Definition
A.Temporary blockage of blood flow to the brain (<24 hours) that does not result in permanent damage; often referred to as a mini-stroke.
B.Majority of transient ischemia attacks (TIAs): Complete resolution in less than 10 minutes.
Incidence
A.It is estimated that up to 500,000 people a year have a TIA in the United States.
B.Up to 30% of people who report a TIA have a stroke within 5 years.
C.The incidence of a cerebrovascular accident (CVA) has been reported as high as 11% within 7 days.
Pathogenesis
A.A TIA occurs when there is blockage of blood to the brain from atherosclerosis, any type of emboli, decreased blood flow/volume to the brain, or constriction of the arteries in the brain.
B.The exact symptoms of a TIA correlate with the particular artery that is affected. The hallmark of a TIA is resolution of symptoms within 24 hours from onset.
Predisposing Factors
A.Medical factors.
1.Hypertension.
2.Diabetes.
3.Hyperlipidemia.
4.Coronary artery disease: Arrhythmias, heart defects, heart infections, or valvular disease.
5.Peripheral artery disease.
6.Obesity.
7.Elevated homocysteine levels.
8.Sickle cell disease.
B.Nonmodifiable risk factors.
1.Family history.
2.Age greater than 55 years.
3.Gender (men more likely than women).
4.Prior TIA.
5.Race, with Hispanics and African Americans at higher risk.
C.Lifestyle factors.
1.Cigarette smoking.
2.Physical inactivity.
3.Poor diet.
4.Excessive alcohol intake.
5.Illicit drug use.
6.Oral contraceptive use.
Subjective Data
A.Common complaints/symptoms—the types of complaints a person would have depends on the area of the brain that is affected. In general, there are three main classifications of TIA/CVA based on circulation patterns.
1.Anterior circulation symptoms.
a.Carotid artery: Contralateral motor and sensory loss to arm/leg.
b.Anterior cerebral artery: Confusion, personality changes, motor, or sensory loss in leg.
c.Middle cerebral artery (majority of TIAs/CVAs): Face asymmetry, motor or sensory loss in arm, slurred speech, or aphasia.
2.Posterior circulation symptoms.
a.Contralateral motor or sensory loss.
b.Ipsilateral visual field loss.
c.Cortical blindness.
d.Dysarthria.
e.Dysphagia.
f.Diplopia.
g.Quadriparesis.
3.Vertebrobasilar circulation symptoms.
a.Confusion.
b.Slurred speech.
c.Blurry vision or blindness.
d.Weakness of both arms or legs.
e.Difficulty walking, ataxia.
f.Paresthesias.
B.Common/typical scenario—a typical event is described as happening all of the sudden. One moment the person is fine, the next moment the symptoms occur. In the majority of the cases, the symptoms resolve within 10 minutes and the person is back to his or her previous self.
C.Family and social history.
1.A family history of stroke can raise the risk of stroke, especially if before the age of 65.
2.Smoking, physical inactivity, alcoholism, illicit drug use, and poor diet are all important factors to document.
D.Review of systems—typically all symptoms will have resolved by the time of the interview, but it is important to document which systems were affected.
1.Visual fields—blurry vision, double vision, loss of vision, and/or sense of a curtain being pulled down over one eye (amaurosis fugax).
2.Language—slurred speech, difficulty speaking, inability to find words, and/or inability to understand others.
3.Extremities—weakness, numbness, tingling, and/or strange sensations.
Physical Examination
A.Cranial nerve testing—smile, stick out tongue, raise eyebrows, extraocular movements, and/or visual fields.
B.Motor strength.
C.Sensory testing.
D.Gait and posture—walking heel to toe and/or finger to nose test.
Diagnostic Tests
A.CT head.
B.MRI brain within 24 hours.
C.Carotid Doppler—to assess for carotid disease.
D.ECG—to assess for atrial fibrillation.
E.Transthoracic echocardiogram (TTE) to rule out any cardioembolic source.
F.Lab tests—glucose, chemistry profile, lipid panel.
1.Consider hypercoagulable workup if younger than 40 years of age or based on history.
2.Consider alcohol levels based on history.
Differential Diagnosis
A.Ischemic stroke.
B.Hemorrhagic stroke.
C.Migraine.
D.Bell’s palsy.
E.Seizure.
F.Hypoglycemic/hyperglycemia episode.
G.Sepsis.
H.Vertigo.
I.Neuromuscular or neurodegenerative disease.
J.Brain tumor.
K.Meningitis.
L.Syncope.
Evaluation and Management Plan
A.General plan.
1.Obtain results from diagnostic tests.
2.Prevent further stroke from modification of risk factors.
3.Manage blood pressure.
4.Initiate lipid control.
5.Maximize blood glucose control.
B.Patient/family teaching points.
1.Assess family baseline understanding of TIAs/CVAs.
2.Educate on risk factor modification.
3.Educate on the role of diet/exercise in preventing future TIAs/CVAs.
4.Educate on role of pharmacotherapy and adverse effects.
5.Provide pamphlets and educational materials.
6.Introduce smoking cessation plan if indicated.
7.Introduce weight loss program if indicated.
C.Pharmacotherapy.
1.Antiplatelet drugs—low dose aspirin or clopidogrel should be initiated as soon as intracranial hemorrhage has been ruled out.
a.Aspirin 81 to 325 mg.
b.Clopidogrel.
2.Anticoagulants—prescribed only if there is an increased cardioembolic risk as determined by the CHA2DS2-VASc Score (see Table 6.4).
3.Thrombolytics—not indicated if there is resolution of symptoms.
D.Surgical intervention.
1.Carotid endarterectomy if person is symptomatic with severe carotid stenosis (70%–99% blockage).
E.Discharge instructions.
1.Warning signs of stroke.
2.What to do if person suspects a stroke: Call 911.
3.Possible Medic Alert bracelet if taking a blood thinner.
Follow-Up
A.Follow-up with primary care provider within 2 weeks.
Consultation/Referral
A.Refer all patients to neurology team.
TABLE 6.4 CHA 2 DS 2 -VAS c Score Criteria
Note: 0 points: No need for antiplatelet or anticoagulants; 1 point: None OR aspirin OR anticoagulant, depending on situation; ≥2 points: Start anticoagulant.
CVA, cerebrovascular accident; MI, myocardial infarction; TIA, transient ischemic attack.
Source: Lip, G. Y., & Halperin, J. L. (2010, June). Improving stroke risk stratification in atrial fibrillation. American Journal of Medicine, 123(6), 484–488. doi:10.1016/j.amjmed.2009.12.013
Special/Geriatric Considerations
A.Hypercoagulopathy can occur secondary to cancer, pregnancy, and in sickle cell disease. Patients under the age of 40 who present with TIA should undergo a hypercoagulable workup.