Class 4: Vasospasm/Stenosis/Clinical Criteria Flashcards
What is the incidence of cerebrovascular aneurysm ruptures?
It occurs in approx. 30,000 individuals annually.
What is the most common indication for a TCD exam?
SAH.
Subarachnoid Hemorrhage
What is the mortality rate for ruptured cerebrovascular aneurysms?
>50%
what is the percentage of people who develop vasospasm after a cerebralvascular aneurysm rupture?
20-30%
What is the most serious type of aneurysm?
Basilar.
What is the most common type of aneurysm shape?
Saccular.
aka “berry”
Where do subarachnoid hemorrhages typically occur?
In the distal area.
What does the EVD do?
It creates a pressure gradient.
What is the primary cause of cerebral vasospasm?
Cerebral artery anerysm rupture (SAH) or trauma.
What is the theory behind cerebral vasospasm?
The vessel contracts to limit hemorrhage.
What does a prolonged vasospasm lead to?
A stroke.
What does cerebral vasopasm primary affect?
It mainly affects the large cerebral arteries (M1 & M2)
What is the delayed onset of cerebral vasospasm?
2-10 days after bleed (1st week)
When does cerebral vasospasm typically resolve?
2-4 weeks.
What is involved in cerebral vasospasm?
It involves the entire length or a large portion of the vessel.
Difference between vasospasm and stenosis?
Vasospasm→ affects entire length or large portion
Stenosis→ Affects a focal area
What do patients complain of on day #1 of vasospasm?
Worst headache.
When is the peak of vasospasm?
7-10 days
When is the maximum severity of vasospasm?
7-14 days
How long can vasospasm last?
up to 4 weeks.
When does vasospasm usually present when after initial headache?
day 4.
What does the degree of vasospasm depend on?
It depends on the amount of blood.
> RBC= increase vasospasm
<rbc>
</rbc>
What does the vessel affected by vasospasm depend on?
It depends on the location of blood.
What is the main imaging for cerebral vasospasm?
Angiography
What is angiography in relation to cerebral vasospasm?
It is the gold standard for diagnosis of severe vasospasm (insensitive for mild/moderate)
What is the most common screening tool for catching early vasospasm signs?
TCD
What is the goal of TCD?
To identify early development of significant (high/moderate) vasospasm
Wha charactersitics does a vessel in vasospasm have?
It is inflammed and has lumen reduction.
What is the Lindegaard index?
It is a method of correcting for increases in hyperdynamic systemic flow.
What does the Lindegaard index take into account?
MCA mean velocity compared with ipsilateral ICA mean velocity.
LI=MCA/ICA
What is considered hyperemia?
Increased mean velocity & increased LI ratio
What is considered vasospasm?
Increased mean velocity & decreased LI ratio.
What is the MCA vasospasm MFV and ANGIO correlation?
- MFV 120 CM/SEC→ANGIO <25%
- MFV 160 CM/SEC→ANGIO 25-50%
- MFV >200 CM/SEC→ANGIO >50%
What is considered to be mild MCA vasospasm?
120 cm/sec
What is considered to be a moderate MCA vasospasm ?
160 cm/sec
What is considered to be severe vasospasm?
>200 cm/sec
What is the cerebral vasospasm criteria for hyperemia?
Velocity→80-120 cm/sec
Lindegaard Ratio→<3.0
What is the mild cerebral vasospasm criteria ?
Velocity→120-160 cm/sec
Lindegaard Ratio→>3.0
What is the moderate cerebral vasospasm criteria?
Velocity→160-200 cm/sec
Lindegaard Ratio→>3.0
What is the severe cerebral vasospasm criteria?
Velocity→>200 cm/sec
Lindegaard Ratio→>6.0
What is the MFV and ANGIO correlation with BA vasospasm?
- MFV 60 CM/SEC→ANGIO <25%
- MFV 90 CM/SEC→ANGIO 25-50%
- MFV 120 CM/SEC→ANGIO >50%
What is considered to be mild BA vasospasm?
60 cm/sec
What is considered to be moderate BA vasospasm?
90 cm/sec
What is considered to be severe BA vasospasm?
>120 cm/sec
What are two types of endovascular treatments for vasospasm?
- Balloon angioplasty
- Intra-arterial vasodilators
What is the primary cause of ischemic cerebral disease?
Athersclerosis or emboli (from the heart)
What is the gold standard for ischemic cerebral disease?
Angiography
What is involved in ischemic cerebral disease?
It involves a focal portion of the vessel.
What does the patient require with ischemic cerebral disease?
Patient require urgent reperfusion (thrombolysis)
When can TCD be used for ischemic cerebral disease?
TCD can be used to assess acute ischemia (<12 hrs) or reperfusion after IR
What are the characteristics of a cerebral stenosis?
- Bruit
- Tardus parvus
- High resistance
What can TCD assist in?
It can assist in supporting confirmation of cerebral circulatory arrest.
What type of waveform does brain death have?
To-and-Fro.
AKA staccato
What are other test used to confirm brain death?
- EEG
- NMPT
When confirming brain death, what are the primary vessels assessed?
- MCA
- ACA
- BA
What type of pulsatility indices is significant?
High PI
What does a high diastole indicate?
Low PI
What does a low diastole indicate?
High PI
What does a high PI indicate?
- Intracranial athersclerosis
- Increased intracranial pressure
What is sickle cell disease a risk factor for?
It increases the risk for a stroke
What is the TCD’s vital role in sickle cell disease?
Evaluating children as a preventative measure.
How is sickle cell disease treated?
It is treated with blood transfusions.
What is the current approach for all children with sickle cell disease?
- Get baseline TCD as early as possible (usually 2-5 years old)
- Routine annual TCD screenings
What is the primary vessel assessed in sickle cell disease?
MCA
What is considered normal MCA velocity for sickle cell disease?
<170 cm/sec
What is considered borderline MCA velocity for sickle cell?
200-170 cm/sec
What is considered abnormal MCA velocity for sickle cell?
>200 cm/sec
What is patent foramen ovale (PFO)?
It is a right to left shunt.
Blood goes from the right to the left atrium.
(embryologic origin)
What type of test is done to confirm PFO?
HITS study aka bubble study.
TCD preformed with injection of agitated saline mixed with air.
When is PFO confirmed?
When the TCD machine detects HITS while continuously monitoring MCA
What does it mean if there are more HITS detected?
Increased shunt severity
Besides TCD, what other test is used to detect PFO?
Echocardiogram.
What is the primary vessel assed in a HITS study?
MCA
When assessing HITS, what should you have the patient do?
Valvsalva
Where is an aneurysm most common?
Anterior circulation
Where do aneurysms typically occur?
At bifurcations