Sites of ischaemic stroke

Question 1

what is ischaemia?

Answer 1

decreased oxygen supply to an area with increased oxygen demands of these tissues

Question 2

What happens if the anterior cerebral artery is occluded?

Answer 2

contralateral loss of sensation + motor control to the lower body (primary motor cortex and primary somatosensory cortex are nearby- medial region (homunculus) therefore lower limb)

Question 3

What happens if the middle cerebral artery is occluded?

Answer 3

• contralateral loss of sensation + motor control to the face and upper limbs
• Broca’s aphasia: inability to produce speech

Question 4

What happens if the posterior cerebral artery is occluded?

Answer 4

supplies occipital lobe (vision)- occlusion of this causes homonymous hemiopias

Question 5

What happens if the basilar artery is occluded?

Answer 5

locked in syndrome- damages corticospinal tracts bilaterally- no movement aside from eye movements with sensation retained

Question 6

What happens if the anterior inferior cerebellar artery is occluded?

Answer 6

• lateral pontine syndrome (cranial nerve VII): paralysis of facial sensation
• vestibular nuclei damage: vertigo, nystagmus, possible deafness, poor coordination + muscle tone
• spinothalamic tract affected causing contralateral loss of pain and temperature

Question 7

What happens if the anterior spinal artery is occluded?

Answer 7

medial medullary syndrome: hypoglossal nerve- ipsilateral palsy (swallowing, tongue movements, word pronounciation affected); contralateral hemiplegia (loss of motor control); medial meniscus affected (contralateral loss of touch, pressure, vibration, proprioception)

Question 8

What happens if the posterior- inferior cerebellar artery is occluded?

Answer 8

• cerebellar symptoms- poor coordination, loss of muscle tone, affected balance
• vagus nerve damage: may cause dysphagia (difficulty swallowing- negative gag reflex)
• damage to sympathetic fibres (pupil constriction, no sweating, drooping of upper eyelid)
• contralateral pain and temperature sensation loss due to the spinothalamic tracts being affected