Acute Stroke Flashcards
CVA
interruption of blood supply to any part of the brain which results in hypoxic cellular injury, the interruption may be thrombotic or hemorrhagic
leading cause of disability in the US
3rd most common cause of death in women and 5th cause in men
most strokes occur after 65 yr and are ischemic
greatest population risk African American
risk factors for CVA
uncontrolled HTN, smoking, insulin resistance, DM, polycythemia, thrombocytopenia, low HDL and high cholesterol, elevated lipoprotein-a, heart failure, peripheral vascular disease, hyperhomocysteinemia (vitamin B12 B6 and folate deficiency), fib, physical inactivity, family hx, genetics, sleep apnea, chlamydia infection, sickle cell anemia, post-menopausal hormones therapy, high sodium intake, low potassium intake, obesity and depression.
Ischemic stroke: TIA
transient ischemic attack
neurologic dysfunction not lasting longer than 1 hour results from focal cerebral ischemia. a TIA warning sign of impending stroke.
up to 17% of persons will go on to have a stroke in 90 days.
clots that temporarily blocks the flow of blood and then it dislodges in time to reverse cellular injury.
S/S: weakness, numbness, sudden confusion, loss of balance, loss of vision or sudden severe headache
Thrombotic stroke
occlusion of the arterial blood supply to a portion of the brain which is fed by the occluded artery
common type of stroke in atherosclerosis similar to CAD
inadequate perfusion, conditions which increase coagulation, prolong vasoconstriction all increases the risk of thrombosis
Embolic stroke
results from fragments of a thrombus from outside the brain
the fragments get lodged in and block the arterial blood flow to the brain
common Afib stroke
RF: Afib, LV thrombus, LV aneurysm, recent MI, rheumatic valvular disease, mechanical prosthetic valve, patent foramen oval, endocarditis and carotid artery disease.
persons with an embolic stroke will likely have another because the source of embolus tends to remain present.
Lacunar Stroke
small infarcts of less than 1 cm which occurs throughout the brain tissue and involves small arteries
commonly associated with HTN, DM, HLD, and smoking
25% of ischemic strokes
Hemorrhagic stroke
intracerebral hemorrhage can be massive, small or even the size of a petechiae
RF: HTN, previous CVA, CAD and DM
common causes: HTN, ruptured aneurysms, AV malformation, coagulation disorders (hemophilia or excess Coumadin) bleeding secondary to tumor
common in the elderly on anticoagulants (afib)
commonly affected site is the putamen of the basal ganglia, thalamus, cortex, sub-cortex, pons, caudate and cerebellar hemispheres
Cerebral Circulation
supplied by the internal carotid arteries and the vertebral arteries
internal carotid
become the middle and anterior cerebral arteries.
-supplies blood to top portion of the brain
vertebral arteries
become the anterior inferior, posterior inferior and middle inferior cerebellar arteries.
-supplies blood to the lower portion of the brain
Anterior cerebral arteries
feeds the basal ganglia, corpus callous, and medial surface of the cerebral hemispheres superior frontal and parietal lobes
contralateral paralysis (L) side is most common
L sided infarct R sided weakness
loss of sensation especially in the lower extremities
Middle cerebral arteries
feeds the frontal, parietal, and temporal lobes
aphasia, contralateral paralysis, loss of sensation
Basilar Artery
feeds the pons, medulla, midbrain, corticospinal and corticobulbar tracts, and ocular cranial nerve
quadriplegia, loss of voluntary facial, mouth and tongue movement & loss of horizontal eye movement
“lock-in syndrome”
Posterior cerebral artery
feeds the occipital lobe
vision changes contralaterally
Anterior Inferior Cerebellar Arteries
feed the lateral pons, vestibular nuclei, spinal trigeminal nucleus, cochlear nuclei and sympathetic nerves.
vomiting, vertigo, nystagmus, decreased lacrimation, taste, corneal reflexes, decreased pain and temperature sensation in face and ipsilateral hearing.
Middle and Inferior Cerebellar arteries
feed the cerebellum
ataxia and dysmetria
Dysmetria is a sign of cerebellar damage, and often presents along with additional signs, such as loss of balance and poor coordination of walking, speech, and eye movements. More specifically, dysmetria is a type of cerebellar ataxia, which is the general term used to describe an abnormal coordination of movements.
Posterior Inferior Cerebellar arteries
feeds the lateral medulla, spinal trigeminal nucleus, nucleus ambiguous, sympathetic fibers and inferior cerebellum.
vomiting, vertigo, nystagmus, decreased pain and temperature sensation
ipsilateral face and body, dysphagia, hoarseness, decreased gag reflex, ataxia and dysmetria
