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PubMed2000

Pathogenic immunity in Theiler's virus-induced demyelinating disease: a viral model for multiple sclerosis.

Multiple sclerosis involves inflammatory immune responses in the central nervous system (CNS) and is considered as an autoimmune disease potentially associated with viral infection. The majority of experimental models rely heavily on the autoimmune components since similar diseases can be induced following immunization with various myelin antigens. A very attractive alternative model is the Theiler's murine encephalomyelitis virus-induced demyelinating disease. This disease is primarily a CD4+ T cell-mediated, inflammatory demyelinating disease induced following viral infection. Virus-specific inflammatory Th1 cell responses, rather than cytotoxic T lymphocyte response, play a critical role in the pathogenic immune responses. The major pathogenic epitopes have been identified and these are correlated with a Th1 type response to the epitopes following viral infection. In addition, the initial virus-specific immune response is followed by the autoimmune responses to myelin antigens. Assessment of cytokines produced locally in the CNS during the course of disease suggests involvement of inflammatory cytokines in the disease. Furthermore, the manipulation of inflammatory cytokine levels by administration of either recombinant cytokines or antibodies to the cytokines strongly influences the induction and/or progression of disease, supporting the importance of these inflammatory cytokines in this virus-induced demyelinating disease.

CD4-Positive T-Lymphocytes↗

PubMedDate not supplied

Diabetic polyneuropathy. Axonal or demyelinating?

Diabetic polyneuropathy is the most common subgroup of diabetic neuropathy, but its nature is controversial as it might be demyelinating and/or axonal. We have tried to determine whether diabetic polyneuropathy is electrophysiologically axonal, demyelinating, or both. We have studied the sural and peroneal nerves and the electromyographies of leg muscles in 50 healthy subjects (average age 67.2 years, range 45 to 84 years), in 50 diabetic patients (average age 66.34 years, range 44 to 82 years) showing no symptoms and/or signs of polyneuropathy (DP1), and in 50 diabetic patients (average age 67.10 years, range 49 to 87 years) showing symptoms and/or signs of polyneuropathy (DP2). The amplitude (AMP) of sural and peroneal nerves in healthy and DP1 subjects was similar. Conduction velocity (CV) of sural and peroneal nerves was slower in DP1 subjects than in healthy subjects. DP2 subjects showed AMP and CV values significantly lower than those in DP1 subjects, and signs of acute and chronic denervation/reinervation were found in the leg muscles. We believe that this result indicates that diabetic patients have two types of polyneuropathies: a demyelinating disease that could appear in diabetic patients with and without symptoms of polyneuropathy, and an axonal loss that is responsible for most of the symptoms.

Aged↗

PubMed1975

Primary demyelination in Theiler's virus infection. An ultrastructural study.

Theiler's virus infection in SJL/J mice was studied ultrastructurally at subsequent intervals after intracerebral inoculation. Extensive spinal cord lesions consisting of leptomeningeal and white matter mononuclear cell infiltrates with concomitant primary demylination were seen by 15 days. Stripping of myelin lamellae by invading mononuclear cell processes and vesicular disruption of myelin were demonstrated to be the patterns of myelin breakdown. Oligodendrocytes in the vicinity of demyelinating lesions never showed degenerative changes, and viral inclusions could not be found in any cells in the central nervous system. Remyelinating axons, first detected 21 days after infections, were more frequently seen in the late phase of the disease when conspicuous gliosis was also present. Active demyelination could still be observed as late as one year after infection at which time inflammation was decreased. However, plasma cells were relatively more numerous at later times after infection. These ultrastructural findings are similar to experimental allergic encephalomyelitis, and suggest an immune-mediated mechanism of demyelination in Theiler's virus infection.

Animals↗

PubMedDate not supplied

[Recent aspects of acute and chronic inflammatory polyneuropathies: Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy].

INTRODUCTION: In last decade many advances have occurred in knowledge of pathogenic, in the different types of clinic expression and in the therapy of both acute and chronic polyneuritis. OBJECTIVE: To review the recent advances in the childhood expression of these disorders. DEVELOPMENT AND CONCLUSIONS: Into the broad term of Guillain-Barré syndrome (GBS) several types are considered: demyelinating, motor sensory axonal and motor axonal, and the Miller Fisher syndrome (MFS). Diagnostic criteria, clinical and neurophysiological are explained. The actual modes of treatment are reviewed, especially immunoglobulins and plasmapheresis. The chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare disease in childhood but it is necessary think on it when a picture of demyelinating polyneuropathy that seems the more frequent Charcot Marie Tooth type 1 polyneuropathy, because the treatment of CIDP changes radically the prognosis. Last advances of pathogenic, diagnostic criteria and treatment with corticosteroids, immunoglobulins and plasmapheresis are reviewed.

Guillain-Barre Syndrome↗

PubMed2002

Monofocal acute inflammatory Demyelination (MAID): a unique disorder simulating brain neoplasm.

BACKGROUND: Monofocal acute inflammatory demyelinating (MAID) lesions present as large masses that mimic brain tumors. The natural history and nosologic classification are not well defined. METHODS: Five patients with MAID from our files and 4 from the literature are presented. We defined MAID as a mass-like lesion, >4 cm in diameter. Demyelination was pathologically proven in all patients. RESULTS: Headaches and motor deficits were the most common presenting symptoms. Language problems and motor deficits were the most common findings on physical examination. After a median follow-up of 44 months, none of our 5 patients had multiple sclerosis. In similar cases, additional lesions indicative of multiple sclerosis developed within an average of 8 months. CONCLUSIONS: It may be difficult to distinguish MAID from brain tumor. It may be that MAID represents a unique form of isolated demyelinating disease, or it may represent transition to multiple sclerosis.

Adult↗

PubMed2002

Demyelination of vestibular nerve axons in unilateral Ménière's disease.

We conducted a study to determine whether vestibular nerves in patients with unilateral Ménière's disease whose symptoms are refractory to medical management exhibit neuropathologic changes. We also endeavored to determine whether retrocochlear abnormalities are primary or secondary factors in the disease process. To these ends, we obtained vestibular nerve segments from five patients during retrosigmoid (posterior fossa) neurectomy, immediately fixed them, and processed them for light and electron microscopy. We found that all five segments exhibited moderate to severe demyelination with axonal sparing. Moreover, we noted that reactive astrocytes produced an extensive proliferation of fibrous processes and that the microglia assumed a phagocytic role. We conclude that the possible etiologies of demyelination include viral and/or immune-mediated factors similar to those seen in other demyelinating diseases, such as multiple sclerosis and Guillain-Barré syndrome. Our findings suggest that some forms of Ménière's disease that are refractory to traditional medical management might be the result of retrocochlear pathology that affects the neuroglial portion of the vestibular nerve.

Adult↗

PubMed2002

[Central nervous system damage in inflammatory demyelinating polyneuropathies].

The results of subclinical brain damage study of 20 patients with inflammatory demyelinating polyneuropathy, aged 46.5 +/- 3.7 years, are presented. Eleven patients were diagnosed to have Guillain--Barre syndrome and 9--chronic inflammatory demyelinating polyneuropathy. No clinical systems for central nervous system damage were found. Magnetic resonance tomography defected demyelination foci in periventricular and sub-cortical brain regions in 35% of the patients and diffuse atrophic process--in 55%. Registration of brainstem acoustic-evoked potentials showed bilateral latency increase and a change of a signal shape in 60% of the patients. Possible mechanisms of combined damage of central and peripheral nervous system in this pathology are discussed.

Atrophy↗

PubMed1992

[Ca2+ channels and the abnormal electrical activity of demyelinated nerve].

Peripheral nerve demyelination was produced in adult rats by placing loosely-constrictive ligatures around the common sciatic nerve. The postoperative behavior of these rats indicated that hyperalgesia, allodynia and possible spontaneous pain were produced. In the meantime, abnormal spontaneous afferent activities (ectopic firings)originating from the demyelinated region were recorded. Evidence showed that the application of Ca2+ and Ca2+ channel blockers modulated the abnormal activity of the injured nerve. Ca2+ facilitation was dependent on its concentration (in the range of 10-20 mol/L), while 40mol/L Ca2+ always abolished firing. Verapamil, as well as La3+, applied locally or i. v. (for verapamil) not only strongly inhibited the spontaneous ectopic firings, but also blocked discharges elicited by tetraethylammonium. It is suggested that newly formed Ca2+ channels on the naked axolemma are largely responsible for the abnormal afferent activities following demyelination of the nerve.

Animals↗

PubMed1992

Pathogenesis of myelin breakdown in demyelinating diseases: role of proteolytic enzymes.

The mechanism by which the myelin sheath is degraded in demyelinating diseases is unknown. The demonstration of increased activities of both acid (cathepsins B, D, A) and neutral proteinases in tissue from experimental allergic encephalomyelitis (EAE) in animals and multiple sclerosis (MS, plaques) and the disappearance of myelin proteins implicate a role for proteolytic enzyme in myelin breakdown. The degradation of myelin basic protein (MBP) by proteinase yields encephalitogenic peptides and its loss has been found to cause structural alteration of the myelin sheath. This suggests that MBP degradation is an initial step in the breakdown of myelin in demyelinating diseases. A calcium-activated neutral proteinase (calpain), which degrades MBP, was found to increase in activity in MS tissue and cerebrospinal fluid (CSF), and its presence in myelin suggests that myelin may be autodigested in demyelinating disease. The source of increased proteinase activity has been indicated as macrophages, lymphocytes, and proliferative astrocytes (reactive cells). Increased proteinase activity is found in Schwann cells in Wallerian degeneration, and the presence of calpain in myelin-forming oligodendrocytes and Schwann cells suggests that these cells are likely sources of degradative enzymes. The involvement of proteolytic enzymes in the mechanism of myelin breakdown indicates the possible intervention with proteinase inhibitors for beneficial effect.

Animals↗

PubMed1992

[An autopsy case of chronic inflammatory demyelinating polyradiculoneuropathy with sever degeneration in the posterior column].

An autopsy case of chronic inflammatory demyelinating polyradiculoneuropathy was reported. It took a progressive course and terminated fatally in eight years. A 41-year-old man noticed motor disturbances when he tried to lift a bath pail and to write on July, 1978. Neurological examination revealed proximal dominant muscle atrophy, weakness of all extremities, and moderately diminished tendon reflex. Sensation was normal. The CSF showed albumin cytologic dissociations. Electromyogram showed neurogenic changes. Histological examination of biopsy specimen obtained from the anterior tibial muscle revealed severe neurogenic changes and showed axonal degeneration on the ventral tibial nerve. The treatment by corticosteroids was not effective, and the disease gradually progressed with repeated improvements and exacerbations. Three years after the onset, he showed vesicorectal dysfunctions. He died of respiratory failure on May, 1986. Neuropathological examination showed severe degeneration of middle root zones in the posterior columns, loss of myelinated fibers in Clarke's columns, demyelination and mild loss of axons accompanied by lymphocytic infiltration in the spinal roots, especially in the anterior roots. The histogram of cervical ventral root, ventral and dorsal roots of thoracic and lumbar regions revealed a decreased number of large myelinated fibers. A characteristic finding of this case was the dissociation of clinical features and neuropathological findings; the clinical features showed a typical motor neuropathy, but neuropathological examination showed severe degeneration on posterior columns of spinal cord like a sensory-ataxic neuropathy. Our observation suggest that the pathway which originates from posterior ganglion cells and runs into Clarke's columns passes through the middle root zones, since severe demyelination in Clarke's columns was observed.

Adult↗

PubMed2003

[Current opinions on the pathogenesis of demyelinating diseases. Part II].

Demyelinating diseases include a group of disorders in which destruction or degeneration of normal myelin occurs. In most cases these processes go on without primary lesion of axons. Demyelinization appears as a consequence of different pathogenetic factors like ischemia, injury, toxins and radiation. In this review a current view on the pathogenesis of demyelinating diseases is discussed, considering the achievements of molecular biology.

Demyelinating Diseases↗

PubMedDate not supplied

[Demyelinating lesions in cervical spinal cord and disability in multiple sclerosis patients].

BACKGROUND AND PURPOSE: In multiple sclerosis (MS) lesions appear both in brain and cervical cord. The aim of this study was to estimate the presence of MRI changes in cervical cord depending on the course, duration of the disease and a disability. MATERIAL AND METHODS: Clinical measures included 66 patients suffering from MS, the diagnosis was made according to McDonald's criteria. Patients were aged from 18 to 62 (41 women and 25 men). RESULTS: In patients with relapsing-remitting form (EDSS 1-4) single lesions were seen whereas secondary progressive patients (EDSS 3-7) had diffuse demyelinating lesions and primary progressive patients (EDSS 4-8)--both kinds of changes. It has been shown that the lesions occurred as the disease proceeds. Patients without demyelinating lesions in cervical cord had EDSS from 1 to 3 and the duration of their disease was longer than 10 years (benign MS). CONCLUSIONS: The duration of the disease depends on the presence and character of demyelinating lesions in cervical cord to a large extent. That dependence was not noticed in a primary progressive form. In benign MS there were no lesions in cervical cord.

Adolescent↗

PubMed2004

Multifocal acquired demyelinating sensory and motor neuropathy: report of a case and review of the literature.

Multifocal acquired demyelinating sensory and motor (MADSAM) neuropathy is characterized by an asymmetric multifocal pattern of motor and sensory loss, and conduction block and other features of demyelination in nerve conduction studies. MADSAM neuropathy needs to be differentiated from chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN). In classic CIDP, there are symmetric proximal and distal weakness, sensory deficit in both upper and lower extremities and reduced deep tendon reflex. In MMN, limb weakness without sensory loss is asymmetric in the distribution of individual peripheral nerves and the weakness typically begins in the distal upper extremities. We report one patient with chronic progression of asymmetric numbness and weakness in four extremities. MADSAM neuropathy was diagnosed after extensive clinical and laboratory evaluations. It is very important to distinguish between CIDP, MADSAM neuropathy, and MMN by clinical, laboratory, and histological features because of different effective therapeutic strategies.

Adult↗

PubMedDate not supplied

Demyelination and inhibition of tumor necrosis factor (TNF).

The development of tumor necrosis factor alpha (TNFalpha) inhibitor therapy is arguably the most significant achievement in the treatment of rheumatic diseases to date. One serious potential side effect associated with these agents is the onset of neurologic signs and symptoms. In this paper we will examine the relationship of TNFalpha antagonism and demyelinating disease. Reviewing early laboratory and animal models, we discuss the mechanism of TNFalpha in central nervous system (CNS) injury and repair. Two negative studies of TNFa inhibitor therapy in the treatment of refractory multiple sclerosis (MS) are considered. From the manufacturers' clinical development programs and post-marketing adverse event reporting data, we report the current incidence of demyelinating symptoms associated with each of the commercially available anti-TNFa agents. Comparing these reports to the incidence of MS in society as a whole, we find the rate of new cases of neurologic disease in exposed patients is not different from the rate of expected cases. Finally we explore arguments that support and refute a potential biologic relationship between TNFa neutralization and demyelinating disease.

Antibodies, Monoclonal↗

PubMed2005

[Magnetic-resonance tomography in differential diagnosis of brain lesions in demyelinating and systemic autoimmune diseases].

An aim of the study was to establish MRT signs that may be useful for differential diagnosis of multiple sclerosis (MS). Three groups of patients have been examined: 300 patients with MS, 35 with demyelinating diseases (acute disseminated encephalomyelitis, neuromyelitis optica--Devic's syndrome); 90 patients with systemic autoimmune diseases (systemic lupus erythematosus, primary antiphospholipid syndrome, sclerodermatitis, Sjugren's syndrome, autoimmune thyroiditis, vasculitis and vasculopathy). Classification of MRT syndromes in MS and their frequency are presented: syndrome of chronic inflammatory demyelination (79%), syndrome of acute inflammatory demyelination (9%), syndrome of multifocal degenerative leucoencephalopathy (8%), syndrome of combined multifocal diffusive leucoencephalopathy (4%). The similarity and differences in MRT semiotics of the above diseases and MS are described.

Adolescent↗

PubMed2005

[A case of asymmetric demyelinating neuropathy in a patient with chronic graft-versus-host disease].

A 47-year-old man, who suffered from acute lymphocytic leukemia at 45 years old and was treated with hematopoietic stem cell transplantation at 46 years old after the induction of complete remission by the standard chemotherapy, developed the symptoms of chronic graft-versus-host disease (cGVHD) such as dry eyes, dry mouth, skin thickening, skin scaling, skin pigmentation and impaired liver function. He was admitted to our hospital because of the acute development of diplopia and weakness of his left upper extremity accompanying with the exacerbation of other symptoms of cGVHD. Neurological examinations revealed the right abducens nerve palsy and asymmetric muscular weakness of the extremities; the proximal part of the left upper extremity and the distal part of the right upper extremity were markedly involved. Neurophysiological studies including magnetic motor root stimulation revealed demyelinating neuropathy specifically involving the motor nerves. On the basis of these findings, a diagnosis of peripheral neuropathy associated with cGVHD was made. Nighteen reports are available on peripheral neuropathy in cGVHD patients, but to date little is known about the pathophysiology of this condition. Most of those patients have been diagnosed as having symmetric demyelinating polyneuropathy, such as Guillain-Barré syndrome or chronic inflammatory demyelinating polyneuropathy. In this study, contrary to previous reports, the asymmetric involvement of motor nerves is noteworthy. Accumulation and further analyses of the cases like the present case are necessary to elucidate the pathogenesis of peripheral neuropathy in cGVHD.

Chronic Disease↗

PubMed2006

[Chronic inflammatory demyelinating polyneuropathy followed by systemic lupus erythematosus and Sjögren syndrome: a case report].

We report a 60-year-old man with chronic inflammatory demyelinating polyneuropathy (CIDP) accompanying systemic lupus erythematosus (SLE) and Sjögren syndrome (SS). He was admitted to our hospital because of progressive weakness and dysesthesia in the distal parts of the bilateral upper and lower extremities. We diagnosed the illness as CIDP and treated him with steroids, plasma filtration and high-dose intravenous immunoglobulin therapy (IvIg). Consequently, his symptoms improved gradually and he was discharged. However, 2 years after the first admission, he experienced dyspnea on effort and chest X-ray demonstrated right pleural effusion. Consequently, he gradually developed gait disturbance, loss of taste, and severe dysesthesia in his lower limbs. Therefore, he was admitted again. On neurological examination, mild weakness was detected in all limbs distally. Deep tendon reflexes were absent. The sensation of position and vibration was diminished in the fingers and toes. He could not walk by himself and demonstrated an ataxic gait with a wide base. Examination of cranial nerves demonstrated no abnormalities, except for loss of taste. Serological examination demonstrated positive auto-antibodies including antinuclear, anti-DNA, and anti-SS-A antibodies. Urinalyses showed albuminuria and microscopic hematuria. Cerebrospinal fluid (CSF) was clear and colorless, containing 3 mononuclear cells per cubic mm, with a protein of 275 mg/dl. Magnetic resonance images (MRIs) of the brain and entire spine were normal. Neurophysiological studies demonstrated an absence of sensory nerve action potentials in the right arm and markedly slow conduction velocities, conduction block in the ulnar forearm segment and absence of F waves in all limbs. The renal biopsy revealed lupus nephritis. The lip biopsy demonstrated chronic sialoadenitis consistent with SS, altough patient did not show symptoms of arthritis or vasculitis. It is well known that mononeuritis multiplex and acute demyelinating polyneuropathy accompany SLE. However there are few reports that describe the occurrence of CIDP in patients with SLE, and the association of "CIDP-like" neuropathy in patients with SS. Our case suggests that the autoimmune disease associated with SLE and SS may induce "CIDP-like" inflammatory demyelinating polyneuropathy.

Antibodies, Antinuclear↗

PubMed1991

Exacerbation of inflammatory demyelinating polyneuropathy after bone marrow transplantation.

Two patients with hematologic malignancy and quiescent inflammatory demyelinating polyneuropathy developed severe exacerbations of polyneuropathy at the time of bone marrow transplantation. The clinical course in both patients was progressive despite therapy with immuno-suppressive agents, plasmapheresis, and high dose immunoglobulin. The polyneuropathy resulted in quadriplegia which contributed to the patients' deaths 175 and 48 days after transplantation. Sections of multiple peripheral nerves sampled post mortem in the first case revealed prominent demyelination with heavy infiltration of macrophages and lymphocytes. Immunohistochemical studies demonstrated that most of the lymphocytes were of the CD8+, cytotoxic/suppressor cell class and that many of the Schwann cells expressed class II (HLA-DR) antigen. This report suggests that bone marrow transplantation can exacerbate inflammatory demyelinating polyneuropathy.

Adult↗