Stroke: Presentation and Investigation Flashcards
Stroke
Neurological deficit causing loss of function:
- of sudden onset
- lasting more than 24 hrs
- of vascular origin
Transient ischaemic attack
Lasts less than 24 hrs
Symptoms of stroke
- Loss of power
- Loss of sensation
- Loss of speech
- Loss of vision
- Loss of coordination
What may included in the history of the complaint?
- Time of onset
- Witnesses
- Headache/ vomting/ neck stiffness/ photophobia
- Loss of consciousness
- Fit
- Incontinence
What may be found on neurological examination?
- Motor: clumsy or weak limbs
- Sensory: loss of feeling
- Speech: dysarthria/ dysphasia
- Neglect/ visuospatial problems
- Vision: loss in one eye/hemianopia
- Gaze palsy
- Ataxia/vertigo/incoordination/nystagmus
What is a stroke?
Damage to part if the brain due to blockage of a blood vessel by thrombus or embolus or due to haemorrhage from rupture of a blood vessel
What are the 2 kinds of stroke?
- Ischaemic
- Haemorrhagic
What does the carotid system supply?
Most of the hemispheres and cortical deep white matter
What does the vertebra-basilar system supply?
The brain stem, cerebellum and occipital lobes
Motor cortex
Movement
Sensory cortex
Pain, heat and other sensations
Parietal lobe
Comprehension of language
Temporal lobe
Hearing
Occipital lobe
Primary visual area
Wernicke’s area
Speech comprehension
Cerebellum
Coordination
Brainstem
Swallowing, breathing, heartbeat, wakefulness centre and other involuntary functions
Temporal lobe
Intellectual and emotional functions
Frontal lobe
- Smell
- Judgement, foresight and voluntary movement
Broca’s area
Speech
Why does a small stroke in the pons or near the centre of the brain result in major deficit?
The fibres are packed close together
Causes of stroke
- Blockage of a vessel with thrombus or clot
- Disease of vessel wall
- Disturbance of normal properties of blood
- Rupture of vessel wall
What are most strokes caused by?
Infarction
What can cause ischaemic stroke?
- Large artery atheroscleorosis
- Cardioembolic
- Small artery occlusion
- Undetermined/cryptogenic
- Atrial dissection
- Venous sinus thrombosis
What can cause haemorrhagic stroke?
- Primary intracerebral haemorrhage
- Subarachnoid haemorrhage
- Arteriovenous malformation
What happens in ischaemic stroke?
Clot stops blood supply to an area of the brain
What happens in haemorrhagic stroke?
Haemorrhage/ blood leaks into brain tissue
What is the most common cause of cardioembolic stroke/
Atrial fibrillation
What is another name for small vessel stroke?
Lacunar
What can cause carotid dissection?
Idiopathic or trauma
What must you determine when investigating what part of the brain is affected?
- Left or right
- Carotid territory or vertebrobasilar territory
- Cerebral hemispheres or brainstem
- Cortex or deep white matter
- Blood vessels involved
Why do you need to know where a stroke is located?
- Confirms the diagnosis
- Allows better selection of imaging
- Gives an indication of cause
- Gives an indication of prognosis
Stroke subtypes
- TACS: total anterior circulation stroke
- PACS: partial anterior circulation stroke
- LACS: lacunar stroke
- POCS: posterior circulation stroke
What type of lesion would cause unilateral field loss?
Optic nerve compression
What type of lesion would cause bitemporal hemianopia?
Chiasmal compression from pituitary tumour
What type of lesion would cause homonymous hemianopia?
Left cerebrovascular event
What is usually the cause of TACS?
Occlusion of proximal MCA or ICA
What does TACS cause?
- Weakness
- Sensory deficit
- Homonymous hemianopia (loss of vision)
- Higher cerebral dysfunction (dysphasia, dysphagia)
What causes PACS?
More restricted cortical infarcts by occlusion of branches of MCA
How does TACS present?
2 of 3 of TACS criteria or restricted motor/ sensory deficit
What are the types of LACS?
- Pure motor
- Purre sensory
- Sensorimotor
- Ataxix hemiparesis
Pure motor LACS.
Complete or incomplete weakness of 1 side, involving the whole of 2 or 3 body areas
Pure sensory LACS
Sensory symptoms and/or signs
Sensorimotor LACS
Combination of pure motor and pure sensory
Ataxix hemiparesis LACS
- Hemiparesis and ipsilateral cerebellar ataxia.
- Small infarcts in basal ganglia or pons
- Intrinsic disease of single basal perforating artery
What do POCS affect?
Brainstem, cerebellar or occipital lobes
What may the variable, frequently complex presentation of POCS include?
- Bilateral motor/sensory deficit
- Disordered conjugate eye movement
- Isolated homonymous hemianopia
- Ipsilateral cranial nerve palsy with contralateral motor/ sensory deficit
- Coma
- Disordered breathing
- Tinnitus
- Vertigo
- Horner’s
Strokes subtype by mortality @1 yr (highest at top)
- TACS
- POCS
- PACS
- LACS
Strokes subrtype by recurrence rate @ 1 yr(highest at top)
- POCS
- PACS
- LACS
- TACS
What are the modifiable risk factors for stroke?
- Hypertension
- Atrial fibrillation
What are the non-modifiable risk factors for stroke?
- Age
- Race
- Family history
What are the investigations for stroke?
- FBC
- Lipids
- ECG
- CT
- MRI
- Carotid Doppler
- Sometimes an ECHO can identify clots in the heart
What are the advantages of CT?
- Quick
- Shows up blood
What are the advantages of MRI?
Shows up ischaemic stroke better than CT
What are the disadvantages of MRI?
- Takes up to 30 minutes
- Claustrophobic
