Seizure:

Watch this 2-Minute Neuroscience video to learn about epilepsy, a disorder characterized by recurrent seizures.

an event that is associated with uncontrolled and excessive brain activity, leading to a variety of symptoms. The exact symptoms depend on the type of seizure and where in the brain it originates, but may involve convulsions, excessive muscle contraction, loss of muscle tone, and/or loss of consciousness.