Stroke and Hemorrhage Flashcards
Infarct
necrotic region of tissue
Stroke
abrupt incident of vascular insufficiency resulting in loss of neurologic function
Occlusive (Ischemic) Stroke
70- 80%
Thrombotic and Embolic
reduced blood supply leads to hypoxia which can lead to tissue death (infarction)
Hemorrhagic Stroke
not due to trauma
Intracranial and Subarachnoid Hemorrhages
rupture of vessel
Penumbra
region surrounding area of permanent tissue damage
will survive if treated quickly
3 hours to treat
Thrombotic Stroke
clots form locally over atherosclerotic lesion
has prodromes- vasospasms and partial occlusion- transient ischemic attack
Embolic Stroke
thrombus detaches and lodges in artery
no prodromes
Watershed Infarct
hypoxia due to insufficient blood supply
hypotension
affects vulnerable sites
Causes of Subarachnoid Hemorrhage
aneurysm rupture
arteriovenous malformation
Causes of Intracerebral Hemorrhage
hypertension
arteriovenous malformation
Focal
due to artery occlusion or small hemorrhage
certain area of brain is affected
neural deficits at multiple sites
Diffuse
whole or multiple parts of brain are affected
patient normally unconscious
Hemorrhage in Parenchyma
rupture of small artery
leads to accumulation of blood within brain and compression of adjacent tissue
Hemorrhage in Subarachnoid Space
rupture of superficial artery
blood compresses brain underneath
Transient Ischemic Attack
vascular attack w/ symptoms similar to stroke
deficits only last for a few minutes
monocular blindness
often precede stroke
Sources of Emboli
left atrium of heart
carotid arteries
paradoxycal- venous embolus, cerebral artery
Locations of Ischemic Stroke
MCA
Internal Carotid near bifurcation
Basilar A
Ischemic Stroke Effects
brain swelling
myelin breakdown
demarcation b/t gray and white matter
Gliosis
reaction to injury microglial cells remove necrotic tissue astrocytes proliferate at margins of infarct cystic area develops necrosis of brain tissue
Strokes involving MCA
sensory loss in face and upper extremity
pure motor, pure sensory, and isolated symptoms- monoparesis and isolated sensory loss
Strokes involving ACA
contralateral hemiparesis and sensory loss in lower extremity
urinary incontinence
Strokes involving Vertebral Basilar System
Vertigo and Ataxia
Posterior Inferior Cerebellar Artery supplies….
PICA
lateral medulla
occlusion causes Wallenberg syndrome
Strokes involving Posterior Cerebral Artery
gaze paralysis- 3 nerve palsy
Visual Field Defects- eyes look toward lesion
Contralateral sensory loss