A stroke is an accident involving the blood vessels in the brain, and is technically known as a cerebral infarct or cerebrovascular accident (CVA). If a clot, or piece of material from elsewhere in the body, blocks an artery in the brain (cerebral thrombosis), or if an artery bursts in the brain, a stroke may occur. The risk of stroke is higher in those who smoke, have high blood pressure, high cholesterol levels, are diabetic, and drink alcohol to excess.
Any blood vessel in the brain may be involved, so any part of the brain may be damaged, and the area damaged determines the effects on that person’s body. The symptoms can therefore be very varied. If a motor area of the brain, which controls movement is affected, the patient becomes paralysed down the opposite side of the body because the nerves supplying the body cross over to the opposite side at the base of the brain (the right side of the brain controls the left arm and leg). Other patients may lose their memory, power of speech, become uncoordinated, unbalanced, start fitting, have strange smells, hear abnormal noises, lose vision, develop a sudden severe headache or any of dozens of other possibilities. The area of the brain affected may increase as a blood clot extends along an artery, or bleeding into the brain continues.