep coma and absent brainstem reflexes. Electroencephalogram ruled out brain death diagnosis as a paradoxical sleep trace was recorded. Cerebrospinal fluid analysis, electrophysiologic studies, and a recent history of diarrhea led to the diagnosis of Campylobacter jejuni-related fulminant Guillain-Barré syndrome (GBS) mimicking brain death. The outcome was favorable after long Intensive Care Unit and inpatient rehabilitation stays, despite persistent disability at 9 years follow-up. This case and the associated literature review of 34 previously reported fulminant GBS patients emphasize the importance of electrophysiological investigations during clinical brain-death states with no definite cause. Fulminant GBS has a worse outcome than “standard” GBS with higher rates of severe disability (about 50%). Long-term physiotherapy and specific rehabilitation programs appear essential to improve recovery.

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.

Miller-Fisher syndrome associated with unilateral cerebral white matter lesions

Miller-Fisher syndrome (MFS) is characterized by classical triad of ophthalmoplegia, ataxia and areflexia. The involvement of cerebral white matter in MFS is very rare. We report a typical MFS patient whose brain MRI showed unilateral and extensive involvement in cerebral white matter. We also found mild pleocytosis and raised protein concentration in cerebrospinal fluid. Deficits resolved completely after treatment with intravenous immunoglobulins. Subsequent brain MRI shows cavity formation in involved white matter.

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.

Spinal nerve involvement in early Guillain-Barré syndrome: a clinico-electrophysiological, ultrasonographic and pathological study

OBJECTIVE

Although prevailing spinal nerve involvement has been recognized in a few detailed Guillain-Barré syndrome (GBS) autopsy reports, imaging studies addressing this question in cervical nerves are lacking.

METHODS

We describe clinical, electrophysiological, ultrasonographic (US) and pathological findings in six consecutive early GBS patients, evaluated within 10 days of onset.

RESULTS

Patients' ages ranged from 37 to 80 years. Five patients required mechanical ventilation, two of them having died 9 and 28 days after onset. Upper- and lower-limb nerve US showed abnormal findings in just 8.8% of scanned peripheral nerves. In comparison with 46 aged-matched control subjects, US of the fifth to seventh cervical nerves showed changes in four cases, which consisted of significant nerve enlargement, blurred boundaries of the corresponding ventral rami, or both. Autopsy study in one case demonstrated that pathology, consisting of demyelination and endoneurial inflammatory oedema, mainly involved cervical and lumbar nerves.

CONCLUSIONS

In early GBS inflammatory oedema of spinal nerves is a pathogenically relevant feature to understanding the mechanism of ascending paralysis, particularly when conventional electrophysiological studies are normal or not diagnostic.

SIGNIFICANCE

Findings advocate the use of cervical nerve US in early GBS.

Muscle MRI in severe Guillain-Barré syndrome with motor nerve inexcitability

We report on the clinical, electrophysiological, and lower-limb musculature MRI findings in a severe demyelinating Guillain-Barré syndrome (GBS) patient with follow-up over 6 months. After 3 weeks of tetraplegia and mechanical ventilation, there was progressive improvement until almost complete recovery. On day 4 after onset, electrophysiological study revealed absent F waves and widespread conduction block. On four further electrophysiological studies on days 12, 19, 45, and 150, there was marked and reversible slow down of motor conduction velocities in upper-limb nerves, and persistent inexcitability of lower-limb nerves. Mild signs of active denervation were recorded in calf and foot muscles as of day 45. On day 39, MRI T2-weighted fat-suppressed images showed patchy hypersignal of variable intensity involving pelvic, thigh, and calf muscles, which disappeared in a second imaging study on day 190; in this study T1-weighted images did not disclose muscle fatty atrophy. We conclude that in severe demyelinating GBS prolonged motor nerve inexcitability should not necessarily be taken as a predictor of poor prognosis, and that MRI is useful in assessing the topography and evolution of muscle denervation.

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.

α(M)β(2)-integrin-intercellular adhesion molecule-1 interactions drive the flow-dependent trafficking of Guillain-Barré syndrome patient derived mononuclear leukocytes at the blood-nerve barrier in vitro

The mechanisms of hematogenous leukocyte trafficking at the human blood-nerve barrier (BNB) are largely unknown. Intercellular adhesion molecule-1 (ICAM-1) has been implicated in the pathogenesis of Guillain-Barré syndrome (GBS). We developed a cytokine-activated human in vitro BNB model using primary endoneurial endothelial cells. Endothelial treatment with 10 U/ml tissue necrosis factor-α and 20 U/ml interferon-γ resulted in de novo expression of pro-inflammatory chemokines CCL2, CXCL9, CXCL11, and CCL20, with increased expression of CXCL2-3, CXCL8, and CXCL10 relative to basal levels. Cytokine treatment induced/enhanced ICAM-1, E- and P-selectin, vascular cell adhesion molecule-1 and the alternatively spliced pro-adhesive fibronectin variant, fibronectin connecting segment-1 expression in a time-dependent manner, without alterations in junctional adhesion molecule-A expression. Lymphocytes and monocytes from untreated GBS patients express ICAM-1 counterligands, α(M)- and α(L)-integrin, with differential regulation of α(M) -integrin expression compared to healthy controls. Under flow conditions that mimic capillary hemodynamics in vivo, there was a >3-fold increase in total GBS patient and healthy control mononuclear leukocyte adhesion/migration at the BNB following cytokine treatment relative to the untreated state. Function neutralizing monoclonal antibodies against human α(M)-integrin (CD11b) and ICAM-1 reduced untreated GBS patient mononuclear leukocyte trafficking at the BNB by 59% and 64.2%, respectively. Monoclonal antibodies against α(L)-integrin (CD11a) and human intravenous immunoglobulin reduced total leukocyte adhesion/migration by 22.8% and 17.6%, respectively. This study demonstrates differential regulation of α(M)-integrin on circulating mononuclear cells in GBS, as well as an important role for α(M)-integrin-ICAM-1 interactions in pathogenic GBS patient leukocyte trafficking at the human BNB in vitro.

Fulminant inflammatory neuropathy mimicking cerebral death

We report a case of a 44-year-old woman who developed rapidly progressive tetraparesis followed by respiratory failure and abolition of brainstem reflexes. Electrodiagnostic studies excluded the possibility of cerebral death and confirmed the diagnosis of acute motor-sensory axonal neuropathy. The initial fulminant course of the disease was followed by slow recovery to independence in daily activities.

Outcome in childhood Guillain-Barré syndrome

OBJECTIVE

To prospectively assess the outcome of children diagnosed with Guillain-Barré syndrome (GBS), followed up for a median duration of 25 months.

METHODS

Tertiary center, prospective follow up of children with GBS enrolled between, Dec 2003 to Sep 2006. Functional recovery was determined at 12 months and later using Hughes scale (0-6). Clinical, electrophysiological variables were compared between the good outcome (grade 0/1) and bad outcome groups (died or functional grade >1).

RESULTS

Among 52 children with a median age of five yr there was male preponderance (75.4%). Mortality during acute phase was 11.5% (6/52). Among the survivors long term data was obtainable in 40 of the 46 children. At one year follow up 87.5% children had fully recovered or had minimal symptoms, beyond one year this rose to 95%. Only 2 among 40 had significant symptoms at last follow up (1 grade-2 and 1 grade-3). Factors significantly associated with poor outcome were: need for artificial ventilation, inexitable nerves on nerve conduction testing and delayed independent walking.

CONCLUSION

Children needing ventilation have the worst short-term prognosis. However, irrespective of severity during acute phase, good long-term recovery can be expected in most children.

Fulminant Guillain–Barré syndrome after closed head injury: a potentially reversible cause of an ominous examination

✓ Fulminant Guillain–Barré syndrome (GBS) is a rapidly progressive form of polyneuropathy in which patients demonstrate eventual flaccid quadriplegia and an absence of brainstem function. Most patients present after a mild upper respiratory or gastrointestinal illness and have nondiagnostic cerebral imaging studies. The authors present a case of fulminant GBS that developed in a 55-year-old alcoholic man 1 week after admission for a closed head injury. The details of this case and a discussion of GBS will be presented. This case provides evidence for combined central and peripheral nervous system involvement in severe cases of GBS. Recognition of fulminant GBS is important to prevent inappropriate declaration of brain death or withdrawal of support in the face of a potentially reversible process.

Macrophage migration inhibitory factor (MIF) seems crucially involved in Guillain-Barré syndrome and experimental allergic neuritis

Macrophage migration inhibitory factor (MIF) is a proinflammatory type 1 cytokine that plays a pathogenic role in several inflammatory and autoimmune diseases. The role of this cytokine in peripheral nerve inflammatory disease has not been evaluated. Therefore, to evaluate the role of macrophage migration inhibitory factor (MIF) in Guillain-Barré syndrome (GBS) and experimental allergic neuritis (EAN), we determined MIF circulating levels in a series of patients with GBS and healthy subjects with ELISA and evaluated the effect of two specific inhibitors of MIF, a neutralizing monoclonal antibody or a chemical inhibitor ISO1 on the course of murine EAN. The data show increased MIF plasma levels in GBS patients as compared to healthy controls (p<0.0001) and a progressive increase of MIF circulating concentration with patient's disability (p<0.0001). Both anti-MIF mAb and ISO1 favorably influenced the course of EAN. Treated mice had a lower cumulative severity score (p=0.001) and reduced disease duration than the control mice (p<0.03). MIF may promote immune reaction in GBS. Therapeutic effects of both anti-MIF mAb and ISO1 in EAN suggest that MIF could be a promising therapeutic target in inflammatory demyelinating peripheral nerve disorders.

Guillain-Barré syndrome

Guillain-Barré syndrome consists of at least four subtypes of acute peripheral neuropathy. Major advances have been made in understanding the mechanisms of some of the subtypes. The histological appearance of the acute inflammatory demyelinating polyradiculoneuropathy (AIDP) subtype resembles experimental autoimmune neuritis, which is predominantly caused by T cells directed against peptides from the myelin proteins P0, P2, and PMP22. The role of T-cell-mediated immunity in AIDP remains unclear and there is evidence for the involvement of antibodies and complement. Strong evidence now exists that axonal subtypes of Guillain-Barré syndrome, acute motor axonal neuropathy (AMAN), and acute motor and sensory axonal neuropathy (AMSAN), are caused by antibodies to gangliosides on the axolemma that target macrophages to invade the axon at the node of Ranvier. About a quarter of patients with Guillain-Barré syndrome have had a recent Campylobacter jejuni infection, and axonal forms of the disease are especially common in these people. The lipo-oligosaccharide from the C jejuni bacterial wall contains ganglioside-like structures and its injection into rabbits induces a neuropathy that resembles acute motor axonal neuropathy. Antibodies to GM1, GM1b, GD1a, and GalNac-GD1a are in particular implicated in acute motor axonal neuropathy and, with the exception of GalNacGD1a, in acute motor and sensory axonal neuropathy. The Fisher's syndrome subtype is especially associated with antibodies to GQ1b, and similar cross-reactivity with ganglioside structures in the wall of C jejuni has been discovered. Anti-GQ1b antibodies have been shown to damage the motor nerve terminal in vitro by a complement-mediated mechanism. Results of international randomised trials have shown equivalent efficacy of both plasma exchange and intravenous immunoglobulin, but not corticosteroids, in hastening recovery from Guillain-Barré syndrome. Further research is needed to discover treatments to prevent 20% of patients from being left with persistent and significant disability.

Disorder resembling Guillain-Barré syndrome on initiation of statin therapy

We report a disorder resembling Guillain-Barre syndrome, occurring on initiation of simvastatin, in a 58-year-old man, who had experienced a similar but milder episode after starting pravastatin 6 months earlier. This case suggests that acute polyradiculoneuropathy may represent a rare but serious side-effect of statin treatment. It also raises the issue of the pathophysiology of acute neuropathy on statin exposure, with a hypersensitivity reaction resulting in an immune-mediated process being possible instead of the hypothesized mitochondrial dysfunction in chronic cases.

PML bodies in reactive sensory ganglion neurons of the Guillain–Barré syndrome

Acute inflammatory demyelinating polyneuropathy (AIDP) is a type of Guillain-Barré syndrome (GBS) characterized by primary nerve demyelination sometimes with secondary axonal degeneration. Studies on the fine structure of dorsal root ganglia in AIDP are lacking. Our aim was to investigate the cytology and nuclear organization of primary sensory neurons in AIDP with axonal injury using ultrastructural and immunohistochemical analysis. The light cytology of the L5 dorsal ganglion showed the characteristic findings of neuronal axonal reaction. The organization of chromatin, nucleolus, Cajal bodies, and nuclear pores corresponded to transcriptionally active neurons. However, the hallmark of the nuclear response to axonal injury was the formation of numerous nuclear bodies (NBs; 6.37 +/- 0.6, in the AIDP, vs. 2.53 +/- 0.2, in the control, mean +/- SDM), identified as promyelocytic leukemia (PML) bodies by the presence of the protein PML. In addition to PML protein, nuclear bodies contained SUMO-1 and the transcriptional regulators CREB-binding protein (CBP) and glucocorticoid receptor (GR). The presence of proteasome 19S was also detected in some nuclear bodies. We suggest that neuronal PML bodies could regulate the nuclear concentration of active proteins, a process mediated by protein interactions with PML and SUMO-1 proteins. In the AIDP case, the proliferation of PML bodies may result from the overexpression of some nuclear proteins due to changes in gene expression associated with axonal injury.

Effect of methylprednisolone when added to standard treatment with intravenous immunoglobulin for Guillain-Barré syndrome: randomised trial

BACKGROUND

Despite available treatment with intravenous immunoglobulin (IVIg), morbidity and mortality are considerable in patients with Guillain-Barré syndrome (GBS). Our aim was to assess whether methylprednisolone, when taken with IVIg, improves outcome when compared with IVIg alone.

METHODS

We did a double-blind, placebo-controlled, multicentre, randomised study, to which we enrolled patients who were unable to walk independently and who had been treated within 14 days after onset of weakness with IVIg (0.4 g/kg bodyweight per day) for 5 days. We assigned 233 individuals to receive either intravenous methylprednisolone (500 mg per day; n=116) or placebo (n=117) for 5 days within 48 h of administration of first dose of IVIg. Because age is an important prognostic factor, we split treatment groups into two age-groups-ie, younger than age 50 years, or 50 years and older. Our primary outcome was an improvement from baseline in GBS disability score of one or more grades 4 weeks after randomisation. Analysis was by intention to treat.

FINDINGS

We analysed 225 patients. GBS disability scores increased by one grade or more in 68% (76 of 112) of patients in the methylprednisolone group and in 56% (63 of 113) of controls (odds ratio [OR] 1.68, 95% CI 0.97-2.88; p=0.06). After adjustment for age and degree of disability at entry, treatment OR was 1.89 (95% CI 1.07-3.35; p=0.03). Side-effects did not differ greatly between groups.

INTERPRETATION

We noted no significant difference between treatment with methylprednisolone and IVIg and IVIg alone. Because of the relevance of prognostic factors and the limited side-effects of methylprednisolone, the potential importance of combination treatment with the drug and IVIg, however, warrants further investigation.

Clinical deterioration in Bickerstaff's brainstem encephalitis caused by overlapping Guillain-Barré syndrome

A 37-year-old man developed an acute encephalitic condition after respiratory infection. His condition rapidly deteriorated, and he experienced ophthalmoplegia, tetraplegia, loss of brainstem reflexes and deep tendon reflexes, and deep coma. Electrophysiological evaluations indicated involvement of the peripheral nerve as well as the brainstem. Follow-up studies found acute progression of peripheral nerve damage. Serum anti-GQ1b IgG antibody was present. The initial condition was diagnosed as Bickerstaff's brainstem encephalitis, and subsequent overlapping of Guillain-Barré syndrome probably was responsible for the clinical deterioration. When unusual worsening is observed in clinically suspected encephalitis, neurologists must take into account the possibility of associated Guillain-Barré syndrome and related disorders.

Monocyte chemoattractant protein 1 and chemokine receptor CCR2 productions in Guillain-Barré syndrome and experimental autoimmune neuritis

Infiltration of activated lymphocytes and monocytes is a key phenomenon in the pathogenesis of Guillain-Barré syndrome (GBS) and experimental autoimmune neuritis (EAN). To investigate the role of chemokines, we determined the blood and nerve tissue expression of monocyte chemoattractant protein 1 (MCP-1), a major chemoattractant of monocytes and activated lymphocytes, and its receptor CCR2 in GBS and EAN. MCP-1 circulating levels (ng/ml) in GBS were increased at the time of progression, peaked at the time of plateau and normalized with recovery. MCP-1 circulating levels were the highest in the most disabled patients. The number of circulating CCR2 positive cells was lower in patients with GBS than in healthy subjects (p<0.004). In GBS, MCP-1 expression was observed in epineurial and endoneurial vessels, on infiltrating cells, Schwann cells and in the endoneurial extracellular matrix. Some CCR2 positive cells were observed in nerve biopsies of GBS patients. In EAN, a slight positivity for MCP-1 was observed in the sciatic nerve. There was no circulating CCR2 positive cells. However, at the time of plateau, a conspicuous infiltration of CCR2 positive cells was observed in the sciatic nerve that was no longer observed at the time of recovery. These results suggest that MCP-1 and CCR2 may participate to the recruitment of circulating mononuclear cells in nerve tissue in EAN and GBS.

The role of macrophages in immune-mediated damage to the peripheral nervous system

Macrophage-mediated segmental demyelination is the pathological hallmark of autoimmune demyelinating polyneuropathies, including the demyelinating form of Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy. Macrophages serve a multitude of functions throughout the entire pathogenetic process of autoimmune neuropathy. Resident endoneurial macrophages are likely to act as local antigen-presenting cells by their capability to express major histocompatibility complex antigens and costimulatory B7-molecules, and may thus be critical in triggering the autoimmune process. Hematogenous infiltrating macrophages then find their way into the peripheral nerve together with T-cells by the concerted action of adhesion molecules, matrix metalloproteases and chemotactic signals. Within the nerve, macrophages regulate inflammation by secreting several pro-inflammatory cytokines including IL-1, IL-6, IL-12 and TNF-alpha. Autoantibodies are likely to guide macrophages towards their myelin or primarily axonal targets, which then attack in a complement-dependent and receptor-mediated manner. In addition, non-specific tissue damage occurs through the secretion of toxic mediators and cytokines. Later, macrophages contribute to the termination of inflammation by promoting T-cell apoptosis and expressing anti-inflammatory cytokines including TGF-beta1 and IL-10. During recovery, they are tightly involved in allowing Schwann cell proliferation, remyelination and axonal regeneration to proceed. Macrophages, thus, play dual roles in autoimmune neuropathy, being detrimental in attacking nervous tissue but also salutary, when aiding in the termination of the inflammatory process and the promotion of recovery.

Inhibition of the adhesion step of leukodiapedesis: a critical event in the recovery of Guillain-Barré syndrome associated with accumulation of proteolytically active lymphocytes in blood

Intraneural inflammation, that reflects emigration of immune cells from blood to nerve tissue, is a critical event in Guillain-Barré syndrome pathogenesis. To investigate the adhesion and transmigration phases of leukodiapedesis, we determined in a series of patients with GBS: (1) circulating levels of soluble forms of adhesion molecules (sICAM-1 and sVCAM-1); (2) attachment capacities of circulating lymphocytes to rICAM-1 and rVCAM-1; (3) fibronectin-penetrating capacities of circulating lymphocytes; and (4) lymphocyte intracellular concentrations of MMP-9 at the different phases of GBS and in healthy controls. Circulating levels of sVCAM-1 and sICAM-1 were above normal values at the time of progression, markedly increased at the time of plateau (sVCAM-1: P<0.03; sICAM-1: P<0.02), and tended to normalize during recovery. The percentage of cells with attachment capacities to rVCAM-1 and to rICAM-1 decreased from progression to recovery by 30 and 31%, respectively (P<0.02). The number of circulating lymphocytes with fibronectin penetrating capacities was lower than controls at the time of progression (P<0.01), then progressively increased to reach values higher than controls at the time of late recovery (P<0.02). Cellular concentrations of MMP-9 in circulating lymphocytes paralleled their fibronectin penetrating capacities. These results suggest early emigration of lymphocytes into nerve, followed by shedding of adhesion molecules from endothelium, and late decrease of lymphocyte adhesion capacities. Plateau and recovery are associated with accumulation in the vascular compartment of still proteolytically active lymphocytes that can no longer adhere to endothelial cells. Modulation of the adhesion step of leukodiapedesis may be crucially involved in the switch from progression to plateau of GBS.

Cerebral toxoplasmosis and Guillain-Barré syndrome after allogeneic peripheral stem cell transplantation

We report an unusual case of cerebral toxoplasmosis associated with Guillain-Barré syndrome (GBS) in a 25-year-old patient diagnosed with chronic myelogenous leukaemia (CML), who underwent a mismatched allogeneic peripheral stem cell transplantation (PSCT). On day +83 he started with fever, and 7 days later tremor, muscular weakness, diplopia, dysarthria, respiratory difficulty, and universal arreflexia appeared, compatible with GBS. As the patient had a positive cytomegalovirus (CMV) antigenemia, this was the aetiology suspected for his neurologic findings, but specific treatment failed to improve his clinical situation, and he died on day +123. Necropsy demonstrated cerebral toxoplasmosis and axonal degeneration of nerve roots compatible with the axonal form of GBS. Interestingly, the polymerase chain reaction (PCR) signal for Toxoplasma gondii in two different cerebrospinal fluid (CSF) samples had been negative. In addition, this case showed unique magnetic resonance imaging (MRI) abnormalities. We conclude that a negative PCR on CSF cannot exclude toxoplasmosis in a transplant patient, and we emphasise the importance of considering Toxoplasma as an aetiology of fever and neurological symptoms in the transplant setting.

Event-related potentials in patients with total locked-in state due to fulminant Guillain-Barré syndrome

A series of electrophysiological investigations were performed over a 6-month period in two patients affected by fulminant Guillain-Barré polyradiculoneuropathy, who developed an ascending paralysis leading, within 72 h, to flaccid quadriplegia, internal and external ophthalmoplegia, absence of all brainstem reflexes and no respiratory effort: the clinical state resembled brain death. Brain CTs were normal and spinal fluid examination revealed albuminocytological dissociation. All motor nerves tested were unexcitable, whereas sensory responses were markedly abnormal but present. Sequential EEG recordings revealed normal, partially reactive alpha rhythm in both patients. In one patient, normal auditory event-related potentials (ERPs: peak N1, P2, N2, P3, evoked in an 'oddball' paradigm) and CNV-like potentials could be recorded not earlier than the 20th day into the illness. In earlier recordings, N1 and P2 peaks as well as mismatch negativity (MMN) were present over the frontal and central scalp electrodes. This patient has now partially recovered motor functions and no cognitive defects are present, but he has little recollection of the events occurring in the first 2 weeks spent in the ICU, when he was completely paralyzed. The other patient generated normal N1 and P2 ERP peaks, but no N2, P3 and MMN were detected in a series of recordings. He died without having ever regained appropriate behavioral responses. The ERP abnormalities observed raise the matter of the origin of cognitive dysfunction in patients with severe and prolonged de-efferentation/de-afferentation. ERPs allow monitoring the level of alertness and attention and appear more specific than EEG in identifying a state of awareness in patients in which communication is severely impaired as a consequence of neurological disorders.

Inexcitability of nerves in a fulminant case of Guillain-Barré syndrome

A 45-year-old woman presented with a recent sensorimotor deficiency in all 4 limbs, and the next day she was totally paralyzed. A slight motor improvement began on day 27. The cerebrospinal fluid had normal cellularity, but the protein varied from 90 mg/dL on the first day to 800 mg/dL on day 15, and then 290 mg/dL on day 33. Electrophysiologic studies performed on days 15 and 23 revealed a universal peripheral nerve inexcitability. A superficial peroneal nerve biopsy was performed on day 23. Nine fascicles were examined on semi-thin sections and myelinated fiber damage varied greatly from one fascicle to another. At ultrastructural examination, certain axons were severely damaged, but the others were quite well preserved and were naked or wrapped in a myelin sheath presenting a multivesicular degeneration. A few fibers had a better-preserved myelin sheath that was sometimes dissociated by elongated processes from an invading histiocyte. Six cases of fulminant Guillain-Barré syndrome with inexcitability of nerves and ultrastructural examination of nerve fragments have been reported. Electrophysiologic study is often ambiguous and cannot determine the precise origin of such an axonal degeneration. Therefore, ultrastructural analysis of a nerve biopsy is mandatory in this setting.