How much tome to take eeg testing (electroencephalogram)?

30 minutes: It all depend the purpose of the eeg. A conventional eeg here at texas tech is 40 minutes; in many cases a series of eegs at different hours of the day and night are necessary for diagnosis. A sleep eeg for narcolepsy of sleep apnea runs all night; and prior to epilepsy surgery is 7-10 days and night.

20-40 minutes: Putting the electrodes in place initially takes 20-30 minutes, and then the test proper takes 20-40 minutes after that. Sometimes people will get an "ambulatory eeg, " in which the study goes on for days at a time, but these are much less common.