6 Stroke, part 3

Question 1

Definition of “Onset of Stroke symptoms”

Answer 1

The time the patient was last known well or last known to be at their neurologic baseline

Question 2

Remarks on NIHSS in administration of thrombolytics

Answer 2

A score between 4 and 22 is commonly used.
However, there is no upper or lower limit of NIHSS score for thrombolytics administration as benefit may be seen with both mild but disabling (e.g., aphasia, hemianopia, gait disturbance) a well as in very severe strokes

Question 3

Criteria for rtPA administration for those with onset of symptoms from 3 to 4.5 hours

Answer 3

Age 80 y or below
No history of diabetes mellitus and prior stroke
NIHSS ≤25
Not taking oral anticoagulants
No brain imaging evidence of ischemi injury involving > 1/3 of the MCA territory

Question 4

Some exclusion criteria form thrombolysis in acute ischemic stroke (AIS)

Answer 4

S/s suggestive of SAH
Suspected aortic dissection
Prior ischemic stroke or severe head trauma within 3 months
GI malignancy or GI bleeding within 21 days
—
Platelet <100,000/mm3
INR >1.7 or APTT >40s, or PT >15s
Use of LMWH, direct thrombin inhibitors, or direct factor Xa inh within preceding 48 hours
—
Pretreatment SBP >185 or DBP >110 DESPITE therapy

Question 5

Myocardial infarction and thrombolysis

Answer 5

Acute myocardial infaction is not a contraindication to rtPA

Question 6

Unruptured intracranial aneurysm

Answer 6

An aneurysm <10 mm is NOT a contraindication to rtPA.
rtPA administration with an aneurysm ≥10 mm is controversial

Question 7

As per the WAKE UP trial, these patients may benefit from IV thrombolysis despite the onset time being uncertain

Answer 7

Diffusion-weighted imaging-fluid attenuated inversion recovery mismatch
- acute infarct in diffusion-weighted MRI, but no parenchymal hyperintensity on fluid-attenuated inversion recovery

Question 8

Dosage of IV alteplase in acute ischemic stroke

Answer 8

0.9 mg/kg,
max dose of 90 mg.
administer 10% of the dose as bolus over 1 minute,
with the remaining infused over 60 minutes

Question 9

Dosage of IV alteplase in STEMI

Answer 9

BW >67:
15 mg initial IV bolus, 50 mg infused over next 30 minutes, 35 mg infused over next 60 minutes
(max dose of 100 mg)
BW <67 kg
15 mg initial IV bolus, 0.75 mg/kg infused over next 30 mins, 0.5 mg/kg infused over next 60 mins

Question 10

Dose of tenecteplase

Answer 10

<60 kg: 30 mg
≥60 but <70 kg: 35 mg
≥70 but <80 kg: 40 mg
≥80 but <90 kg: 45 mg
≥90 kg: 50 mg
Max dose of 50 mg
Tenecteplase is given as a single IV bolus over 5-10 seconds.

Question 11

Nicardipine infusion in thrombolysis

Answer 11

Start at 5 mg/hour
titrate up by 2.5 mg/hour at 5- to 15-min intervals
max dose of 15 mg/hour
when desired BP is attained, reduce to 3 mg/hour

Question 12

Nitroprusside infusion in thrombolysis

Answer 12

0.5-10 mcg/kg/min
Continuous arterial monitoring advised
Use with caution in patients with hepatic or renal insufficiency
Increases intracranial pressure
Pregnancy category C

Question 13

Frequency of BP monitoring in thrombolysis

Answer 13

Time after rtPA infusion
0-2 h: every 15 min
3-8 h: every 30 min
9-24 h: every 60 min

Question 14

Risk of orolingual angioedema after alteplase is increased in

Answer 14

Patients taking ACE inhibotrs.
Treat angioedema similarly to other causes of angioedema

Question 15

Endovascular therapy is feasible up to ______ of symptom onset

Answer 15

6 hours

Question 16

AHA/ASA indications for endovascular therapy with a stent retriever

Answer 16

Prestroke mRS score 0 to 1
Acute ischemic stroke receiving IV rtPA within 4.5 hours of onset
Causative occlusion of the ICA or proximal MCA (M1)
Age ≥18 y
NIHSS ≥6
ASPECTS ≥6
Treatment can be initiated (groin puncture) within 6 hours of symptom onset
All 7 criteria need to be met for stent retriever endovascular therapy to be indicated

Question 17

Trials that showed improved functional outcome with thrombectomy even if done for late presenting stroke (>6 hours)

Answer 17

DAWN trial (6 to 24 hours)
Evidence of potentially reversible ischemia via mismatch between clinical symptoms and infarct size
DEFUSE 3 trial (6 to 16 hours)
Evidence of potentially reversible ischemia via penumbra of ≥15 mL

Question 18

Remarks on transient ischemic attack (TIA)

Answer 18

analogous to unstable angina - that is, an ominous harbinger of a potential future vascular event

Question 19

Diagnostics for TIA

Answer 19

Noncontrasted head CT is still the initial imaging study of choice (primarily to rule out stroke mimics)
although it cannot reliably predict risk of subsequent stroke

Question 20

Treatment of TIA primarily focuses on

Answer 20

Prevention of subsequent stroke
CHANCE trial: Aspirin + Clopidogrel = reduces risk of stroke in the first 90 days
POINT trial (Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke, 2018):
A+C = confirmed less recurrent stroke, but higher risk of major hemorrhage at 90 days

Question 21

The risk of hemorrhagic transformation of an acute stroke is greatest when?

Answer 21

in the first 48 hours

Question 22

Anticoagulation in acute ischemic stroke

Answer 22

In the setting of acute atrial fibrillation, anticoaguation is typically should NOT be started in the ED but should be initiated in the inpatient setting

The use of unfractionated heparin, LMWH, or heparinoids for emergent treatment of a specific stroke subset or TIA CANNOT be recommended based on available evidence, even in the presence of atrial fibrillation.

Question 23

Risk stratification scoring system for TIA

Answer 23

ABCD2
Age ≥60 +1
BP ≥140/90 +1
Clinical features (unilateral weakness +2, speech disturbance only +1)
Duration of symptoms (10-59 mins +1, ≥60 mins +2)
Diabetes history +1

Question 24

Interpretation of ABCD2

Answer 24

7-day stroke risk

0-3: low-risk (1%)
4-5: moderate-risk (6%)
6-7: high-risk (12%)

However, “The ABCD2 does not sufficiently identify the short-term risk for stroke to use alone *as a risk-stratification instrument

Question 25

Remarks on MI + AIS

Answer 25

For patients presenting with concurrent AIS and acute MI, treatment with IV alteplase at the dose appropriate for cerebral ischemia, followed by percutaneous coronary angioplasty and stenting if indicated is reasonable.

Do not delay thrombolysis for stroke if the patient qualifies

Question 26

Most common cause of ischemic stroke in children

Answer 26

Sickle cell disease
Treatment includes oxygen, hydration, pain control, and emergent exchange PRBC transfusion with the goal of reducing hemoglobin S levels to <30% and achieve a total hemoglobin level of 10 g/dL (but no higher in order to avoid hyperviscosity)

Question 27

Remarks on strokes in the young adults

Answer 27

age 18 to 50 years
Younger stroke victims have more favorable morbidity and mortality rates after IV thrombolysis, thrombectomy, and decompressive surgery for large MCA strokes.
Therefore, treat these patients aggressively.