Pathology of the motor-sensory axonal Guillain-Barré syndrome

Clinical epidemiology of Guillain-Barré syndrome in adults in Sweden 1996-97: a prospective study

We described clinical manifestations, outcomes, prognostic indicators and clinico-epidemiological subgroups for 53 adult patients with Guillain-Barré syndrome (GBS) in Sweden during the period 1996-97. These patients were identified from a population of 2.8 million inhabitants and prospectively followed up for one year by a network of neurologists. An additional 10 cases, of whom five were adults who had not been prospectively followed up, were not included in the analyses. At 6 months after onset 80% of the patients could walk without aid, while at 1 year 46% were fully recovered, 42% had mild residual signs or symptoms, 4% had moderate and 6% severe disabilities, and 2% had died. Intravenous human immunoglobulin or plasmapheresis were used in 72% of the patients. The sum of the Medical Research Council (MRC) score at nadir was found as the only significant predictor for residual signs at 1 year in a multivariate model. Three subgroups, with different clinico-epidemiological characteristics, were identified by using cluster analysis. In conclusion, GBS in Sweden is frequently preceded by a respiratory infection, is often treated with immunomodulatory therapies, and exhibits a high recovery rate and a low fatality rate.

Chronic inflammatory demyelinating polyneuropathy: immunopathological and ultrastructural study of peripheral nerve biopsy in 42 cases

The authors recently reexamined the peripheral nerve biopsies from 42 patients with chronic inflammatory demyelinating polyneuropathy (CIDP). There were 27 males and 15 females, aged from 9 to 84 years, and 13 had relapses. No patient had vasculitis, monoclonal gammopathy, tumor, diabetes mellitus, Lyme disease, familial neuropathy, HIV, or any other immune deficiency. In the endoneurium, perivascular inflammatory cell infiltrates were present in only one case, but scattered histiocytes marked by KP1 on paraffin-embedded fragments were present in every case and there were no T-lymphocytes. At ultrastructural examination macrophage-associated demyelination was observed in 17 cases, of which 6 had relapses separated by intervals of several months or years. Axonal lesions without associated primary demyelination were observed in 4 cases and 3 of these had relapses. Thirty-two patients had mixed lesions of demyelination and axonal involvement. This study confirms other recent data indicating that in all cases of CIDP, macrophages are present in the endoneurium. Macrophage-associated demyelination is the characteristic feature of demyelinating forms. On the other hand, isolated primary axonal forms, which have been known since 1989, are relatively frequent and prone to relapses.

Guillian Barré syndrome--recent advances

Guillian Barré Syndrome (GBS) is an acquired disease of the peripheral nerves that is characterized clinically by rapidly progressing paralysis, areflexia, and albumino-cytological dissociation. It affects both genders, involves people of all ages, is reported worldwide, and in the post-polio era, it is the most common cause of an acute generalized paralysis. The clinical features are distinct and a history and an examination generally lead to a high suspicion of the diagnosis that can then be confirmed by supportive laboratory tests and electrodiagnostic studies. This review discusses the recent advances in understanding of the different variants of GBS such as acute inflammatory demyelinating polyneuropathy (AIDP), acute motor axonal neuropathy (AMAN), acute motor sensory axonal neuropathy (AMSAN), and the Fisher syndrome. The clinical, electrodiagnostic criteria, immunopathogenesis, and management of GBS and its variants are discussed.

An endogenous pentapeptide acting as a sodium channel blocker in inflammatory autoimmune disorders of the central nervous system

Reversible blockade of sodium channels by endogenous substances has been claimed to account for the fast exacerbations and relapses commonly seen in demyelinating autoimmune diseases. Evidence has been provided that in the cerebrospinal fluid of patients with multiple sclerosis or Guillain-Barré syndrome, a sodium-channel-blocking factor exists that has properties of local anesthetic agents. This factor could contribute to the nerve conduction block and paresis seen in these disorders. We describe here a previously unknown endogenous substance in human cerebrospinal fluid with distinct channel-blocking properties even at very low (0.00001 M) concentrations. The pentapeptide with the sequence Gln-Tyr-Asn-Ala-Asp exerted its blocking action by shifting the steady-state inactivation curve of the sodium channels to more-negative potentials, as most local anesthetics do. In the cerebrospinal fluid of healthy individuals, its concentration was about 3 microM, whereas in patients with multiple sclerosis and Guillain-Barré syndrome, it increased 300-1,400%. At these concentrations, the peptide's blocking efficacy was higher than that of 50 microM lidocaine. At a concentration of 10 microM, lidocaine is able to 'unmask' subclinical lesions in multiple sclerosis; thus, the endogenous pentapeptide may well contribute to the fast changes of symptoms. Furthermore, it may become valuable as a marker of disease activity.

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.

New concepts of Guillain-Barré syndrome

Guillain-Barré syndrome is an acute autoimmune polyradiculoneuropathy with a clinical presentation of flaccid paralysis with areflexia, variable sensory disturbance, and elevated cerebrospinal fluid protein without pleocytosis. Although Guillain-Barré syndrome previously had been viewed as a unitary disorder with variations, it currently is viewed as a group of syndromes with several distinctive subtypes. These include the principal subtype prevalent in the Western world (acute inflammatory demyelinating polyradiculoneuropathy, and others, each with distinctive electrodiagnostic and pathologic features, including acute motor axonal neuropathy), acute motor-sensory axonal neuropathy, Miller Fisher syndrome, and perhaps others. The clinical and pathologic features of these Guillain-Barré syndrome subtypes are reviewed, and the role of antecedent infections, particularly Campylobacter jejuni gastroenteritis, and the role of antiganglioside antibody responses are reviewed with respect to pathogenesis. Treatment of Guillain-Barré syndrome includes both important supportive measures and immunotherapies, specifically high-dose intravenous immunoglobulin and plasma exchange.

Guillain-Barré syndrome occurring in two women after ketoacidosic comatose state disclosing an insulin-dependent diabetes mellitus

We report two women who presented with a Guillain-Barré syndrome just after a ketoacidosic comatose state disclosing an insulin-dependent diabetes mellitus. One had characteristic clinical signs and the other had major motor involvement. At neurophysiologic investigations, one had typical demyelinating neuropathy whereas the second had mainly axonal degeneration. At ultrastructural examination of a peripheral nerve biopsy, features of macrophage-associated demyelination were present in both nerve specimens, thus confirming the diagnosis of acute inflammatory demyelinating polyneuropathy, i.e., Guillain-Barré syndrome. Prominent axonal involvement was also present in the motor nerves of the second patient. Insulin therapy had to be permanently continued and these two cases are quite different from the transient diabetes sometimes observed in certain cases of Guillain-Barré syndrome. Both the latter and insulin-dependent diabetes mellitus probably have auto-immune mechanisms. It is likely that in our two patients both auto-immune diseases were triggered by a common event. Such cases of Guillain-Barré syndrome have to be distinguished from other acute diabetic neuropathies.

Acute axonal form of Guillain-Barré syndrome in a multiple sclerosis patient: chance association or linked disorders?

Multiple sclerosis (MS) is characterized by inflammation, demyelination and gliosis, involving the central nervous system (CNS) and commonly sparing the peripheral nervous system (PNS). Coexistence of CNS and PNS chronic demyelination has been rarely demonstrated in chronic inflammatory demyelinating polyradiculoneuropathies (CIDP) and in MS, but the occurrence of acute polyradiculoneuropathy in a patient with MS is even more unusual. We describe the case of a woman with relapsing-remitting MS who presented with an acute severe tetraparesis. Cerebrospinal fluid (CSF) examination together with neurophysiological data and sural nerve biopsy study demonstrated an axonal form of Guillain-Barré Syndrome (GBS). It remains unresolved if the association of an axonal form of GBS and MS is fortuitous or, on the contrary, is indicative of the coexistence in some individuals of common pathogenetic mechanisms.

Pathogenesis of Guillain-Barré syndrome

Recent neurophysiological and pathological studies have led to a reclassification of the diseases that underlie Guillain-Barré syndrome (GBS) into acute inflammatory demyelinating polyradiculoneuropathy (AIDP), acute motor and sensory axonal neuropathy (AMSAN) and acute motor axonal neuropathy (AMAN). The Fisher syndrome of ophthalmoplegia, ataxia and areflexia is the most striking of several related conditions. Significant antecedent events include Campylobacter jejuni (4-66%), cytomegalovirus (5-15%), Epstein-Barr virus (2-10%), and Mycoplasma pneumoniae (1-5%) infections. These infections are not uniquely associated with any clinical subtype but severe axonal degeneration is more common following C. jejuni and severe sensory impairment following cytomegalovirus. Strong evidence supports an important role for antibodies to gangliosides in pathogenesis. In particular antibodies to ganglioside GM1 are present in 14-50% of patients with GBS, and are more common in cases with severe axonal degeneration associated with any subtype. Antibodies to ganglioside GQ1b are very closely associated with Fisher syndrome, its formes frustes and related syndromes. Ganglioside-like epitopes exist in the bacterial wall of C. jejuni. Infection by this and other organisms triggers an antibody response in patients with GBS but not in those with uncomplicated enteritis. The development of GBS is likely to be a consequence of special properties of the infecting organism, since some strains such as Penner 0:19 and 0:41 are particularly associated with GBS but not with enteritis. It is also likely to be a consequence of the immunogenetic background of the patient since few patients develop GBS after infection even with one of these strains. Attempts to match the subtypes of GBS to the fine specificity of anti-ganglioside antibodies and to functional effects in experimental models continue but have not yet fully explained the pathogenesis. T cells are also involved in the pathogenesis of most or perhaps all forms of GBS. T cell responses to any of three myelin proteins, P2, PO and PMP22, are sufficient to induce experimental autoimmune neuritis. Activated T cells are present in the circulation in the acute stage, up-regulate matrix metalloproteinases, cross the blood-nerve barrier and encounter their cognate antigens. Identification of the specificity of these T cell responses is still at a preliminary stage. The invasion of intact myelin sheaths by activated macrophages is difficult to explain according to a purely T cell mediated mechanism. The different patterns of GBS are probably due to the diverse interplay between antibodies and T cells of differing specificities.

Asian paralysis syndrome

We report 20 children admitted to the paediatric ward of a public general hospital for acute flaccid paralysis, which was bilaterally symmetrical in all cases and was associated with bulbar involvement in eight of them. Recovery was partial. Nerve conduction studies showed motor axonal neuropathy. This new disease, variously termed as non-inflammatory neuropathy/Chinese paralysis syndrome must be differentiated from Guillain-Barré syndrome (GBS) and poliomyelitis. Both GBS and Asian paralysis syndrome have bilaterally symmetrical flaccid paralysis but GBS tends to have sensory involvement, full recovery occurs in 90% of cases and nerve conduction shows demyelinating neuropathy. Asian paralysis syndrome and poliomyelitis are pure motor lesions without sensory changes and partial recovery, but poliomyelitis differs in that paralysis is asymmetrical and unequal, muscle spasm is always present in the initial stage and there are prodromal symptoms. Nerve conduction studies show anterior horn cell disease. This new entity, common in Asian populations, assumes public health importance when it mimics poliomyelitis in a country that has tried to eliminate poliomyelitis by universal immunization. To the best of our knowledge, this is the first report of Asian paralysis syndrome in children in our area.

Epidemiological, clinical, and electrodiagnostic findings in childhood Guillain-Barré syndrome: a reappraisal

We evaluated 61 children with Guillain-Barré syndrome, 14 months to 14 years of age, admitted to the Hospital Nacional de Pediatria in Buenos Aires. According to the electrodiagnostic findings, they fit into two groups, those with acute motor axonal neuropathy (AMAN) (18 patients) and those with acute inflammatory demyelinating polyradiculoneuropathy (AIDP) (43 patients). Ninety percent of the children with AMAN resided in suburban or rural areas without running water, whereas half of the AIDP patients lived in a metropolitan district. Summer and winter months showed a higher incidence of both variants. Children with AMAN were younger, evolved more acutely, reached a higher maximum disability score, required assisted ventilation more often, had lower mean level of cerebrospinal fluid protein, improved more slowly, and had a poorer outcome 6 months and 12 months after onset. Electrophysiological findings in those with AIDP revealed a pattern of severe diffuse slowing in children 5 years old or younger and a multifocal pattern in children 6 years old or older. This difference was not reflected in the clinical picture. In contrast, AMAN showed a uniform pattern with normal sensory conduction, severely reduced compound muscle action potential amplitude, near normal conduction velocity, and early denervation. Epidemiological, clinical, electrodiagnostic, cerebrospinal fluid, and prognostic data indicate that these variants of Guillain-Barré syndrome should be regarded as different entities.

Acute motor axonal neuropathy and acute motor-sensory axonal neuropathy share a common immunological profile

Griffin and colleagues (Griffin JW, Li CY, Ho TW, Tian M, Gao CY, Xue P, Mishu B, Cornblath DR, Macko C, McKhann GM, Asbury AK. Pathology of motor-sensory axonal Guillain-Barré syndrome. Ann Neurol 1996;39:17-28 [4]) proposed that acute motor axonal neuropathy (AMAN) and acute motor-sensory axonal neuropathy (AMSAN) are part of the spectrum of a single type of immune attack on the axon. In contrast, IgG anti-GM1 antibody is associated closely with AMAN, but whether other IgG anti-ganglioside antibodies are associated with this neuropathy is not clear. We investigated whether IgG anti-ganglioside antibodies can be used as immunological markers to differentiate AMAN from acute inflammatory demyelinating polyneuropathy (AIDP) and whether these autoantibodies are present in AMSAN. The frequencies of anti-GM1, anti-GM1b, and anti-GD1a IgG antibodies in 21 AMAN patients were significantly higher than in 19 AIDP patients. Anti-GM1b and anti-GD1a IgG, as well as anti-GM1 IgG antibodies, therefore are immunological markers for AMAN. The patients with AMSAN had anti-GM1, anti-GM1b, and anti-GD1a IgG antibodies, indicative that AMAN and AMSAN share a common immunological profile.

Structure-function studies of an anti-asialo GM1 antibody obtained from a phage display library

Although gangliosides elicit human autoantibodies, they are extremely weak immunogens in mice. We obtained a monoclonal antibody Fab fragment (clone 10) that is specific for asialo GM1 (GA1), from a phage display library. The Vkappa domain of clone 10 could be replaced by two different Vkappa domains without changing the specificity of the antibody. Mutagenesis of the third hypervariable regions of the heavy and light chains of clone 10 yielded three mutants that exhibited a 3 to 4 times increase in avidity for GA1. A molecular model of clone 10 indicated that the putative antigen-binding site contained a shallow surface pocket. These data illustrate the use of recombinant DNA techniques to obtain anti-ganglioside antibodies, and to explore the molecular basis of their antigen-binding activity.

Acute sensory neuropathy in an adolescent girl following BCG vaccination

A 13-year-old girl developed a sensory neuropathy following bacille Calmette-Guérin (BCG) vaccination, consistent with acute inflammatory demyelinating polyradiculoneuropathy or acute sensory axonal neuropathy.

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

We performed electrophysiological and serological testing within 15 days of symptom onset on 369 patients with Guillain-Barré Syndrome (GBS) enrolled in a trial comparing plasma exchange, intravenous immunoglobulin, and both treatments. Patients were classified into five groups by motor nerve conduction criteria; 69% were demyelinating, 3% axonal, 3% inexcitable, 2% normal, and 23% equivocal. Six of 10 (60%) patients with axonal neurophysiology had had a preceding diarrheal illness compared with 71 of 359 (20%) in other groups. Antiganglioside GM1 antibodies were present in a higher proportion of patients with axonal physiology or inexcitable nerves than other patients. The number dead or unable to walk unaided at 48 weeks was greater in the group with initially inexcitable nerves (6 of 12, 50%) compared with the rest (52 of 357, 15%), but was not significantly different between the axonal (1 of 10, 10%) and demyelinating (44 of 254, 17%) groups. Sensory action potentials and clinical sensory examination were both normal in 53 of 342 (16%) patients, and these "pure motor GBS" patients were more likely than other GBS patients to have IgG antiganglioside GM1 antibodies and to have had preceding diarrhea but had a similar outcome. The axonal group was more likely than other groups to have normal sensory action potentials. The outcomes in response to the three treatments did not differ in any subgroup (including patients with pure motor GBS or preceding diarrhea) or any neurophysiological category.

Expression of integrins in experimental autoimmune neuritis and Guillain-Barré syndrome

Integrins are a subclass of adhesion molecules that mediate cell-cell and cell-extracellular matrix interactions. Integrins influence transendothelial migration of lymphocytes and monocytes and are suitable targets for experimental immunotherapy. They are critically involved in the pathogenesis of autoimmune neuritis and abnormally expressed in human neuropathies. Also, the role of integrins in myelination, neurite outgrowth, and nerve regeneration suggests that they could be involved in the recovery phase of immune-mediated neuropathies. We investigated by immunohistochemistry the expression of a number of integrin subunits during the course of experimental autoimmune neuritis (EAN). Results were compared with the human immune neuropathy Guillain-Barre syndrome (GBS) and extended in vitro. Inflammation and demyelination in both EAN and GBS induced the down-regulation of beta4 integrin in Schwann cells (SCs), whereas loss of alpha2 was noted only in EAN. When axonal loss was present, SCs displayed alpha5 integrin, in both EAN and GBS. In vitro, basal lamina and inflammatory cytokines modulated the expression of beta4 in SCs, but they did not influence alpha2 and alpha5 expression. Finally, integrins were differentially expressed in blood vessels during EAN. In conclusion, the spatiotemporal changes in integrin expression may be used to characterize, stage, and better understand the pathogenesis and evolution of inflammation during GBS and EAN. This may help to establish useful, novel therapy for immune-mediated neuropathies.

Subacute inflammatory polyneuropathy: two cases with plasmacytoid histiocytes in the endoneurium

Inflammatory polyneuropathies are mainly known by their acute form, Guillain-Barré syndrome, but there are also chronic cases and all are considered as having an autoimmune mechanism. In each form, peripheral nerve biopsies show scattered macrophages in the endoneurium and in certain cases macrophages invade the Schwann cell cytoplasm and destroy the myelin sheath. In rarer cases there is a primary axonal degeneration. The authors studied two chronic cases, which both exhibited mixed primitive axonal and demyelinating lesions, with peculiar histiocytes in the endoneurium. These rounded cells were characteristically well marked by KP1 but showed well-developed rough endoplasmic reticulum cysternae at ultrastructural examination. Such plasmacytoid histiocytes have mainly been studied in subacute lymphadenopathies and have been only briefly illustrated in a few cases of peripheral neuropathies due to Lyme disease or HIV infection. The two cases reported here had no associated diseases and probably correspond to a peculiar subacute autoimmune reaction.

Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is viewed as a reactive, self-limited, autoimmune disease triggered by a preceding bacterial or viral infection. Campylobacter jejuni, a major cause of bacterial gastroenteritis worldwide, is the most frequent antecedent pathogen. It is likely that immune responses directed towards the infecting organisms are involved in the pathogenesis of GBS by cross-reaction with neural tissues. The infecting organism induces humoral and cellular immune responses that, because of the sharing of homologous epitopes (molecular mimicry), cross-react with ganglioside surface components of peripheral nerves. Immune reactions against target epitopes in Schwann-cell surface membrane or myelin result in acute inflammatory demyelinating neuropathy (85% of cases); reactions against epitopes contained in the axonal membrane cause the acute axonal forms of GBS (15% of cases). Care for such patients may be challenging, yet the prognosis overall is favourable. Optimal supportive care and anticipation and prevention of complications are the mainstay of therapy. Admission to the intensive-care unit is necessary in 33% of patients who require intubation and assisted ventilation. Immunomodulation with infusions of IgG or plasma exchange treatments foreshorten the disease course.

Demyelinating inflammatory neuropathies, including Guillain-Barré syndrome

The highly complex and multiple mechanisms responsible for the development of demyelinating neuropathies are reviewed, in particular Guillain-Barré syndrome and its variant Miller Fisher syndrome, chronic inflammatory demyelinating neuropathy, multifocal motor neuropathy, anti-myelin-associated glycoprotein neuropathy, as well as experimental models. Recent investigations into the role of auto antibodies against myelin proteins, or glycolipids have given insights into the pathogenesis of demyelinating inflammatory neuropathies.

Microtiter assay for detecting Campylobacter spp. and Helicobacter pylori with surface gangliosides which bind cholera toxin

Campylobacter jejuni with Gm1 ganglioside in the core of its lipopolysaccharide has been associated with Guillain-Barré syndrome. Since this epitope may be of considerable pathophysiologic importance and since this ganglioside binds cholera toxin, a rapid screening assay to detect bacteria that bind cholera toxin as an indication of Gm1 on their surfaces was developed. In the assay, bacterial lawns were grown on agar plates, harvested with phosphate-buffered saline, boiled, and incubated with a standard concentration of cholera B subunit. Preparations from strains with Gm1 were observed to inhibit the binding of cholera B subunit to Gm1 in a microtiter enzyme-linked immunosorbent assay. By using this assay with two groups of strains, 37 positive strains were detected among the 197 tested. Species with positive isolates included C. jejuni, Campylobacter coli, and Helicobacter pylori. The assay is capable of testing large numbers of isolates and should prove useful in future clinical and epidemiological studies of bacteria with this epitope.

Campylobacter species and Guillain-Barré syndrome

Since the eradication of polio in most parts of the world, Guillain-Barré syndrome (GBS) has become the most common cause of acute flaccid paralysis. GBS is an autoimmune disorder of the peripheral nervous system characterized by weakness, usually symmetrical, evolving over a period of several days or more. Since laboratories began to isolate Campylobacter species from stool specimens some 20 years ago, there have been many reports of GBS following Campylobacter infection. Only during the past few years has strong evidence supporting this association developed. Campylobacter infection is now known as the single most identifiable antecedent infection associated with the development of GBS. Campylobacter is thought to cause this autoimmune disease through a mechanism called molecular mimicry, whereby Campylobacter contains ganglioside-like epitopes in the lipopolysaccharide moiety that elicit autoantibodies reacting with peripheral nerve targets. Campylobacter is associated with several pathologic forms of GBS, including the demyelinating (acute inflammatory demyelinating polyneuropathy) and axonal (acute motor axonal neuropathy) forms. Different strains of Campylobacter as well as host factors likely play an important role in determining who develops GBS as well as the nerve targets for the host immune attack of peripheral nerves. The purpose of this review is to summarize our current knowledge about the clinical, epidemiological, pathogenetic, and laboratory aspects of campylobacter-associated GBS.

Molecular mimicry in Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is the commonest cause of acute flaccid paralysis worldwide. Recent pathological and electrodiagnostic studies indicated that there are different patterns within this syndrome. The demyelinating pattern predominates in North America and Europe, whereas axonal variants of GBS occur more frequently in Northern China. Infection with Campylobacter jejuni is one of the most frequently recognized antecedent events in all variants of GBS. The lipopolysaccharides of these organisms share ganglioside-like epitopes with peripheral nerves, and patients with GBS have antiganglioside antibodies. These observations have given rise to the hypothesis that "molecular mimicry" is the immunopathogenic mechanism of injury to peripheral nerve fibers. With this hypothesis in view, we summarize our experience of GBS as it occurs in Northern China. To explore the role of molecular mimicry in this cohort we sought evidence of preceding Campylobacter infection and correlated this with clinical characteristics and antiganglioside serology. Based on our results we propose a sequence of pathogenic events leading to peripheral nerve injury in GBS.

Guillain-Barré syndrome and Fisher's syndrome following Campylobacter jejuni infection

The patients with Guillain-Barré Syndrome (GBS) subsequent to Campylobacter jejuni enteritis showed axonal degeneration and had IgG anti-GM1 antibody. The most frequently isolated C. jejuni from the patients was specific serotype of Penner's 19 in Japan. In the lipopolysaccharide (LPS) in C. jejuni of this serotype, the same oligosaccharide structure as GM1 ganglioside existed, suggesting the molecular mimicry between GM1 in nervous tissue and C. jejuni LPS. IgG anti-GM1 antibody may bind the nodes of Ranvier and axon terminals and causes degeneration of the motor axon. Some patients develop Fisher's syndrome following C. jejuni infection. C. jejuni strains from the patients who had IgG anti-GQ1b antibody in the acute phase had GQ1b epitope in their LPS, and the molecular mimicry between GQ1b in nervous tissue and an antecedent infectious agent was clarified.

Guillain-Barré syndrome after Cyclospora infection

We present a patient who developed Guillain-Barré syndrome (GBS) after a Cyclospora-induced diarrheal illness. We raise the possibility that Cyclospora is an infectious trigger for GBS in this patient. An active search for this agent in patients with GBS preceded by diarrheal illness is recommended.

Neuromuscular disorders and acute respiratory failure

This article discusses the assessment and management of rapidly progressive weakness due to neuromuscular disorders. The authors review elements helpful in determining the causes of weakness including pertinent history and laboratory studies. Disorders are classified according to the level of the motor unit involved and triage/management decisions are described. In addition, respiratory function assessment is reviewed. The latter part of this article is devoted to evaluation and management of two of the most common disorders, Guillain-Barré syndrome and myasthenia gravis.

Human autoimmune neuropathies

Peripheral nerve diseases are among the most prevalent disorders of the nervous system. Because of the accessibility of the peripheral nervous system (PNS) to direct physiological and pathological study, neuropathies have traditionally played a unique role in developing our understanding of basic mechanism of nervous system injury and repair. At present they are providing new insight into the mechanisms of immune injury to the nervous system. A rapidly growing catalogue of PNS disorders are now suspected to be immune-mediated, and in the best understood of these disorders, the molecular and cellular targets of immune attack are known, and the pathophysiology follows directly from the specific immune injury. This review summarizes the immunologically relevant features of the PNS, then considers selected immune-mediated neuropathies, focusing on pathogenetic mechanisms. Finally, the PNS is providing a testing ground for new immunotherapies and approaches to protection and regeneration, including the use of trophic factors. The current status of treatment and implications for future approaches is reviewed.

Matrix metalloproteinases MMP-9 and MMP-7 are expressed in experimental autoimmune neuritis and the Guillain-Barré syndrome

Matrix metalloproteinases (MMPs) are a family of enzymes that may be implicated in the pathogenesis of inflammatory demyelinating disorders such as multiple sclerosis. The present study investigated the expression of 92-kd gelatinase (MMP-9) and five other MMPs in sciatic nerve from Lewis rats with autoimmune experimental neuritis (EAN), an experimental model of the Guillain-Barré syndrome (GBS). Quantitative polymerase chain reaction analysis revealed an up-regulation of MMP-9 mRNA with peak levels concurrent with maximal disease severity. Increased mRNA expression was associated with enhanced enzyme activity, as detected by gelatin zymography. Immunohistochemically, MMP-9 could be localized primarily around blood vessels within the epineurium and endoneurium in diseased but not normal sciatic nerve. Among all other MMPs investigated, mRNA levels of matrilysin (MMP-7) were found to be up-regulated at the peak of the disorder, remaining at high levels throughout the clinical recovery phase of the disease. To apply these findings to human disease, sural nerve biopsies from GBS patients were examined. By using immunohistochemistry, positive immunoreactivity against MMP-9 and MMP-7 was noted and corroborated by demonstrating augmented mRNA expression in comparison with noninflammatory neuropathies. Furthermore, increased MMP-9 activity was detected by zymography. These findings indicate that 92-kd gelatinase and matrilysin are selectively up-regulated during EAN and expressed in nerves of GBS patients and thus may contribute to the pathogenesis of inflammatory demyelination of the peripheral nervous system.

Electrophysiological studies in the critical care unit: investigating polyneuropathies

Polyneuropathies frequently contribute to ventilator dependency and prolonged stay in the intensive care unit. As clinical examination is often limited in critically ill patients, electrophysiological studies are invaluable in establishing the diagnosis of neuropathy, determining its pathophysiology, severity and in following the patients' progression. Guillain-Barré syndrome (GBS) developing before intensive care unit admission and critical illness polyneuropathy (CIP) developing as a complication of sepsis and multiorgan failure are the commonest causes of neuropathy. Electrophysiological findings in CIP are that of an axonal neuropathy whereas the findings in GBS are usually consistent with a demyelinating neuropathy. Axonal GBS can be distinguished from CIP by the preceding illnesses, slow nerve conduction velocity in some cases, lack of spontaneous activity on the initial needle electromyographic study and cerebrospinal fluid findings.

Guillain-Barré syndrome in Taiwan: a clinical study of 167 patients

OBJECTIVE

To identify clinical characteristics of various forms of Guillain-Barré syndrome in Taiwan.

METHODS

The clinical and electrophysiological data of 167 consecutive patients with Guillain-Barré syndrome admitted to Chang Gung Memorial Hospital, a general paediatric and adult hospital in Taiwan, were reviewed.

RESULTS

Analysis of age distribution disclosed a high incidence (21%) among patients under the age of 10 years. Seasonal preponderance in Spring (March to May) was found. Utilizing clinical and electrophysiological data, these 167 patients with Guillain-Barré syndrome were subclassified; 82 (49%) had acute inflammatory demyelinating polyradiculoneuropathy (AIDP), 32 (19%) had Fisher syndrome (FS), and six (4%) had axonal forms of Guillain-Barré syndrome. The remaining 47 (28%) patients were unclassified. Patients with AIDP and FS had many common clinical features, including seasonal distribution, history of preceding illness, sensory abnormalities, cranial nerve involvement except for extraocular motor nerves, and albuminocytological dissociation on examination of CSF. Follow up study on 145 patients disclosed that 127 (87%) recovered satisfactorily, 14 (10%) were persistently disabled, and four (3%) died during admission to hospital. Clinical features associated with poor outcome (persistent disability or death) were requirement for mechanical ventilation, a low mean compound muscle action potential amplitude (< or = 10% of the lower limit of normal), and age greater than 40 years.

CONCLUSION

Guillain-Barré syndrome in Taiwan showed a peculiar age and seasonal distribution and a high frequency of FS not seen in other series. Given that patients with AIDP and FS had many common clinical features, AIDP and FS may have similar underlying pathological mechanisms.

Acute peripheral neuropathy in adults. Guillain-Barré syndrome and related disorders

Acute paralysis in adults has an extensive assortment of etiologies. Guillian-Barré syndrome is the most common cause of acute neuropathy in adults. This review emphasizes pathophysiology, clinical features, differential diagnosis, and a practical approach to the laboratory work-up for patients with suspected Guillian-Barré syndrome. The current status of immunotherapy is reviewed.

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

The pathological basis of nerve inexcitability in Guillain-Barré syndrome has not been established with certainty. We report the clinicopathological findings in a 67-year-old patient with fulminant Guillain-Barré syndrome who died 18 days after onset. Three serial electrophysiological studies revealed nerve inexcitability. Antibodies to Campylobacter jejuni were present but there was no antiganglioside reactivity. Spinal root sections revealed extensive and almost pure macrophage-associated demyelination with occasional presence of T lymphocytes and neutrophil leukocytes. Conversely, in femoral, median, and sural nerves the outstanding lesion was axonal degeneration, with some denuded axons remaining. Unmyelinated fibers, posterior root ganglia, and dorsal columns were preserved. Endoneurial postcapillary venules showed plump endothelial cells with loss of their tight junctions. We conclude that both primary demyelination and axonal degeneration secondary to inflammation account for nerve inexcitability. Our findings lend support to the hypothesis of increased endoneurial pressure as the cause of wallerian degeneration in nerve trunks.

Evaluation and treatment of respiratory failure in neuromuscular disease

Respiratory failure is a relatively uncommon feature of most neuromuscular disease. It accounts for most of the morbidity and mortality associated with these disorders, however. In most cases, aggressive supportive care, specific immunologic treatment, and treatment of associated medical conditions result in improvement in respiratory function and a favorable outcome.

October 1996--rapidly progressive weakness

One week after a flu-like illness, a 51-year-old woman developed rapidly progressive weakness. Within three weeks, she required mechanical ventilation. A neurological exam revealed severe motor involvement with normal sensory findings confirmed by nerve conduction studies. Five days after intubation a catastrophic brain hemorrhage occurred. Autopsy showed severe loss of axons in the motor roots with periaxonal macrophages and no lymphocytes. These findings are typical of acute motor axonal neuropathy, which is rare in the United States.

Acute motor axonal neuropathy: an antibody-mediated attack on axolemma

The acute motor axonal neuropathy (AMAN) form of the Guillain-Barre syndrome is a paralytic disorder of abrupt onset characterized pathologically by motor nerve fiber degeneration of variable severity and by sparing of sensory fibers. There is little demyelination or lymphocytic inflammation. Most cases have antecedent infection with Campylobacter jejuni and many have antibodies directed toward GM1 ganglioside-like epitopes, but the mechanism of nerve-fiber injury has not been defined. In 7 fatal cases of AMAN, immunocytochemistry demonstrated the presence of IgG and the complement activation product C3d bound to the axolemma of motor fibers. The most frequently involved site was the nodal axolemma, but in more severe cases IgG and C3d were found within the periaxonal space of the myelinated internodes, bound to the outer surface of the motor axon. These results suggest that AMAN is a novel disorder caused by an antibody- and complement-mediated attack on the axolemma of motor fibers.

Experimental Campylobacter jejuni infection in the chicken: an animal model of axonal Guillain-Barré syndrome

OBJECTIVE

To develop and characterise an animal model of paralytic neuropathy after Campylobacter jejuni infection. Campylobacter infection precedes development of many cases of Guillain-Barré syndrome and is particularly associated with cases having prominent axonal degeneration. Understanding the pathogenesis of Guillain-Barré syndrome after C jejuni infection has been slowed by the lack of animal models.

METHODS

A spontaneous paralytic neuropathy is described that developed in chickens from the farms of four patients with Guillain-Barré syndrome. The production of paralytic neuropathy in chickens experimentally fed Campylobacter jejuni isolated from one of these patients is reported. The sciatic nerves of the spontaneously paralysed chickens were examined pathologically in teased fibres, in plastic embedded sections, and by electron microscopy. Two large groups of chickens were then fed cultures of a C jejuni (Penner type O:19) isolated from one of these patients.

RESULTS

The chickens with spontaneous paralysis had pathologically noninflammatory neuropathy. Pathology in the sciatic nerves ranged from no detectable changes to severe Wallerian-like degeneration. In the experimentally inoculated groups, an average of 33% of the chickens became paralysed. The median time after inoculation to paralysis was 12 days. The lesions found in the first few days of paralysis included nodal lengthening and paranodal demyelination. In those animals that survived for several days after onset of weakness, the pathology was dominated by extensive Wallerian-like degeneration. Animals that survived for weeks with no clinically apparent neuropathy had paranodal remyelination in some teased nerve fibres, reflecting earlier paranodal demyelination.

CONCLUSION

Experimental inoculation with C jejuni may provide a new model for understanding some forms of Guillain-Barré syndrome.

Antibodies to GM1 and Gal(beta 1-3)GalNAc at the nodes of Ranvier in human and experimental autoimmune neuropathy

Autoantibodies to Gal(beta 1-3)GalNAc epitopes on glycolipids and glycoproteins are associated with motor neuron disease and motor or sensorimotor neuropathy. These epitopes are ubiquitously distributed on cell surfaces. In the nervous system they are present on axons and myelin, specifically also at the nodes of Ranvier. Binding of GM1 antibodies to the nodal area may contribute to disease development in some of these conditions.

Immune attack on the Schwann cell surface in acute inflammatory demyelinating polyneuropathy

The localization, mode of action, and roles of complement in the Guillain-Barre syndrome have been controversial. We used high-resolution immunocytochemistry to localize complement activation products in early stages of the acute inflammatory demyelinating polyneuropathy (AIDP) pattern of Guillain-Barre syndrome. Three AIDP subjects who were autopsied had had symptoms for 3 to 9 days at the time of death. Immunocytochemistry was performed on etched, epoxy resin-embedded sections, and the next thin section was compared by electron microscopy (thick/thin sections). Many fibers had a rim of the complement activation marker C3d and the terminal complement complex neoantigen C5b-9 along the outer surface of the Schwann cells. Ultrastructural analysis of these C3d-positive fibers showed mild vesicular changes of the outermost myelin lamellae. Vesicular degeneration was seen before the invasion of macrophages into the myelin, and was the predominant change in the subject with symptoms for 3 days. C3d staining was not found on myelin membranes. The results suggest that at least some forms of AIDP are complement mediated. We speculate that complement is activated by antibody bound to epitopes on the outer surface of the Schwann cell and that the resulting complement activation initiates the vesiculation of myelin.

Early nodal changes in the acute motor axonal neuropathy pattern of the Guillain-Barré syndrome

The axonal patterns of Guillain-Barré syndrome, associated in many cases with antecedent Campylobacter jejuni infection, are now recognized as frequent causes of acute flaccid paralysis in some regions of the world. This study examined ultrastructurally the PNS of seven cases of the acute motor axonal neuropathy form of Guillain-Barré syndrome. In this disorder previous studies of advanced cases have found Wallerian-like degeneration of motor fibres in the spinal roots and peripheral nerves, with little lymphocytic inflammation or demyelination. The present study was focused on identifying early changes and establishing the sequence of changes. By electron microscopy the earliest and mildest changes consisted of lengthening of the node of Ranvier with distortion of the paranodal myelin, and in some instances with breakdown of the outermost myelin terminal loops. At this stage many nodes had overlying macrophages which extended their processes through the Schwann cell basal lamina covering the node and apposed the axolemma. Macrophage processes then extended beneath the myelin terminal loops, and the whole macrophage entered the periaxonal space at the paranode. Macrophage processes dissected the axon from the adaxonal Schwann cell plasmalemma and the macrophages advanced into the internodal periaxonal space, where they typically surrounded a condensed-appearing axon. At this stage the adaxonal Schwann cell cytoplasm regularly degenerated and disappeared, so that the periaxonal space was bounded by the innermost myelin lamella, and the axolemma of many fibres could not be seen. The internodal myelin sheath and the abaxonal Schwann cell cytoplasm remained normal. This arrangement appeared to be stable for some time, but in many fibres the axon subsequently underwent Wallerian-like degeneration. By interfering with impulse conduction, these nodal and periaxonal changes may explain paralysis in some pathologically mild cases. In addition, at early stages, these changes may be reversible, thus explaining the rapid recovery of some patients who become paralysed with acute motor axonal neuropathy. These observations, taken together with previous studies, suggest that acute motor axonal neuropathy is an antibody- and complement-mediated disorder in which the relevant epitopes are present on the nodal and internodal axolemma.