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PubMed2005

Clinical course, pathological correlations, and outcome of biopsy proved inflammatory demyelinating disease.

BACKGROUND: A pathological classification has been developed of early active multiple sclerosis (MS) lesions that reveals four patterns of tissue injury: I-T cell/macrophage associated; II-antibody/complement associated; III-distal oligodendrogliopathy, and IV-oligodendrocyte degeneration in the periplaque white matter. Mechanisms of demyelination in early MS may differ among the subgroups. Previous studies on biopsied MS have lacked clinicopathological correlation and follow up. Critics argue that observations are not generalisable to prototypic MS. OBJECTIVE: To describe the clinicopathological characteristics of the MS Lesion Project biopsy cohort. METHODS: Clinical characteristics and disability of patients with pathologically confirmed inflammatory demyelinating disease (excluding ADEM) classified immunopathologically (n = 91) and patients from the Olmsted County MS prevalence cohort (n = 218) were determined. RESULTS: Most patients who underwent biopsy and had pathologically proved demyelinating disease ultimately developed definite (n = 70) or probable (n = 12) MS (median follow up 4.4 years). Most had a relapsing remitting course and 73% were ambulatory (EDSS < or =4) at last follow up. Nine patients remained classified as having an isolated demyelinating syndrome at last follow up. Patients with different immunopathological patterns had similar clinical characteristics. Although presenting symptoms and sex ratios differed, the clinical course in biopsy patients was similar to the prevalence cohort. Median EDSS was <4.0 in both cohorts when matched for disease duration, sex, and age. CONCLUSIONS: Most patients undergoing biopsy, who had pathologically confirmed demyelinating disease, were likely to develop MS and remain ambulatory after a median disease duration of 4.4 years. The immunopathological patterns lacked specific clinical correlations and were not related to the timing of the biopsy. These data suggest that pathogenic implications derived largely from MS biopsy studies may be extrapolated to the general MS population.

Adolescent↗
PubMed1999

Does the extent of axonal loss and demyelination from chronic lesions in multiple sclerosis correlate with the clinical subgroup?

OBJECTIVE: To determine non-invasively the relation between the degree of axonal loss and the extent of demyelination in chronic lesions visible on MRI in patients with different subgroups of clinically definite multiple sclerosis using (1)H magnetic resonance spectroscopy ((1)H MRS) and magnetisation transfer imaging (MT). Conventional MRI is unable to differentiate between the various pathological processes occurring in the multiple sclerosis lesion. There are, however, newer MR techniques which show promise in this respect. METHODS: (1)H MRS and MT were performed in 18 patients with clinically definite multiple sclerosis who had a wide range of disability and disease duration. RESULTS: A significant correlation was found between a reduction in the concentration of N-acetyl aspartate (NAA; an in vivo marker of axonal loss or dysfunction) and a reduction in MT ratio (a probable marker of demyelination) in patients who had entered the secondary progressive stage of the disease. Patients with minimal disability after a disease duration of greater than 10 years-so called benign multiple sclerosis-showed a relative preservation of NAA and MT. CONCLUSIONS: Because a reduction in MT seems to be a relative marker for demyelination and a reduction of NAA from chronic lesions is indicative of axonal loss, this study supports the hypothesis that demyelination and axonal loss occur in the same chronic multiple sclerosis lesions. In addition, the degree of axonal loss and demyelination correlates with clinical heterogeneity.

Aspartic Acid↗
PubMed2001

Demyelinating disorder of the central nervous system occurring in black South Africans.

OBJECTIVES: To investigate the nature and cause in eight black South African patients of a recurrent (multiphasic), remitting, and relapsing demyelinating disease of the CNS. METHODS: The clinical and laboratory investigations and radiological manifestations of these patients were documented. RESULTS: Each patient had two or more acute attacks of demyelinating disease affecting the CNS. The clinical presentations of the patients were predominantly those of multiphasic neuromyelitis optica (NMO). Brain MRI in these patients showed features consistent with those described for acute disseminated encephalomyelitis (ADEM), as well as lesions that are described in multiple sclerosis. There was involvement of the corpus callosum in addition to typical ADEM lesions. Laboratory investigations excluded all other known causes of multiphasic CNS demyelination. Oligoclonal antibodies were not detected in these patients at any time. The patients were all from a population with a low risk for MS (black South Africans). CONCLUSION: The patients described here represent a new phenotypic expression of a recurrent (multiphasic), steroid sensitive, inflammatory demyelinating disorder of the CNS occurring in black South Africans. The disorder is either a distinct inflammatory demyelinating disorder of the CNS of as yet unknown aetiology, or a varied form of MS (ADEM/NMO) occurring in a population with a low risk (where the genetic trait and environmental risk factors for MS do not exist) for MS.

Adult↗
PubMed2004

Cortical microinfarcts and demyelination significantly affect cognition in brain aging.

BACKGROUND AND PURPOSE: Microvascular lesions are common in brain aging, but their clinical impact is debated. Methodological problems such as the masking effect of concomitant pathologies may explain discrepancies among previous studies. To evaluate the cognitive consequences of such lesions, we prospectively investigated elderly individuals with various degrees of cognitive impairment but without significant neurofibrillary tangle pathology or macrovascular lesions. METHODS: This was a clinicopathological study of 45 elderly individuals. Cognitive status was assessed prospectively with the Clinical Dementia Rating (CDR) scale; neuropathological evaluation included Abeta-protein deposition staging and bilateral semiquantitative assessment of cortical microinfarcts, focal cortical and white matter glioses, and diffuse white matter and periventricular demyelination. RESULTS: In a univariate logistic regression model, cortical microinfarcts explained 36.1% of the variability in CDR; periventricular demyelination, 10.6%; and diffuse white matter demyelination, 4.6%. After controlling for age and Abeta-protein deposition, cortical microinfarcts were the best predictor of cognitive status (19.9% of CDR variability), whereas periventricular and diffuse white matter demyelination accounted for 9.7% and 5.4% of CDR variability, respectively. Altogether, these 3 types of microvascular lesions explained 27.9% of the clinical variability. Focal cortical and white matter glioses were not related to clinical outcome. CONCLUSIONS: Our data imply that cortical microinfarcts and both periventricular and deep white matter demyelination contribute significantly to the progression of cognitive deficits in brain aging. In contrast, the neuropathological evaluation of focal cortical and white matter gliosis has no clinical validity.

Aged↗
PubMed1998

Expression of the human histocompatibility leukocyte antigen DR3 transgene reduces the severity of demyelination in a murine model of multiple sclerosis.

The role of various MHC genes in determining the progression of multiple sclerosis (MS) remains controversial. The HLA-DR3 gene has been associated with benign relapsing MS in some genetic epidemiologic studies, but with disease progression in others. We induced demyelination in highly susceptible B10.M and B10.Q mice expressing the DR3 (HLA-DRB1*0301) transgene to determine directly the effects of a human transgene by infecting them with Theiler's murine encephalomyelitis virus (TMEV). DR3+ mice experienced a dramatic reduction in the extent and severity of demyelination compared with DR3- littermate controls, whereas anti-TMEV antibody titers, delayed-type hypersensitivity responses, and levels of infectious virus, virus antigen, and virus RNA were similar in both groups. To address a possible mechanism of how the human transgene is reducing virus-induced demyelination, we analyzed cytokine expression in the lesions and also determined whether B10.M mice can respond to peptides derived from the DR3 molecule. Intense staining for IFN-gamma and IL-4, T helper (TH) 1 and TH2 cytokines, respectively, was found in the lesions of TMEV-infected DR3- mice but not in the DR3+ transgenic mice at day 21 after infection. DR3 peptides elicited strong proliferative responses in B10.M mice but not in B10.M (DR3+) mice. These experiments are the first to demonstrate that a human class II DR gene can alter the severity of demyelination in an animal model of MS without influencing viral load. These experiments are consistent with a mechanism by which DR3 reduces demyelination by altering the cytokine expression in the lesions, possibly by deleting T cells involved in virus-induced pathology.

Animals↗
PubMed1997

Enhancement of central nervous system remyelination in immune and non-immune experimental models of demyelination.

Studies in both humans and experimental animals indicate that there is potential for full remyelination following CNS demyelination, but the factors that control the degree of myelin repair are unknown. In the Theiler's virus model of demyelination CNS remyelination can be promoted either by global immunosuppression or by selective immunoglobulin therapy. In this paper we discuss whether immunoglobulin-mediated remyelination is a characteristic of immune-mediated demyelination, or whether immunoglobulin-mediated remyelination also occurs in the toxic-traumatic model of lysolecithin-induced demyelination. Our data support the hypothesis that even in a non-primary immune model of demyelination, manipulating the immune system can be beneficial in myelin repair.

Animals↗
PubMed1999

Lesion development in Marburg's type of acute multiple sclerosis: from inflammation to demyelination.

We report a patient who suffered from acute inflammatory CNS demyelination and underwent two consecutive diagnostic stereotactic brain biopsies during the early disease course. The first lesion was drawn 33 days after the onset of disseminated neurological symptoms. Macrophages and T lymphocytes diffusely infiltrated small vessel walls and the white matter. mRNA for tumor necrosis factor alpha (TNFalpha) and inducible nitric oxide synthase (iNOS) was abundantly expressed. Myelin sheaths were entirely preserved. The second biopsy 76 days later showed confluent demyelinating lesions with a diffuse infiltration of macrophages that were positive for myelin debris, activation markers and TNFalpha and iNOS mRNA. IgG and C9neo deposits were found along myelin sheaths. The patient had received intravenous immunoglobulins (IVIG) prior to biopsy. Findings from this single patient affirm that demyelination follows the migration of inflammatory cells from the circulation into the white matter with subsequent inflammation and demyelination. Inflammation alone may be sufficient to cause significant clinical deficits without demyelination. Inflammatory mediators such as TNFalpha and NO are involved at very early stages in the pathogenetic process. IVIG treatment may lead to the deposition of immunoglobulins and to the activation of the complement cascade, but the clinical relevance of this particular finding remains uncertain.

Acute Disease↗
PubMed2006

Patterns and significance of concomitant central and peripheral inflammatory demyelination.

Inflammatory demyelinating diseases comprise a spectrum of disorders that affect central nervous system (CNS) and peripheral nervous system (PNS) myelin. Most individuals have demyelinating disease restricted to one or the other compartment but patients with concomitant CNS and PNS inflammatory inflammatory demyelinating processes have been reported not infrequently. In most such patients, involvement of either the CNS or the PNS predominates the clinical picture. Involvement of the other compartment is usually mild or subclinical with unclear prognostic and therapeutic implications. Similarly, while experimentally induced demyelinating disease in animal models is usually CNS or PNS predominant, varying degrees of pathology in the other system can occur depending on the species, type of immunogen, and genetic background of the immunized animal. When CNS and PNS demyelinating diseases occur concurrently, effective treatment for CNS disease can be safely combined with effective treatment for PNS disease.

Animals↗
PubMed2002

Predictors of short-term disease activity following a first clinical demyelinating event: analysis of the CHAMPS placebo group.

We evaluated 190 patients in the placebo group of the CHAMPS trial in order to assess factors associated with short-term dinical and brain magnetic resonance imaging (MRI) outcomes in patients with a first dinical demyelinating event involving the optic nerve, spinal cord, or brainstem/cerebellum, and subdinical demyelination on brain MRI. The two study outcomes were 1) development of clinically definite multiple sclerosis (CDMS) and 2) development of CDMS or two or more new or enlarging brain MRI T2 lesions. The presence of gadolinium (Gd)-enhancing lesions on the baseline scan was the only MRI characteristic associated with a higher risk of both the clinical and combined outcomes (p = 0.003 and < 0.001, respectively). The only demographic or clinical characteristic associated with an increased risk of these outcomes was younger age (p < 0.001 for both outcomes). The lowest risk subgroups we could define had a 30% risk of CDMS and a 65% risk of the combined clinical/MRI outcome. Our results indicate that all patients presenting with a first demyelinating event who also have brain MRI evidence of subclinical demyelination have at least a moderate risk of short-term disease activity. This finding provides support for initiating disease-modifying therapy at the time of the first demyelinating event in patients meetng the CHAMPS enrollment criteria.

Adult↗
PubMed1980

Multiple sclerosis: serum gamma globulin and demyelination in organ culture.

Multiple sclerosis (MS) sera frequently demyelinate organotypic central nervous system (CNS) tissue cultures. To elucidate the possible role of gamma globulins in this form of experimental demyelination we depleted MS sera of all gamma globulins by immunoabsorption and then compared their demyelinating activity with that of the unabsorbed sera. In only 2 out of 16 patients was some demyelinating activity detected in the gamma globulin fraction. In all patients, most of the demyelinating activity was not associated with gamma globulins. In gel filtration experiments, this non-gamma globulin activity was detected in a high-molecular-weight and in a low-molecular-weight fraction.

Animals↗
PubMed1990

Demyelinating changes in sural nerve biopsy of patients with HTLV-I-associated myelopathy.

We describe the sural nerve pathology in 3 patients with HTLV-I-associated myelopathy (HAM). These patients showed remarkable symptoms of myelopathy and had high HTLV-I titers in the serum and CSF. The common pathologic findings in the sural nerves were as follows: slightly decreased density in myelinated fibers (6,567/mm2, 6,488/mm2, and 7,159/mm2; control 9,999 +/- 3,446/mm2), frequent occurrence of demyelinated and remyelinated fibers, and many degenerating fibers with globule-like myelin changes. Teased-fiber analysis indicated the globule-like changes (Dyck's G change) to be accompanied by the formation of adjacent demyelinated segments. The globules result from slowly repetitive degenerative changes of myelin and are considered to be a form of demyelination. However, they have seldom been found in other demyelinating neuropathies, indicating the demyelination process with globule formation in HAM to be rather specific for this disease.

Axons↗
PubMed1988

[Myelination, demyelination and re-myelination in the central nervous system].

The myelin sheaths that surround axons in the CNS are made and maintained by oligodendrocytes. These glial cells can form variable numbers of myelin segments (internodules): from 1 to 200 so that when one oligodendrocyte is destroyed with preservation of the axon, many internodules can be lost, constituting a demyelinating process. As a consequence of the destruction of myelin and sheath cells a rapid and abundant cell response takes place. The response is made up by resident (microglia) and haematogenous phagocytes which phagocytose myelin and cellular debris leaving the axons demyelinated. Demyelinated axons may either stay demyelinated and clumped together or they may be separated by astrocytic processes, yet they can be remyelinated. The occurrence of remyelination depends upon the intensity and time of exposition to the demyelinating agent. Remyelination in the CNS with complete restoration of conduction may be made by oligodendrocytes or Schwann cells which invade the CNS when astrocytes are destroyed.

Animals↗
PubMed1989

Induction of hyperacute brain inflammation and demyelination by activated encephalitogenic T cells and a monoclonal antibody specific for a myelin/oligodendrocyte glycoprotein.

CNS demyelinating inflammatory disease can be a multifactorial process mediated by cellular and antibody-mediated immune processes. Myelin basic protein (MBP)-specific T cells and pathogenic 8-18C5 antibody, specific for a myelin/oligodendrocyte glycoprotein (MOG), a minor component of CNS white matter, can coexist in rats without triggering disease. However, transfer of activated MBP-specific T-cells followed by the injection of 8-18C5 antibody resulted in hyperacute disease progression and CNS demyelination. Transfer of activated T cells specific for an irrelevant antigen or transfer of activated but irradiated encephalitogenic T cells did not induce disease in the presence of 8-18C5 antibody. When needle lesions were induced in brains of 8-18C5 antibody treated rats, no enhancement of demyelination was seen around the needle track. Thus, accessibility of the brain parenchyma to 8-18C5 antibody was not sufficient to induce local demyelination. Therefore, it appears that activated encephalitogenic T cells are involved in initiating the 8-18C5 antibody-mediated demyelinating process.

Animals↗
PubMed2007

Expansile, enhancing cervical cord lesion with an associated syrinx secondary to demyelination. Case report and review of the literature.

The authors describe the case of a patient with an enhancing, intramedullary cervical spinal cord lesion and associated syrinx. Biopsy sampling of the cervical lesion was performed, and the histological findings were consistent with a demyelinating process supporting the diagnosis of multiple sclerosis (MS). Syrinx formation associated with demyelinating disease has only been described in isolated cases, almost exclusively in Japanese patients with MS. A 22-year-old woman of Caribbean descent presented with a subacute, progressive myelopathy including symptoms of pain and weakness in all extremities, bladder incontinence, and the inability to ambulate. Magnetic resonance imaging of the brain and spinal cord demonstrated an enlarged cervical cord with enhancement and central cavitation consistent with a syrinx. The patient underwent a C3-7 laminoplasty and placement of a dural graft for cord decompression as well as fenestration of the central syrinx. Biopsy sampling of the lesion was performed, and the histopathological analysis, in conjunction with subsequent laboratory and diagnostic testing, supported the diagnosis of demyelinating disease. After treatment with a course of high-dose dexamethasone and inpatient rehabilitation therapy, the patient demonstrated significant clinical improvement. Spinal cord involvement is not uncommon in patients with demyelinating disease; however, enhancing lesions associated with extensive tissue loss and syrinx formation have rarely been reported. For the consulting neurological surgeon, demyelinating disease should be included in the differential diagnosis of such lesions given the level of complexity and risk to the patient associated with open biopsy of the spinal cord.

Adult↗
PubMed2002

Bystander CD8 T cell-mediated demyelination after viral infection of the central nervous system.

Multiple sclerosis, a chronic inflammatory disease of the CNS, is characterized by immune-mediated demyelination. Many patients have a remitting-relapsing course of disease with exacerbations often following unrelated microbial illnesses. The relationship between the two events remains obscure. One possibility is that T cells specific for the inciting microbial pathogen are able to effect demyelination at a site of ongoing inflammation within the CNS. This possibility was examined in mice infected with mouse hepatitis virus, a well-described model of virus-induced demyelination. Using transgenic TCR/recombination activation gene 2(-/-) mice with only non-mouse hepatitis virus-specific T cells, we show that CD8 T cells are able to cause demyelination in the absence of cognate Ag in the CNS, but only if specifically activated. These findings demonstrate a novel mechanism for immune-mediated neuropathology and show that activated CD8 T cells may serve as important mediators of bystander demyelination during times of infection, including in patients with multiple sclerosis.

Animals↗
PubMed1999

Inflammatory CNS demyelination: histopathologic correlation with in vivo quantitative proton MR spectroscopy.

BACKGROUND AND PURPOSE: The mechanisms behind the demyelination that is characteristic of multiple sclerosis (MS) are still poorly understood. The purpose of this study was to compare immunopathologic findings in demyelinating lesions of three patients with in vivo assessments obtained by quantitative proton MR spectroscopy (MRS). METHODS: Between four and seven stereotactic needle brain biopsies were performed in three young adults with diagnostically equivocal findings for MS. Axonal density, gliosis, blood brain-barrier breakdown, and demyelinating activity of lesions were determined. Combined MR/MRS studies were performed (T1-weighted fast low-angle shot and single-voxel stimulated-echo acquisition mode), and absolute metabolite levels were obtained with a user-independent fitting routine. Metabolite control values were obtained from a group of age-matched healthy volunteers (n = 40, age range, 20-25 years old). Alterations of metabolite levels of control subjects were considered significant when exceeding two standard deviations. RESULTS: There were parallel decreases of N-acetylaspartate (21%-82%) and reductions of axonal density (44%-74%) in demyelinating plaques. Concomitant increases of choline (75%-152%) and myo-inositol (84%-160%) corresponded to glial proliferation. Elevated lactate was associated with inflammation. CONCLUSION: The present data suggest that in vivo MRS indicates key pathologic features of demyelinating lesions.

Adult↗
PubMed2000

[The first episode of central nervous system demyelinization and hepatitis B virus vaccination].

BACKGROUND: Central nervous system (CNS) demyelinating episodes have been described following numerous vaccines but there is no definite conclusion about a causal relationship. Recently, in France, in the context of an Expanded Program on Immunization, several cases of CNS demyelination have been observed following injection of recombinant hepatitis B (HB) vaccine, leading to great concern. METHODS: We performed a hospital-based case-control study of 121 patients with a first episode of CNS demyelination occuring between July 1993 and December 1995 and 121 age and sex matched controls seen in the same period. Data on vaccinations history of cases and controls were collected by a postal questionnaire and confirmed by a phone interview. RESULTS: Adjusted odds ratio (OR) obtained from conditional logistic regression between a first episode of CNS demyelination and any vaccination were equal to 1.4 (95 p. 100 CI 0. 5-4.3) for an exposure within the 60 previous days and 2.1 (95 p. 100 CI 0.7-6.0) for an exposure within the 61-180 previous days. Similar results were found for HB vaccine exposure within the 60 previous days (adjusted OR=1.7, 95 p. 100 CI 0.5-6.3) or within the 61 to 180 previous days (adjusted OR= 1.5, 95 p. 100 CI 0.5-5.3). CONCLUSION: These findings did not permit to exclude confidently an association between HB vaccine and the occurrence of a first CNS demyelinating episode.

Adult↗
PubMed2000

[Central nervous system demyelinating disease following hepatitis B vaccination with GenHevac B. Review of ten years of spontaneous notifications (1989-1998)].

OBJECTIVES: To describe and analyze spontaneous reports of central nervous system (CNS) demyelinating disease including multiple sclerosis, following vaccination with GenHevac B vaccine, from 1989 to December 31, 1998. METHODS: Descriptive analysis of adverse event reports in the vaccinated population, including the number of cases of CNS demyelinating disease, their frequencies, their dates of onset in relation to dates of report and their distribution according to age, sex and the number of injections. A Kaplan-Meier curve was used to analyze the time period between the last dose of vaccine and the onset of CNS demyelinating disease. RESULTS: Overall, 187 cases of CNS demyelinating disease were spontaneously reported, (0.54 reports per 100,000 doses of GenHevac B distributed). The average time period between the occurring date of onset of the disease and its subsequent report was 24 months. The average age of onset was 31.7 years old and 73% of cases were women. The time between the last dose of vaccine and the onset of disease was regularly distributed from 1 day to 5 years (median: 60 days). CONCLUSION: These results, together with available clinical, epidemiological data regarding multiple sclerosis, do not suggest a causal relationship between CNS demyelinating disease and vaccination with GenHevac B.

Adult↗