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1.
Dalton Trans ; 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39007227

RESUMO

Understanding structure-property relationship in redox-active molecular species is of central importance in various fields, including many medicinal and chemical applications. The quest for performant organic electrodes in the context of energy storage calls for pioneering studies to develop new and possibly optimal materials. Beyond modifying the molecular design of the existing compounds through functionalization, expansion of the search enabling the advent of efficient new backbones can potentially lead to breakthroughs in this research area. The number of already identified families able to constitute negative organic electrodes is much lower than that of their positive counterparts, which calls for finding ways to bridge this gap. To expand the dataset of known predicted redox potentials and in view of reaching an educated guess about the abilities of some eventual new redox active electrodes, we examined the properties of pyrazine N,N'-dioxide (PZDO) and its fully methylated functionalized derivative (TeMePzDO). The aspects and mechanisms driving the various features characteristic of these compounds were unraveled through molecular and periodic DFT calculations combined with accurate electronic structure analysis. The predicted molecular redox/crystalline intercalation potentials lead to the classification of PZDO and TeMePzDO systems within the class of negative electrodes, with features that are significantly appealing compared to those of some existing systems with backbones suited for such kind of application.

2.
Int J Stroke ; : 1747493019833017, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30873912

RESUMO

BACKGROUND: Treatment of individuals with asymptomatic carotid artery stenosis is still handled controversially. Recommendations for treatment of asymptomatic carotid stenosis with carotid endarterectomy (CEA) are based on trials having recruited patients more than 15 years ago. Registry data indicate that advances in best medical treatment (BMT) may lead to a markedly decreasing risk of stroke in asymptomatic carotid stenosis. The aim of the SPACE-2 trial (ISRCTN78592017) was to compare the stroke preventive effects of BMT alone with that of BMT in combination with CEA or carotid artery stenting (CAS), respectively, in patients with asymptomatic carotid artery stenosis of ≥70% European Carotid Surgery Trial (ECST) criteria. METHODS: SPACE-2 is a randomized, controlled, multicenter, open study. A major secondary endpoint was the cumulative rate of any stroke (ischemic or hemorrhagic) or death from any cause within 30 days plus an ipsilateral ischemic stroke within one year of follow-up. Safety was assessed as the rate of any stroke and death from any cause within 30 days after CEA or CAS. Protocol changes had to be implemented. The results on the one-year period after treatment are reported. FINDINGS: It was planned to enroll 3550 patients. Due to low recruitment, the enrollment of patients was stopped prematurely after randomization of 513 patients in 36 centers to CEA (n = 203), CAS (n = 197), or BMT (n = 113). The one-year rate of the major secondary endpoint did not significantly differ between groups (CEA 2.5%, CAS 3.0%, BMT 0.9%; p = 0.530) as well as rates of any stroke (CEA 3.9%, CAS 4.1%, BMT 0.9%; p = 0.256) and all-cause mortality (CEA 2.5%, CAS 1.0%, BMT 3.5%; p = 0.304). About half of all strokes occurred in the peri-interventional period. Higher albeit statistically non-significant rates of restenosis occurred in the stenting group (CEA 2.0% vs. CAS 5.6%; p = 0.068) without evidence of increased stroke rates. INTERPRETATION: The low sample size of this prematurely stopped trial of 513 patients implies that its power is not sufficient to show that CEA or CAS is superior to a modern medical therapy (BMT) in the primary prevention of ischemic stroke in patients with an asymptomatic carotid stenosis up to one year after treatment. Also, no evidence for differences in safety between CAS and CEA during the first year after treatment could be derived. Follow-up will be performed up to five years. Data may be used for pooled analysis with ongoing trials.

3.
Eur J Neurol ; 25(11): 1326-1332, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29924461

RESUMO

BACKGROUND AND PURPOSE: External counterpulsation improves cerebral perfusion velocity in acute stroke and may stimulate collateral artery growth. However, whether (non-acute) at-risk patients with high-grade carotid artery disease may benefit from counterpulsation needs to be validated. METHODS: Twenty-eight patients (71 ± 6.5 years, five women) with asymptomatic unilateral chronic severe internal carotid artery stenosis (>70%) or occlusion were randomized to receive 20 min active counterpulsation followed by sham treatment or vice versa. Cerebral blood flow velocity (CBFV) (measured bilaterally by transcranial middle cerebral artery Doppler), tissue oxygenation index (TOI) (measured over the bilateral prefrontal cortex by near-infrared spectroscopy) and cerebral hemodynamic parameters, such as relative pulse slope index (RPSI), were monitored. RESULTS: Ipsilateral mean CBFV (ΔVmean +3.5 ± 1.2 cm/s) and tissue oxygenation (ΔTOI +2.86 ± 0.8) increased significantly during active counterpulsation compared to baseline, whilst the sham had little effect (ΔVmean +1.13 ± 1.1 cm/s; ΔTOI +1.25 ± 0.65). On contralateral sides, neither counterpulsation nor sham control had any effect on either parameter. During counterpulsation, early dynamic changes in ΔRPSI of the ipsilateral CBFV signal predicted improved tissue oxygenation during counterpulsation (odds ratio 1.179, 95% confidence interval 1.01-1.51), whilst baseline cerebrovascular reactivity to hypercapnia failed to show an association. CONCLUSIONS: In patients with high-grade carotid disease, ipsilateral cerebral oxygenation and blood flow velocity are increased by counterpulsation. This is a necessary condition for the stimulation of regenerative collateral artery growth and thus a therapeutic concept for the prevention of cerebral ischaemia. This study provides a rationale for further clinical investigations on the long-term effects of counterpulsation on cerebral hemodynamics and collateral growth.


Assuntos
Circulação Cerebrovascular/fisiologia , Transtornos Cerebrovasculares/terapia , Contrapulsação , Idoso , Velocidade do Fluxo Sanguíneo/fisiologia , Transtornos Cerebrovasculares/diagnóstico por imagem , Transtornos Cerebrovasculares/fisiopatologia , Feminino , Hemodinâmica/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/diagnóstico por imagem , Ultrassonografia Doppler Transcraniana
5.
Neuroscience ; 206: 7-16, 2012 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-22280974

RESUMO

The basolateral amygdala (BLA) plays an important role in the formation of associations between context and drug. BLA activity and BLA-dependent drug-seeking behavior are driven by excitatory inputs. Drug-seeking behavior driven by context involves participation of the BLA, and plasticity of excitatory inputs to the BLA may contribute to this behavior. In this study, amphetamine conditioned place preference (AMPH CPP) was used to model the formation of context-drug associations. Learning-induced changes of excitatory synapses within the BLA were examined. Male Sprague-Dawley rats were assigned to one of three groups, the experimental group (AMPH CPP) or one of two control groups (saline or AMPH delayed pairing). Approximately 24 h after testing their preference, spontaneous and miniature excitatory postsynaptic currents (sEPSCs and mEPSCs, respectively) in BLA pyramidal neurons were investigated using whole-cell patch-clamp recordings. There were no between-groups differences in the amplitude or frequency of sEPSCs or mEPSCs. In a higher osmolarity solution to increase release, there was a significantly greater frequency of the mEPSCs in neurons from AMPH CPP animals compared with controls. This was observed with no change detected in the probability of glutamate release. Together, these data demonstrate no evidence for increased synaptic strength, but are consistent with an increase in the number of synapses in the BLA after AMPH CPP. These findings may underlie increased excitatory drive of the BLA after AMPH CPP, and contribute to the animals' preference for the AMPH-paired compartment.


Assuntos
Anfetamina/farmacologia , Tonsila do Cerebelo/efeitos dos fármacos , Estimulantes do Sistema Nervoso Central/farmacologia , Condicionamento Psicológico/efeitos dos fármacos , Sinapses/efeitos dos fármacos , Tonsila do Cerebelo/fisiologia , Animais , Comportamento de Procura de Droga/fisiologia , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Aprendizagem/efeitos dos fármacos , Aprendizagem/fisiologia , Masculino , Técnicas de Patch-Clamp , Ratos , Ratos Sprague-Dawley , Sinapses/fisiologia
6.
Acta Neurol Scand ; 125(3): 156-62, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21470192

RESUMO

OBJECTIVES: Cerebral autoregulation is particularly challenged in acute ischemic stroke. We investigated (1) clinical and radiological factors related to dynamic cerebral autoregulation (DCA) in acute stroke and (2) the relationship between DCA and clinical outcome of stroke. METHODS: A total of 45 patients with middle cerebral artery (MCA) stroke were analyzed pooling two previous studies. DCA was measured by transcranial Doppler in both MCAs early (within 48 h from onset) and late (day 5-7) using low-frequency phase and correlation analysis (index Mx). Outcome was assessed by modified Rankin scale after a mean period of 4 months. RESULTS: Mx increased (i.e. autoregulation worsened) between the early and late measurement, more so on affected (P = 0.005) than on unaffected sides (P = 0.014). Poorer autoregulation as indicated by lower ipsilateral phase (early and late) and higher Mx (late measurement) were significantly related to larger infarction. More severe stroke was significantly related to poorer ipsilateral Mx and phase. Ipsilateral phase in the early (P = 0.019) and Mx in the late measurement (P =0..016) were related to poor clinical outcome according to univariate analysis. CONCLUSIONS: Impairment of DCA ipsilateral to acute ischemic stroke is associated with larger infarction. Dysautoregulation tends to worsen and spread to the contralateral side over the first days post-stroke and is associated with poor clinical outcome.


Assuntos
Infarto Encefálico/patologia , Infarto Encefálico/fisiopatologia , Isquemia Encefálica/patologia , Isquemia Encefálica/fisiopatologia , Circulação Cerebrovascular/fisiologia , Homeostase/fisiologia , Idoso , Infarto Encefálico/diagnóstico por imagem , Isquemia Encefálica/diagnóstico por imagem , Feminino , Humanos , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Infarto da Artéria Cerebral Média/patologia , Infarto da Artéria Cerebral Média/fisiopatologia , Masculino , Pessoa de Meia-Idade , Ultrassonografia
7.
Z Rheumatol ; 68(2): 108-16, 2009 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-19153753

RESUMO

This article summarizes the examination technique, typical findings, interpretation and limitations of ultrasound diagnosis in patients with giant cell arteritis. Colour-coded sonography of the temporal artery has gained increasing attention. If experienced ultrasound examiners are available, diagnosis of giant cell arteritis in patients with a typical clinical constellation can be made based solely on sonographic findings, in particular by a hypoechogenic halo. The hitherto probably under-diagnosed large vessel variant of giant cell arteritis shows characteristic findings with a simple and quick ultrasound examination of the proximal arm arteries. High resolution MRI has been shown to be a promising technique for non-invasive imaging of giant cell arteritis. Mural inflammatory changes of the superficial temporal arteries can be depicted and the cranial involvement pattern can be readily assessed and in combination with MR angiography extracranial involvement can be determined within the same investigation. Aortitis is a feared complication of giant cell arteritis but can be detected and inflammatory stenoses of the aortic branch vessels can also be revealed. In the hands of an experienced operator ultrasonography can be regarded as the non-invasive imaging modality of first choice whereas MRI is more expensive and may not be as widely available. However, its imaging acquisition is standardized and is more observer-independent. Reading of the images is a routine task for a vascular radiologist and larger areas of the vasculature can be simultaneously assessed.


Assuntos
Arterite de Células Gigantes/diagnóstico por imagem , Arterite de Células Gigantes/patologia , Angiografia por Ressonância Magnética/métodos , Reumatologia/tendências , Ultrassonografia/métodos , Animais
8.
Magn Reson Med ; 61(1): 65-74, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19097219

RESUMO

To determine three-dimensional (3D) blood flow patterns in the carotid bifurcation, 10 healthy volunteers and nine patients with internal carotid artery (ICA) stenosis > or =50% were examined by flow-sensitive 4D MRI at 3T. Absolute and mean blood velocities, pulsatility index (PI), and resistance index (RI) were measured in the common carotid arteries (CCAs) by duplex sonography (DS) and compared with flow-sensitive 4D MRI. Furthermore, 3D MRI blood flow patterns in the carotid bifurcation of volunteers and patients before and after recanalization were graded by two independent readers. Blood flow velocities measured by MRI were 31-39% lower than in DS. However, PI and RI differed by only 13-16%. Rating of 3D flow characteristics in the ICA revealed consistent patterns for filling and helical flow in volunteers. In patients with ICA stenosis, 3D blood flow visualization was successfully employed to detect markedly altered filling and helical flow patterns (forward-moving spiral flow) in the ICA bulb and to evaluate the effect of revascularization, which restored filling and helical flow. Our results demonstrate the feasibility of flow-sensitive 4D MRI for the quantification and 3D visualization of physiological and pathological flow patterns in the carotid artery bifurcation.


Assuntos
Velocidade do Fluxo Sanguíneo , Artérias Carótidas/fisiopatologia , Estenose das Carótidas/diagnóstico , Estenose das Carótidas/fisiopatologia , Imageamento Tridimensional/métodos , Imagem Cinética por Ressonância Magnética/métodos , Reologia/métodos , Adulto , Idoso , Algoritmos , Estudos de Viabilidade , Feminino , Humanos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
9.
Arthritis Rheum ; 58(8): 2574-8, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18668559

RESUMO

OBJECTIVE: To compare the diagnostic performance of high-resolution magnetic resonance imaging (MRI) and color-coded duplex sonography (CCDS) in patients with giant cell (temporal) arteritis (GCA). METHODS: Results of high-resolution MRI and CCDS in 59 patients with suspected GCA were compared with the final clinical diagnosis (based on the American College of Rheumatology GCA criteria and a 6-month followup study). Sensitivity, specificity, and positive and negative predictive values (PPV, NPV) were calculated for each method. In 41 of the patients, imaging results were also compared with the findings of a temporal artery (TA) biopsy. RESULTS: Thirty-six of the 59 patients (61%) were ultimately diagnosed as having GCA. Sensitivity of high-resolution MRI and CCDS was 69% and 67%, respectively, specificity was 91% and 91%, PPV was 93% and 92%, and NPV was 66% and 64%, respectively. TA biopsy findings were positive in 24 of the 41 biopsied patients (59%). Sensitivity of high-resolution MRI and CCDS compared with TA biopsy was 83% and 79%, respectively, specificity was 71% and 59%, PPV was 80% and 73%, and NPV was 75% and 67%, respectively. The differences between high-resolution MRI and CCDS were not significant. CONCLUSION: The diagnostic power of high-resolution MRI and CCDS in detecting GCA was comparable. Either of these noninvasive techniques may have value in the evaluation of patients with suspected GCA, and decisions regarding which technique to use may depend on the clinical setting.


Assuntos
Arterite de Células Gigantes/diagnóstico por imagem , Arterite de Células Gigantes/patologia , Imageamento por Ressonância Magnética/métodos , Ultrassonografia Doppler Dupla/métodos , Idoso , Idoso de 80 Anos ou mais , Biópsia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sensibilidade e Especificidade , Artérias Temporais/patologia
10.
J Neurol Neurosurg Psychiatry ; 79(5): 540-6, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-17965147

RESUMO

OBJECTIVES: To evaluate a new three dimensional (3D) MRI protocol for the reliable detection of aortic high risk plaques compared with transoesophageal echocardiography (TOE) and to test the reliability of additional MRI in stroke of undetermined aetiology. METHODS: 74 acute stroke patients were examined by both TOE and MRI at 3 Tesla with special regard to aortic high risk plaques (ie, > OR = 4 mm, superimposed thrombi). ECG synchronised pre- and post-contrast T1 weighted 3D imaging (spatial resolution approximately 1 mm3) covering the thoracic aorta was employed. In plaques > OR = 3 mm, additional two dimensional T2 imaging and time resolved (CINE) imaging sequences were performed. Aetiology of brain ischaemia was classified according to modified TOAST (Trial of Org 10172 in Acute Stroke Treatment) criteria. Aortic high risk embolic sources detected by MRI in patients with cryptogenic stroke were evaluated. RESULTS: Differences in maximum aortic wall thickness for TOE and MRI were not statistically significant for all aortic segments. The overall number of high risk plaques detected by MRI (n = 74) was substantially higher compared with TOE (n = 47). Most noticeably, MRI identified aortic high risk pathologies in 8/26 (30.8%) patients with cryptogenic stroke after standard diagnostics, including TOE (n = 2: dissection or thrombus; n = 6: plaques > OR = 4 mm). CONCLUSIONS: Our results demonstrate the feasibility of this 3D MRI protocol for the reliable detection of aortic high risk plaques in acute stroke patients. Because of improved visualisation of the aortic arch and the detection of additional embolic sources not seen by standard diagnostics, this novel technique may become a valuable tool for future patients with cryptogenic stroke.


Assuntos
Doenças da Aorta/diagnóstico , Aterosclerose/diagnóstico , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Embolia Intracraniana/etiologia , Imagem Cinética por Ressonância Magnética , Imageamento por Ressonância Magnética , Doença Aguda , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Dissecção Aórtica/complicações , Dissecção Aórtica/diagnóstico , Aorta Torácica , Aneurisma Aórtico/complicações , Aneurisma Aórtico/diagnóstico , Doenças da Aorta/complicações , Aterosclerose/complicações , Ecocardiografia Transesofagiana , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Medição de Risco , Trombose/complicações , Trombose/diagnóstico
11.
Eur J Med Res ; 12(12): 595-603, 2007 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-18024271

RESUMO

BACKGROUND: To determine the frequency of essential cardiovascular risk factors in different vascular ocular diseases. - METHODS: We compiled cardiovascular risk factor findings (RFs) from 416 patients with non-inflammatory ocular vascular occlusions in a retrospective study: 134 patients with BRAO, 253 patients with CRAO, and 29 patients with hemi-CRAO. 274 (65.9 %) male and 142 (34.1 %) female patients were examined. Mean age of all patients was 66 years (range: 18-90). The right eye was involved in 221 (53.1 %), left eye in 193 (46.4 %), and both eyes in 2 patients (0.5 %). - RESULTS: Cardiovascular risk factors (RFs) were found in 243 patients. Three hundred and eight (308) out of 406 patients (75.9 %) presented with arterial hypertension. Hypertension was present in 96 patients with BRAO (73.8 %), in 197 patients with CRAO (79.8 %), and in 15 patients with hemi-CRAO (78.9 %). - RFs such as arterial hypertension, carotid artery diseases, diabetes mellitus, hyperlipidemia, hyperuricemia, and chronic smoking did not differ statistically between patients with BRAO, CRAO or hemi--CRAO. But visible emboli in retinal arteries were observed in patients with BRAO (47 %,), or hemi-CRAO (41.4 %), much more often than in patients with CRAO (11.1 %). - CONCLUSIONS: No statistical differences between the RFs of patients with BRAO, CRAO, or hemi-CRAO were noted. We maintain that every patient with retinal arterial obstruction should undergo extensive examination of essential RFs.


Assuntos
Doenças Cardiovasculares/epidemiologia , Oclusão da Artéria Retiniana/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Amaurose Fugaz/complicações , Amaurose Fugaz/diagnóstico , Anticoagulantes/uso terapêutico , Transtornos Cerebrovasculares/complicações , Transtornos Cerebrovasculares/diagnóstico , Feminino , Humanos , Hipertensão/complicações , Hipertensão/diagnóstico , Masculino , Pessoa de Meia-Idade , Femprocumona/uso terapêutico , Oclusão da Artéria Retiniana/tratamento farmacológico , Fatores de Risco
13.
Exp Brain Res ; 180(3): 517-23, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17279380

RESUMO

Migraine affects the autonomous nervous system and a recent investigation has also proposed a severe disturbance of dynamic cerebral blood flow regulation in the middle cerebral artery during spontaneous blood pressure oscillations. This study investigates whether dynamic cerebral autoregulation is impaired in persons with migraine among a normal cohort. Out of 94 adults studied to establish normal values for dynamic autoregulation, 19 suffered from migraine according to IHS criteria (10 of them with aura). Transcranial Doppler sonography and fingerplethysmography were used to determine dynamic autoregulation of both middle cerebral arteries following spontaneous low frequency (0.06-0.12 Hz) blood pressure fluctuations (phase and gain of transfer function, correlation coefficient indices Dx and Mx). No significant differences were found for the low frequency variability of blood pressure (power spectral density) and various indices of dynamic cerebral autoregulation between persons with and without migraine. Moreover, no differences were observed between persons with migraine, with and without aura. This study based on a normal cohort does not support the presence of generally impaired cerebral autoregulation dynamics in persons with migraine. Future studies should focus on posterior circulation and particular cerebellar autoregulation.


Assuntos
Isquemia Encefálica/fisiopatologia , Circulação Cerebrovascular , Homeostase , Artéria Cerebral Média/fisiologia , Transtornos de Enxaqueca/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Pressão Sanguínea/fisiologia , Isquemia Encefálica/complicações , Isquemia Encefálica/diagnóstico por imagem , Circulação Cerebrovascular/fisiologia , Estudos de Coortes , Feminino , Homeostase/fisiologia , Humanos , Hipotensão Intracraniana/complicações , Hipotensão Intracraniana/diagnóstico por imagem , Hipotensão Intracraniana/fisiopatologia , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/diagnóstico por imagem , Transtornos de Enxaqueca/diagnóstico por imagem , Transtornos de Enxaqueca/etiologia , Valor Preditivo dos Testes , Ultrassonografia Doppler Transcraniana , Insuficiência Vertebrobasilar/complicações , Insuficiência Vertebrobasilar/fisiopatologia
14.
Ophthalmologe ; 104(2): 119-26, 2007 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-17235573

RESUMO

Von Hippel-Lindau disease is an important hereditary tumor syndrome with a clear option for effective treatment if diagnosed in time. Interdisciplinary cooperation is the key to successful management. Major components of the disease are retinal capillary hemangioblastomas, hemangioblastomas of cerebellum, brain stem and spine, renal clear cell carcinomas, pheochromocytomas, multiple pancreatic cysts and islet cell carcinomas, tumors of the endolymphatic sac of the inner ear, and cystadenomas of the epididymis and broad ligament. A well structured screening program should be performed at yearly intervals.


Assuntos
Hemangioblastoma/terapia , Hemangioma/terapia , Oftalmologia/história , Patologia/história , Equipe de Assistência ao Paciente , Neoplasias da Retina/terapia , Doença de von Hippel-Lindau/história , Doença de von Hippel-Lindau/terapia , Adenocarcinoma de Células Claras/terapia , Neoplasias das Glândulas Suprarrenais/terapia , Adulto , Diagnóstico Diferencial , Feminino , Alemanha , Hemangioblastoma/diagnóstico , Hemangioma/diagnóstico , História do Século XIX , História do Século XX , Humanos , Relações Interprofissionais , Neoplasias Renais/terapia , Imageamento por Ressonância Magnética , Masculino , Feocromocitoma/terapia , Tomografia por Emissão de Pósitrons , Encaminhamento e Consulta , Neoplasias da Retina/diagnóstico , Suécia , Doença de von Hippel-Lindau/classificação , Doença de von Hippel-Lindau/diagnóstico , Doença de von Hippel-Lindau/diagnóstico por imagem , Doença de von Hippel-Lindau/genética
15.
J Neurol Neurosurg Psychiatry ; 76(12): 1654-8, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16291889

RESUMO

OBJECTIVES: This study investigated (a) the hypothesis that stroke patients with aortic atheroma would show comparable atherosclerotic changes in the carotid arteries, which are easily accessible for ultrasound evaluation and (b) the possibility of carotid duplex sonography as a replacement for transoesophageal echocardiography (TEE) for the exclusion or prediction of relevant aortic plaques. METHODS: In 301 consecutive patients (mean age 62 years) with acute cerebral ischaemia, two dimensional ultrasound measurements were taken of common carotid artery intima media thickness (IMT) and maximal plaque area (PA) and the local degree of internal carotid artery (ICA) stenosis were determined. Maximal aortic wall thickness (AWT) was assessed by TEE. RESULTS: An IMT < or =0.9 mm yielded a negative predictive value (NPV) of 95.8% for exclusion of aortic atheromas > or =4 mm and an NPV of 100% for the exclusion of aortic thrombi. However, positive predictive value of IMT >0.9 mm was low (29.6%), increasing only slightly in the presence of carotid plaques (33%). Incidence of aortic thrombi was significantly higher with > or =50% compared with <50% ICA stenosis (11.3% v 3.9%, respectively). IMT and PA correlated moderately with AWT (r = 0.47, r = 0.53, respectively; p<0.001). Systolic blood pressure, coronary heart disease and peripheral artery disease, increased IMT, and ICA stenosis > or =50% were independently related to AWT > or =4 mm. CONCLUSIONS: A high NPV of normal carotid ultrasound does not support routine TEE for the exclusion of complex aortic plaques as a high risk source of cerebral embolism. However, in patients with carotid atherosclerosis, particularly in those with ICA stenosis > or =50%, TEE should be performed to exclude an additional high risk source for stroke.


Assuntos
Doenças da Aorta/complicações , Aterosclerose/complicações , Artérias Carótidas/diagnóstico por imagem , Artérias Carótidas/patologia , Ecocardiografia Transesofagiana , Acidente Vascular Cerebral/etiologia , Idoso , Isquemia Encefálica , Estenose das Carótidas/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fatores de Risco , Túnica Íntima/diagnóstico por imagem , Túnica Íntima/patologia
16.
Eur J Med Res ; 10(7): 296-304, 2005 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-16055401

RESUMO

BACKGROUND: Ophthalmic complications due to heart tumors are rare. PATIENTS: This case report describes two patients with ocular complications, caused by a suspected cardiac tumor. A 56-year-old woman with arterial hypertension had a severe episode of headache coinciding with an acute loss of vision in her right eye and left-sided hemiparesis. A 20-year-old woman noticed sudden transient visual loss in her right eye. RESULT: The 56-year-old woman had an infarction on the right side of the middle and posterior cerebral arteries and, simultaneously, a central retinal artery occlusion (CRAO) in her right eye. Echocardiography revealed a tumor in the left atrium. The tumor disappeared after treatment with phenprocoumon within a few days. The diagnosis of a cardiac thrombus was made. The 20-year-old woman noticed recurrent episodes of sudden, transient visual loss in her right eye. A branch retinal arterial occlusion (BRAO) in her right eye was diagnosed. Echocardiography revealed a myxoma in the left atrium. The tumor was successfully excised surgically. CONCLUSION: In any vascular disturbance in the eye suspected to be embolic in origin, echocardiography should be carried out in order to exclude the presence of a heart disease.


Assuntos
Neoplasias Cardíacas/complicações , Mixoma/complicações , Células Neoplásicas Circulantes , Oclusão da Artéria Retiniana/etiologia , Adulto , Anticoagulantes/uso terapêutico , Feminino , Átrios do Coração/patologia , Neoplasias Cardíacas/patologia , Neoplasias Cardíacas/cirurgia , Humanos , Pessoa de Meia-Idade , Mixoma/patologia , Mixoma/cirurgia , Células Neoplásicas Circulantes/efeitos dos fármacos , Células Neoplásicas Circulantes/patologia , Femprocumona/uso terapêutico , Oclusão da Artéria Retiniana/tratamento farmacológico , Oclusão da Artéria Retiniana/patologia , Resultado do Tratamento
17.
Electromyogr Clin Neurophysiol ; 45(4): 223-7, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16083145

RESUMO

Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy and extensive surveys have been given on the time course of electrophysiological findings pre- and postoperatively. In patients with clinical and electrophysiological confirmed diagnosis of CTS surgical decompression of the carpal tunnel is a first line treatment and has proven to be successfull in 70 to 90% of all cases. The objective of this work was to study the morphological changes of the median nerve after endoscopic release of the carpal tunnel. We used high resolution ultrasound to quantify flattening of the median nerve and to calculate a flattening ratio before endoscopic release as well as 2 weeks and 3 months postoperatively. Ten patients with clinical and electrophysiological confirmed CTS were included in the study. There was significant normalization of the calculated flattening ratio of the median nerve already 2 weeks after surgical release, whereas nerve conduction studies needed a longer period of time to normalize and thus were still abnormal 3 months postoperatively. We conclude that ultrasound is a simple and excellent objective method for visualizing the morphological recovery of the median nerve very early after decompression surgery. In complex cases with unsatisfactory outcome ultrasonography may prove useful in confirming successfull or failed decompression of the median nerve.


Assuntos
Síndrome do Túnel Carpal/fisiopatologia , Síndrome do Túnel Carpal/cirurgia , Nervo Mediano/fisiopatologia , Condução Nervosa , Síndrome do Túnel Carpal/diagnóstico por imagem , Endoscopia , Seguimentos , Humanos , Nervo Mediano/diagnóstico por imagem , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/fisiopatologia , Ultrassonografia
18.
Stroke ; 36(8): 1684-9, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16020768

RESUMO

BACKGROUND AND PURPOSE: This study investigates dynamic cerebral autoregulation assessed from spontaneous blood pressure (ABP) and cerebral blood flow velocity (CBFV) fluctuations and its time course in acute ischemic stroke. METHODS: Forty patients admitted with acute ischemic stroke in the territory of the middle cerebral artery (MCA) were enrolled. Admission National Institutes of Health Stroke score was 6+/-4. Study 1 was performed within 22 (+/-11) hours and study 2 was performed within 134 (+/-25) hours of ictus. The final analysis comprised 33 and 29 patients for study 1 and study 2, respectively. Twenty-five age- and sex-matched controls were studied. ABP (Finapres method) and CBFV in both MCAs (transcranial Doppler) were recorded over 10 minutes. Correlations between diastolic and mean ABP and CBFV fluctuations were averaged, yielding the correlation coefficient indices (Dx, Mx). Transfer function analysis was applied to obtain phase shift and gain between ABP and CBFV oscillations. RESULTS: No disturbance of autoregulation was indicated by all parameters at study 1. Separate analyses for clinical severity, stroke side, and size did not reveal significant differences for the various autoregulatory indices at study 1 and 2. At study 2, MCA flow velocity was significantly increased on both sides, the autoregulation index Mx was slightly but significantly (P<0.05) worse on both sides in comparison to study 1, and phase showed a trend toward poorer values on affected sides. No significant differences to controls occurred. Clinical outcome in patients completing both studies was good in all but one patient. CONCLUSIONS: Dynamic cerebral autoregulation assessed from spontaneous blood pressure fluctuations does not seem to be relevantly disturbed in early minor MCA stroke. At the subacute stage, slight autoregulatory disturbance may be present.


Assuntos
Pressão Sanguínea , Circulação Cerebrovascular , Telencéfalo/patologia , Adolescente , Adulto , Idoso , Velocidade do Fluxo Sanguíneo , Encéfalo/patologia , Isquemia Encefálica/patologia , Feminino , Frequência Cardíaca , Homeostase , Humanos , Pressão Intracraniana , Masculino , Pessoa de Meia-Idade , Oscilometria , Acidente Vascular Cerebral/patologia , Acidente Vascular Cerebral/terapia , Fatores de Tempo , Resultado do Tratamento , Ultrassonografia Doppler Transcraniana
19.
Stroke ; 35(6): 1381-7, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15087557

RESUMO

BACKGROUND AND PURPOSE: Analysis of dynamic cerebral autoregulation (DCA) from spontaneous blood pressure fluctuations might contribute to prognosis of severe internal carotid artery stenosis, but its response to carotid recanalization has not been investigated so far. This study investigates the effect of carotid endarterectomy or stenting on various DCA parameters. METHODS: In 58 patients with severe unilateral stenosis undergoing carotid endarterectomy (n=41) or stenting (n=17), cerebral blood flow velocity (CBFV, transcranial Doppler) and arterial blood pressure (ABP, Finapres method) were recorded over 10 minutes before and on average 3 days after carotid recanalization. Nineteen patients were additionally examined after 7 months. Correlations between diastolic and mean ABP and CBFV fluctuations were averaged to form the correlation coefficient indices (diastolic [Dx] and mean values [Mx]). Transfer function parameters (low-frequency phase and high-frequency gain between ABP and CBFV oscillations) were calculated over the same 10 minutes. CO2 reactivity was assessed via inhalation of 7% CO2. RESULTS: Before recanalization, all DCA parameters were clearly impaired ipsilaterally compared with contralateral sides. Phase, Dx, and Mx indicated early normalization of DCA after both endarterectomy and stenting. By multiple regression, the degree of DCA improvement was highly significantly related to the extent of impairment before recanalization. No significant change in DCA was found at follow-up. Ipsilateral gain and CO2 reactivity increased significantly less after endarterectomy than after stenting (P<0.05). CONCLUSIONS: Dynamic cerebral dysautoregulation in patients with severe carotid obstruction is readily and completely remedied by carotid recanalization.


Assuntos
Estenose das Carótidas/cirurgia , Córtex Cerebral/irrigação sanguínea , Endarterectomia das Carótidas , Stents , Velocidade do Fluxo Sanguíneo , Pressão Sanguínea , Estenose das Carótidas/fisiopatologia , Homeostase , Humanos , Masculino , Pessoa de Meia-Idade
20.
Nervenarzt ; 75(4): 324-35, 2004 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-15088088

RESUMO

Risk factors are traits which can increase disease risk. In the case of ischemic stroke, risk factors have important roles in primary prevention, clinical practice, and epidemiological research. However, the underlying models, methods, and suited study design are often unknown. Based on interventions, cohort studies, case control studies, and meta-analyses, we give an up-to-date overall survey of the most important established and modifiable risk factors in the primary prevention of ischemic stroke. Each risk factor was assessed using a uniform pattern and systematically analyzed according to intervention type, evidence level, risk reduction, and prevalence.


Assuntos
Medicina Baseada em Evidências/métodos , Medição de Risco/métodos , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/prevenção & controle , Causalidade , Ensaios Clínicos como Assunto , Comorbidade , Humanos , Fatores de Risco
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