Alvarez- Cerebrovascular disease Flashcards by jorge juarez

___________ in cerebral vessels can respond directly to changes in perfusion pressure
_________ when pressure increases
__________ when pressure drops

smooth muscle

contracts –> ^ pressure
relaxes –> drops

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cerebral blood flow mean arterial pressure range

Higher pressure = ______
lower pressure = _______

60-150 mmHG

edema
ischemia

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how much glucose does the brain consume

brain tissue uses 5.6 mg of glucose per 100g per minute

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Brain vascular features:  (describe)
internal elastic lamina
external elastic lamina
elastic fibers 
adventitia 
endothelial cells (cells that line interior surface of blood vessels)

internal elastic lamina –> well developed
external elastic lamina –> none
elastic fibers –> few in tunica media
adventitia –> very thin
endothelial cells –> not fenestrated (perforations) , have tight junctions critical for BBB)

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CBF (cerebral blood flow) is ____ ml/ min , but not uniform depends on metabolic requirements

750 ml/min

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I think blood
gray matter –> ______ml/(90 or)100g/min
White matter –> ________ml/100g/min

70ml

20-25ml

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how do you calculate cerebral perfusion pressure and what is normal?

mean arterial pressure (MAP) - ICP (intracranial pressure)

normal >70mmHg

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how do you calculate MAP (mean arterial pressure)

MAP= Diastolic BP + 1/3 pulse pressure

usually 90 mmHg

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what is the brains metabolic O2 consumption

3.5 mL/ 100gr of brain tissue

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initial color of an infarcted brain

pale

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within hours to days of a brain infarction (ischemic stroke the gray matter becomes ?

congested with engorged, dilated blood vessels and minute petechial hemorrhages

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en embolus blocking major blood vessels recirculates into infarcted area it can cause a hemorrhagic infarction and may aggravate edema formation due to ?

disruption of the BBB

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During stroke CPP falls casueing

an increase in dilation of cerebral blood vessels

there can be a decrease in CPP beyond the ability for brain to compensate resulting in decreased Cerebral blood flow

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Molecular events during ischemic stroke

<50mL/100g per minute = ________

inhibition of protein synthesis

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Molecular events during ischemic stroke

25mL/100g per minute = ________

protein synthesis ceases completely

Glucose utilization drops drmatically with the onset of anaerobic glycolysis –> tissue acidosis –> accumulation of lactic acid

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Molecular events during ischemic stroke

10-23 mL/100g per minute = ________

variable tissue no function

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Molecular events during ischemic stroke

16-18ml/100g per minute = ________

NEURONAL ELECTRIC FAILURE

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Molecular events during ischemic stroke

10-12 mL/100g per minute = ________

failure of membrane ion homeostasis

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Molecular events during ischemic stroke

<10 mL/100g per minute = ________

irreversible tissue damage

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what is excitotoxicity

brain cells are over excited due to increased Ca++ influx causing activation of proteases and lipases , and formation of free radicals

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80% of strokes are due to __________

20% are due to ______

ischemic cerebral infarction

brain hemorrhage

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two types of edema caused by an ischemic stroke

cytotoxic edema

vasogenic edema

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the faoilre of ATP dependent transport of sodium and calcium ions across the cell membrane resulting in accumulation of water and swelling of brain

cytotoxic edema (casued by stroke)

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increased permeability or breakdown of the brain vascular endothelial cells that make up BBB, allowing macromolecules to enter extracellular space, causing an increased extracellular fluid volume

Vasogenic edema

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Acute ischemic stroke subtypes are often classified in clinical studies using a system called

TOAST trial

what is the difference between thrombosis and embolism

thrombosis --> local in situ obstruction of artery due to disease of arterial wall embolism --> particles or debris originating somewhere else that blocks arterial access to particular brain region

what is systemic hypoperfusion

a more general circulatory problem manifesting itself in brain or other organs

what is the core feature of the onset of ischemic stroke

sudden loss of focal brain function

What artery is involved? (stroke) Motor and sensory deficit (leg > face, arm) grasp, sucking reflexes

anterior cerebral artery

what artery is involved? (stroke) dominant hemisphere:aphasia motor ans sensory deficit (face, arm> leg>foot) Non-dominant --> same body parts

middle cerebral artery

what artery is involved? (stroke) homonymous hemianopia; alexia without agraphia visual hallucinations III nerve palsy, paresis of vertical eye movement

posterior cerebral artery

``` what artery is involved? (stroke) pure motor hemiparesis Pure sensory deficit Pure sensory motor deficit dysarthia/Clumsy hand ```

penetrating vessels

``` what artery is involved? (stroke) Crossed sensory deficits limb and gait ataxia coma bilateral signs suggest what? ```

vertebrobasilar artery suggests artery disease

what artery is involved? (stroke) | progressive stuttering onset of MCA syndrome , occasionally ACA syndrome

internal carotid artery

what does the acronym FAST on the cincinnati prehospital scale mean?

F--> face --> numbness or weakness (especially one sided) A--> arm --> same as ^ S--> speech --> slurred or difficulty T--> time --> time to call 911 if sudden, or accompanied with loss of vision, loss of balance, dizziness or worst headache ever

what is the highest score if the NIHSS

42 each category or ability is rated from 0-4 4 being completely impaired

NIHSS scores meaning | 0=_____

no stroke

NIHSS score | 0-4 =_______

minor stroke

NIHSS score | 5-15 =_______

moderate stroke

NIHSS score | 16-20=_______

moderate to severe stroke

NIHSS score | 21-42 = ________

severe stroke

NIHSS Score over ___________ is considered a contraindication to thrombolytic therapy

what lab studies or tests should be conducted if a patient is suspected of stroke as part of the acute stroke evaluation

noncontrast brain CT or MRI finger stick blood glucose O2 saturation

thrombolytic therapy for acute ischemic stroke should not be delayed while waiting the results of hematologic studies, unless ptt received anticoagulants or suspicion of bleeding or thrombocytopenia/ the only test that is mandatory before initiation of IV ________ is ______

alteplase blood glucose

lowering the systemic BP of patients with acute ischemic stroke has been associated with?

clinical deterioration in observational studies

BP should be stabilized and maintained at or below ___________ for atleast 24 hours after thrombolytic treatment

180/105 mmHG

consensus guidelines suggest what meds as first line antihypertensive agents in stroke ppts

IV labetalol, nicardipine, and clevidipine

For acute ischemic stroke __________ is first line therapy provided that it is given within 4.5 hrs of symptom onset or last time ptt was well

IV alteplase it is time dependent

____________ is indicated for patients with acute ischemic stroke due to large artery occlusion in the anterior circulation and can be treated within 24 hrs of symptoms / even if given alteplase

mechanical thrombectomy

what are the initial goals of treatment for a brain hemorrhage

preventing hemorrhage extension, prevention of secondary injury

Most common etiology of spontaneous ICH?

hypertensive vasculopathy

important cause of primary lobar ICH in older adults. features deposition of congophilic material in small to medium sized blood vessels of the brain and leptomeninges

cerebral amyloid angiopathy

microbleeds or microhemorrhages may be a marker of bleeding prone microangiopathy due to ?

HYALINOSIS (chronic hypertension) or amyloid deposition

In an ICH stupor of coma is an ominous sign except when ?

patients have a thalamic hemorrhage (in which involvement of the reticular activating system is cause of stupor rather than the diffuse brain injury)

ICH location: | hemiplegia, hemisensory loss, homonymous hemianopsia, gaze palsy, stupor, and coma

Putaminal hemorrhage

ICH location: | mild dysarthria, contralateral hemiparesis and sensory

Internal capsule hemorrhage

ICH location: inability to walk due to imbalance, vomiting, headache, neck stiffness, gaze palsy, and facial weakness notably no hemiparesis

Cerebellar hemorrhage

ICH location; hemiparesis, hemisensory loss, and occasionally transient homonymous hemianopsia. There may also be an upgaze palsy with miotic pupils that are unreactive

Thalamic hemorrhage

ICH locations: | These bleeds are associated with a higher incidence of seizures.

Lobar hemorrhage | often affect the parietal and occipital lobes

ICH location medial hemorrhage that extends into the base of the pons. These often lead to deep coma over the first few minutes following the hemorrhage, probably due to disruption of the reticular activating system. The motor examination is marked by total paralysis/ Pin point pupils, abscent horizaontal eye movement, ocular bobbing

pontine hemorrhage

what should the SBP of a patient with an ICH be lowered to according to guidelines

140mmHg optimal (140-160)

what is the most widely studied surgical technique in patients with supretentorial ICH

open craniotomy

for primary regulatory factors of the brain?

cerebral metabolism carbon dioxide and oxygen autorregulation neurohumoral factor

cerebral blood flow maintained at a constant level despite moderate variations in perfusion pressure

cerebral auroregularion

what can be given to patietns who had an ischemic stroke with hemiparesis without depression to enhance motor recovery

SSRI's

gradient echo susceptibility weighted and T2 weighted MRI can detect ?

small regions of focal or multifocal hemosiderin deposition that represent remnants of clinically silent cerebral microbleeds

when are headaches, vomiting, and decreased levels of consciousness caused by hemorrhage most common?

cerebellar and lobar hemorrhages