Peripheral nervous system pathology in relapsing experimental allergic encephalomyelitis

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.

Linkage of multiple sclerosis and guillain-barre syndrome: a population-based survey in isfahan, iran

Background. Multiple Sclerosis (MS) and Guillain Barre Syndrome (GBS) are autoimmune demyelinating disorders of Central and Peripheral Nervous system, respectively. The coexistence of these two syndromes in an individual's life span is rare. Objectives. To inspect throughout Isfahan MS society (IMSS) records for MS cases who had history of documented GBS whether before the onset of MS or after it. Methods. This retrospective survey was carried out by analyzing the clinical records of 3,522 MS patients who were registered with IMSS, from April 2003 to July 2010. Eligible cases were requested to attend to IMSS for final clinical/paraclinical examinations. Results. Among 3,522 (2,716 women and 806 men) MS subjects, we could identify seven patients (six females and one male) with documented diagnosis of GBS. Six patients (five women and one man) had developed MS within 6.5 ± 7.0 (range: 1–16) years after being diagnosed with GBS and one (a woman) had developed GBS three years after the diagnosis of MS. Conclusion. It seems that the development of MS in individuals with history of GBS is more than a simple incidental event.

Chronic inflammatory demyelinating polyradiculoneuropathy associated with multiple sclerosis

OBJECTIVE

To describe temporal profile of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) in patients with definite, relapsing multiple sclerosis (MS).

BACKGROUND

Peripheral demyelinating neuropathy has been rarely reported in association with central nervous system demyelinating disorder indistinguishable from MS.

METHODS

In addition to usual diagnostic studies for CIDP and MS in all 5 patients, we studied proximal segments of nerves using deep tendon reflex latency measurements of biceps reflex, patellar reflex, and ankle reflex.

RESULTS

All patients with MS subsequently (4-22 years) developed definite CIDP. Two of these patients developed multiple cranial nerve and spinal root enhancement on subsequent imaging without new intraparenchymal enhancement after a diagnosis of CIDP. The deep tendon reflex latencies were prolonged at more than 2 sites in all patients. Cerebral spinal fluid protein increased (70 +/- 19 to 144.8 +/- 17.4 mg/dL, P = 0.0001) at time of diagnosis of CIDP. Clinical improvement was observed in all patients after intravenous immunoglobulin therapy.

CONCLUSIONS

When patients with MS develop CIDP, manifestations of central and peripheral disease involvement seem to respond to intravenous immunoglobulin. These cases suggest that there may be common antigenic targets in central and peripheral nervous system in this subset of patients.

Microfluorimetry defines early axonal damage in a rat model of optic neuritis: a novel method targeting early CNS autoimmunity

Autoimmune optic neuritis is a common early manifestation of multiple sclerosis (MS), yet early therapeutic interventions for MS often have high ocular toxicity associated with increased risks for glaucoma, cataract, or retinopathy. This need to discover better early treatment options prompted our development of a sensitive and reliable means to quantify the broad range of pathologies that potentially develop very early in autoimmune optic neuritis. Tissue microfluorimetry was used to measure seven established markers for human MS pathology in normal and autoimmune optic nerves 13 days after antigen exposure, in a Brown Norway rat model of myelin oligodendrocyte glycoprotein (MOG) peptide (35-55)-induced autoimmune optic neuritis. Optic neuritis rats demonstrated early and significant pathologic changes in five established indices for neuroinflammation, immune infiltration, and demyelination that accurately modeled pathologies characteristic of MS. Two indices of MS-like axon damage advanced significantly within 13 days of antigen exposure. Fluorimetrically measured immunoreactivity (-ir) was significantly decreased for paranodin (PN, the requisite axonal paranodal junction protein) and significantly increased for amyloid precursor protein (APP), indicating loss of paranodal junctions and impaired fast axonal transport, respectively. Measurements showing decreased PN-ir with increased APP-ir quantitatively defined a pattern of early axonal damage in autoimmune optic neuritis.

Demyelinating neuropathy in a patient with multiple sclerosis and genotypical HMSN-1

Patients with multiple sclerosis (MS) may develop a peripheral neuropathy, sometimes attributed to nutritional deficiency. Other patients present with a demyelinating neuropathy which is presumed to be the result of an autoimmune process that affects both the central and peripheral nervous systems. We report a case of concurring MS and demyelinating neuropathy, without a positive family history, in whom genetic testing proved the neuropathy to be hereditary and not autoimmune. Hereditary neuropathy should be a consideration in sporadic cases of peripheral neuropathy and MS.

Peripheral neuropathy in multiple sclerosis: a clinical and electrophysiologic study

Peripheral nerve abnormalities are uncommon in multiple sclerosis (MS). When present, they are usually attributed to factors associated with advanced disease, such as malnutrition or cytotoxic drugs. We prospectively evaluated 22 mildly disabled MS patients with sensory complaints for evidence of neuropathy using the Neuropathy Symptom Score (NSS), clinical examination, and electrophysiologic studies of peripheral nerves. Distal latency, F-wave response, and nerve conduction velocity (NCV) and amplitude in the ulnar, median, tibial, peroneal and sural nerves were examined. Neuropathy was recorded if electrophysiologic abnormalities were detected in at least two peripheral nerves in the same patient. The most frequent electrophysiologic abnormalities noted were prolonged F-wave response and low motor amplitude in the peroneal nerve, slow sensory conduction velocities of the ulnar and sural nerves, and prolonged distal latencies in the sensory ulnar and sural nerves. Electrophysiologic abnormalities were found in 33 of 244 nerves examined (14.7%) and occurred in 10 patients (45.5%). Neuropathic symptoms were mild and did not correlate with electrophysiologic abnormalities. Age, disease duration, disease course and neurologic disability as evaluated by the Kurtzke Expanded Disability Status Scale, were not associated with the presence of neuropathy. Our findings indicate a high frequency of sensory-motor neuropathy in a selected group of MS patients.

T cell immunity to myelin basic protein induces anterior uveitis in Lewis rats

Uveitis of unknown etiology is known to occur in association with various systemic disorders. We now report that anterior uveitis (AU) can be produced by T cell immunity to myelin basic protein (BP) and accompanies experimental autoimmune encephalomyelitis (EAE). EAE with AU was induced in Lewis rats by immunization to BP in CFA or by immunization to various BP peptides including the encephalitogenic 71-90 peptide. Slit-lamp biomicroscopy of BP-immunized Lewis rats revealed AU, characterised by inflammation of the iris, in 73% of the eyes. The onset of AU in actively immunized rats varied between days 12 and 26, often appearing after spontaneous remission of the paralysis, the hallmark of EAE. The course of AU was progressive, affecting more than 50% of the surface of the iris in 16 of 29 diseased eyes. Like the paralysis, the AU was self-limiting: within 2 weeks the disease remitted. In addition, AU could be adoptively transferred to naive and irradiated rats by a T cell clone specific for BP peptide 71-90. The present observations are compatible with the idea that AU may be triggered by BP-reactive T cells. The myelinated nerves present in the iris have been shown to contain BP. However, these peripheral nerves would now appear to be the only peripheral nerves susceptible to acute EAE.

Associated polyneuropathy and demyelinating disease. Case report

We report a case in which an acute Guillain-Barré-like syndrome was quickly followed by a central demyelinating disease, documented by the clinical findings as well as by magnetic resonance imaging (MRI), electrophysiological and cerebrospinal fluid examinations. The close follow-on of the clinical signs seems to exclude a simple coincidence of two separate diseases and it may constitute further evidence for a possible etiological link between central and peripheral myelin damage. We discuss the possibility of a common pathogenic factor underlying central and peripheral demyelination.

[Late recurrence of Miller-Fischer syndrome. Physiopathogenic reflections about a case]

The physiopathology of the syndrome of ophtalmoplegia-ataxia-areflexia-hyperproteinorachia, firstly described by FISHER in 1956, remains a matter of controversy among neurologists. We report a new case of recurrence of a MILLER-FISHER's syndrome. The involvement of peripheral and central structures is discussed according to recent knowledges about the immunopathology of inflammatory polyneuropathies.

Sites of egress of inflammatory cells and horseradish peroxidase transport across the blood-brain barrier in a murine model of chronic relapsing experimental allergic encephalomyelitis

Results are reported of experiments designed to focus at attachment sites of inflammatory cells (ICs) on the luminal surface of brain endothelial cells (ECs) and on the mechanisms of horseradish peroxidase (HRP) transport across the altered blood-brain barrier (BBB) in a murine model of chronic relapsing experimental allergic encephalomyelitis. Cationized ferritin (CF) served as a marker for evaluating the electrostatic nature of brain microblood vessels (MBVs) on the plasma membranes of ICs or normal mouse peripheral white blood cells and erythrocytes. SJL/J mice demonstrating clinical illness were given HRP or CF, in vivo or in situ, respectively. Light microscopy and conventional transmission electron microscopy of cerebellum or thoracic and lumbar spinal cord regions demonstrated HRP leakage most pronounced in MBVs with perivascular infiltrates. HRP traversed across the ECs via numerous vesicles and tubular profiles located mostly in the parajunctional regions, while EC junctions appeared closed. Scanning electron microscopy demonstrated that IC attachment was primarily at parajunctional sites on the EC surface. We also observed increased microvillar projections extending from the EC surface into the lumen. CF demonstrated a patchy decoration on both the luminal EC surface and IC membranes but did not label uncoated invaginating membrane pits or tubular structures. Our data indicate that the points of attachment of the ICs on the EC surface may reflect specific receptor sites where the ICs eventually gain entrance into CNS across the BBB during brain inflammation.

Double myelination of axons in the sympathetic nervous system of the mouse. I. Ultrastructural features and distribution

This study has examined the structural features and distribution of 'doubly myelinated' axons in normal adult and aged mice. Investigation focused on the superior cervical ganglion (SCG) and paravertebral sympathetic ganglia, which were extensively serial-sectioned for light and electron microscopy. In the SCG, the principal features of doubly myelinated regions were that an apparently normal myelinated axon was enclosed for part of its length by an additional (outer) myelinating Schwann cell. The separate nature of the inner and outer Schwann cells was emphasized by the consistent presence of individual nuclei in each, and by the presence of endoneurial space, often containing collagen fibrils, between the inner and outer cells. In some cases more than a single outer Schwann cell was present, arranged serially along the inner myelinated fibre. While double myelination forms through a mechanism involving displacement of an original myelinating Schwann cell by an interposed Schwann cell (see companion paper), we here provide evidence that in some instances the outer Schwann cell fails to retain any direct axonal contact, either with the axon centrally enclosed within the configuration or with any neighbouring axon. In contrast to the rat, delicate cytoplasmic processes often extended from the lateral extremes of outer Schwann cells. However, again no evidence for axonal contact was found, and similar processes also extended from the paranodal region of some singly myelinated non-displaced Schwann cells. Without exception the outer myelin sheath remained structurally intact, and characteristically underwent a series of conformational changes (progressive infolding of the paranodes and new areas of myelin compaction) which infer a continuing capacity of the outer Schwann cell to translocate myelin-specific components in a co-ordinated manner. A basal lamina was always present on the 'abaxonal' plasma membrane of the outer cell, but not on the 'adaxonal' surface except in areas involved in infolding, thus retaining the polarity which existed at the time of displacement from the axon. At single cross-sectional levels through the SCG, up to approximately 4% of myelinated axons were involved in double myelination. Double myelination was not detected in the sciatic nerve or in the paravertebral ganglia, thus indicating a predilection for the SCG as a site of development of these configurations. Though not challenging the role of the axon in initiating the formation of myelin, these data indicate that in this tissue myelin maintenance does not require direct contact between axonal and Schwann cell plasma membranes.

Associated central and peripheral demyelination: an electrophysiological study

A case is reported in which retrobulbar neuritis preceded Guillain-Barré syndrome by 4 weeks. The visual evoked potential latencies were prolonged. After peripheral nervous system signs had cleared, median and peroneal somatosensory evoked potentials showed prolonged cervical N13, scalp N20 and L3-scalp conduction times.

Demyelinating optic neuropathy with Miller-Fisher syndrome. The case for overlap syndromes with central and peripheral demyelination

The syndrome of ataxia, areflexia and ophthalmoplegia, or Miller-Fisher syndrome, has been considered to be a variant of Guillain-Barré syndrome with pathology restricted to the peripheral nervous system. A patient with Miller-Fisher syndrome and bilateral demyelinating optic neuropathy suggesting associated central nervous system pathology is presented. Clinical and experimental evidence regarding the association of central and peripheral nervous system demyelination is reviewed.

Peripheral nervous system lesions in experimental allergic encephalomyelitis. Ultrastructural distribution of T cells and Ia-antigen

The distribution of T cells and Ia-antigen in peripheral nervous system (PNS) lesions of experimental allergic encephalomyelitis was studied by light- and electron-microscopic immunocytochemical techniques. Sprague Dawley rats, sensitized with guinea pig spinal cord tissue, developed a biphasic disease with acute inflammatory and chronic inflammatory demyelinating lesions in the PNS. In both the acute non-demyelinating and the chronic demyelinating disease inflammatory infiltrates were composed of T cells and Ia-positive monocytes/macrophages. Dependent upon the stage of the disease a variable percentage of T-lymphocytes carried the Ox 8 antigen (suppressor/cytotoxic cells). In demyelinating lesions no evidence for an interaction of T cells with myelin or Schwann cells was observed, thus arguing against a direct T-cell cytotoxicity in demyelination. The whole sequence of myelin destruction and digestion was performed by W3/13-, Ia+ mononuclear cells with ultrastructural features of monocytes/macrophages. In contrast to the acute inflammatory stage of the disease, high titers of anti-myelin antibodies were present in sera of affected animals sampled during the chronic inflammatory demyelinating stage. The sera from the latter animals also showed pronounced in vivo demyelinating activity when transferred into the cerebrospinal fluid (CSF) of normal recipient rats. It is thus suggested that demyelination in this model is induced by a co-operation of cell-mediated and humoral immune mechanisms. We did not find evidence for Ia-antigen expression on local elements of the PNS (Schwann cells, axons, or endothelial cells).

Ia antigens in the normal rat nervous system and in lesions of experimental allergic encephalomyelitis

The distribution of the class II major histocompatibility (Ia) antigens has been studied in the normal nervous system and in acute lesions of experimental allergic encephalomyelitis (EAE). EAE was induced in Lewis rats with guinea pig spinal cord in Freund's complete adjuvant. Frozen sections from cord, including the roots and ganglia, were stained for Ia antigens, and some sections were also stained for the hydrolytic enzyme acid phosphatase. In the normal CNS and PNS, there were a few vessel-associated cells or small leukocyte-like cells which expressed Ia antigens. No cells were found which expressed both Ia and acid phosphatase [the phenotype used to describe the activated macrophage group of antigen presenting cells (APCs)]. In EAE, Ia positive cells increased in number prior to the detection of clinical signs. Some of these Ia-positive cells were thought to be astrocytes rather than inflammatory cells. At the height of the disease process large numbers of cells in the EAE lesions were Ia-positive. Among these infiltrating cells were some large acid phosphatase-positive cells which also expressed Ia antigens. These double-positive cells appeared to be APCs in the form of activated macrophages, cells known to be involved in the demyelinating processes of EAE. Our results show that some vascular and vessel-associated cells in the normal nervous system express Ia antigens. We suggest that these and other Ia-positive cells in acute EAE lesions may have a role in antigen presentation.

Acute polyradiculoneuritis associated with demyelinated plaques in the central nervous system: report of a case

A report is given of a woman who developed acute idiopathic polyradiculoneuritis and was found at necropsy 9 weeks later to have in addition multiple recent demyelinated lesions in the central nervous system (CNS), resembling those of multiple sclerosis (MS). The possibility that in such a case there might be an immunological reaction against one or more components of myelin common to the CNS and PNS has to be considered.

Multiple sclerosis and hypertrophic demyelinating peripheral neuropathy

A combination of multiple sclerosis (MS) and hypertrophic demyelinating neuropathy has been reported in a few autopsy studies. We are reporting a unique case of such a combination, which was proved by the sural nerve biopsy. A patient with classical MS on history and findings had areflexia and sensory abnormalities in stocking distribution. The nerve conduction study showed marked abnormalities indicative of demyelinating neuropathy, and sural nerve biopsy was typical of hypertrophic demyelinating neuropathy.

Nerve fibres in spinal cord impact injuries. Part 1. Changes in the myelin sheath during the initial 5 weeks

The spinal cords of cats were subjected to an impact injury using a "weight dropping" technique and sequential changes in the sheaths of non-degenerate myelinated fibres studied over a 3-week period. By 1 1/2 h after impact fibres showed retraction of some lateral loops from one paranode. The extent and severity of this change increased over the first week so that partial and full thickness demyelination were seen frequently. Partial demyelination most commonly resulted from the internodal termination of the innermost lamellae at an internodal location often associated with a Schmidt-Lantermann incisure. Remyelination by both Schwann cells and oligodendroglia occurred at the end of the second week. Oligodendroglial myelin showed many features of immaturity, similar to those found during development. It is suggested that the very earliest myelin damage is mechanical but is aggravated by other factor(s) one of which is probably ischaemia. Within the most severely injured areas there is death of oligodendroglia and any surviving axons are remyelinated principally by Schwann cells. In intermediate and minimally damaged areas of white matter oligodendroglial remyelination predominates.

Double myelination of axons in the sympathetic nervous system

Relationships between axons and Schwann cells in myelinated fibres of the superior cervical (sympathetic) ganglion have been examined in normal adult rats. In cross-sections through the ganglion up to 4% of myelinated fibres were focally encircled by an additional myelinating Schwann cell, forming regions termed 'double myelination'. In these regions and elsewhere in the ganglion, the structure of the inner fibre (axons and myelinating Schwann cell) conformed to the relationships expected on the basis of numerous previous investigations on normal peripheral nerve. However, the outer Schwann cell and myelin sheath, which formed an annulus around the inner fibre, was remarkable in that it apparently made no direct contact either with the centrally enclosed axons or with an neighbouring axon, yet appeared largely if not completely intact. In addition, the increasing frequency of double myelination in older animals and the rarity of myelin degeneration in the same ganglia indicate that the outer Schwann cell, and in particular its myelin sheath, persist for some period in an isolated form. Double myelination was not located in non-sympathetic peripheral nerve samples from the same animals. Double myelination may result from the displacement of one myelin internode by the interposition of another Schwann cell rendering the original Schwann cell redundant. There was no involvement of haematogenous cells as occurs in some demyelinating conditions. While some parallels may be found with previous studies, this would appear to be the first report of apparent survival of myelin in a Schwann cell not making, as far as could be determined in the present study, at least partial direct axonal contact. These observations on sympathetic nerve may provide a new perspective on axon-Schwann cell signalling.

Neuritogenic and chemical properties of guinea pig anterior and posterior root myelin

In relapsing experimental allergic encephalomyelitis, recurrent demyelination was found in the anterior roots and dorsal root ganglia with minimal involvement of the posterior roots. To determine whether this is an antigen-related phenomenon, the distribution, type and intensity of the lesions in the proximal PNS of guinea pigs immunized with anterior roots or myelin were compared to those of animals immunized with posterior roots or myelin. Homologous anterior roots were less neuritogenic than posterior roots or posterior root myelin. Thin layer chromatography of myelin samples from anterior and posterior roots, dorsal root ganglia and sciatic nerve revealed the presence of a sulfogalactoglycerolipid, tentatively identified as sulfated galactosylglyceride (SGG) in all but the posterior root myelin samples. Although the PNS lesions of relapsing experimental allergic encephalomyelitis appear to recapitulate the regional distribution of SGG, the reason why its presence in anterior roots myelin renders them less neuritogenic is at present not clear.

Observations on the effect of injection of lymphocytes from multiple sclerosis and Guillain-Barré syndrome in the rabbit eye model

The effect of 10 X 10(5) peripheral blood lymphocytes (PBL) obtained from patients with multiple sclerosis (MS), Guillain-Barré syndrome (GBS) and healthy controls was studied after injection into the rabbit eye. Infiltration of inflammatory cells, strikingly localized to myelinated strips, was obtained with PBL from some of the MS patients and controls, indicating the non-specificity of the phenomenon. PBL from 2 GBS patients gave the strongest infiltration. No effect was obtained with 10 X 10(4) PBL or CSF lymphocytes from MS patients, indicating that the number of lymphocytes is an essential factor in the induction of lesions.