Democratic Sen. Tim Johnson was in critical condition recovering from emergency brain surgery Thursday, creating political drama over whether his illness could cost Democrats newly won control of the Senate. The South Dakota senator, 59, suffered from bleeding in the brain caused by a congenital malformation, the U.S. Capitol physician said. He described the surgery as successful. The condition, usually present at birth, causes tangled blood vessels that can burst.
Okay, now we know more: this is very serious. This is the result of a rupture of a cerebral aneurysm. These are indeed congenital malformations: not everybody has them, and if you do, you might have one or 100. They might never break or they might. It's scary in a big way; one neurologist I know describes them as 'a time bomb inside your head'.
If one leaks, you get symptoms of a TIA or stroke. If an aneurysm really opens up, it's a hemorrhagic stroke and death/near death within a couple of hours. Frequently one has what is called a 'subarchnoid hemorrhage' (SAH, bleeding into a space between the brain and a lining layer of the brain) which is especially serious. The damage comes from the blood, the loss of blood supply to that part of the brain, the direct compression of brain tissue, and the increased pressure inside the head which squeezes the brain and brainstem further. The brain really, really doesn't like any of this.
Emergency treatment includes therapies to lower the pressure and fix certain metabolic problems that might occur, followed by emergency surgery to fix the aneurysm and relieve the pressure better. Sometimes radical surgery is required, and sometimes it has to be repeated.
If the patient recovers you go on a hunt to find other aneurysms, generally with what is called a 'digital angiogram'. If you find more, you consider fixing them now so that they don't rupture in the future. Whether one goes ahead with surgery to do that can be modified by age and other medical conditions.
However, recovery is not certain, and a ruptured aneurysm has, even with the best medical care, a very high morbidity and high mortality rate (I've seen numbers > 50%). Re-bleeding after surgery is a common, serious problem. Surviving patients are frequently left with serious neurologic deficits, and other complications may occur. Patients with an aneurysm and SAH have the highest mortality rates and lowest full recovery rates. |
| Addendum at 1645 CST: I'm reading at other sources that this wasn't an aneurysm but rather an arteriovenous malformation. The difference: the former is a weakness and 'bulge' in an arterial wall; the latter is an abnormality that causes arteries and veins to join together in an abnormal way. The pressure from the arterial side can cause the abnormal vessels to blow, and it's totally unpredictable. The clinical consequences, however, are the same and are as I've noted above. |
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