national-clinical-guidelines-for-stroke-fourth-edition

esources to respond to the need. Protocols should be in place for the use of the new oral
anticoagulants in the setting of TIA clinics, with processes to supervise the transition
from acute to longer-term anticoagulation.
4.3 Specialist diagnosis of acute transient event (TIA)
Following the recommendations above, all patients identified as having a potential
transient ischaemic event should be assessed and investigated at a specialist clinic either
within 24 hours or for low-risk patients, within a maximum of 1 week. This section
describes the further diagnostic process which has two goals: alternative diagnoses for the
transient neurological event must be ruled out as far as possible and the vascular territory
affected must be determined. Both are largely clinically driven processes depending upon
skilful history taking.
Evidence to recommendations
There is little evidence to guide the use of brain imaging after TIA. The consensus of the
working party is that imaging all patients referred to a neurovascular clinic is not a
clinically appropriate or cost-effective strategy given the high rate of TIA mimics in
most clinics. Imaging should be restricted to those patients where the results of such
imaging are likely to influence management such as confirming the territory of
ischaemia prior to making a decision about carotid artery surgery, and only once the
patient has been assessed clinically by a stroke specialist. Where imaging is considered
desirable, then the greater sensitivity of magnetic resonance imaging (MRI) to detect
ischaemic lesions, particularly using diffusion-weighted imaging, makes it the modality
of choice.
4.3.1 Recommendations
A People who have had a suspected TIA should be assessed by a specialist (within 1
week of symptom onset) before a decision on brain imaging is made.
B People who have had a suspected TIA who need brain imaging (that is, those in
whom vascular territory or pathology is uncertain) should undergo diffusionweighted
MRI except where contraindicated, in which case computed tomography
(CT) should be used.
C People who have a suspected TIA at high risk of stroke (eg an ABCD2 score of 4 or
above or with crescendo TIA) in whom vascular territory or pathology is uncertain,
should undergo urgent brain imaging (preferably diffusion-weighted MRI).
D People with a suspected TIA at low risk of stroke (eg an ABCD2 score of less than 4)
in whom vascular territory or pathology is uncertain should undergo brain imaging
within 1 week of onset of symptoms (preferably diffusion-weighted MRI).
4.3.2 Sources
A National Institute for Health and Clinical Excellence 2008b; Ay et al 2009
B–C National Institute for Health and Clinical Excellence 2008b
D National Institute for Health and Clinical Excellence 2008b; consensus
4 Acute phase care
© Royal College of Physicians 2012 41