A seizure is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with loss of consciousness to shaking movements involving only part of the body with variable levels of consciousness to a subtle momentary loss of awareness. Most of the time these episodes last less than 2 minutes and it takes some time to return to normal. Loss of bladder control may occur.