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.

Genetic, laboratory and clinical risk factors in the development of overt ischemic stroke in children with sickle cell disease

ABSTRACT Cerebrovascular disease, particularly stroke, is one of the most severe clinical complications associated with sickle cell disease and is a significant cause of morbidity in both children and adults. Over the past two decades, considerable advances have been made in the understanding of its natural history and enabled early identification and treatment of children at the highest risk. Transcranial Doppler screening and regular blood transfusions have markedly reduced the risk of stroke in children. However, transcranial Doppler has a limited positive predictive value and the pathophysiology of cerebrovascular disease is not completely understood. In this review, we will focus on the current state of knowledge about risk factors associated with ischemic stroke in patients with sickle cell disease. A search of PubMed was performed to identify studies. Full texts of the included articles were reviewed and data were summarized in a table. The coinheritance of alpha-thalassemia plays a protective role against ischemic stroke. The influence of other genetic risk factors is controversial, still preliminary, and requires confirmatory studies. Recent advances have established the reticulocyte count as the most important laboratory risk factor. Clinical features associated with acute hypoxemia as well as silent infarcts seem to influence the development of strokes in children. However, transcranial Doppler remains the only available clinical prognostic tool to have been validated. If our understanding of the many risk factors associated with stroke advances further, it may be possible to develop useful tools to detect patients at the highest risk early, improving the selection of children requiring intensification therapy.

Clinical study of monitoring of transcranial Doppler ultrasonography to seriously illed children with cerebral dysfunction / 中国小儿急救医学

Objective To investigate the application value of transcranial Doppler ultrasonography(TCD) in critically ill children with cerebral dysfunction.Methods We detected the cerebral blood flow parameters[systolic velocity(Vs),mean velocity(Vm),end of diastolic velocity(Vd),pulsatility index(PI),resistance index(RI)] of middle cerebral artery in cerebral dysfunction group(n=20) and control group(no cerebral dysfunction,n=20),and observed the differences of those parameters between two groups.Children in cerebral dysfunction group were also divided into groups according to Glasgow Coma Score(GCS) and prognosis.The differences of each TCD parameter in diverse groups divided by GCS and by prognosis were analysed.Children in cerebral dysfunction group were checked TCD everyday until TCD parameters were normal.The relation between the days of TCD parameters′ reaching normal and GCS,duration of disorder of consciousness with correlation analysis were analysed.Results Vs,PI,RI in cerebral dysfunction group were higher than those in control group,while Vd was lower (P<0.05).(2)PI in the group of GCS less than 6 points(0.91±0.21) was higher than that in group of GCS 7-13 points(0.83±0.14)(P<0.05).The other parameters between two groups of GCS less than 6 points and GCS 7-13 points were not significantly indistinctive.Between the good prognosis group and the bad prognosis group,there were no significant differences in all parameters.(3) The days of TCD parameters′ reaching normal were negatively correlated with GCS(r=-0.653,P<0.01),but positively correlated with the duration of disorder of consciousness(r=0.923,P<0.01).Conclusion The cerebral hemodynamics of children with cerebral dysfunction is abnormal,the more serious cerebral dysfunction,the higher PI and the longer time for regaining normal TCD parameters.Constantly monitoring TCD could reflect the changes of cerebral hemodynamics and is valuable to assess the state of illness and prognosis.

Cerebral monitoring during carotid endarterectomy by transcranial Doppler ultrasonography

PURPOSE: To evaluate the efficacy and safety of cerebral monitoring by transcranial Doppler ultrasonography (TCD) for the detection of cerebral ischemia during carotid endarterectomy (CEA). METHODS: From August 2004 to December 2013, 159 CEAs were performed in a tertiary hospital. All procedures were performed under general anesthesia. Intraoperative TCD was routinely used to detect cerebral ischemia. Of the 159 patients, 102 patients were included in this study, excluding 27 patients who had a poor transtemporal isonation window and 30 patients who used additional cerebral monitoring systems such as electroencephalography or somatosensory evoked potentials. When mean flow velocity in the ipsilateral middle cerebral artery decreased by >50% versus baseline during carotid clamping carotid shunting was selectively performed. The carotid shunt rate and incidence of perioperative (<30 days) stroke or death were investigated by reviewing medical records. RESULTS: Carotid shunting was performed in 31 of the 102 patients (30%). Perioperative stroke occurred in 2 patients (2%); a minor ischemic stroke caused by embolism in one and an intracerebral hemorrhage in the other. Perioperative death developed in the latter patient. CONCLUSION: TCD is a safe cerebral monitoring tool to detect cerebral ischemia during CEA. It can reduce use of carotid shunt.

A comparative analysis of transcranial Doppler parameters acquired during carotid stenting and semi-eversion carotid endarterectomy / Uma análise comparativa de parâmetros do Doppler transcraniano adquiridos durante a colocação de stent carotídeo e endarterectomia carotídea por semieversão

Abstract Background Carotid endarterectomy (CEA) and carotid artery stenting (CAS) have both been proposed for treatment of critical atherosclerotic stenosis located at the carotid bifurcation. Monitoring of hyperintense microembolic signals (MES) by transcranial Doppler ultrasound (TCD) is considered a method of quality control, both in CEA and in CAS. Objective To analyze temporal distribution of MES throughout both semi-eversion CEA and CAS procedures and to evaluate changes in mean velocity of blood flow through the ipsilateral middle cerebral artery (MCA). Method Thirty-three procedures (17 CEA and 16 CAS) were prospectively monitored using TCD and the data were related to three different stages of surgery (pre-cerebral protection, during cerebral protection and post-cerebral protection). Chi-square, Mann-Whitney, ANOVA and contrast tests were used for statistical analysis. Results The MES were uniformly distributed in the CEA group, but not in the CAS group (p = 0.208). The number of MES was higher in the CAS group in all stages. The average flow in the MCA was similarly lower in both groups during the protection stage. Conclusion CEA provoked a lower incidence of MES per procedure than CAS in all stages. The behavior of the averages of the mean of blood flow through the MCA was similar in both groups.

Resumo Contexto A endarterectomia carotídea (EC) e a angioplastia carotídea (AC) são propostas para o tratamento de estenoses críticas localizadas na bifurcação carotídea. O monitoramento dos sinais de microembolias (SMs) pela ultrassonografia Doppler transcraniana (UDT) é considerado um método de controle de qualidade para ambas as técnicas. Objetivos Analisar a distribuição temporal dos SMs ao longo de diferentes estágios da EC por semieversão e da AC, e avaliar o significado das mudanças nas médias das velocidades médias do fluxo na artéria cerebral média ipsilateral (ACM). Método Trinta e três procedimentos (17 ECs e 16 ACs) foram monitorados com UDT, e os dados foram coletados prospectivamente para diferenciar os diferentes estágios cirúrgicos (pré, durante e pós-proteção cerebral). Para análise estatística foram usados os testes qui-quadrado, Mann-Whitney, análise de variância (ANOVA) e contraste. Resultados Em ambos os grupos, os SMs foram distribuídos uniformemente (p = 0,208). Em todos os tempos, o número de SMs foi superior no grupo AC. A média das velocidades médias do fluxo na ACM foi menor durante o tempo de proteção em ambos os grupos. Conclusão A EC teve uma menor incidência de SMs que a AC em todos os estágios. A média das velocidades médias na ACM teve comportamento similar em ambos os grupos.

Cerebral blood flow assessment of preterm infants during respiratory therapy with the expiratory flow increase technique / Avaliação do fluxo sanguíneo cerebral de recém-nascidos prematuros durante a fisioterapia respiratória com a técnica do aumento do fluxo expiratório

Objective: To assess the impact of respiratory therapy with the expiratory flow increase technique on cerebral hemodynamics of premature newborns. Methods: This is an intervention study, which included 40 preterm infants (≤34 weeks) aged 8-15 days of life, clinically stable in ambient air or oxygen catheter use. Children with heart defects, diagnosis of brain lesion and/or those using vasoactive drugs were excluded. Ultrasonographic assessments with transcranial Doppler flowmetry were performed before, during and after the increase in expiratory flow session, which lasted 5min. Cerebral blood flow velocity and resistance and pulsatility indices in the pericallosal artery were assessed. Results: Respiratory physical therapy did not significantly alter flow velocity at the systolic peak (p=0.50), the end diastolic flow velocity (p=0.17), the mean flow velocity (p=0.07), the resistance index (p=0.41) and the pulsatility index (p=0.67) over time. Conclusions: The expiratory flow increase technique did not affect cerebral blood flow in clinically-stable preterm infants.

Objetivo: Avaliar a repercussão da fisioterapia respiratória com a técnica de aumento do fluxo expiratório sobre a hemodinâmica cerebral de recém-nascidos prematuros. Métodos: Estudo de intervenção no qual foram incluídos 40 neonatos prematuros (≤34 semanas) com 8-15 dias de vida, clinicamente estáveis em ar ambiente ou em uso de cateter de oxigênio. Foram excluídas crianças com malformações cardíacas, diagnóstico de lesão cerebral e/ou em uso de drogas vasoativas. Exames de ultrassonografia com avaliação por dopplerfluxometria cerebral foram feitos antes, durante e depois da sessão de aumento do fluxo expiratório, que durou cinco minutos. Foram avaliadas as velocidades de fluxo sanguíneo cerebral e os índices de resistência e pulsatilidade na artéria pericalosa. Resultados: A fisioterapia respiratória não alterou significativamente a velocidade de fluxo no pico sistólico (p=0,50), a velocidade de fluxo diastólico final (p=0,17), a velocidade média de fluxo (p=0,07), o índice de resistência (p=0,41) e o índice de pulsatilidade (p=0,67) ao longo do tempo. Conclusões: A manobra de aumento do fluxo expiratório não afetou o fluxo sanguíneo cerebral em recém-nascidos prematuros clinicamente estáveis.

The role of microembolic signal monitoring in brainstem infarction and vertebrobasilar artery stenosis / 天津医药

Objective To investigate the relation between microembolic signals (MES) and vertebral basilar artery ste?nosis in patients with brainstem infarction. Methods A total of 156 patients with acute brainstem infarction, who were de?termined the cerebral infarction lesion and vertebral basilar artery stenosis by cranial magnetic resonance imaging and CT an?giography, and were monitored by transcranial Doppler via occipital window of basilar arterial MES monitoring in 7 days of the onset, were divided into microembolus signal negative group (n=136) and positive group (n=20). The clinical data were compared between two groups. The differences of different degrees of stenosis were analyzed in two groups. The differences of different locations of stenosis in patients with vertebral basilar artery stenosis were analyzed in two groups. Logistic regres?sion analysis was used to analyse the factors affecting MES. Results There were no significant differences in age, gender, history of hypertension and diabetes mellitus between the two groups (P<0.05). There were significant differences in the dif?ferent degrees of stenosis between two groups, no or mild stenosis was found in MES-negative group and severe stenosis in MES-positive group (P<0.05). There were 70 cases with no vertebral basilar artery stenosis, 86 cases with mild, moderate and severe stenosis, in which 14 cases were MES-positive and 72 cases were negative. There were significant differences in different locations of stenosis between the two groups. The proportion of multiple infarctions was significantly higher in MES-positive group than that of MES-negative group (P<0.05). The intracranial vertebral basilar artery stenosis and 75%of ver?tebral basilar artery stenosis were the independent risk factors of MES-positive. Conclusion Severe stenosis of the verte?bral basilar artery is more vulnerable to occur MES of posterior circulation, leading to cerebral infarction. Microemboli may be the cause of multiple infarctions in patients with vertebral basilar artery stenosis.

Study on the cerebral hemodynamic changes by transcranial Doppler ultrasonography from emergency ;periods to stable periods in severe acute encephalopathy children / 中国小儿急救医学

Objective To evaluate the correlations between the cerebral hemodynamic changes of severe acute encephalopathy with the clinical features from emergency periods to stable periods and the value of transcranial Doppler ultrasonography( TCD)in cerebral function assess. Methods Thirty patients with acute brain diseases by assisted mechanical ventilator from Jun 2014 to May 2015 in PICU were included and followed up to Nov 2015,then grouped by Glasgow Coma Scale( GCS),MRI,prognosis( mental sequelae after half a year). Each subject was examined through the temporal bone window by TCD at emergency peri-ods and stable periods. The systolic cerebral blood flow velocity( sCBFV),and pulsatility index( PI)of bilat-eral middle cerebral artery( MCA),anterior cerebral artery,posterior cerebral artery were analyzed. Multivari-ant analysis of variance,repeated measures analysis of variance was conducted to compare sCBFV and PI of MCA among groups in different clinical periods. The variants included sex,disease diagnosis,prognosis, MRI,GCS,and the first abnormal TCD. The variation within groups was tested via a Hotelling T2 test. All sCBFV and PI of each artery and the D-value of sCBFV between the different periods were compared accord-ing to the prognosis groups. Results (1)Five patients could be lateralized,and their lateralization of MRI focus was consistent with the abnormal sides of sCBFV in the stable periods.(2)The D-value of sCBFV in left MCA between the different periods in the poor prognosis group was significantly higher than that in the good prognosis group[(71. 93 ± 58. 21)cm/s vs.(33. 20 ± 30. 23)cm/s,t = -2. 287,P =0. 033].(3) Multivariant analysis of variance showed that GCS classification and disease diagnosis were significantly cor-related with the cerebral hemodynamic changes respectively(P =0. 042,0. 005,respectively).(4)sCBFV and PI of left MCA reduced significantly in the stable periods than those in the emergency periods( P =0. 002,0. 003,respectivly). Conclusion The cerebral hemodynamic changes by TCD from emergency peri-ods to stable periods are consistent with the clinical status,dynamic evaluation by TCD may facilitate the evaluation of brain dysfunction in the severe acute encephalopathy.

Measurement of Ophthalmic-arterial Blood-flow Velocity Using Transcranial Doppler Ultrasonography in Patients with Central Serous Chorioretinopathy

PURPOSE: To measure and compare the ocular blood-flow velocity of ophthalmic artery in patients with central serous chorioretinopathy (CSC); affected eyes, asymptomatic fellow eyes, and CSC resolved eyes using transcranial Doppler ultrasonography. METHODS: A total of 31 patients (age 20-52 years) with CSC were evaluated using power motion mode Doppler 150 digital transcranial Doppler ultrasonography. The peak systolic velocity (PSV), peak diastolic velocity (PDV), and resistance index (RI) were measured in the ophthalmic artery of both affected and asymptomatic fellow eyes. After 2 months, 23 patients with resolved serous retinal detachment underwent repeated measurement of the above hemodynamic indices. RESULTS: The PSV and PDV of the ophthalmic artery were 30.05 ± 5.34 cm/sec and 14.07 ± 2.90 cm/sec in affected eyes and 33.03 ± 2.00 cm/sec and 17.17 ± 2.76 cm/sec in asymptomatic fellow eyes, respectively. Both indices were significantly lower in affected eyes (p = 0.004, p < 0.001, respectively). The RI was 0.52 ± 0.08 in affected eyes and 0.43 ± 0.04 in fellow eyes, a significant difference (p < 0.001). After 2 months, in 23 eyes with resolved CSC, the PSV and PDV were 32.94 ± 6.24 cm/sec and 15.54 ± 2.88 cm/sec, respectively. Both indices were significantly higher than at baseline (p = 0.031, p = 0.045, respectively). However, RI was 0.48 ± 0.04 and was not significantly different (p = 0.073). CONCLUSIONS: The CSC-affected eyes showed lower ocular blood-flow velocity and higher RI than the asymptomatic fellow eyes. The ocular blood-flow velocity was increased as CSC was resolved. These findings provide insights into the ophthalmic arterial vascular factors related to the pathogenesis of CSC.

Selective Carotid Shunting Based on Intraoperative Transcranial Doppler Imaging during Carotid Endarterectomy: A Retrospective Single-Center Review

BACKGROUND: Carotid endarterectomy (CEA) with selective shunting is the surgical method currently used to treat patients with carotid artery disease. We evaluated the incidence of major postoperative complications in patients who underwent CEA with selective shunting under transcranial Doppler (TCD) at our institution. METHODS: The records of 45 patients who underwent CEA with TCD-based selective shunting under general anesthesia from November 2009 to June 2015 were reviewed. The risk factors for postoperative complications were analyzed using univariate and multivariate analysis. RESULTS: Preoperative atrial fibrillation was observed in three patients. Plaque ulceration was detected in 10 patients (22.2%) by preoperative computed tomography imaging. High-level stenosis was observed in 16 patients (35.5%), and 18 patients had contralateral stenosis. Twenty patients (44.4%) required shunt placement due to reduced TCD flow or a poor temporal window. The 30-day mortality rate was 2.2%. No cases of major stroke were observed in the 30 days after surgery, but four cases of minor stroke were noted. Univariate analysis showed that preoperative atrial fibrillation (odds ratio [OR], 40; p=0.018) and ex-smoker status (OR, 17.5; p=0.021) were statistically significant risk factors for a minor stroke in the 30-day postoperative period. Analogously, multivariate analysis also found that atrial fibrillation (p<0.001) and ex-smoker status (p=0.002) were significant risk factors for a minor stroke in the 30-day postoperative period. No variables were identified as risk factors for 30-day major stroke or death. No wound complications were found, although one (2.2%) of the patients suffered from a hypoglossal nerve injury. CONCLUSION: TCD-based CEA is a safe and reliable method to treat patients with carotid artery disease. Preoperative atrial fibrillation and ex-smoker status were found to increase the postoperative risk of a small embolism leading to a minor neurologic deficit.

Application of transcranial doppler ultrasonography in the disease of increased intracranial pressure in children / 中国小儿急救医学

The transcranial doppler ultrasonography (TCD) is a non-invasive detection methods of evaluating intracranial artery.Since the 1980s,TCD has been extensively used in various fields of clinical work.Because of its simple operation,good repeatability,and the continuous bedside observation of patients,TCD is especially suitable for severe patients.Increased intracranial pressure is one of the important reasons for the deadly disease in children,it can make the cerebral blood flow perfusion decreased,causing serious consequences,such as brain dysfunction,so intracranial pressure monitoring has important clinical significance.TCD as a noninvasive monitoring tool,can monitor the patients with increased intracranial pressure dynamically,according to the blood flow velocity,the related parameters and the wave of cerebral hemodynamics,so as to achieve the purpose of monitoring intracranial pressure change.This article focused on the TCD application progress in several common children's diseases of increased intracranial pressure.

Nova metodologia de Doppler transcraniano funcional durante tarefa motora unimanual / New methodology for functional transcranial Doppler during an unimanual motor task

INTRODUÇÃO: O Doppler Transcraniano funcional pode avaliar mudanças na velocidade do fluxo sanguíneo encefálico associadas a tarefas cognitivas e/ou sensitivo-motoras. Mede de maneira indireta a atividade metabólica de regiões cerebrais, segundo o princípio do acoplamento neurovascular. Os objetivos deste estudo foram: desenvolver um novo método de análise de Doppler transcraniano funcional para análise da lateralização hemisférica e verificar a capacidade deste novo método em diferenciar a lateralização hemisférica durante a execução de uma tarefa motora unimanual por indivíduos saudáveis. Adicionalmente, a lateralização hemisférica foi correlacionada com a preferência manual nestes indivíduos. MÉTODOS: Treze indivíduos saudáveis foram submetidos a um exame de Doppler transcraniano funcional durante uma prova de ativação motora manual (oposição de dedos). As sessões de Doppler transcraniano funcional foram realizadas com aparelho Doppler-Box Transcranial Doppler Unit. A prova manual compreendeu uma sequência de movimentos de oposição do primeiro e segundo dedos (thumb-tofinger opposition movement) realizado por uma mão e depois pela outra, em uma frequência de 1 movimento por segundo (1Hz) fornecida por um metrônomo digital. Durante a execução dos movimentos, foram insonadas simultaneamente as artérias cerebrais médias direita e esquerda. Para interpretação dos dados de Doppler transcraniano funcional desenvolvemos um novo programa de análise denominado FDAT, que tem vantagens de sofrer mínima influência de artefatos de ruído no sinal e de não assumir um formato pré-determinado da resposta hemodinâmica cerebral. Foi calculado um índice de lateralização (IL) como a diferença entre a velocidade relativa média da época de ativação e a velocidade relativa média da época de repouso para cada prova motora. Foi calculada a diferença dos valores de IL (ILe - ILd) provenientes da análise com cada método, obtendo-se um índice de ativação, próprio de cada sujeito...

INTRODUCTION: Functional transcranial Doppler is a method for the assessment of changes in blood flow velocity of the middle cerebral artery. An asymmetric increase in blood flow velocity is a marker of hemispheric lateralization during unimanual motor task erformance. The aims of this study were to propose a novel and efficient method for functional transcranial Doppler analysis based on cubic smoothing splines, and to verify the ability of this method to identify hemispheric lateralization during unimanual motor task performance in healthy subjects. In addition, hemispheric lateralization was correlated with handedness in these subjects. METHODS: Thirteen healthy subjects participated in the study. Blood flow velocities in the right and left middle cerebral arteries were recorded using functional transcranial Doppler during a finger-tapping task with either the right or left hand. Data were analyzed with a multi-step new method that included: baseline determination, raw data normalization, smoothing, lateralization Index calculation, definition of rest and motor task epochs and activation Index calculation. A positive activation Index reflects right-hemisphere lateralization and a negative activation index, left hemisphere lateralization. RESULTS: There was a statistically significant difference between the activation index obtained during right or left hand movements (p=0.02). Hand dominance was significantly correlated with asymmetry in hemispheric lateralization assessed with functional transcranial Doppler (rho = 0.85, p<0.001). CONCLUSIONS: This novel method for functional transcranial Doppler analysis was capable to assess the hemispheric lateralization during motor task performance, and correlated well with handedness. It is a practical, non-invasive and unexpensive tool for the assessment of hemispheric lateralization.

Novo método de hipotermia encefálica exclusiva através de resfriamento nasofaríngeo: modelo experimental em suínos / New method of exclusive brain hypothermia by means of nasopharyngeal cooling: swine experimental study

INTRODUÇÃO: Evidências relevantes acerca dos benefícios da hipotermia terapêutica provieram da utilização de técnicas de resfriamento sistêmico. Essas técnicas, no entanto, podem causar complicações graves que poderiam ser evitadas com métodos de hipotermia encefálica seletiva. O presente estudo objetiva: 1) verificar a viabilidade da hipotermia encefálica exclusiva através de um sistema de resfriamento nasofaríngeo concomitante ao de preservação da temperatura corpórea em suínos e 2) investigar os efeitos da hipotermia encefálica exclusiva nas variáveis fisiológicas sistêmicas e encefálicas. MÉTODOS: Dez suínos híbridos foram submetidos a resfriamento nasofaríngeo durante 60 minutos e subsequente reaquecimento espontâneo. Foram obtidos dados referentes a: pressão arterial média, débito cardíaco, temperatura encefálica, pressão parcial de oxigênio do tecido encefálico (PbtO2, do inglês, pressure of brain tissue O2), velocidade do fluxo sanguíneo nas artérias encefálicas, índice de resistência e índice de pulsatilidade. RESULTADOS: O resfriamento nasofaríngeo associou-se à um decréscimo gradual da temperatura encefálica, que foi mais marcante no hemisfério cerebral esquerdo (p < 0,01). Neste hemisfério, houve redução de 1,47 ± 0,86°C nos primeiros 5 minutos (p < 0,01), 2,45 ± 1,03°C aos 10 minutos e 4,45 ± 1,36°C após 1 hora (p < 0,01). A diferença entre as temperaturas cerebral sistêmica foi 4,57 ± 0,87°C (p < 0,01). As temperaturas centrais (retal, esofágica e da artéria pulmonar), assim como a hemodinâmica encefálica e sistêmica, mantiveram-se estáveis durante o procedimento. Houve diminuição significativa da PbtO2, concomitantemente ao decréscimo da temperatura encefálica. CONCLUSÕES: A indução de hipotermia encefálica exclusiva é possível através de resfriamento nasofaríngeo associado a medidas de preservação da temperatura sistêmica. O resfriamento encefálico exclusivo não influencia as funções hemodinâmicas sistêmicas e encefálicas...

INTRODUCTION: Relevant evidences for the use of therapeutic hypothermia derive from studies using whole body cooling methods. These methods can lead to serious complications. To avoid such complications, selective brain cooling methods were developed. The objective of this study was: 1) to verify the feasibility of exclusive brain hypothermia by means of nasopharyngeal cooling along with measures of systemic temperature preservation in an experimental swine model, and 2) to investigate the influence of the exclusive brain cooling on cerebral and systemic hemodynamics as well as on cerebral oxygenation. METHODS: Ten hybrid swine underwent nasopharyngeal cooling for 60 minutes, followed by spontaneous rewarming. A number of physiological variables were monitored: arterial blood pressure, cardiac output, temperature in the right and left cerebral hemispheres, pressure of brain tissue O2, cerebral blood flow velocities, resistance index, and pulsatility index. RESULTS: Nasopharyngeal cooling was associated with decrease in brain temperature, which was more significant in the left cerebral hemisphere (p < 0,01). There was a reduction of 1.47 ± 0.86°C in the first 5 minutes (p < 0.01), 2.45 ± 1.03°C within 10 min, and 4.45 ± 1.36°C after 1 hour (p < 0.01). The brain-core gradient was 4.57 ± 0.87°C (p < 0,001). Rectal, esophageal, and pulmonary artery temperatures, as well as brain and systemic hemodynamics, remained stable during the procedure. PbtO2 values significantly decreased following the brain cooling. CONCLUSION: Achievement of exclusive brain hypothermia is feasible by means of nasopharyngeal cooling associated with measures of systemic temperature preservation. Selective brain cooling does not influence both systemic and cerebral hemodynamics, except PbtO2, which decreased significantly...

Paradoxical Cerebral Embolism Associated With Isolated Pulmonary Arteriovenous Fistula

No abstract available.

Study of cerebrovascular reserve capacity in obstructive sleep apnea-hypopnea syndrome / 中国综合临床

Objective To assess cerebrovascular reserve capacity in patients with obstructive sleep apnea-hypopnea syndrome(OSAHS).Methods One hundred and fourteen patients with OSAHS and 43 normal persons were enrolled in this study.The patients were divided into mild,moderate,severe according to apnea hypopnea index (AHI) and LSaO2 (lowest arterial oxygen saturation).All the patients and normal persons were routinely examined using transcranial Doppler (TCD) and end-tidal carbon dioxide partial pressure(ETCO2) to evaluate cerebrovascular reserve.Hypercapnia was induced by inhaling the CO2 which produced by the patients themselves,and hypocapnia was elicited by voluntary hyperventilation.Results CVR in the severe and moderate OSAHS were significantly lower than that in the control group [ (1.80 ± 1.34) ％/mm Hg and (1.43 ±1.05)％/mm Hg vs (2.93 ±0.93)％/mm Hg,P ＜0.05] when patients in the condition of hypocapnia.And there was no significant difference on CRV between the mild OSAHS group and control group [ (2.53 ±1.83 ) ％/mm Hg vs ( 2.93 ± 0.93 ) ％/mm Hg,P ＞ 0.05 ].When patients in the condition of Hypercapnia,CRV in the severe and moderate OSAHS were also significantly lower than that in the control group [ ( 1.83 ±1.32) ％/mm Hg and (1.08 ± 1.00)％/mm Hg vs (3.32 ± 1.53)％/mm Hg,P ＜ 0.05),AHI was negatively correlated with the cerebrovascular reserve at the condition of hypercapnia and hypocapnia (r=-0.665,-0.721; P ＜ 0.05 ).Conclusion Inhaling CO2 is a effective method for assessing CVR.Cerebrovascular reserve capacity is associated with AHI.Reduced CVR causes hemodynamics change being severe hypoxia in the moderate and severe OSAHS.

Aplicação clínica da ultrassonografia craniana com Doppler em neonatos prematuros de muito baixo peso / Clinical application of transcranial Doppler ultrasonography in premature, very-low-birth-weight neonates

OBJETIVO: Analisar o valor do diagnóstico precoce de alterações hemodinâmicas em hemorragias e eventos hipóxico-isquêmicos pela avaliação de imagens e mensuração do índice de resistência por meio da ultrassonografia craniana com Doppler em neonatos prematuros de muito baixo peso. MATERIAIS E MÉTODOS: Cinquenta neonatos prematuros de muito baixo peso foram submetidos a ultrassonografia craniana com Doppler com a técnica transfontanela anterior e transtemporal sequenciais. RESULTADOS: Foram detectadas alterações cerebrais em 32 por cento dos prematuros, sendo 22 por cento com hemorragia intracraniana, 8 por cento com leucomalácia periventricular e 2 por cento com toxoplasmose. Dentre os 34 casos (68 por cento), do total de neonatos, nos quais não foram detectadas lesões cerebrais pela ultrassonografia craniana, 18 (53 por cento) apresentaram alterações no índice de resistência. O índice de resistência variou conforme a época do exame. CONCLUSÃO: Existe correlação entre a presença de alterações na hemodinâmica cerebral e subsequente desenvolvimento de hemorragias e lesões hipóxico-isquêmicas, pela mensuração do índice de resistência. Alterações do índice de resistência, embora não preditoras de morte, estão relacionadas com a gravidade do quadro clínico em neonatos prematuros de muito baixo peso.

OBJECTIVE: The present study was aimed at analyzing the value of the early diagnosis of hemodynamic changes in hemorrhages and hypoxic-ischemic events in premature, very-low-birth-weight neonates through the evaluation of images and resistance index measurement by means of transcranial Doppler ultrasonography. MATERIALS AND METHODS: Fifty premature, very-low-birth-weight neonates were submitted to transcranial Doppler ultrasonography with sequential transfontanellar and transtemporal techniques. RESULTS: Cerebral abnormalities were detected in 32 percent of the neonates (22 percent with intracranial hemorrhage, 8 percent with periventricular leukomalacia, and 2 percent with toxoplasmosis). Among the 34 cases (68 percent) of neonates in whom no brain lesion was detected at transcranial Doppler ultrasonography, 18 (53 percent) presented changes in the resistance index. Such resistance index varied according to the time of the examination. CONCLUSION: There is a correlation between the presence of cerebral hemodynamic changes demonstrated by resistance index measurements and the subsequent development of hemorrhages and hypoxic-ischemic lesions. Although not being a death predictor, changes in the resistance index are associated with the severity of the clinical conditions in preterm, very-low-birth-weight neonates.

Correlation analysis of carotid artery color Doppler flow imaging indices and transcranial Doppler ultrasound indices / 第二军医大学学报

Objective: To analyze the correlation of carotid artery color Doppler flow imaging (CDFI) indices and transcranial Doppler ultrasound (TCD) indices. Methods: The clinical data of 118 hospitalized patients with ischemic cerebrovascular diseases were included in the present study and all of them received CDFI and TCD examination. The patients were divided into two groups according to presence of carotid plaque group; t-test was used to identify the correlation between the presence of carotid plaque and TCD indices. Meanwhile, the patients were also divided into three groups according to the quantity/distribution of plaque) one-way ANOVA(F-test) and student-Newman-Keuls were used to identify the correlation of the quantity/distribution of plaque with TCD indices. The patients with carotid plaque were divided into three groups according to the plaque texture) one-way ANOVA(F-test) and student-Newman-Keuls were used to identify the correlation of the quality of plaque with TCD indices. Meanwhile, linear correlation was used to identify the correlation of the common carotid intimal-medial thickness (CCA IMT) with TCD indices. Results: The resistance index (RI), pulsatile index (PI) and ratio of peak systolic to least diastolic flow velocity (S/D) of bilateral middle cerebral arteries and basal artery in patients with carotid plaque were significantly higher than those in patients without carotid plaque (P<0.05); other TCD indices including Vp, Vd, and Vm were not significantly different. The quantity/distribution of plaque, the quality of plaque and CCA IMT were not correlated with TCD indices. Conclusion: No CDFI indices, except for the presence of carotid plaque, are correlated with TCD indices. Combined application of CDFI and TCD indices can better reflect the structure and hemodynamic status of cerebral vessels.

Changes of cerebral blood flow and cerebral autoregulation during propofol or sevoflurane anaesthesia in patients undergoing gynecologic laparoscopic surgery / 复旦学报（医学版）

Objective To observe the effects of propofol or sevoflurane combined with remifentanil on cerebral blood flow (CBF) and cerebral autoregulation in patients undergoing gynecologic laparoscopic surgery. Methods Forty patients were randomly divided into two groups: the propofol group (group P, n=20) and the sevoflurane group (group S, n=20). Anaesthesia was induced with target-controlled infusion (TCI) of propofol and remifentanil in group P, with an inhaled induction of sevoflurane and TCI of remifentanil in group S, respectively. The depth of anesthesia was regulated according to bispectral index (BIS). The pressure of end-tidal carbon dioxide (P_(ET)CO_2) was kept at 35-40 mmHg by mechanical ventilation. The mean arterial pressure (MAP), heart rate (HR), pressure of arterial carbon dioxide (PaCO_2), P_(ET)CO_2, time-averaged peak flow velocity (TAP) and the transient hyperaemic response ratio (THRR) were recorded at 7 different time points: supine position (T_1) and supine lithotomy position before induction (T_2), the instant and 5 min after tracheal intubation (T_3,T_4), the instant and 15 min after abdominal CO_2 insufflation and trendelenburg-lithotomy position (T_5,T_6), and 10 min after the deflation abdomen (T_7), respectively. Results Compared with the baseline values at T_1, TAP was not significantly changed at T_2, T_5, or T_6 in group P, but was markedly decreased at T_3, T_4 and T_7. TAP in group S only decreased at T_4 and T_7, while it was much higher than that in group P at T_3. In group S, THRR was markedly lowered at T_3 compared with that at T_1; but in group P, it showed a significant increase at T_3. Conclusions Combined with remifentanil, propofol decreased CBF, but has no effect on the brain self-regulation. When inhaled in high concentrations, sevoflurane significantly reduces the brain self-regulation. Intraoperation pneumoperitoneum and postural factor significantly increase CBF, playing a stronger role than the narcotic drugs in clinical dosage (propofol, sevoflurane), without any influence on the brain self-regulation.

The study of the cerebrovascular reserve in patients with diabetes or the combined diabetes and cerebral infarction / 中国糖尿病杂志

Objective To assess the association of cerebrovascular reserve(CVR) with diabetes(DM)、hypertensive atherosclerotic lacunar infarction(HALI),hypertension(HT) and diabetic lacunar infarction(DLI) by means of transcranial Doppler ultrasonography (TCD) with breath-holding maneuver.Methods The breath-holding index (BHI), which was the percentage increase in middle cerebral artery(MCA) blood flow velocity as index of CVR assessment,was detected during breath-holding by TCD and breath-holding technique in 30 diabetic patients,30 hypertensive atherosclerotic lacunar infarction patients,30 hypertension patients and 30 diabetic lacunar infarction patients. Results There was significant difference in the ascending rates of Vm and BHI between diabetic group and diabetic lacunar infarction group,diabete lacunar infarction group and hypertensive atherosclerotic lacunar infarction group,hypertension group and diabetic group (all P<0.05). Conclusions Diabetes can more significantly impair CVR than hypertension. Diabetic lacunar infarction can more significantly impair CVR than diabetes. Diabetic lacunar infarction can more significantly impair CVR than hypertensive atherosclerotic lacunar infarction .

Relationship between vertebral artery incisures and the diseased regions evaluated using transcranial Doppler ultrasound / 中华医学超声杂志（电子版）

Objective To explore the relationship between the incisure changes in the intracranial vertebral artery (VA) segments on transcranial Doppler (TCD) and their diseased regions. Methods Incisure changes in VA intraeranial segments on TCD in 24 cases were found. Digital subtract angiography (DSA), computed tomography angiography (CTA)or coler Doppler flow imaging (CDFI)of carotid arteries were performed to confirm their diseased regions. Results (1)The group with end-systolic and pre-diatolic wide incisures was found in 9 cases: DSA or CTA showed 5 cases with severe stenosis, 2 cases with occlusion and 2 cases with congenital tenuity of the affected vertebral artery proximal part(VA-Pr). Within the above 8 cases, ipsilateral subclavian artery (SubA) was normal, 1 case was complicated with moderate stenosis of ipsilateral SubA,and 1 case was complicated with occlusion of contralateral SubA. Haemodynamics test showed (1)negative; (2)The group with systolic incisures was in 12 cases, and 12 patients were divided into two groups based on the haemodynamics test : ① positive group was in 6 cases. DSA showed that VA-Pr was normal but SubA had impaired with different degrees; ② negative group was in 6 cases. DSA showed VA-Pr was with occlusion in 4 cases and 2 cases was with congenital tenuity; The above 2 cases were complicated with stenosis of ipsilateral SubA and in 4 cases ipsilateral SubA were normal; (3) The group with small vibrated sharp waves on Doppler was in 3 cases, and DSA showed VA-Pr occlusion in 3 cases. In the 3 cases,one case was complicated with occlusion of ipsilateral SubA. Blood stealing was present in cervical muscular branches but not present between vertebral arteries . Ipsilateral SubA were normal in 2 cases. Haemodynamic tests showed negative. Conclusions VA incisures were not only present in the early subclavian steal syndrome (SSS) but also were found in the patients with impaired SubA . However, blood steal pathway is imperfect, and would be found in affected VA-Pr or congenital tenuity. Haemodynamic tests can help identify the above situation. The TCD screening method can be used in the routine diagnosis for SubA and VA from proximal to intracranial segments involvement, but there are limitations to some extent. It needs to combine with DSA and CDFI for diagnosis.