Stroke

=Reading= Gelb, Chapter 4 Background information > Definitions >> penumbra: area where ischemia is less severe; reversible longer > Pathophysiology >> mediating factors: tissue lactate, yhydrogen ions, inorganic phosphate, release of excitatory amino acids, increased calcium influx, increaed extracelluular postassium, relase of arachidonic acid, free radical production, apoptosis

> Classification by etiology ischemic, hemorrhagic liphyalinosis from HTN Lacunar infact dissection, arteritis, fibromuscular dyplasia, migraine, antiphospholipid antibody syndrome, ickle cell disease, procoagulatn state berry aneurysm(congenital aneurysm in circle of willis)Hypertensive aneurysmal bursting AV malformation

Approach Management > Reversal of deficits tPA IV w/in 3h of ischemic stroke 30-50% more likely to have minaml or no deficit 3 months later risk of hemorrhage

> Limitaiton ofdeficits control increase in ICP beware of seizure foci watch for SIADH patch for depression...

spport for hypoxia, hypotension, hyperthermia, hyerplycemia watch for DVT and skin ulcers

> Rehab speech, mobility, swallowing evaluate for facilitative devices

Secondary prevention > Diagnosis source may be difficult to pinpoint functional deficits, radiological findings may imply source mitral stenosis, prosthetic heart valve, a-fib
 * look for TIAs
 * risk factor modification: HTN, DM, smoking hyperlipidemia
 * potentially occult causes: coagulopathy, hematologic disorders, arterial dissection, connective tissue disease, infections (like syphilis)

Bruits may suggest location

comma shaped lesions in internal capsul/caudate --usually MCA @ lateral lenticulostriate arteries wedge shaped coritclal infarcts ->mca PATCHY IRREGULAR INFARCT -> HYPOPERFUSION MULTIPLE INFARCTS -> CARDIOEMBOLISM, ATHEROSCLEROSIS, COAGULOPATHY.PENETRATING ARTERY TENDS TO BE LESS THAN 1.5 CM

intra-arterial angiography is still gold standard

> Treatment aspirin other antithrombotic drugs endarterectomy for carotid stenosis warfarin coagulation for cardioembolic disease (atrial fib c/i in bacterial endocarditis

Primary prevention Risk fators: HTN, DM< smoking, hyperlipidemia

=Goals=

C. Antiplatelet agents
> aspirin, clopidogrel, E-R dipyridamole

8. Hemorrhagic stroke
hypertensive vasculopathy, amyloid angiopathy, saccular aneurysms, vascualr malformations