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2.
PLoS One ; 14(1): e0210810, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30653589

RESUMO

BACKGROUND: Transcranial Doppler (TCD) was shown to enhance intravascular fibrinolysis by rtPA in ischemic stroke. Studies revealed that catheter-based administration of rtPA induces lysis of intracerebral hemorrhages (ICH). However, it is unknown whether TCD would be suitable to enhance rtPA-induced fibrinolysis in patients with ICH. The aim of this study was to assess the potential of TCD to enhance rtPA-induced fibrinolysis in an in vitro clot system. METHODS: Reproducible human blood clots of 25 ml were incubated in a water bath at 37°C during treatments. They were weighed before and after 6 different treatments: (I) control (incubation only), (II) rtPA only, (III) one Doppler probe, (IV) two Doppler probes placed vis-à-vis, (V) one probe and rtPA and (VI) two probes and rtPA. To quantify lysis of the blood clots and attenuation of the Doppler through a temporal squama acoustic peak rarefaction pressure (APRP) was measured in the field of the probes. Temperature was assessed to evaluate possible side effects. RESULTS: Clot weight was reduced in all groups. The control group had the highest relative end weight of 70.2%±7.2% compared to all other groups (p<0,0001). Most efficient lysis was achieved using (VI) 2 probes and rtPA 36.3%±4.4% compared to (II, III, IV) (p<0.0001; p = 0.0002; p = 0.048). APRP was above lysis threshold (535.5±7.2 kPa) using 2 probes even through the temporal squama (731.6±32.5 kPa) (p = 0.0043). There was a maximal temperature elevation of 0.17±0.07°C using both probes. CONCLUSIONS: TCD significantly enhances rtPA-induced lysis of blood clots, and the effect is amplified by using multiple probes. Our results indicate that bitemporal TCD insonation of hematomas could be a new and safe approach to enhance fibrinolysis of ICH´s treated with intralesional catheter and rtPA.


Assuntos
Hemorragia Cerebral/terapia , Terapia Trombolítica/métodos , Ativador de Plasminogênio Tecidual/uso terapêutico , Terapia por Ultrassom/métodos , Terapia Combinada , Fibrinólise/efeitos dos fármacos , Humanos , Técnicas In Vitro , Modelos Cardiovasculares , Estudo de Prova de Conceito , Terapia por Ultrassom/instrumentação , Ultrassonografia Doppler Transcraniana/instrumentação
3.
J Neurol Sci ; 392: 122-125, 2018 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-30055383

RESUMO

PURPOSE: We developed a novel probe (pastable soft ultrasound probe; PSUP) attached to the neck for right-to-left shunt (RLS) detection. The purpose of this study was to evaluate the diagnostic ability of the PSUP for RLS detection by comparison with transesophageal echocardiography (TEE). METHODS: The subjects were patients with ischemic strokes and transient ischemic attacks who underwent TEE. Based on TEE, patients with patent foramen ovale (PFO) were divided into two groups by the number of microbubbles (MBs): small PFO (1-29 MBs) and large PFO (≥30 MBs). Then, PSUP examination of one common carotid artery (CCA) was started using a procedure similar to TEE. RLS was diagnosed by PSUP when one or more microembolic signals were found in the CCA. The detection rate by size of PFO was compared between TEE and PSUP, and the diagnostic accuracy of PSUP was calculated. RESULTS: From May 2014 to July 2016, 84 patients (63 males, median age 63 years) were included; 41 (49%) were diagnosed with PFO by TEE, while PSUP detected PFO in 31 (37%). Using TEE findings as the reference, PSUP for PFO showed sensitivity of 68%, specificity of 93%, and accuracy of 81%. On TEE, 22 patients had large PFOs, and 19 patients had small PFOs. The PSUP could identify large PFOs in grade I and II of International Consensus Criteria more accurately than small ones (58 and 86% vs. 29 and 14%, P = 0.003). CONCLUSIONS: The PSUP has considerable accuracy for diagnosing large PFOs. PSUP should play an important role in detecting large PFOs.


Assuntos
Ecocardiografia Transesofagiana/métodos , Forame Oval Patente/diagnóstico por imagem , Ultrassonografia Doppler Transcraniana/métodos , Idoso , Meios de Contraste/metabolismo , Feminino , Forame Oval Patente/etiologia , Humanos , Ataque Isquêmico Transitório/complicações , Masculino , Pessoa de Meia-Idade , Pescoço/diagnóstico por imagem , Ultrassonografia Doppler Transcraniana/instrumentação , Manobra de Valsalva/fisiologia
4.
J Neural Eng ; 15(5): 056019, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30021931

RESUMO

OBJECTIVE: In this paper, we introduce a novel hybrid brain-computer interface (BCI) system that measures electrical brain activity as well as cerebral blood velocity using electroencephalography (EEG) and functional transcranial Doppler ultrasound (fTCD) respectively in response to flickering mental rotation (MR) and flickering word generation (WG) cognitive tasks as well as a fixation cross that represents the baseline. This work extends our previous approach, in which we showed that motor imagery induces simultaneous changes in EEG and fTCD to enable task discrimination; and hence, provides a design approach for a hybrid BCI. Here, we show that instead of using motor imagery, the proposed visual stimulation technique enables the design of an EEG-fTCD based BCI with higher accuracy. APPROACH: Features based on the power spectrum of EEG and fTCD signals were calculated. Mutual information and support vector machines were used for feature selection and classification purposes. MAIN RESULTS: EEG-fTCD combination outperformed EEG by 4.05% accuracy for MR versus baseline problem and by 5.81% accuracy for WG versus baseline problem. An average accuracy of 92.38% was achieved for MR versus WG problem using the hybrid combination. Average transmission rates of 4.39, 3.92, and 5.60 bits min-1 were obtained for MR versus baseline, WG versus baseline, and MR versus WG problems respectively. SIGNIFICANCE: In terms of accuracy, the current visual presentation outperforms the motor imagery visual presentation we designed before for the EEG-fTCD system by 10% accuracy for task versus task problem. Moreover, the proposed system outperforms the state of the art hybrid EEG-fNIRS BCIs in terms of accuracy and/or information transfer rate. Even though there are still limitations of the proposed system, such promising results show that the proposed hybrid system is a feasible candidate for real-time BCIs.


Assuntos
Interfaces Cérebro-Computador , Eletroencefalografia/instrumentação , Ultrassonografia Doppler Transcraniana/instrumentação , Adulto , Cognição/fisiologia , Eletroencefalografia/classificação , Feminino , Fixação Ocular/fisiologia , Humanos , Imaginação/fisiologia , Masculino , Estimulação Luminosa , Desempenho Psicomotor/fisiologia , Reprodutibilidade dos Testes , Rotação , Máquina de Vetores de Suporte , Ultrassonografia Doppler Transcraniana/classificação
5.
Artigo em Inglês | MEDLINE | ID: mdl-29733278

RESUMO

For investigating human transcranial ultrasound imaging (TUI) through the temporal bone, an intact human skull is needed. Since it is complex and expensive to obtain one, it requires that experiments are performed without excision or abrasion of the skull. Besides, to mimic blood circulation for the vessel target, cellulose tubes generally fit the vessel simulation with straight linear features. These issues, which limit experimental studies, can be overcome by designing a 3-D-printed skull model with acoustic and dimensional properties that match a real skull and a vessel model with curve and bifurcation. First, the optimal printing material which matched a real skull in terms of the acoustic attenuation coefficient and sound propagation velocity was identified at 2-MHz frequency, i.e., 7.06 dB/mm and 2168.71 m/s for the skull while 6.98 dB/mm and 2114.72 m/s for the printed material, respectively. After modeling, the average thickness of the temporal bone in the printed skull was about 1.8 mm, while it was to 1.7 mm in the real skull. Then, a vascular phantom was designed with 3-D-printed vessels of low acoustic attenuation (0.6 dB/mm). It was covered with a porcine brain tissue contained within a transparent polyacrylamide gel. After characterizing the acoustic consistency, based on the designed skull model and vascular phantom, vessels with inner diameters of 1 and 0.7 mm were distinguished by resolution enhanced imaging with low frequency. Measurements and imaging results proved that the model and phantom are authentic and viable alternatives, and will be of interest for TUI, high intensity focused ultrasound, or other therapy studies.


Assuntos
Imagens de Fantasmas , Impressão Tridimensional , Crânio/diagnóstico por imagem , Ultrassonografia Doppler Transcraniana/instrumentação , Ultrassonografia Doppler Transcraniana/métodos , Animais , Humanos , Processamento de Imagem Assistida por Computador , Processamento de Sinais Assistido por Computador , Suínos
6.
Phys Med Biol ; 63(10): 105016, 2018 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-29667598

RESUMO

Transcranial focused ultrasound (FUS) is a non-invasive technique for therapy and study of brain neural activation. Here we report on the design and characterization of a new MR-guided FUS transducer for neuromodulation in non-human primates at 650 kHz. The array is randomized with 128 elements 6.6 mm in diameter, radius of curvature 7.2 cm, opening diameter 10.3 cm (focal ratio 0.7), and 46% coverage. Simulations were used to optimize transducer geometry with respect to focus size, grating lobes, and directivity. Focus size and grating lobes during electronic steering were quantified using hydrophone measurements in water and a three-axis stage. A novel combination of optical tracking and acoustic mapping enabled measurement of the 3D pressure distribution in the cortical region of an ex vivo skull to within ~3.5 mm of the surface, and allowed accurate modelling of the experiment via non-homogeneous 3D acoustic simulations. The data demonstrates acoustic focusing beyond the skull bone, with the focus slightly broadened and shifted proximal to the skull. The fabricated design is capable of targeting regions within the S1 sensorimotor cortex of macaques.


Assuntos
Imagem por Ressonância Magnética/métodos , Vias Neurais , Crânio/diagnóstico por imagem , Crânio/efeitos da radiação , Estimulação Elétrica Nervosa Transcutânea/métodos , Ultrassonografia Doppler Transcraniana/instrumentação , Ultrassonografia Doppler Transcraniana/métodos , Animais , Humanos , Primatas , Crânio/patologia
7.
Acta Neurochir Suppl ; 126: 111-114, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29492544

RESUMO

OBJECTIVE: Practical deficiencies related to conventional transcranial Doppler (TCD) sonography have restricted its use and applicability. This work seeks to mitigate several such constraints through the development of a wearable, electronically steered TCD velocimetry system, which enables noninvasive measurement of cerebral blood flow velocity (CBFV) for monitoring applications with limited operator interaction. MATERIALS AND METHODS: A highly-compact, discrete prototype system was designed and experimentally validated through flow phantom and preliminary human subject testing. The prototype system incorporates a custom two-dimensional transducer array and multi-channel transceiver electronics, thereby facilitating acoustic beamformation via phased array operation. Electronic steering of acoustic energy enables algorithmic system controls to map Doppler power throughout the tissue volume of interest and localize regions of maximal flow. Multi-focal reception permits dynamic vessel position tracking and simultaneous flow velocimetry over the time-course of monitoring. RESULTS: Experimental flow phantom testing yielded high correlation with concurrent flowmeter recordings across the expected range of physiological flow velocities. Doppler power mapping has been validated in both flow phantom and preliminary human subject testing, resulting in average vessel location mapping times <14 s. Dynamic vessel tracking has been realized in both flow phantom and preliminary human subject testing. CONCLUSIONS: A wearable prototype CBFV measurement system capable of autonomous vessel search and tracking has been presented. Although flow phantom and preliminary human validation show promise, further human subject testing is necessary to compare velocimetry data against existing commercial TCD systems. Additional human subject testing must also verify acceptable vessel search and tracking performance under a variety of subject populations and motion dynamics-such as head movement and ambulation.


Assuntos
Velocidade do Fluxo Sanguíneo/fisiologia , Circulação Cerebrovascular/fisiologia , Equipamentos e Provisões , Artéria Cerebral Média/diagnóstico por imagem , Ultrassonografia Doppler Transcraniana/instrumentação , Dispositivos Eletrônicos Vestíveis , Voluntários Saudáveis , Humanos , Imagens de Fantasmas
8.
J Ultrasound ; 21(1): 1-16, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29429015

RESUMO

Multimodality monitoring is a common practice in caring for neurocritically ill patients, and consists mainly in clinical assessment, intracranial pressure monitoring and using several imaging methods. Of these imaging methods, transcranial Doppler (TCD) is an interesting tool that provides a non-invasive, portable and radiation-free way to assess cerebral circulation and diagnose and follow-up (duplex method) intracranial mass-occupying lesions, such as hematomas and midline shift. This article reviews the basics of TCD applied to neurocritical care patients, offering a rationale for its use as well as tips for practitioners.


Assuntos
Cuidados Críticos , Ultrassonografia Doppler Transcraniana , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Circulação Cerebrovascular , Cuidados Críticos/métodos , Humanos , Ultrassonografia Doppler Transcraniana/instrumentação , Ultrassonografia Doppler Transcraniana/métodos
9.
J Colloid Interface Sci ; 501: 282-293, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28460221

RESUMO

A single-step fabrication method, coaxial electrohydrodynamic atomization (CEHDA), was developed to synthesize drug-loaded microbubbles (MBs) for combination treatment of ischemic stroke. The bioactivity of therapeutic agent (tPA, tissue plasminogen activator) after preparation was evaluated, showing that CEHDA could be very promising method for producing MBs with therapeutic functions. The bubble performance and tPA release profiles were also examined by exposing the bubbles to 2MHz ultrasound of various intensities. The results showed that the mean diameter of tPA-loaded MBs was found to fluctuate about its original diameter when exposed to ultrasound and higher intensity ultrasound was more effective in triggering the burst of CEHDA MBs. High ultrasound-triggered bubble disintegration effectiveness in a short period (first 5min) fits well with the requirement of short ultrasound exposure time for human brain. Moreover, a numerical model was also applied to investigate the stability of the fabricated MBs in the bloodstream. It was found that MB dissolution time increased with initial radius, decreased with initial surface tension and increased with initial shell resistance but it was barely affected by the average excessive bloodstream pressure.


Assuntos
Sistemas de Liberação de Medicamentos/instrumentação , Microbolhas , Fosfolipídeos/química , Ativador de Plasminogênio Tecidual/administração & dosagem , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/terapia , Liberação Controlada de Fármacos , Desenho de Equipamento , Humanos , Modelos Moleculares , Ativador de Plasminogênio Tecidual/química , Ultrassonografia Doppler Transcraniana/instrumentação
10.
Zhongguo Yi Liao Qi Xie Za Zhi ; 41(6): 446-449, 2017 Nov 30.
Artigo em Chinês | MEDLINE | ID: mdl-29862708

RESUMO

The fundamental concept, measuring and calculating of Transcranial Doppler Diagnostic & Monitor System acoustic output power are introduced according to hydrophone scanning method and pulsing sequences principle. Then, the feasibility of the method is demonstrated. Finally, the detail calculating method of Transcranial Doppler Diagnostic & Monitor System has been derived.


Assuntos
Transdutores , Ultrassonografia Doppler Transcraniana/instrumentação , Acústica , Monitorização Fisiológica
11.
Ultraschall Med ; 38(1): 44-50, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26422667

RESUMO

Purpose To quantify the pressure exerted on the maternal abdominal wall during ultrasound examination and evaluate its effect on the fetal middle cerebral artery (MCA) peak systolic velocity (PSV). Materials and Method Gravid women with singleton pregnancies in their 2nd-3 rd trimester undergoing fetal sonographic evaluation for various indications were recruited. Each subject underwent transabdominal US measuring fetal distance from the probe, abdominal thickness, amniotic fluid index and biophysical profile. The applied pressure was measured simultaneously using an electronic pressure sensor attached directly to the US probe. For each subject baseline values of the pressure required for proper visualization were obtained. Fetal MCA was then demonstrated using color Doppler US. The PSV was measured at different pressure ranges with each subject used as her own control. Care was taken not to exceed the baseline pressure for each subject. Results 29 women were recruited. 24 subjects (82.7 %) demonstrated a statistically significant positive correlation between the pressure exerted and MCA-PSV (R-0.37, p < 0.0001). Of these, 4 subjects (13.8 % of study population) demonstrated elevation of PSV values above 1.29 MOM and 5 subjects (17.2 %) demonstrated elevation of PSV values above 1.5 MOM for gestational age with increasing pressure. In total, 9 subjects (31 %) demonstrated significant changes in the MCA-PSV measurements (owing to increase in pressure applied) that could potentially falsely influence clinical obstetric diagnosis and management. Conclusion The pressure exerted on the maternal abdominal wall during US examination is an important parameter, producing clinically significant measurable changes in fetal MCA hemodynamics. Further study is needed in order to demonstrate the potential effect of pressure as a parameter influencing the diagnostic accuracy of the MCA-PSV in the setting of fetal anemia.


Assuntos
Parede Abdominal/diagnóstico por imagem , Velocidade do Fluxo Sanguíneo/fisiologia , Artéria Cerebral Média/diagnóstico por imagem , Artéria Cerebral Média/fisiopatologia , Sístole/fisiologia , Ultrassonografia Doppler Transcraniana/instrumentação , Ultrassonografia Doppler Transcraniana/métodos , Ultrassonografia Pré-Natal/instrumentação , Ultrassonografia Pré-Natal/métodos , Feminino , Humanos , Gravidez , Segundo Trimestre da Gravidez , Terceiro Trimestre da Gravidez , Ultrassonografia Doppler de Pulso
12.
Radiología (Madr., Ed. impr.) ; 58(supl.2): 129-141, mayo 2016. ilus
Artigo em Espanhol | IBECS | ID: ibc-153299

RESUMO

La ecografía transfontanelar es una técnica diagnóstica ampliamente utilizada en el estudio de la neuroanatomía y patología propia del encéfalo neonatal gracias a sus múltiples ventajas, como la ausencia de radiaciones, disponibilidad, portabilidad y bajo coste. El desarrollo de equipos más potentes junto con la mejora de sondas microcurvadas y lineares de distintas frecuencias ha permitido una ostensible mejoría en la calidad de la imagen ecográfica del cerebro neonatal. Para obtener el máximo rendimiento de esta técnica es importante familiarizarse con la anatomía y patología neurológica de este grupo de edad. De hecho, es la primera técnica en el estudio de complicaciones a corto y medio plazo de los recién nacidos prematuros. En el neonato a término es muy útil para abordar múltiples situaciones clínicas, ya que permite seleccionar qué pacientes se beneficiarán de otras técnicas invasivas, más caras o que requieran sedación, como la resonancia magnética. Sus desventajas son ser operador dependiente y la necesidad de una adecuada ventana acústica. Tiene limitaciones en el estudio de la patología traumática obstétrica, la valoración de la patología malformativa compleja y el daño de la sustancia blanca. Con los conocimientos básicos de neurología neonatal, el equipamiento apropiado y una técnica cuidadosa que incluya el uso de distintas fontanelas, es un método fiable que permite el diagnóstico y seguimiento de patologías tanto congénitas como adquiridas en el neonato (AU)


Transfontanellar ultrasound is widely used to study neonatal neuroanatomy and disease. This technique has many advantages, such as the absence of ionizing radiation and its wide availability, portability, and low cost. The development of more powerful ultrasound scanners and improved microcurved and linear probes of different frequencies have resulted in improved image quality. To take full advantage of this technique, it is important to know the normal and pathologic anatomy in neonates. Transfontanellar ultrasound is the first-line technique for studying short-term and mid-term complications in premature newborns. In full-term newborns, it is very useful in many clinical situations, making it possible to select which patients will benefit from other techniques that are more invasive or more expensive, or that require sedation, such as MRI. The disadvantages of the technique are that it is operator dependent and that an appropriate acoustic window is necessary. It also has limitations in the study of obstetric trauma, in the evaluation of complex malformations, and in the assessment of damage to white matter. With a basic understanding of neonatal neurology, the appropriate equipment, and a careful technique taking advantage of the different fontanels, transfontanellar ultrasound is a reliable method that makes it possible to diagnose and follow up both congenital and acquired conditions in neonates (AU)


Assuntos
Humanos , Masculino , Feminino , Recém-Nascido , Fontanelas Cranianas , Ecoencefalografia/instrumentação , Ecoencefalografia/métodos , Ultrassonografia Doppler Transcraniana/instrumentação , Ultrassonografia Doppler Transcraniana/métodos , Ultrassonografia Doppler Transcraniana , Ultrassonografia Doppler Transcraniana/classificação , Ultrassonografia Doppler Transcraniana/ética , Ultrassonografia Doppler Transcraniana/normas , Doenças do Prematuro , Recém-Nascido Prematuro/fisiologia , Ultrassonografia Doppler de Pulso/métodos
13.
Scand J Clin Lab Invest ; 76(1): 82-7, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26503121

RESUMO

INTRODUCTION: Continuous non-invasive monitoring of cerebral blood flow (CBF) may be important during anaesthesia and several options are available. We evaluated the CerOx monitor that employs ultrasound tagged near infrared spectroscopy to estimate changes in a CBF index (CFI). METHODS: Seven healthy males (age 21-26 years) hyperventilated and were administered phenylephrine to increase mean arterial pressure by 20-30 mmHg. Frontal lobe tissue oxygenation (ScO2) and CFI were obtained using the CerOx and mean blood flow velocity in the middle cerebral artery (MCAv mean) was determined by transcranial Doppler. Blood flow in the internal and external carotid artery (ICAf and ECAf) was determined using duplex ultrasonography and forehead skin blood flow (SkBF) and oxygenation (S skin O2) by laser Doppler and white light spectroscopy. RESULTS: During hyperventilation MCAv mean and ICAf decreased by 44% (median; interquartile range 40-49; p = 0.016) and 46% (40-53; p = 0.03), respectively. Conversely, CFI increased by 9% (2-31; p = 0.016), while no significant change was observed in ScO2. SkBF increased by 19% (9-53; p = 0.016) and S skin O2 by 6% (1-7; p = 0.047), although ECAf was unchanged. Administration of phenylephrine was not associated with any changes in MCAv mean, ICAf, ECAf, ScO2, SkBF, S skin O2, or CFI. CONCLUSION: The CerOx was able to detect a stable CBF during administration of phenylephrine. However, during hyperventilation MCAv mean and ICAf decreased while CFI increased, likely due to an increase in superficial tissue oxygenation. Thus, CFI does not provide an unbiased evaluation of changes in CBF.


Assuntos
Circulação Cerebrovascular , Hiperventilação/sangue , Monitorização Fisiológica/métodos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Ultrassonografia Doppler Dupla/métodos , Adulto , Velocidade do Fluxo Sanguíneo , Artéria Carótida Externa/diagnóstico por imagem , Artéria Carótida Interna/diagnóstico por imagem , Circulação Cerebrovascular/efeitos dos fármacos , Humanos , Hiperventilação/tratamento farmacológico , Masculino , Artéria Cerebral Média , Monitorização Fisiológica/instrumentação , Oxigênio/sangue , Fenilefrina/uso terapêutico , Espectroscopia de Luz Próxima ao Infravermelho/instrumentação , Ultrassonografia Doppler Dupla/instrumentação , Ultrassonografia Doppler Transcraniana/instrumentação , Ultrassonografia Doppler Transcraniana/métodos , Adulto Jovem
14.
Neurología (Barc., Ed. impr.) ; 30(8): 496-501, oct. 2015. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-144219

RESUMO

Introducción: La hiposmia y la hiperecogenicidad de la sustancia negra (SN+) son marcadores característicos de la enfermedad de Parkinson (EP), aunque su valor diagnóstico de forma aislada puede ser limitado. Se evalúa la prevalencia combinada de ambos marcadores en pacientes diagnosticados de enfermedad de Parkinson (EP) y su rentabilidad diagnóstica frente a una muestra con temblor esencial (TE) y otra de sujetos sanos. Métodos: Se incluyó a pacientes con diagnóstico de EP y TE procedentes de nuestra consulta externa. La olfación se evaluó con el test de identificación de olores Sniffin Sticks test (SS-12) y la evaluación de la sustancia negra mediante dúplex transcraneal. Resultados: Se evaluó a 98 individuos, 30 con diagnóstico de EP, 21 con TE y 47 controles. Las prevalencias de hiposmia (SS-12 < 8) e hiperecogenicidad de SN (área > 0,24 cm2) fueron del 70 y el 83,3% en EP, el 33,3 y el 9,5% en TE y el 17 y el 10,6% en los controles, respectivamente. La combinación de ambos marcadores estaba presente en el 63% de los pacientes con EP y en ninguno de los pacientes con TE y solo en 2 de los controles. Conclusiones: La evaluación combinada de la evaluación olfativa mediante el SS-12 y de la sustancia negra mediante ecografía, 2 test rápidos, inocuos y accesibles, mejora la especificidad aislada que cada marcador tiene en el diagnóstico de la EP frente a pacientes con TE o controles. Dado que ambos marcadores se han descrito en fases muy precoces de la EP, su aplicación podría ayudarnos en su diagnóstico precoz (AU)


Introduction: Hyposmia and substantia nigra hyperechogenicity (SN+) are characteristic markers of Parkinson's disease (PD), although their diagnostic value in isolation may be limited. We evaluated the combined prevalence of both disorders in patients diagnosed with PD and assessed their diagnostic yield compared to a sample with essential tremor (ET) and another group of healthy subjects. Methods: Patients diagnosed with PD and ET and treated in our outpatient clinic were enrolled. Olfaction was assessed using the 'Sniffin Sticks' odour identification test (SS-12) and hyperechogenicity of the substantia nigra (SN+) was assessed by transcranial duplex ultrasound. Results: A total of 98 subjects were analysed, comprising 30 with PD, 21 with ET, and 47 controls. The respective prevalence rates of hyposmia (SS-12 < 8) and SN+ (area > .24 cm2) were 70% and 83.3% in PD, 33.3% and 9.5% in ET, and 17% and 10.6% in controls. Both markers were present in 63% of patients with PD, none of the patients with ET, and only 2 of the controls. Conclusions: Combined use of substantia nigra sonography and olfactory testing with SS-12, two rapid, safe, and accessible tests, was more specific than each isolated marker for distinguishing patients with PD from patients with ET and control subjects. Since both markers have been described in very early phases of PD, combined use may be helpful in providing early diagnosis of PD (AU)


Assuntos
Feminino , Humanos , Masculino , Substância Negra/patologia , Doença de Parkinson/diagnóstico , Diagnóstico Precoce , Transtornos do Olfato/complicações , Transtornos do Olfato/diagnóstico , Valor Preditivo dos Testes , Ultrassonografia Doppler Transcraniana/instrumentação , Ultrassonografia Doppler Transcraniana , Odorantes/análise , Olfato/fisiologia , Análise de Variância , Estudos de Casos e Controles , Curva ROC
16.
J Neurol Surg A Cent Eur Neurosurg ; 76(6): 451-5, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26140418

RESUMO

INTRODUCTION: Intraoperative micro-Doppler (IOMD), intraoperative digital substraction angiography (DSA), and microscope-integrated indocyanine green angiography are methods that guide neurosurgical resection of arteriovenous malformations (AVMs) in the brain and minimize the trauma of healthy tissue. In this study we emphasize the use of IOMD in AVM surgery, analyzing the advantages and the limitations of this method. Patients and METHODS: A total of 32 patients were diagnosed with an AVM. Supplying arteries and draining veins were analyzed regarding hemodynamic profiles, flow velocities, pulsatility index (PI), and resistance index (RI). Venous drainages were accompanied by arterial blood flow disturbances that showed typical characteristics in all cases. We set an angle of 60 degrees between the examined vessel and the probe to achieve a more reliable and comparable measurement. Postoperative DSA was performed in all patients. RESULTS: Supplying arterial blood vessels of AVMs could be identified by their characteristic blood flow profiles with PI < 0.7 and RI < 0.55. Drainage veins in all 32 cases showed normalized venous flow patterns without arterial flow turbulences at the end of the surgical procedure. Postoperative DSA revealed a residual AVM in one patient. CONCLUSIONS: IOMD constitutes a safe, accurate, and low-cost imaging modality for evaluating blood flow velocities and for optimal stepwise AVM elimination without unnecessary sacrifice of veins. PI and RI are reliable parameters in diagnosing cerebrovascular malformations, but systolic and diastolic flow velocities may vary to a greater extent. This phenomenon has never been elucidated previously and therefore needs to be emphasized when using this technique intraoperatively.


Assuntos
Fístula Arteriovenosa/diagnóstico por imagem , Fístula Arteriovenosa/cirurgia , Malformações Arteriovenosas Intracranianas/diagnóstico por imagem , Malformações Arteriovenosas Intracranianas/cirurgia , Monitorização Intraoperatória/métodos , Ultrassonografia Doppler Transcraniana/métodos , Angiografia Digital , Angiografia Cerebral , Humanos , Monitorização Intraoperatória/instrumentação , Resultado do Tratamento , Ultrassonografia Doppler Transcraniana/instrumentação
17.
J Vis Exp ; (96): e52238, 2015 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-25742241

RESUMO

Cranial ultrasound (CUS) is a reputable tool for brain imaging in critically ill neonates. It is safe, relatively cheap and easy to use, even when a patient is unstable. In addition it is radiation-free and allows serial imaging. CUS possibilities have steadily expanded. However, in many neonatal intensive care units, these possibilities are not optimally used. We present a comprehensive approach for neonatal CUS, focusing on optimal settings, different probes, multiple acoustic windows and Doppler techniques. This approach is suited for both routine clinical practice and research purposes. In a live demonstration, we show how this technique is performed in the neonatal intensive care unit. Using optimal settings and probes allows for better imaging quality and improves the diagnostic value of CUS in experienced hands. Traditionally, images are obtained through the anterior fontanel. Use of supplemental acoustic windows (lambdoid, mastoid, and lateral fontanels) improves detection of brain injury. Adding Doppler studies allows screening of patency of large intracranial arteries and veins. Flow velocities and indices can be obtained. Doppler CUS offers the possibility of detecting cerebral sinovenous thrombosis at an early stage, creating a window for therapeutic intervention prior to thrombosis-induced tissue damage. Equipment, data storage and safety aspects are also addressed.


Assuntos
Encéfalo/anatomia & histologia , Ecoencefalografia/métodos , Encéfalo/irrigação sanguínea , Encefalopatias/diagnóstico por imagem , Ecoencefalografia/instrumentação , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Ultrassonografia Doppler Transcraniana/instrumentação , Ultrassonografia Doppler Transcraniana/métodos
18.
J Stroke Cerebrovasc Dis ; 23(10): 2730-5, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25238929

RESUMO

BACKGROUND: Stroke is a severe emergent cardiologic disease for death and permanent disability. Ultrasound exposure could noninvasively enhance the clot lysis of tissue plasminogen activator (tPA) with the presence of microbubbles (MBs). A variety of sonography systems are available in the market, and whether sonothrombolysis is only successful using specific devices is unknown. METHODS: Three commercial ultrasound systems (Siemens, Philips, and SonoSite) were characterized first for their acoustic field, and then the thrombolysis efficiencies were evaluated using the same in vitro setup and protocol. RESULTS: Despite different acoustic fields and pressure waveforms at the focus, similar sonothrombolysis abilities with tPA and MBs were found, and the presence of temporal bone will worsen the performance slightly (by about 10% in the clot lysis). CONCLUSIONS: Therefore, it suggests that satisfactory sonothrombolysis in vivo or in clinics could be achieved using a variety of commercial ultrasound devices if the acoustic output is sufficiently strong.


Assuntos
Microbolhas , Sonicação/métodos , Acidente Vascular Cerebral/terapia , Terapia Trombolítica/métodos , Terapia por Ultrassom/métodos , Ultrassonografia Doppler Transcraniana/instrumentação , Idoso , Idoso de 80 Anos ou mais , Terapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/tratamento farmacológico , Ativador de Plasminogênio Tecidual/uso terapêutico , Resultado do Tratamento , Ultrassonografia Doppler Transcraniana/métodos
19.
Neurol India ; 62(1): 62-5, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24608457

RESUMO

OBJECTIVES: The objective of the following study is to determine the effect of continuous insonation using 2-MHz transcranial Doppler-ultrasound (TCD-US) on the recanalization rate and the short-term outcome in subjects with acute ischemic stroke due to middle cerebral artery (MCA) occlusion. MATERIALS AND METHODS: A total of 42 patients with acute ischemic stroke due to MCA occlusion within 24 h were recruited and randomly allotted to two groups (21 patients in each group). Group 1 included patients who received 1 h continuous TCD-US for MCA and Group 2 included patients who did not receive 1 h continuous TCD-US. Patients in both groups were received MCA insonation and TCD study to measure mean flow velocity (MFV) in MCA one after the initial study at 20 and 60 min. All patients received aspirin (150-325 mg). The clinical course during hospital stay was assessed before and after 1 h of US insonation, at 24 h after symptom onset using the National Institutes of Health Stroke Scale. RESULTS: Change in MFV after insonation for Group 1 in comparison to Group 2 at 3 time points was significantly high (P < 0.001). CONCLUSION: Sonothrombolysis is a therapeutic option to improve the outcomes in patients with acute ischemic stroke due to MCA occlusion.


Assuntos
Infarto da Artéria Cerebral Média/diagnóstico por imagem , Acidente Vascular Cerebral/diagnóstico por imagem , Ultrassonografia Doppler Transcraniana/métodos , Adulto , Idoso , Aspirina/administração & dosagem , Velocidade do Fluxo Sanguíneo/fisiologia , Feminino , Fibrinolíticos/administração & dosagem , Humanos , Infarto da Artéria Cerebral Média/complicações , Infarto da Artéria Cerebral Média/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/etiologia , Resultado do Tratamento , Ultrassonografia Doppler Transcraniana/instrumentação
20.
Ultrasound Med Biol ; 40(4): 828-36, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24462159

RESUMO

In theory, the power of a trans-cranial Doppler signal may be used to measure changes in blood flow and vessel diameter in addition to velocity. In this study, a flow index (FI) of relative changes in blood flow was derived from frequency-weighted Doppler power signals. The FI, plotted against velocity, was calibrated to the zero intercept with absent flow to reduce the effects of non-uniform vessel insonation. An area index was also calculated. FIs were compared with actual flow in four silicone tubes of different diameter at increasing flow rates and increasing hematocrit (Hct) in a closed-loop phantom model. FI values were strongly correlated with actual flow, at constant Hct, but varied substantially with changes in Hct. Percentage changes in area indexes, relative to the 4-mm tube, were strongly correlated with tube cross-sectional area. The implications of these results for in vivo use are discussed.


Assuntos
Circulação Cerebrovascular/fisiologia , Hematócrito/métodos , Hematócrito/normas , Interpretação de Imagem Assistida por Computador/métodos , Ultrassonografia Doppler Transcraniana/métodos , Ultrassonografia Doppler Transcraniana/normas , Algoritmos , Velocidade do Fluxo Sanguíneo/fisiologia , Encéfalo/fisiologia , Calibragem , Humanos , Interpretação de Imagem Assistida por Computador/normas , Imagens de Fantasmas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Ultrassonografia Doppler Transcraniana/instrumentação
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