Transient ischemic attack: Difference between revisions

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===Calculating estimated prognosis===
===Calculating estimated prognosis===
The ABCD<sup>2</sup> score is a [[clinical prediction rule]] that can predict likelihood of subsequent [[stroke]].<ref name="pmid17258668">{{cite journal |author=Johnston SC, Rothwell PM, Nguyen-Huynh MN, ''et al'' |title=Validation and refinement of scores to predict very early stroke risk after transient ischaemic attack |journal=Lancet |volume=369 |issue=9558 |pages=283-92 |year=2007 |pmid=17258668 |doi=10.1016/S0140-6736(07)60150-0}}</ref><ref name="pmid15993230">{{cite journal |author=Rothwell PM, Giles MF, Flossmann E, ''et al'' |title=A simple score (ABCD) to identify individuals at high early risk of stroke after transient ischaemic attack |journal=Lancet |volume=366 |issue=9479 |pages=29-36 |year=2005 |pmid=15993230 |doi=10.1016/S0140-6736(05)66702-5}}</ref><ref name="pmid19487652">{{cite journal |author=Chandratheva A, Mehta Z, Geraghty OC, Marquardt L, Rothwell PM |title=Population-based study of risk and predictors of stroke in the first few hours after a TIA |journal=Neurology |volume=72 |issue=22 |pages=1941–7 |year=2009 |month=June |pmid=19487652 |doi=10.1212/WNL.0b013e3181a826ad |url= |issn=}}</ref>
The ABCD<sup>2</sup> score is a [[clinical prediction rule]] that can predict likelihood of subsequent [[stroke]].<ref name="pmid19556026">{{cite journal| author=Asimos AW, Johnson AM, Rosamond WD, Price MF, Rose KM, Catellier D et al.| title=A multicenter evaluation of the ABCD2 score's accuracy for predicting early ischemic stroke in admitted patients with transient ischemic attack. | journal=Ann Emerg Med | year= 2010 | volume= 55 | issue= 2 | pages= 201-210.e5 | pmid=19556026
| url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=clinical.uthscsa.edu/cite&retmode=ref&cmd=prlinks&id=19556026 | doi=10.1016/j.annemergmed.2009.05.002 }} </ref><ref name="pmid17258668">{{cite journal |author=Johnston SC, Rothwell PM, Nguyen-Huynh MN, ''et al'' |title=Validation and refinement of scores to predict very early stroke risk after transient ischaemic attack |journal=Lancet |volume=369 |issue=9558 |pages=283-92 |year=2007 |pmid=17258668 |doi=10.1016/S0140-6736(07)60150-0}}</ref><ref name="pmid15993230">{{cite journal |author=Rothwell PM, Giles MF, Flossmann E, ''et al'' |title=A simple score (ABCD) to identify individuals at high early risk of stroke after transient ischaemic attack |journal=Lancet |volume=366 |issue=9479 |pages=29-36 |year=2005 |pmid=15993230 |doi=10.1016/S0140-6736(05)66702-5}}</ref><ref name="pmid19487652">{{cite journal |author=Chandratheva A, Mehta Z, Geraghty OC, Marquardt L, Rothwell PM |title=Population-based study of risk and predictors of stroke in the first few hours after a TIA |journal=Neurology |volume=72 |issue=22 |pages=1941–7 |year=2009 |month=June |pmid=19487652 |doi=10.1212/WNL.0b013e3181a826ad |url= |issn=}}</ref>


The score is calculated as:
The score is calculated as:

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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.

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"

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.[10]

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.[11] This meta-analysis thought the ABCD2 (below) provided the best estimate.

Prognosis is worse if the carotid artery has a greater than 70% obstruction.[12]

Calculating estimated prognosis

The ABCD2 score is a clinical prediction rule that can predict likelihood of subsequent stroke.[13][14][15][16]

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:

  • 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%

The ABCD and ABCD2 may be improved by adding hyperglycemia and a history of hypertension.[17]

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. 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.
  11. 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.
  12. 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.
  13. 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.
  14. 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.
  15. 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.
  16. 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.
  17. 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.