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.