CNS Stroke Flashcards
What are the 2 main types of stroke
Haemorrhagic and Ischemic stroke
What are the 3 main causes of Ischemic stroke
Thrombotic
-due to a local arterial obstruction
»_space;atherosclerosis
»_space;fibromascular dysplasia
- Affect large vessels eg internal carotid artery
-small vessels such as Basilar artery
- »_space;when they attack these small vessels they are called LACUNAR STROKES
LACUNAR STROKES
-Hemiparsis
-Ataxia
-Disarthria
-Numbness in contralateral face, arm and leg
Embolism stroke
(Blood vessel blocked by emboli)
-Erises from the heart, Cardioembolic
»_space;AFib causing blood to stagnate in the artery and form clots
-Embolus might dislodge from a thrombus
(eg. in carotid artery and affect upper parts of the brain)
»_space;Thromboembolic
»_space;Atheroembolic
-Paradoxical Embolus
»_space;Thrombus in the vein might dislodge
»_space; sips through patent foramen ovale or ASD
-Hypoxic Stroke
»Hypoxic ischemic injury- due to systemic hypoperfusion or hypoxemia
» particularly in infants due to ischemia during birth
»_space;septic shock
» drowning
Describe the aetiology of haemorrhagic stroke
- Blood vessel breaks
-compresses and damages surrounding brain tissue - Intracerebral haemorrhage
-occurs within the brain itself
-Ass/w hypertension - Subarachnoid haemorrhage
-between pia matter and arachnoid mater
- often caused by ruptured aneurysm
Which areas are affected in an anterior cerebral artery stroke
Feet and legs
Which areas are affected in a middle cerebral artery stroke
Face, hands and arms
Language centres of the dominant hemisphere incl Brocas and Wenickers area
Which areas of the brain are affected by posterior cerebral artery stroke
Visual cortex
Differentiate between Motor pathway and sensory pathway deficits on presentation (how do you see it’s sensory or motor)
Motor pathways
-Flaccid paralysis occurs immediately
-Spastic paralysis and hyperreflexia occurs after
Sensory pathways
Numbness
Reduced pain and vibration sensation
In which area of the brain do we get strokes that affect both sides of the body and not contralateral to the area of brain affected
Brain stem stroke
Describe your approach to a pt presenting with stroke
-Assess ABC (Airway, breathing and Circulation)
»_space;intubation may be needed in muscular airway obstruction with Resp decrease)
»_space; Hypoxic pt given supplemental oxygen
»_space;02 SAT >94%
»_space; check glucose level
»_space;CBC : PLATELET COUNT, PT (prothrombin time), PTT (Partial thromboplastin time), INR, FIBRINOGEN.
»_space;Cardiac monitors
»_space;ECG- arrhythmias eg AFib
Why would you not give anticoagulants if a pt has suspected thrombocytopenia when having a stroke
Risk of haemorrhagic stroke occurring
Outline stroke mimics
Complicated migraines
-Preceding aura- strange light or smell
-hx of migraines
Seizures
Post-ictal period- weakness on one side of the body
Todd’s paralysis
Brain tumours
-Gradual progression of symptoms
-Symptoms
Name one major symptom of a Subarachnoid henorrhage
Worst headache of a persons life
What consists of a Full neurological exam in a patient with stroke
NIH Stroke scale
Check pulses in neck, arms and legs
Neck and Retroorbital regions should be auscultation for bruits
Investigations in stroke after exam
- CT scan - ischemi and haemorrhagic
(Contrast should be avoided to avoid mistaking contrast for blood)
Blood is white, ischemia is dark
MRI more sensitive but less available
CT is safer and easily accessible - Lumbar puncture to look for RBC if a subarachnoid haemorrhage is suspected
- Xanthochromia- if CSF appears yellow which means that blood has been in the CSF
Haemorrhagic stroke from hypertension
-Homogenous appearing hematoma
Recent head trauma
-Pattern consistent with the injury
Management of Ischemic stroke
> > Thrombosis is with Recombinant tissue plasminogen activator rtPA
Ischemia most severe in the core
rtPA focuses on penumbra
-3hours for elderly or those with diabetes
-4.5hours for individuals
rtPA is administered intravenously
- can potentially cause severe bleeding
-can lead to haemorrhagic stroke
Time calculated from when the patient was last seen healthy
