Strokes Flashcards
Causes of stroke.
2 major categories - 3 subdivisions of one.
1) Ischaemic stroke
1a) small vessel occlusion, thrombosis etc
1b) cardiac embolism (AF etc)
1c) atherothromboembolism (from carotids etc)
1d) sudden BP drop - damage to watershed zones, (sepsis etc), vasculitis, then rare stuff - all more common in younger people
2) haemorrhagic stroke (high BP, trauma, aneurysm rupture, anti coagulation, thrombolysis etc
Signs of a cerebral infarct (50% of infarcts)
Sudden onset (may progress over hours)
Contralateral sensory loss
Hemipleglia - initially flaccid limbs (floppy) become spastic (UMN)
Dysphagia (brocas area)
Homonymous hemianopia
Viso-spatial defect
Depends on the artery territory which has been occluded
Signs of brainstem infarct (25%)
Sudden onset Quadriplegia Disturbances of gaze/vision Locked in syndrome Etc
Signs of lacunar infarct (25%)
Stroke in basal ganglia, internal capsule, thalamus, pons
5 possible syndromes
1) ataxic hemiparesis
2) pure motor
3) pure sensory
4) sensorimotor
5) dysarthria / clumsy hand
Cognition/GCS normal - apart from when thalamus is affected
Differentiate between ischaemic stroke and haemorrhagic stroke?
In the CT scan
Signs: bleeds - meningism, severe headache, coma in hours
Ischaemic - carotid bruit, AF, past TIA, IHD
Signs are unreliable
Immediate stroke management
CT head, if Ischaemic then alteplase if within 4.5 hours and aspirin 300mg
Secondary prevention of strokes
Ie after a stroke - preventing any more
Clopidogrel
Warfarin if in AF
ECG
Carotid Doppler
Fibrinolytic drugs
Alteplase, streptokinase
(For ischaemic stroke in 4.5hr, STEMI (but PCI better), massive PE)
Catalyse plasminogen to plasmin which dissolves clots
Scoring system used to predict stroke risk after TIA?
ABCD2
Age - 60+ (1)
Blood pressure above 140/90 (1)
Clinical features (unilateral weakness - 2points, speech disturbance no weakness - 1 point)
Duration of symptoms (1hours + =2points, 10-59 mins = 1 point)
Diabetes (1)
4/7+ = referral
Tool used to assess stroke risk when in atrial fibrillation
CHA2DS2-VASc
C - congestive heart failure +1 H - hypertension over 140/90 or on BP drugs +1 A - age (75+ = +2) D - diabetes = +1 S - previous stroke or TIA = +2 V - Vascular disease (MI etc) +1 A - age (65-74) = +1 S - sex - female +1
Carotid/vertebral artery dissection
20% of strokes under 40
often after neck trauma
- blood leaks through the subintimal wall and makes a false lumen. the release of tissue thromboplastin causes thrombosis within the true lumen which can lead to an embolus and stroke
neck/face pain is the helpful part in the history
carotid dissection can cause horners syndrome/affect lower cranial nerves
Risk factors for stroke
Hypertension Isc/Hae Smoking Isc>Hae Sedentary lifestyle Isc Excessive alcohol Isc/Hae High cholesterol Isc Atrial fibrillation Isc >>Hae Obesity both probs Diabetes Isc Severe carotid stenosis Isc Sleep apnoea Isc
Isc -Ischaemic stroke risk increase
Hae - haemorrage stroke risk increase
anterior circulation vessels- what are they?
Internal carotid
middle cerebral
anterior cerebral
opthalmic arteries
Middle cerebral artery occlusion - predicted effects if severe
Contralateral hemiplegia facial weakness hemisensory loss neglect syndromes (can't see something in one side etc) eye deviation towards affected side aphasia - if in dominant hemisphere hemianopia
infarcted brain tissue can swell - and cause coning - decompressive craniectomy required
if just branches of the MCA are affected then only some of these symptoms will appear
Brainstem infarcts
What happens based on the anatomical structures affected? Name structures with symptoms if damaged
corticospinal tracts - hemi/tetraparesis
Medial lemiscus/spinothalamic tracts - sensory loss
Oculomotor system - diplopia
5th nerve nuclei - facial numbness
7th nerve nuclei - facial weakness
8th nerve/vestibular - nystagmus, vertigo
9th/10th nerve - dysphagia, dysarthria
brainstem/cerebellar connections - dysarthria, ataxia, hiccups, vomiting
sympathetic fibres - horner syndrome
reticular formation - Coma, \/GCS
