Stroke is the second leading cause of death worldwide and survivals often being disabled with serious cognitive difficulties affecting social life as well as the ability to perform work. This is except for the suffering of the patients and the close relatives also extremely costly to society and the healthcare system. Without new efficient treatment of stroke patients, the cost to care for American stroke victims, during the next 45 years will exceed $2.2 trillion.
Stroke is classified into two major categories. Ischemic that causes interruption of blood supply and haemorrhagic that results from rupture of a blood vessel. Both induce rapid loss of brain function caused by disturbances in blood supply. Ischemic stroke is by far the most common form with 87% while intracerebral haemorrhage accounts for 9% and 4% are due to subarachnoid haemorrhage.
The pathophysiology of ischemic stroke is complex and the patient recovery is dependent on the length in time that neuronal tissues are deprived from blood supply. Brain tissues deprived of oxygen for more than three hours will cause irreversible damage. The pathophysiology includes exciotoxicity mechanisms, inflammatory pathways, oxidative damage, ionic imbalances, apoptosis, angiogenesis and endogenous neuron protection. Additionally when white blood cells re-enter a previously hypo-perfused region via returning blood, they can occlude small vessels, producing additional ischemia.
Different strategies to manage stroke is; to identify risk groups for preventive treatment; development, implantation and dissemination of evidence-based clinical practice guidelines in order to set a standard for stroke management through the continuum of care with early treatment that is fundamental to improve the outcomes following an ischemic stroke attack.
One of two approved treatment today is IV administration tissue plasminogen activator (tPA) that will induce thrombolysis this may remove the clot and restore blood supply to the brain tissue. The other method is to mechanically remove the clot, to restore blood supply.
Other approaching methods are in early phase research and some in clinical trials. New potential therapies of interest include administration of neuroprotective agents, cooling of the ischemic brain and the use of stents to revasculate occluded arteries.
- Early treatment by removing mechanical hinders is the first goal to improve the outcomes following an ischemic stroke attack.
- The second goal is to administer neuroprotective agents before or immediately after clot is removed. To save ischemic neurons in the brain from irreversible injury, including apoptosis.
- One action of research-clinical trial neuroprotective agents limits acute injury to neurons in the ischemic penumbra.
- Other neuroprotective agents prevent potentially detrimental events associated with return of blood flow.