ischemic penumbra

ischemic penumbra

an area peripheral to one of ischemia where metabolism is active but blood flow is diminished.
[L. paene, almost, + umbra, shadow]

ischemic penumbra

an area of moderately ischemic brain tissue surrounding an area of more severe ischemia. Theoretically, blood flow to this area may be enhanced in order to prevent the spread of a cerebral infarction.

ischemic penumbra

Neurology An ischemic zone in the brain at risk of infarction, which lies in a 'no-man's land' between a zone of low blood flow–< 25 ml/100 mg brain tissue/min and a zone where brain tissue is undergoing necrosis–flow–< 8 ml/100 mg/min. Cf Hemorrhagic stroke.
References in periodicals archive ?
Results: SWI is of guiding significance for thrombolytic therapy in stroke patients, it can predict the location and length of thrombus and ischemic penumbra.
Caption: FIGURE 1: CT perfusion scan showing ischemic penumbra in the right cingulate gyrus (arrows pointing out affected area).
As polypeptide nerve growth factors, VEGF and TGFpi were important factors in promoting angiogenesis, VEGF was an endothelial cell mitogen with strong in vitro activities, and could specifically act on the endothelial cells and increase the vascular permeability and angiogenesis in vivo, Once the angiogenesis occurred, the blood supply towards the ischemic area was promoted, which would help to prevent the neuronal apoptosis in the ischemic penumbra, reduce the infarcted size, reduce the cerebral ischemic damages and cerebral edema [13].
Later, inducible NOS (iNOS) contributes to high production of nitric oxide that plays an important role in neurodegeneration of the ischemic penumbra area.
The inhibition of cerebral blood flow distal to the clot results in a core of dead tissue with a surrounding viable ischemic penumbra (Liebeskind, 2010).
Neuroprotection refers to the concept of applying a therapy that directly affects the brain tissue to salvage or delay the infarction of the still-viable ischemic penumbra, rather than reperfusing the tissue (Jauch et al.
It leaves an area of damage called an ischemic penumbra.
The ischemic penumbra is commonly defined by subtracting the brain region with restricted diffusion from the region associated with low cerebral blood flow.
Following stroke there is resolution of oedema and reperfusion of ischemic penumbra.
Specifically, the notion of diffusion/perfusion mismatch (DPM) has gained substantial interest as an effective tool to reveal the presence of ischemic penumbra [11, 12, 15, 18].
Specific topics include: burden of stroke and risk factors, implications of strike pathophysiology and the ischemic penumbra, neuroplasticity and neurorecovery, classification of stroke subtypes, neuroimaging, management of acute ischemic stroke, and medical treatment for secondary stroke prevention.
The ischemic penumbra represents part of the hypoperfused region associated with focal brain ischemia that potentially can be salvaged by timely intervention.