The frontal, parietal, and temporal lobes are the most prone to suffer from an ischemic stroke due to their shared blood supply. The frontal lobe is located within the anterior cranial fossa, whereas the temporal lobe is situated in the middle cranial fossa. The middle cerebral artery (MCA) is the region of interest as this is the most common site for ischemic strokes. The MCA consists of four sections. The M1 segment consists of lenticulostriate vessels which irrigate the basal ganglia. The M2 segment extends anteriorly on the insula, and the M3 segment expands laterally and exteriorly from the insula towards the cortex. Finally, the M4 segment supplies the cortex at the Sylvian fissure. The frontal, parietal, and temporal lobe are all supplied
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If the neurological deficits last for less than 24 hours, it is said to be a transient ischemic attack. There are three types of ischemic stroke; thrombotic, embolic, and hypoxic. Thrombotic ischemic stroke results from the rupture of an atherosclerotic plaque. Embolic ischemic strokes are caused by an embolus occluding a blood vessel. Finally, hypoxic ischemic strokes are due to hypoxemia or cerebral hypoperfusion. Other causes of ischemic stroke include atrial fibrillation, sickle cell disease and ventricular tachycardia. The pathophysiology of an ischemic stroke first involves a decrease in oxygen, glucose and other nutrients due to ischemia. Due to decreased oxygen, the normal process of oxidative phosphorylation does not occur, and thus ATP is not generated. ATP reliant ion transporting pumps cannot function, causing the neuron to become depolarised and allowing extracellular ions to flow into the cell. Thus, intracellular calcium ions increase resulting in the exocytosis of the excitatory neurotransmitter, glutamate, resulting in excitotoxicity. Harmful substances are produced, such as free radicals, resulting in infarction and liquefactive necrosis of nervous tissue. The penumbra is a region of cerebral parenchyma that is at risk of infarction, but is still salvageable if blood flow is restored to the region.
The symptoms of ischemic stroke mirror the region of brain tissue undergoing hypoxia, and can vary from minor to severe symptoms. The symptoms can last from a few seconds, to a few minutes and can become permanent if region undergoes infarction. Such symptoms include hemiparesis, dizziness, vertigo, diplopia, facial drooping, weakness in the arms or legs, slurred speech, severe headaches, gait abnormalities, and loss of
If the neurological deficits last for less than 24 hours, it is said to be a transient ischemic attack. There are three types of ischemic stroke; thrombotic, embolic, and hypoxic. Thrombotic ischemic stroke results from the rupture of an atherosclerotic plaque. Embolic ischemic strokes are caused by an embolus occluding a blood vessel. Finally, hypoxic ischemic strokes are due to hypoxemia or cerebral hypoperfusion. Other causes of ischemic stroke include atrial fibrillation, sickle cell disease and ventricular tachycardia. The pathophysiology of an ischemic stroke first involves a decrease in oxygen, glucose and other nutrients due to ischemia. Due to decreased oxygen, the normal process of oxidative phosphorylation does not occur, and thus ATP is not generated. ATP reliant ion transporting pumps cannot function, causing the neuron to become depolarised and allowing extracellular ions to flow into the cell. Thus, intracellular calcium ions increase resulting in the exocytosis of the excitatory neurotransmitter, glutamate, resulting in excitotoxicity. Harmful substances are produced, such as free radicals, resulting in infarction and liquefactive necrosis of nervous tissue. The penumbra is a region of cerebral parenchyma that is at risk of infarction, but is still salvageable if blood flow is restored to the region.
The symptoms of ischemic stroke mirror the region of brain tissue undergoing hypoxia, and can vary from minor to severe symptoms. The symptoms can last from a few seconds, to a few minutes and can become permanent if region undergoes infarction. Such symptoms include hemiparesis, dizziness, vertigo, diplopia, facial drooping, weakness in the arms or legs, slurred speech, severe headaches, gait abnormalities, and loss of