Stroke- pathology and investigation 1 Flashcards
what is a stroke?
a neurological deficit ( loss of function) of sudden onset and lasting more than 24 hours. It is of vascular origin.
what is a transient ischaemic attack?
a neurological deficit of sudden onset and vascular origin that last less than 24hours
what are the symptoms of a stroke?
loss of power loss of sensation loss of speech (dysphasia) loss of vision loss of coordination
what is aphasia/ dysphasia?
language disorder marked by deficiency in the generation of speech
what must be found out during the history taking of a stroke?
time of onset witnesses headache vomiting neck stiffness photophobia loos of consciousness fit incontinence
if a stroke patient has headache, vomiting, neck stiffness or photophobia what does this suggest?
haemorrhage
what are the findings on examination of a stroke patient?
motor function- clumsy or weak limbs sensory function- loss of feeling speech- dysarthria/ dysphasia neglect/visuospatial problems vsion-loss in one eye, or hemianopia gaze palsy ataxia vertigo incoordination nystagmia
what is nystagmia?
condition in which the eyes make repetitive and uncontrolled movements, sign of stroke
what is ataxia?
neurological sign consisting of lack of voluntary coordination of muscle movements, sign of stroke
what is gaze palsy?
an inability to move both eyes in a single direction
what are the causes of strokes?
- blood vessel occlusion by thrombus or embolus
- haemorrhage
- disease of vessel wall eg. atherosclerosis
- disturbance of the normal properties of blood eg. thick blood from cancer
what is penumbra?
tissue that is alive but not perfused. It is at risk of infarction but can be saved if reperfused
what are the three circulations within the brain?
anterior circulation
posterior circulation
circle of WIllis
what is the Broca’s area of the brain responsible for?
speech
what is the frontal lobe responsible for?
judgement, foresight and voluntary movement
smell
what is the motor cortex of the brain responsible for?
movement
what is the sensory cortex of the brain responsible for?
heat, pain and other sensations
what is the parietal lobe responsible for ?
comprehension of language
what is the temporal lobe responsible for?
- hearing
- intellectual and emotional functions
what is the occipital lobe responsible for?
sight (primary visual area)
what is the Wernicke’s area of the brain responsible for?
speech comprehension
what is the cerebellum responsible for?
coordination
what is the brainstem responsible for?
swallowing breathing heart beat wakefullness centre other involuntary functions
if a stroke is small but affects deep white fibres what will the result be?
it will result in a large deficit as the fibres are packet close together here
what are the 5 causes of ischaemic stroke?
- large artery atherosclerosis
- cardioembolic
- small artery occlusion
- cryptogenic
- rare causes such as arterial dissection and venous sinus thrombosis
what are two kinds of haemorrhagic stroke?
primary intracerebral haemorrhage secondary haemorrhage (subarachnoid or atriovenous malformation)
what does the internal carotid artery supply?
the brain
what does the external carotid artery supply?
the face
what is the main problem caused by brain stem strokes?
inability to swallow
what is the most common cause of cardioembolic stroke?
atrial fibrillation
why is it important to localise stroke?
- confirms the diagnosis of a stroke
- allows better selection of imaging
- gives an indication of cause
- gives an indication of prognosis
what is unilateral field loss?
loss of vision in one eye
what is bitemporal hemianopia?
loss of vision from one half of each, the loss is in the opposite halves
what is homonymous hamianopia?
loss of sight from one side in both eyes, the loss is from the same side in both eyes
what is a total anterior circulation stroke due to?
occlusion of proximal middle cerebral artery or internal carotid artery
what are the symptoms/signs of total anterior circulation stroke?
weakness sensory deficit Homonymous hemianopia (loss of vision) Higher cerebral dysfunction (eg dysphasia, dyspraxia)
what is dyspraxia?
the partial loss of the ability to co-ordinate and perform skilled, purposeful movements and gestures with normal accuracy. (apraxia is the total loss)
what is partial anterior circulation (PACS) caused by?
occlusion of branches of MCA
what are the symptoms of PACS?
2/3 features TACS ie. weakness sensory deficit Homonymous hemianopia (loss of vision) Higher cerebral dysfunction (eg dysphasia, dyspraxia)
what is occluded in lacunar stroke (LACS)?
a lacunar artery
what are the symptoms of LACS?
either:
-pure motor problem problem: Complete or incomplete weakness of 1 side, involving the whole of 2 of 3 body areas (face/arm/leg)
-pure sensory
Sensory symptoms and/or signs, same distribution
-sensorimotor
combination of above
-ataxic hemiparesis
often silent
what is ataxic hemiparesis?
paresis of contralateral leg and side of the face, ataxia of the contralateral leg and arm
which classification of stroke has the best prognosis?
LACs
which classification of stroke has the poorest prognosis?
TACs
which classification of stroke has the highest recurrence rate?
PACs
