Stroke Flashcards
The MCA supplies these eloquent functional areas of the brain:
So, if your pt had a massive stroke at the base of the MCA, they could experience:
::Primary sensory and motor for the head, neck, and arms.
::Frontal eye field- for non-tracking eye movement via PPFR.
::Brocas/Wernicke’s areas
::Optic radiations
::Internal Capsule
MCA stroke: contralateral hemiparesis and hemiparesthesia (internal capsule stroke), loss of voluntary eye movements, loss of speech and language abilities, loss of vision in the contralateral eye fields.
The ACA supplies these eloquent functional areas of the brain:
So, if your pt had a massive stroke at the base of the ACA, they could experience:
::Mid-saggital region- trunk and lower extremities.
::Parietal lobe
Contralateral hemiparesis below the neck +/- upper arms due to shared ACA/MCA watershed.
The PCA supplies these eloquent functional areas of the brain:
So, if your pt had a massive stroke at the base of the PCA, they could experience:
Medial occipital lobe, thalamus, hippocampus, corpus callosum, cerebral peduncles.
Loss of vision in contralateral eye fields, lethargy, coma, memory loss, loss of hand-eye coordination, alexia, alexia w/o agraphia, loss of color vision (lingual gyrus), contralateral motor dysfunction due to loss of cerebral peduncle.
What is a lacunar stroke?
What deficits would a pt w/ lacunar stroke experience?
Lacunar stroke or lacunar infarct (LACI) is a type of stroke that results from occlusion of one of the penetrating arteries that provides blood to the brain’s deep structures.
Pure hemiparesis/hemisensory deficits
Ataxia hemiparesis
Dysarthria-Clumsy hand syndrome
MCC of cardiogenic stroke?
Afib
1 risk factor for stroke?
Hypertension.
Purely bc hypertension is so common. Afib is the most dangerous condition predisposing to stroke, per capita. I.e., if you have Afib, you are more likely to have a stroke than if you have HTN, but because so many damn ppl have HTN, it is the most common cause of stroke.
You have how many minutes of glucose reserves available in your brain parenchyma?
2.5 mins
You want to normalize these two elements in stroke pts to prevent exacerbation of their ischemic injury upon reperfusion.
Glucose and temperature.
Drop temperature and normalize glucose.
Explain the terms ischemic core and penumbra in terms of how long it takes cells there to start dying after ischemia.
Core: tissue dies in
What is the stroke intervention time frame? (give an answer in hours)
4-6 hrs
Give the definition of cerebral blood flow in terms of mean arterial pressure and cerebral vascular resistance.
CBF = MAP/CVR
In healthy individuals, CBF is constant between MAP of:
Why is this necessary, physiologically?
55-155 mmHg
Allows for constant CBF when changing body positions.
Describe the relationship between CBF and MAP at the extremes of MAP.
Very high MAP, CBF very high = hypertensive encephalopathy
Very low MAP, CBF very low = ischemia
The lateral medulla receives its blood supply from these major vessels:
Loss of blood supply from these arteries leads to Wallenberg Syndrome, characterized by:
VA and PICA
Medullary Stroke Syndrome (Wallenberg Syndrome)
xSpinal nucleus tract of V- v pain/temp from ipsilateral face
xSpinothalamic tract- loss of pain/temp from contralat. body
xSpinocerebellar tract- gait ataxia
xVestibular nuclei- nystagmus, vertigo
xIpsilateral descending sympathetics- Horner’s syndr.
xNucleus ambiguous- dysarthria, dysphagia (can’t talk, swallow bc loss of vagus)
The medial pons receives its blood supply from these major vessels:
Loss of blood supply from these arteries leads to Medial Pontine Syndrome, characterized by:
Basilar arteries, posterior/lateral supply by SCA
xCST- contralateral hemiparesis (rostral to decussation)
xPontine nuclei- contralateral cerebellar symptoms
xMedial lemniscus- contralateral fine touch/proprioception
xMLF/PPRF- can’t turn eye medially to look at contralateral eye field
The midbrain receives its blood supply from these major vessels:
Loss of blood supply from these arteries leads to Benedikt Sydrome, characterized by:
PCA
Midbrain Stroke Syndrome (Benedikt Syndrome)
xCN III- Ipsilateral CNIII paresis (down/out w/ loss of constriction)
xMedial lemniscus- contralateral fine touch/proprioception
xRed nucleus- contralateral ataxia and tremor of arms.
Anterior circulation includes these major vessels and leads to these deficits:
ICA, MCA, ACA
::Ipsilateral blindness- l/o Opthalmic artery
::Contralateral inferior quadrantopsia- l/o parietotemporal branches of MCA
::Contralateral gaze paresis
Contralateral mono/hemiparesis and sensory defecit.
Aphasia (dominant side), neglect (non-dominant side)
Posterior circulation includes these major vessels and leads to these deficits:
PCA, SCA, AICA, PICA, VA, BA
::Crossed face weakness/sensory deficits- l/o CN V, VII
::Contralateral hemianopsia, superior quadrantanopsia- l/o PCA
::Vertigo, ataxia, dysphagia, Horner’s, diplopia- l/o CN VI, VIII, IX, X, sympathetics due to occlusion of VA/PICA (Wallenberg- Medullary Stroke)
Altered consciousness/amnesia- l/o thalamus w/ xPCA, SCA, AICA
Compared to ischemic stroke, hemorrhagic stroke is less common, only accounting for ____% of all strokes identified.
These are further subdivided into intracerebral hemorrhage and subarachnoid hemorrhage, each accounting or ___% of hemorrhagic strokes.
20%
ICH: 50% - into brain
SAH: 50% - around brain
On CT, expect these findings in an SAH:
blood filling sulci
On CT, expect these findings in an ICH:
incr. density of parenchyma
On CT, expect these findings in an epidural hemorrhage:
Due to arterial origin in epidural space, look for more rounded hematoma, compressing brain sharply. VERY DANGEROUS, KILLS QUICKLY!
On CT, expect these findings in a subdural hemorrhage:
Due to venous origin of bleed in subdural space, look for broad compression of brain. Most small SDH clot off and resolve on their own, but larger ones can KILL SLOWLY, esp in pts on blood thinners!
Pt bursts an aneurysm. They will have a bleed in this space:
SAH (watch out for vasospasm!) **Worst headache of life!
Pt hit in the pterion with a hammer. They will have bleeding in this space:
Epidural (fix surgically NOW!)
Pt falls and hits back of head. They tore bridging vessels in this space, leading to a slow, but potentially dangerous bleed:
Subdural space. GET CT
MCC of intracerebral hemorrhage:
Trauma > HTN > AVMs (arteriovenous malformations)
Location of MC bleeds due to HTN assoc. microaneurysms (Charcot Bouchard aneurysms):
Basal ganglia > thalamus > cerebellum > pons
Pt has a 2mm aneurysm. What is the prognosis?
This is very common- found in 20% of gen pop. Prop will not bleed.
Pt has a >5mm aneurysm. What is the prognosis?
Not so common in population. More likely to rupture.
The best time to do an LP to look for SAH is:
4-6 hrs after onset of symptoms. By that time, RBCs would have lysed, releasing contents that will be picked up on analysis.
SAH is known to cause arrhythmias. Why is this?
Lysed RBC contents irritate the cardiac center of the brain (stem?)
Pt had a hemorrhagic stroke and lost control of lower legs. Where is the stroke?
ACA
Pt has a hemorrhagic stroke and is experiencing hemiparesis. Where is the stroke?
Contralateral MCA
Pt has dilated pupils and opthalmoglegia. Where is the aneurysm?
Berry aneurysm at junction of PCA and PCOM.
What percentage of pts w/ aneurysm rupture survive that particular episode?
40%
Does xanthochromia mean you nicked a vein getting the LP or there was an SAH?
SAH! Xanthochromia is Hb breakdown product
Acute tx of stroke @
intraVENOUS tPA
Acute tx of stroke @ >4.5 but
intraARTERIAL tPA
Acute tx of stroke @ >6 but
retrieve clot w/ intraarterial device.
