Transient ischaemic attack
A focal neurological deficit from transient cerebral ischaemia that resolves completely within 24 hours, usually much sooner, because the occlusion is brief enough that no tissue infarcts, but it is a warning sign of impending full stroke that demands the same urgent work-up.
First principles
TIA is stroke pathophysiology that reverses before infarction occurs
The mechanism is identical to ischaemic stroke: a thrombus or embolus transiently occludes a vessel, causing focal hypoperfusion and a matching deficit. Flow is restored, because the clot lyses spontaneously or moves on, before the ischaemic core progresses to irreversible infarction, so tissue and function recover completely. This is why a TIA cannot be diagnosed until the deficit has fully resolved and why imaging often shows nothing.
Educational content pending clinical review. Not medical advice.