Medical Author: Benjamin C. Wedro, MD, FAAEM
Medical Editor: Melissa Conrad Stöppler, MD
The brain is an impressively wired computer. It stores information from input
through our five senses and sifts through the data; gets rid of frivolous
material and organizes the important stuff into short-term memory centers; and
finally rearranges the final product into long-term memory. The brain also
sends messages out electrically to the rest of the body, controlling movement
and position so that the body can take the brain where it wants to go.
Electricity is the key to its function, and sometimes it short circuits.
Seizures occur when parts of the brain becomes irritable and develop electrical surge. That surge can remain in a small area or it can spread to the whole brain. Normally, when we lift an arm, it is because part of the brain sends an electrical message through the spinal cord for the arm to move. The classic shaking of a seizure is witnessed when the whole brain fires, and the whole body moves. Usually the shaking is short-lived, because the brain doesn't like being irritated and it shuts itself down.
Every person has the potential to have a seizure. Usually the seizure threshold is high, and there needs to be an outside noxious stimulus to cause an electrical surge that is greater than that threshold for a seizure to occur. Seizures are often seen after head injuries - high fevers in children can also precipitate a seizure. In some people, the seizure threshold is set lower, and they may need medication to raise that threshold to prevent seizures.
After the seizure, it takes time for the brain to reboot, just like you computer. When it reboots, you can type as much as you want, but until the programs are ready to go, nothing is going to happen on the screen. Similarly, the brain needs time to reset itself and this post-ictal phase (the time immediately after a seizure) shows up as a period of confusion, sleepiness, or irritability.
U.S. Supreme Court Chief Justice Roberts had a seizure in July, 2007, (he also had one in 1993) and we were told that his doctors couldn't find a cause. So what were they looking for?
When a seizure occurs, the usual suspects are rounded up and considered as causes. Was there an infection that may have caused the irritability? Did part of the brain lose blood supply due to stroke, or did a tumor or mass cause the problem? Screening blood tests and CT or MRI scans of the brain may be helpful in sorting things out. One of the most important tests is an EEG or electroencephalogram, sort of like an EKG of the brain. By looking at the brain's electrical activity, the neurologist can sometimes find a short circuit focus.
The problem with seizures is not the one that was just completed, but if and when the next one might occur. Seizures are a common problem, and many people have an isolated, single event. For that reason, if all the tests are normal, people are given a freebie: one seizure, no treatment - just watch and wait what the future will bring. But if seizures recur, then treatment is necessary for prevention.
It's hard to predict the future in the watch and wait phase, so recommendations for limiting activities are important. People who have had a seizure don't drive, scuba dive, jump out of airplanes, or put themselves into positions where another seizure will put themselves or others in danger. The restrictions may last weeks or months depending on the situation.
For Justice Roberts, it is good news that no cause for the seizure was found. Decisions on further treatment, medications, and activity will be tailored to his situation just like any other patient. And just like any other patient, the expectation will be for him to return to a fully active life at the level where he was before the seizure occurred.
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