TOC |  STAT | Neuro TIA - Transient Ischemic Attacks       RX                      See also  TIA 2002 (NEJM) |  Stroke 

Definitions
Transient ischemic attacks (TIAs) are focal neurologic deficits caused by retinal or cerebral vascular disease. They last less than 24 hours. Crescendo TIAs are defined as two TIAs within 24 hours, three within 3 days, or four within 2 weeks. Acute TIA is defined here as a TIA that occurs within 2 weeks of presentation to a physician.

Diagnostic Tests
There is no routine, standard laboratory evaluation of patients with TIA because the individual medical history and specific characteristics of the TIA influence the optimal sequence and extent of diagnostic testing.

1.  Duplex Ultrasound of the carotids may be helpful for those patients:

• whose symptoms are attributable to ischemia in a distribution of the anterior (carotid) circulation.
• who are candidates for endarterectomy of the carotids, where benefits of the surgery are likely to outweigh the burdens. If ordered, duplex ultrasound should be obtained within 3 days of presentation of an acute TIA (Grade C).

2.  Echocardiography should be considered for those patients whose TIA is thought to be cardiogenic. This study usually does not need to be performed on an emergency basis. If a cardiac origin of an embolus is suspected, the patient can be treated with heparin anticoagulation without an echocardiogram. The diagnostic yield of echocardiography in a patient over the age of 40 without cardiac murmur or evidence from the history/physical examination to suggest cardiac disease is so low as to make the test usually unnecessary.

When cardiac disease is strongly suspected and external 2-D echocardiography is not diagnostic, additional yield may be obtained by transesophageal echocardiography.

3.  CBC, Creat, ESR , glucose, PT/PTT, RPR/MAHTP, ECG - the studies could be obtained within 24 hours.

4.  Imaging Studies - Brain CT scan

5.Additional Tests / In selected cases the following additional tests may be appropriate:

• Anticardiolipin Antibody, Antithrombin III, Protein S, FBS, Lipid profile,
• Telemetry/Holter Monitor
• Selective, Digital, or Magnetic Resonance Angiography
• Magnetic Resonance Image of Brain

Initial Medical Management of TIA                       Top

1.Blood Pressure Control.
We encourage the use of antihypertensive agents that work by peripheral action, are short acting, and are unlikely to drop the blood pressure precipitouslly .

2.Anti-platelet agents
The antiplatelet agents aspirin and ticlopidine are both beneficial in the prevention of stroke following a TIA .

• Aspirin dose of 325 mg/day
• Ticlopidine (Ticlid) is 250 mg twice a day   (* may be associated with Thrombotic Thrombocytopenia Purpura)
  Patients who do not respond to or tolerate aspirin are candidates for ticlopidine . Patients offered ticlopidine must be willing to accept the supervision associated with the use of this agent.
• Plavix / Clopidogrel  75 mg/day  is safer than Ticlic (Ticlopidine)
• The combination of aspirin 25 mg and the antiplatelet agent dipyridamole  200 mg (Aggrenox)
  JAMA Jan. 5, 2000; 283 
  The FDA has approved a combination of aspirin and the antiplatelet agent dipyridamole (Aggrenox; Boehringer Ingelheim Pharmaceuticals Inc, Richfield, Conn) to reduce the risk of stroke for patients who have already had transient ischemic attacks or completed ischemic strokes due to blood clots in the brain. Each hard gelatin capsule contains 200 mg of dipyridamole in an extended-release form and 25 mg of aspirin as an immediate-release sugar-coated tablet.  
  The pivotal clinical trial of the drug was a double-blind, placebo-controlled, 24-month study that included 6602 patients who had an ischemic stroke (76%) or transient ischemic attack (24%) within 3 months before entering the trial. The study compared use of the combination pill with use of each active ingredient alone and with placebo.
  These comparisons showed that the combination reduced the risk of stroke by 36.8% compared with placebo, 22.1% compared with aspirin alone, and 24.4% compared with dipyridamole alone.
  The combination also reduced the risk of stroke or death by 24.2% compared with placebo, 12.1% compared with aspirin alone, and 10.3% compared with extended-release dipyridamole alone.  
  The most prevalent adverse reactions to the combination pill included headache (39.2%), dyspepsia (18.4%), abdominal pain (17.5%), nausea (16%), and diarrhea (12.7%). The incidence of gastrointestinal bleeding was 4.1% in the combination group, 2.2% in the dipyridamole group, 3.2% in the aspirin group, and 2.1% in the placebo group.

3. Treatment with heparin and warfarin is not routinely recommended for patients with TIA's
either acutely or as long-term therapy . Anticoagulation therapy is recommended for patients with TIA who have cardiac disease that is considered likely to cause embolism (atrial fibrillation, mitral stenosis, prosthetic cardiac valves, recent myocardial infarct, left ventricular thrombus, atrial myxoma, dilated cardiomyopathy, marantic (nonbacterial) endocarditis, but not for those with infective endocarditis without an underlying valvular defect . Anticoagulation therapy is an option in patients with TIA who continue to have symptoms despite antiplatelet therapy .

4.Intravenous heparinization of the patient with crescendo TIA is of undemonstrated benefit and without demonstrated harm. Management of the patient regarding this decision is suggested to be made on an individual basis .

5.Heparing and warfarin have been used to treat some cardiac conditions based on indirect evidence where the use of these medicines has not been shown to reduce TIA or stroke risk. These conditions include sick sinus syndrome, patent foramen ovale, atherosclerotic debris in thoracic aorta, spontaneous echocardiographic contrast, myocardial infarction longer than 2-6 months ago, hypokinetic or akinetic left ventricular segment, and calcification of the mitral annulus.

Longer-Term Medical Management                                  Top | Home Page

The following recommendations are appropriate to help reduce the risk of stroke for people who have had a TIA (Grade C recommendations):

1.After definitive evaluation and treatment of the TIA, and after a period of 24-48 hours, hypertension should be treated.

2. Anti-platelet Rx.: Aspirin 325 mg/day, Ticlopidine (Ticlid)  250 mg bid, or Clopidogrel (Plavix) 75 mg/day

2.Cigarette smoking should be discontinued.

3.Coronary artery disease, cardiac arrhythmias, congestive heart failure, and valvular heart disease should be treated appropriately. Anticoagulant and/or antiplatelet agents should be used for nonvalvular atrial fibrillation and post MI as described elsewhere in the Practice Guidlines.

4.Excessive alcohol use should be eliminated.

5.Oral contraceptives should be discontinued. If it is not possible to discontinue them, a low-estrogen agent may be used.

6.Hyperlipidemia should be treated as recommended for reduction of coronary artery disease.

7.Physical activity as tolerated should be encouraged.

8.Discontinuation of estrogen replacement therapy for women who are postmenopausal is not recommended.

Surgical Management

Extracranial Carotid Artery Disease

Stenosis >70%, Single or multiple TIAs, irrespective of response to antiplatelet drugs in the presence of high-grade stenosis ipsilateral to the site of brain ischemia in a good candidate for surgery, are indications for carotid endarterectomy (Grade A recommendation).

Stenosis < 70%

Controversy continues with the currently limited available data. Discussion with consultants from the Department of Neurology or Department of Vascular Surgery may be helpful.

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