The acute diagnosis of TIA is based on clinical history. Witness accounts are useful, but may not be available.
If a patient still has neurological symptoms when they are seen in the ED, it is more probable that they have had a stroke.
Important points to establish from the history are:
- The time of symptom onset and the duration of symptoms
- Associated symptoms
- Past medical history of co-morbidities associated with increased risk for TIA and CVA
- Past medical history of possible causes of neurological deficit other than TIA e.g. malignancy
In order to differentiate from stroke mimics, it is important to ascertain the following:
- The symptoms are acute in onset
- Symptoms reach maximum intensity within seconds
- Symptoms all begin at the same time
- There may be single or multiple episodes
Learning bite
A typical TIA will present with risk factors for vascular disease and one of the following:
- Limb weakness as a presenting symptom
- Speech difficulty as a presenting symptom
- Transient monocular loss of vision
- The symptoms are focal
- The symptoms fit with a vascular territory of the brain.
- The symptoms are negative
- Loss of function, as opposed to conditions such as migraine, which produce positive symptoms, for example flashing lights or wavy lines.
TIA symptoms are characterised by a loss of function.