Acute myelopathies: Clinical, laboratory and outcome profiles in 79 cases.
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The main aetiologies of acute myelopathy (AM) are: multiple sclerosis, systemic disease (SD), spinal cord infarct (SCI), parainfectious myelopathy (PIM) and delayed radiation myelopathy (DRM). Although a large amount of data have been published for each individual aetiology, comparison studies are scarce. The aim of this study was to assess the various aetiological and outcome profiles of AM. We studied 79 cases: 34 (43%) in multiple sclerosis; 13 (16.5%) in SD; 11 (14%) in SCI; five (6%) in PIM; and three (4%) in DRM. Myelopathies were of unknown origin in 13 (16.5%) patients. We evaluated clinical, spinal cord and brain MRI, CSF and evoked potentials data at admission, MRI outcome at 6 months and clinical outcome at 12 months. A statistical comparison of clinical, laboratory and outcome data was only performed between multiple sclerosis, SD and SCI patients due to the small number of cases in the other groups. A motor deficit was more frequent in SD and SCI than in multiple sclerosis where initial symptoms were predominantly sensory (P < 0.001). Spinal cord MRI showed lateral or posterior lesions of less than two vertebral levels in multiple sclerosis, in contrast to SD and SCI, where lesions involved more vertebral levels and were centromedullar (P < 0.001). Brain MRI was most frequently abnormal in multiple sclerosis (68%), but was also abnormal in 31% of SD patients (P < 0.05). Oligoclonal bands in CSF were more frequent in multiple sclerosis than in SD (P < 0.001) and were never found in SCI. Clinical outcome at 12 months was good in 88% of multiple sclerosis cases, and poor or fair in 91% of SCI and 77% of SD. Aetiologies of AM may be differentiated on the basis of clinical, spinal cord and brain MRI, CSF and outcome data, and allow a probable diagnosis to be made in previously undetermined cases. These findings may have therapeutic implications for cases with a questionable diagnosis. (+info)
Kir4.1 potassium channel subunit is crucial for oligodendrocyte development and in vivo myelination.
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To understand the cellular and in vivo functions of specific K(+) channels in glia, we have studied mice with a null mutation in the weakly inwardly rectifying K(+) channel subunit Kir4.1. Kir4.1-/- mice display marked motor impairment, and the cellular basis is hypomyelination in the spinal cord, accompanied by severe spongiform vacuolation, axonal swellings, and degeneration. Immunostaining in the spinal cord of wild-type mice up to postnatal day 18 reveals that Kir4.1 is expressed in myelin-synthesizing oligodendrocytes, but probably not in neurons or glial fibrillary acidic protein-positive (GFAP-positive) astrocytes. Cultured oligodendrocytes from developing spinal cord of Kir4.1-/- mice lack most of the wild-type K(+) conductance, have depolarized membrane potentials, and display immature morphology. By contrast, cultured neurons from spinal cord of Kir4.1-/- mice have normal physiological characteristics. We conclude that Kir4.1 forms the major K(+) conductance of oligodendrocytes and is therefore crucial for myelination. The Kir4.1 knock-out mouse is one of the few CNS dysmyelinating or demyelinating phenotypes that does not involve a gene directly involved in the structure, synthesis, degradation, or immune response to myelin. Therefore, this mouse shows how an ion channel mutation could contribute to the polygenic demyelinating diseases. (+info)
Pallido-pyramidal syndrome treated with levodopa.
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Two siblings are reported who developed classical signs and symptoms of Parkinsonism in the first decade of life. In addition, they had evidence of cortical spinal tract disease, thus putting them in the category of Davison's pallido-pyramidal syndrome. Both deteriorated to the point of a non-productive existence until the institution of levodopa treatment, at the ages of 18 and 20 years. The response of the extrapyramidal signs plus the lack of response of the pyramidal tract signs demonstrate the specificity of a pharmacological agent in certain areas of the nervous system. The rapid response of the female patient to very low doses of levodopa is unusual in our experience. Both patients have remained well for eight months after initiation of treatment. (+info)
Recognizing spinal cord emergencies.
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Physicians who work in primary care settings and emergency departments frequently evaluate patients with neck and back pain. Spinal cord emergencies are uncommon, but injury must be recognized early so that the diagnosis can be quickly confirmed and treatment can be instituted to possibly prevent permanent loss of function. The differential diagnosis includes spinal cord compression secondary to vertebral fracture or space-occupying lesion, spinal infection or abscess, vascular or hematologic damage, severe disc herniation and spinal stenosis. The most important information in the assessment of a possible spinal cord emergency comes from the history and the clinical evaluation. Physicians must look for "red flags"--key historical and clinical clues that increase the likelihood of a serious underlying disorder. In considering diagnostic tests, physicians should apply the principles outlined in an algorithm for the evaluation of low back pain prepared by the Agency for Healthcare Research and Quality (formerly the Agency for Health Care Policy and Research). Computed tomography and magnetic resonance imaging can clearly define anatomy, but these studies are costly and have a high false-positive rate. Referral of high-risk patients to a neurologist or spine specialist may be indicated. (+info)
Atheromatous emboli to the lumbosacral spinal cord.
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The lumbosacral spinal cords of 28 patients with atheromatous emboli to abdominal viscera and/or grafts to the abdominal aorta were examined by serial sections. In 12 patients, atheromatous emboli were found in spinal arteries, most commonly in the sacral cord, and most frequently in the anterior spinal artery. The general absence of spinal cord infarctions was attributed to the nature of the emboli, apparent good collateral circulation, and the absence of diffuse atherosclerosis. However, 38% of the patients had arteriosclerosis; this was generally focal and not associated with significant luminal narrowing. Only one patient had infarction, which was limited primarily to the gray matter. It would appear that hypoperfusion must exist in conjunction with atheromatous emboli in order for infarction to develop. Organized atheromatous emboli also caused focal ischemic atrophy of neurons. It is postulated that this change may be the morphological basis for some of the atypical lower motor neuron diseases found in the elderly. (+info)
In vivo expression of major histocompatibility complex molecules on oligodendrocytes and neurons during viral infection.
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Demyelination in multiple sclerosis and in animal models is associated with infiltrating CD8+ and CD4+ T cells. Although oligodendrocytes and axons are damaged in these diseases, the roles T cells play in the demyelination process are not completely understood. Antigen-specific CD8+ T cell lysis of target cells is dependent on interactions between the T cell receptor and major histocompatibility complex (MHC) class I-peptide complexes on the target cell. In the normal central nervous system, expression of MHC molecules is very low but often increases during inflammation. We set out to precisely define which central nervous system cells express MHC molecules in vivo during infection with a strain of murine hepatitis virus that causes a chronic, inflammatory demyelinating disease. Using double immunofluorescence labeling, we show that during acute infection with murine hepatitis virus, MHC class I is expressed in vivo by oligodendrocytes, neurons, microglia, and endothelia, and MHC class II is expressed only by microglia. These data indicate that oligodendrocytes and neurons have the potential to present antigen to T cells and thus be damaged by direct antigen-specific interactions with CD8+ T lymphocytes. (+info)
Schistosomal myeloradiculopathy due to Schistosoma mansoni: report on 23 cases.
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Schistosoma mansoni infection is likely to be responsible for a significant proportion of cases of myelopathy occurring in areas where schistosomiasis is endemic. The aim of this study is to describe the clinical, laboratory and therapeutic data of 23 patients with schistosomal myeloradiculopathy. The medical records of 23 patients with schistosomal myelopathy admitted to two general hospitals of Belo Horizonte (MG), in Brazil, from 1995 to 1999, were reviewed retrospectively. Seventeen patients were male (74%). The mean age for the whole group was 27 years. Lower limb weakness and associated lumbar and/or lower limb pain were reported by 20 patients (87%), and 16 (70%) were unable to walk. All individuals presented urinary retention and 19 (83%) complained of intestinal dysfunction. The treatment was based on the association of antischistosomal drugs and corticosteroids. Five patients (22%) presented a full response to treatment, 13 (57%) partial response without functional limitations and 4 (17%) partial improvement with limitations or no response. Three out of the 4 patients who stopped steroids before 45 days of treatment developed recurrence of the symptoms and signs of myelopathy. Our cases demonstrate the severe presentation of the disease and the data disclosed here suggest that treatment with steroids should be kept for months after clinical improvement. (+info)
Vertebral mass resulting from a chronic-contained rupture of an abdominal aortic aneurysm repair graft.
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We describe a case of a 63-year-old man with chronic-contained rupture of an abdominal aortic aneurysm at the site of prior graft repair of the aneurysm. Initially misinterpreted as osteomyelitis on the basis of CT findings, this chronic-contained rupture of the abdominal aorta eroding the vertebrae was preoperatively diagnosed at MR imaging and confirmed at surgery. A conventional angiogram failed to show the pseudoaneurysm. Owing to a major difference in the management of a contained aortic aneurysm rupture versus that for osteomyelitis, MR imaging with CT or MR angiography is recommended before any operative or invasive procedure. (+info)