what is stroke
sudden interruption in the vascular supply of the brain
- ischaemic
- haemorrhagic
what things can cause an ischaemic stroke
- thrombus
- embolus
- atherosclerosis
- shock
- vasculitis
what conditions can increase risk of haemorrhagic stroke
hypertension**
aneurysms
AV malformations
head trauma
what are the risk factors for a stroke
Previous stroke or TIA
Atrial fibrillation
Carotid artery stenosis
Hypertension
Diabetes
Raised cholesterol
Family history
Smoking
Obesity
Vasculitis
Thrombophilia
Combined contraceptive pill
what are TIAs
temporary neurological dysfunction (lasting less than 24 hrs) caused by ischaemia but without infarction
what are crescendo TIAs
> 2 TIAs within a week
indicate high risk of stroke
presentation of stroke
Sx typically asymmetrical
limb weakness
facial weakness
dysphasia
visual field defects
sensory loss
ataxia + vertigo
what is the management of a TIA
Aspirin 300mg daily (started immediately)
referral to neuro –> diffusion weighted MRI scan
what are lacunar infarcts
small infarcts around the basal ganglia, internal capsule, thalamus and pons
may result in pure motor, sensory or mixed signs or ataxia
what is the standard criteria for thrombolysis
administered within 4.5 hrs
haemorrhage has definitely been excluded
what should the BP be lowered to before thrombolysis
185/110
who is thrombectomy useful for
those presenting within 6hrs together with IV thrombolysis to those with occlusion of prox anterior circulation
if between 6 and 24hrs offer if they have proximal anterior circulation stroke and there is potential to salvage brain tissue if depicted by CT perfusion or diffusion weighted MRI
same applies for proximal posterior circulation
what secondary prevention should be commenced following stroke
- clopidogrel
(aspirin only if above contraindicated)
other management considerations post stroke
- fluid management - to ensure normovolaemic ( recommend oral but IV if not able to swallow)
- glycaemic control esp as will be nil by mouth. take extra care in diabetics. aim for levels to be around 4-11
- must be screened for safe swallowing,
other options include NG feeding or gastrostomy - disability scale –> level of function using barthel index
- rehabilitation?
what causes of stroke are investigated in every pt
- CA stenosis – CA ultrasound
AF – ECG
how should BP be managed in ischaemic stroke vs haemorrhagic
lowering the blood pressure can worsen the ischaemia. High blood pressure treatment is only indicated in hypertensive emergency or to reduce the risks when giving intravenous thrombolysis. Blood pressure is aggressively treated in patients with a haemorrhagic stroke.
ACA stroke deficit
Contralateral hemiparesis and sensory loss, lower extremity > upper
MCA artery deficit
Contralateral hemiparesis and sensory loss, upper extremity > lower
Contralateral homonymous hemianopia (if damage to optic radiations occurs)
Aphasia (brocas and wernickes supplied by this)
PCA deficit
Contralateral homonymous hemianopia with macular sparing
Visual agnosia
what is webers sydrome
stroke with ipsilateral CN III palsy – down and out eye
Contralateral weakness of upper and lower extremity
supplied by branches of PCA that supplies midbrain
PICA stroke deficit
lateral medullary syndrome/ wallenberg syndrome
Ipsilateral:
Facial pain & temperature loss (CN V)
Ataxia (cerebellum)
Horner’s syndrome (ptosis, miosis, anhidrosis)
Contralateral:
Body pain & temperature loss (spinothalamic tract)
AICA stroke deficit
also known as lateral pontine syndrome
Ipsilateral:
Facial paralysis (CN VII)
Hearing loss / vertigo / tinnitus (CN VIII)
Ataxia (cerebellum)
Contralateral:
Body pain & temperature loss (spinothalamic tract)
retinal artery or ophthalmic artery deficit
amaurosis fugax
basilar artery deficit
locked in syndrome
