Study shows area undamaged by stroke remains so, regardless of time stroke is left untreated

A new study looked at a group of untreated acute stroke patients and found that there was no evidence of time dependence on damage outcomes for the penumbra, or tissue that is at risk of progressing to dead tissue but is still salvageable if blood flow is returned in a stroke, but rather an association with collateral flow — or rerouting of blood through clear vessels.