Stroke Flashcards
How much of the brain’s blood supply does the brain consume?
15-20%
How much does the brain weigh?
2%
What materials does fresh blood bring IN to the brain?
Oxygen, carbohydrates, amino acids, fats, hormones, and vitamins go in.
What materials does fresh blood bring OUT of the brain?
Carbon dioxide, ammonia, lactate, and hormones.
What is the Circle of Willis?
It is a collection of arteries that supplies blood to the brain and surrounding structures.
The Circle of Willis is composed of which arteries?
Internal Carotid Arteries
Anterior Cerebral Arteries
Posterior Cerebral Arteries
What is a Stroke?
It is a medical condition in which an abnormality of the vascular supply causes damage to the CNS.
How does the WHO define a Stroke?
It is a neurological deficit of cerebrovascular cause that persists beyond 24 hours or is interrupted by death within 24 hours.
What are the two main types of strokes?
Ischemic and Hemorrhagic.
What are the clinical symptoms of a Stroke?
Weakness in the face/limbs. Numbness Aphasia or Dysarthria Vision loss Headache (more common with hemorrhagic stroke).
What are the rare clinical symptoms of a Stroke?
Loss of consciousness
Pain
Abnormal movement
What is an Ischemic Stroke?
Blockage of arterial blood vessels.
What are the two types of Ischemic Stroke?
Thrombosis and Embolism.
What is Thrombosis?
This is an obstruction of a blood vessel by a local blood clot.
What is Embolism?
This is an obstruction due to an embolus (travelling particle or debris in the bloodstream) from elsewhere in the body.
What happens during an Ischemic Stroke?
The brain tissue ceases to function is it is deprived of oxygen for more than 60-90 seconds.
After 3 hours of Ischemia the brain will suffer irreversible damage.
The body is not good at generating ATP in the absence of oxygen (lactate -> lactic acid -> acidosis).
Leads to failure of energy-dependent processes in brain cells (e.g. ion pumping).
This leads to apoptosis.
What is an Infarction?
This is a tissue death (necrosis) caused by lack of blood supply to the affected area.
What is a Hemorrhagic Stroke?
This is bleeding in or around the brain’s membranes, usually caused by a rupture of a blood vessel or abnormal capsular structure.
What are the 4 types of Hemorrhagic Strokes?
Epidural
Subdural
Sub-Arachnoid
Intracerebral
What is an Epidural Stroke?
Occurs between the skull and dura matter.
What is a Subdural Stroke?
Occurs between the dura matter and arachnoid space .
What is a Sub-Arachnoid Stroke?
Occurs between the arachnoid space and pia matter.
What is an Intracerebral Stroke?
This bleeding within the brain itself.
Either from the brain tisse (intraparenchymal hemorrhage) or from brain’s ventricular system (intraventricular hemorrhage).
What are the symptoms for a Hemorrhagic Stroke?
Severe headache
Dizziness
Seizures
Vomiting
How can you prevent a Stroke?
Blood pressure medication
Anticoagulation drugs
Surgery
Diet
What are the risk factors associated with a Stroke?
Tobacco smoking High blood cholesterol Diabetes mellitus Lipids Atrial fibrillation (abnormal heart rhythm) Obesity Age > 75
What is the biggest and most important risk factor for a Stroke?
Hypertension (high blood pressure).
Hypertension accounts for what risk rate?
35-50%
How are Strokes treated?
Stroke rehabilitation - includes physical therapists, occupational therapists, speech-language pathologists.
This is a treatment that intends to try and recover lost function.
What causes Cerebral Edema?
The release of osmotically active substances from necrotic brain tissue.
Axons will swell which causes the unravelling of the myelin sheath.
There is a neuroinflammatory response to release substances, which forms a glial scar around the infarct.
