Most of my head-injured patients don't have seizure disorders (studies suggest this happens in 5 percent of head-injured people). However, it happens with enough frequency that people should be aware of it. When most people think of someone having a seizure, they think of someone who may fall to the ground and shake all over. When we see that happen in a store or restaurant, many people are frightened by it. In a head injury, a seizure tends to happen at two periods in time (but it can also happen at any time). It happens sometimes within hours or days of the accident itself. You may be in a hospital when this first occurs. A second point in time is nine months to one year following the accident.
What is a seizure? Let's think about the brain again. We know that the brain can get a scar or bruise on it because it's been jolted. With time, the bruise will go away and a scar will start to heal. Do you have any old scars on your body? If you feel them, you may notice that they're a little bit more solid or firm than the rest of the skin. The scar is always a little bit thicker and tougher than normal skin. In order to close a wound, the body sends resources to seal it. It's kind of like glue that holds your skin together. The same type of thing happens with the brain. When the brain gets a scar, the scar tends to harden over time. Some of the scars are actually rather soft at first, and with time they start to harden up a bit. The brain doesn't like that hardening and the scar starts to irritate the cells (neurons) around it Neurons are these tiny wires that make the brain work. These are like wires in a computer, except the wires in a computer are like giant pipes compared to these small neurons. Remember we have 100 billion of these neurons in our brain. It takes a microscope to see them. Imagine a room full of electrical wires. Although most wires are coated with insulation, imagine having a room full of uncoated wires. If I were to throw a wrench in a room with uncoated wires, there'd be kind of a short in the wiring. Basically this scar tissue is like putting a metal rod across open wires. That scar tissue takes six to nine months to build.
We talked about a short in the wire, but it's a little bit more complicated than that. Visualize a room full of mouse traps. Instead of putting cheese in the mouse trap, we put a ping-pong ball on each trap, and there's not a bit of space in this entire floor where I haven't put a mouse trap and a ping-pong ball. What if I just throw one ping-pong ball into that room? What's going to happen? It's going to hit one, which will bounce, hit two, which will hit four, which will hit eight and before long, the entire room has got ping-pong balls flying in it. That's a little bit like what happens with a seizure. Irritation in the brain may start at one area of the brain and then spread until it eventually takes over the entire brain.
Let's talk about different kinds of seizures. Probably the one that we're most aware of is called a Grand Mal seizure. This is the one that affects the whole body. The person begins to shake all over and may fall to the ground. This can cause injuries, including even a second head injury just from falling and hitting the head on a desk, table, or the hard ground. What if you're driving and you have a Grand Mal seizure? You're not going to be able to control your movements and your car will run into something. In the state of Michigan, you cannot drive a car unless you have been seizure-free for six months.
Seizures sometimes give off a warning sign before they start. Sometimes it'll feel like a tingling sensation in the stomach. Some people may begin to see bright lights or stars. Some people may smell something (like the smell of burning rubber). Suddenly, they just find themselves lying on the floor. The warning signs of a seizure are called "auras." Not everybody gets a warning sign. Sometimes, you're just walking along andbang!--the seizure hits you.
Some of my patients develop what are called simple or partial seizures. A simple seizure can be just a simple movement. A hand can begin to move uncontrollably for a few seconds to a minute. It's important to note that not all of these movements are seizures. For example, we've all had moments when we're tired or sick, when part of our face starts to twitch. That's not a seizure, it is just a spasm of a muscle. That's not a bad thing; it happens to a lot of people. Following an accident, you may start to get abnormal twitching. You must tell your doctor, who can figure out whether it's a muscle twitch or a seizure disorder.
There's also what's called complex partial seizures. They involve short but complicated activity. I'll give you an example. There was a college professor whose entire seizure involved him saying the words "class dismissed." He would walk into his lecture hall, and five minutes into his lecture, would suddenly say "class dismissed"--then he'd realize there was no one in his classroom. This is a seizure that involves a more complex activity.
What's a common sign of a seizure? For the majority of people who have seizures, there's one symptom that follows having a seizure--a very intense feeling of fatigue. They could be just waking up in the morning, have a little movement with their arm, and minutes later they are asleep. Some people who've had Grand Mal seizures or even partial seizures will literally lie down on the floor and be asleep within minutes.
A doctor who suspects that you have a seizure disorder will order a test called an EEG (electroencephalogram). They glue little wires over your head and connect them to a machine that measures electrical activity in your brain. Each of the wires measures little tiny bits of electricity generated by the brain. If you look at an EEG while it's recording, there'll be a bunch of needles jumping up and down over a long piece of paper. Remember all those billions of neurons? They all generate a little bit of electricity. Put a few billion together and you start to get some voltage (estimated to equal a 60 watt light bulb).
Getting an EEG is not a lot of fun. It's not painful, but it's basically annoying. Why is it annoying? Many doctors want you to stay up the entire night before. They won't let you sleep or they let you sleep for just a few hours before you go in for the test. Why do they want you to do that? Ever bring your car into a mechanic when its been making a really nasty noise, only to have it not make the noise when the mechanic is looking at it? The EEG has the same problem. The abnormal activity may not be going on when it is recording. So if youre really tired, you're more likely to have some abnormal electrical activity. One of the problems in detecting a seizure with an EEG is that the brain may be behaving itself while the recording is going on. An EEG is really a device that only tells us something if the brain is being abnormal during the test. A normal EEG does not eliminate the possibility of a seizure disorder. Another annoying part of the EEG is the glue used to attach wires to the head during the test. In order to get a good contact between the wire and your head, they use a glue that holds the wire in place. Many complain that the EEG glue takes a couple of days to wash out of their hair.
What do you do if suspect you have a seizure disorder? Approximately one million people in America have some form of seizure disorder. That's a large number of people. Doctors may prescribe anti-seizure medications. How do they work? Let's try to use another image or picture of how these chemicals work. Have you ever seen an oil lamp work? It has a wick and a knob that controls the wick. If you turn the wick way up, it burns more oil and the light gets brighter. What if I turn the wick down a little bit? I'm still getting light, but I'm not getting as much light. To some degree, anti-seizure medications work on the same principle. They calm the brain down. Seizures tend to happen when there is a lot of activity in the brain. Calming the brain down a little bit decreases the odds of having a seizure. That sounds great, so why isn't everyone with a head injury on anti-seizure medications? Remember when we turned down the flame in the lamp example? Other brain activities are also "turned down." Some seizure medications tend to produce fatigue in people. In general, all seizure medications have an influence on your thinking to one degree or another.
In the early days of head injury treatment, neurologists were typically giving nearly all head-injured people anti-seizure medications. We know that 5% of head-injured people have a seizure; if I give anti-seizure medications to everybody, I'm going to control those seizures, right? What's the problem? The majority of people don't need the medication and they have side effects. If you have a seizure in the hospital, you can pretty well bet you're going to be on anti-seizure medications for a while. But if you've never had a seizure while you were in the hospital following your head injury, it's unlikely that you will start off with that medication.
By Dr. Glen Johnson, Clinical Neuropsychologist
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