Epilepsy involves recurring seizures and the different types of epilepsy are usually distinguished by the type of seizure and area of the brain affected. Seizures are usually classified as being either partial seizures (also called local or focal seizures) or generalized seizures.

Partial seizures involve isolated areas of the brain. During a partial seizure, a person may or may not lose consciousness. They may experience abnormal sensations such as inexplicable feelings of joy, anger or sadness, or they may enter a dream-like state of semi-consciousness. These seizures are often marked by auras, which is a vague sensation that may indicate the beginning of a larger seizure.

Generalized seizures involve both sides of the brain simultaneously. These seizures are often more severe and may result in loss of consciousness, involuntary muscle contractions or abnormal body movements.

The types of epilepsy include:

• Temporal lobe epilepsy (TLE). Epilepsy marked by partial seizures in one or both of the temporal lobes in the brain. TLE is one of the most common types of epilepsy. It is thought that repeated seizures involving the temporal lobes may result in mild brain damage.
  
  
• Absence epilepsy. Epilepsy marked by absence seizures (also called petit mal seizures). During an absence seizure, people may experience a temporary lapse in consciousness. They may stare into space or make small unconscious movements, such as jerking their leg or blinking. Absence epilepsy is more common in children, although it often clears up as a child matures.
  
  
• Neocortical epilepsy. Epilepsy marked by partial or generalized seizures in the outer layer of the brain, called the cortex. People with neocortical epilepsy may experience visual hallucinations, emotional or behavioral changes, involuntary muscle contractions or loss of consciousness.
  
  
• Lennox-Gastaut syndrome. Disorder that includes severe epilepsy in children, experienced as a variety of generalized seizures. It usually appears within the first four years of life. Lennox-Gastaut syndrome is associated with mental retardation and may involve various forms of brain damage. Unlike other forms of epilepsy in children, Lennox-Gastaut syndrome rarely resolves itself naturally and there is no cure for the disorder.
  
  
• West syndrome. Epileptic condition that usually occurs within the first year of life, typically between the ages of 3 to 6 months old. This syndrome involves infantile spasms along with developmental impairment. Seizures may appear as a sudden bending forward and stiffening of the body and occur upon awakening. Seizures may resolve with or without treatment by mid-childhood. Infants with West syndrome may also develop Lennox-Gastaut syndrome as they get older.
  
  
• Ohtahara syndrome (also known as early infantile epileptic encephalopathy). An extremely rare epileptic condition that affects newborns with underdeveloped cerebral hemispheres. Seizures usually appear within the first 10 days of life. Ohtahara syndrome primarily involves a stiffening of the limbs with asymmetrical movements. Boys appear to be affected more often than girls. As the condition progresses, seizures become more frequent and are accompanied by physical and mental retardation. About half of all patients with this condition die in infancy. Surviving infants may go on to develop West syndrome and Lennox-Gastaut syndrome as they grow older.