Electroencephalogram, Defined

We've made quite a few references to EEGs over the past few months, with the results of these tests being the primary method of seeing neurological improvements. However, we also realized that most folks don't have any idea what an EEG is. So with our last appointment at the Neurophysiology clinic, we decided we'd take some pictures so everyone can see what the little lady has to go through.

First though, here's what WebMd has to say about Electroenchepalograms:

"An electroencephalogram (EEG) is a test that measures and records the electrical activity of your brain. Special sensors (electrodes) are attached to your head and hooked by wires to a computer. The computer records your brain's electrical activity on the screen or on paper as wavy lines. Certain conditions, such as seizures, can be seen by the changes in the normal pattern of the brain's electrical activity."

Here's what goes on when we have an appointment for an EEG:

We typically show up about fifteen minutes prior to the scheduled start to get checked in. Then our technician comes and gets us from the waiting room and she works on getting Kylie all hooked up, which is a fairly involved process that probably takes twenty to thirty minutes. First she marks up Kylie's head with a red grease pencil to determine where each of the twenty-six electrodes will be placed.

The electrodes are hooked up to a computer which reads the brain activity. Without getting too scientific, a normal EEG looks something like this. That is, if this picture from Mass General is correct. I don't know, I'm not a neurologist!

Below is what an abnormal EEG looks like when hypsarrhythmia (chaotic brain wave activity) is present. This is the most commonly found EEG pattern associated with Infantile Spasms.

There is also a camera hooked up so that any physical seizure symptoms can be noted.

The technician then places each electrode on Kylie's head with some glue that helps keep everything in place - it really stinks too! Then she injects some goop into each electrode, which helps transmit the electrical activity. After all that, Kylie gets wrapped up in guaze to help keep everything secure.

Remember that prior to each EEG we have to sleep deprive her for about five hours so that she'll fall asleep during the test itself. As you can guess, Mom and Dad also get sleep deprived! The sleep deprivation has to do with getting a more accurate reading during sleep. Needless to say it's usually (but not always) tough to keep her awake before the test starts. As you can see by the picture, she's pretty pooped as she's getting ready for everything to get going!

So during the test (if everything goes according to plan) she sleeps for at least ten minutes, and usually no more than twenty or so. Then we wake her up and flash the "party lights" in her face. This is a strobe light where the flashes get faster and faster until the flashes just about turn into a solid light. This is to see if she is photosensitive - obviously if she is, then these lights can induce a seizure.

After that, it's time to get up and get all those yucky electrodes off. Here she is after waking:

What a cutie! She's such a little trooper.

After all that, the Neurophysiology clinic sends the readout up to the Neurologist. Within a couple days after that we usually get the results ourselves.