Stroke Flashcards
Definition: Stroke
rapid loss of function as a result of reduced blood supply to the brain
Cause: Ischaemic stroke
caused by an interruption of blood supply as a result of blockage or clot (thrombus / embolus)
Cause: Haemorrahgic stroke
results from a weakened vessel in the brain that ruptures and bleeds, which thereafter accumulates and compresses surrounding brain tissue. It may bleed inside the brain (intracerebral) or over the surface of the brain (subarachnoid)
Risk factors: stroke
> 60yrs, hypertension, diabetes, high BMI, smoking, alcohole, atherosclerosis, familiy hx of stroke, hx of stroke or TIA, AF (atrial fibrillation)
Pathophysiology: Ischaemic stroke
Ischaemic stroke is a gradual onset and occurs when there is dysfunction in the endothelium of the blood vessel in the brain or the other parts of the body. It causes build-up of cholesterol, lipids and cellular debris, resulting in formation of plaques stenosing the vessels, which will then reduces the oxygen supply to the brain tissue. Therefore, anaerobic metabolism starts producing less ATP and releases a by-product called lactic acid, which is acidic, and potentially causes necrosis of the brain tissue
Pathophysiology: Haemorrahgic stroke
It is a sudden onset and it also causes lack of oxygen supply to the brain tissue, and same as ischaemic stroke, as the tissue become ischaemic, anaerobic metabolism starts to produce less ATP and releases by-product called lactic acid, which is acidic, and potentially causes necrosis of the brain tissue.
Diagnosis: Stroke
CT scan (x-ray) is less sensitive to detect ischaemic stroke without contrast, but sensitve to identify intracerebral haemorrahge (ICH) in the acute phase (within 24hrs). If later than 8-10 days, MRI should be used to differentiate ICH and ischaemic stroke. Also, angiography can be used (dye the blood and x-ray)
Medical management: Stoke
Medications: tPA (tissue plasminogen activator), aspirin, warfarin are used to thin the blood for ischaemic stroke. For haemorragic stroke, intraventricular catheter (IVC), burr hole are used to drain CSF (cerebrospinal fluid) / blood.
