Targeting the Ischemic Penumbra

Targeting the ischemic penumbra.

BACKGROUND In the last 3 decades, and from a therapeutic point of view, the classical concept of ischemic penumbra based on hemodynamic and electrophysiological parameters has loosened up the rigidity of therapeutic windows in acute stroke management. Thirty years later, the ischemic penumbra is an evolved concept that presents more applications. Thus, the ischemic penumbra is a diagnostic targ...

The cerebral ischemic penumbra.

When neuronal activity is suppressed by ischemia of sufficient severity, maintained for a long enough period of time, permanent clinical deficit can be accompanied by radiographic signs of cerebral infarction and histological evidence of ischemic damage. Recent work suggests that this is not an all-ornone event. Between the most densely ischemic region and the more normally perfused brain, an i...

Molecular identification of the ischemic penumbra.

Review of results of experimental and clinical studies indicates that the penumbra of physiologically impaired but potentially salvageable tissue surrounding the central core of focal cerebral ischemia that develops shortly after onset of major conducting vessel occlusion is complex and dynamic with severity and duration thresholds for hypoxic stress and injury that are specific to tissue site,...

Thresholds in cerebral ischemia - the ischemic penumbra.

COMPLETE ARREST of the cerebral circulation leads within seconds to cessation of neuronal electrical activity and within a few minutes to deterioration of the energy state and ion homeostasis. Depletion of high energy phosphates, membrane ion pump failure, efflux of cellular potassium, influx of sodium, chloride and water, and membrane depolarization occur swiftly. If such chaos persists for lo...

Acute ischemic stroke: time, penumbra, and reperfusion.