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1.
Pract Lab Med ; 26: e00236, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34041343

RESUMO

Background: Serum biomarker S100B has been explored for its potential benefit to improve clinical decision-making in the management of patients suffering from traumatic brain injury (TBI), especially as a pre-head computed-tomography screening test for patients with mild TBI. Although being already included into some guidelines, its implementation into standard care is still lacking. This might be explained by a turnaround time (TAT) too long for serum S100B to be used in clinical decision-making in emergency settings. Methods: S100B concentrations were determined in 136 matching pairs of serum and lithium heparin blood samples. The concordance of the test results was assessed by linear regression, Passing Pablok regression and Bland-Altman analysis. Bias and within- and between-run imprecision were determined by a 5 × 4 model using pooled patient samples. CT scans were performed as clinically indicated. Results: Overall, S100B levels between both blood constituents correlated very well. The suitability of S100B testing from plasma was verified according to ISO15189 requirements. Using a cut-off of 0.105 ng/ml, a sensitivity and negative predictive value of 100% were obtained for identifying patients with pathologic CT scans. Importantly, plasma-based testing reduced the TAT to 26 min allowing for quicker clinical decision-making. The clinical utility of integrating S100B in TBI management is highlighted by two case reports. Conclusions: Plasma-based S100B testing compares favorably with serum-based testing, substantially reducing processing times as the prerequisite for integrating S100B level into management of TBI patients. The proposed new clinical decision algorithm for TBI management needs to be validated in further prospective large-scale studies.

2.
Cerebrovasc Dis ; 50(3): 347-355, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33730735

RESUMO

INTRODUCTION: Sodium MRI (23Na MRI) derived biomarkers such as tissue sodium concentration (TSC) provide valuable information on cell function and brain tissue viability and has become a reliable tool for the assessment of brain tumors and ischemic stroke beyond pathoanatomical morphology. Patients with major stroke often suffer from different degrees of underlying white matter lesions (WMLs) attributed to chronic small vessel disease. This study aimed to evaluate the WM TSC in patients with an acute ischemic stroke and to correlate the TSC with the extent of small vessel disease. Furthermore, the reliability of relative TSC (rTSC) compared to absolute TSC in these patients was analyzed. METHODOLOGY: We prospectively examined 62 patients with acute ischemic stroke (73 ± 13 years) between November 2016 and August 2019 from which 18 patients were excluded and thus 44 patients were evaluated. A 3D 23Na MRI was acquired in addition to a T2-TIRM and a diffusion-weighted image. Coregistration and segmentation were performed with SPM 12 based on the T2-TIRM image. The extension of WM T2 hyperintense lesions in each patient was classified using the Fazekas scale of WMLs. The absolute TSC in the WM region was correlated to the Fazekas grades. The stroke region was manually segmented on the coregistered absolute diffusion coefficient image and absolute, and rTSC was calculated in the stroke region and compared to nonischemic WM region. Statistical significance was evaluated using the Student t-test. RESULTS: For patients with Fazekas grade I (n = 25, age: 68.5 ± 15.1 years), mean TSC in WM was 55.57 ± 7.43 mM, and it was not statistically significant different from patients with Fazekas grade II (n = 7, age: 77.9 ± 6.4 years) with a mean TSC in WM of 53.9 ± 6.4 mM, p = 0.58. For patients with Fazekas grade III (n = 9, age: 81.4 ± 7.9 years), mean TSC in WM was 68.7 ± 10.5 mM, which is statistically significantly higher than the TSC in patients with Fazekas grade I and II (p < 0.001 and p = 0.05, respectively). There was a positive correlation between the TSC in WM and the Fazekas grade with r = 0.48 p < 0.001. The rTSC in the stroke region was statistically significant difference between low (0 and I) and high (2 and 3) Fazekas grades (p = 0.0353) whereas there was no statistically significant difference in absolute TSC in the stroke region between low (0 and I) and high (2 and 3) Fazekas grades. CONCLUSION: The significant difference in absolute TSC in WM in patients with severe small vessel disease; Fazekas grade 3 can lead to inaccuracies using rTSC quantification for evaluation of acute ischemic stroke using 23 Na MRI. The study, therefore, emphasizes the importance of absolute tissue sodium quantification.


Assuntos
Doenças de Pequenos Vasos Cerebrais/diagnóstico por imagem , AVC Isquêmico/diagnóstico por imagem , Leucoencefalopatias/diagnóstico por imagem , Imageamento por Ressonância Magnética , Isótopos de Sódio/metabolismo , Substância Branca/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Doenças de Pequenos Vasos Cerebrais/metabolismo , Imagem de Difusão por Ressonância Magnética , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , AVC Isquêmico/metabolismo , Leucoencefalopatias/metabolismo , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Reprodutibilidade dos Testes , Substância Branca/metabolismo
3.
NMR Biomed ; 34(4): e4474, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33480128

RESUMO

Quantitative 23 Na magnetic resonance imaging (MRI) provides tissue sodium concentration (TSC), which is connected to cell viability and vitality. Long acquisition times are one of the most challenging aspects for its clinical establishment. K-space undersampling is an approach for acquisition time reduction, but generates noise and artifacts. The use of convolutional neural networks (CNNs) is increasing in medical imaging and they are a useful tool for MRI postprocessing. The aim of this study is 23 Na MRI acquisition time reduction by k-space undersampling. CNNs were applied to reduce the resulting noise and artifacts. A retrospective analysis from a prospective study was conducted including image datasets from 46 patients (aged 72 ± 13 years; 25 women, 21 men) with ischemic stroke; the 23 Na MRI acquisition time was 10 min. The reconstructions were performed with full dataset (FI) and with a simulated dataset an image that was acquired in 2.5 min (RI). Eight different CNNs with either U-Net-based or ResNet-based architectures were implemented with RI as input and FI as label, using batch normalization and the number of filters as varying parameters. Training was performed with 9500 samples and testing included 400 samples. CNN outputs were evaluated based on signal-to-noise ratio (SNR) and structural similarity (SSIM). After quantification, TSC error was calculated. The image quality was subjectively rated by three neuroradiologists. Statistical significance was evaluated by Student's t-test. The average SNR was 21.72 ± 2.75 (FI) and 10.16 ± 0.96 (RI). U-Nets increased the SNR of RI to 43.99 and therefore performed better than ResNet. SSIM of RI to FI was improved by three CNNs to 0.91 ± 0.03. CNNs reduced TSC error by up to 15%. The subjective rating of CNN-generated images showed significantly better results than the subjective image rating of RI. The acquisition time of 23 Na MRI can be reduced by 75% due to postprocessing with a CNN on highly undersampled data.

4.
J Neuroimaging ; 31(2): 297-305, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33351997

RESUMO

BACKGROUND AND PURPOSE: To date, treatment response to stereotactic radiosurgery (SRS) in brain metastases (BM) can only be determined by MRI evaluation of contrast-enhancing lesions in a long-time follow-up. Sodium MRI has been a subject of immense interest in imaging research as the measure of tissue sodium concentration (TSC) can give valuable quantitative information on cell viability. We aimed to analyze the longitudinal changes of TSC in BM measured with 23 Na MRI before and after SRS for assessment of early local tumor effects. METHODS: Seven patients with a total of 12 previously untreated BM underwent SRS with 22 Gy. In addition to a standard MRI protocol including dynamic susceptibility-weighted contrast-enhanced perfusion, a 23 Na MRI was performed at three time points: (I) 2 days before, (II) 5 days, and (III) 40 days after SRS. Nine BMs were evaluated. The absolute TSC in the BM, the respective peritumoral edemas, and the normal-appearing corresponding contralateral brain area were assessed and the relative TSC were correlated to the changes in BM longest axial diameters. RESULTS: TSC was elevated in nine BM at baseline before SRS with a mean of 73.4 ± 12.3 mM. A further increase in TSC was observed 5 days after SRS in all the nine BM with a mean of 86.9 ± 13 mM. Eight of nine BM showed a mean 60.6 ± 13.3% decrease in the longest axial diameter 40 days after SRS; at this time point, the TSC also had decreased to a mean 65.1 ± 7.9 mM. In contrast, one of the nine BM had a 13.4% increase in the largest axial diameter at time point III. The TSC of this BM showed a further TSC increase of 80.1 mM 40 days after SRS. CONCLUSION: Changes in TSC using 23 Na MRI shows the possible capability to detect radiobiological changes in BM after SRS.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/metabolismo , Imageamento por Ressonância Magnética , Radiocirurgia , Sódio/metabolismo , Adulto , Idoso , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/radioterapia , Estudos de Viabilidade , Humanos , Masculino , Pessoa de Meia-Idade
5.
Orphanet J Rare Dis ; 15(1): 299, 2020 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-33097095

RESUMO

BACKGROUND: Revesz syndrome (RS) is an extremely rare variant of dyskeratosis congenita (DKC) with only anecdotal reports in the literature. METHODS: To further characterize the typical features and natural course of the disease, we screened the English literature and summarized the clinical and epidemiological features of previously published RS cases. In addition, we herein describe the first recorded patient in central Europe. RESULTS: The literature review included 18 children. Clinical features are summarized, indicating a low prevalence of the classical DKC triad. All patients experienced early bone marrow failure, in most cases within the second year of life (median age 1.5 years; 95% CI 1.4-1.6). Retinopathy occurred typically between 6 and 18 months of age (median age 1.1 years; 95% CI 0.7-1.5). The incidence of seizures was low and was present in an estimated 20% of patients. The onset of seizures was exclusively during early childhood. The Kaplan-Meier estimate of survival was dismal (median survival 6.5 years; 95% CI 3.6-9.4), and none of the patients survived beyond the age of 12 years. Stem cell transplantation (SCT) was performed in eight children, and after a median of 22 months from SCT four of these patients were alive at the last follow up visit. CONCLUSION: RS is a severe variant of DKC with early bone marrow failure and retinopathy in all patients. Survival is dismal, but stem cell transplantation may be performed successfully and might improve prognosis in the future.


Assuntos
Disceratose Congênita , Doenças Ósseas Metabólicas , Medula Óssea/anormalidades , Criança , Pré-Escolar , Disceratose Congênita/genética , Europa (Continente) , Humanos , Lactente , Retina
6.
Mult Scler Relat Disord ; 41: 102050, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32200343

RESUMO

We describe the case of a 6-year-old boy who developed myelin oligodendrocyte glycoprotein antibody (MOG-Ab) associated demyelinating syndrome, after initially presenting with aseptic meningitis. Magnetic resonance imaging showed cerebral and spinal lesions consistent with acute disseminating encephalomyelitis. Rapid clinical improvement occurred after intravenous high dose methylprednisolone. A small number of cases with MOG-Ab associated demyelinating syndrome presenting as aseptic meningitis have previously been reported in adults, but to our knowledge, this is the first pediatric case of this new clinical phenotype.


Assuntos
Encefalomielite Aguda Disseminada/diagnóstico , Encefalomielite Aguda Disseminada/imunologia , Meningite Asséptica/diagnóstico , Glicoproteína Mielina-Oligodendrócito/imunologia , Criança , Doenças Autoimunes Desmielinizantes do Sistema Nervoso Central , Humanos , Imageamento por Ressonância Magnética , Masculino
7.
In Vivo ; 33(6): 1967-1975, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31662526

RESUMO

BACKGROUND: Oral nimodipine is administered to improve clinical outcome in patients with aneurysmal subarachnoid hemorrhage (aSAH). In this study, clinical outcome in patients with and without oral nimodipine administration was assessed. MATERIALS AND METHODS: A total of 105 patients did not receive oral nimodipine but did receive intra-arterial nimodipine in the occurrence of hemodynamically relevant vasospasm after aSAH, whereas 74 patients received applications of both. Demographic/radiological details and clinical presentation were abstracted from the case records. RESULTS: Patient baseline characteristics were comparable, a predominance of endovascular coiling was shown in cohort 2 (p=0.0135). Severity of initial aSAH and clinical status at admission (Hunt and Hess) was significantly higher in those receiving oral nimodipine. Incidence of angiographic vasospasm was significantly higher in patients not treated with oral nimodipine (p=0.0305); a significantly better outcome measured by the National Institute of Health Stroke Scale (p=0.0213), was noted in those receiving oral nimodipine. CONCLUSION: Oral nimodipine administration improved clinical outcome of patients after aSAH and should be administered routinely for such patients.


Assuntos
Aneurisma Intracraniano/tratamento farmacológico , Nimodipina/administração & dosagem , Hemorragia Subaracnóidea/tratamento farmacológico , Vasodilatadores/administração & dosagem , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Incidência , Infusões Intra-Arteriais/métodos , Injeções Intra-Arteriais/métodos , Masculino , Pessoa de Meia-Idade , Acidente Vascular Cerebral/tratamento farmacológico , Resultado do Tratamento
8.
Invest Radiol ; 53(9): 555-562, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29863602

RESUMO

OBJECTIVES: Sodium magnetic resonance (MR) imaging provides noninvasive insights to cellular processes by measuring tissue sodium concentration (TSC). Many clinical studies combine sodium MR imaging with clinical standard MR procedures, in which contrast media is frequently administered. This work investigates the influence of gadolinium-based contrast agents on quantification of TSC. Thus, either scan pauses between early and late contrast-enhanced acquisitions can be used efficiently or sodium imaging can be performed as the final scan after dynamic contrast-enhanced acquisition. MATERIALS AND METHODS: For this study, 2 gadolinium-based contrast agents, Dotarem and Gadovist, were diluted with saline solution covering contrast agent concentrations in a clinical range. In addition, agarose-based sample series were created to simulate tissue relaxation time behavior. In vivo, the influence of Dotarem on sodium acquisition and TSC quantification was investigated in 1 ischemic stroke patient. RESULTS: Proton relaxation times decreased for increasing contrast agent concentrations as hyperbolic functions. Sodium relaxation times displayed a negative slope in regression analysis in most cases. The largest influence (-1.52 milliseconds per mmol/L contrast agent) was measured for sodium T1. Worst case calculations in ultrashort echo time sequence signal analysis showed a signal drop of (1.21% ± 0.56%) on tissue sodium quantification. In vivo sodium brain acquisitions of a stroke patient before and after Dotarem injection resulted in statistically nonsignificant differences in TSC quantification of relevant tissues and stroke areas (P > 0.05). CONCLUSIONS: Our study showed a quantitative influence of Dotarem and Gadovist on sodium relaxation times. However, quantification of TSC was not impaired, which was proven by worst case calculations and nonsignificant differences in vivo in an ischemic stroke patient. We suggest performing sodium imaging in useful clinical positions in protocols regardless of included Dotarem or Gadovist administrations. Being flexible in the study protocol design will strengthen ongoing sodium imaging investigations for various pathologies.


Assuntos
Encéfalo/metabolismo , Meios de Contraste/farmacologia , Imageamento por Ressonância Magnética/métodos , Meglumina/farmacologia , Compostos Organometálicos/farmacologia , Sódio/metabolismo , Feminino , Humanos , Pessoa de Meia-Idade , Imagens de Fantasmas
9.
J Stroke Cerebrovasc Dis ; 27(5): 1343-1349, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29395641

RESUMO

BACKGROUND: Intravenous thrombolysis with recombinant tissue plasminogen activator is still not approved by the European Medicines Agency for patients with diabetes mellitus and previous stroke. We assessed functional benefit and potential risk of thrombolysis in patients with diabetes and previous stroke and the influence of age, preexisting diabetic damage, as well as acute and chronic hyperglycemia on outcome, symptomatic intracranial hemorrhage, and in-hospital mortality. METHODS: We analyzed 527 consecutive patients treated with thrombolysis for acute stroke. Poor outcome was defined as deterioration of prestroke modified Rankin Scale (mRS) to 3 or greater at discharge. Symptomatic intracranial hemorrhage was defined according to the Safe Implementation of Thrombolysis in Stroke-Monitoring Study criteria. RESULTS: Of the patients, 35.9% were diabetic and 33.2% had previous stroke. Of these patients, 14.4% were diabetics with previous stroke (index group). The rate of patients with poor functional outcome at discharge, symptomatic intracranial hemorrhage, or mortality did not differ between the index group and patients with either diabetes or previous stroke in 2 × 2 comparisons. Diabetics with first-ever stroke showed significantly more symptomatic intracranial hemorrhage (9.7%, P < .001) than the other groups, poorer functional recovery (P = .036), and the highest rate of mortality (12.4%, P < .001). Significant predictors for poor outcome were age (P < .001) and HbA1c (P = .013), for symptomatic intracranial hemorrhage HbA1c (P = .006) and for mortality acute hyperglycemia (P = .001) and age (P = .004). CONCLUSION: Diabetics with previous stroke should not be withheld from intravenous thrombolysis. The risk of complications derives primarily from poor long-term metabolic control rather than from acute hyperglycemia or from previous stroke.


Assuntos
Diabetes Mellitus/epidemiologia , Fibrinolíticos/administração & dosagem , Acidente Vascular Cerebral/tratamento farmacológico , Terapia Trombolítica , Ativador de Plasminogênio Tecidual/administração & dosagem , Administração Intravenosa , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Glicemia/metabolismo , Bases de Dados Factuais , Diabetes Mellitus/sangue , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/mortalidade , Avaliação da Deficiência , Feminino , Fibrinolíticos/efeitos adversos , Alemanha/epidemiologia , Hemoglobina A Glicada/metabolismo , Humanos , Hemorragias Intracranianas/induzido quimicamente , Masculino , Pessoa de Meia-Idade , Recuperação de Função Fisiológica , Recidiva , Estudos Retrospectivos , Fatores de Risco , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/mortalidade , Acidente Vascular Cerebral/fisiopatologia , Terapia Trombolítica/efeitos adversos , Terapia Trombolítica/mortalidade , Fatores de Tempo , Ativador de Plasminogênio Tecidual/efeitos adversos , Resultado do Tratamento
10.
J Thromb Thrombolysis ; 45(4): 529-535, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29476304

RESUMO

BACKGROUND: Non-vitamin K antagonist oral anticoagulants (NOACs) have gained increasing importance for stroke prevention in patients with non-valvular atrial fibrillation (AF). With changing prescription practice, among other factors, clinicians can expect to see rising numbers of patients with ischemic stroke and pre-existing NOAC therapy. Few data exist regarding a potential impact of NOAC on stroke severity and outcome. AIMS: To evaluate the impact of pre-admission NOAC therapy on ischemic stroke severity. METHODS: Retrospective analysis of medical data of 376 patients with newly detected AF or known AF with either no pre-admission oral anticoagulation (n = 277) or existing NOAC therapy (n = 99; Apixaban, n = 33, Dabigatran, n = 16; Edoxaban, n = 1; Rivaroxaban, n = 49) consecutively admitted for acute ischemic stroke between January 2015 and December 2016. RESULTS: Patients with pre-admission NOAC had significantly more often experienced a prior stroke than patients not on NOAC therapy (45.5 vs. 18.4%, p < 0.001) and were significantly more frequently non-smokers (1.0 vs. 7.2%, p = 0.021). Significantly more patients without pre-admission NOAC received thrombolysis (33.8 vs. 8.1%, p < 0.001). Pre-admission NOAC therapy was associated with significantly lower NIHSS and mRS scores upon admission (median NIHSS score 6 vs. 10, p = 0.018, median mRS score 4 vs. 5, p = 0.035) and trend-level lower NIHSS scores at discharge (median NIHSS score 3 vs. 5, p = 0.057). There were no differences regarding the frequency of symptomatic intracerebral hemorrhage between NOAC and non-NOAC patients (p > 0.05). CONCLUSIONS: We report a positive impact of pre-admission NOAC on ischemic stroke severity, which is particularly remarkable in light of the increased prevalence of prior stroke and lower rates of thrombolysis in this patient population.


Assuntos
Anticoagulantes/uso terapêutico , Isquemia Encefálica , Acidente Vascular Cerebral/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Fibrilação Atrial/complicações , Hemorragia Cerebral/induzido quimicamente , Humanos , Pessoa de Meia-Idade , Admissão do Paciente , Recidiva , Estudos Retrospectivos , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/patologia , Terapia Trombolítica
11.
Ther Adv Neurol Disord ; 11: 1756285617753423, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29449886

RESUMO

Background: The safety of systemic thrombolysis in patients with intracranial tumor and cavernoma are unknown. So far evidence is limited to a number of case reports and few case series or unspecified data based on population-based analysis. Our aim was to comprehend the risk of systemic thrombolysis in these patients. Methods: Patients with additional evidence of intracranial tumor or cavernoma who received IV tissue plasminogen activator (t-PA) treatment at our comprehensive stroke center over a period of 7 years were identified in our stroke database and compared to the same number of matched control subjects without any evidence of intracranial tumor and cavernoma. Clinical history and imaging patterns before and after t-PA therapy were individually reviewed for each patient. Results: Thirty-four patients with additional evidence of meningioma (19/34), cavernoma (13/34) or malignant intracranial neoplasm (2/34) were identified. The incidence of secondary intracranial hemorrhage observed showed no difference between control subjects (9/34, 26%) and patients (6/34, 18%; p = 0.56). Symptomatic hemorrhage in patients with meningioma or cavernoma could not be observed. Likewise, the prevalence of stroke mimics showed no difference between patients (8/34, 24%) and control subjects (5/34, 15%; p = 0.54). However, both patients with malignant intracranial neoplasm presented with a stroke mimic and intracranial hemorrhage was observed in one of them. Conclusions: In compliance with existing evidence, treatment in patients with meningioma and cavernoma appears to be safe and reasonable, while the therapy should be avoided in patients with malignant intracranial neoplasm with blood-brain barrier disruption.

12.
Clin Neuroradiol ; 28(2): 225-234, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29313057

RESUMO

BACKGROUND AND PURPOSE: Mechanical thrombectomy, in addition to intravenous (i.v.) thrombolysis is recommended for treatment of acute stroke in patients with large vessel occlusions (LVO) in the anterior circulation up to 6 h after symptom onset. We compared thrombectomy rates of eight university hospitals of the MIRACUM consortium to analyze the implementation of this guideline in clinical routine. METHODS: Anonymized billing data in a standardized format were loaded into a local i2b2 data warehouse by applying already existing extract, transform and load (ETL) routines. A locally executed uniform SQL (structured query language) query delivered aggregated site data for all inpatients with a discharge diagnosis of ischemic stroke (ICD-10 I63) containing counts for type of acute treatment, type of admission and age groups, which were centrally analyzed with R. RESULTS: From 2014 to 2016, the thrombectomy rate almost doubled from a mean of 4.7% to 9.6%, although significant differences between centers exist (range in 2016: 5.8-17%). The number of drip-and-ship procedures increased in 3 out of 8 centers. There was no evidence for a decrease in thrombectomy rates during weekends/holiday or among patients older than 80 years, but this age group is more likely to receive i.v. recombinant tissue plasminogen activator (rtPA). CONCLUSION: The observed increase of thrombectomy rates and drip-and-ship procedures without a significant difference between weekdays and weekends or patients of different ages is substantiating a rapid implementation of stroke guidelines within the analyzed neurovascular centers. The prototype of the MIRACUM Data Integration Center already contributes to health services research in Germany.


Assuntos
Padrões de Prática Médica/estatística & dados numéricos , Trombectomia/estatística & dados numéricos , Terapia Trombolítica/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Isquemia Encefálica , Feminino , Fibrinolíticos , Alemanha , Humanos , Masculino , Informática Médica , Pessoa de Meia-Idade , Acidente Vascular Cerebral , Ativador de Plasminogênio Tecidual , Resultado do Tratamento
13.
Int J Stroke ; 10 Suppl A100: 56-61, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26121064

RESUMO

BACKGROUND: Established imaging methods are still not confident in the determination of stroke onset. Sodium imaging in animal models and lately in humans implicates that the sodium signal intensity within the ischemic lesion increases in a time-dependent fashion. Sodium imaging usually requires a time-consuming change of resonators or magnetic resonance imaging systems. To avoid this, we used a double-tuned (1) H/(23) Na birdcage head coil in combination with a protocol minimizing T1 - and T2 *-weighting effects for measurement of sodium intensity in acute stroke patients. METHODS: Multinuclear (1) H/(23) Na data sets were obtained from 16 stroke patients [75 ± 9·9 (standard deviation) years old] 4-130 h after symptom onset. The protocol was acquired on a clinical 3T magnetic resonance imaging site using a double-tuned (1) H/(23) Na birdcage head coil. Sodium signal intensity within the lesion and homologous contralateral side was measured and compared. RESULTS: With an acquisition time of the complete magnetic resonance imaging protocol of 22 min, a nonlinear sodium signal intensity increase within the lesion over time after stroke onset was acknowledged. Onset time within six-hours showed an increase of only 8% or less, whereas onset time beyond 8·5 h demonstrated increases of 36% or more reaching a maximum of 170% > 120 h. In addition, some patients showed a difference in sodium signal intensity compared with diffusion weighted imaging lesion. CONCLUSIONS: The use of a double-tuned (1) H/(23) Na birdcage head coil in a clinical setting 'allowed sodium intensity measurements' in a justifiable time also for acute stroke patients, and heterogenous sodium signal intensity in the diffusion weighted imaging lesion might represent differences in tissue damage or repair.


Assuntos
Isquemia Encefálica/complicações , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/etiologia , Idoso , Idoso de 80 Anos ou mais , Mapeamento Encefálico , Imagem de Difusão por Ressonância Magnética , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Cintilografia , Radioisótopos de Sódio/metabolismo , Acidente Vascular Cerebral/diagnóstico por imagem , Trítio/metabolismo
14.
Z Med Phys ; 25(3): 275-86, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25270979

RESUMO

AIM: To evaluate potential scan time reduction in (23)Na-Magnetic Resonance Imaging with the chemical shift imaging sequence (CSI) using undersampled data of high-quality datasets, reconstructed with an iterative constrained reconstruction, compared to reduced resolution or reduced signal-to-noise ratio. MATERIALS AND METHODS: CSI (23)Na-images were retrospectively undersampled and reconstructed with a constrained reconstruction scheme. The results were compared to conventional methods of scan time reduction. The constrained reconstruction scheme used a phase constraint and a finite object support, which was extracted from a spatially registered (1)H-image acquired with a double-tuned coil. The methods were evaluated using numerical simulations, phantom images and in-vivo images of a healthy volunteer and a patient who suffered from cerebral ischemic stroke. RESULTS: The constrained reconstruction scheme showed improved image quality compared to a decreased number of averages, images with decreased resolution or circular undersampling with weighted averaging for any undersampling factor. Brain images of a stroke patient, which were reconstructed from three-fold undersampled k-space data, resulted in only minor differences from the original image (normalized root means square error < 12%) and an almost identical delineation of the stroke region (mismatch < 6%). CONCLUSION: The acquisition of undersampled (23)Na-CSI images enables up to three-fold scan time reduction with improved image quality compared to conventional methods of scan time saving.


Assuntos
Encéfalo/metabolismo , Encéfalo/patologia , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Sódio/farmacocinética , Algoritmos , Estudos de Viabilidade , Humanos , Imagem Molecular/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Fatores de Tempo
15.
Neuroradiology ; 55(1): 71-6, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22864556

RESUMO

INTRODUCTION: Cerebral vasospasm is a severe complication of subarachnoid hemorrhage (SAH). The calcium channel inhibitor nimodipine has been used for treatment of cerebral vasospasm. No evidence-based recommendations for local nimodipine administration at the site of vasospasm exist. The purpose of this study was to quantify nimodipine's local vasodilatory effect in an ex vivo model of SAH-induced vasospasm. METHODS: SAH-induced vasospasm was modeled by contracting isolated segments of rat superior cerebellar arteries with a combination of serotonin and a synthetic analog of prostaglandin A(2). A pressure myograph system was used to determine vessel reactivity of spastic as well as non-spastic arteries. RESULTS: Compared to the initial vessel diameter, a combination of serotonin and prostaglandin induced considerable vasospasm (55 ± 2.5 % contraction; n = 12; p < 0.001). Locally applied nimodipine dilated the arteries in a concentration-dependent manner starting at concentrations as low as 1 nM (n = 12; p < 0.05). Concentrations higher than 100 nM did not relevantly increase the vasodilatory effect. Nimodipine's vasodilatory effect was smaller in spastic than in non-spastic vessels (n = 12; p < 0.05), which we assume to be due to structural changes in the vessel wall. CONCLUSION: The described ex vivo model allows to investigate the dose-dependent efficacy of spasmolytic drugs prior to in vivo experiments. Low concentrations of locally applied nimodipine have a strong vasodilatory effect, which is of relevance when considering the local application of nimodipine in cerebral vasospasm.


Assuntos
Artérias Cerebrais/efeitos dos fármacos , Artérias Cerebrais/fisiopatologia , Nimodipina/administração & dosagem , Vasoespasmo Intracraniano/tratamento farmacológico , Vasoespasmo Intracraniano/fisiopatologia , Animais , Relação Dose-Resposta a Droga , Masculino , Ratos , Ratos Wistar , Resultado do Tratamento , Resistência Vascular/efeitos dos fármacos , Vasodilatadores/administração & dosagem
16.
GMS Z Med Ausbild ; 29(2): Doc16, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22558022

RESUMO

The compatibility of studies or a career with children is becoming increasingly important. This is partly attributable to the fact that it is important for people of either gender to spend time with their families, their children. Not too long ago, raising children was almost exclusively the domain of the mother. On the other hand, more and more women study medicine. More than half of first year students are now female. Many of these young women, like their male counterparts, would like to start families. The possibility to both study and have children is particularly important during the "training" life phase. The Medical Faculty Mannheim realises the need for action and wants to actively tackle the associated challenges in terms of advice, study design and infrastructure. This article represents the steps which the faculty - in close cooperation with the Equality Office, the Dean of Studies and the University Hospital - has taken so far or is currently putting in place to enable students to successfully combine the challenge of studying with that of having children. These include individual advice services on study organisation, information about support services, changes to the infrastructure and more intensive cooperation between the various departments.


Assuntos
Educação Infantil , Educação Médica , Docentes de Medicina , Médicas/psicologia , Apoio Social , Estudantes de Medicina/psicologia , Adulto , Criança , Currículo , Coleta de Dados , Feminino , Alemanha , Humanos , Renda , Internato e Residência , Masculino , Poder Familiar/psicologia , Médicas/estatística & dados numéricos , Gravidez , Responsabilidade Social , Estudantes de Medicina/estatística & dados numéricos , Tolerância ao Trabalho Programado
17.
Cerebrovasc Dis ; 31(4): 353-7, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21212667

RESUMO

BACKGROUND: To assess the efficiency of IIb/IIIa platelet receptor inhibition by abciximab in the prevention of silent embolism during digital subtraction angiography. METHODS: In this randomized, double-blind, prospective study, pre- and postangiographic diffusion-weighted magnetic resonance imaging (DWI) of 184 participants was evaluated for the occurrence of silent embolism. RESULTS: No significant relationship was found between the patients receiving abciximab before digital subtraction angiography (15 of 90; 16.7%) and patients in the placebo group (16 of 94; 17.0%) regarding postangiographic appearance of silent emboli (p = 0.9). CONCLUSIONS: IIb/IIIa receptor inhibition by abciximab does not diminish the occurrence of silent embolism during digital subtraction angiography. Our findings indicate that solid blood clots are not the origin of hyperintense lesions observed on DWI and enhance the role of alternative mechanisms.


Assuntos
Angiografia Digital/efeitos adversos , Anticorpos Monoclonais/uso terapêutico , Isquemia Encefálica/prevenção & controle , Angiografia Cerebral/efeitos adversos , Fragmentos Fab das Imunoglobulinas/uso terapêutico , Embolia Intracraniana/prevenção & controle , Inibidores da Agregação Plaquetária/uso terapêutico , Abciximab , Isquemia Encefálica/sangue , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/etiologia , Imagem de Difusão por Ressonância Magnética , Método Duplo-Cego , Feminino , Alemanha , Humanos , Embolia Intracraniana/sangue , Embolia Intracraniana/diagnóstico , Embolia Intracraniana/etiologia , Masculino , Pessoa de Meia-Idade , Efeito Placebo , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/antagonistas & inibidores , Estudos Prospectivos , Fatores de Risco , Falha de Tratamento
18.
Anticancer Res ; 29(8): 3261-7, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19661344

RESUMO

BACKGROUND: Gliomatosis cerebri is a rare primary cerebral tumour entity characterized by diffuse infiltrative growth patterns representing a WHO grade III malignancy. The prognosis is dismal and therapeutical options are still controversial. In contrast to other high-grade gliomas, angiogenesis is thought to be absent in gliomatosis cerebri. PATIENTS AND METHODS: Despite this assumption, histopathological analyses of samples of six patients with gliomatosis cerebri were performed and surprisingly there was angiogenic activity with expression of vascular endothelial growth factor and cyclooxygenase 2. It was therefore decided to administer continuous low-dose chemotherapy with temozolomide and celecoxib for antiangiogenic treatment in the four patients that were in good clinical condition following external radiotherapy. RESULTS: In all patients, treatment was well tolerated and MRI follow-up showed no tumour progression for at least six months. One patient died due to pulmonary embolism 9 months after diagnosis; another patient survived 15 months after diagnosis with progressive disease in the last follow-up MRI before death. Two other patients at the present time are still in a stable clinical condition without signs of tumour progression in MRI (12 and 18 months). CONCLUSION: From our initial experience in a small number of patients with gliomatosis cerebri with signs of angiogenic activity, we conclude that low-dose chemotherapy might provide a promising approach for treatment of these patients and that overexpression of angiogenic factors such as VEGF or COX-2 seems to be more frequent than hitherto reported.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Neuroepiteliomatosas/irrigação sanguínea , Neoplasias Neuroepiteliomatosas/tratamento farmacológico , Neovascularização Patológica/prevenção & controle , Adulto , Idoso , Celecoxib , Proliferação de Células , Ciclo-Oxigenase 2/metabolismo , Dacarbazina/administração & dosagem , Dacarbazina/análogos & derivados , Progressão da Doença , Relação Dose-Resposta a Droga , Feminino , Humanos , Técnicas Imunoenzimáticas , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Neuroepiteliomatosas/patologia , Prognóstico , Pirazóis/administração & dosagem , Sulfonamidas/administração & dosagem , Taxa de Sobrevida , Temozolomida , Fator A de Crescimento do Endotélio Vascular/metabolismo
19.
Klin Neuroradiol ; 19(1): 91-100, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19636682

RESUMO

Spontaneous dural arteriovenous fistulas (DAVFs) are abnormal arteriovenous shunts within the dura mater of the sinuses. The exact etiology remains uncertain. Arterial feeder derive from the meningeal branches in the region. The clinical symptoms are highly dependent on the venous drainage. Computed tomography (CT) and magnetic resonance imaging (MRI) demonstrate the epiphenomena rather than the DAVF itself. Angiography is the most important modality in evaluating a DAVF. Based on the patterns of venous drainage, a classification and a treatment strategy are possible. Therapeutic modalities include manual compression, transarterial embolization, transvenous embolization, and/or surgical resection. Recent technical advances concerning embolic material and microcatheter make endovascular treatment less dangerous and more effective.


Assuntos
Angiografia Cerebral/métodos , Revascularização Cerebral/métodos , Embolização Terapêutica/métodos , Malformações Arteriovenosas Intracranianas/diagnóstico , Malformações Arteriovenosas Intracranianas/terapia , Humanos
20.
Brain ; 132(Pt 7): 1764-82, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19433437

RESUMO

In glutaric aciduria type I, an autosomal recessive disease of mitochondrial lysine, hydroxylysine and tryptophan catabolism, striatal lesions are characteristically induced by acute encephalopathic crises during a finite period of brain development (age 3-36 months). The frequency of striatal injury is significantly less in patients diagnosed as asymptomatic newborns by newborn screening. Most previous studies have focused on the onset and mechanism of striatal injury, whereas little is known about neuroradiological abnormalities in pre-symptomatically diagnosed patients and about dynamic changes of extrastriatal abnormalities. Thus, the major aim of the present retrospective study was to improve our understanding of striatal and extrastriatal abnormalities in affected individuals including those diagnosed by newborn screening. To this end, we systematically analysed magnetic resonance imagings (MRIs) in 38 patients with glutaric aciduria type I diagnosed before or after the manifestation of neurological symptoms. To identify brain regions that are susceptible to cerebral injury during acute encephalopathic crises, we compared the frequency of magnetic resonance abnormalities in patients with and without such crises. Major specific changes after encephalopathic crises were found in the putamen (P < 0.001), nucleus caudatus (P < 0.001), globus pallidus (P = 0.012) and ventricles (P = 0.001). Analysis of empirical cumulative distribution frequencies, however, demonstrated that isolated pallidal abnormalities did not significantly differ over time in both groups (P = 0.544) suggesting that isolated pallidal abnormalities are not induced by acute crises--in contrast to striatal abnormalities. The manifestation of motor disability was associated with signal abnormalities in putamen, caudate, pallidum and ventricles. In addition, we found a large number of extrastriatal abnormalities in patients with and without preceding encephalophatic crises. These abnormalities include widening of anterior temporal and sylvian CSF spaces, pseudocysts, signal changes of substantia nigra, nucleus dentatus, thalamus, tractus tegmentalis centralis and supratentorial white matter as well as signs of delayed maturation (myelination and gyral pattern). In contrast to the striatum, extrastriatal abnormalities were variable and could regress or even normalize with time. This includes widening of sylvian fissures, delayed maturation, pallidal signal changes and pseudocysts. Based on these results, we hypothesize that neuroradiological abnormalities and neurological symptoms in glutaric aciduria type I can be explained by overlaying episodes of cerebral alterations including maturational delay of the brain in utero, acute striatal injury during a vulnerable period in infancy and chronic progressive changes that may continue lifelong. This may have widespread consequences for the pathophysiological understanding of this disease, long-term outcomes and therapeutic considerations.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/patologia , Encefalopatias Metabólicas Congênitas/patologia , Encéfalo/patologia , Glutaril-CoA Desidrogenase/deficiência , Doença Aguda , Adolescente , Adulto , Fatores Etários , Idoso , Erros Inatos do Metabolismo dos Aminoácidos/diagnóstico , Erros Inatos do Metabolismo dos Aminoácidos/metabolismo , Atrofia , Gânglios da Base/patologia , Encefalopatias Metabólicas Congênitas/diagnóstico , Encefalopatias Metabólicas Congênitas/metabolismo , Mapeamento Encefálico/métodos , Cerebelo/patologia , Criança , Desenvolvimento Infantil , Pré-Escolar , Corpo Estriado/patologia , Progressão da Doença , Seguimentos , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual/patologia , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Transtornos dos Movimentos/etiologia , Transtornos dos Movimentos/patologia , Estudos Retrospectivos , Adulto Jovem
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