28. Stroke Flashcards
What is a stroke?
A condition characterised by rapidly progressive clinical symptoms and signs of focal, and at times global, loss of cerebral function lasting more than 24 hours or leading to death with no apparent cause other than that of vascular origin
What are the different types of stroke and how common are they?
Ischaemic stroke: 70-80% - result of an obstruction of a cerebral blood vessel
Haemorrhagic stroke: 20-30% - occurs when a weakened blood vessel ruptures in the brain
What is the main cause of a haemorrhagic stroke?
Haemorrhagic stroke occurs as a intracerebral haemorrhage (i.e. an intracranial bleed occurring in the brain tissue or in the ventricles)
This most commonly arises as a result of hypertension which causes micro-aneurysms formed on the end of small blood vessels to rupture
What are the complications of ICH?
ASk mimi
How is ICH managed?
Establish the cause via imaging/angiography/clotting and platelet function
Stop aspirin or warfarin administration
Treat the complications via surgery - minimally invasive surgery known as Buhrr holes to break apart the clot
Treat the risk factors e.g. blood pressure
Rehabilitation of the patient
What causes ischaemic stroke?
Arteriosclerosis
Atherosclerosis
Carotid dissection
Cardiac embolism e.g. AF
These result in a lack of oxygen supply to certain regions of the brain and this results in damage and death of the neurones
How does AF cause ischaemic stroke?
Due to stasis in the left atrial appendage increases the risk of blood clot formation - this needs to be obliterated
What are the risk factors for stroke?
Increasing age (10% happens in under 50s) Male sex Race other than white Smoking Increased weight Inactivity High alcohol consumption Hypertension Hypercholestrolaemia Diabetes Vascular disease Atrial fibrillation Family history
Why are statins administered for stroke prevention?
1mm/L drop in LDL cholesterol results in a 15% decrease in the risk of an ischaemic stroke - reduces the risk immensely
What investigations can be used to explore the level of stroke that is present?
Imaging - CT and MRI Bloods - FBC, ESR, fasting of glucose, cholesterol Carotid doppler ECG ECHO
What deficit will mainly occur from a left hemisphere stroke?
Reading and language deficits
Give the pyramidal pathway and what is the function of this?
Primary motor cortex to the Internal capsule to the Cerebral peduncles to the Decussation of the pyramids to the Descending corticospinal tracts
NB. there will be a decussation at the level of the medulla
These are efferents which will carry action potentials to the muscles of the limbs
What is a lacuna stroke and what is the most common cause
A lacuna stroke is the most common type of stroke - results from the occlusion of small penetrating arteries travelling to the deep regions of the brain
Main cause is perforator disease - damage to the small perforating blood vessels that supply blood to the basal ganglia
How is stroke treated?
Consider thrombolysis Anti-platelet therapy Address risk factors Treat complications Advice and education
What is thrombolysis and how is it administered?
This is currently the best treatment option for stroke - this is the dissolution of a blood clot induced artificially via the infusion of an enzyme into the blood (thrombolytic drugs are administered)
Time is imperative for this to be successful
