stroke Flashcards
define stroke
serious life threatening condition that occurs when blood supply to brain is cut off and symptoms last longer than 24 hours
define TIA
min strokes but symptoms reverse within in 24 hours
what is the cause of Heamorrhagic stroke ?
Intracerebral (rupture of a vessel in brain parenchyma)
Subarachnoid
what is another cause of stroke other than Ischaemia or haemorrhaigc ?
Dissection (separation of walls of artery, can occlude branches)
Venous sinus thrombosis (occlusion of veins causes
backpressure and ischaemia due to reduced blood flow)
Hypoxic brain injury (e.g. post cardiac arrest)
what is the 2 things you do when suspected stroke comes in ?
check if <4 hours = thombolysis
CT scan
why CT scan ?
rule out haemorrhagic cause . you cant see anything on CT if acute ischaemia . only established infracts show on CT
what can you do for suspected Ischaemic stroke?
MRI- high signal area
what would you see in Anterior cerebral artery infract ?
Contralateral weakness in lower limb/ sensory
Lower limb affected much worse than upper limb and face due to motor homonculus
how can you tell the paracentral lobe when affected ?
Urinary incontinence is present
how can you tell left frontal/ inferior parietal lobe is affected ?
Apraxia- Inability to complete motor planning
what supplies the corpus callosum ? if there is pathology what can it lead to ?
anterior cerebral artery
Split brain syndrome / alien hand syndrome
what happens in frontal lobe damage in stroke ?
Dysarthria / aphasia
what is a complication of MCA infarcts?
haemorrhagic transformation - vessels in the
infarcted area break down
what do you see in MCA infarcts?
full contralateral hemiparesis
Visual field defects- contralateral homonymous
hemianopia without macular sparing
Aphasia
how can you tell if Lacunar stroke or Trunk MCA infarct?
lacunar = higher cortical function is not affected
where would you see sensory loss on MCA infarcts?
o Contralateral -face
and arm, but could involve larger areas if
sensory fibres in internal capsule affected
why is there visual fields defects in MCA infarcts ?
what happens if more distal ?
estruction of both superior
and inferior optic radiations
one radiation affected causing
quadrantanopias
what kind of aphasia in superior MCA infarct? also what limbs are mostly affected ?
Broca’s due to frontal lobe supply - dominant only
contralateral
face and arm weakness
what kind of aphasia in inferior MCA infarct?
what also is affected as well?
Wernicke's (receptive) contralateral sensory change in face and arm optic radiations- visual defects
when would you see global aphasia ?
MCA trunk infarcts
why do you get Contralateral neglect ? what other symptoms may occur with it
lesions of right parietal lobe (non dominant)
Tactile extinction
Visual extinction
Anosognosia
what is the Essential distinguishing feature of a lacunar stroke ?
sub cortical symptoms not cortical e.g. neglect or aphasia
what do you PCA infarcts ? why do you see these signs ?
Contralateral homonymous hemianopia (with macular
sparing due to collateral supply from MCA)
• Contralateral sensory loss due to damage to thalamus
what side will you see cerebellar signs compared to its lesion ?
ipsilateral
what are the signs for cerebellar infarcts
Nausea • Vomiting • Headache • Vertigo / dizziness DANISH
why can you see contralateral sensory deficit / ipsilateral Horner’s in cerebellar infarcts ?
brainstem involvement
what symptoms do you see in brainstem infarcts ?
why do you see these ?
contralateral limb weakness is seen with ipsilateral cranial nerve signs- damage to corticospinal tracts (above decussation of pyramids) and damage to cranial nerve nuclei on same side
what can you see in superior/distil basilar infarcts ?
Visual and oculomotor deficits - (supplies oculomotor nuclei )
Behavioural abnormalities
• Somnolence, hallucinations and dreamlike behaviour
motor dysfunction absent often
what can you see in inferior/proximal basilar infarcts ?
locked in syndrome
• Complete loss of movement of limbs- can move eyes
Preserved consciousness
why is there vertical eye movement in inferior basilar infarcts ?
midbrain is
getting supply from PCAs via posterior communicating
arteries
using Bamford oxford , how can classify TACS?
all 3 of :
unilateral weakness (and/or sensory deficit) of the face, arm and leg
Homonymous hemianopia
Higher cerebral dysfunction (dysphasia, visuospatial disorder)
using Bamford oxford , how can classify PACS?
Two of the following “
Unilateral weakness (and/or sensory deficit) of the face, arm and leg
Homonymous hemianopia
Higher cerebral dysfunction (dysphasia, visuospatial disorder)
using Bamford oxford , how can you classify POCS?
One of:
Cranial nerve palsy and a contralateral motor/sensory deficit
Bilateral motor/sensory deficit
Conjugate eye movement disorder (e.g. horizontal gaze palsy)
Cerebellar dysfunction (e.g. vertigo, nystagmus, ataxia)
Isolated homonymous hemianopia
using Bamford oxford , how can you classify LACS?
One of : Pure sensory stroke Pure motor stroke Senori-motor stroke Ataxic hemiparesis
