What is the difference between acute ischemic stroke and ischemic stroke?

New onset: An acute ischemic stroke is one whose onset was within the past 24 hours or less. An ischemic stroke refers to brain damage due to an obstructed artery, whereas a hemorrhagic stroke is one in which brain damage occurs as the result of bleeding (hemorrhage).

Acute - Sudden Onset: Acute stroke refers to a stroke that has just occurred. Ischemic stroke may be hyperacute (based on sudden onset neurological symptoms and imaging findings, MRI and perfusion study) and potentially treatable, acute (1-7 d), subacute (7-21 d), and chronic (>21 d).