Head Position on Cerebral Haemodynamics in Acute Ischemic Stroke and Controls
The Effects of Head Positioning on Beat to Beat Cerebral Haemodynamics: a Comparison Between Acute Stroke Patients and Healthy Control Subjects
Visão geral do estudo
Descrição detalhada
In the United Kingdom (UK) alone, approximate 100,000 people suffer a stroke each year. Improved management of stroke patients not only reduces morbidity and mortality, but also reduces the cost of long term social care.
The brain has control systems (i.e.cerebral autoregulation) to maintain blood flow to the brain, over a relatively wide blood pressure range. Cerebral Autoregulation can be described as static, reflecting the integrity of such mechanisms over time, or dynamic, occurring in response to sudden fluctuations in perfusion pressure. When blood pressure drops, small arteries increase in size to restore flow levels, and when blood pressure rises, they narrow to protect the most delicate blood vessels. It is known that sudden decompensated blood pressure (BP) changes can occur after stroke, this could result in brain bleeding and swelling when there is uncontrolled increased blood flow, or reduce the viability of tissue surrounding the stroke area when there is reduced blood flow to the brain.
It is known that the clot busting agent (Alteplase), the main effective treatment used in the acute stroke can only improve blood flow in already blocked arteries in 50% of patients. Therefore, as well as attempts to treat blockage of major vessel, improving the blood flow through vessel that bypass the blocked vessel around the stroke area (penumbra) could be another potential therapeutic approach in acute ischaemic stroke patients. A simple way of increase blood flow to these penumbral area might be just lower the head of acute stroke patients into a lying flat position. Several observational studies have investigated the effects of head positioning on blood flow to the brain in a healthy population, however few studies carried out on acute ischaemic stroke patients so far.
Cerebral autoregulation can be assessed non-invasively by the use of Trans Cranial Doppler (TCD). This means using ultrasound probes over both sides of the head to measure changes in blood flow in one of the main brain arteries (the middle cerebral artery) in response to beat to beat changes in blood pressure dynamic cerebral autoregulation. This research will use the noninvasive technique of Trans Cranial Doppler to see how blood flow changes during different head position between acute ischaemic stroke patients and healthy controls, as well as over time during recovery after a stroke. This knowledge will help us to understand the changes in brain blood flow control and blood pressure in stroke patients, with implications of diagnosis, prognosis, and treatment of the disease.
Tipo de estudo
Inscrição (Real)
Contactos e Locais
Locais de estudo
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Leicester, Reino Unido, LE1 5WW
- University Hosptial of Leicester NHS Trust
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Critérios de participação
Critérios de elegibilidade
Idades elegíveis para estudo
Aceita Voluntários Saudáveis
Gêneros Elegíveis para o Estudo
Método de amostragem
População do estudo
Descrição
Inclusion Criteria:
- Informed volunteer consent, patient consent or personal consultee declaration form
- Male or female, aged 18 years or above
- Able (in the Investigator's opinion) and willing to comply with all study requirements
- Willing to allow his or her General Practitioner (GP) to be notified of participation in the study Stroke Patient-specific Inclusion Criteria
- Clinical diagnosis of ischaemic stroke within 24 hours of onset (for patients waking with a stroke, time of onset will be taken to be the time when the patient was last asymptomatic)
Exclusion Criteria:
Male or Female, aged under 18 years
- Unable (in the Investigator's opinion) or unwilling to comply with any study requirements
- Participants who practice yoga regularly
- Female participants who are pregnant, lactating or planning pregnancy during the course of the study Stroke Patient-specific Exclusion Criteria
- Clinical diagnosis of stroke greater than 24 hours from onset
- Having had a resolved transient ischaemic attack (TIA) (i.e. neurological symptoms completely resolved upon hospital presentation)
- Definite clinical indication to 'sitting up' (≥30⁰) head position (i.e. pneumonia, decompensated heart failure)
- Definite clinical indication to lying flat (0⁰) head position (i.e. shock, airways obstruction)
- Co-morbidity with anticipated life expectancy less than 3 months
Plano de estudo
Como o estudo é projetado?
Detalhes do projeto
Coortes e Intervenções
Grupo / Coorte |
Intervenção / Tratamento |
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Healthy controls
healthy controls subjects who have age, sex and Blood pressure matched with the acute ischaemic stroke patient
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patient can be allocated to the transient change of the head position, persistent lying flat position in the first 24 hours of the hospital admission and persistent sitting up in the first 24 hours of the hospital admission
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AIS patient-transient arm
transient change of head position from lying flat (0 degree) to sitting up (30 degree)
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patient can be allocated to the transient change of the head position, persistent lying flat position in the first 24 hours of the hospital admission and persistent sitting up in the first 24 hours of the hospital admission
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AIS patient - persistent lying flat
lying flat (0 degree) head position for the first 24 hours in the hospital admission
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patient can be allocated to the transient change of the head position, persistent lying flat position in the first 24 hours of the hospital admission and persistent sitting up in the first 24 hours of the hospital admission
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AIS patient - persistent sitting up
sitting up ( 30 degree) head position for the first 24 hours in the hospital admission
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patient can be allocated to the transient change of the head position, persistent lying flat position in the first 24 hours of the hospital admission and persistent sitting up in the first 24 hours of the hospital admission
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O que o estudo está medindo?
Medidas de resultados primários
Medida de resultado |
Descrição da medida |
Prazo |
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cerebral blood flow velocity
Prazo: within 24 hours, 72 hours and 3 months of the stroke symptom onset
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percentage change of the cerebral blood flow velocity in response to change of the head position within 24 hours, 72 hours and 3 months of the stroke symptom onset
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within 24 hours, 72 hours and 3 months of the stroke symptom onset
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Medidas de resultados secundários
Medida de resultado |
Descrição da medida |
Prazo |
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dynamic cerebral autoregulation
Prazo: within 24 hours, 72 hours and 3 months of stroke symptom onset
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change of dynamic cerebral autoregulation within 24 hours, 72 hours and 3 months of the stroke symptom onset.
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within 24 hours, 72 hours and 3 months of stroke symptom onset
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Neurovascular coupling
Prazo: within 24 hours, 72 hours and 3 months of stroke symptom onset
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change of neurovascular coupling within 24 hours, 72 hours and 3 months of stroke symptom onset
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within 24 hours, 72 hours and 3 months of stroke symptom onset
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Carbon dioxide reactivity
Prazo: within 24 hours, 72 hours and 3 months of stroke symptom onset
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change of carbon dioxide reactivity within 24 hours, 72 hours and 3 month of stroke symptom onset.
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within 24 hours, 72 hours and 3 months of stroke symptom onset
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Colaboradores e Investigadores
Patrocinador
Investigadores
- Investigador principal: Thompson G Robinson, MD, FRCP, University of Leicester
Publicações e links úteis
Datas de registro do estudo
Datas Principais do Estudo
Início do estudo
Conclusão Primária (Real)
Conclusão do estudo (Real)
Datas de inscrição no estudo
Enviado pela primeira vez
Enviado pela primeira vez que atendeu aos critérios de CQ
Primeira postagem (Estimativa)
Atualizações de registro de estudo
Última Atualização Postada (Real)
Última atualização enviada que atendeu aos critérios de controle de qualidade
Última verificação
Mais Informações
Termos relacionados a este estudo
Termos MeSH relevantes adicionais
Outros números de identificação do estudo
- 0538
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