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CME

Transient Ischemic Attack (TIA)

General Information

Description

  • TIA is a transient episode of neurologic dysfunction caused by focal ischemia of the brain, spinal cord, or retina, and without detection of acute infarction on neuroimaging.1

Also called

  • acute neurovascular syndrome

Definitions

  • TIA
    • American Heart Association/American Stroke Association 2009 tissue-based definition of TIA - transient episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia, without acute infarction (Stroke 2009 Jun;40(6):2276)
    • previous time-based definition was reversible focal ischemic neurologic dysfunction lasting < 24 hours1
      • generally accepted for use in absence of computed tomography or magnetic resonance imaging availability
      • 30% of patients diagnosed with TIA using this definition may in fact have infarcted brain
  • ischemic stroke - episode of neurological dysfunction caused by focal cerebral, spinal, or retinal infarction (Stroke 2013 Jul;44(7):2064)
  • nondisabling stroke - transient neurologic symptoms with presence of brain infarction but mild (National Institutes of Health Score ≤ 3 points) or no persistent clinical deficits1

Types

Amaurosis fugax

  • amaurosis fugax
    • transient monocular blindness lasting seconds to minutes
    • caused by ischemia to retina, choroid, or optic nerve
    • considered a subform of TIA
    • common mechanism is embolism from the ipsilateral carotid nerve; another possible cause is giant cell arteritis
    • less commonly reported causes include
    • history and physical for amaurosis fugax
      • ask about history of transient monocular blindness
      • perform retinal exam for retinal emboli
      • perform neurological exam to rule out focal neurological features
    • diagnostic testing for amaurosis fugax
      • perform lab testing for erythrocyte sedimentation rate and c-reactive protein levels for giant cell arteritis
      • perform ultrasound of carotid arteries to detect possible carotid stenosis
      • consider neuroimaging, as patients may have asymptomatic infarctions
    • management of amaurosis fugax dependent on underlying cause
    • PubMed26278894Cerebrovascular diseases (Basel, Switzerland)Cerebrovasc Dis20150101403-4151-6151Reference - Clin Ophthalmol 2016;10:2165full-text, Cerebrovasc Dis 2015;40(3-4):151
    • Study Summary
      18.9% reported prevalence of ≥ 70% carotid stenosis in adults with amaurosis fugax
      Details
      studySummary
      • Cohort Studybased on retrospective cohort study
      • 302 adults (mean age 66 years, 54% women) with amaurosis fugax were assessed by ultrasound for carotid artery stenosis at Sahlgrenska University Hospital in Gothenburg from 2004 to 2010
      • 18.9% of adults had significant carotid stenosis (≥ 70% stenosis); 14.2% of adults underwent carotid endarterectomy
      • 1.7% of adults displayed retinal artery emboli on examination
      • factors associated with increased risk of ≥ 70% carotid stenosis
        • male sex (adjusted odds ratio [OR] 2.62, 95% CI 1.26-5.46)
        • current smoking (adjusted OR 6.26, 95% CI 2.62-14.93)
        • diabetes (adjusted OR 3.68, 95% CI 1.37-9.9)
        • prior vasculitis (adjusted OR 10.78, 95% CI 1.36-85.5)
      • PubMed27826182Clinical ophthalmology (Auckland, N.Z.)Clin Ophthalmol20161031102165-21702165Reference - Clin Ophthalmol 2016;10:2165full-text

References

General References Used

  1. Duca A, Jagoda A. Transient Ischemic Attacks: Advances in Diagnosis and Management in the Emergency Department. Emerg Med Clin North Am. 2016 Nov;34(4):811-835
  2. Coutts SB. Diagnosis and Management of Transient Ischemic Attack. Continuum (Minneap Minn). 2017 Feb;23(1, Cerebrovascular Disease):82-92
  3. Easton JD, Saver JL, Albers GW, 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. 2009 Jun;40(6):2276-93
  4. Casaubon LK, Boulanger JM, Blacquiere D, et al; Heart and Stroke Foundation of Canada Canadian Stroke Best Practices Advisory Committee. Canadian Stroke Best Practice Recommendations (CSBPR): Hyperacute stroke care guidelines, update 2015. Int J Stroke 2015 Aug;10(6):924-40

Recommendation Grading Systems Used

  • American Heart Association/American Stroke Association (AHA/ASA) grading system for recommendations
    • classifications of recommendations
      • Class I - procedure or treatment should be performed or administered
      • Class IIa - reasonable to perform procedure or administer treatment, but additional studies with focused objectives needed
      • Class IIb - procedure or treatment may be considered; additional studies with broad objectives needed, additional registry data would be useful
      • Class III - procedure or treatment should not be performed or administered because it is not helpful or may be harmful
        • Class III ratings may be subclassified as Class III No Benefit or Class III Harm
    • levels of evidence
      • Level A - data derived from multiple randomized clinical trials or meta-analyses
      • Level B - data derived from single randomized trial or nonrandomized studies
      • Level C - only expert opinion, case studies, or standard of care
  • American College of Cardiology/American Heart Association (ACC/AHA) grading system for recommendations
    • classifications of recommendations
      • Class I - procedure or treatment should be performed or administered
      • Class IIa - reasonable to perform procedure or administer treatment, but additional studies with focused objectives needed
      • Class IIb - procedure or treatment may be considered; additional studies with broad objectives needed, additional registry data would be useful
      • Class III - procedure or treatment should not be performed or administered because it is not helpful or may be harmful
        • Class III ratings may be subclassified as Class III No Benefit or Class III Harm
    • levels of evidence
      • Level A - high-quality evidence from > 1 randomized controlled trial or meta-analysis of high-quality randomized controlled trials
      • Level B-R - moderate-quality evidence from ≥ 1 randomized controlled trial or meta-analysis of moderate-quality randomized controlled trials
      • Level B-NR - moderate-quality evidence from ≥ 1 well-designed nonrandomized trial, observational studies, or registry studies, or meta-analysis of such studies
      • Level C-LD - randomized or nonrandomized studies with methodological limitations or meta-analyses of such studies
      • Level C-EO - consensus of expert opinion based on clinical experience
    • Reference - ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline on prevention, detection, evaluation, and management of high blood pressure in adults (29133356Hypertension 2018 Jun;71(6):e13)
  • American College of Chest Physicians (ACCP) uses Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach to recommendations
    • recommendations
      • Strong - benefits outweigh risk and burdens, or vice versa; recommend
      • Weak - conditional, benefits closely balanced with risks and burden; suggest
      • Ungraded - consensus based, uncertainty due to lack of evidence, expert opinion that benefits outweigh risk and burdens, or vice versa; insufficient evidence for a graded recommendation
    • quality of evidence
      • High - confidence that true effect lies close to estimate of effect from the estimate of effect
      • Moderate - moderate confidence in effect estimate, true effect likely to be close to the estimate of the effect, but possibility it is substantially different
      • Low - confidence in the effect estimate is limited, true effect may be substantially different from estimate of effect
      • Very low - little confidence in the effect estimate. true effect is likely to be substantially different
    • Reference - ACCP Evidence-Based Clinical Practice Guidelines for Antithrombotic Therapy and Prevention of Thrombosis (Ninth Edition) guideline and expert panel report on antithrombotic therapy for atrial fibrillation (Chest 2018 Nov;154(5):1121)
  • American College of Chest Physicians (ACCP) grades
    • Grade 1 - strong recommendation based on clear risk/benefit balance
    • Grade 2 - weak recommendation based on unclear or close risk/benefit balance
    • Grade A - high-quality evidence based on consistent evidence from randomized trials without important limitations or exceptionally strong evidence from observational studies
    • Grade B - moderate-quality evidence based on randomized trials with important limitations (inconsistent results, methodologic flaws, indirect or imprecise results) or very strong evidence from observational studies
    • Grade C - low- or very low-quality evidence based on evidence for ≥ 1 critical outcome from observational studies, case series, or randomized trials with serious flaws or indirect evidence
    • Reference - ACCP evidence-based clinical practice guideline on methodology for development of antithrombotic therapy and prevention of thrombosis (22315256Chest 2012 Feb;141(2 Suppl):53Sfull-text), commentary can be found in 23546508Chest 2013 Apr;143(4):1190
  • Canadian Cardiovascular Society (CCS) grading system for recommendations
    • strength of recommendation
      • Strong
      • Conditional (weak)
    • quality of evidence
      • High - future research unlikely to change confidence in estimate of effect; multiple well-designed, well-conducted clinical trials
      • Moderate - further research likely to have important impact on confidence in estimate of effect and may change estimate; limited clinical trials, inconsistency of results, or study limitations
      • Low - further research very likely to have significant impact on estimate of effect and is likely to change estimate; small number of clinical studies or cohort observations
      • Very Low - estimate of effect is very uncertain; case studies or consensus opinion
    • References
  • Canadian Stroke Best Practice Recommendations (CSBPR) levels of evidence
    • Evidence Level A
      • meta-analysis of randomized controlled trials or consistent findings from ≥ 2 randomized trials
      • desirable effects clearly outweigh undesirable effects or vice versa
    • Evidence Level B
      • single randomized controlled trial or consistent findings from ≥ 2 well-designed nonrandomized and/or uncontrolled trials, and large observational studies
      • desirable effects outweigh or are closely balanced with undesirable effects or vice versa
    • Evidence Level C
      • writing group consensus and/or supported by limited research evidence
      • desirable effects outweigh or are closely balanced with undesirable effects or vice versa
    • Reference - CSBPR Overview and Methodology (CSBPR 2014 PDF)
  • European Society of Cardiology (ESC) grading system for recommendations
    • classes of recommendations
      • Class I - evidence and/or general agreement that given treatment or procedure is beneficial, useful, and effective
      • Class II - conflicting evidence and/or divergence of opinion about usefulness/efficacy of given treatment or procedure
        • Class IIa - weight of evidence/opinion in favor of usefulness/efficacy
        • Class IIb - usefulness/efficacy less well-established by evidence/opinion
      • Class III - evidence or general agreement that given treatment or procedure is not useful/effective, and in some cases may be harmful
    • levels of evidence
      • Level A - data derived from multiple randomized clinical trials or meta-analyses
      • Level B - data derived from single randomized trial or large nonrandomized studies
      • Level C - consensus of opinion of experts and/or small studies, retrospective studies, registries
    • References

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How to cite

National Library of Medicine, or "Vancouver style" (International Committee of Medical Journal Editors):

  • DynaMed [Internet]. Ipswich (MA): EBSCO Information Services. 1995 - . Record No. T116640, Transient Ischemic Attack (TIA); [updated 2018 Nov 30, cited place cited date here]. Available from https://www.dynamed.com/topics/dmp~AN~T116640. Registration and login required.

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