Evidence Based Medicine: My patient just had a transient ischaemic attack. Can I predict his risk for stroke? Is stroke inevitable or preventable?

Transient Ischaemic attack or TIA has traditionally been defined as a discrete neurological deficit lasting for 24 hours. The new definition of a TIA is that of a brief neurological dysfunction caused by focal brain or retinal ischaemia and lasting for 1 hour without signs of infarction on brain MRI. Hence, a tissue based rather than a time based definition is being proposed.