Transient Ischemic Attack
Cheryl A. Glass
Definition
A.Transient ischemic attack (TIA) are brief focal brain deficits or spinal cord or retinal ischemia (without acute infarction) caused by vascular occlusion. TIAs are a medical emergency.
Symptoms generally last less than an hour; however, they may have permanent sequelae. TIAs are a risk factor for recurrent risk of stroke. Approximately 15% of diagnosed strokes are preceded by TIAs. TIAs can be difficult to diagnose because symptoms are transient. Assume that all stroke-like symptoms signal an emergency.
B.Persistence of neurologic deficit suggests a stroke rather than a TIA.
Incidence
A.The prevalence of TIAs in the United States is between 200,000 and 500,000 per year. The population prevalence is about 2.3% or about five million Americans.
B.The early risk of stroke is approximately 5% at 2 days and as high as 11% at day 7 after a TIA.
C.The risk of a stroke within 3 months of a TIA is 10% to 15%.
D.More than one-third of those who have a TIA will have a major stroke within a year if risk factors are not addressed.
E.The risk from death from coronary artery disease and stroke is as high as 6% to 10%, depending on other risk factors.
F.More men (101/100,000) than women (70/100,000) are affected. There is an increased number of Black adults with TIAs (98/100,000) than White adults (81/100,000) affected by TIAs.
Pathogenesis
A.The pathogenesis is a neurologic event secondary to a temporary reduction of blood flow to the brain from a partially occluded vessel or related to an acute thromboembolic event.
Predisposing Factors
A.Hypertension (HTN):
1.Systolic blood pressure greater than 140 mmHg.
2.Diastolic blood pressure greater than 90 mmHg.
B.Atherosclerosis.
C.African American.
D.Age older than 40 years.
E.Hypotensive episodes.
F.Oral contraceptives/hormone therapy (HT).
G.Atrial fibrillation (AFib).
H.Smoking.
I.Familial hyperlipidemia.
J.Diabetes mellitus (DM).
K.Valvular heart disease.
L.Infective endocarditis.
M.Migraine with aura.
N.Herbal medications alter bleeding time and interact with warfarin:
1.Feverfew.
2.Garlic.
3.Ginkgo biloba.
4.Ginger.
5.Ginseng.
Common Complaints
Signs and symptoms depend on the affected vessel and surrounding brain tissue.
A.Acute onset of focal neurologic deficit:
1.Limb weakness or numbness.
2.Facial weakness.
3.Speech difficulty to aphasia.
4.Visual loss/blurring.
5.Ataxia.
B.Acute change in level of consciousness (LOC) or confusion.
C.Posterior circulation TIAs may have a headache as one of the prodromal symptoms that precedes a stroke by days or weeks.
D.Basilar artery occlusion TIAs have vertigo, nausea, and headaches that may occur as early as 2 weeks or more prior to the onset of stroke.
Other Signs and Symptoms
A.Dysarthria.
B.Dysphagia.
C.Near syncope.
D.Hemiparesis.
E.Temporary monocular blindness.
F.Behavior changes.
G.Difficulty with balance and vertigo.
H.Dizziness.
I.Diplopia.
Subjective Data
If a TIA is suspected, call 911; symptoms from a TIA and a major stroke are not always distinguishable.
A.Ask detailed questions about symptoms before, during, and after the spell:
1.Review the exact timing of onset of symptoms.
2.How intense were the symptoms?
3.What was the duration of any fluctuation of symptoms?
4.Has there been a pattern that is becoming more frequent or escalating in symptoms?
B.Interview the patient, family members, witnesses, and emergency personnel for their description of behavior, speech, gait, memory, and movement.
C.Focus on precipitating factors and state of consciousness after the acute event.
D.Question the patient about risk factors such as HTN, smoking, cardiac disease, and heredity.
E.Review all medications, including anticoagulants, over-the-counter (OTC), and herbals and illicit drug use such as cocaine.
F.Review the medical history:
1.Recent surgeries, specifically carotid or cardiac surgeries.
2.Seizures.
3.Central nervous system (CNS) infection.
4.Illicit drug use.
5.Presence of any metabolic disorders.
6.Recent trauma (blunt or torsion injury to the neck).
7.AFib.
8.Migraine headaches.
Physical Examination
A.Check temperature (if infectious process is suspected), pulse, respirations, and blood pressure, including orthostatic blood pressure, as well as pulse oximetry.
B.General observation:
1.Observe overall appearance, LOC, ability to interact, language, difficulty swallowing, tremors, and spasticity, as well as memory skills.
2.Observe the patient walking (cerebellar system).
C.Inspect:
1.Dermal exam:
a.Overall hydration status.
b.Look for postcarotid endarterectomy scars, presence of a pacemaker, implantable cardioverter defibrillator, or other cardiac surgical scars.
2.Check pupil size and reactivity to light.
3.Perform a fundoscopic exam to evaluate optic disk margins, retinal plaques, and pigmentation.
D.Auscultate:
1.Heart for rate, rhythm, murmurs, or rubs.
2.Lungs: Note respiratory rate and pattern.
3.Carotid arteries for the presence of bruit.
E.Palpate:
1.Palpate extremities for pulses and peripheral edema.
F.Neurologic exam:
1.Cranial nerve (CN) testing:
a.Wrinkle forehead/raise eyebrows.
b.Smile and show teeth.
c.Stick out the tongue/lateral tongue movement.
d.Ocular movements.
e.Visual field.
2.Motor strength:
a.Shrug shoulders.
b.Test muscle strength: Grasp hands and squeeze.
c.Check reflexes of biceps, triceps, patellar, brachioradial, and Achilles.
3.Sensory testing: Pinprick.
4.Gait and posture (cerebellar system evaluation):
a.Ocular movements.
b.Gait.
c.Finger-to-nose test.
d.Heel-to-knee test.
Diagnostic Tests
A.Pulse oximetry.
B.Laboratory tests:
1.Emergent labs:
a.Glucose.
b.Serum chemistry profile, including creatinine.
c.Coagulation and hypercoagulability testing.
d.Complete blood count (CBC).
2.Urgent labs:
a.Erythrocyte sedimentation rate (ESR).
b.Cardiac enzymes.
c.Lipid profile.
3.Other laboratory tests based on history:
a.Urine drug screen.
b.Blood alcohol level.
c.Antiphospholipid antibodies.
d.Rapid plasma reagin (RPR) for syphilis.
C.MRI or CT scan within 24 to 48 hours of symptom onset.
D.Carotid Doppler ultrasonography identifies patients with urgent surgical needs.
E.Cardiac imaging to evaluate cardioembolic sources.
F.ECG to evaluate dysrhythmias (i.e., AFib).
G.Lumbar puncture (LP) to rule out infection, demyelinating disease, and subarachnoid hemorrhage (SAH).
H.EEG as indicated for seizure activity.
I.Consider Holter monitor for suspected intermittent AFib.
Differential Diagnoses
A.TIA.
B.Ischemia stroke.
C.SAH/subdural hematoma.
D.Migraine.
E.Hypoglycemia/HTN.
F.Epilepsy-postictal period.
G.Malignant HTN.
H.Brain tumor.
I.Bell’s palsy.
J.Multiple sclerosis (MS).
K.Syncope.
L.Drug induced.
M.Concussion.
N.Vertigo.
Plan
A.General interventions:
1.Carefully assess the patient to timely diagnose TIA.
2.Perform a full workup to determine the underlying disease process.
3.Prevent stroke by modification of risk factors.
B. 
See Section III: Patient Teaching Guide Transient Ischemic Attack.
C.Medical and surgical management:
1.Treat TIAs with antiplatelet drugs as soon as intracranial bleeding is ruled out.
2.Consider carotid endarterectomy.
3.Lipid control.
4.Glucose control.
5.Smoking cessation.
6.Eliminate or reduce alcohol consumption.
7.Start an exercise plan for losing weight. Recommend starting with about 30 minutes of exercise three times per week.
D.Pharmaceutical therapy: The mainstay of treatment for TIA is pharmacologic management with antithrombotic agents:
1.Antiplatelet therapy:
a.Aspirin 50 to 325 mg/d. Aspirin should not be administered concomitantly with coumarin anticoagulants.
b.Dipyridamole (Persantine) 200 mg/d. May be given as an adjunct with warfarin therapy.
c.Aspirin + dipyridamole extended release (Aggrenox) 25/200 mg twice a day.
d.Clopidogrel (Plavix) 75 mg/d:
i.Aspirin is not routinely recommended with clopidogrel because of the risk of hemorrhage.
ii.No dosage adjustment is necessary with clopidogrel for elderly patients or patients with renal disease.
e.Ticlopidine (Ticlid) 250 mg twice a day is a second-line antiplatelet therapy for patients who cannot tolerate or do not respond to aspirin therapy. In some circumstances, it can be an alternative to clopidogrel.