Neurology - Stroke Flashcards
What is a stroke defined as
acute focal neurological deficit resulting form cerebrovascular disease and lasting more than 24h or causing earlier death
What is a store
it is the death of brain tissue from hypoxia due to no local cerebral blood flow
What can result in no local cerebral blood flow
infarction of tissue
hemorrhage into the brain tissue
What is it called if there is temporary ischemia
transient ischemic attack
What are the 4 big symptoms
facial drooping
arm weakness
speech difficulty
time
What is a transient ischemic attack
localized loss of brain function due to an ischemic event not a hemorrhage
full recovery within 24 hours but most recover in 30 minutes
results in higher risk of proper stroke
What are risk factors for stroke
HYPERTENSION SMOKING alcohol ISCHAEMIC HEART DISEASE atrial fibrillation diabetes mellitus
How is hypertension such a big risk?
if the diastolic is >110mg then there is a 15x risk compared to diastolic <80mmHg
even borderline hypertension has a risk
What are the different types of stroke
ischemic stroke
intracranial bleed
embolic stroke
What causes an inter cranial bleed usually
aneurysm rupture
What can cause an embolic stroke
embolism coming from left side of the heart
atheroma of cerebral vessels
What can cause embolism from the LHS of the heart
atrial fibrillation
heart valve disease
recent MI
What can cause an atheroma of a cerebral vessels
carotid bifurcation
internal carotid artery
vertebral artery
What are less common causes of stroke
venous thrombosis
borderline infarction
vasculitis
What can cause venous thrombosis
oral contraceptive use
polycythemia
thrombophillia
How do we prevent stroke
reduce risk factors anti platelet action anticoagulants carotid endarterectomy preventative neurosurgery
What risk factors can we reduce
smoking
diabetes
control hypertension
How is anti platelet action used for stroke prevention
used for secondary prevention only
aspirin
dipyridamole
clopidogrel
Why are anticoagulants used for prevention
embolic risk - usually those with AF, LV thrombus
What are the common anticoagulants usually given for prevention
warfarin, apixaban
What are the preventative neurosurgery
aneurysm clips
AV malformation correction
What do we need to figure out in investigation of stroke
need to differentiate cause - is it infarct, bleed or subarachnoid hemorrhage
What is used for investigation of stroke
CT scan
MRI
DSA
assess risk factors
What are advantages and disadvantages of CT scan
rapid, easy access
poor for ischemic stroke
What are advantages and disadvantages of MRI scan
difficult to obtain quickly
better at visualizing early changes of damage
MRA is the best investigation for visualizing the brain circulation
What is DSA used
if MRA not available
How do we assess risk factors in investigations
carotid ultrasound cardiac ultrasound (LV thrombus) ECG (arythmias) blood pressure diabetes screen thrombophilia screen (young px)
What is the effect of a stroke
loss of functional brain tissue
gradual or rapid loss of function
inflammation in tissues around the infart/bleed
Why i sheer loss of functional brain tissue
due to immediate nerve cell death
nerve cell ischemia in penumbra around infarction will result in death if not protected
What are complications of stroke
motor function loss dysphonia swallowing sensory loss cognitive impairment
How does motor function loss present
can be cranial nerve or somatic (opposite side!)
autonomic is effected in brain stem lesions
What are complications of the loss of swallowing in complications
aspiration of food and saliva
pneumonia and death
How may sensory loss present
cranial nerve or somatic may be effected (opposite side)
body perception may be different - neglect or phantom limbs
How will the cognitive impairment present
appreciation - special sensation
processing
memory impairment
emotional lability and depression
How does the processing present
understanding of information
speech and language - dysphasia, dyslexia, dysgraphia, dyscalculia
What is the management of stroke in the acute phase
limit damage
reduce future risk
What is the management of stroke in the chronic phase
rehabilitation
reduce future risk
How do we limit damage in acute phase treatment
penumbra region 0 survivable ischaemia
improve blood flow/oxygenation
normoglycemia
How do we try to save the penumbra region in acute phase treatment
using calcium channel blockers (nimodipine)
How do we improve blood flow/oxygenation
thrombolysis possible within 3 hours (alteplase)
maintain perfusion pressure to brain tissue
When can we remove the hematoma
in sub arachnoid hemorrhage only
How do we prevent future risk
aspirin 300mg daily
anticoagulation if indicated (delay 2 weeksO
When are anticoagulants indicated
atrial fibrillation
LV thrombus
What is chronic phase treatment
nursing and rehabilitation - immobility support, speech and language therapy, occupational therapy
How do we give immobility support
prevention of bed sores
physiotherapy to prevent contractures
Why do we give speech and language therapy
communications
swallowing and eating
What are dental aspects of stroke
impaired mobility and dexterity communication difficulties risk of cardiac emergency loss of protective reflexes loss of sensory information stroke pain
What is the relevance of sensory information
difficulty in adaption to new oral environment
What is the risk fo cardiac emergencies
MI, further stroke
