Stroke - Presentation and Investigation Flashcards
What is a stroke?
Sudden loss of neurological function, that lasts more than 24 hours and is of vascular origin. Loss of power, loss of vision, loss of speech (important to differentiate from stroke).
How does a stroke differ from TIA?
TIA is less than 24 hours. TIA event symptoms will normally last less than 10 mins.
What are the stroke symptoms?
Loss of power
Loss of sensation (arm feels dead and cold)
Loss of speech (loss of comprehension of speech, or fluent speech)
Loss of vision (complete loss, or double vision in brain stem stroke)
Loss of coordination (in brain stem stroke)
What would you find on history/examination of a stroke patient?
Motor (clumsy or weak limb) Sensory (loss of feeling) Speech - dysathria/dysphasia Neglect/visuospatial problems Gaze palsy Ataxia/vertigo/incoordination/nystagmus
What are the most important symptoms in a stroke?
Loss of some function.
What is a gaze palsy?
Double vision (inability to move both eyes in the same direction).
What is ataxia?
Lack of coordination of voluntary movements.
What is dysathria?
Difficult or unclear articulation of speech.
What is dysphasia?
Deficiency in the generation of speech.
Why do people develop a stroke?
Damage to part of the brain due to blockage of the blood vessel by thrombus or embolus. Or due to haemorrhage from rupture of a blood vessel.
What is a penumbra?
Ischaemic area that is not dead as it still gets some oxygen from surrounding vessels but not quite enough - ‘sleeping’.
What may cause a vessel to rupture causing haemorrhage?
Hypertension
Congenitally weak vessels
Signs and symptoms of a stroke will depend on what?
Part of brain affected, which part of circulation blocked.
What are the three circulations that can be affected in a stroke?
Anterior circulation
Posterior circulation
Circle of Willis.
Where is the easiest place for a clot to go to?
Middle cerebral artery.
Where does the carotid system supply in the brain?
Most of the hemispheres and cortical deep white matter.
What does the vertebra-basilar system supply in the brain?
Brain stem, cerebellum and occipital lobes.
Motor cortex
movement
frontal lobe
judgement, foresight, voluntary movement
Broca’s area
speech
Frontal lobe
smell
Temporal lobe
intellectual and emootional functions
hearing
Brainstem
Swallowing, breathing, great beat, wakefulness centre and other involuntary functions
cerebellum
coordination
Wernicke’s area
speech comprehension
Brainstem
Swallowing, breathing, heart beat, wakefulness centre and other involuntary functions
parietal lobe
comprehension of language
sensory cortex
pain, heat and other sensations
How do the motor cortex relate to the different parts of the body?
Different parts of the body are stimulated by different parts of the motor complex.
Which arteries supply the motor cortex and why is this useful?
Can tell where the blockage is based on what movements patient is able to do. Anterior cerebral artery supplies anterior section, middle - middle, posterior - posterior.
Even a small stroke in the pons will result in what?
Major deficit as the fibres are packed close together.
What are the causes of a stroke?
Blockage of vessel with thrombus or clot
Disease of vessel wall, e.g. atheromas
Disturbance of normal properties of the blood, e.g. too many red cells or white cells (leukaemia)
Rupture of vessel wall (haemorrhage)
85% due to infarction, 15% due to haermorrhage
What is the most common cause of ischaemic stroke?
large artery atherosclerosis
What is the most common cause of haemorrhagic stroke?
Primary intracerebral haemorrhage
Where do most carotid problems happen?
Bifurcation (major site for atherosclerosis to develop). Proximal disease occurs where vessels branch and areas of bifurcation always more susceptible atheromas.
What is the most common cause of a cardioembolic stroke?
Atrial fibrillation and subsequent emboli.
Small vessel disease risk is increased by what?
hypertension
What are some rare causes of stroke?
Carotid dissection - idiopathic or trauma
Wall of carotid tears and clot formation at top of area of damaged vessel, if the clot heads off can end up with stroke. Shows up as rat tail appearance on angiogram.
From a patients symptoms what can you tell?
If left or right side of brain (opposite from side of symptoms normally)
Carotid territory or vertebrobasilar territory
Cerebral hemisphere or brainstem
Cortex or deep white matter
What blood vessel is involved
Why is important to localise area causing the stroke?
Confirms diagnosis of stroke
Allows better selection of imaging
Gives indication of cause
Gives indication of prognosis
What are the four stroke subtypes?
TACS - total anterior circulation stroke
PACS - partial anterior circulation stroke
LACS - lacunar stoke (perforating BVs affected)
POCS - posterior circulation stroke
What are the common symptoms of TACS?
Usually weakness, sensory deficit, homonymous hemianopia (loss of vision), higher cerebral dysfunction (speech).
What are TACS usually due to?
Occlusion of proximal MCA or ICA.
What are the symptoms of PACS?
2/3 TACS criteria or restricted motor/sensory deficit, e.g. one limb, face and hand or higher cerebral dysfunction alone.
What are PACS usually due to?
More restricted cortical infarcts - occlusion of branches of MCA
What are the symptoms of LAC?
Pure motor (commonest) - complete or incomplete weakness of one side (including 2/3 of face/arm/leg)
Pure sensory - sensory symptoms/signs, same distribution
Sensorimotor - combination of above
Ataxic hemiparesis - hemiparesis and ipsilaterial cerebellar ataxia, small infarcts in basal ganglia or pons. Intrinsic disease of single basal perforating artery (end arteries).
NB. often silent and underdiagnosed.
What are the symptoms of POCs?
Variable, frequently complex presentation, may include:
Bilateral motor/sensory deficit, disorder conjugate eye movements, isolated homonymous hemianopia, ipsilateral cranial nerve palsy with contralateral motor/sensory deficit, coma, disordered breathing, tinnitus, vertigo, Horner’s.
What part of the brain is affected by POCs?
Brainstem, cerebellar or occipital lobes.
What would left optic nerve compression cause?
Unilateral field loss - left
What would chaismal compression from e.g. a pituitary tumour cause?
Bitemporal hemianopia (loss of outer half of vision in both eyes).
What would a blockage in the left cerebrovascular region cause?
Homonymous hernianopia - Loss of vision in right half of both eyes.
