First we have to be clear where the clot is? If it is inside the vessel (blood pipe) then a part of the brain gets damaged and paralysis
occurs. Other type is when bleeding occurs in the brain and clot forms. This causes pressure over the surrounding area and causes paralysis etc. Clot during one attack usually grows for few minutes to hours only. However recurrent attacks may occur following 1st attack. For most patients medicines are first treatment option and surgery is required in only a selected few patients. It is not a progressive illness and if initial phase tides over then survival can be expected to be good.