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Biomedical subjects

M Neveling

Publications and source records attributed to M Neveling.

At least 19 recordsLinked to original sources
PubMed2006

Primary stroke unit treatment followed by very early carotid endarterectomy for carotid artery stenosis after acute stroke.

BACKGROUND: Although it is recognized that carotid endarterectomy (CEA) is the treatment of choice in symptomatic internal carotid artery (ICA) stenosis, in the past, very early CEA has been shown to carry substantial risks. We assessed an interdisciplinary concept of very early CEA in patients with high-grade (>70%) symptomatic ICA stenosis at a single center. PATIENTS AND METHODS: The course of treatment and outcomes of patients who underwent CEA as early as possible after being referred to the stroke unit for symptoms of transient ischemic attack and stroke were prospectively evaluated, including the following parameters: age, severity of ischemia-related symptoms according to the modified Rankin scale, duration of symptoms until admission, multimodal imaging findings (color-coded duplex, cranial computed tomography, magnetic resonance imaging, positron emission tomography), duration until CEA, perioperative course and complications, as well as duration of in-hospital care. RESULTS: Fifty consecutive patients (median age 68 years, range 44-90) with clinical and imaging signs of transient ischemic attack (n = 19) or stroke (n = 31) were included from January 2000 until December 2004. All except 1 patient showed a preoperative Rankin < 4. There was a median time period of 6 h between the onset of symptoms and admission (range 1 h to 15 days) and a median duration of 4 days after admission until operation (range 1-21 days). Seven patients underwent CEA of the contralateral, severely stenosed ICA after symptomatic ipsilateral ICA occlusion. Four out of 5 patients who primarily underwent systemic thrombolysis recovered almost completely. Three patients (6%) experienced a clinical deterioration before surgery. In the majority of patients (43/50), CEA was performed under local anesthesia with selective shunt use which became necessary in 26%. Three patients (6%) had postoperative worsening due to new infarcts. In 2 cases, an intracerebral hemorrhage occurred, of which 1 remained asymptomatic. In 1 case, surgical revision was necessary because of an ICA thrombosis without permanent neurological decline. Patients were discharged after a median time of 14.5 days (range 4-44). CONCLUSIONS: After careful selection and preparation in a stroke unit, patients with acute stroke due to carotid stenosis can undergo very early CEA under local anesthesia with a perioperative risk comparable with the risk of later endarterectomy, therefore preventing very early stroke recurrences.

Adult↗
PubMed2006

Autologous blood stem cell transplantation in refractory systemic lupus erythematodes with recurrent longitudinal myelitis and cerebral infarction.

Autologous hematopoietic stem cell transplantation (ASCT) has the potential to eliminate autoreactive lymphocytes and may represent a therapeutic option for patients with refractory autoimmune diseases. We describe a 19-year old woman with neuropsychiatric systemic lupus erythematodes (NPSLE) presenting with acute longitudinal myelitis and aseptic meningitis. Despite therapy with methylprednisolone and cyclophosphamide (CYC), recurrence of longitudinal myelitis and a disabling stroke-like relapse occurred. Hematopoietic stem cells were mobilized by CYC at 2 g/m2 and G-CSF. The patient was conditioned by CYC at 200 mg/kg and anti-thymocyte globulin and 3.6 x 10(6) CD34+ cells/kg were infused. Hematopoietic regeneration was observed on day 12 after ASCT. Currently, 18 months after ASCT, the patient is in clinical remission with no evidence for residual serological or neuroradiological activity of SLE. Although a longer follow-up will be needed to reliably assess the efficacy of ASCT in this patient, the present case demonstrates that ASCT may represent a therapeutic option for patients with severe NPSLE.

Adult↗
PubMed2004

Which time-to-peak threshold best identifies penumbral flow? A comparison of perfusion-weighted magnetic resonance imaging and positron emission tomography in acute ischemic stroke.

BACKGROUND AND PURPOSE: In acute ischemic stroke, the hypoperfused but viable tissue is the main therapeutic target. In clinical routine, time-to-peak (TTP) maps are frequently used to estimate the hemodynamic compromise and to calculate the mismatch volume. We evaluated the accuracy of TTP maps to identify penumbral flow by comparison with positron emission tomography (PET). METHODS: Magnetic resonance imaging (MRI) and PET were performed in 11 patients with acute ischemic stroke (median 8 hours after stroke onset, 60 minutes between MRI and PET imaging). The volumes defined by increasing TTP thresholds (relative TTP delay of >2, >4, >6, >8, and >10 seconds) were compared with the volume of hypoperfusion (<20 mL/100 g per min) assessed by 15O-water PET. In a volumetric analysis, each threshold's sensitivity, specificity, and predictive values were calculated. RESULTS: The median hypoperfusion volume was 34.5 cm3. Low TTP thresholds included large parts of the hypoperfused but also large parts of normoperfused tissue (median sensitivity/specificity: 93%/60% for TTP >2) and vice versa (50%/91% for TTP >10). TTP >4 seconds best identifies hypoperfusion (84%/77%). The positive predictive values increased with the size of hypoperfusion. CONCLUSIONS: This first comparison of quantitative PET-CBF with TTP maps in acute ischemic human stroke indicates that the TTP threshold is crucial to reliably identify the tissue at risk; TTP >4 seconds best identifies penumbral flow; and TTP maps overestimate the extent of true hemodynamic compromise depending on the size of ischemia. Only if methodological restrictions are kept in mind, relative TTP maps are suitable to estimate the mismatch volume.

Adult↗
PubMed2003

[Periodic surveillance of nosocomial infections in two neurology intensive care units. A valuable tool for quality management in intensive care].

BACKGROUND AND OBJECTIVE: Nosocomial infections are a common problem in intensive care therapy and have relevant influence on morbidity, mortality and associated costs. The aim of this study was to assess data on the epidemiology of nosocomial infections and related risk factors in neurological intensive care patients and to use them for internal quality management. METHODS: Prospective periodic surveillance was performed in the first quarter of the years 1999 and 2000 in two neurology intensive care units. RESULTS: Within the surveillance period, 340 patients with 2443 patient days and a mean length of stay 7,6 days were enrolled. A total of 63 nosocomial infections were identified in 51 patients. In comparison with national reference data, device utilisation rates as well as device-associated nosocomial infection rates were on a higher level. By timely and interpretative feedback of the surveillance data, for the first time the unit-specific nosocomial infection situation was made clear for the ward staff. As a result, different quality management activities like establishment of evidence-based infection control guidelines, continuous surveillance for pneumonia and optimisation of empirical antibiotic therapy were initiated in both units. CONCLUSION: The establishment of periodic surveillance proved to be a valuable tool for the promotion of quality management activities in both intensive care units.

Anti-Bacterial Agents↗
PubMed2002

Feasibility of source images of computed tomographic angiography to detect the extent of ischemia in hyperacute stroke.

BACKGROUND AND PURPOSE: Computed tomographic angiography (CTA) is suggested to be a promising tool for patient selection for thrombolytic therapy of acute stroke. It does not only provide information on intracranial vasculature, but also on the capacity of the collateral circulation and the pattern of poorly perfused brain tissue. The objective of our study was to evaluate whether the presence and size of critically hypoperfused tissue assessed with flow positron emission tomography (PET) as a gold standard can reliably be identified on CTA source images. METHODS: Fifteen potential candidates for early thrombolysis underwent CTA 65-170 min (mean 107 min) after the onset of acute anterior circulation stroke. Regional cerebral perfusion was measured between 27 and 86 min (mean 59 min) later with [(15)O]-H(2)O and PET, and the volume of critically hypoperfused cortical tissue was assessed. CTA source images were evaluated by a neuroradiologist and an experienced stroke neurologist. The patients were classified into three groups according to the presumed size of the perfusion deficit on CTA (large, small, no perfusion deficit). RESULTS: PET revealed the presence of critical cortical hypoperfusion in 10 patients, 5 had no critical cortical hypoperfusion. The neuroradiologist correctly identified the presence of a perfusion deficit in all patients, the neurologist had two false negative and one false positive ratings. Concerning the size of the perfusion deficit, there was considerable inaccuracy in both raters. CONCLUSIONS: The usefulness of CTA source images in yielding information about the perfusion state of stroke patients in clinical routine should not be overestimated.

Adult↗
PubMed2001

Intravenous thrombolysis in proximal middle cerebral artery occlusion.

Subgroup analyses of data from an open-label study of intravenous recombinant tissue plasminogen activator (rt-PA) administered to stroke patients were performed. Clinical outcome and incidence of intracranial hemorrhage were evaluated in 20 patients diagnosed by transcranial Doppler ultrasound as having proximal middle cerebral artery (MCA) occlusion. Additionally early infarct signs and size of final infarction were assessed. A favorable outcome (mRS 0-2) was seen in 30% of all patients. The incidence of symptomatic intracranial hematoma (10%) in patients with proximal MCA occlusion was higher than the overall hemorrhage rate of intravenous rt-PA treatment, but comparable to the data on intra-arterial thrombolysis in this stroke subgroup. All patients except 1 developed ischemic infarction in the MCA territory. Intravenous rt-PA treatment within 3 h may also be effective in patients with proximal MCA occlusion. The risk of intracerebral hematoma does not seem to be greater than in intra-arterial thrombolysis.

Aged↗
PubMed2001

Predictive value of neurochemical monitoring in large middle cerebral artery infarction.

BACKGROUND AND PURPOSE: Space-occupying brain edema is a life-threatening complication in patients with large hemispheric stroke. Early identification of patients at risk is necessary to decide on invasive therapies such as decompressive hemicraniectomy or hypothermia. To assess potential predictors of malignant brain edema by measurement of intracranial pressure (ICP) and microdialysis in patients with large hemispheric stroke and different clinical course. METHODS: In an ongoing prospective clinical study, an ICP and microdialysis probe were placed into the parenchyma of the ipsilateral frontal lobe of 10 patients. Extracellular concentrations of glutamate, lactate, pyruvate, and glycerol were measured continuously. Repeated cranial CT scans were scrutinized for size of infarction and presence of mass effect. RESULTS: The dynamics of the different substances varied in accordance with the clinical course, size of infarction, and local brain edema: Increase in ICP and in glutamate concentration and lactate-pyruvate ratio was followed by massive edema and large infarcts; generally low and stable ICP and substrate concentrations were found in patients without progressive space-occupying infarcts. CONCLUSIONS: In patients with large hemispheric infarction, bedside monitoring with microdialysis is feasible and might be helpful together with ICP recording to follow the development of malignant brain edema.

Adult↗
PubMed2000

MRA in patients with cerebrovascular disease. Considerations of clinical effectiveness.

OBJECTIVE: To establish in which clinical contexts cerebral MR angiography (MRA) is routinely carried out in a neurological university department and to describe its clinical impact. MATERIAL AND METHODS: Medical records, reports of findings and documentation of imaging examinations carried out in all 69 patients referred to the Department of Radiology from the Department of Neurology between 1995 and 1998 for cerebral MRA were evaluated. The clinical impact of all imaging findings was assessed on the basis of the medical records. RESULTS: Circulatory disturbances in the vertebrobasilar arteries (n = 34) were the most frequent indication for investigation. MRA followed CT or duplex sonography in 66 of the 69 patients with a mean delay of 8 days. MRA was considered diagnostically inferior to conventional MR in 11 cases, comparable in 30 and superior in 25. Comparing MRA and duplex sonography, the corresponding figures were 12, 29 and 23. In retrospect, 56 MRAs were judged unnecessary. CONCLUSION: Controlled clinical studies on optimal use of MRA are needed to avoid wasting resources and to exploit the method's full diagnostic potential in appropriate cases.

Adult↗
PubMed1999

[Hypokalemic paralysis in furosemide therapy and simultaneous laxative abuse].

BACKGROUND: Clinical signs of hypokalemia are not directly related to the extent of the electrolyte imbalance, and therefore monosymptomatic cases may be observed. CASE REPORT: Following an acute gastroenteritis with considerable diarrhea, a 47-year-old male patient was admitted to hospital for progressive painful paraparesis. Upon admission, the patient complained of painful paresthesias in both legs, and a moderate flaccid paraparesis with widespread fasciculations and loss of leg tendon reflexes was found. Serum potassium level on admission was 1.7 mmol/l. Other signs of hypokalemia were absent, and the ECGs showed a slow sinus rhythm without disturbances of de- or repolarisation or cardiac arrhythmias. Hypokalemic paralysis was diagnosed and was considered to be primarily drug-induced, as the patient had a history of laxative abuse and was on a continuous medication with furosemide (80 mg/d) without regular assessment of serum electrolytes. The additional electrolyte loss following the gastroenteritis precipitated the development of clinical signs of hypokalemia. In parallel to the rise in serum potassium levels, both painful paresthesias and muscle weakness disappeared, and electromyography documented the amelioration of the myopathic syndrome. CONCLUSION: The prominent clinical symptom of hypokalemia was a dyskalemic paralysis in the absence of other sequelae of electrolyte imbalance, such as cardiac arrhythmias or vegetative disturbances.

Cathartics↗
PubMed1999

Stroke following internal carotid artery occlusion - a contra-indication for intravenous thrombolysis?

Between March 1996 and December 1997, 15 consecutive patients with carotid artery occlusion diagnosed with duplex sonography were treated with intravenous recombinant tissue plasminogen activator (rt-PA), following a protocol similar to that of the National Institute of Neurological Disorders and Stroke (NINDS) study. On the basis of ultrasound findings, six of the 15 patients had internal carotid artery dissection (ICD), and the remaining nine had atherothrombotic internal carotid artery (ICA) occlusion. No relevant haemorrhagic complications were observed after rt-PA treatment of ICA occlusion. Excellent late functional outcome was observed in three of the 15 patients with ICA occlusion, moderate and poor outcome in four patients. Four patients died, and mortality was related to stroke severity upon admission. A good outcome seemed to be more likely in the small group of patients with ICD, than in the patients suffering atherothrombotic ICA occlusion. As the results of rt-PA treatment in this case series are by no means devastating, our data do not corroborate the hypothesis that patients with acute ischemic stroke following ICA occlusion should a priori be excluded from intravenous thrombolysis. The possible benefit of rt-PA treatment in stroke following acute or chronic ICA occlusion should be assessed in a larger prospective trial, for which this case series might serve as a pilot study.

Adult↗
PubMed1998

[Protracted course of bromazepam poisoning in advanced age].

HISTORY AND CLINICAL FINDINGS: A 68-year-old woman was found unconscious and hardly breathing. Artificial ventilation was undertaken by an emergency physician who brought her to hospital. Physical examination provided no evidence of relevant organ abnormalities. Neurological examination of the comatose patient revealed absent brain-stem reflexes and spontaneous respiration. But no other focal neurological abnormalities were found. INVESTIGATIONS: Routine laboratory tests, ECG, chest radiogram, Doppler sonography of arteries to the brain, lumbar cerebrospinal fluid and computed tomography of the skull were unremarkable. Toxicological tests discovered bromazepam intoxication (serum level 6 mg/l; maximal serum level after intake of 6 mg of the active constituent: 0.1 mg/dl). DIAGNOSIS, TREATMENT AND COURSE: When bromazepam poisoning was demonstrated elimination of the drug was no longer feasible; the spontaneous course of the poisoning with slowly falling drug levels could thus be observed over 10 days. In parallel with the fall of bromazepam concentration in blood, restitution of breathing and of brain-stem reflexes was recorded until, 12 days after intake of the drug, normal functions had been restored. CONCLUSION: Central respiratory arrest occurred at a bromazepam serum level of 6 mg/l. Without intensive medical care the patient would not have survived.

Aged↗
PubMed1998

Early intravenous thrombolysis with recombinant tissue-type plasminogen activator in vertebrobasilar ischemic stroke.

BACKGROUND: The optimal therapy of vertebrobasilar ischemic stroke is under debate. In the case of underlying basilar artery occlusion, intra-arterial thrombolysis is recommended. Because this pathologic condition is rarely found and the procedure is time consuming and restricted to specialized centers, the question arises whether early intravenous thrombolysis could also effectively be applied in vertebrobasilar ischemic stroke. OBJECTIVE: To determine if early intravenous thrombolysis could be used effectively in vertebrobasilar ischemic stroke. DESIGN: A case series of 12 consecutive patients with acute vertebrobasilar ischemia were followed up 3 months after thrombolytic treatment at the Department of Neurology of the University Hospital of Cologne, Cologne, Germany, a primary care and referral center. METHODS: Patients with clinically diagnosed moderate to severe vertebrobasilar ischemic stroke with clearly determined symptom onset were treated with intravenous recombinant tissue-type plasminogen activator within 3 hours after symptom onset following a protocol similar to that of the National Institute of Neurological Disorders and Stroke study. RESULTS: On admission, 7 patients exhibited moderate to severe brainstem symptoms without impairment of consciousness and 5 patients had impairment of consciousness, of whom 2 were comatose. Of 12 patients, 10 had a favorable outcome after 3 months defined as full independence (Barthel index score of 100) or return to premorbid condition. One patient had a poor outcome with complete dependency due to reocclusion after primarily successful thrombolysis, and 1 patient died of severe brainstem infarction and additional space occupying parietal hemorrhage. CONCLUSION: Favorable outcome could be achieved in the majority of 12 consecutive patients with moderate to severe vertebrobasilar ischemic stroke treated with intravenous recombinant tissue-type plasminogen activator within 3 hours after symptom onset.

Acute Disease↗
PubMed1998

Potential pitfalls in apnea testing.

To determine the influence of baseline paCO2 on the results of apnea testing in the diagnosis of brain death, we performed an open prospective study on 36 patients fulfilling all other criteria for the diagnosis of brain death according to the criteria proposed by the Advisory Board of the German Federal Chamber of Physicians. For testing of apnea, patients underwent hypoventilation with 100% oxygen supply until a baseline paCO2 of 40 torr (5.3 kPa, n = 24, group 1) or 60 torr (8.0 kPa, n = 12, group 2) was reached. Then, patients were disconnected from the ventilator and apneic oxygenation with insufflation of 61 O2/min into the tracheal cannula was performed for five minutes. Arterial blood gas samples were obtained every minute during the testing period. In parallel, patients were observed for signs of spontaneous breathing. All patients remained apneic during the five minute test period. No relevant hypoxia (paO2 < 80 torr [10.6 kPa]) was observed in either group. In group 1, a mean baseline paCO2 of 45 torr (6.0 kPa) was registered, mean end-paCO2 was 75 torr (10.0 kPa). In group 2, paCO2 values were 66 torr (8.8 kPa) and 90 torr (12 kPa), respectively. Baseline pH in group 1 (7.32) decreased to 7.18 at the end of testing and from 7.23 to 7.13 in group 2. Patients in group 2 were in possible danger of developing a CO2-induced narcosis mimicking apnea. Secondary organ damage due to severe respiratory acidosis could not be excluded in the patients of group 2. As no complications were observed in group 1 and apnea was evident in all these patients, we consider a baseline paCO2 of 40 torr (5.3 kPa) sufficient to establish apnea after five minutes of apneic oxygenation if an increase of baseline paCO2 of at least 20 mmHg is documented by arterial blood gas sampling. A higher baseline paCO2 may endanger patients without yielding more specific testing results.

Apnea↗
PubMed1998

Alterations of neuropsychological function and cerebral glucose metabolism after cardiac surgery are not related only to intraoperative microembolic events.

BACKGROUND AND PURPOSE: High-intensity transient signals (HITS) during cardiac surgery are capable of causing encephalopathy and cognitive deficits. This study was undertaken to determine whether intraoperative HITS cause alterations of neuropsychological function (NPF) and/or cerebral glucose metabolism (CMRGlc), even in a low-risk patient group, and whether induced changes are interrelated. METHODS: Eighteen patients without signs of cerebrovascular disease underwent elective coronary artery bypass grafting (CABG), and two of these additionally underwent valve replacement in normothermia. Intraoperatively, HITS were recorded by means of transcranial Doppler ultrasonography (TCD). Perioperatively, NPF and CMRGlc were assessed using a standardized complex test battery and positron emission tomography with 18F-2-fluoro-2-deoxy-D-glucose (FDG-PET), respectively. RESULTS: Intraoperatively, the number of HITS ranged from 90 to 1710 per patient and hemisphere, more on the right side than on the left (P<.05). HITS occurred primarily during cardiopulmonary bypass (71.3%) and, to a lesser extent, during aortic manipulation (22.2%). Changes in global and regional CMRGlc between first (one day preoperatively) and second (8 to 12 days postoperatively) FDG-PET scans were mild. No correlations were found between the number of HITS, age of patient, duration of cardiac ischemia or cardiopulmonary bypass and the changes in CMRGlc. In patients with recorded HITS and a postoperative decrease of regional CMRGlc (n=11), the maximal decrease of rCMR Glc in each hemisphere below the individual global change of CMRGlc correlated with the number of HITS (r= -0.46, P<.05). Limitations in NPF occurred 8 to 12 days postoperatively, resolved within 3 months, and were not found to be correlated to the absolute number of HITS or changes in CMRGlc. CONCLUSIONS: HITS during cardiac surgery can cause alterations of both NPF and CMRGlc, even in a low-risk patient group. However, the number of HITS and changes in NPF and CMRGlc are not necessarily interrelated, which indicates that (1) the location of brain damage related to HITS is more important for the development of NPF than is the absolute number of HITS, and (2) factors in addition to HITS might contribute to surgery-related brain damage.

Adult↗
PubMed1998

Early intravenous thrombolysis for acute ischemic stroke in a community-based approach.

BACKGROUND AND PURPOSE: Controlled multicenter studies have demonstrated the efficacy of systemic recombinant tissue-type plasminogen activator (rtPA) treatment in selected cases of acute ischemic stroke. The feasibility of this therapeutic option in clinical practice was assessed in a community-based approach. METHODS: We offered rtPA treatment to stroke patients in a prospective open-label monocenter study applying inclusion criteria similar to those of the National Institute of Neurological Disorders, and Stroke study. In order to treat patients within 3 hours of symptom onset, a referral system was used by which eligible patients from all over the city of Cologne, Federal Republic of Germany, were rushed to the Department of Neurology of the University Hospital. We present data on the effectiveness of the referral system and the outcome results of the first 100 consecutive patients treated within an 18-month period. RESULTS: Of 453 consecutive patients with a presumed diagnosis of acute stroke referred to our department between March 1996 and August 1997, 100 patients (22%) were treated with intravenous thrombolysis, 26% of them within 90 minutes of symptom onset. The average time from stroke onset to arrival at our department was 78 minutes, and from arrival to treatment 48 minutes. After 3 months, 53 patients recovered to fully independent function. The rates of total, symptomatic, and fatal intracerebral hemorrhage were 11%, 5%, and 1%, respectively. Overall mortality was 12%. CONCLUSIONS: Thrombolysis with rtPA was effectively applied in routine management of stroke patients in a community-based approach with acceptable efforts and without additional costs. Under these circumstances, outcome and complication rates were comparable to those of multicenter trials.

Academic Medical Centers↗
PubMed1997

MRI- and MRA-guided therapy of carotid and vertebral artery dissections.

A high sensitivity and specificity has been shown for magnetic resonance imaging (MRI) and angiography (MRA) in the diagnosis of internal carotid (ICAD) and vertebral (VAD) artery dissections, where arteriography has been and still is the gold standard. Five patients (three with ICAD, two with VAD; age range 42-56 years) are presented, in whom diagnosis and follow-up management were exclusively based on non-invasive measures. In all patients, MRI demonstrated a typical intramural hematoma and MRA in 3D phase contrast technique showed loss or diminished flow. After anticoagulation (heparin) for 3 to 4 weeks follow-up, MRI showed a regression of the mural hematoma and MRA revealed reperfusion or improvement of flow. Depending on the extent of MRI-/MRA-pathology, three patients were put on antiplatelet therapy and two on Coumadin until normalization of MRI and MRA findings, which are assessed in 3-months intervals. We suggest, that with, (I) a suspicious history, symptoms and signs for cervical artery dissection (CAD), (II) typical MR-findings proven to indicate CAD, (III) improving or resolving at follow-up, (IV) in unusual location for atherosclerotic involvement, (V) in the absence of coexisting atherosclerotic lesions, the diagnosis has not to be confirmed with conventional arteriography. Therefore, safe MRI- and MRA-guided anticoagulation and antiplatelet therapy during serial follow-up measurements are possible.

Adult↗