Ischemic Stroke

Question 1

What is the timing of symptoms of stroke like?

Answer 1

Symptoms which achieve maximal intensity within seconds to minutes of onset and simultaneously affect multiple different systems at once are typical of stroke.

Question 2

What are stroke risk factors?

Answer 2

Stroke risk factors include hypertension, diabetes, hyperlipidemia, tobacco abuse, advanced age, atrial fibrillation or prosthetic heart valve, and prior stroke.

Question 3

What is the single most important part of the history?

Answer 3

The single most important component of the history is the exact time of onset of symptoms.

Question 4

PE should include

Answer 4

This should include assessment of level of consciousness, cranial nerves, strength, sensation, cerebellar function and gait.

Question 5

What scale can you use to diagnose risk for stroke?

Answer 5

NIH scale:
0 Normal
1-4 Minor
5-15 Moderate
15-20 Moderately Severe
> 20 Severe

Question 6

Common stroke symptoms of ACA

Answer 6

ACA: unilateral weakness and/or sensory loss of contralateral lower extremity greater than upper extremity

Question 7

Common stroke symptoms of MCA

Answer 7

MCA: unilateral weakness and/or sensory loss of contralateral face and upper extremity greater than lower extremity with either aphasia (if dominant hemisphere) or neglect (if non-dominant hemisphere)

Question 8

Common stroke symptoms of PCA

Answer 8

PCA: unilateral visual field deficit in both eyes (homonymous hemianopsia).

Question 9

Common stroke symptoms of Vertebrobasilar syndromes

Answer 9

Vertebrobasilar syndromes have multiple deficits which typically include contralateral weakness and/or sensory loss in combination with ipsilateral cranial nerve palsies. Suspicion for posterior circulation stroke is heightened if the patient exhibits one of these signs or symptoms beginning with “D”: diplopia, dysarthria, dysphagia, droopy face, dysequilibrium, dysmetria, and decreased level of consciousness. Nausea and vomiting are also frequently associated with brainstem stroke.

Question 10

Common stroke symptoms of lacunar infarcts

Answer 10

Lacunar infarcts are small strokes (measuring less than 1.5 cm) caused by occlusion of one of the deep perforating arteries which supplies the subcortical structures and brainstem. Lacunar infarcts can produce a large variety of clinical deficits depending on their location within the brainstem and have been characterized by more than 70 different clinical syndromes. However, the vast majority of lacunar strokes are described by the 5 most common lacunar syndromes: pure motor hemiparesis, sensorimotor stroke, ataxic hemiparesis, pure sensory stroke, and dysarthria-clumsy hand syndrome.

Question 11

Guidelines for Initial Evaluation and Treatment of Acute Stroke in the Emergency Department

Answer 11

Door to physician: 10 minutes
Door to stroke team: 15 minutes
Door to lab work completed: 45 minutes (CBC, BMP, PT/PTT, UA, EKG, CXR)
Door to non-contrast CT-head ordered: 25 minutes
Door to CT interpretation: 45 minutes
Door to decision to give tPA: 45 minutes
Door to drug administration: 60 minutes (and less than 3 hours from onset)
Door to admission: 180 minutes

Question 12

What imaging do you need to get first when worried about a stroke?

Answer 12

Head CT without contrast should be performed on all patients to exclude intracranial hemorrhage.

Question 13

What is the most common finding in patients with stroke with CT?

Answer 13

most common CT finding in acute ischemic stroke is normal brain. Can take hours for changes to be seen on CT.

Question 14

What is the earliest findings seen on CT?

Answer 14

• The earliest finding that may be seen on CT is hyperdensity representing acute thrombus or embolus in a major intracranial vessel.
• Subsequent findings include subtle hypoattentuation causing obscuration of the nuclei in the basal ganglia and loss of gray/white differentiation in the cortex.
• Frank hypodensity on CT is indicative of completed stroke and may be a contraindication to thrombolytic therapy (see below).

Question 15

What is the FDA only approved therapy for stroke?

Answer 15

Intravenous recombinant Tissue Plasminogen Activator (rtPA) is currently the only FDA-approved therapy for acute ischemic stroke. rtPA is a fibrinolytic agent that catalyzes the conversion of plasminogen to plasmin, the major enzyme responsible for clot breakdown. Treatment with IV rtPA has been shown to increase the percentage of patients with good functional outcome at 3 months and 1 year after stroke onset.

Question 16

When must you use tPA by?

Answer 16

rtPA has been FDA approved for use up to 3hrs after symptom onset. In addition, the American Heart Association has recommended rtPA for use up to 4.5 hours after symptom onset in a select subgroup of patients. Good functional outcomes are most likely to be achieved if rtPA is administered within 90 minutes of symptom onset.

Question 17

What is the major complication of rtPA?

Answer 17

The major complication of rtPA administration in stroke is symptomatic intracranial hemorrhage.

Question 18

Inclusion criteria for rtPA?

Answer 18

Inclusion criteria:

• Diagnosis of ischemic stroke causing measurable neurological deficit
• Onset of symptoms < 3 hours before beginning treatment
• Aged ≥18 years

Question 19

Exclusion criteria for rtPA?

Answer 19

• Significant head trauma or prior stroke in previous 3 months
• Symptoms suggest subarachnoid hemorrhage
• Arterial puncture at noncompressible site in previous 7 days
• History of previous intracranial hemorrhage
• Intracranial neoplasm, arteriovenous malformation, or aneurysm
• Recent intracranial or intraspinal surgery
• Elevated blood pressure (systolic >185 mm Hg or diastolic >110 mm Hg)
• Active internal bleeding
• Acute bleeding diathesis, including but not limited to
  Platelet count <100 000/mm³
  Heparin received within 48 hours, resulting in elevated aPTT greater than the upper limit of normal
• Current use of anticoagulant with INR >1.7 or PT >15 seconds
• Current use of direct thrombin inhibitors or direct factor Xa inhibitors with elevated laboratory tests
• Blood glucose concentration <50 mg/dL (2.7 mmol/L)
• CT demonstrates multilobar infarction (hypodensity >1/3 cerebral hemisphere)

Question 20

Relative exclusion criteria?

Answer 20

• Only minor or rapidly improving stroke symptoms (clearing spontaneously)
• Pregnancy
• Seizure at onset with postictal residual neurological impairments
• Major surgery or serious trauma within previous 14 days
• Recent gastrointestinal or urinary tract hemorrhage (within previous 21 days)
• Recent acute myocardial infarction (within previous 3 months)

Question 21

What should blood pressure be controlled below if they received rtPA?

Answer 21

Blood pressure should be maintained below 180/105 mm Hg in the first 24 hours after receiving thrombolytic therapy.

Question 22

What is permissive HTN if patient does not receive rtPA?

Answer 22

220/120 mm Hg.

Question 23

When is Aspirin recommended in stroke patients?

Answer 23

In stroke patients not receiving rtPA, oral administration of aspirin within 24 – 48 hours of stroke onset is recommended.