Investigations

These are designed to ascertain the cause of the transient ischaemic attack and to assess risk factors for vascular disease.

Investigations include:

• Blood tests:
  • FBC
  • ESR or CRP
  • platelets
  • urea
  • blood glucose
  • syphilis serology
• chest X-ray
• ECG and 24 hour tape to look for paroxysmal arrhythmia
• transesophageal & transthoracic echocardiography (2)
• carotid duplex scanning " carotid angiography (3)
• CT scan - to recognize subarachnoid haemorrhages, intracranial haemorrhages, or subdural hematoma, to differentiate haemorrhages from tumors and other masses (2)

With respect to brain imaging and carotid imaging NICE suggest (1):

• do not offer CT brain scanning to people with a suspected TIA unless there is clinical suspicion of an alternative diagnosis that CT could detect
• after specialist assessment in the TIA clinic, consider MRI (including diffusionweighted and blood-sensitive sequences) to determine the territory of ischaemia, or to detect haemorrhage or alternative pathologies. If MRI is done, perform it on the same day as the assessment
• carotid imaging
  • everyone with TIA who after specialist assessment is considered as a candidate for carotid endarterectomy should have urgent carotid imaging

Notes:

• examples where brain imaging is helpful in the management of TIA are:
  • people being considered for carotid endarterectomy where it is uncertain whether the stroke is in the anterior or posterior circulation
  • people with TIA where haemorrhage needs to be excluded, for example long duration of symptoms or people on anticoagulants
  • where an alternative diagnosis (for example migraine, epilepsy or tumour) is being considered
• type of brain imaging for people with suspected TIA
  • people who have had a suspected TIA who need brain imaging (that is, those in whom vascular territory or pathology is uncertain) should undergo diffusion-weighted MRI except where contraindicated, in which case CT (computed tomography) scanning should be used

Reference:

• (1) NICE (May 2019). The diagnosis and acute management of stroke and transient ischaemic attacks
• (2) Nina J Solenski. Transient Ischemic Attacks: Part I. Diagnosis and Evaluation. AAFP 2004;69:1665-74,1679-80.
• (3) Melissa Franklin et al. Is an outpatient workup safe for patients with a transient ischemic attack?. JFP 2004;53(7).