Transient Ischemic Attack

Educational Objectives

The goal of this program is to improve the diagnosis and management of stroke. After hearing and assimilating this program, the clinician will be better able to:

1. Prevent stroke by intervening in cases of transient ischemic attack (TIA).

2. Differentiate between TIA and other diagnoses with similar signs and symptoms.

Summary

Background: TIAs indicative of instability that may lead to stroke; present opportunity for prevention; educating patients on importance of TIA management may help to prevent some of 800,000 strokes per year in United States

Definition: originally defined in 1970s as focal cerebral dysfunction of vascular origin with rapid onset and duration of ≤24 hr; clears completely without residual deficit; allowed some overlap between small strokes and TIA; definition updated in 2009 to transient neurologic dysfunction caused by ischemia without acute infarction; timing no longer defined; not considered TIA if infarction seen on imaging

Symptoms: may include weakness in face, arm, leg, or combination; trouble speaking due to aphasia and/or dysarthria; visual field deficit or loss of vision in one eye; loss of sensation on one side of body; usually lasts <1 hr; not consistent with TIA — nonfocal symptoms (eg, lightheadedness, dizziness); positional vertigo focal sign, but usually not due to ischemia; isolated syncope usually hemodynamic or cardiovascular; diffusely blurred vision, forgetfulness, and transient amnesia usually not cerebrovascular

Case example: 51-yr-old woman suddenly developed left-sided weakness and slurred speech (suggesting right-hemispheric stroke); history of hypertension, coronary artery disease, and smoking; takes daily aspirin; no contraindications to intravenous (IV) tissue plasminogen activator (tPA) therapy; blood pressure 164/103 mm Hg; pulse 80; patient alert and lucid, with left facial droop and left hemiparesis; CT of head normal; no significant abnormalities noted on laboratory studies; patient treated with IV tPA 2 hr and 45 min after onset of symptoms; completely recovered within 16 hr; MRI showed no visible ischemia; might be considered TIA, but more likely that tPA averted stroke

Studies: Kidwell study — stroke lesions seen on MRI in ≈48% of patients diagnosed with TIA; likelihood of finding lesion on MRI increases with longer duration of symptoms; Cincinnati study — risk for stroke increases rapidly during first few days after TIA, then decreases to baseline risk by 3 mo; intervention most effective in first 1 to 2 wk after TIA when stroke risk highest (analogous to unstable angina and risk for MI)

Differential diagnosis: migraine — complex visual distortions (eg, curved images, colorful visual patterns) typical of migraine; likelihood of associated migraine headache may decrease with age; late-life (age 60–70 yr) migraine accompaniments may more closely resemble TIA; patients presenting after multiple spells less likely to be experiencing TIA; thromboembolic events more likely to cause loss of vision than complex visual phenomena; migraine aura lasts ≈20 min; seizures — can mimic TIA; may cause altered consciousness; history of multiple previous spells decreases likelihood of TIA diagnosis; electroencephalography (EEG) may show focal discharge indicating seizure; MRI may show lesion that triggers seizure; cerebral hypoperfusion syndromes — associated with focal deficits as well as diffuse symptoms (eg, dizziness, lightheadedness); unstable blood pressure or arrhythmia and symptoms provoked by positional change suggest this diagnosis; recurrent spells without serious consequences rule out TIA; metabolic derangements — usually produce diffuse cerebral symptoms, but patients may have focal symptoms; diagnosed by blood testing; history of multiple spells reassuring; radiculopathy — symptoms in one extremity may mimic stroke; frequently painful; symptoms may follow nerve root distribution; symptoms primarily sensory (if cervical radiculopathy) and possibly positional; duration varies; multiple episodes reassuring; psychogenic disorders — often stress related; complaints of pain unlikely with TIA; reported symptoms may only be possible with 2 separate lesions; history and examination often inconsistent; patient may have psychiatric history

Stroke prediction: studies — 1) patients in California with diagnosis of TIA in emergency department followed for 90 days; 2) patients in United Kingdom diagnosed with TIA by neurologist followed for 30 days; age >60 yr, blood pressure >140/90 mm Hg, hemiparesis, altered speech, duration >10 min, and presence of diabetes found to be independent factors predicting stroke; ABCD2 score for TIAs developed on basis of these results using point assignments for each factor; 7-day and 30-day risks for stroke increase with score; score ≥4 indicates higher risk (urgent evaluation indicated)

Evaluation of TIA: CT, CTA, MRI, or MRA of brain; obtain arterial images if MRI used, or separate CTA; ultrasonography to image carotids; CTA or MRA confirmation if significant disease found (2 confirmatory noninvasive tests usually preclude need for catheter angiography); blood testing includes complete blood count, glucose level, and electrolytes; ECG monitoring indicated if significant cardiac arrhythmias such as AF suspected; blood pressure monitoring; TTE, followed by TEE if cardioembolic stroke suspected

Treatment of TIA: similar to treatment of stroke; treatment of hypertension has greatest impact on preventing subsequent vascular events; antiplatelet treatment reduces stroke risk; anticoagulation, when indicated; carotid endarterectomy in selected patients; less common therapies — drug rehabilitation; treatment of hypercoagulable disorders; use of corticosteroids or immunosuppression for inflammatory vasculitis

 

Readings

Amerenco P et al: Atherosclerotic disease of the aortic arch and the risk of ischemic stroke. N Eng J Med 331:1474, 2004; Claver E et al: Giant thrombus trapped in patent foramen ovale with pulmonary embolus and stroke. J Am Soc Echocardiogr 17:916, 2004; Easton JD et al: Definition and evaluation of transient ischemic attack: a scientific statement for healthcare professionals from the American Heart Association/American Stroke Association Stroke Council; Council on Cardiovascular Surgery and Anesthesia; Council on Cardiovascular Radiology and Intervention; Council on Cardiovascular Nursing; and the Interdisciplinary Council on Peripheral Vascular Disease. The American Academy of Neurology affirms the value of this statement as an educational tool for neurologists. Stroke 40: 2276, 2009; Fisher CM: Late-life migraine accompaniments — further experience. Stroke 17:1033, 1986; Furlan AJ et al: Closure or medical therapy for cryptogenic stroke with patent foramen ovale. N Eng J Med 366:991, 2012; Guillon B et al: Long-term follow-up of aneurysms developed during extracranial internal carotid artery dissection. Neurology 53:117, 1999; Hagen PT et al: Incidence and size of patent foramen ovale during the first 10 decades of life: an autopsy study of 965 normal hearts. Mayo Clin Proc 59:17, 1984; Homma S et al: Effect of medical treatment in stroke patients with patent foramen ovale: patent foramen ovale in Cryptogenic Stroke Study. Circulation 105:2625, 2002; Johnston SC et al: Short-term prognosis after emergency department diagnosis of TIA. JAMA 284:2901, 2000; Johnston SC et al: Validation and refinement of scores to predict very early stroke risk after transient ischaemic attack. Lancet 369:283, 2007 Kidwell CS et al: Diffusion MRI in patients with transient ischemic attacks. Stroke 30:1174, 2009; Kleindorfer D et al: Incidence and short-term prognosis of transient ischemic attack in a population-based study. Stroke 36:720, 2005; Mas JL et al: Recurrent cerebrovascular events associated with patent foramen ovale, atrial septal aneurysm, or both. N Eng J Med 345:1740, 2001; Meissner I et al: Prevalence of potential risk factors for stroke assessed by transesophageal echocardiography and carotid ultrasonography: the SPARC study. Stroke Prevention: Assessment of Risk in a Community. Mayo Clin Proc 74:862, 1999; Meissner I et al: Patent foramen ovale: innocent or guilty? Evidence from a prospective population-based study. J Am Coll Cardiol 47:447, 2006; Rothwell PM et al: A simple score (ABCD) to identify individuals at high early risk of stroke after transient ischaemic attack. Lancet 366:29, 2005; Schwertz H et al: Transesophageal echocardiographic image of a thrombus crossing a persistent foramen ovale from the right into the left atrium. J Am Soc Echocardiogr 18:278, 2005.

Disclosures

In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the planning committee to disclose relevant financial relationships within the past 12 months that might create any personal conflicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary business or commercial interest. For this program, the faculty and planning committee reported nothing to disclose.

Acknowledgements

Dr. Bruno were recorded at Comprehensive Stoke Management Update 2012, held April 5–7, 2012, on Hilton Head Island, SC, and sponsored by Georgia Health Sciences University and the Division of Continuing Medical Education at Medical College of Georgia. For information about upcoming about upcoming CME events from the Medical College of Georgia at GHSU, please visit georgiahealth.edu/ce/medicalce. The Audio-Digest Foundation thanks the speaker and the sponsors for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0 CE contact hours.

Lecture ID:

NE031402

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.

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