GMED3009- CVA (stoke) Flashcards
What are the 4 regions of the brain
1) cerebrum = interprets sensory input, controls skeletal muscle activity, intellectual, emotions and memory.
2) diencephalon = regulates the autonomic nervous and endocrine systems
3) brain stem = serves as a conduction pathway and regulates skeletal muscles
4) cerebellum = processes information related to balance, posture and coordinated muscle movement
Definition of stoke
supply of blood to the brain is suddenly disrupted. Blood is carried to the brain by blood vessels. Blood may stop moving through an artery because the artery is blocked by a blood clot or plaque, or because the artery breaks or bursts”
Risk factors associated with stoke
- Modifiable risks
o Hypertension
o Heart disease
o Diabetes mellitus
o Blood cholesterol levels
o Smoking
o Substance abuse - Non-modifiable risks
o Age
o Race
o Sex
o Ethnicity
o Heredity
Pathophysiology of stoke
- The brain receives approximately 20% of total cardiac output each minute and accounts for 20% of the body’s oxygen consumption
- Blood flow to the cerebral vessels is self-regulated (autoregulation)
- The self regulation is not effective when systemic blood pressure falls below 50 mmHg or rises above 160mmHg
- Pathophysiological changes at cellular level take place in 4 to 5 minutes when blood flow to and oxygenation of cerebral neurons are decreased or interrupted.
- Cellular metabolism ceases as glucose, glycogen, and adenosine triphosphate (ATP) are depleted and the sodium-potassium pump fails.
- Cells and Cerebral blood vessels walls swell as sodium draws water into the cell, further decreasing blood flow.
- Vasospasm and blood viscosity also impede blood flow.
- Severe prolonged ischaemia leads to cellular death.
What are te 2 types of stoke?
1) Hemorrhagic- bleed of the brain
2) Ischemic- blockage of the brain
What are the types of hemorrhagic stoke?
- leading cause is hyertension, originates from a weak spot in a blood vessel wall (cerebral aneruysm) or other malformation in or around the brain
1) ) Intracerebral Haemorrhage (ICH)
▪ The blood that leaks into the brain results in a sudden increase in pressure that can damage the surrounding brain cells.
▪ If the amount of blood increases rapidly, the sudden and extreme build up in pressure can lead to unconsciousness or death.
2) Subarachnoid Haemorrhage (SAH)
▪ Bleeding between the inner and middle layer of tissue covering the brain (subarachnoid space), ventricles and spine.
▪ Secondary to trauma, cerebral aneurysmal rupture or rupture of a arteriovenous malformation (AVM).
▪ SAH is secondary to AVM or aneurismal rupture. Neurosurgical consultation should be sought
3) Cerebral aneurysm
▪ A brain aneurysm is a weak bulging spot on the wall of a brain artery very much like a thin balloon or weak spot on an inner tube.
▪ Aneurysms form from wear and tear on the arteries, and sometimes from injury, infection or an inherited tendency
What are the types of ischemic
- caused by obstruction of an artery leading to or in the brain, preventing oxygenated blood and nutrients from reaching parts of the brain that the artery feeds.
1) Thrombotic Ischemic stoke (obstructs)
▪ There are two types of thrombotic stroke:
▪ Large vessel thrombosis, the most common form of thrombotic stroke, occurs in the brain’s larger arteries.
▪ Small vessel disease (lacunar infarction – deep brain infarct) occurs when blood flow is blocked to a very small arterial vessel.
2) Embolic ischemic stroke (breaks free and travel)
▪ A blood clot that forms in one area of the body and travels through the bloodstream to another where it may lodge is called an embolus.
▪ During AF, the quivering atria are very inefficient at pumping blood to the ventricle. As a result, some blood remains in the atrium too long and clots can begin to form in this stagnant blood.
▪ If a clot (embolus) breaks loose and is carried into the blood stream, it can travel anywhere in your body.
▪ There it eventually reaches a blood vessel small enough to block its passage.
▪ Emboli can be fat globules, air bubbles or, bits and pieces of atherosclerotic plaque, such as lipid debris, that have detached from the artery wall or, most commonly, fragments of thrombus from a cardiac source.
3) Transient Ischemic Attack or TIA
▪ The current definition of TIA is that symptoms resolve within 24 hours although there are suggestions to change to <1 hour).
▪ TIA Is a transient obstruction to blood flow where no significant damage is detected on CT or MRI
▪ Should no longer be referred to as a ‘mini stroke’. It is in fact a direct warning that a major stroke will potentially occur.
▪ Not possible to tell the difference between stroke and TIA initially – can only be more accurately confirmed by MRI.
▪ Important to get to medical attention urgently!!
▪ Expedited review, investigations and management are still required, either as inpatient or outpatient.
Signs and symtoms of TIA a stoke
● Hemiparesis, monoparesis, or (rarely) quadriparesis
● Hemisensory deficits
● Monocular or binocular visual loss
● Visual field deficits
● Diplopia
● Dysarthria
● Facial droop
● Ataxia
● Vertigo (rarely in isolation)
● Aphasia
● Sudden decrease in the level of consciousness
Clinical assessment of a patient present with a stoke
- Distinguish stroke from stroke mimics (Seizure , infection, brain tumour)
- Determine and document for future comparison the degree of deficit
- Localize the lesion
- Identify comorbidities
- Identify conditions that may influence treatment decisions (eg, trauma, active bleeding, active infection)
USE FAST
Head, neck, cardiac and extremities examination
AF commonly associated with people with stoke
Neurological examination
Routine investigations performed for a pt with stoke
● CT
● MRI
● Blood Test (Cardiac, lipids, pregnancy, Toxicology)
● Doppler U/S
● Angiography
● Coagulation blood tests
hemorrhagic shock typical symptoms
● Weakness or paresis that may affect a single extremity, one half of the body, or all 4 extremities
● Facial droop
● Monocular or binocular blindness
● Blurred vision or visual field deficits
● Dysarthria and trouble understanding speech
● Vertigo or ataxia
● Aphasia
symptoms of Subarachnoid hemorrhage
▪ Sudden onset of severe headache
▪ Signs of meningismus with nuchal rigidity
▪ Photophobia and pain with eye movements
▪ Nausea and vomiting
▪ Syncope - Prolonged
routine clinical nursing care and interventions for patient with stoke?
Nursing Priorities
* Promote adequate cerebral perfusion and oxygenation.
* Prevent/minimize complications and permanent disabilities.
* Assist patient to gain independence in ADLs.
* Support coping process and integration of changes into self-concept.
* Provide information about disease process/prognosis and treatment/rehabilitation
Goals of pt and family-
improving mobility and preventing deformaties
esablishing an exercise program
preparing for ambulation
preventing shoulder pain
enhancing self care
assissting with nutrition
attaining bowel and bladder control
improving communication
maintaining skin integrity
Complications associcated with stroke
Dysphagia
Pneumonia
pharmological treatment
heparin- anticoagulant
clopidogrel- antiplatelete
Apixaban- anticoagulant
dabigataran- anticoagulant
rivaroxaban- atticoagulation
