Transient Ischemic Attack Flashcards
TIA
sudden onset of focal neurologic deficits is secondary to disturbance of cerebral circulation
TIA locations?
carotid or vertebral vascular distribution
how long do sx last?
sx should resolve completely w/in 24 hours
sx of carotid circulation ischemia
contralateral hand-arm weakness w/ sensory loss, ipsilateral visual sx or aphasia, or amaurosis fugax
sx of vertebrovascular
diplopia, ataxia, vertigl, dyarthria, cranial nerve palsie, lower extremity weakness, dimness or blurring of vision, perioral numbness, drop attacks
what is the definitive dz of TIA?
arteriography, but MRA also used and is less invasive
what other things need to be looked up?
- cardiac work up (arrhythmias and new murmurs)
- hematologic- exclude coagulopathies
- CBC w/ diff, cholestrol, PTPTT, antiphospholipids
- ESR: r/o temporal arthritis
tx of TIA if not cardiogenic
ASA, ticlopidine, clopidogrel, dipyridamole, sulfinpyrazone
cardiogenic TIA
requires anticoagulants
IV Heparin for those who are admitted to the hospital
when would you need a carotid endarterectomy
indicated in pts w. anterior circulation TIAs and moderat to high-grade carotid stinosis on the side appopriate to account for the sx
Cerebral Vascular Accident
stroke is the 3rd most common cause death, and the most in US
what are major RF for CVA?
HTN, hypercholesterolemai, DM, oral contraceptives, cigarette smoking , AIDS, elevated blood homocysteine levels
homocysteine
higher levels can make a person more prone to endothelial injuries, which leads to inflammation of the blood vessels, etc. etc ishemic injuresi
Ischemmic strokes
80% of all
1/3 embolic
2/3 thrombotic
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where do embolie usually arise from?
heart, aoric arch, large cerebral ateries
hemorrhagic strokes
secondary to HTN, account for 20% o fall strokes
CF s/s of a stroke
begine abruptly, and last longer than 24 hours
-correlate w/ the area o fhe brain that is supplied by the affected vessel
how do you tell what side of the brain is affected?
contralateral fo the hemiparesis or hemisensory deficits
anterior circulation strokes
- anterior choroidal, anterior cerebral, middle cerebral ateries
- cortex, subcortical white matter, basal ganglia, internal capsule,
- aphasia, apraxia, hemiparesis, hemisensory losses, visual field defects
postereior circulation
- verrebral and basilar arteries
- brainstem, cerbeullum, thamlamus, portions of the temporal and occipital lobs
-coma, drop attacks, verigo, N, V, ataxia
features of thrombotic strokes
stepwise fasion, often preceded by TIAs
-embolic strokes occure abruptly and w/o warning
hemorrhagic stroke features
less predictable bc of complication of blood disersion, cerebral edema, increased intracranial pressure
lab studies storke
- CBC, ESR, platelet counts, PT, PtTT, cholesterol, lipids, and blood glucose level
- VDRL test for syphilis
imaging stroke
CT- best for ischemic vs heorrhagic
tx for stroke
thrombolytic therapy
- most effect 3 hours after sx, but can be attempted up to 12 hours
recombinant tissue plasminogen activator
CI for TpA
evidence or suspicion of intracranial bleed
- recent intracranial sx,
- serious head trauma or previous stroke
- hx of intracranal bleed
- uncontrolled HTN (> 185/110)
- sz at stroke onset,
- active internal bleed
- intracranial neoplasm
- AVM or aneurysm
- heparin use w/ in 48 hours
- platelet coutn <100000
tx for ischemic stroke?
antiplatelet therapy
tx for cardicac embolus
anticoag
when is an endarterectomy indicatd in stroke?
70-99 % stenosis of the common or internal caroti artery
how do you manage HTN in a stroke?
mannitol or corticosteroids
-IV labetaolo and nicardipine
can use nitroprusside ads 2cd line therapy (this is alos good for aortic discsection)
pre hospital care of a stroke victime
O2
IV NS if hypotensive
if BS < 60, give IV glucose to see if neuro sx resov
what are some ex of stroke mimics?
- psychogenic
- seizures
- hypoglycemia
- migraine w/ aura
- hypertensive encephalpathy
- Wernickes’ encephalopaty
- CNS abscess
- CNS tumor
- drug toxicity (Lithium, phenytoin, carbamazepine)
what is rtPA?
Alteplase IV r-tPA is given through an IV in the arm, also known tPA, and works by dissolving the clot and improving blood flow to the part of the brain being deprived of blood flow.
what is the inclusion criteria for rtPA?
Diagnosis of ischemic stroke causing measurable neurological deficit
Onset of symptoms within 3 to 4.5 hours before beginning treatment
what are relative CI for the use or rtPA?
Aged >80 years
Severe stroke (NIHSS>25)
Taking an oral anticoagulant regardless of INR
History of both diabetes and prior ischemic stroke
what other drugs does a pt need to be put on after having a stroke?
- ASA
- prophylaxis for DVT or PE ( lovenox)
- antithrombotic therapy at discharge
- statin
- BP reduction
what are types of brain ischemia?
focal (territorial or local) and global
what is focal ischemia due to?
Due to occlusion of a blood vessel
Produces infarct within territory of occluded vessel
Atherothrombosis, intra-arterial (artery-to-artery) emboli, and cardiogenic emboli are usual causes of arterial occlusion
what is global ischemia due to?
cardiac arrest, systemic hypotension, or increased inctracranial pressure
=causese widepread, ischemic necrosis that may be accentuated or limited to watershed zones
where are most berry aneurysms found at?
forks of arteries at the base of the brain
antierior communicating artery
what is a arteriorvenous malformation?
tangle of abnormal arteris and veins w/ no interveing capillary bed
-can rupture
involves brain and leptomeninges
what are some common causes of brain hemorrhages?
- Hypertensive small-vessel disease
- Cerebral amyloid angiopathy
- Ruptured vascular malformation
- Ruptured berry aneurysm
- Neoplasm
- Bleeding diathesis
- Trauma
- Drugs (cocaine, amphetamines)
what are the clinical features of a large MCA infarct?
middle cerebral artery
- Contralateral weakness and sensory loss
- Visual field abnormality (homonymous hemianopia)
- Language disturbance or spatial perception problem (depending on the cerebral hemisphere involved)
what is the most common artery affected by a CVA?
the MCA
what does the MCA supply?
the outer convex brain surface, nearly all the basal ganglia, and the posterior and anterior limb of the internal capsules.
symptoms of a postereior circulation (vertebrobasilar) ischemia?
- double vision (dioplopia, bionocular graying, clouding, blurring, or loss of vision
- vertigo,
- unilater or bilateral weakness, clumsiness, or numbness in limbs
- areticualroy or swallowing distrubances
- lack of coordination or staggering
what does the term anterior circulation refer to?
branches of the internal carotid artery (MCA and ACA)
what does the term posterior circulation refer to?
vertebral-basilar arterial tree and its brances including the PCA
what is broca’s aphasia
damage to the motor association cortex in left frontal lobe. Comprehension preserved but language output is impaired and non-fluent
Wernicke’s aphasia?
damage to left temporal lobe (posterior). Comprehension is severely impaired, while language is fluent.
what is dysarthria?
a condition in which the muscles you use for speech are weak or you have difficulty controlling them. Dysarthria often is characterized by slurred or slow speech that can be difficult to understand
what are some causes of large extracranial vessle pathologies?
atherosclerosis cervical artery dissection takayasu arteritis giat cell arteritis fibromuscular dysplasia
what are some causes of large intracranial vessel pathologies?
atherosclerosis intracranial artery dissection arteritis/vasculitis noninflammatory vasculopathy moyamoya sx
cortical stroke sx?
Often are large vessel territory infarcts if are not embolic
If occur on pt.’s language center (hemisphere opposite dominant hand) can have aphasia. –usually its Left side dominant)
agraphia, acalculia, neglect (most common-they just cant see you on a certain side), trouble with visuo/spatial, memory/behavior, gaze preference, or trouble with higher order cognitive function also present
Motor / Sensory Involvement:
Focal motor weakness, Face/Arm > Leg or Leg > Face/Arm
Focal sensory loss
what is astereogenosis
loss of ability to recogize objects by touchd
subcortical stroke area?
Internal Capsule / Basal Ganglia / Thalamus
Often caused by lacunar infarcts
what are CF of subcorktcal stroke?
predominately motor or sensory deficits (Face = Arm = Leg) on the opposite side of the body
Extraocular muscle impairments Other cranial nerve findings (facial paresthesias, facial weakness, bulbar symptoms) Diplopia Dysphagia Dysarthria Nystagmus
what could a thalamic strock cuase?
hemibody sensory deficit often painful after recovery “thalamic pain syndrome”
what do brainstem strokes mostley involve?
the posterior circulation-basilar artery, vertebral arteries, and or cerebellar arteris
what do pts present with in a brainstem stroke?
nausea/vomiting/headache/double vision/imbalance/ and eye movement problems / other cranial nerve deficits
what about cerebellar strokes?
often similar to brain stem syndromes
-gait imbalance
-ataxia
N
V
vertigo
tremor
nystagmus
hypoperfusion sx of ishemci stroke?
pts will have circulatory problems (hypotension, pallor, sweating, tachycardia, bradycardia, hypotension)
Bilateral symptoms for the most part
what are sx of watershed ischemis?
cortical blindness, bilateral vision loss, coma, weakness of shoulders/thighs spare face/hands/feet “man in a barrel”
what is the gold standard for stroke?
MRI bc it can adentify ischmia acutely
what are the three main types of TIA?
large artery, low flow
emboli
lacunar
what are the main causes of large artery, low flow TIA
- brief, recurrent, and sterotyped due to vessel it effects
- stenotic internal carotid, middle cerebral, or vertrebral-basilar junction
what are the main causes of lacunar or small vessle tia?
stnosis of intracerebral penetrating vessels from MCA, basilar or vertebral areires. hTN and DM II are the main culprits
