Transient ischemic attack

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A transient ischemic attack (TIA) is a type of transient neurological attack. In a TIA, the focal area of brain cells were not killed, but only transiently deprived of blood supply and the signs of what seems to be a stroke, (or black-out), pass quickly and completely. A TIA is often a warning sign of an impending stroke, however, and like a true stroke, is a neurological emergency. None the less, a TIA is not a true stroke.

It may first be seen by an emergency physician, who will obtain neurological consultation.

Diagnosis

History and physical examination

The history and physical examination of patients with a possible TIA is difficult to interpret. Two neurologists interviewing the same patient have statistically 'substantial' but imperfect agreement about whether the patient had a TIA.[1] Disagreement may occur even when a 'standardized' patient is trained to give identical histories to each neurologist.[2]

Differential diagnosis

Other disorders that may cause similar symptoms are syncope, seizure, migraine, vestibulopathy, and conversion disorder.[3]

Treatment

Anti-platelet drugs

The most effective anti-platelet treatment is probably to combine aspirin, 25 mg twice a day with extended-release dipyridamole 200 mg twice a day according to the ESPRIT[4]

The combination of aspirin and clopidogrel should probably be avoided according to the MATCH[5] and CHARISMA[6] studies.

Invasive treatment

Carotid endarterectomy may prevent stroke in patients with more than 70% stenosis of the carotid artery.[7]

Expedited care protocol

A before and after comparison study found reduced mortality fell from 10% to 2% with the following protocol started the day the patient presents for medical care:[8]

  • "antiplatelet therapy: aspirin in patients not already on antiplatelet therapy (75 mg daily), or clopidogrel if aspirin was contraindicated" (loading dose of clopidogrel 300 mg).
    • * "In patients seen within 48 h of their event, or those seen within 7 days who were thought to be at particularly high early risk", clopidogrel (75 mg daily, to be stopped after 30 days; loading dose of clopidogrel 300 mg) was recommended in addition to aspirin."[9]
    • However, as noted above combining aspirin 25 mg twice a day with extended-release dipyridamole 200 mg twice a day might be a better choice than either aspirin alone or aspirin combined with clopidogrel.
  • simvastatin 40 mg daily
  • "blood pressure lowering unless systolic blood pressure was below 130 mm Hg on repeated measurement (either by increases in existing medication, or by commencement of perindopril 4 mg daily with or without indapamide 1·25 mg daily)"
  • anticoagulation as required
  • "Brain imaging was required before starting combination antiplatelet treatment or anticoagulation after a minor stroke"

Another approach is based on the ABCD2 score (see below). If score 6-7, hospitalize patient If score 4-5, image carotids and admit if significant stenosis.[10]

Prognosis

A meta-analysis of 18 cohort studies found the risk of stroke after 7 days varies from 0% to 13%. The lowest rates were in studies of emergency treatment by specialist stroke services.[11]

The risk of stroke among patients presenting to the emergency room with a TIA is approximately 3% to 5% in the next 2 days and 4% to 7% over the next week according to a second meta-analysis.[12] This meta-analysis thought the ABCD2 (below) provided the best estimate.

Prognosis is worse if the carotid artery has a greater than 70% obstruction.[13]

Calculating estimated prognosis

History and physical

"The simpler FAST scale could replace the more complex ROSIER for the initial assessment of patients with suspected acute stroke in the emergency department.". [14]

ABCD2

The ABCD2 score (http://www.stroke.org/site/DocServer/NSA_ABCD2_tool.pdf) is a clinical prediction rule that can predict likelihood of subsequent stroke over short term[15][16][17][18] or long term[19].

The risk of stroke depends on the study setting and how the data for the score was collected.[20] It may not work as well in a group with only a 2% risk of stroke within one week.[21]

Calculation of score

The score is calculated as:

  • Age ≥ 60 years = 1 point
  • Blood pressure at presentation ≥ 140/90 mm Hg = 1 point
  • Clinical features
unilateral weakness = 2 points
speech disturbance without weakness = 1 point
  • Duration of attack
≥ 60 minutes = 2 points
10-59 minutes = 1 point
  • Diabetes = 1 point

Interpretation of score, the risk for stroke from the original study:

  • Score 0-3 (low)
    • 2 day risk = 1.0%
    • 7 day risk = 1.2%
  • Score 4-5 (moderate)
    • 2 day risk = 4.1%
    • 7 day risk = 5.9%
  • Score 6–7 (high)
    • 2 day risk = 8.1%
    • 7 day risk = 11.7%
Improvements to the ABCD2

The ABCD2 score may be improved by adding the results of diffusion-weighted magnetic resonance imaging (MRI) to look for infarction.[22]

The score may be improved by the ABCD3 score which adds a point for 'dual' attacks within 7 days.[23]

The ABCD and ABCD2 may be improved by adding hyperglycemia and a history of hypertension.[24]

Diagnostic imaging

The rule may be improved by adding the presence of brain infarction visualized on diagnostic imaging using either brain infarction on either diffusion-weighted magnetic resonance imaging or computed tomography[25] or brain imaging combined with imaging of the carotid artery (ABCD3-I).[23]

References

  1. ↑ Kraaijeveld CL, van Gijn J, Schouten HJ, Staal A (1984). "Interobserver agreement for the diagnosis of transient ischemic attacks". Stroke 15 (4): 723–5. PMID 6464066. [e]
  2. ↑ Koudstaal PJ, Gerritsma JG, van Gijn J (1989). "Clinical disagreement on the diagnosis of transient ischemic attack: is the patient or the doctor to blame?". Stroke 20 (2): 300–1. PMID 2919420. [e]
  3. ↑ Johnston SC (2007). "Transient Neurological Attack: A Useful Concept?". JAMA 298 (24): 2912–2913. DOI:10.1001/jama.298.24.2912. PMID 18159062. Research Blogging.
  4. ↑ Halkes PH, van Gijn J, Kappelle LJ, Koudstaal PJ, Algra A (2006). "Aspirin plus dipyridamole versus aspirin alone after cerebral ischaemia of arterial origin (ESPRIT): randomised controlled trial". Lancet 367 (9523): 1665–73. DOI:10.1016/S0140-6736(06)68734-5. PMID 16714187. Research Blogging.
  5. ↑ Diener HC, Bogousslavsky J, Brass LM, et al (2004). "Aspirin and clopidogrel compared with clopidogrel alone after recent ischaemic stroke or transient ischaemic attack in high-risk patients (MATCH): randomised, double-blind, placebo-controlled trial". Lancet 364 (9431): 331–7. DOI:10.1016/S0140-6736(04)16721-4. PMID 15276392. Research Blogging.
  6. ↑ Bhatt DL, Fox KA, Hacke W, et al (2006). "Clopidogrel and aspirin versus aspirin alone for the prevention of atherothrombotic events". N. Engl. J. Med. 354 (16): 1706–17. DOI:10.1056/NEJMoa060989. PMID 16531616. Research Blogging.
  7. ↑ (1991) "Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. North American Symptomatic Carotid Endarterectomy Trial Collaborators". N. Engl. J. Med. 325 (7): 445–53. PMID 1852179. [e]
  8. ↑ Rothwell PM, Giles MF, Chandratheva A, et al (2007). "Effect of urgent treatment of transient ischaemic attack and minor stroke on early recurrent stroke (EXPRESS study): a prospective population-based sequential comparison". Lancet 370 (9596): 1432–42. DOI:10.1016/S0140-6736(07)61448-2. PMID 17928046. Research Blogging.
  9. ↑ Markus HS, Droste DW, Kaps M, et al (2005). "Dual antiplatelet therapy with clopidogrel and aspirin in symptomatic carotid stenosis evaluated using doppler embolic signal detection: the Clopidogrel and Aspirin for Reduction of Emboli in Symptomatic Carotid Stenosis (CARESS) trial". Circulation 111 (17): 2233–40. DOI:10.1161/01.CIR.0000163561.90680.1C. PMID 15851601. Research Blogging.
  10. ↑ Olivot JM, Wolford C, Castle J, Mlynash M, Schwartz NE, Lansberg MG et al. (2011). "TWO ACES: Transient Ischemic Attack Work-Up as Outpatient Assessment of Clinical Evaluation and Safety.". Stroke 42 (7): 1839-43. DOI:10.1161/STROKEAHA.110.608380. PMID 21617143. Research Blogging.
  11. ↑ Giles MF, Rothwell PM (2007). "Risk of stroke early after transient ischaemic attack: a systematic review and meta-analysis". Lancet Neurol 6 (12): 1063–72. DOI:10.1016/S1474-4422(07)70274-0. PMID 17993293. Research Blogging.
  12. ↑ Shah KH, Kleckner K, Edlow JA (2008). "Short-term prognosis of stroke among patients diagnosed in the emergency department with a transient ischemic attack". Ann Emerg Med 51 (3): 316-23. DOI:10.1016/j.annemergmed.2007.08.016. PMID 18282526. Research Blogging.
  13. ↑ Ois A, Cuadrado-Godia E, Rodríguez-Campello A, Jimenez-Conde J, Roquer J (2009). "High risk of early neurological recurrence in symptomatic carotid stenosis.". Stroke 40 (8): 2727-31. DOI:10.1161/STROKEAHA.109.548032. PMID 19498196. Research Blogging.
  14. ↑ Whiteley WN, Wardlaw JM, Dennis MS, Sandercock PA (2011). "Clinical scores for the identification of stroke and transient ischaemic attack in the emergency department: a cross-sectional study.". J Neurol Neurosurg Psychiatry 82 (9): 1006-10. DOI:10.1136/jnnp.2010.235010. PMID 21402744. Research Blogging.
  15. ↑ Asimos AW, Johnson AM, Rosamond WD, Price MF, Rose KM, Catellier D et al. (2010). "A multicenter evaluation of the ABCD2 score's accuracy for predicting early ischemic stroke in admitted patients with transient ischemic attack.". Ann Emerg Med 55 (2): 201-210.e5. DOI:10.1016/j.annemergmed.2009.05.002. PMID 19556026. Research Blogging.
  16. ↑ Johnston SC, Rothwell PM, Nguyen-Huynh MN, et al (2007). "Validation and refinement of scores to predict very early stroke risk after transient ischaemic attack". Lancet 369 (9558): 283-92. DOI:10.1016/S0140-6736(07)60150-0. PMID 17258668. Research Blogging.
  17. ↑ Rothwell PM, Giles MF, Flossmann E, et al (2005). "A simple score (ABCD) to identify individuals at high early risk of stroke after transient ischaemic attack". Lancet 366 (9479): 29-36. DOI:10.1016/S0140-6736(05)66702-5. PMID 15993230. Research Blogging.
  18. ↑ Chandratheva A, Mehta Z, Geraghty OC, Marquardt L, Rothwell PM (June 2009). "Population-based study of risk and predictors of stroke in the first few hours after a TIA". Neurology 72 (22): 1941–7. DOI:10.1212/WNL.0b013e3181a826ad. PMID 19487652. Research Blogging.
  19. ↑ Wijnhoud AD, Maasland L, Lingsma HF, Steyerberg EW, Koudstaal PJ, Dippel DW (2010). "Prediction of major vascular events in patients with transient ischemic attack or ischemic stroke: a comparison of 7 models.". Stroke 41 (10): 2178-85. DOI:10.1161/STROKEAHA.110.580985. PMID 20814011. Research Blogging.
  20. ↑ Giles MF, Rothwell PM (2010). "Systematic review and pooled analysis of published and unpublished validations of the ABCD and ABCD2 transient ischemic attack risk scores.". Stroke 41 (4): 667-73. DOI:10.1161/STROKEAHA.109.571174. PMID 20185786. Research Blogging.
  21. ↑ Perry JJ, Sharma M, Sivilotti ML, Sutherland J, Symington C, Worster A et al. (2011). "Prospective validation of the ABCD2 score for patients in the emergency department with transient ischemic attack.". CMAJ 183 (10): 1137-45. DOI:10.1503/cmaj.101668. PMID 21646462. PMC PMC3134721. Research Blogging.
  22. ↑ Giles MF, Albers GW, Amarenco P, Arsava EM, Asimos AW, Ay H et al. (2011). "Early stroke risk and ABCD2 score performance in tissue- vs time-defined TIA: A multicenter study.". Neurology 77 (13): 1222-8. DOI:10.1212/WNL.0b013e3182309f91. PMID 21865578. PMC PMC3179650. Research Blogging.
  23. ↑ 23.0 23.1 Merwick A, Albers GW, Amarenco P, Arsava EM, Ay H, Calvet D et al. (2010). "Addition of brain and carotid imaging to the ABCD² score to identify patients at early risk of stroke after transient ischaemic attack: a multicentre observational study.". Lancet Neurol 9 (11): 1060-9. DOI:10.1016/S1474-4422(10)70240-4. PMID 20934388. Research Blogging.
  24. ↑ Fothergill A, Christianson TJ, Brown RD, Rabinstein AA (2009). "Validation and refinement of the ABCD2 score: a population-based analysis.". Stroke 40 (8): 2669-73. DOI:10.1161/STROKEAHA.109.553446. PMID 19520983. Research Blogging.
  25. ↑ Giles MF, Albers GW, Amarenco P, Arsava MM, Asimos A, Ay H et al. (2010). "Addition of brain infarction to the ABCD2 Score (ABCD2I): a collaborative analysis of unpublished data on 4574 patients.". Stroke 41 (9): 1907-13. DOI:10.1161/STROKEAHA.110.578971. PMID 20634480. Research Blogging.
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