CVA stroke incident, vascular stroke, or stroke (CVA), is the rapid loss of brain function due to a disorder in blood supply to it. A CVA stroke incident may be due to ischemia (lack of blood flow) caused by obstruction (thrombosis, arterial embolism), or bleeding. As a result, the affected area of the brain can not function normally, and this may lead to the inability to move one or more limbs from one side of the body (hemiparesis or hemiplegia), inability to produce or understand speech (aphasia of transmission or intake), inability of vision from one side of the visual field (hemianopia), etc.
A CVA stroke incident is an urgent medical condition which can cause permanent neurological damage and death.
The most common risk factors for a CVA stroke incident are:
• Advanced age
• Arterial hypertension
• Previous stroke or transient ischemic attack (TIA),
• High cholesterol,
• Atrial fibrillation etc.
High blood pressure is the most important and controlled risk factor for vascular stroke.
CVA stroke incident - CLASSIFICATION
Vascular strokes can be classified into two major categories:
• Ischemic type: these are caused by interruption of blood supply to the brain, and
• Haemorrhagic type: those result from rupture of a blood vessel or an abnormal vascular structure (vascular malformations or vascular dysplasia).
Approximately 87% of strokes are caused by ischemia, while the remainder from bleeding. Some bleeding develops in a previous ischemic area and it is unknown how many bleedings actually start as an ischemic stroke.
In an ischemic stroke, the blood supply to a part of the brain decreases, leading to brain dysfunction in this region. There are four reasons why this may happen:
• Thrombosis (blockage of a vessel by a blood clot formed locally)
• Embolism (blockage of a vessel due to a blood clot coming from another area eg carotid artery, heart)
• Systemic hypo-supply (generalized reduction of blood supply to the brain, eg, shock)
• Venous thrombosis
However, a large percentage of a CVA stroke incident, approximately 30-40% of the total, are of unknown aetiology.
There are various classification systems for acute ischemic vascular brain stroke.
CVA stroke incident – TREATMENT
The treatment of a CVA stroke incident is multifactorial and requires specialized centres. Collaboration of Internist, Neurologist, Interventional Radiologist and Neurosurgeon is essential for an optimal diagnostic and therapeutic approach. Speed in intervention is required because the sooner the patient is treated, the better the prognosis.