Cerebrovascular Pathophysiology and its Diagnosis

Stroke is a type of cerebrovascular disease involves central nervous system. It occurs with sudden due to the burst of cerebral arteries, haemorrhage, or other particles which leads to ischemia and to focal brain dysfunction [1]. Nerve cells depleted oxygen in the involved vascular territory will be functionally disturbed and die if the circulation is not promptly restored. Two main mechanisms leads to ischemic stroke are occlusion and haemodynamic impairment. These two situations reduce the cerebral perfusion pressure and leads to cellular death. The blood flow in the brain can be maintained by auto-regulation of cerebral arteries and collateral circulation within certain limits. When occlusion of an artery develops, blood flow in the periphery of the infarct core is reduced but still it remains sufficient to avoid structural damage, so that the functional modifications of cells may be reversible if circulation is restored. This ringlike area of reduced blood flow around the ischaemic centre of infarct has been termed penumbra as an analogy of the half-shaded part around the centre of a solar eclipse. It explained the functional improvement occurring after stroke. The neurons which are surviving in this critical area of infarct are reduced at blood flow and may function again as soon as the blood flow and oxygen delivery is restored.