TIA

TIA Definition

Transient episode of neurologic dysfunction caused by CNS ischemia (brain, cord, retina) without acute infarction.  Older definition of < 24 hrs of sxs still in wide use. Many of these actually do have small CVA when imaged w/ MRI.

Presentation

  • Sudden onset
  • “Negative” symptoms (e.g. deficit)
  • Focal symptoms – maps to a central location (brain or cord)/vascular territory (i.e. not global weakness)

DDx

Hypoglycemia, seizure, migraine/migraine aura, syncope, electrolyte abnormality, liver disease, transient global amnesia, MS, intermittent compression of a peripheral nerve

Workup

ECG: Evaluate for atrial fibrillation or other dysrhythmia as well as evidence of prior MI which could predispose to mural thrombus

Labs: At least basic chemistry and CBC for hypoglycemia, electrolytes, thrombocytosis – also consider LFTs, troponin.

Brain imaging: At least CT. MRI w/ diffusion weighted imaging probably more helpful prognostically in that in can show evidence of ischemia

Vascular imaging: Can be angiography added to CT/MRI or can be carotid ultrasound. Evaluating for carotid stenosis mainly. Also need to consider the vascular territory of concern – e.g. crossed sensory findings or vertigo implies a posterior circulation problem and needs imaging of vertebral arteries/PCAs

Echo: Less routine. Can evaluate for PFO and for mural thrombus as treatable etiologies of central embolic events.

Risk and Disposition

  • 3 mo risk of CVA after TIA is probably ~ 15% – and 50% of those will be w/in 48 hrs
  • ABCD2 score is imperfect (poor performance on validation analyses) but is something to start with or document at least
  • All patients need “urgent” evaluation – should be worked up w/in 48 hrs – but not necessarily hospitalized. Per AHA neuroimaging should be w/in 24 hrs.
  • Patients w/ abnormal brain MRI (i.e. evidence of ischemia) after TIA should also be hospitalized b/c of much higher risk of subsequent CVA

2009 American Heart Association and American Stroke Association (AHA/ASA) guidelines – reasonable to hospitalize patients with TIA who present within 72 hours of symptom onset and any of the following:

●ABCD2 score of ≥3

●ABCD2 score of 0 to 2 and uncertainty that the diagnostic workup can be completed within two days as an outpatient

●ABCD2 score of 0 to 2 and other evidence that the event was caused by focal ischemia

Treatment

  • Antiplatelet – Reasonable to start all w/o a contraindication on aspirin 81 mg daily
  • Statin – Reasonable to start or can start w/ PCP
  • Anticoagulation – anyone w/ atrial fibrillation needs anticoagulation – either started from ED or admitted to start
  • Blood pressure – Need close PCP f/u for BP management
  • Lifestyle – smoking cessation probably most important intervention