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PubMed2002

Comparison of electrodiagnostic criteria for demyelination in patients with chronic inflammatory demyelinating polyneuropathy (CIDP).

This study compared sensitivity, specificity, positive and negative likelihood ratios (LR) of four previously published sets of electrodiagnostic criteria for demyelination in 64 patients whose history and physical examination indicated that chronic inflammatory demyelinating polyneuropathy was a possible diagnosis. Sensitivity of the sets of criteria ranged from 56-70 % and specificity from 85-98 %. Positive LRs ranged from 4.67-28 and negative LR's from 0.35-0.45. The results showed that one set of electrodiagnostic criteria was considerably more helpful than the other three in establishing the diagnosis CIDP. If, however, the test results of the sets were not consistent with demyelination, the effect of the negative test results on the probability of the diagnosis CIDP was similar for all four sets.

Adolescent↗
PubMed1991

Chronic multifocal demyelinating neuropathy associated with central nervous system demyelination.

We have carried out a long-term study of lesions found in a man who had a demyelinating disease of both central and peripheral nervous systems. During the 10 years of his clinical course, he suffered from optic neuritis, multifocal myelitis, and chronic multifocal demyelinating neuropathy, with persistent conduction block. Our study revealed that both central and peripheral nervous system demyelination occurred repeatedly and simultaneously.

Adult↗
PubMed1987

Cyclosporine enhances virally induced T-cell-mediated demyelination. The effect of cyclosporine on a demyelinating virus infection.

Semliki Forest virus infection of adult mice results in a demyelinating meningoencephalomyelitis. Demyelination does not result from direct viral damage but from the activity of T lymphocytes. We have studied the effect of the immunosuppressant cyclosporine (Cs) on the outcome of this infection. Cs had no effect when given 5 days after the infection, and little effect when given 4 h after infection. When the Cs was given 48 h before infection there was a prolongation of the blood and brain virus titres, and a reduction in some mice of serum IgG anti-viral antibody synthesis, but an increase in the severity of the CNS inflammatory response and the demyelination. Consideration of these findings along with measurement of Cs levels in the serum and cerebrospinal fluid suggests that this drug does not cross the blood brain barrier.

Animals↗
PubMed2005

Axonal injury in the cerebral normal-appearing white matter of patients with multiple sclerosis is related to concurrent demyelination in lesions but not to concurrent demyelination in normal-appearing white matter.

We assessed axonal injury and demyelination in the cerebral normal-appearing white matter (NAWM) of MS patients in a pilot study using proton magnetic resonance spectroscopic imaging and quantitative magnetization transfer (MT) imaging. Resonance intensities of N-acetylaspartate (NAA) relative to creatine (Cr) were measured in a large central brain volume. NAA/Cr in NAWM was estimated by regression of the NAA/Cr in each voxel against white matter fraction and extrapolation to a white matter fraction of 1. The fractional size of the semi-solid pool (F) was obtained from the binary spin bath model of MT by computing the model parameters from multiple MT-weighted and relaxometry acquisitions. F in NAWM was significantly smaller in the patients [0.109 (0.009)] relative to controls [0.123 (0.007), P = 0.011], but did not differ between RR [0.1085] and SP [0.1087] patients [P > 0.99]. NAA/Cr and F in the NAWM were not correlated (r = 0.16, P > 0.7), mainly due to a lack of variation in F among patients. This may indicate a floor to the extent of myelin pathology that can occur in NAWM before a lesion appears, or that axonal damage is not strictly related to demyelination. The correlation between NAWM NAA/Cr and T2w lesion volume was not significant (P > 0.1). However, dividing the lesion volumes by the mean F in T2w lesions resulted in a quantity that correlated well with NAWM NAA/Cr (r = -0.78, P = 0.038), possibly reflecting the association of Wallerian degeneration in the NAWM with axonal transection associated with demyelination within lesions.

Adult↗
PubMed1987

Chronic demyelinating peripheral neuropathy associated with multifocal central nervous system demyelination.

A series of 6 cases is described in which a chronic demyelinating neuropathy was associated with a relapsing multifocal CNS disorder, the clinical features of which resembled multiple sclerosis. Multifocal CNS lesions were demonstrated by CT and MR imaging and the presence of CNS demyelination was indicated by prolonged central conduction times. These cases are discussed in relation to the occurrence of combined peripheral and central demyelination in chronic relapsing experimental allergic encephalomyelitis and neuritis.

Action Potentials↗
PubMedDate not supplied

Demyelination induced in mice by avirulent Semliki Forest virus. II. An ultrastructural study of focal demyelination in the brain.

Four-week-old mice were infected intraperitoneally with an avirulent strain A7(74) of Semliki Forest virus (SFV) and killed at 4, 10, 15, 21 and 29 days after inoculation. Focal demyelinating lesions were present by 10 days. These were usually accompanied by a mononuclear infiltrate which included lymphocytes possessing characteristic cytoplasmic projections. These latter extended deep into the cytoplasm of adjacent cells, which were usually astrocytes and macrophages. Other features of the focal lesions were expansion of the extracellular space and demyelination which appeared to be fragmentation or lysis rather than stripping of myelin by macrophages. Although healing occurred in some mice after 4 weeks, acute lesions were still found in others of the same age. It was concluded that the demyelination probably had an immunological basis, and interaction between elements of the immune system and glial cells was a factor which inhibited orderly remyelination of the relatively mild lesions resulting from this infection.

Animals↗
PubMed1991

[On the mechanisms and diagnosis of conduction disturbances due to demyelination with special reference to multifocal demyelinating neuropathy (Lewis-Sumner)].

Multifocal demyelinating neuropathy with persistent conduction block can mimic motor neuron disease, but is potentially reversible. Its diagnosis rests upon electrophysiological demonstration of focal conduction block at multiple sites. Conduction block is the most important mechanism causing clinical symptoms in peripheral nerve demyelination. On the other hand, conduction slowing is not always associated with clinical symptoms. In 2 out of 9 patients with multifocal demyelinating motor neuropathy, MRI showed focal swelling of the nerve at the site of conduction block. Both of them had elevated titers of anti-GM1 antibodies. In one, we biopsied a portion of the medial pectoral nerve, which was adjacent to the focal swelling, at surgical exploration. Pathological findings included very thin myelin associated with large diameter fibers and small onion bulb formation, suggesting that remyelinative process is abortive in this disease leading to persistent conduction block. Anti-GM1 antibodies bound to the denuded axoplasmic membrane may interfere with the process by masking the cell surface markers. The reason why the sensory fibers are spared is unclear, but it may be possible that GM1 in sensory axons have less affinity to the antibody than that in motor fibers.

Adolescent↗
PubMed1999

Combined peripheral nerve and central nervous system demyelination in a patient with chronic inflammatory demyelinating polyneuropathy.

We report the case of a 49-year-old woman suffering combined central and peripheral demyelination, with serial magnetic resonance images scans illustrating the development of central demyelination in a patient with established chronic inflammatory demyelinating polyneuropathy. This is the sixth patient with this rare overlap syndrome reported to date. We review the available literature and argue that an inherited predisposition to both diseases is the most likely explanation for its occurrence. Copyright 1999 Harcourt Publishers Ltd.

Journal Article↗
PubMed2000

Passive transfer of demyelination by serum or IgG from chronic inflammatory demyelinating polyneuropathy patients.

Chronic inflammatory demyelinating polyneuropathy (CIDP) is regarded as an autoimmune disorder, but no clearly defined autoimmune mechanism has been described. Although most patients respond to plasma exchange, no convincing role for autoantibodies has yet been demonstrated. In this study, we have successfully passively transferred disease using sera and purified IgG from 4 of 12 patients responsive to plasma exchange by bypassing the blood-nerve barrier by intraneural injection or opening it by activated T cells. The sera from CIDP patients or purified IgG produced marked conduction block and demyelination, but normal sera or IgG or that from patients with multiple sclerosis or other neuropathies did not. These observations strongly support an important role for anti-myelin/Schwann cell autoantibodies in the pathogenesis of CIDP at least in some patients.

Action Potentials↗
PubMed2000

Impact of plasma exchange on indices of demyelination in chronic inflammatory demyelinating polyradiculoneuropathy.

We studied the impact of plasma exchange (PE) on indices of primary demyelination in patients of the Canadian multicenter trial of PE in chronic inflammatory demyelinating polyneuropathy (CIDP). Individual motor nerves (median, ulnar, peroneal, tibial) were studied: distal motor latencies (DMLs), proximal and distal compound muscle action potential (M-wave) amplitudes, negative peak areas and durations, and motor conduction velocities (CVs). Proximal M-wave amplitudes in individual motor territories, particularly in the ulnar nerve (from below elbow, above elbow, and axillary stimulating sites) demonstrated significant improvement with PE, but not sham exchange. Proximal ulnar M-wave areas also had significant improvement with PE. Trends toward improvement of individual nerve motor CVs, M-wave durations, and DMLs did not achieve statistical significance. Proximal M-wave amplitudes, particularly in the ulnar motor territory, and proximal M-wave areas (providing a measure of conduction block) were the most sensitive indices of improvement conferred by PE in CIDP. In individual patients, these indices may help judge the efficacy of therapy.

Action Potentials↗
PubMed1987

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.

Aged↗
PubMed1992

Are CSF or serum ganglioside antibodies related to peripheral nerve demyelination in neuroborreliosis, Guillain-Barré syndrome, or chronic inflammatory demyelinating polyradiculoneuropathy?

Cerebrospinal fluid (CSF) and serum IgG and IgM antibodies to seven gangliosides were determined in patients with neuroborreliosis (NB) (n = 20), Guillain-Barré syndrome (GBS) (n = 13), and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) (n = 10). The incidence of elevated antibodies was highest in NB and lowest in CIDP. Correlation between CSF and serum antibodies was only observed for IgG antibodies to GM1, GD1b and GT1b in GBS. The strong IgM antibody reactivity to gangliosides in the CSF of NB patients may be involved in the variety of neurological disorders attributed to Borrelia burgdorferi infection. Since one CIDP and three GBS patients had serologic evidence of prior or concurrent borrelia infection, this infection may belong to the infections that can trigger GBS or CIDP. The lack of specific ganglioside antibody patterns in these four patients suggests that ganglioside antibodies are not the link between Borrelia burgdorferi infection and the demyelination of peripheral nerves in GBS and CIDP.

Adult↗
PubMed1995

Increased frequencies of HPRT mutant T lymphocytes in patients with Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy: further evidence for a role of T cells in the etiopathogenesis of peripheral demyelinating diseases.

We have used the HPRT mutant clonal assay to determine the frequency of mutant T lymphocytes (FMC), as a measure of recent T cell stimulation, in the blood of patients with Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP). We found that, compared to healthy controls, the FMC in patients with GBS (16) and CIDP (10) was significantly increased in the progressive phase of the neuropathy. FMC returned to normal values during recovery, suggesting a relationship between FMC and disease activity. No correlation was found between FMC values and motor deficit or severity of the neuropathy. The FMC of the GBS patients with a history of infection before onset of neurological symptoms or with insufficient respiration was not significantly different from the other GBS patients. Immunophenotypic analysis showed that the fraction of CD8+ HPRT mutant T cell clones was significantly increased in GBS patients (48%) compared to healthy controls (3%) or CIDP patients (4.5%). Our results are compatible with the notion that T cells are involved in the pathogenesis of demyelinating inflammatory neuropathies.

Adolescent↗
PubMed2005

Chronic inflammatory demyelinating polyneuropathy and other immune-mediated demyelinating neuropathies.

The identification of specific disorders caused by immune-mediated attack on Schwann cells and myelin have both improved and confused our understanding and classification of chronic inflammatory and immune-mediated neuropathies. Some investigators consider all neuropathies that respond to immunosuppressive treatment as chronic inflammatory demyelinating polyneuropathy (CIDP), regardless of whether there is evidence for demyelination. Other investigators rely on a very strict definition of CIDP and do not include variations. The goal of this article is to clarify the spectrum of these disorders and provide a logical classification scheme that has clinical utility and yet allows for new information that might distinguish new variations. Therapeutic strategies are also discussed.

Ataxia↗
PubMed1988

Absence of antimyelin antibodies and serum demyelinating factors in most patients with chronic inflammatory demyelinating polyradiculoneuropathy.

Patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) often respond to plasma exchange. One explanation for this is that circulating factors, such as antibodies or toxic factors, are removed from the serum. We studied CIDP nerves and CIDP sera for the presence of antibodies to myelin, Schwann cells and galactocerebroside, using immunofluorescence and enzyme-linked immunosorbent assays. On 1 of 28 CIDP nerve biopsies there was evidence of an IgG antibody bound to myelin. One of 57 CIDP sera had evidence of an antimyelin antibody, compared with 12 of 68 Guillain-Barré syndrome sera. We failed to find evidence of antibodies to Schwann cells or galactocerebroside in CIDP. The serum from only 1 of 11 patients showed demyelinating activity after direct intraneural injection. Thus these techniques do not demonstrate the presence of humoral factors to the tested antigens in the majority of CIDP patients. However, more sensitive methods may demonstrate antibodies to these antigens. Alternatively, CIDP may be associated with antibodies or factors toxic to other antigens, or else the response to plasma exchange may not be due to removal of a humoral factor.

Autoantibodies↗
PubMed1985

Alpha-1 antitrypsin phenotypes in demyelinating disease: an association between demyelinating disease and the allele PiM3.

Alpha-1 Antitrypsin, the major circulating protease inhibitor, has more than thirty alleles that can be identified by electrophoresis. In addition to its role as a protease inhibitor, alpha-1 antitrypsin may regulate the immune response. As there is evidence that both the inflammatory polyneuropathies and multiple sclerosis have an immune basis, and that genetic factors influence susceptibility, we have determined the alpha-1 antitrypsin phenotypes (protease inhibitor types) of 63 patients with Guillain-Barré syndrome, 52 patients with chronic inflammatory demyelinating polyneuropathy, and 178 patients with multiple sclerosis. In all 3 groups there was a significant increase in the proportion of patients with the protease inhibitor type M3 allele.

Alleles↗
PubMed1982

In vivo and in vitro models of demyelinating disease: endogenous factors influencing demyelinating disease caused by mouse hepatitis virus in rats and mice.

Intracerebral inoculation of JHM virus (JHMV), the neuropathic strain of mouse hepatitis virus, into Wistar Furth, Wistar Lewis, and Fischer 344 rats at various ages indicated that Wistar Furth rats are more susceptible to the virus than are the other strains. Fischer 344 and Wistar Lewis rats were more resistant to inoculation at 2 and 5 days of age and completely resistant by 10 days of age. In contrast, Wistar Furth rats which were very susceptible at both 2 and 5 days of age remained susceptible until 21 days of age. Intracerebral challenge of an F1 cross between Wistar Furth and Wistar Lewis rats at 10 days of age indicated that resistance to JHMV infection is dominant. Cyclophosphamide treatment 28 days after intracerebral inoculation exacerbated an inapparent infection, leading to paralysis in eight of nine and death in six of nine Wistar Furth test rats. In such immunosuppressed animals, grey- and white-matter lesions were noted throughout the central nervous system, in contrast to the purely demyelinating lesions noted previously. Since rats, unlike mice, were not susceptible to disease after intracerebral injection with the serorelated viscerotropic strain MHV-3, we wished to extend our understanding of the neurological disease process elicited by the two viruses in rodents. For this reason, various mouse strains, including some with recognized immunodeficiencies, were challenged by different routes of inoculation. Intraperitoneal infection of nude and beige mice with JHMV indicated that lack of natural killer cell functions does not markedly enhance the susceptibility to virus, whereas T-cell activity appears to be essential for resisting infection. JHMV and MHV-3 replication in peritoneal macrophages from highly resistant A/J mice was reduced in comparison with that noted in macrophages from susceptible C57BL6/J mice. An initial intraperitoneal inoculation of JHMV was able to protect C57BL6/J mice against fatal intracerebral challenge within 3 days, whereas A/J mice remained susceptible beyond day 3. The protective effect did not appear to result from increased levels of circulating interferon, preceded elevation in serum JHMV-neutralizing antibody titers, and persisted for at least several weeks after intraperitoneal inoculation. Based on the combined studies described here and on previous work by us and others, it appears that the factors influencing the outcome of coronavirus disease in rodents are age at inoculation, route of challenge, genetic constitution of the virus and host, and competence of the immune system, particularly cellular immunity involving T-cells.

Aging↗