Seizures are classified in two main categories:
Partial seizures -- involve a part of the brain. They can be:
Simple partial seizures -- Symptoms may include involuntary twitching of the muscles or arms and legs; changes in vision; vertigo; and experiencing unusual tastes or smells. The person does not lose consciousness.
Complex partial seizures -- Symptoms may be similar to those of partial seizures, but the person does lose awareness for a time. The persona may engage in repetitive behavior (like walking in a circle or rubbing their hands) or stare.
Generalized seizures -- involve much more or all of the brain. They can be:
Absence seizures (petit mal) -- Symptoms may include staring and brief loss of consciousness.
Myoclonic seizures -- Symptoms may include jerking or twitching of the limbs on both sides of the body.
Tonic-clonic seizures (grand mal) -- Symptoms may include loss of consciousness, shaking or jerking of the body, and loss of bladder control. The person may have an aura or an unusual feeling before the seizure starts. These seizures can last from 5 - 20 minutes.
The severity of symptoms can vary greatly, from simple staring spells to loss of consciousness and violent convulsions. For most people with epilepsy, each seizure is similar to previous ones. The type of seizure a person has depends on a variety of things, such as the part of the brain affected and the underlying cause of the seizure.
An aura consisting of a strange sensation (such as tingling, smelling an odor that isn't actually there, or emotional changes) occurs in some people prior to each seizure.