Changes On CT Scan In Ischaemic Stroke

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Changes On CT Scan In Ischaemic Stroke

• Nadine MacCowan

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CT Changes In Ischaemic Stroke

• When there is ischaemia in the brain the water
  content of the affected brain tissue increases
  and it swells
• Ischaemia causes low attenuation and so the
  affected brain tissue is darker than usual
• Changes cant be seen immediately usually takes
  12-18 hours so very early ischaemic changes may
  not be seen

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Early CT Changes In Ischaemic Stroke

• Loss of insular ribbon
• Loss of grey-white interface
• Loss of sulci
• Acute hypo density
• Mass effect
• Dense MCA sign

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Late CT Changes In Ischaemic Stroke

• Associated oedema with midline shift may be
  present
• After 24 - 48 hours irregular enhancement of the
  cortex appears

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Ischaemic Stroke Does Not Alter CT For Several
Hours

• These patients need treatment to reestablish as
  much blood flow as possible to prevent cell death
  and permanent loss of function
• However still need to wait for CT changes to
  make sure it is an ischaemic and not a
  haemorrhagic stroke

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Anterior Cerebral Artery Ischaemic Stroke

• Blockage in anterior cerebral artery
• Stops supply of blood to top of the cortex,
  internal capsule, caudate nucleus and lentiform
  nucleus

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Anterior Cerebral Artery Ischaemic Stroke
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Anterior Cerebral Artery Ischaemic Stroke

• Not very common
• Typical symptoms
• Hemiplegia/hemiparesis
• Neglect (right hemisphere damage)
• Aphasia and apraxia (left hemisphere damage)
• Sensory loss
• Urinary incontinence
• Mental status impairment

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Middle Cerebral Artery Ischaemic Stroke

• Blockage in middle cerebral artery
• Stops supply of blood to lateral hemispheres, the
  biggest portion of the cerebral cortex

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Middle Cerebral Artery Ischaemic Stroke
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Ischaemic Stroke In Posterior Branch Of Middle
Cerebral Artery
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Middle Cerebral Artery Ischaemic Stroke

• Very common
• Typical symptoms
• Contralateral hemiparesis
• Dysarthria
• Dysphasia (if dominant)
• Dysphagia
• Dysgraphia/dyslexia
• Hemianopia

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Posterior Cerebral Artery Ischaemic Stroke

• Blockage in posterior cerebral artery
• Stops supply of blood to thalamus, lentiform
  nucleus, medial geniculates, medial temporal
  lobe, occipital lobe and choroid plexus

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Posterior Cerebral Artery Ischaemic Stroke
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Posterior Cerebral Artery Ischaemic Stroke

• Typical symptoms
• Visual deficits (e.g. hemianopia)
• Memory deficits
• Alexia/dyslexia

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Internal Carotid Artery Ischaemic Stroke

• Blockage in internal carotid artery
• Divides to form anterior and middle cerebral
  arteries so has huge effect on brain

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Anterior and Middle Cerebral Artery Infarction
Following Internal Carotid Artery Occlusion
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Internal Carotid Artery Ischaemic Stroke

• Typical Symptoms
• Ipsilateral blindness
• Dysphasia
• Spatial problems
• Hemineglect