Nervous system: Stroke Flashcards
In ischaemic strokes, what are the common sites clots can originate from?
The carotid arteries: clots can form in atherosclerotic regions and break off into the circle of willis
The heart: AF causes stagnation of blood and therefore clots, prosthetic valves, infective emboli
The vertebral/basilar arteries: cause a posterior circ stroke
Outline the main arteries of the anterior and posterior circulation
Anterior circ: from the internal carotids, anterior and middle cerebral arteries
Posterior circ: posterior cerebral arteries, cerebellar arteries
What area of the brain does the anterior cerebral artery supply?
Medial aspects of the frontal and parietal lobe
Anterior part of the corpus callosum
How would a patient present with an anterior cerebral artery stroke?
Sensory: contralateral, loss of all modalities of the lower limb (medial aspect of post-central gyrus)
Motor: contralateral, lower limb affected more than upper limb (medial aspect of pre-central gyrus) would initially be flaccid then spasticity (UMN signs)
Medial aspect of cortex also responsible for continence so would be incontinent
What area of the brain does the middle cerebral artery supply?
The majority of the hemisphere, particularly the lateral aspects. Also supplies the internal capsule and the macular cortex (thats why you get macular sparing)
How would a patient present with a middle cerebral artery stroke?
Sensory: contralateral, loss of all modalities in the upper limb and face (lateral aspect of post-central gyrus)
Motor: contralateral, upper limb and face affected more (lateral aspect of pre-central gyrus), initially flaccid then spasticity (UMN signs) - can also affect the leg if the lesion is more proximal as this affects the internal capsule.
- vision changes
- can get brocas, wernickes or global aphasia
- hemispatial neglect
- tactile extinction (touch R and L separately will feel both but touch together they will neglect 1 side)
What complications can arise as a result of middle cerebral artery occlusion?
Main trunk occlusion causes considerable cerebral oedema which can lead to coma or death.
A decompressive hemi-craniotomy can be performed to relieve raised IC pressure however this can cause significant disability.
What area of the brain does the posterior cerebral artery supply?
The occipital lobe and inferior portion of the temporal lobe
How would a patient present with a posterior cerebral artery stroke?
Visual changes:
- contralateral homonymous hemianopia with macular sparing (can also get this with a middle cerebral artery infarct however this would present with may other symptoms)
How would a patient with a cerebellar artery stroke present?
A distal occlusion:
Would get ipsilateral signs - DANISH
A proximal occlusion:
Would get DANISH cerebellar signs as well as some brainstem signs
How would a patient with a basilar artery stroke present?
May cause bilateral symptoms because it is a midline artery.
Proximal occlusion - locked in syndrome
Distal occlusion - blindness, sensory loss, LOC, bilateral midbrain signs
How would a patient with a lenticulostriate artery occlusion present?
Would get a lacunar stroke
Pure motor symptoms: ipsilateral because the fibres have not yet crossed over, would involve the face arm and leg, would be flaccid followed by spasticity (UMN signs)
How would a patient with a thalamoperforator artery present?
Supplies the thalamus so get a pure sensory stroke
Complete sensory loss of all modalities of the face arm and leg
What are some common stroke mimics?
HEMI: Hypoglycaemia (big stroke mimic) Epilepsy Migraine (should consider this in younger pts) IC tumours or infections
