What is a penumbra stroke?
In pathology and anatomy the penumbra is the area surrounding an ischemic event such as thrombotic or embolic stroke. Immediately following the event, blood flow and therefore oxygen transport is reduced locally, leading to hypoxia of the cells near the location of the original insult.
What is penumbra in the brain?
Simply stated, the penumbra is the part of the brain that is sandwiched between brain regions committed to die and those that receive enough blood to communicate. Therefore, it is ischemic brain tissue that has just enough energy to survive for a short time but not enough to communicate and function.
What is ischemic penumbra and why is it important?
“Penumbra” is the term used for the reversibly injured brain tissue around ischemic core; which is the pharmacological target for acute ischemic stroke treatment (Astrup et al. 1981a). The goal to treat ischemic stroke is to salvage the penumbra as much and early as possible.
What happens to neurons after a stroke?
When a stroke causes a blood vessel to block or rupture, the neurons in the brain are deprived of blood. Without blood, these cells starve and die. This damage triggers different physical and mental changes in stroke victims. Fortunately, damaged brain cells are not beyond repair.
What causes an embolic stroke?
Embolic strokes are usually caused by a blood clot that forms elsewhere in the body (embolus) and travels through the bloodstream to the brain. Embolic strokes often result from heart disease or heart surgery and occur rapidly and without any warning signs.
How does stroke affect neuron function?
Nerve cells in the brain tissue communicate with other cells to control functions including memory, speech and movement. When a stroke occurs, nerve cells in the brain tissue become injured. As a result of this injury, nerve cells cannot communicate with other cells, and functions are impaired.
What cells proliferate after a stroke?
Spontaneous recovery following stroke may come 1/from the capacity of endogenous stem cells to proliferate into neurogenic niches, migrate toward the damaged parenchyma, and differentiate into neurons or 2/from parenchymal cells that proliferate, dedifferentiate into neuronal cells and survive to replace dead neurons.
Where is the penumbra located?
It is the dark center of the eclipse shadow. The second shadow is called the penumbra (pe NUM bruh). The penumbra gets larger as it goes away from the sun.
What is the ischemic penumbra and why is it important?
The concept of the ischemic penumbra is an important one for both basic investigators of cerebral ischemia and for clinicians who treat stroke patients.
What happens to the brain after a stroke?
Within minutes of a focal ischemic stroke occurring, the core of brain tissue exposed to the most dramatic blood flow reduction is fatally injured and subsequently undergoes necrotic cell death.
What do we know about apoptosis after cerebral ischemia?
Although many of the key apoptotic proteins have been identified, our understanding of the complex underlying mechanisms remains poor and hence treatment of stroke patients by manipulating apoptotic pathways remains a daunting task. However, recent advances in the field have helped broaden our knowledge of apoptosis after cerebral ischemia.
Does stroke-induced apoptosis occur in nonneuronal cells?
Further to the simplistic concept that stroke-induced apoptosis occurs predominantly in neurons and is caspase-dependent, accumulating evidence now indicates that apoptosis is prevalent in nonneuronal cells and that caspase-independent mechanisms also play a key role.