A brain is made up of nerves call neurons which control everything we do. In a healthy brain, electrical and chemical signals are fired between neurons – this interaction drives the brain’s ability to think, feel and send instructions to parts of the body.
When the electrical system in the brain malfunctions, abnormal electrical activity (if the electrical signals are disrupted or there are too many electrical messages at once) can overwhelm the neurons and cause a string of abnormal and uncontrolled signalling. This is called a seizure.
For a seizure to occur, there must be a wave of abnormal and uncontrolled signalling through many neurons. The abnormal electrical signal would be sent through a community of neurons – neurons connected to many other neurons within a few synapses – and the electrical signal must be strong enough to influence other neurons to pass on the abnormal signal.
This causes the electrical signal to pass between neurons very quickly, disrupting normal brain activity. When seizures occur on a regular basis, we call it epilepsy.