New systems for a two-speed electroencephalograph with an auditory device for diminishing the length of seizures

The author describes a system for testing patients with petit mal seizures. The system has the following advantages: 1) EEG paper speed is automatically increased from 2.5 mm/s to 25 mm/s when brainwave activity increases, with the increased speed maintainable for up to 4.0 sec after the last seizure burst. Control studies with constant speed and two-speed systems operating simultaneously demonstrate that no significant distortion occurs at the moment of change in speed. The convenience of handling a greatly reduced volume of paper is obvious. 2) An auditory stimulus, either a pure tone burst of 1000 HZ or loud music, is also triggered by an increase in amplitude of brainwave activity. Testing of 15 patients shows a significant decrease (p less than 0.01) in duration of seizure activity when the stimulus is activated.