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A J Steck

Publications and source records attributed to A J Steck.

At least 37 records · Page 2Linked to original sources
PubMed2000

Characterisation of autoantibodies to peripheral myelin protein 22 in patients with hereditary and acquired neuropathies.

To investigate the possibility that an autoimmune mechanism may play a role in the hereditary neuropathy Charcot-Marie-Tooth type 1A (CMT1A), sera were analysed by Western blot for anti-peripheral myelin protein 22 (PMP22) autoantibodies. These sera were compared with sera from patients with CMT type 2 (CMT2), acquired peripheral neuropathies such as chronic inflammatory demyelinating neuropathy (CIDP), anti-MAG IgM neuropathy, Miller-Fisher syndrome (MFS), diabetic neuropathy and with control blood donors. Anti-PMP22 positive sera were detected in 70% of patients with CMT1 and unexpectedly in 60% of patients with CMT2. Interestingly, 44% of the patients with other peripheral neuropathies and 23% of the apparently healthy controls showed also anti-PMP22 antibody reactivity. Immunohistochemical analysis of the human anti-PMP22 antisera on healthy sural nerve sections and on PMP22-expressing COS cells revealed that these sera did not recognise endogenous PMP22. Our results indicate that anti-PMP22 autoantibodies are found in sera of patients with different types of peripheral neuropathies, but their role in the pathogenesis of these diseases remains to be determined.

Adult↗
PubMed2000

[Neurological complications of HIV infection. Review: new diagnostic, therapeutic and prognostic aspects].

About one third of patients with HIV infection show neurological complications with considerable morbidity and high mortality. This is an actualized review of the most important neurological manifestations resulting from primary HIV infection, from secondary opportunistic infections, or as complications of antiretroviral therapy. The primary neurological manifestations, including HIV-associated dementia complex, myelopathies, peripheral neuropathies and myopathies, the more common opportunistic infections, primary central nervous system lymphoma and cerebrovascular diseases, are discussed in the light of new evidence in diagnosis, therapy and prognosis. Cognitive and psychiatric symptoms, visual changes, headache, seizures, dizziness, involuntary movements, gait disturbances, cranial neuropathies and focal deficits are the common neurological symptoms in HIV infection which are described under the aspect of differential diagnosis. It is important to bear in mind that nearly all information available to date on this subject concerns HIV patients in the period before combination therapies (including protease inhibitors). The introduction of highly active antiretroviral therapy (HAART) with protease inhibitors in 1995, and non-nucleoside reverse transcriptase inhibitors, have opened up new therapeutic modalities with a new emphasis on earlier detection and treatment of neurological complications. The prognosis of different HIV-associated neurological diseases has considerably improved, as recently shown in the case, for example, of progressive multifocal leucoencephalopathy.

AIDS Dementia Complex↗
PubMed2000

Diagnosis and treatment of intravascular lymphomatosis.

OBJECTIVE: To describe a patient with unusually good outcome of a rare, high-grade lymphoma that often involves the nervous system. DESIGN: Case report. SETTING: University hospital. CASE: A 70-year-old pharmacist first presented with meningoencephalitislike symptoms and 6 months later with acute confusional state followed by complex partial status epilepticus. Diagnosis of intravascular lymphomatosis was made using detection and biopsy of a bilateral adrenal tumor. MAIN OUTCOME AND RESULTS: Polychemotherapy consisting of CHOP (cyclophosphamide, doxorubicin hydrochloride, vincristine sulfate, and prednisone) led to complete remission. The patient's survival time currently exceeds 21/2 years. CONCLUSIONS: The possibility of intravascular lymphomatosis should be considered in adult patients with unclear meningoencephalitic syndrome, acute confusional state, dementia, or other unexplained neurologic conditions with signs of a systemic disease. In intravascular lymphomatosis, as in other high-grade non-Hodgkin lymphomas, CHOP polychemotherapy should be the standard treatment.

Aged↗
PubMed2000

Polyneuropathy attributes: a comparison between patients with anti-MAG and anti-sulfatide antibodies.

Thirty-two patients with a peripheral neuropathy and paraproteinemia were tested for IgM antibodies against myelin-associated protein (MAG) and sulfatide by means of enzyme-linked immunosorbent assay. Nine patients (28 %) had increased anti-sulfatide IgM antibodies and showed a chronic, slowly progressive, distally pronounced, and symmetric polyneuropathy with sensory to sensory-motor impairment, ataxia, hyporeflexia, and axonal involvement in electrophysiological studies. Ten patients (31 %) with increased anti-MAG antibodies had a similar, homogeneous polyneuropathy syndrome but presented with demyelinating features. A weak cross-reactivity between anti-MAG and anti-sulfatide antibodies was present in only three patients. In conclusion, although the two neuropathy groups clearly differed in their electrophysiological features, their clinical presentation was rather similar.

Aged↗
PubMed2000

Auto-antibody tests in peripheral neuropathies: pros and cons.

Most inflammatory neuropathies, both acute and chronic, probably result from an immune attack against antigens of the peripheral nervous system. Specific antibodies in serum that react with the peripheral nervous system have been described in a number of inflammatory neuropathies. We review the pathophysiological significance of auto-antibodies and discuss their use for the diagnosis of patients with peripheral neuropathy.

Ataxia↗
PubMed2000

Auditory agnosia and auditory spatial deficits following left hemispheric lesions: evidence for distinct processing pathways.

Auditory recognition and auditory spatial functions were studied in four patients with circumscribed left hemispheric lesions. Patient FD was severely deficient in recognition of environmental sounds but normal in auditory localisation and auditory motion perception. The lesion included the left superior, middle and inferior temporal gyri and lateral auditory areas (as identified in previous anatomical studies), but spared Heschl's gyrus, the acoustic radiation and the thalamus. Patient SD had the same profile as FD, with deficient recognition of environmental sounds but normal auditory localisation and motion perception. The lesion comprised the postero-inferior part of the frontal convexity and the anterior third of the temporal lobe; data from non-human primates indicate that the latter are interconnected with lateral auditory areas. Patient MA was deficient in recognition of environmental sounds, auditory localisation and auditory motion perception, confirming that auditory spatial functions can be disturbed by left unilateral damage; the lesion involved the supratemporal region as well as the temporal, postero-inferior frontal and antero-inferior parietal convexities. Patient CZ was severely deficient in auditory motion perception and partially deficient in auditory localisation, but normal in recognition of environmental sounds; the lesion involved large parts of the parieto-frontal convexity and the supratemporal region. We propose that auditory information is processed in the human auditory cortex along two distinct pathways, one lateral devoted to auditory recognition and one medial and posterior devoted to auditory spatial functions.

Aged↗
PubMed2000

Long-term follow-up after extracranial internal carotid artery dissection.

OBJECTIVE: To evaluate long-term outcome after extracranial internal carotid artery dissection (eICAD) in consideration of the applied antithrombotic therapy. MATERIAL AND METHODS: Among 33 consecutive eICAD patients initially treated either with anticoagulation (n = 25) or with antiplatelets (n = 8), a standardized interview was performed after 28 +/- 22.1 months to analyze risks and benefits of both agents. Ischemic and hemorrhagic complications, occurrence of seizure and rates of arterial recanalization were compared and long-term clinical outcome was assessed using the modified Rankin Scale (mRS) and Barthel Index (BI). RESULTS: Among anticoagulated patients, 1 died due to brain herniation. In 3 patients stroke (n = 2) or TIA (n = 1) recurred. In the antiplatelet group, none died and no subsequent ischemic events happened. Hemorrhagic complications were noted in neither treatment group. Functional outcome among anticoagulated patients was BI 92 +/- 21.6 and mRS 1.48 +/- 1.50, which did not differ from patients initially treated with antiplatelets (BI 89 +/- 18.9, mRS 1.50 +/- 1.41, p > 0.05). Four anticoagulated patients developed seizures, compared to 2 patients with antiplatelets (p > 0.05). Arterial recanalization occurred in 16 of 22 antico- agulated patients with ultrasound follow-up, compared to 6 of 6 patients with antiplatelets (p > 0.05). CONCLUSION: In the absence of iatrogenic side effects, both anticoagulation and antiplatelets seem to be safe for eICAD. The rates for death and stroke were low and outcome ratings did not differ between both agents. These findings may indicate that a controlled randomized trial comparing anticoagulation and antiplatelets is ethically justified.

Adult↗
PubMed1999

[Multiple sclerosis: epidemiology, molecular pathology and therapy].

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system. It results from an autoimmune response against one of several antigens of cerebral white matter tissue. The pathogenesis of MS lesions consists in migration of auto-reactive T-cells and disruption of the blood-brain-barrier. B-cells and their products are, however, also important for demyelination together with various cytotoxic or pro-inflammatory cytokines. Recent advances in immunology and biotechnology and protein engineering techniques have opened the door for novel immunotherapies. Immune modulation with beta-interferon has shown beneficial effect, both in relapsing remitting and secondary progressive multiple sclerosis.

B-Lymphocytes↗
PubMed1999

[Cerebellar syndrome after varicella infection without virus identification in cerebrospinal fluid--an important differential ataxia diagnosis].

We report on a 35 year old female with a 26 day history of an intermittent cerebellar syndrome (dysarthria, ataxia of extremities, gait and trunk, nystagmus), mild meningism, cephalgia, recurrent emesis and nausea. Symptoms developed after typically chickenpox exanthema. Examination of the liquor showed mild pleocytosis, elevated protein and increased albumin quotient. Virus was not found by EIA or PCR. There were elevated levels of IgM- and IgG-antibodies to VZV. The EEG showed mild general changes, compatible with an encephalitis. Neuroradiological examinations were unremarkful. The neurological deficits partly regressed in the follow-up of two months. To the best of our knowledge we are the first that describe the paradox of an intermittent cerebellar syndrome after infection with chickenpox without detection of the virus in the liquor. This phenomenon can be related to the unusual combination of cerebellar ataxia and the later occurrence of mild encephalitis.

Adult↗
PubMed1999

[Intermittent paraparesis as manifestation of a bilateral chronic subdural hematoma].

Chronic subdural haematomas are mainly related to slight or moderate head trauma with consecutive lesion of bridge or cortical veins and bleeding in the subdural space. Further predisposing factors are known impairment of coagulation (coagulopathies, treatment with anticoagulants, alcohol abuse), risk factors for degenerative disease of the arteries (diabetes mellitus, arterial hypertension), and development of pressure gradients (hydrocephalus, epileptic seizures, lumbar puncture, CSF drainage and cerebral atrophy). Chronic subdural haematomas appear bilaterally in 20 to 25% of cases. We report on a 69-year-old male with a 4-day history of intermittent, proximal, painless paraparesis (BMA grade M2-5) without a trigger event. Sensibility was normal in all qualities and vigilance was not disturbed. Computed tomography of the neurocranium revealed a bitemporally located chronic subdural haematoma with extension to parietal on both sides. Trepanation was performed over the tuber parietale and temporoparietally on both sides, with release of 150 ml fluid. The neurologic deficits regressed totally within 12 hours postoperatively. To the best of our knowledge, we are the first to describe the clinical paradox of intermittent, painless paraparesis with preserved sensibility and without disturbances of vigilance, as manifestation of a chronic subdural haematoma possibly leading to impairment of cerebral blood flow in the area of the middle cerebral artery. Small changes in systemic blood pressure lead to changes in cerebral perfusion pressure due to vessel compression by the haematoma, thus explaining the intermittent character of the clinical presentation.

Aged↗
PubMed1999

Matrix metalloproteinase upregulation in chronic inflammatory demyelinating polyneuropathy and nonsystemic vasculitic neuropathy.

OBJECTIVE: To determine the expression pattern and cellular source of matrix metalloproteinases (MMPs) in chronic inflammatory demyelinating polyneuropathy (CIDP) and nonsystemic vasculitic neuropathy (NSVN). BACKGROUND: MMPs are endopeptidases involved in tissue destruction and infiltration by immune cells in multiple sclerosis and Guillain-Barré syndrome. Enzyme inhibitors of MMPs attenuate clinical symptoms in corresponding animal models of these diseases. MMP inhibition may therefore be a novel approach for the treatment of CIDP and NSVN. However, the spectrum of MMPs expressed in chronic inflammatory neuropathies has not been established. METHODS: The expression of MMP-2, MMP-3, MMP-7, and MMP-9 in T cells, macrophages, and stromal cells in CIDP, NSVN, and noninflammatory neuropathies (NIN) was quantitated by immunohistochemistry. Results were correlated with clinical and electrophysiologic findings. RESULTS: The production of MMP-2 and MMP-9 is increased in nerve tissue in CIDP and NSVN compared with NIN. T cells are the predominant source of MMP-2 and MMP-9 in CIDP and NSVN, whereas macrophages contribute only to a minor extent. Stromal cells of the perineurium/epineurium are an additional source of MMP-2 in NSVN, but not in CIDP. Expression of MMP-3 and MMP-7 was not detectable in CIDP or NSVN. Expression of MMP-2 and MMP-9 did not correlate with clinical disease activity and electrophysiologic measurements. CONCLUSIONS: The upregulation of MMP-2 and MMP-9 is a specific feature of CIDP and NSVN, and selective inhibitors of these enzymes could be used to prevent inflammatory tissue damage. The similar increase of MMP-2 and MMP-9 in both demyelinating (CIDP) and nondemyelinating (NSVN) neuropathies raises doubts about whether MMPs play a primary role in demyelination.

Adult↗
PubMed1999

Anti-MAG IgM penetration into myelinated fibers correlates with the extent of myelin widening.

The purpose of this study was to evaluate the relationship between immunoglobulin M (IgM) antibodies penetration into myelinated peripheral nerve fibers and the widening of the peripheral myelin sheaths in anti-myelin-associated glycoprotein (anti-MAG) demyelinating IgM monoclonal polyneuropathy. Demyelinating polyneuropathy with monoclonal IgM is often associated with anti-MAG autoantibodies, which are thought to initiate the disease with IgM deposits usually present on the myelin sheaths. We analyzed nerve biopsies from 12 patients with an anti-MAG demyelinating neuropathy by confocal and electron microscopy. The total number of nerve fibers and the proportion of IgM-associated fibers were quantified after immunohistochemical staining. The affinities of IgM were examined by analyzing the binding pattern of serum IgM on normal peripheral nerve sections. Ultrastructural examinations of the biopsies showed a good correlation between in situ widened myelin sheaths and the IgM penetration level into myelinated fibers. The terminal complement complex appears not be involved in the penetration of IgM into the myelinated fibers. Our findings suggest a causative role of the IgM anti-MAG antibodies in the ultrastructural modifications of the myelin sheaths. The basement membrane and myelin components appear to be the major targets of the IgM monoclonal antibodies. However, the pathogenic mechanism whereby IgM antibodies reach their targets and induce nerve damage are still unclear.

Fluorescent Antibody Technique↗
PubMed1999

Epilepsia partialis continua: a new manifestation of anti-Hu-associated paraneoplastic encephalomyelitis.

We report on 3 anti-Hu-positive patients who presented with clinical and electroencephalographic (EEG) features of epilepsia partialis continua (EPC). Two of the patients had an associated small cell carcinoma. Magnetic resonance imaging (MRI) disclosed a hyperintense nonenhancing focal lesion in T2-weighted images in the sensorimotor area in 2 patients. Histopathological analysis of the lesion revealed inflammatory infiltrates and neuronal cell loss. In the patient who had a postmortem study, these neuropathological changes were not observed in other areas of the nervous system. This study emphasizes that the possibility of an anti-Hu-associated paraneoplastic disorder must be considered in patients with cortical encephalitis presenting with EPC when a brain tumor can be excluded.

Adult↗
PubMed1999

Paraproteinaemic neuropathies.

In this article, we review the main clinical and pathological features of paraproteinaemic neuropathies and discuss recent experimental findings. Further knowledge of the disease process at the molecular level has allowed a better characterization of clinical syndromes and has given new insights into their pathogenesis. The most convincing evidence for a causal relationship can be drawn from IgM monoclonal gammopathies with specificities directed against carbohydrate determinants of the myelin associated glycoprotein (MAG). There remain however, many unresolved questions, such as how monoclonal anti-MAG IgM antibodies cross the blood-nerve barrier and trigger a chronic demyelinating polyneuropathy while the central nervous system is essentially spared. IgM paraproteins with specificity for other molecules, such as neurofilaments, sulphatide, gangliosides, chondroitin sulphate and tubulin, have also been identified, but their pathogenetic importance remains to be elucidated. Other paraproteinaemic neuropathies such as IgG and IgA neuropathies have to be considered separately. The paraneoplastic endocrine and cytokine manifestations of rare osteosclerotic myelomas provide valuable insights into the interaction between the immune and the nervous system. The antigen-specificity of IgG and IgA monoclonal antibodies are only poorly characterized but some have been found to be directed against endoneurial determinants and a few against axonal proteins such as neurofilaments.

Demyelinating Diseases↗