Encuesta sobre usos y prácticas de Doppler transcraneal en pacientes neurocríticos en unidades de cuidados intensivos pediátricos de Argentina / Survey on the use and practice of transcranial Doppler ultrasound in neurocritical patients in pediatric intensive care Units in Argentina

Introducción. El uso del Doppler transcraneal (DTC) en pacientes neurocríticos se reporta cada vez más en las terapias intensivas pediátricas. El objetivo de esta encuesta es conocer los usos y prácticas del DTC en la atención neurocrítica y el proceso de formación del personal que realiza el estudio. Materiales y métodos. Encuesta a profesionales de 23 unidades de terapia intensiva pediátrica de Argentina. Resultados. Porcentaje de respuesta del 86 %. Se utilizó en sospecha de muerte encefálica (n = 20), trauma de cráneo (n = 16) y accidente cerebrovascular (n = 16). El intensivista pediátrico es quien realiza los estudios (n = 13/20). Los encuestados utilizan el Doppler para decidir conductas y tratamientos, comenzar el proceso de evaluación de muerte encefálica, solicitar tomografía de cerebro y manejar la presión de perfusión cerebral con vasopresores. Conclusión. Todos los encuestados utilizan los hallazgos del DTC para guiar tratamientos o conductas. La mitad de los encuestados está poco conforme con la capacitación recibida.

Introduction. The use of transcranial Doppler (TCD) ultrasoundin neurocritical patients is reported to be increasingly common in pediatric intensive care units. The objective of this survey was to know about the use and practice of TCD ultrasound in neurocritical care and the training process of staff members performing it. Materials and methods. Survey administered to providers from 23 pediatric intensive care units of Argentina. Results. The percentage of response was 86%. TCD ultrasound was used for suspected brain death (n = 20), head injury (n = 16), and stroke (n = 16). Pediatric intensivists perform the test (n = 13/20). Surveyed participants use TCD ultrasound to decide on treatment and management, start brain death assessment, request brain computed tomography, and manage cerebral perfusion pressure with vasopressors. Conclusion. All surveyed participants use TCD ultrasound findings to guide management or treatments. Half of surveyed participants are little satisfied with their training.

Magnetic resonance angiography and transcranial Doppler ultrasound findings in patients with a clinical diagnosis of vertebrobasilar insufficiency

OBJECTIVE: To evaluate the findings of magnetic resonance angiography (MRA) and transcranial Doppler ultrasound (TCD) in patients with a clinical diagnosis of vertebrobasilar insufficiency (VBI). METHOD: From our outpatient neurotology clinic, we selected patients (using the criteria proposed by Grad and Baloh) with a clinical diagnosis of VBI. We excluded patients with any definite cause for vestibular symptoms, a noncontrolled metabolic disease or any contraindication to MRA or TCD. The patients in the study group were sex- and age-matched with subjects who did not have vestibular symptoms (control group). Our final group of patients included 24 patients (study, n=12; control, n=12). RESULTS: The MRA results did not demonstrate significant differences in the findings between our study and control groups. TCD demonstrated that the systolic pulse velocity of the right middle cerebral artery, end diastolic velocity of the basilar artery, pulsatility index (PI) of the left middle cerebral artery, PI of the right middle cerebral artery, and PI of the basilar artery were significantly higher in the study group than in the control group, suggesting abnormalities affecting the microcirculation of patients with a clinical diagnosis of VBI compared with controls. CONCLUSION: MRA failed to reveal abnormalities in patients with a clinical diagnosis of VBI compared with controls. The PI of the basilar artery, measured using TCD, demonstrated high sensitivity (91%) and specificity (91%) for detecting clinically diagnosed VBI.

Análisis de las lesiones encefálicas en resonancia magnética en pacientes con señales transitorias de alta intensidad detectadas por Doppler transcraneal / Analysis of Encephalic Lesions in Magnetic Resonance Imaging in patients with High Intensity Transient Signals detected on Transcranial Doppler

Resumen Objetivo: Describir los hallazgos en resonancia magnética (RM) de encéfalo en pacientes menores de 65 años que fueron estudiados por Doppler transcraneal (DTC) con contraste de microburbujas, con antecedentes de accidente cerebrovascular (ACV) criptogénico y sospecha de foramen oval permeable (FOP). Materiales y métodos: Este estudio transversal retrospectivo incluyó pacientes de ambos sexos, menores de 65 años. Resultados: Nuestra muestra (n = 47, 47% masculino y 53% femenino, edad media de 42 años) presentó señales transitorias de alta intensidad (HITS, por su sigla en inglés) positivo en el 61,7% y HITS-negativo en el 38,3%. En pacientes HITS-positivo, predominaron las lesiones a nivel de las fibras en U subcorticales, únicas o múltiples con distribución bilateralmente simétrica. En pacientes con HITS moderados, predominaron las lesiones en el territorio vascular de la circulación posterior. Conclusión: En pacientes menores de 65 años con ACV criptogénico y lesiones en fibras en U subcorticales, únicas o múltiples con distribución bilateral y simétrica, debe tenerse en cuenta un FOP como posible causa de dichas lesiones.

Abstract Objectives: To analyze the findings on brain magnetic resonance imaging (MRI) in patients less than 65 years of age with history of cryptogenic stroke and suspected patent foramen ovale (PFO) who were studied with Contrast-Transcranial Doppler. Materials and Methods: This transversal retrospective study included both, men and women less than 65 years of age. Results: Our sample (n = 47, 47% male and 53% female, average age 42 years old) had High Intensity Transient Signals (HITS)-positive in 61.7% and HITS-negative in 38.3%. In HITS-positive patients, lesions were predominantly located on the subcortical U fibers, lone or multiple bilateral symmetric distributions. In patients with moderate-severity HITS, the posterior circulation was the most affected. Conclusion: In patients less than 65 years of age with cryptogenic stroke with lesions affecting the subcortical U fibers, with unique or multiple bilateral symmetric distributions, a PFO should be considered as an underlying cause.

Predictive value of transcranial doppler ultrasound for cerebral small vessel disease in elderly patients / Valor preditivo do ultrassom doppler transcraniano para doença de pequenos vasos em pacientes idosos

ABSTRACT Objective: To investigate the predictive value of transcranial Doppler (TCD) ultrasound for cerebral small vessel disease in elderly patients. Methods: Transcranial Doppler ultrasound and magnetic resonance imaging (MRI) were performed on 184 elderly patients with cerebral small vessel disease. The relationship of clinical characteristics and TCD ultrasound parameters with severe white matter lesions (WMLs) in MRI were investigated by univariate analysis and multivariate analysis. Results: The univariate analysis showed that age, left middle cerebral artery (MCA) mean flow velocity, right MCA mean flow velocity and mean MCA pulsatility index were significantly correlated with severe WMLs (p < 0.05). The multivariate logistic regression analysis showed that only age (odds ratio: 1.21; 95%CI: 1.10-1.36; p < 0.01) and MCA pulsatility index (dominance ratio: 1.13; 95%CI: 1.06-1.80; p = 0.02) were significantly correlated with severe WMLs. The analysis of TCD ultrasound parameters showed that when the cut-off for MCA pulsatility index was 1.04, it could identify severe WMLs. The area under the curve was 0.70 (95%CI: 0.60-0.80). The sensitivity and specificity were 63.0% and 72.0%, respectively. The positive and negative predictive values were 35.4% and 86.6%, respectively. Conclusion: The MCA pulsatility index in TCD ultrasound is significantly correlated with severe WMLs; and TCD ultrasound can guide selective MRI for the detection of WMLs.

RESUMO Objetivo: Investigar o valor preditivo do ultrassom de Doppler transcraniano (TCD) para doença de pequenos vasos (SVD) em pacientes idosos. Métodos: ultrassonografia de TCD e ressonância magnética (RM) foram realizadas em 184 idosos portadores de SVD cerebral. As relações das características clínicas e os parâmetros ultrassonográficos do TCD com lesão grave de substância branca (WML) no desempenho da RM foram investigados por análise univariada e análise multivariada. Resultados: A análise univariada mostrou que, a idade, a velocidade média de fluxo (MFV) da artéria média cerebral (MCA) esquerda, a MFV da MCA direita e o índice de pulsatilidade (PI) médio estiveram significativamente relacionados à WML grave (P <0,05). A análise de regressão logística multivariada mostrou que apenas a idade (razão de chances: 1,21; IC95%: 1,10-1,36; P <0,01) e o PI da MCA (razão de dominância: 1,13; IC 95%: 1,06-1,80; P = 0,02) estiveram significativamente relacionados a WML grave. A análise dos parâmetros ultrassonográficos do TCD mostrou que, quando o ponto de corte do IP do MCA foi 1,04, ele pôde identificar à WML grave. A área sob a curva foi de 0,70 (IC 95%: 0,60-0,80). A sensibilidade e especificidade foram de 63,0% e 72,0%, respectivamente. Os valores preditivos positivos e negativos foram de 35,4% e 86,6%, respectivamente. Conclusão: O PI da MCA na ultrassonografia do TCD está significativamente relacionado à WML grave. A ultrassonografia TCD pode orientar a ressonância magnética seletiva para detecção da WML.

Research progress in ultrasound use for the diagnosis and treatment of cerebrovascular diseases

Cerebrovascular diseases pose a serious threat to human survival and quality of life and represent a major cause of human death and disability. Recently, the incidence of cerebrovascular diseases has increased yearly. Rapid and accurate diagnosis and evaluation of cerebrovascular diseases are of great importance to reduce the incidence, morbidity and mortality of cerebrovascular diseases. With the rapid development of medical ultrasound, the clinical relationship between ultrasound imaging technology and the diagnosis and treatment of cerebrovascular diseases has become increasingly close. Ultrasound techniques such as transcranial acoustic angiography, doppler energy imaging, three-dimensional craniocerebral imaging and ultrasound thrombolysis are novel and valuable techniques in the study of cerebrovascular diseases. In this review, we introduce some of the new ultrasound techniques from both published studies and ongoing trials that have been confirmed to be convenient and effective methods. However, additional evidence from future studies will be required before some of these techniques can be widely applied or recommended as alternatives.

Ultrasonido doppler transcraneal en la prevención del accidente vascular encefálico en niños con drepanocitosis / Transcranial doppler ultrasound in the prevention of cerebrovascular accident in children with sickle cell disease

Introducción: las complicaciones neurológicas y sus secuelas se conocen casi desde la primera descripción de la depranocitosis y son más frecuentes en la anemia drepanocítica. Varían con la edad; pueden ser agudas o crónicas y producen una elevada morbimortalidad. Objetivo: conocer la frecuencia de niños con AD que tienen alteraciones en la velocidad del flujo sanguíneo cerebral, relacionar estas alteraciones con los eventos clínicos y los datos de laboratorio y evaluar la evolución en el tiempo de los pacientes con alteraciones y su asociación con el uso de hidroxiurea. Métodos: se realizó un estudio prospectivo analítico que incluyó a 50 pacientes con anemia drepanocítica con edades comprendidas entre 5 y 18 años, atendidos en el Instituto de Hematología e Inmunología. Se determinaron las alteraciones del flujo sanguíneo cerebral (FSC) y su asociación con otros elementos clínicos y hematológicos. Resultados: las arterias que mayor velocidad del FSC mostraron fueron la arteria cerebral media derecha (121,6 cm/s) y la izquierda (115 cm/s). Las alteraciones de la velocidad del FSC en el ultrasonido doppler transcraneal (UDTC) fueron: 11 (22 por ciento) pacientes con velocidades mayores de 170 cm/s, 6 (12 por ciento) con un flujo entre 170 ­ 199 cm/s, y 5 (10 por ciento) mayor de 200 cm/s. Existió una correlación inversa entre la velocidad del FSC con la edad y las cifras de hemoglobina, y directa con la cifra de plaquetas. El accidente vascular encefálico, las transfusiones y las hospitalizaciones fueron los eventos clínicos más frecuentes en los pacientes con UDTC anormal. Las velocidades del FSC disminuyeron significativamente (31 cm/s; p = 0,034) en los pacientes que recibieron tratamiento con hidroxiurea. Conclusiones: la detección de alteraciones en el UDTC permite detectar el riesgo de AVE y adoptar las medidas oportunas de prevención del AVE(AU)

Introduction: neurological complications and their sequelae are known almost since the first description of sickle cell disease, most commonly in sickle cell anemia. They vary with age, can be acute or chronic and produce high morbidity and mortality. Aims: to determine the frequency of children with AD who have alterations in cerebral blood flow velocity, relate these changes to clinical events and laboratory data and assess the evolution over time of patients with abnormalities and their association with the use of hydroxyurea. Methods: a prospective analytical study involving 50 patients with sickle cell disease, aged 5 to 18, was performed in at the Institute of Hematology and Immunology where they are assisted. Alterations in cerebral blood flow (CBF) and the association with other clinical and hematological elements were determined. Results: the arteries that showed larger speed were right middle cerebral artery (121.6 cm/s) and left (115 cm/s). Patients with impaired CBF velocity in transcranial Doppler ultrasound were 11 ( 22 percent) with speeds greater higher than 170 cm/s , 6 patients (12 percent) with a flow between 170-199 cm/s, and five (10 percent) greater higher than 200 cm / s. There was an inverse correlation between CBF velocity with age and hemoglobin levels and directly with the platelet count. The cerebrovascular accident, blood transfusions and hospitalizations were the most frequent clinical events in patients with abnormal transcranial doppler ultrasound. FSC velocities were significantly decreased (31 cm /s; p = 0,034) in patients receiving treatment with hydroxyurea. Conclusions: Patients with alterations in the transcranial Doppler ultrasound must be included in a program for primary prevention of cerebrovascular accident(AU)

Momento quirúrgico apoyado con doppler transcraneal en pacientes con hemorragia subaracnoidea aneurismática / Surgical timing supported by transcranial doppler in patients with subarachnoid hemorrhage from aneurisms rupture

Introducción: La cirugía de la hemorragia subaracnoidea aneurismática (HSA) realizada en las primeras 72 horas es beneficiosa. Cuando los casos arriban transcurrido este período el mejor momento quirúrgico es controversial. Objetivo. Evaluar la influencia sobre los resultados de la cirugía en la HSA de un protocolo para decidir el momento quirúrgico apoyado en el monitoreo con Doppler transcraneal (DTC). Material y Método: Se comparan los resultados quirúrgicos al alta y al año de seguimiento según la escala de Glasgow para resultados (EGR), en una serie de 233 casos con HSA rotos operados Enero de 2006 - Diciembre de 2010 y seguidos hasta Enero de 2012, en los que la cirugía en el período intermedio se decidió teniendo en cuenta las velocidades de flujo de los segmentos proximales del polígono de Willis registradas por DTC, con los de un grupo control histórico operado Diciembre de 1983 - Diciembre de 2005 sin la ayuda de dicho monitoreo. Resultados: La mortalidad al alta y al año en la serie de estudio fue de 4,3 y 4,5 por ciento y en el grupo control 7 y 7,7 por ciento respectivamente. Se observaron resultados satisfactorios (grados 4 y 5 en EGR) en el 93,1 al alta y 92,8 por ciento al año en la serie de estudio. Entre los controles históricos estos índices fueron 85,6 y 88,1 por ciento respectivamente (p = 0,004 y p = 0,036). Conclusiones: Los resultados del tratamiento microquirúrgico de la HSA se benefician con la atención protocolizada y la consideración de los resultados del DTC para seleccionar el momento quirúrgico.

Background: Aneurysmal subarachnoid hemorrhage (SAH) surgery, practiced in the first 72 hours is beneficial. The optimal surgical timing, for microsurgical clipping of ruptured intracranial aneurysms, remains controversial when patients arrive between 4 and 14 days. Some surgeons favor a prompt operation regardless the timing. Other ones prefer to wait 2 weeks. Most patients in developing countries are taken to neurosurgical attention late, which not permit an early surgery. Object. To evaluate the surgical outcome in a series of patients with subarachnoid hemorrhage (SAH) managed according to a dynamic protocol. Methods: The authors evaluated surgical outcome by means of Glasgow Outcome Scale (GOS) score in a series of 233 patients with SAH who received neurosurgical clipping in the years 2006-2010 and were followed until January 2012, whose surgical timing was decided according to transcranial Doppler (TD) monitoring. These outcomes were compared with results in a series of 445 historic controls operated 1983-2005. Results: Series mortality at the discharge and at the year were 4.3 and 4.5 percent, and 7 and 7.7 percent in the control group respectively. Series show good outcomes (grade 4 and grade 5 in GOS score) in 93.1 at the discharge and 92.8 percent at the year. Among the historic controls cases with good outcome were 85.6 and 88.1 percent respectively (p = 0.004 y p = 0.036). Conclusions: Surgical outcomes of SAH can be favored by the impact of protocolized attention and TD to decide the best surgical timing in SAH.

Consenso Latinoamericano sobre el uso del Doppler transcraneal en el diagnóstico de muerte encefálica / Latin American consensus on the use of transcranial Doppler in the diagnosis of brain death

El Doppler transcraneal evalúa la hemodinámica cerebral en el paciente neurocrítico. Se destaca su aporte como técnica auxiliar en el diagnóstico del paro circulatorio cerebral, que habitualmente presenta el paciente en muerte encefálica. Este Consenso Latinoamericano se conformó por un grupo de 26 médicos con experiencia en el uso de Doppler transcraneal en el contexto de muerte encefálica. El propósito de este consenso es realizar recomendaciones en relación a las indicaciones, técnica e interpretación del estudio de la ultrasonografía transcraneal en el paciente con diagnóstico clínico de muerte encefálica o en aquel paciente cuyo diagnóstico clínico presenta dificultades; formar un grupo de trabajo que permita profundizar conocimientos y consolidar lazos entre médicos latinoamericanos trabajando en el mismo tema. Se revisó la literatura, se intercambiaron conceptos y experiencias en dos encuentros presenciales y vía Internet. Se contestaron preguntas sobre fisiopatología, equipo, técnica, hallazgos, problemas frecuentes e interpretación del Doppler transcraneal en el contexto de muerte encefálica. Las declaraciones fundamentales del consenso son: El paro circulatorio cerebral es la última etapa en la evolución de la hipertensión intracraneana progresiva, donde se visualiza con el Doppler transcraneal un "patrón de paro circulatorio cerebral". Se acepta como patrón de paro circulatorio cerebral: patrón reverberante, espigas sistólicas y ausencia de flujo previamente evidenciado. Se debe insonar - en condiciones hemodinámicas aceptables - sector anterior bilateralmente (arterias cerebrales medias) y sector posterior (arteria basilar). De no encontrarse ninguna imagen ultrasonográfica en éstas, las arterias proximales (carótida interna ipsilateral en sifón o ambas vertebrales respectivamente) son aceptables para el diagnóstico de paro circulatorio cerebral.

Transcranial Doppler evaluates cerebral hemodynamics in patients with brain injury and is a useful technical tool in diagnosing cerebral circulatory arrest, usually present in the brain-dead patient. This Latin American Consensus was formed by a group of 26 physicians experienced in the use of transcranial Doppler in the context of brain death. The purpose of this agreement was to make recommendations regarding the indications, technique, and interpretation of the study of transcranial ultrasonography in patients with a clinical diagnosis of brain death or in the patient whose clinical diagnosis presents difficulties; a working group was formed to enable further knowledge and to strengthen ties between Latin American physicians working on the same topic. A review of the literature, concepts, and experiences were exchanged in two meetings and via the Internet. Questions about pathophysiology, equipment, techniques, findings, common problems, and the interpretation of transcranial Doppler in the context of brain death were answered. The basic consensus statements are the following: cerebral circulatory arrest is the final stage in the evolution of progressive intracranial hypertension, which is visualized with transcranial Doppler as a "pattern of cerebral circulatory arrest". The following are accepted as the standard of cerebral circulatory arrest: reverberant pattern, systolic spikes, and absence of previously demonstrated flow. Ultrasonography should be used - in acceptable hemodynamic conditions - in the anterior circulation bilaterally (middle cerebral artery) and in the posterior (basilar artery) territory. If no ultrasonographic images are found in any or all of these vessels, their proximal arteries are acceptable to be studied to look for a a pattern of cerebral circulatory arrest.

Síndrome del robo de la subclavia / Syndrome of subclavian steal

Paciente femenina de 46 años de edad, con antecedentes de hipertensión arterial y fumadora habitual. Desde hace 2 años presenta episodios aislados y breves de vértigos, inestabilidad postural, sensación de desfallecimiento sin alteraciones de la conciencia, después de realizar ejercicios del brazo izquierdo. El examen neurológico muestra asimetría de pulsos carotídeos y radiales. El doppler extracraneal reveló alteraciones ateroscleróticas en ambos ejes carotídeos, con estenosis derecha del 50 %, disminución del flujo de la arteria vertebral izquierda y obstrucción proximal de la arteria subclavia izquierda proximalmente. El síndrome del robo de la subclavia es una entidad poco frecuente, su diagnóstico es clínico y se demuestra mediante doppler o angiografía. El tratamiento debe ser decidido individualmente en cada caso.

A 46 year-old female patient with a history of hypertension and regular smoker complained of isolated and brief episodes of dizziness, postural instability, faint feeling without altered consciousness, after exercise the left arm for 2 years. Her neurological examination showed asymmetry of carotid and radial pulses. Her extracranial doppler revealed carotid atherosclerotic changes in both axes, with 50 % right stenosis, decreased flow of the proximal left vertebral artery and obstruction of the proximal left subclavian artery. Subclavian Steal Syndrome is a rare condition. Its diagnosis is clinical and it is demonstrated by Doppler or angiography. Treatment should be determined individually in each case.

Right-to-left shunt and the hypercoagulable state: does paradoxical embolism play a role in patients with antiphospholipid syndrome and stroke? / Shunt direita-esquerda e hipercoagulabilidade: embolia paradoxal pode ser responsável pelo AVC na síndrome antifosfolipídica?

OBJECTIVE: Patent foramen ovale is associated with paradoxical embolism (PE) and stroke. Hypercoagulable states, such as antiphospholipid syndrome (APS), can exacerbate PE by increasing clot formation. The aim of this study was to verify whether patients with APS and stroke present a right-to-left shunt (RLS) with greater frequency than patients with APS but without stroke. METHODS: Fifty-three patients with APS were tested for RLS using contrast-enhanced transcranial Doppler (cTCD): 23 patients had a history of stroke (Stroke Group) and 30 had no history of stroke (No-stroke Group). RESULTS: cTCD was positive in 15 patients (65%) from the Stroke Group and in 16 patients (53%) in the No-stroke Group (p=0.56). The proportion of patients with a small RLS (<10 high-intensity transient sign or HITS) and a large RLS (>10 HITS) was similar between the groups without significant difference. CONCLUSIONS: Our data do not support the theory that paradoxical embolism may play an important role in stroke in APS patients.

OBJETIVO: O forame oval patente está associado com embolia paradoxal e acidente vascular cerebral isquêmico (AVCi). Estados de hipercoagulabilidade, como a síndrome antifosfolipídica (SAF), podem facilitar esse processo, aumentando a formação de coágulos. O objetivo deste estudo foi verificar se pacientes com SAF e AVCi apresentam maior frequência de shunt direita-esquerda (SDE), comparados a pacientes com SAF sem AVCi. MÉTODOS: Cinquenta e três pacientes com SAF foram testados para SDE usando Doppler transcraniano contrastado (DTCc): 23 com AVCi (Grupo AVC) e 30 sem história de AVCi (Grupo Controle). RESULTADOS: DTCc foi positivo em 15 pacientes (65%) do Grupo AVC e em 16 pacientes (53%) no Grupo Controle (p=0,56). A proporção de pacientes com pequeno SDE (<10 HITS) e grande SDE (>10 HITS) foi semelhante nos dois grupos. Não houve diferença significativa entre os grupos. CONCLUSÕES: Nossos dados não sugerem que embolia paradoxal seja causa importante de AVCi em pacientes com SAF.

Riesgo de ictus isquémico en niños con Sβ talasemia. Estudio con Doppler transcraneal / Risks of ischemic stroke in children suffering S-thalassemia. Transcranial Doppler study

En niños con anemia por células falciformes, el riesgo de ictus isquémico varía según el genotipo de la hemoglobinopatía. En estos casos, la determinación de la velocidad de flujo sanguíneo mediante Doppler transcraneal (DTC) puede predecir la ocurrencia de isquemia cerebral. Con el objetivo de describir las características del DTC en la Sβ talasemia, se estudiaron 32 enfermos menores de 18 años atendidos en el Instituto de Hematología e Inmunología y remitidos para su evaluación con ultrasonido. La edad media de los niños fue de 10,5 años. Se estudió la misma cantidad de enfermos con cada genotipo Sβ; solamente en un paciente la ventana temporal no fue útil. En el 97 % de los enfermos la velocidad media de flujo en las arterias cerebrales medias era inferior a 170 cm/s y solo en un niño estaban en el rango del grupo condicional. Se registraron asimetrías interhemisféricas en la velocidad media de flujo de las arterias cerebrales anteriores en el 29 por ciento de los casos; en el 19,6 por ciento en las arterias cerebrales medias; y en el 6,4 por ciento en las carótidas internas extracraneales. Los niveles más altos de velocidad media de flujo se registraron en los enfermos con Sβ0 talasemia y en las arterias cerebrales medias. Existió una correlación inversa entre la edad y los niveles de hemoglobina con la velocidad de flujo de los 3 vasos estudiados. El riesgo de ictus isquémico en la Sβ talasemia es bajo, sin diferencia entre los 2 genotipos evaluados

In children with sickle cell anemia, the risk of ischemic stroke varies according to genotype of hemoglobinopathy. In these cases, determining the velocity of blood flow by transcranial Doppler (TCD) can predict the occurrence of cerebral ischemia. In order to describe the characteristics of DTC in Sβ thalassemia, we studied 32 patients younger than 18 treated at the Institute of Hematology and Immunology, who were referred for ultrasound assessment. The age rate of children was 10.5 years old. We studied the same number of patients with each genotype Sβ, in only one patient the time window was not useful. 97 percent of patients the mean flow velocity in the middle cerebral arteries was less than 170 cm/s and only one child was in the range of conditional group. Interhemispheric asymmetries were registered in the average flow rate of the anterior cerebral arteries in 29 percent cases, 19.6 percent registered it in the middle cerebral arteries, and 6.4 percent in the extracranial internal carotid. The highest levels of average flow rate were registered in patients with thalassemia Sβ0 and middle cerebral arteries. There was an inverse correlation between age and hemoglobin levels with the flow rate of three studied vessels. The risk of ischemic stroke in the Sβ thalassemia is low, with no difference between the two assessed genotypes

Brazilian guidelines for the application of transcranial ultrasound as a diagnostic test for the confirmation of brain death / Diretrizes brasileiras para o uso do ultrassom transcraniano como teste diagnóstico de confirmação de morte cerebral

Neurosonological studies, specifically transcranial Doppler (TCD) and transcranial color-coded duplex (TCCD), have high level of specificity and sensitivity and they are used as complementary tests for the diagnosis of brain death (BD). A group of experts, from the Neurosonology Department of the Brazilian Academy of Neurology, created a task force to determine the criteria for the following aspects of diagnosing BD in Brazil: the reliability of TCD methodology; the reliability of TCCD methodology; neurosonology training and skills; the diagnosis of encephalic circulatory arrest; and exam documentation for BD. The results of this meeting are presented in the current paper.

Estudos neurossonológicos, especialmente o Doppler transcraniano (DTC) e o duplex transcraniano codificado a cores (DTCC), apresentam elevados níveis de especificidade e sensibilidade quando utilizados como exames complementares no diagnóstico de morte encefálica (ME). Um grupo de peritos do Departamento Científico de Doppler transcraniano da Academia Brasileira de Neurologia criou uma força-tarefa de forma a determinar os critérios neurossonológicos para os seguintes aspectos no diagnóstico de ME no Brasil: metodologia do DTC; metodologia do DTCC; treinamento e habilidades em Neurossonologia; diagnóstico de parada circulatória encefálica e documentação do exame para a ME. Os resultados deste encontro foram apresentados neste artigo.

A ultrassonografia transcraniana como método diagnóstico em neurologia. Parte II: revisão da literatura / Transcranial Ultrasonography as diagnostic method in neurology. Part II: Literature review

A ultrassonografia transcraniana (USTC) é um método de neuroimagem baseado na física acústica. Nos indivíduos com janela acústica temporal adequada, o exame permite a visualização de estruturas encefálicas, principalmente o mesencéfalo, núcleos da base, tálamos e segmentos do sistema ventricular. A técnica já foi utilizada em pesquisas de diversas doenças neuropsiquiátricas. Em cerca de 90% dos portadores da doença de Parkinson, observa-se um aumento da área ecogênica da substância negra visualizada à USTC. O presente artigo é a segunda parte de uma revisão bibliográfica sobre o tema.

Transcranial sonography (TCS) is a neuroimaging technique that uses physical acoustic principles. A good acoustic temporal bone window allows sonographic depiction of encephalic structures as the mesencephalon, basal ganglia, thalami and fragments of the ventricular system. The technique has been used in researches of different neuropsychiatric diseases. In 90% of Parkinsonïs disease patients an enlargement of the substantia nigra echogenic area is found by TCS. This paper is a review on the subject.

Results from transcranial Doppler examination on children and adolescents with sickle cell disease and correlation between the time-averaged maximum mean velocity and hematological characteristics: a cross-sectional analytical study / Resultados do estudo do Doppler transcraniano em crianças e adolescentes portadores de doença falciforme e correlação entre a velocidade média máxima e características hematológicas: um estudo transversal analítico

CONTEXT AND OBJECTIVE: Transcranial Doppler (TCD) detects stroke risk among children with sickle cell anemia (SCA). Our aim was to evaluate TCD findings in patients with different sickle cell disease (SCD) genotypes and correlate the time-averaged maximum mean (TAMM) velocity with hematological characteristics. DESIGN AND SETTING: Cross-sectional analytical study in the Pediatric Hematology sector, Universidade Federal de São Paulo. METHODS: 85 SCD patients of both sexes, aged 2-18 years, were evaluated, divided into: group I (62 patients with SCA/Sß0 thalassemia); and group II (23 patients with SC hemoglobinopathy/Sß+ thalassemia). TCD was performed and reviewed by a single investigator using Doppler ultrasonography with a 2 MHz transducer, in accordance with the Stroke Prevention Trial in Sickle Cell Anemia (STOP) protocol. The hematological parameters evaluated were: hematocrit, hemoglobin, reticulocytes, leukocytes, platelets and fetal hemoglobin. Univariate analysis was performed and Pearson's coefficient was calculated for hematological parameters and TAMM velocities (P < 0.05). RESULTS: TAMM velocities were 137 ± 28 and 103 ± 19 cm/s in groups I and II, respectively, and correlated negatively with hematocrit and hemoglobin in group I. There was one abnormal result (1.6 percent) and five conditional results (8.1 percent) in group I. All results were normal in group II. Middle cerebral arteries were the only vessels affected. CONCLUSION: There was a low prevalence of abnormal Doppler results in patients with sickle-cell disease. Time-average maximum mean velocity was significantly different between the genotypes and correlated with hematological characteristics.

CONTEXTO E OBJETIVO: Doppler transcraniano (DTC) detecta risco de acidente vascular cerebral (AVC) em crianças com anemia falciforme (AF). O objetivo foi avaliar os resultados ao DTC nos diferentes genótipos da doença falciforme (DF) e correlacionar a velocidade média-máxima (VMMáx) às características hematológicas. TIPO DE ESTUDO E LOCAL: Estudo transversal analítico realizado no setor de Hematopediatria da Universidade Federal de São Paulo. MÉTODOS: 85 pacientes com DF, 2-18 anos, ambos os sexos, foram avaliados e divididos em: grupo I (62 com AF ou Sß0 talassemia); e grupo II (23 com hemoglobinopatia SC ou Sß+ talassemia). DTC foi realizado e revisado por um único investigador usando um aparelho de ultrassonografia Doppler com transdutor de 2MHz, conforme critérios do protocolo STOP (Stroke Prevention Trial in Sickle Cell Anemia). As variáveis hematológicas avaliadas foram: hematócrito, hemoglobina, reticulócitos, leucócitos, plaquetas, hemoglobina fetal. Análise univariada e coeficiente de Pearson calculados para parâmetros hematológicos e VMMáx, P < 0,05. RESULTADOS: As média das VMMáx foram de 137 ± 28 cm/s e 103 ± 19 cm/s nos grupos I e II, respectivamente. Houve correlação negativa da VMMáx com hematócrito e hemoglobina no grupo I. Houve um (1,6 por cento) resultado anormal e 5 (8,1 por cento) condicionais no grupo I; no grupo II, todos estavam normais. Artérias cerebrais médias foram as únicas acometidas. CONCLUSÃO: Houve baixa prevalência de resultados anormais ao DTC em pacientes com DF. A VMMáx foi significativamente diferente entre os genótipos da DF e apresentou correlação com variáveis hematológicas.

A ultrassonografia transcraniana como método diagnóstico em neurologia. Parte I: Princípios e metodologia / Transcranial ultrasonography as a diagnostic method in neurology. Part I: Principles and methodology

A ultrassonografia transcraniana (USTC) é uma promissora técnica de neuroimagem para a investigação de distúrbios do movimento. O exame tem baixo custo, é inócuo, não é invasivo e pode ser realizado nos pacientes com movimentos involuntários sem sedação. As suas limitações incluem dependência de janela óssea adequada e de experiência e qualificação do examinador. Os valores de referência, no momento, só existem para pacientes da Europa, Estados Unidos da América e Ásia. A primeira parte do artigo apresenta alguns aspectos da técnica do exame; a segunda parte faz uma revisão da bibliografia disponível sobre a utilização da USTC em doenças neurológicas, particularmente na doença de Parkinson.

Transcranial sonography (TCS) is a promising neuroimaging technique for investigating movement disorders. The exam is inexpensive, harmless, non-invasive, and quick to perform in moving patients. Its limitations include its dependency on an adequate bone window and on qualified personnel. Reference values only exist for patients from Europe, North America and Asia. In the first part of this paper we present some technical aspects of the exam; the second part reviews the bibliography about TCS in neurological diseases, Parkinson's disease above all.

Brazilian Guidelines for transcranial doppler in children and adolescents with sickle cell disease

BACKGROUND: Sickle cell disease is the most common monogenic hereditary disease in Brazil. Although strokes are one of the main causes of morbidity and mortality in these patients, the use of transcranial Doppler to identify children at risk is not universally used. OBJECTIVE: To develop Brazilian guidelines for the use of transcranial Doppler in sickle cell disease children and adolescents, so that related health policies can be expanded, and thus contribute to reduce morbidity and mortality. METHODS: The guidelines were formulated in a consensus meeting of experts in transcranial Doppler and sickle cell disease. The issues discussed were previously formulated and scientific articles in databases (MEDLINE, SciELO and Cochrane) were carefully analyzed. The consensus for each question was obtained by a vote of experts on the specific theme. RESULTS: Recommendations were made, including indications for the use of transcranial Doppler according to the sickle cell disease genotype and patients age; the necessary conditions to perform the exam and its periodicity depending on exam results; the criteria for the indication of blood transfusions and iron chelation therapy; the indication of hydroxyurea; and the therapeutic approach in cases of conditional transcranial Doppler. CONCLUSION: The Brazilian guidelines on the use of transcranial doppler in sickle cell disease patients may reduce the risk of strokes, and thus reduce the morbidity and mortality and improve the quality of life of sickle cell disease patients.

Estudio de correlación clínico-radiológica, sensibilidad y especificidad de ecotomografía transcraneana en enfermedad de Parkinson y otros trastornos del movimiento / Transcranial sonography for the diagnosis of Parkinson disease

Background: The detection of hyperechogenicity of the substantia nigra using trans cranial sonography can bepredictive ofthe diagnosis of Parkinson Disease. Aim: To report an experience with transcranial sonography for the diagnosis of Parkinson disease. Material ana Methods: One hundred sixteen patients with movement disorders were subjected to a transcranial sonograpy to detect the presence ofhyper-chogenicity of the substantia nigra and basal ganglia. Afterwards, two physicians, unaware ofthe results ofthe sonography, examined the patients and reached a clinical diagnosis. The concordance between ultrasound results and the clinical diagnosis was analyzed. Results: In 64 patients, a clinical diagnosis of Parkinson disease was reached. Ofthese, 52 patients had substantia nigra hyperechogenicity and in 12, it was normal. On the other hand ultrasound was normal in 42 of43 patients without a clinical diagnosis of Parkinson disease. Therefore the sensitivity and specificity of trans cranial ultrasound for the diagnosis of Parkinson disease was 81 and 97 percent, res-pectively. Conclusions: Transcranial sonography has agood sensitivity and specificity for the diagnosis of Parkinson disease.