Johnson's condition was caused by a congenital arteriovenous malformation, which is an abnormal cluster of blood vessels that can form in the brain before birth. A person with this condition is at an increased risk of suffering from a hemorrhage, or bleeding inside the brain. It is estimated that one in every 200 to 500 people have this condition and more than 50 percent will cause a brain hemorrhage.
A brain hemorrhage can also be caused by a stroke or an aneurysm, both of which affect blood flow to the brain. Strokes occur when blood flow to the brain is interrupted, either due to bleeding or a blockage within an artery supplying blood to the brain. Aneurysms, on the other hand, occur when a weakened part of a brain artery bulges, which increases the risk of it bursting, leading to a brain hemorrhage.
These conditions are very serious because they all cause changes in the blood flow to the brain, possibly resulting in brain damage or even death.
Fortunately, there are warning signs to watch out for. According to the American Heart Association, the following are potential symptoms of an impending brain hemorrhage or stroke:
- Sudden numbness or weakness on one side of the body, including, but not limited to the face, arms or legs.
- Sudden confusion, trouble speaking or understanding.
- Sudden difficulty in seeing from one or both eyes.
- Sudden difficulty walking , which may include dizziness and or loss of balance and coordination.
- Sudden, severe headache with no known cause.
Johnson, in fact, had difficulty speaking to reporters shortly before he was admitted to the hospital. While he still has a long road of recovery ahead of him, Johnson was lucky in that he noticed that he was having unusual symptoms and immediately sought a doctor's care.
If you experience any of these symptoms, immediately call 911. The sooner you get to a hospital, the better chance you have of a full recovery.