Ischaemic Stroke

In ischaemic stroke, arterial occlusion leads to the abrupt cessation of distal blood flow.

Brain tissue receiving little or no blood flow is known as the ischaemic core, and is made up of cells that die rapidly.

Typically, 1.9 million neurons are lost for every minute that a stroke goes untreated.

Surrounding the ischaemic core is the ischaemic penumbra. This is tissue that is hypoperfused, functionally impaired and at risk of infarction, but it may be saved if reperfused.

The penumbra contains electrically inexcitable, but viable, cells. The duration of ischaemia, as well as the absolute flow, plays a crucial role in determining the fate of the cells in this penumbra.

The longer that penumbral brain tissue remains untreated, the greater is the chance of it undergoing infarction.