Stroke, also called brain attack, occurs when an area of the brain does not receive blood supply. This results in death of the cells in the brain, and due to this the functions controlled by the affected part of the brain, such as muscle control, are also affected.
Brain aneurysm, on the other hand, is a weak area in the blood vessel in the brain that is ballooned, and can rupture or leak leading to bleeding into the brain. The aneurysm most often ruptures into the membranes surrounding the brain leading to haemorrhage.
Stroke is the death or damage of brain cells due to impaired blood supply. This condition occurs due to block in the artery or due to hemorrhage. When the disruption is due to a block in the artery, then it is called ischemic stroke and when the disruption is due to bleeding in the brain or in the membranes surrounding the brain, then it is called hemorrhagic stroke. A hemorrhagic stroke can be due to a burst aneurysm.
The damage caused by the stroke is largely determined by the area of brain that was cut off from blood and oxygen supply and the duration of the cut off. The longer the duration of cut off of blood and oxygen supply, the more the damage caused by the stroke. When blood supply is disrupted only for a very short duration, then it is called a mini stroke or transient ischemic attack (TIA). One should immediately address a TIA as well, as it is a warning sign for a stroke to come.
An aneurysm is an excessive localised enlargement of an artery caused by weakness in the wall of an artery. It is commonly seen in the common carotid artery but it can also occur in the other arteries of the brain. In case any of these weakened arteries burst, then the result is a brain hemorrhage. There are many reasons for the weakness and ballooning of an artery and subsequent hemorrhage.
One of the major reasons is hardening of the arteries due to fatty deposits, called atherosclerosis. The major risk factors include cigarette smoking and high blood pressure. Also infection to the artery, congenital defect, and traumatic injury can also cause weakness in the walls of the arteries.
Most of the aneurysms do not cause any symptoms until a hemorrhage occurs, but some symptoms may be noticed if the size of the aneurysm is large enough to press against other organs or tissues. For instance, the patient may experience headaches before the rupture.
X-rays, ultrasound, CT scans, and MRIs are the diagnostic tests that can help in detecting an aneurysm. A thorough study of these tests can help in deciding if a surgery is required or just regular follow-ups is sufficient in the management of the aneurysm.
One must note, however, that if an aneurysm bursts, then it is a medical emergency, and the patient needs to be taken to the hospital immediately for treatment.
In conclusion, a stroke is the result of, among various reasons, a cerebral hemorrhage, which can be the result of an aneurysm.