NEW YORK PUBLIC LIBRARY / SCIENCE PHOTO LIBRARY NEW YORK PUBLIC LIBRARY / SCIENCE PHOTO LIBRARY
The seizures of epilepsy are dramatically demonstrated by the EEG traces. The largest and most regular electrical activity of the brain occurs in an attack of 'petit mal', although the patient may only go blank for a few seconds. The ' wave and spike' fluctuations (top), explosions of electrical energy, may involve almost the whole brain for a minute or more. During the more dangerous and more terrifying 'grand mal', in which the patient falls to the ground, loses conscious-ness, goes stiff and then jerks violently, the traces show modest 8-per second waves which then increase in frequency and fluctuation (center) until, at the jerking stage, the pattern changes to show complex discharges, rather like the 'wave and spike' of petit mal, one discharge for.
Model release not required. Property release not available.