New methodology for functional transcranial Doppler during an unimanual

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. A comparação do índice de ativação durante a movimentação da mão direita, e durante a movimentação da mão esquerda, foi feita com o teste de Wilcoxon. A correlação entre o índice de ativação e a preferência manual avaliada pelo Inventário de Edimburgo foi avaliada pelo coeficiente rho de Spearman. RESULTADOS: Houve uma diferença estatisticamente significante entre o IA obtido durante a movimentação da mão direita ou da mão esquerda (p=0,02). Houve correlação estatisticamente significante entre a preferência manual e a assimetria na lateralização hemisférica identificada pelo Doppler Transcraniano funcional (rho = 0.85, p < 0.001). CONCLUSÕES: A análise do Doppler Transcraniano funcional mostrou-se viável pelo método proposto, capaz de avaliar o grau de lateralização hemisférica em uma prova de ativação motora, com boa correlação com a preferência manual. Trata-se de uma ferramenta prática, não invasiva e de baixo custo para a avaliação da lateralização hemisférica em determinadas provas funcionaisINTRODUCTION: 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 performance. 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

Diabetes, hyperglycemia and the management of cerebrovascular disease

Purpose of review Hyperglycemia is frequent in patients with cerebrovascular disease. This review article aims to summarize the recent evidence from observational studies that examined the adverse cerebrovascular effects of dysglycemic states as well as interventional studies assessing intensive management strategies for hyperglycemia. Recent findings In recent years, diabetes, prediabetic states and insulin resistance and their association with cerebrovascular disease were an important focus of research. The cerebrovascular consequences of these metabolic abnormalities were found to extend beyond ischemic stroke to covert brain infarcts, other structural brain changes and to cognitive impairment with and without dementia. Interventional studies did not reveal that more intensive management of chronic hyperglycemia and of hyperglycemia in the setting of acute stroke improves outcome. There is clear evidence, however, that the overall management of multiple risk factors and behavior modification in patients with dysglycemia may reduce the burden of cerebrovascular disease. Summary Observational studies reveal the growing burden and adverse cerebrovascular effects of dysglycemic states. Currently available interventional studies assessing more intensive strategies for the management of hyperglycemia did not prove, however, to be effective. We discuss the current evidence, pathophysiological considerations and management implications.National Institutes of Health (NIH)Israeli Ministry of Healt

Cerebral sinus vein thrombosis following sneezing - Case Report

Cerebral sinus vein thrombosis (CVT) is a relatively rare neurovascular entity, usually associated with acquired or genetic hypercoagulable states, and in many cases it remains idiopathic. Trauma is also associated with CVT among patients with major head or neck trauma, including penetrating injuries. However, CVT associated with acceleration trauma has only been described in few cases so far. We present an unusual case of a 19-year-old woman with no past medical history, admitted with an extensive CVT following sneezing. A thorough investigation did not reveal any other potential etiology or risk factor other than estrogen-containing oral contraceptives. The patient was treated with anti-coagulation and improved clinically with complete recanalization on follow-up imaging. This case suggests acceleration trauma may be a potential factor of risk for CVT

A Rare Case of Cardio-Embolic Spinal Stroke in a Young Female - Case Report

Spinal cord infarction (SCI) is a rare neurovascular disorder, often presented with acute spinal cord syndrome. The diagnosis is generally made clinically, with appropriate neuroimaging to confirm the diagnosis and exclude other causes. We present an unusual case of a 48-year-old woman with no relevant past medical history, admitted with acute paraparesis and spinal cord infarct on magnetic resonance imaging (MRI). A thorough investigation revealed asymptomatic unknown heart failure secondary to hypertrophic cardiomyopathy (HCM), suggestive of a cardioembolic etiology. The patient was treated with anti-coagulation and improved significantly with physical rehabilitation

Lhermitte's sign and vitamin B12 deficiency: case report

CONTEXT AND OBJECTIVE: Lhermitte's sign, a classical neurological sign, is a rare manifestation of vitamin B12 deficiency. The aim here was to report on a case of an elderly patient with vitamin B12 deficiency whose first clinical manifestation was the presence of Lhermitte's sign. CASE REPORT: We describe an elderly patient with vitamin B12 deficiency who presented cognitive dysfunction, peripheral polyneuropathy and sensory ataxia, and whose first clinical manifestation was the presence of Lhermitte's sign. This sign is one of the rarest manifestations of vitamin B12 deficiency