Brain and brain waves in epilepsy
Caption: 3D magnetic resonance imaging (MRI) scan of a brain (seen from the front), overlaid with an electroencephalogram (EEG) of a 17-year-old’s brain during an epileptic episode (chaotic brain activity). This EEG shows generalized epilepsy, where the whole brain cortex is affected: all the EEG traces show chaotic brain waves. Epilepsy can have many causes, but when the cause is unknown, as here, it is called essential epilepsy. An EEG measures the electrical activity of the brain using electrodes attached to the scalp. The electrode locations are labelled at far left, on diagrams of the head seen from above, with the front of the head at left.
