Penumbra (medicine)

As penumbra (Latin: penumbra ) is called at a stroke the area immediately adjacent to the central necrotic zone and still contains viable cells.

In this area, which may have different sizes, the blood flow is reduced. The fabric is here damaged incomplete. Due to the relative lack of oxygen (hypoxia ) leads temporarily to a complete loss of function of these tissue components. The tissue in the penumbra could be destroyed in the course partly or recover. The destruction of the cells in this zone either via excitotoxicity (apoptosis) or acidosis (necrosis ) induced by glycolysis and the subsequent formation of lactate.

A major goal of therapeutic intervention in the ischemic stroke is the restoration of an adequate blood flow in the penumbra. In this way, the extent of the infarct should be kept within bounds, which is an essential factor for the further prognosis. However, a new study shows that the extension of the time window of endovascular therapy for existing Penumbra brings no prognostic benefits.

Diagnosis, the penumbra can be detected by a so-called mismatch in the diffusion and Perfusionswichtung magnetic resonance imaging of the skull ( cMRI ).