ELM 18: Stroke ` Flashcards
Definition of stroke
Reduced blood flow and oxygen to the brain
Causes of stroke
Brain artery blocks or bleeds
Poor circulation
Heart failure
Drowning
Low O2 at birth
Risk factors of stroke
Atherosclerosis
Age
Diabetes
Ethnic origin
Family history
Heart disease
High BP
High cholesterol
Obesity
Smoking
Symptoms of stroke
Sudden headache
Unexplained dizziness or unsteadiness
Sudden speech difficulty
Sudden dimness or loss of vision
Sudden weakness or numbness on one side of body
Two types of stroke
Ischaemic stroke = Vessel gets blocked
Haemorrhagic stroke = Vessel bursts
Causes of ischaemic stroke
50% = Atherothromboembolism cerebral arterial supply
20% = embolism from heart 25% = intracranial small vessel disease
5% = rare causes
Difference in effect on cells in the immediate vs surrounding area when ischaemic stroke occurs
Cells in immediate area die and are beyond rescue
Cells in surrounding area are under threat but can be rescued
What is the core and penumbra?
Core = dead tissue
Penumbra = vulnerable tissue
What are the three types of ‘killers’ in the brain
Neurotransmitters (Glutamate)
Ions (calcium and sodium)
Free radicals (abnormal oxygen molecules)
Process of excitotoxicity
- Ischaemia causes decreased oxygen in brain and membrane depolarisation of neurons
- Glutamate release and calcium influx
- Causes calcium overload eventually causing free radical formation
What is reperfusion injury
Restoration of blood flow to an area of brain that was previously ischaemic
Caused by clot lysis or dislodgement
Causes inflammation and oxidative stress
Some disabilities caused by stroke
Paralysis/motor control
Sensory disturbances like pain
Language problems
Memory impairment
Depression or anxiety
3 reparative mechanisms
Plasticity
Neurogenesis
Angiogenesis
