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abrupt onset of focal or global neurological impairment...

of 24+ hours...

caused by ischemia or hemorrhage

3

1

1:1000

80% ischemic

20% hemorrhagic

no effect                                  (anastomoses compensate)


transient physiological disturbance    (TIA)


selective neuronal necrosis             (incomplete infarct)
       just affects neurons; glia are intact

pan-necrosis of neurons & glia            (complete infarct)

red neuron is a dead neuron

24h:    neutrophils
48h:    macrophages
wks:    debris removed  =>  space

peak within 2 days, remains for 1 week

global
   due to cardiac arrest, systemic hypotension, increased ICP
   widespread, multifocal ischemic necrosis
   especially pronounced in border zones / watershed areas
   symmetric


focal
   emboli
   occlusion of blood vessel
   infarction

occlusion of lenticulostriate / penetrating artery...

...due to small vessel arteriosclerosis

hypertensive small vessel disease

cerebral amyloid angiopathy

ruptured vascular malformation

drugs     (cocaine, amphthemine)

neoplasm

ruptured Berry aneurysm

bleeding diathesis

trauma

rupture of arteriosclerotic small penetrating artery

parenchymal brain hemorrhage

arise at forks of arteries in CoW

85% in anterior circulation
15% in posterior circulation

5% prevalence

most do not rupture
    annual risk of <1%

elevated ICP

rebleeding

vasospasm

hydrocephalus

congenital

tangle of abnormal arteries & veins with no intervening capillary bed

wedge-shaped

involve brain & meninges

can rupture into subarachnoid space or brain

annual risk:   3%

feeder vessels can develop berry aneurysms

=  cavernous angioma

small, tightly-packed group of thin-walled blood vessels

annual risk of rupture:  <1%


can cause seizures

can be familial

can be multiple

stroke

ischemic
   atherosclerotic
      large artery atherothrombosis     (extracranial, intracranial)
      small artery atherothrombosis     (lacunar infarction)
   embolus
      intra-artery
      cardiogenic
      paradoxical               (R=>L heart via patent foramen ovale)
   systemic hypotension / cardiac arrest

hemorrhagic
   brain hemorrhage
         due to hypertension, cerebral amyloid angiopathy
   subarachnoid hemorrhage
         due to ruptured berry aneursym

transient episode of focal neurological dysfunction resulting from ischemia...


...not associated with permanent cerebral infarction

...always <24hrs

history

neurological exam

localization

CT to evaluate for blood

thrombolysis

supportive management

diagnosis of pathophysiology

secondary prevention

rehabilitation

ischemic stroke
   identify & remove cause
   antiplatelet drugs:
         aspirin, clopidogrel
   risk factor modification
         BP, cholesterol, smoking, diabetes
         anticoagulation in atrial fibrillation
         carotid endarterectomy in carotid stenosis


hemorrhagic stroke
    identify and remove cause of bleeding
    BP management