Epilepsy is a brain disorder in which clusters of neurons in the brain sometimes signal abnormally. Epilepsy may develop because of an abnormality in brain wiring, an imbalance of neurotransmitters, or some combination of these factors. During an epileptic seizure, neurons may fire as many as 500 times a second, much faster than the normal rate of about 80 times a second. When the normal pattern of neuronal activity becomes disturbed, strange sensations, emotions and behavior, convulsions, muscle spasms, and loss of consciousness may be experienced.