The . The most common type of eeg, or electroencephalogram, uses recording surfaces placed on the scalp (and a few elsewhere on the head) to record the electrical activity of the surface of the brain, the cerebral cortex. This electrical activity, sometimes referred to as "brain waves, " can be broken down into frequency bands called delta, theta, Alpha and beta. Delta is the slowest range and beta is the fastest. Some medications can have a noticeable effect on this activity, but modest to moderate doses of opioids (like vicodin and morphine), have little effect. Higher doses usually result in slower frequency bands showing up, usually spread over the entire recorded surface of the brain, but sometimes appearing to come from restricted brain regions. These patterns are well-recognized by neurologists who interpret eegs, a process that requires a high degree of training and experience.
Many changes. There are epiliptiform changes in eeg that can be seen with a variety of opioids, with some causing more changes than others. Hydrocodone (vicodin) is converted to morphine and one of its metabolites can cause mental status changes. Other opioids. Like demerol, (meperidine hydrochloride) talwin and Darvon actually can cause seizures, and produce changes in eeg.