Week 10: Stroke and Concussion Flashcards
Only 2 things can happen with stroke- bleed or clot in 2 arteries: what are they?
1- Vertebral Artery – becomes Basilar artery – hence VBI
20% blood supply to brain
o Supplies the Brainstem and Pons
o 5-10% all strokes – risk of death 5%, much better outcomes o Low mortality – visual changes 80%, sensory 18%, motor 6%
2- ICA (internal carotid) – contributes to Circle of Willis – middle, anterior, posterior portions
What is a stroke?
Whats a transient Ischaemic attack?
A stroke is a focal, non-convulsive, neurological defect caused by a vascular lesion, lasting more than 24 hrs.
- stroke is 3rd cause of death in developed world.
- onset sudden
- thromboembolic vascular occlusion accounts for 85%
TIA:
A transient ischaemic attack (TIA) or ‘mini stroke’ happens when the blood supply to the brain is interrupted for a short period of time. It is often called a ‘mini-stroke’, as the signs are the same as those of a stroke, but they do not last as long.
a focal, non-convulsive, neurological defecit lasting less than 24 hrs, with complete clinical recovery caused by hypooperfusion within the brain
What are the clinical features of TIA- only difference to stroke is it resolves within 24hrs, a clot then breaks down.
In the carotid arteries
In the vertebrobasilar arteries
5
• Carotid arteries
o Dysphagia
o Contralateral hemiparesis
o Contralateral homonymous visual field loss o Any combination of the above
• Vertebrobasilar arteries o Diplopia o Vertigo o Dysarthria/dysphagia o Unilateral/bilateral alternating paresis or sensory loss o Binocular visual loss – both eyes used together o Ataxia o LOC (rare) o Any combination of the above
What are the causes of stroke/ TIA?
• Atherosclerosis
o This causes thrombotic stroke in large extracranial arteries, most commonly the carotid arteries or from intracranial arteries
• Cardiac embolism
o Usually originates from pieces of ruptured atherosclerotic plaques
lodging in distal narrow sites.
o It occurs after a MI in arterial fibrillation
• Intracerebral haemorrhage
o Most often the result of untreated hypertension
o Can be caused by trauma, anticoagulant therapy, neoplasia and coagulation disorders
What are the risk factors for stroke/ TIA?
7
• Hypertension
o This is one of the major factors in the development of ischaemic and haemorrhagic stroke
• Diabetes mellitus
o Increases the risk of cerebral infarction two fold. o Also a known risk for atherosclerosis
• Cardiac disease
• Hyperlipidaemia
o More of a risk factor for cardiac disease
• Smoking
• Family history ?
• Obesity
o More of a risk factor for cardiac disease
• Oral contraceptive
o Increases the risk in vulnerable people
Look at table on slide 8 which is the assessment sheet of a stroke?
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What are the signs and Symptoms of a stroke? (negative vs positive signs)
- Sudden numbness or weakness of the leg
- Sudden confusion or trouble understanding
- Sudden trouble seeing in one or both eyes
- Sudden trouble walking, dizziness, loss of balance or coordination
- Sudden severe headache with no known cause
- Face drooping
- Arm weakness
- Speech difficulty
FAST driven by the national Stroke Foundation
• Face =check face, has their mouth drooped
• Arms = can they lift both arms
• Speech = Is their speech slurred? Do they understand you ?
• Time = is critical, act immediately dial 000
Middle cerebral artery occlusion
tell me some stuff about this artery, i.e. what does it supply
What would be the signs of an occlusion of this artery?
• Middle cerebral artery occlusion
o Largest branch of the internal carotid
o Largest part of cerebral cortex supplied o Most commonly involved artery in stroke
o Supplies
• Motor to upper limb, face, mouth, lips
• Area for comprehension (Wernicke’s area)
• Area for expression of speech (Broca’s area)
• These two areas are only in the dominant hemisphere
o Signs
• Contralateral hemiplegia – lower 1⁄2 face, upper + lower limbs
• Contralateral cortical hemisensory loss – face, arm, leg
• Aphasia in the dominant hemisphere – Broca / Wernicke area
• Dressing apraxia in non-dominant hemisphere as perceptual deficits – neglect, apraxia, anosognosia
• Contralateral homonymous hemianopia- (gaze preference to the side of the lesion
view slide 13
Anterior cerebral artery occlusion
supplies what?
signs of occlusion?
slide 16
• Anterior cerebral artery occlusion
o Branch of the internal carotid o Runs above the optic nerve o Unusual to occur on its own
o Signs
• Incontinence – as hemiparesis contralaterally in lower limbs
and pelvic floor musculature
• Associated sensory deficits – leg perineum
• Occasional presence of grasp reflex and other primitive reflexes
• If corpus callosum involved then “disconnection syndrome”
“Disconnection syndrome can also lead to aphasia, left-sided apraxia, and tactile aphasia, among other symptoms”
Supplies occipital lobe = visual defects such as agnosia (recognize common objects), prosoagnosia (recognize faces), corticol blindness (visual impairment but pupil to light reflex is retained, can describe colour and shape but not identify the object
Posterior cerebral artery occlusion- terminal branches of the basilar artery
Supplies?
Signs?
Clinical syndromes
• Posterior cerebral artery occlusion
o Terminal branches of the basilar artery
o Supplies
• Temporal lobe and Occipital lobes
• Visual cortices
• Midbrain
• Thalamus
o Signs
• Proximal occlusion
o Weber’s syndrome
o 3rd nerve palsy – drooping eye, fixed wide pupil (down & out) may mean diplopia
o Contralateral hemiplegia - weakness upper + lower limb typical UMN findings
o Hemisensory disturbance –
o Contralateral Parkinsonism + CXII + contralateral lower facial muscle
What are the signs and symptoms of carotid artery schema/ stenosis?
1. Confusion 2. Dysphasia 3. Headache 4. Anterior neck and/or facial pain 5. Hemianesthesia 6. Hemiparesis or Monoparesis 7. Visual field disturbances 
Subarachnoid haemorrhage
What is it?
S & S?
A bleed into the subarachnoid space as a result of trauma or more
commonly spontaneous bleed
o Severe headache (thunderclap headache usually to the occipital region - seconds to minutes)
o Worst headache they have ever had
o Transient or prolonged LOC or seizure
o Nausea and vomiting – due to increased ICP
o Drowsiness or coma
o Signs of meningism occur after 3-12 hours – trilogy of neck stiffness, HA, photophobia
o Focal signs – depending where bleed is o Papilloedema
Subdural haemorrhage-
• Rupture of cortical veins bridging the dura and the brain. Almost always
caused by trauma. Eg MCA
• Can be acute or chronic • Chronic
o Common – watch elderly Rx anticogulants
o Initial injury may be minor
o Maybe a latent period of days to months o Symptoms may
• Be slow progressing • Fluctuate
• Include
o Headache – mc unilateral with slightly enlarged pupil o Drowsiness – a key feature NB !!
o Confusion
o Focal deficits may occur – abnormal DTR’s, U/L drift, . . o Nausea , vomiting
o Seizures ?
o Vision – impaired or double, dilated / nonreactive pupil ipsi
Epidural haematoma?
slide 21
- evolve more rapidly and are more treacherous,
- in 10% of severe head injuries,
- mc unconscious on presentation,
- LOC within minutes to hours
Concussion
Patient stunned or brief LOC after minor head injury
• Fully alert within minutes
• Residual HA, dizziness, faintness, nausea, single emesis, concentration difficulties, slight blurring vision. Possible vasovagal syncope.
• Typically good prognosis, observe “several hours”
• Persistent HA, repeated vomiting with normal alertness and no focal neurological signs is most
likely benign, but precautionary CT? influenced by extent of the original trauma, degree of surveillance after discharge?
