Penumbra (medicine)

A penumbra ( Latin : penumbra ) is the area of a cerebral infarction that immediately adjoins the central necrosis zone and still contains viable cells.

Blood flow is reduced in this area, which can vary in size. The tissue is only incompletely damaged here. The relative lack of oxygen ( hypoxia ) temporarily leads to a complete functional failure of these tissue parts. The tissue in the penumbra can be further destroyed in the further course or it can recover again. The destruction of the cells in this zone occurs either through excitotoxicity ( apoptosis ) or through acidosis ( necrosis ), induced by glycolysis and the subsequent formation of lactate .

A major goal of therapeutic intervention in ischemic cerebral infarction is to restore adequate blood flow in the penumbra. In this way, the extent of the infarction should be kept within limits, which is an essential factor for the further prognosis. However, a new study shows that extending the time window of endovascular therapy when the penumbra is present does not have any prognostic advantages.

The penumbra can be detected diagnostically by a so-called mismatch in the diffusion and perfusion weighting of the magnetic resonance imaging of the skull (cMRI).

literature

Karl F. Masuhr, Marianne Neumann: Dual series Neurology Thieme Verlag, Stuttgart, 2005, ISBN 3-13-135945-5

Individual evidence

↑ CS Kidwell, R Jahan, J Gornbein, JR Alger, V Nenov, Z Ajani, L Feng, BC Meyer, S Olson, LH Schwamm, AJ Yoo, RS Marshall, PM Meyers, DR Yavagal, M Wintermark, J Guzy, S. Starkman, JL Saver. A Trial of Imaging Selection and Endovascular Treatment for Ischemic Stroke. NEJM. doi : 10.1056 / NEJMoa1212793 .

[1] CS Kidwell, R Jahan, J Gornbein, JR Alger, V Nenov, Z Ajani, L Feng, BC Meyer, S Olson, LH Schwamm, AJ Yoo, RS Marshall, PM Meyers, DR Yavagal, M Wintermark, J Guzy, S. Starkman, JL Saver. A Trial of Imaging Selection and Endovascular Treatment for Ischemic Stroke. NEJM. doi : 10.1056 / NEJMoa1212793 .