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Query: UMLS:C0014070 (encephalomyelitis)
 13,017 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cytomegalovirus (CMV) infection of the nervous system is frequent in acquired immunodeficiency syndrome (AIDS) and can be responsible for encephalitis, encephalomyelitis, meningoradiculitis or polyradiculo-neuropathy. Encephalitis is characterized at microscopy by its periventricular and cerebellar location, and by the presence of cytomegalic cells, containing intranuclear and/or intracytoplasmic inclusions, microglial nodules and necrotic foci. The virus can infect almost all types of cells. Coexistence of CMV and HIV has been observed in giant cells of macrophagic origin. It has been suggested that the two viruses could act in synergy. The nervous system is seldom infected by the varicella-zoster virus (VZV) in AIDS. The infection can be responsible for multifocal leukoencephalitis, ventriculitis, vascular lesions associated or not with cerebral infarction, or with meningomyeloradiculitis. In almost all cell types Cowdry's type A intranuclear inclusions have been found. The virus can be demonstrated by immunohistochemistry or in situ hybridization. VZV antigens have been reported in the walls of vessels damaged by a non inflammatory obliterating vasculopathy or by a granulomatous angiitis. Coexistence of VZV and HIV has been observed in giant cells of macrophagic origin, and synergy between those two viruses has been suspected.
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PMID:[Pathologic anatomy of cytomegalovirus encephalomyelitis and varicella-zona virus encephalomyelitis]. 747 34

Autoreactive T cells specific for myelin basic protein (MBP), a major component of central nervous system (CNS) protein, are frequently found in blood and cerebrospinal fluid of patients with postinfectious encephalomyelitis. This autoimmune syndrome is a CNS complication after infections with a number of different enveloped viruses, e.g. mumps, measles, rubella, influenza and varicella. However, the pathophysiological mechanism leading to this breaking of natural self tolerance in the course of viral infection remains an enigma. A long-lasting hypothesis has suggested that incorporation of cellular (self) proteins into the envelope of budding viruses might be a possible mechanism leading to autosensitization. In a model study we demonstrate here that vesicular stomatitis virus (VSV), grown in myelin protein-expressing cell cultures, is highly efficient in triggering T cell responses to MBP in vitro and can prime autoreactive T cell immune responses in vivo. On the basis of these findings, we suggest that incorporation of CNS membrane components into the viral envelope and subsequent priming of self-reactive immune responses might be the common pathogenic mechanism underlying the postinfectious encephalomyelitis syndrome.
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PMID:Autoimmunity caused by host cell protein-containing viruses. 753 Dec 73

Varicella (chickenpox) is the primary infection of Varicella-Zoster virus, characterized by generalized vesicular eruption, fever and mild constitutional symptoms. Chiefly infecting children of 1 to 14 years of age, the disease has been almost neglected because of its inevitable and benign outcome. Adults are rarely infected with an incidence of less than 20%. These two cases are presented of normal adults with marked neurological complications 10 and 14 days, respectively, following typical skin eruption of varicella. The first case developed transverse myelitis and the second, an encephalomyelitis. Neurological complications are very rare post-varicella infection. Although prognosis is good and complete recovery is the rule, still some morbidity with neurological sequelae and mortality have been reported. The present cases had extensive neurological deficit, despite aggressive treatment, making a high index of suspicion for differential diagnosis in patients who present with encephalitis. Especially following the typical exanthema of varicella, this possibility is emphasized and the literature is reviewed.
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PMID:Neurological complications of varicella: a report of two cases. 800 33

We describe a case of acute disseminated encephalomyelitis following varicella infection presenting as transverse myelitis. Magnetic resonance imaging revealed diffuse cord swelling and signal increase without gadolinium enhancement and several silent brain lesions, all of which completely resolved at follow-up.
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PMID:Brain and spinal cord MR imaging in a case of acute disseminated encephalomyelitis. 908 69

Acute disseminated encephalomyelitis (ADEM) occurs late in the course of viral infection, mainly exanthematous diseases such as measles, chicken pox, and rubella. Postinfectious encephalomyelitis is characterized by immune-mediated demyelination, which is found in experimental autoimmune encephalomyelitis (EAE), and virus cannot be isolated from the central nervous system. The investigations using animal models infected with. Theiler's virus or measles virus would be very useful for clarifying the mechanisms of demyelination induced by viral infection. Although the incidence of postvaccinal encephalomyelitis has fallen markedly due to development of vaccines, the neurological complications following immunization are still reported. The vaccines prepared from viruses other than live-attenuated viruses and whole-killed organisms have never been proved to induce ADEM.
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PMID:[Acute disseminated encephalomyelitis]. 910 97

Infections of the central nervous system by Herpes simplex viruses (Herpes simplex type 1 and Herpes simplex type 2) are uncommon in acquired immune deficiency syndrome and are often clinically and pathologically atypical. We have collected 11 cases of herpes simplex encephalomyelitis in AIDS patients reported in the literature. Only 3 of these cases presented with a typical, necrotizing, limbic encephalitis. Other clinicopathological patterns included ventriculitis, rhombencephalitis and myelitis. Ventriculitis and rhombencephalitis were usually due to infection by HSV-1, whereas myelitis was mostly due to HSV-2 infection. Distinction between the 2 types of virus is often difficult by immunohistochemistry due to frequent cross reactivity and usually requires tissue culture, in situ hybridization, or polymerase chain reaction. Association of HSV encephalomyelitis with productive infection of the central nervous system by the human immunodeficiency virus was only found in one case. In contrast, co-infection with cytomegalovirus was found in 9 of the 11 cases. One case also had had varicella zoster virus vasculitis, and another case also had a cerebral malignant non Hodgkin's lymphoma in which Epstein Barr virus genome was identified. This supports the view that concomitant herpes-virus infections of the central nervous system is a characteristic feature of AIDS.
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PMID:[Central nervous system infection due to Herpes simplex virus in AIDS]. 938 7

Demonstration of the direct involvement of cranial blood vessels by varicella zoster virus (VZV) is facilitated by immunohistochemistry (IHC), in situ hybridization (ISH) and polymerase chain reaction (PCR) techniques. The extent to which an inflammatory vasculitis serves as the pathogenic mechanism for VZV encephalomyelitis (VZVE) is still, however, debated. Most VZVE patients are immunocompromised and show little inflammation, either pre-mortem in cerebrospinal fluid (CSF) or at autopsy. We describe an HIV-positive patient with a moderately depressed CD4 count (304) who presented with massively elevated CSF protein (1800 mg/dl), bloody CSF and pleocytosis (1300 white blood cells (WBC)/mm3). His CSF was positive for VZV DNA by PCR. He was treated with acyclovir and foscarnet, but died. At autopsy, an unusually widespread, inflammatory, transmural vasculitis caused by VZV affected meningeal vessels at virtually all brain stem and spinal cord levels, causing multiple subpial hemorrhages and necrosis. Virus DNA in multiple areas of brain, brainstem and spinal cord was readily revealed by PCR, but not by the presence of viral inclusions, IHC or ISH. This case, with a clinically confusing presentation for VZVE, illustrates the extensive, albeit infrequent, degree of necrotizing vasculitis and CSF abnormalities that VZV is capable of producing. Antiviral therapy may have inhibited VZV genome replication and subsequent antigen production, resulting in negative ISH and IHC studies, but generated increased VZV genomic fragments that were detectable by the more sensitive PCR technique.
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PMID:Profound cerebrospinal fluid pleocytosis and Froin's Syndrome secondary to widespread necrotizing vasculitis in an HIV-positive patient with varicella zoster virus encephalomyelitis. 974 10

Clinical and MRI appearances were reviewed in 25 cases of acute disseminated encephalomyelitis (ADEM) seen in a university hospital in South India. Specific viral infections and Semple antirabies vaccination together accounted for 56% of antecedent events. Clinical and MRI features were suggestive of diffuse/multifocal form in 15 patients. Of the 10 patients with clinically site restricted forms, two patients with dorsal myelitis and one patient with polyradiculitis had asymptomatic cerebral white matter lesions. MRI was essentially normal in all the four patients with acute ataxia following varicella infection. Of the 13 patients with multiple white matter lesions, lesions were asymmetrical in size and morphology in nine patients and symmetrical in four patients. Two of them had extensive destructive lesions and one patient had multiple discrete lesions. Lesions occurred at the corticomedullary junctions in seven patients. The distribution was subcortical and/or centrum semiovale in 10 patients. The regions affected include internal capsule(s), thalami, brainstem, cerebellar peduncles and cerebellum. No specific differences were observed in patients with ADEM following specific viral infections, Semple antirabies vaccination, and nonspecific upper respiratory tract infections. There was fairly good correlation between clinical and MRI findings in 81% of patients. Patients with incomplete recovery showed extensive and/or multifocal lesions.
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PMID:Acute disseminated encephalomyelitis: clinical and MRI study from South India. 1045 Jul 98

Acute transverse myelitis (ATM) with moderate symptomatology and smaller multiple magnetic resonance imaging lesions is often caused by multiple sclerosis. Severe ATM with extensive magnetic resonance imaging lesions with or without associated meningitis often has a viral cause, particularly in the younger age groups, whereas vascular disorders may prevail among older patients. Previously, one had to rely on indirect evidence such as viral serology or viral identification in throat washings to confirm a diagnosis of myelitis. Thus, mycoplasma myelitis may occur coincident with a mycoplasma pneumonia. Viral myelitis is now often diagnosed by specific polymerase chain reaction of the cerebrospinal fluid, for echovirus, Coxsackie virus, mumps virus, herpes simplex virus or varicella-zoster virus, but an autoimmune component may still be important. An anterior horn syndrome may be produced by the tick-borne encephalomyelitis virus. Severe ATM may also be a postinfectious or postvaccinal disorder [i.e. a partial acute disseminated encephalomyelitis (ADEM)]. Neuromyelitis optica, a combination of severe myelitis and optic neuritis, is often a manifestation of ADEM or systemic lupus erythematosus. Many of these disorders are potentially treatable with specific antiviral agents or immunosuppression. 'Idiopathic' ATM is probably a consequence of inadequate examination and follow up. The differential diagnoses-viral myelitis, multiple sclerosis, ADEM, neuromyelitis optica, spinal arteriovenous malformation and arteritis-should be considered and are usually identified by a rapid diagnostic work-up, leaving few ATM cases undiagnosed.
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PMID:Myelitis. 1087 Dec 57

Fifty cases of postinfectious encephalomyelitis admitted to our Pediatric Department during the period 1980 to 1997 were consecutively collected and reviewed. There were 28 males and 22 females. The age of onset ranged from 9 months to 14 years. The antecedent infections included measles (6 cases), rubella (5 cases), mumps (4 cases), chicken pox (4 cases), Epstein-Barr virus infection (11 cases), mycoplasma infection (6 cases), and unknown etiology (14 cases). The cessation of measles, rubella, and mumps as causes for encephalomyelitis in our patients corresponds with the introduction of a measles-mumps-rubella nationwide vaccination program in Taiwan commencing in 1992. The main clinical symptoms were fever, headache, and/or vomiting, seizure, and motor weakness. The presenting signs included altered consciousness, meningeal signs, cranial nerve palsy, brainstem signs, involuntary movement, and cerebellar signs. Computed tomography scans were abnormal for 14 (56%) of 25 patients studied, whereas magnetic resonance imaging (MRI) disclosed lesions in 14 (82%) of 17 patients, with abnormal signals in various parts of the cerebral hemisphere, as well as in the basal ganglion, diencephalon, midbrain, brain stem, and cerebellum. Of the three patients with negative MRI findings, an abnormal finding on somatosensory evoked potential was noted for one patient, and a focal decrease in tracer uptake on single photon emission computed tomography (SPECT) was found for the other two patients. This study demonstrates that the causative agents of postinfectious encephalomyelitis in Taiwan have changed from those of traditional exanthematous diseases to nonspecific respiratory infections and suggests that this may also be the case in other parts of the world. MRI remains the imaging method of choice, whereas other neurofunctional studies such as evoked potentials and SPECT are complementary for the diagnosis.
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PMID:Postinfectious encephalomyelitis: etiologic and diagnostic trends. 1106 80


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