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Query: UMLS:C0085584 (encephalopathy)
 18,178 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The clinical and neuroradiological findings of two patients with X-linked agammaglobulinemia, who developed a chronic encephalopathy, are presented. The main neurological manifestations in both patients were: progressive spastic tetraparesis, cortico-subcortical type of dementia and seizures. No infectious agent was identified in either patient. A systematic review of the clinical findings of 37 patients reported in the literature with X-linked agammaglobulinemia and chronic encephalopathy allows the distinction of two subgroups of patients according to their form of presentation (acute or insidious). In each subgroup there are significant clinical differences. The clinical-neuroradiological similarities between this complication and the ones derived from the vertically transmitted form of the human immunodeficiency virus are pointed out. Finally, emphasis is made on the need for CSF viral cultures on patients with X-linked agammaglobulinemia as soon as a neurological complication is suspected.
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PMID:[Chronic encephalopathy in patients with sex-linked agammaglobulinemia]. 825 46

In 10 children infected by HIV at birth, who presented early and severe immunodeficiency encephalopathy, the lesions observed in the central nervous system were different from those found in adults. Using standard neuropathological techniques, the main abnormalities were white matter palor and atrophy, pyramidal tract demyelination, moderate perivascular inflammation, numerous calcifications of blood vessels in basal ganglia, white matter and occasional in the cortex, few opportunistic infections including cytomegalovirus ventriculitis, polymorphonuclear microabcessses and aspergillus abscesses; no toxoplasma was detected. An 18-month-old girl presented with an angiocentric lymphoproliferative disorder in central and peripheral nervous system and muscle, with predominance of B cells. In most cases, low levels of HIV replication were detected in brain tissue, as demonstrated by the presence of only few microglial nodules and giant cells, feeble detection of HIV p24 and p17 antigens by immunocytochemistry, in situ hybridization of HIV DNA and RNA and polymerase chain reaction, despite severe clinical encephalopathy. Zidovudine did not improve any patient. In children with severe AIDS encephalopathy, HIV might not be directly implicated in the central nervous system lesions: an intermediate factor such as cytokines or another toxic substance secreted by activated macrophages and/or lymphocytes, could induce severe lesions in the central nervous system and minor pathology of the peripheral nervous system and muscles.
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PMID:[A neuropathological study of 10 HIV-infected children]. 833 60

Qualitative analysis of 100 consecutive computed tomographic (CT) studies of the brain in children with symptomatic but untreated acquired immunodeficiency syndrome was performed. After excluding children with associated medical illnesses that might confound the diagnosis of encephalopathy or alter brain structure, an abnormality of at least one of the measures of ventricular size, cortical atrophy, white matter attenuation (leukoaraiosis), or cerebral calcification was found in 86% of the patients studied. Ventricular enlargement was the most common abnormality, followed by cortical atrophy, leukoaraiosis, and cerebral calcification. Cerebellar atrophy was an unexpected but relatively common finding in 12% of the children. Sixty-five percent of the children were encephalopathic at the time of evaluation. All 16 children with cerebral calcification were encephalopathic and had acquired human immunodeficiency virus (HIV) through vertical transmission. Encephalopathic children were significantly younger and had significantly greater abnormality ratings on each CT measure when compared with the nonencephalopathic children. Discriminant analysis using age and the qualitative CT measures was applied as a method to identify the presence of encephalopathy. CT measures proved to have a specificity and a sensitivity of only 76%. We conclude that abnormalities of cerebral structure are seen in a high percentage of children symptomatic with HIV. Although most of the children are encephalopathic, CT abnormalities are seen in children without encephalopathy, suggesting presymptomatic brain disease. The presence of cerebral calcification on CT suggests in utero infection with HIV and the presence of encephalopathy.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The prevalence of computed tomographic abnormalities of the cerebrum in 100 consecutive children symptomatic with the human immune deficiency virus. 833 44

Human foamy virus (HFV) is a retrovirus encoding structural genes and, like human immunodeficiency virus and human T cell leukemia virus I, several ancillary reading frames collectively termed the be1 genes. We have previously shown that HFV transgenic mice develop an encephalopathy with neuronal loss in hippocampus and cerebral cortex. We have now raised and characterized rabbit antisera to various recombinant portions of gag, pol, env, and bel-1, the viral trans-activator. Immunoreactivity for gag and bel-1 was observed in nuclei and processes of hippocampal and cortical neurons before the onset of morphological lesions and correlated with the appearance of HFV mRNA. Astrocyte-derived multinucleated giant cells containing HFV proteins were present in the brain of transgenic mice coexpressing full-length HFV genes but not in mice expressing truncated gag and env, suggesting that these genes contain a fusogenic domain. Expression of full-length structural genes decreased the life expectancy of transgenic mice, implying an adjuvant role for these proteins in HFV-induced brain damage.
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PMID:Human foamy virus proteins accumulate in neurons and induce multinucleated giant cells in the brain of transgenic mice. 838 40

We have studied longitudinally ten patients with AIDS encephalopathy with respect to pathogenetic roles of human immunodeficiency virus (HIV) and cytomegalovirus (CMV). Three patients manifested typical AIDS dementia complex (ADC) (initially without retinitis and with slowly progressive cognitive, motor and behavioral abnormalities which were zidovudine-responsive, and relatively preserved CD4+ T cells), and seven patients presented with AIDS dementia complex complicated by CMV encephalopathy (ACE) (with CMV retinitis, peripheral neuropathy, altered sensorium, and rapidly declining clinical and immunological status). Whereas only HIV antibody was elevated in the spinal fluid of patients with ADC, both virus infections were active in the central nervous system of patients with ACE as shown by HIV p24 antigenemia and antigenrrhachia, elevated HIV and CMV antibody in the spinal fluid, disseminated CMV infection with retinitis, and basilar ventriculoencephalitis with multinucleated cytomegalic cells containing CMV and HIV proteins and CMV DNA. The recognition of ADC and ACE is important, since some patients with ACE may respond to ganciclovir or foscarnet.
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PMID:AIDS dementia complex complicated by cytomegalovirus encephalopathy. 838 34

Experimental intravenous challenge of 8-week-old kittens with the feline immunodeficiency virus Maryland isolate (FIV-MD) was investigated for its ability to infect the central nervous system (CNS) and induce neurologic abnormalities. Six cats were inoculated with 1,000 TCID50 units of FIV-MD isolate, with six age-matched cats serving as uninfected controls. Clinical and immunological evaluation documented that challenged cats developed immunodeficiency and growth delay. Neurologic examination revealed an abnormal stereotypic motor behavior consisting of repetitive, compulsive roaming that developed as early as 4 weeks postinfection (PI) and persisted throughout the 16-month study in three cats. Serial neuroelectrodiagnostic evaluation revealed persistent abnormal electroencephalographic recordings in three infected cats. Serial evoked potential (EP) recordings at 3, 8, and 12 months PI demonstrated significantly prolonged interpeak latencies III-V at 3 months PI and I-III at 12 months PI for brainstem EP recordings. Alterations of visual EPs were detected only at the 3-month time period. Retinocortical time, however, was significantly different from that in control cats at 3 and 12 months PI. Magnetic resonance imaging evaluation of FIV-MD-infected cats at 12 months PI revealed cortical atrophy, mild ventricular enlargement, and discrete white matter lesions. At 16 months PI, however, histopathological examination of brain tissue indicated only mild lesions limited to satellitosis and perivascular lymphocytic infiltrates. Virus was detected in the CNS by reverse transcriptase, immunofluorescence, and antigen capture. Evaluation of the cerebrospinal fluid revealed intrathecal anti-FIV-MD antibody despite lack of detectable viremia in five challenged cats. Collectively, these findings demonstrate the induction of virus-associated neurologic disease following parenteral FIV challenge in conjunction with an immunodeficiency state. The nature of the nervous system infection is analogous to HIV-1 pediatric encephalopathy.
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PMID:AIDS-associated encephalopathy with experimental feline immunodeficiency virus infection. 838 49

Expression of adhesion proteins on human microglial cells was studied by immunocytochemistry. Both microglial cells and peripheral blood monocytes expressed beta 2 integrins and molecules of the immunoglobulin superfamily at similar levels whereas the expression of the beta 1 integrins (alpha 2-VLA (very late antigen), alpha 4-VLA, alpha 5-VLA, alpha 6-VLA) was higher on microglial cells than on monocytes. Stimulation of microglial cells with interleukin-1 alpha and tumour necrosis factor-alpha, the main cytokines detected in HIV1-infected central nervous system (CNS), increased the microglial expression of alpha 1-VLA, intercellular adhesion molecule-1, vascular cell adhesion molecule-1 and beta 2-LFA-1 (leukocyte-function-associated molecule-1) but not of alpha L-LFA-1. Such an induction of adhesion molecules could facilitate penetration of HIV1-infected monocytes into brain parenchyma and their adhesion to CNS cells, and could maintain a chronic inflammation during human immunodeficiency virus-1 (HIV1) encephalopathy.
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PMID:Adhesion proteins on human microglial cells and modulation of their expression by IL1 alpha and TNF alpha. 844 77

HIV encephalopathy, which is probably primarily caused by human immunodeficiency virus, is the most common neurological disorder in HIV-infected patients and is more frequent than opportunistic diseases of the central nervous system. It is characterized most often by slowly progressing cognitive impairment, psychomotoric slowing and increasing apathy. The syndrome is found almost exclusively in the late stages of HIV infection; its frequency in patients with full-blown AIDS is estimated as being between 40 and 70%. Although numerous studies have demonstrated alterations in the electrophysiological parameters, cerebral perfusion and cerebrospinal fluid in many asymptomatic patients, there are no reliable parameters that can predict the risk of developing HIV encephalopathy. Also, there is no sufficient correlation between the extent of the frequent but mostly subtle neuropathological changes and the clinical degree of the severity of the encephalopathy. The mechanisms causing cerebral injury are poorly understood. Recent studies indicate that the indirect effects of HIV infection of the brain are the most important pathogenetic factors. In particular, certain viral proteins and cytokines produced by infected macrophages or activated microglia seem to induce neuronal dysfunction and finally loss of nerve cells.
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PMID:[HIV encephalopathy--clinical aspects, neuropathology and pathogenesis]. 845 Aug 99

Early HIV infection of the CNS, as demonstrated by cerebrospinal fluid studies, seems relatively common. However most HIV carriers remain neurologically unimpaired during the incubation period. A few psychometric, radiological, and electrophysiological studies suggest that neurological abnormalities are present at early stages of HIV infection; the findings of these studies are controversial and until recently, they have not been supported by neuropathological data. Early brain changes, including leptomeningitis and vasculitis with myelin pallor and gliosis of the deep white matter are probably secondary to vascular inflammation and opening of the blood-brain barrier. Such conclusions are drawn from the examination of brains of asymptomatic HIV-positive individuals who died from unnatural causes, and of rare cases with acute fatal encephalopathy revealing HIV infection. In addition, early experimental simian immunodeficiency virus infection and feline immunodeficiency virus encephalopathy have demonstrated similar changes to those in man. Although small amounts of viral genome were detected by PCR in a few cases, the early changes in the human brain do not seem to result from a productive HIV infection of the CNS, as seen in HIV encephalitis. The occurrence of a usually asymptomatic and transient immunopathological reaction coinciding with early HIV infection of the nervous system appears to be more likely.
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PMID:Early central nervous system changes in human immunodeficiency virus (HIV)-infection. 847 97

Zidovudine is a dideoxynucleoside analogue of thymidine. It acts by interfering with viral reverse transcriptase, thereby inhibiting human immunodeficiency virus (HIV) replication. Zidovudine has been shown in clinical trials to prolong survival of patients with acquired immune deficiency syndrome (AIDS) and advanced AIDS-related complex (ARC), and to delay progression to ARC or AIDS in patients with earlier disease. At the present time it is suggested that zidovudine be initiated when the CD4 lymphocyte count is less than 500 cells/mm3. Recent studies have suggested a delay in the development of AIDS in patients with CD4 counts over 500 cells/mm3, but ongoing studies will require confirmation. The adverse reactions associated with zidovudine have been well described. It appears that haematological toxicity is associated with both the dose and stage of disease. Anaemia may present more often within the first 3 months of therapy, whereas neutropenia can occur early or late. Mild headache and gastrointestinal intolerance may occur early and in some cases limit tolerance to the drug. A number of neurological adverse reactions have been reported rarely including seizures and dose-reduction encephalopathy. The most significant late adverse reaction is that of myopathy, which occurs in patients receiving zidovudine for more than 6 months. With careful monitoring, the adverse reactions of zidovudine are manageable and patient tolerance of the medication is acceptable.
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PMID:Zidovudine toxicity. Clinical features and management. 848 Dec 17


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