趙啟明醫生醫務所         Dr Leo Chiu, Central Vascular Clinic

What is stroke? A stroke occurs when blood supply to the brain is interrupted by a blood clot or when a blood vessel bursts. Brain cells deprived of fresh blood (also known as ischemia) will be damaged. If ischaemia last for more than a few minutes, the brain cells die (known as infarction). This could cause permanent loss of brain function (stroke), or a "transient ischemic attack" (TIA), which implies a temporary interruption of brain function which recovers within 24 hours.   Symptoms of stroke   Stroke happens suddenly, as inability to normally move an arm or leg with sudden loss of balance or coordination. The inability to feel (numbness) is also a common symptom. If the speech centre in the brain is affected speech becomes jumbled. Sometimes there is transient loss of vision of part of the visual field (Amaurosis Fugax).