Cerebrovascular Reactivity in Obstructive Sleep Apnea (OSA) Subjects
Spatial and Temporal Response of Cerebrovascular Response in OSA
Obstructive sleep apnea (OSA) is a prevalent sleep breathing disorder in the general population in which recurrent collapse of the upper airway occurs during sleep. OSA is more prevalent in subjects with stroke and is associated with a 3 fold increased risk of stroke. This makes it a serious public health problem. Approximately 50% of subjects with OSA are asymptomatic and are often only detected following investigation for the cause of heart disease or a stroke. In subjects who are treated for OSA many are intolerant or poorly compliant with treatment. Therefore, the identification of those subjects with OSA most at risk of adverse consequences such as stroke is important, so that treatment compliance can be improved.
Therfore, the investigators want to determine if compared to subjects without OSA, subjects with OSA have evidence of increased stroke risk by assessment of changes in cerebral blood flow (cerebrovascular reactivity) as measured on Doppler ultrasound of the middle cerebral artery (TCD) and blood oxygen level-dependent magnetic resonance imaging of patterns of cerebral blood flow (BOLD MRI) to two stimuli. These stimuli include increased carbon dioxide concentrations (causes increased cerebral blood flow) and reduced oxygen concentrations (causing decreased cerebral blood flow). In order to deliver these stimuli the investigators will use a special machine (RespiractTM) which allows for the precise control of carbon dioxide and oxygen concentrations in the lungs and blood. The precise control of carbon dioxide and oxygen in conjunction with BOLD MRI has enabled the production of detailed maps of the brain that identify areas of healthy and abnormal blood supply.
Descripción general del estudio
Estado
Condiciones
Descripción detallada
Tipo de estudio
Inscripción (Anticipado)
Contactos y Ubicaciones
Ubicaciones de estudio
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Ontario
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Toronto, Ontario, Canadá, M5G 2N2
- Reclutamiento
- Toronto Gneral Hospital
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Investigador principal:
- Clodagh Ryan, MD
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Sub-Investigador:
- J Fisher, MD
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Sub-Investigador:
- J Duffin, PhD
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Sub-Investigador:
- D Mikulis, MD
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Sub-Investigador:
- a Battisti, BSc
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Sub-Investigador:
- O Pucci, BSc
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Criterios de participación
Criterio de elegibilidad
Edades elegibles para estudiar
Acepta Voluntarios Saludables
Géneros elegibles para el estudio
Método de muestreo
Población de estudio
Descripción
Inclusion Criteria:
- Subjects referred for sleep studies
Exclusion Criteria:
- Known cardiac, neurological or major liver or kidney disease -
- Cardioverter/defibrillator metal heart valve or pacemaker
- Vascular stent implanted within 6 weeks
- Severe claustrophobia
- Pregnancy
- Shrapnel or history of ophthalmic foreign body
- Resting oxygen saturation on room air < 95%
- Insulin-dependent diabetes
- Obstructive or restrictive lung disease such that subject is unable to walk up 2 flights of stairs
- Major depression.
Plan de estudios
¿Cómo está diseñado el estudio?
Detalles de diseño
- Modelos observacionales: Grupo
- Perspectivas temporales: Futuro
Cohortes e Intervenciones
Grupo / Cohorte |
|---|
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Control without Sleep Apnea
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Subjects with Sleep Apnea
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¿Qué mide el estudio?
Medidas de resultado primarias
Medida de resultado |
Periodo de tiempo |
|---|---|
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Document the diurnal differences in global CVR as measured by TCD, between those with and without OSA
Periodo de tiempo: Between 8pm and 7am approximately
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Between 8pm and 7am approximately
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Medidas de resultado secundarias
Medida de resultado |
Periodo de tiempo |
|---|---|
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Use BOLD MRI to quantify global and regional CVR in various regions and vascular territories of the brain in subjects with OSA.
Periodo de tiempo: one week
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one week
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Colaboradores e Investigadores
Patrocinador
Investigadores
- Investigador principal: Clodagh M Ryan, Toronto General Hospital
Fechas de registro del estudio
Fechas importantes del estudio
Inicio del estudio
Finalización primaria (Anticipado)
Finalización del estudio (Anticipado)
Fechas de registro del estudio
Enviado por primera vez
Primero enviado que cumplió con los criterios de control de calidad
Publicado por primera vez (Estimar)
Actualizaciones de registros de estudio
Última actualización publicada (Estimar)
Última actualización enviada que cumplió con los criterios de control de calidad
Última verificación
Más información
Términos relacionados con este estudio
Palabras clave
Términos MeSH relevantes adicionales
Otros números de identificación del estudio
- 09-0831-BE
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