Transient Ischaemic Attacks: How to diagnose and what to do?
Transient ischaemic attack (TIA) is a sudden focal neurological deficit that lasts less than 24 hours. It requires acute assessment and if the symptoms and signs have not fully resolved at the time of consultation, the patient should be treated as if they are having a stroke. Patients with TIA have a 5.2% risk of having a stroke in the first week after TIA and require urgent assessment and modification of risk factors. ‘Time is key’ said Professor Richard McManus (Birmingham, UK). The ABCD2 score can be used to decide how rapidly patients need to be seen in a specialist clinic.
A score or four or more means the patient should be seen as soon as possible, and at least within 24 hours, by a stroke specialist. Those with a score of less than four should be seen within one week. However there is evidence that many patients with symptoms of TIA may wait to see their GP rather than accessing emergency medical care which can introduce a delay in treatment. Professor McManus reviewed the evidence for secondary prevention in patients with a history of TIA or stroke. The European Stroke Prevention Study 2 showed a reduced rate of recurrent stroke over two years in those receiving a combination of aspirin and dipyridamole. The PROGRESS trial showed a beneficial effect of perindopril and hydrochlorothiazide in reducing blood pressure and risk of recurrent stroke and overall cardiovascular mortality in patients with previous TIA or stroke. Anticoagulation in patients with atrial fibrillation over the age of 75 was supported by the findings of the BAFTA study which showed a reduced stroke risk with no increase in major adverse effects compared to aspirin. Carotid endarterectomy is also beneficial in patients with more than 70% stenosis and should be carried out within two weeks of TIA. ‘Time really is the key’, Prof McManus emphasised.