2010 BC Guide in Determining Fitness to Drive

Chapter 20: Cerebrovascular DiseaseBACKGROUND20.1 About cerebrovascular diseaseCerebrovascular disease is disease involving the blood vessels supplying the brain.Transient ischemic attack (TIA)A transient ischemic attack (TIA) is a brief episode of neurological dysfunction caused by atemporary state of reduced blood flow to the brain. The symptoms of a TIA are similar to aCVA (described below) but are temporary, typically lasting less than one hour and no more than24 hours. The most common cause of a TIA is a blood clot. A TIA is considered to be awarning sign that a CVA may be imminent. The risk of having a CVA is 10% in the first 90days following a TIA, with a cumulative 3 year risk of 25%.Cerebrovascular accident (CVA)A cerebrovascular accident (CVA) or stroke is defined as rapidly developing clinical signs offocal or global disturbance of cerebral function, with symptoms lasting 24 hours or longer, orleading to death, with no apparent cause other than of vascular origin. A CVA can be classifiedas either ischemic or hemorrhagic. Ischemic CVA refers to a CVA caused by thrombosis orembolism, and accounts for 85% of all CVAs. Hemorrhagic CVAs are caused by anintracerebral hemorrhage (bleeding within the brain) or subarachnoid hemorrhage (bleedingbetween the inner and outer layers of the tissue covering the brain).The symptoms of a CVA vary depending on what part of the brain is affected. The mostcommon symptom is weakness or paralysis of one side of the body with partial or complete lossof voluntary movement or sensation in a leg or arm. There can be speech problems and weakface muscles. Numbness or tingling is very common. A CVA can affect: balance vision swallowing breathing, and level of consciousness.Visual or spatial neglect is a common consequence of a CVA. With neglect, damage to the braincauses an individual to ignore one side of their visual field or their body, even if they retainsensation and function. Neglect is usually a result of a stroke affecting the right hemisphere ofthe brain, therefore causing neglect of the left side. Visual neglect occurs in 33 to 85% of allstrokes affecting the right hemisphere.239