Transient ischemic attack
Overview (summary)
A Transient Ischemic Attack (TIA) is a brief loss of neurologic function. In a TIA, the affected 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 neurologic emergency. None the less, a TIA is not a true stroke.
Treatment
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:[1]
- "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)
- 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
- "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."[2]
- Brain imaging was required before starting combination antiplatelet treatment or anticoagulation after a minor stroke.
Prognosis
Patients diagnosed with a TIA are sometimes said to have had a warning for an approaching cerebrovascular accident. If the time period of blood supply impairment lasts more than a few minutes, the nerve cells of that area of the brain die and cause permanent neurologic deficit. One third of the people with TIA later have recurrent TIAs and one third have a stroke due to permanent nerve cell loss.
The ABCD2 score can predict likelihood of subsequent stroke.[3][4]
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%
References
- ↑ 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.
- ↑ 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.
- ↑ 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.
- ↑ 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.