Stroke Tutorials Flashcards
What % of strokes occur in those >65?
75%
What % of people will die in the first year after a stroke?
1/3rd
What % of people will remain dependent on others after surviving a stroke?
50%
What is the WHO definition of stroke?
Rapidly developing clinical signs of focal (or global) disturbance of cerebral function, with symptoms lasting =>24h or leading to death with no apparent cause other than vascular
Define TIA
Brief episode of neurological dysfunction caused by focal brain or retinal ischaemia with clinical symptoms typically lasting less than 1h and without evidence of acute infarction
In which period of time do the majority of TIAs resolve in?
60 minutes
How does the length of a TIA correlate with symptom resolution?
<15% chance of complete resolution of symptoms if TIA lasts >1h
What are the two major categories of stroke? What is their prevalence?
Ischaemic - 85%
Haemorrhagic - 15%
- 70% primary ICH
- 30% secondary haemorrhage, e.g. SAH, AVM
What sort of things may cause a stroke?
Intracranial atherosclerosis Carotid plaque with atherogenic emboli Aortic arch plaque Cardiogenic emboli AF Valve disease Penetrating artery disease (lacunar stroke) Flow reducing carotid stenosis Carotid dissection Left ventricle thrombi
Where do the carotids mostly supply?
Most of the hemispheres and cortical deep white matter
Where does the vertebro-basilar system supply?
Brainstem, cerebellum, occipital lobe
What are the functions of the temporal lobe?
Primary auditory receptive area
Comprehension of speech (dominant) - Wernicke’s area
Visual, auditory and olfactory perception
Important role in learning, memory and emotions
What are the functions of the frontal lobe?
High level cognitive functions, e.g. abstraction, concentration reasoning Memory Control of voluntary eye movement Motor control of speech in dominant hemisphere Motor cortex Urinary continence Emotion and personality Broca's area
What are the functions of the parietal lobe?
Sensory cortex Sensation (touch, pressure, position) Awareness of parts of body Spatial orientation + visuospatial information (non-dominant hemisphere) Ability to perform learned motor tasks
What are the functions of the occipital lobe?
Primary visual cortex
Visual perception
Involuntary eye movement
What is the main function of the cerebellum?
Balance and coordination
What are the functions of the brainstem?
Swallowing, breathing, heartbeat, wakefulness
What is Broca’s area essential for?
Language pronunciation, production and articulation
Why are small strokes in the deep white matter so bad?
All the fibres are packed closely together so small strokes can result in large deficits
What is the brainstem composed of?
Midbrain, pons, medulla
What are some clinical presentations of stroke?
Sudden onset loss of function:
- Motor (clumsy/weak)
- Sensory
- Speech (dysarthria/dysphagia)
- Neglect/visuospatial problems
- Vision (loss in one eye (amaurosis fugax) or hemianopia)
- Gaze palsy
Ataxia, vertigo, incoordination, nystagmus
What are some key things to remember about the symptoms of stroke?
Symptoms come on rapidly
Symptoms depend on area of brain affected
Abnormal movements after stroke are unusual
Positive visual phenomena probably = migraine
Severe headache after stroke unusual
What is the most commonly used clinical classification of strokes?
Oxford community stroke project classification
What causes a TACS?
Total anterior circulation syndrome
Caused by blockage/bleed from main artery to one of the hemispheres
What symptoms do you get in TACS?
3/3 of:
- Complete hemiparesis/numbness
- Hemianopia (loss of vision on one side)
- Loss of awareness on one side (inattention) if non-dominant OR dysphagia if dominant
What causes a PACS?
Partial anterior circulation syndrome
Caused by bleed/blockage to a branch of a main artery
What are the symptoms of a PACS?
2/3 of TACS criteria or
- one higher cortical deficit, e.g. inattention or dysphagia
or
- monoparesis
What causes a LACS?
Lacunar syndrome
Blockage/bleed from a small perforating artery
Tends to affect movement/sensation pathways
What are the symptoms of a LACS?
Weakness/numbness of:
- face + arm + leg OR
- face + arm OR
- arm + leg
May have dysarthria, ataxic hemiparesis but no affect on higher function (i.e. no dysphagia, inattention, hemianopia)
What causes POCS?
Posterior circulation syndrome
Bleed/blockage in any posterior artery
What symptoms occur in POCS?
Combination of symptoms including:
- Loss of balance/coordination
- Vertigo
- Double vision
- Dysarthria
- Visual loss (hemianopia)
What does basilar artery occlusion lead to?
Ischaemia in pons
What sort of signs/symptoms do you see in basilar artery occlusion?
Predominantly motor/oculomotor signs/symptoms which are bilateral by asymmetrical
May see alteration in conscious level, may present as unresponsive
Which type of stroke has the highest mortality?
TACS
Which type of stroke has the highest recurrence rate?
POCS/PACS
What are non-modifiable risk factors for stroke?
Prev stroke
Age
Male
FH
What are modifiable risk factors for stroke?
Smoking COCP HTN Obesity Sedentary lifestyle and poor diet Hyperlipidaemia (high LDL) Cocaine use DM AF Alcohol excess
If someone has cranial nerve deficits and a stroke what type of stroke is it they’ve likely had?
Brainstem stroke
What is the most important RF for stroke?
HTN - chronic HTN exacerbates atheroma + increases involvement of smaller distal arteries
How do DM, hyperlipidaemia and smoking contribute to risk of stroke?
DM, HTN, cigarette smoke contribute to LDL-C deposition in arterial walls
By how much does having AF increase your chance of having a stroke?
5x
Which two drugs can reduce the risk of stroke in those with AF?
DOACs and warfarin
Name some DOACs
Apixiban
Rivaroxiban
Edoxaban
Dabigatran
What are some stroke mimics?
7Ss - Seizures Syncope (hypotension) Sugar (hypo/hyper) Sepsis (+ prev stroke) Severe migraine Space occupying lesions Si-chological
Others - vestibular disorders, demyelination, transient global amnesia, mononeuropathy
What is the most common stroke mimic?
Migraine
What things may point towards migraine as opposed to stroke?
Younger age Positive, spreading symptoms (flashing lights, somatosensory (pain, paraesthesia), motor (jerking)) may be followed by negative symptoms LOC v. rare Assoc. headache, NV, photophobia Usually lasting 20-30m
What causes a migraine aura?
Cortical spreading depression
What can a migraine aura take the form of?
Visual disturbance - scintillating scotomata, geometric (zig-zag patterns), kaleidoscope, running water etc.
can include sensory, motor or speech disturbance
Headache onset can be >1h after the end of aura or no headache
What is a acephalgic migraine?
Migraine with aura without headache
How might functional disorders/anxiety mimic a stroke?
Isolated sensory symptoms common Mostly occur suddenly/on waking Often get dissociative symptoms Often non-dominant side Tends to be INCONSISTENCY in symptoms
What test can you use to try and identify a functional disorder?
Hoover’s sign or abductor sign
What do you tend to see in acute vestibular syndrome?
Acute onset, v. disabling
Nystagmus - unidirectional
Vomiting
MRI may be helpful
What symptoms may point towards a seizure as opposed to a stroke?
Tongue biting Incontinence Muscle pain Disorientation Headache Post-ictal symptoms may last days LOC/amnesia common Progresses v. quickly, lasts up to 5m
What symptoms may point towards a syncope as opposed to a stroke?
Presyncope (light headed) Vision darkens/muffles Loss of awareness Transient LOC with loss of postural tone + rapid recovery No focal symptoms V. rapid and rapid recovery
What is transient global amnesia?
Temporary loss of anterograde episodic memory
Usually lasts several hours and usually able to fill in old memories and create new ones again
In what group of people does transient global amnesia tend to occur?
Those over 50Y
Those with vascular RFs
