Transient ischaemic attack
From Ganfyd
Transient Ischaemic Attack (TIA), a temporary blockage of an artery towards or in the brain, leading to temporary neurological deficit that resolves by definition within 24 hours. It is a major risk factor for stroke and such patients should be regarded as medical emergencies.
 | In UK practice urgent within one week and preferably one working day, full assessment of TIAs will increasingly be expected after publication of the EXPRESS study[1] which showed an 80% improvement in outcome compared to normal practice. |
Contents |
Technical qualification
The above clinical definition needs to be seen in the context that modern MRI techniques, particularly early diffusion cerebral MR imaging show that TIAs that do not reverse within one hour have at least a 50% chance of actually being associated with ischaemic stroke[2].
Clinical assessment
This needs to be based on adequate history taking and a good understanding of neurology. There is a poor correlation between the diagnosis of TIA made by many front line health professionals and the actual diagnosis, although that made by experienced stroke physicians is much more accurate. | While the overwhelming majority of TIAs are thromboembolic, any other embolism such as air embolism, the bends, fat embolisation or trauma causing say kinking of a vessel could be responsible. Patients who get TIAs while having an iv infusion should be assumed to have a shunt allowing direct air entry into the systemic circulation until proved otherwise |
Investigations
- Neurological examination
- MR imaging (Diffusion MRI in first 48 hours of all patients who stage full recovery is the investigation of choice, and should be done where resources allow)
- Computed tomography
- Carotid doppler
- Electrocardiogram
- 24 hour ECG
- Echocardiogram
- Serum cholesterol levels
Prognosis
In patients presenting with ischaemic stroke with a warning TIA, these occur in 17% on the day of the TIA, 9% on the next day, and 43% within in next 6 days[3]. Historic sources completely underestimated this risk of stroke claiming-1% to 2% at 7 days and 2% to 4% at 1 month[4] leading to interventional nihilism for many years, both in the general population and their advising health care professionals. The actual risks of first ever TIA are over 8% of stroke at 7 days[5] and at one year the risk of stroke, myocardial infarction, or death is 22% (95% CI 20.0 to 23.6)[6].
Prognostic Scores
Clinicians are recommended to stratify patients management using one of three validated scores:
In UK practice it appears safe to use the ABCD or ABCD2 scores to determine who needs immediate hospital admission and who needs urgent stroke/TIA clinic referral.
Treatment
Immediate treatment
In thromboembolic TIA here is now considerable evidence for the benefit of early institution of proven long term therapies and in selected patients rapid assessment and early intervention if indicated such as carotid endarterectomy. You should have a local guideline which needs regular updating as there have been many recent advances, but some may not be accessible due to resource and differential evidence interpretation constraints.
Long term treatment
- Aspirin at low dose
- Statins
- Smoking cessation
- Warfarin in atrial fibrillation
Links
This article is a work in progress. Please feel free to contribute to it.
References
- ↑ Rothwell PM, Giles MF, Chandratheva A, Marquardt L, Geraghty O, Redgrave JN, Lovelock CE, Binney LE, Bull LM, Cuthbertson FC, Welch SJ, Bosch S, Carasco-Alexander F, Silver LE, Gutnikov SA, Mehta Z. Effect of urgent treatment of transient ischaemic attack and minor stroke on early recurrent stroke (EXPRESS study): a prospective population-based sequential comparison. Lancet. 2007 Oct 20; 370(9596):1432-42.(Link to article – subscription may be required.)
- ↑ Lamy C, Oppenheim C, Calvet D, Domigo V, Naggara O, Méder JL, Mas JL. Diffusion-weighted MR imaging in transient ischaemic attacks. European radiology. 2006 May; 16(5):1090-5.(Link to article – subscription may be required.)
- ↑ Sylaja PN, Coutts SB, Subramaniam S, Hill MD, Eliasziw M, Demchuk AM. Acute ischemic lesions of varying ages predict risk of ischemic events in stroke/TIA patients. Neurology. 2007 Feb 6; 68(6):415-9.(Link to article – subscription may be required.)
- ↑ Lovett JK, Dennis MS, Sandercock PA, Bamford J, Warlow CP, Rothwell PM. Very early risk of stroke after a first transient ischemic attack. Stroke; a journal of cerebral circulation. 2003 Aug; 34(8):e138-40.(Link to article – subscription may be required.)
- ↑ Lovett JK, Dennis MS, Sandercock PA, Bamford J, Warlow CP, Rothwell PM. Very early risk of stroke after a first transient ischemic attack. Stroke; a journal of cerebral circulation. 2003 Aug; 34(8):e138-40.(Link to article – subscription may be required.)
- ↑ Hill MD, Yiannakoulias N, Jeerakathil T, Tu JV, Svenson LW, Schopflocher DP. The high risk of stroke immediately after transient ischemic attack: a population-based study. Neurology. 2004 Jun 8; 62(11):2015-20.
