Stroke Flashcards
What is a cerebrovascular accident ?
Stroke
Types
ischaemic stroke - blockage of blood flow
Haemorrhagic stroke - burst blood vessel - blood spills out and pools in the brain interrupting blood flow and increase in pressure in the brain
Left side of the brain - controls right side
Right side of the brain controls left side.
- TIA - transient ischaemic attack - blood supply to brain temporarily interrupted.
FAST acronym -Stroke
Facial drooping - one side
Arms - weakness or numbness in one arm (not able to lift both arms and keep it there)
Speech - slurred , not able to talk while awake, problems understanding
Time - call 999
Management of Transient ischaemic attack.
Suspected TIA
- Referral to specialist TIA unit for assessment and investigation.
- Aspirin 300 mg daily immediately (unless contraindicated)
- MRI to detect territory of ischaemia or haemorrhage
- same days as assessment.
- Secondary prevention of occlusive events :
Modified-release dipyridamole in combination with aspirin - FIRST OPTION
Modified-release dipyridamole without aspirin - (ONLY WHEN ASPIRIN USE IS CONTRAINDICTAED OR NOT TOLERATED)
- DO NOT OFFER CT SCAN TO SUSPECTED TIA PATIENTS -unless there is clinical suspicion of an alternative diagnosis that CT could detect.
- Everyone with TIA who after specialist assessment is considered as a candidate for carotid endarterectomy (REMOVE PLAQUE BUILD-UP IN CAROTID A. OF NECK)should have urgent carotid imaging.
Management of Acute stroke ?
- Non -enhanced CT scan immediately
- Maintain a blood glucose concentration between 4 and 11 mmol/litre in people with acute stroke.
* Provide optimal insulin therapy, which can be achieved by the use of intravenous insulin and glucose, to all adults with type 1 diabetes with threatened or actual stroke. - thrombectomy + intravenous thrombolysis as soon as possible and within 6 hours of symptom onset,
- thrombolysis - clot busting drugs injected.
- Aspirin 300mg (2 weeks after symptom onset) or other anti -platelet drug
0 oral - no dysphagia
0 rectally - rectally or enteral tune -if dysphagia present.
5.long-term antithrombotic treatment - after 2 weeks or before is discharged before 2 weeks.
- you would screen patient for dysphagia (common after stroke -impaired GAG REFLX) - too see they can eat normally to avoid poor nutrition etc.
0 dysphagia can lead to aspiration of saliva and gastric contents and anything swallowed leading to pneumonia (infection inflames air sacs of lung)
Acute stroke - middle cerebral infarct
Consider decompressive hemicraniectomy for middle cerebral artery infarction
- consider for following criteria
0 clinical deficits that suggest infarction in the territory of the middle cerebral artery, with a score above 15 on the NIHSS
0 decreased level of consciousness, with a score of 1 or more on item 1a of the NIHSS
0 signs on CT of an infarct of at least 50% of the middle cerebral artery territory:
with or without additional infarction in the territory of the anterior or posterior cerebral artery on the same side
or
0 with infarct volume greater than 145 cm3, as shown on diffusion-weighted MRI scan.
Acute stroke - carotid stenosis
Have symptomatic carotid stenosis of 50% to 99% according to the NASCET criteria with symptoms of non-disabling stroke or TIA:
0 assessed and referred urgently for carotid endarterectomy
0 receive best medical treatment - control of blood pressure, - antiplatelet agents, - cholesterol lowering through diet and drugs, lifestyle advice).
carotid stenosis of less than 50% according to the NASCET criteria, or less than 70% according to the ECST criteria with non-disabling stroke or TIA:
0 do not have surgery
0 receive best medical treatment
Management of Haemorrhagic stroke
Medical management - with medicine
surgical - presence of hydrocephalus following primary intracerebral haemorrhage
Hydrocephalus - accumulation CSF in brain
intracerebral haemorrhage -
* if on warfarin give prothrombin complex concentrate + intravenous potassium to return blood clotting kevels to normal as soon as possible
0 blood pressure control rapid blood control - if present within 6 hours of symptom onset + systolic pressure - 150 -220 mmHg
- if present after 6 hours of symptom onset + systolic pressure > 220 mmHg
- Aim for a 130 -140mmHg within 1 hour of starting treatment.
Do not offer rapid blood pressure lowering to people who:
0 have an underlying structural cause (for example tumour, arteriovenous malformation or aneurysm)
0 have a score on the GCS of below 6
0 are going to have early neurosurgery to evacuate the haematoma
0 have a massive haematoma with a poor expected prognosis.
Consequences of haematomas growth ?
haematoma growth ——> increase intracranial pressure ———> midline shift (displacement of brain)
Increased intracranial pressure causes :
- cushing’s triad
0 increased BP
0 Bradycardia
0 irregular breathing
Lumbar puncture - contraindication ibn increased intracranial pressure.
What is uncal herination ?
uncus (innermost part of temporal lobe moves down and compresses brain stem.
- compression of oculomotor nerve - nerve palsy
What is external herniation ?
Transcalvarial - Brain leaves leaves skull through fracture or surgical site.
What is Cingulate herniation ?
Subfalcine - Cingulate gyrus squeezes past falx cerebri
to the opposite side
- falx cerebri - separates left and right hemisphere.
- compress anterior cerebral artery -ischaemic stroke.
What is central herniation ?
trans- tentorial - dicephalon and part of temporal lobe move down past tentorium
.- effects cerebrum -supratentorial
What is upward cerebellar herniation ?
Cerebellum displaced upwards through notch in tentorium cerebelli
effects cerebellum - infratentorial
What is downward cerebellar herniation ?
Tonsillar herination.
Cerebellum tonsil slips through magnum forearm.
Can compress nerves - responsible for breathing and cardiovascular function
Dysphagia (abnormal gag reflex) and stroke - what is done about it ?
Enteral feeding - PEG tube - percutaneous endoscopic gastrostomy
or Nasogastric tube
Due to high risk of aspiration and poor nutrition.