Types of Seizures

According to the most recent (2017) International League Against Epilepsy (ILAE) seizure classification, seizures are classified as having a focal onset or a generalized onset. Focal onset seizures arise from a restricted area of the brain. These are due to abnormal electrical activity in a particular group of cells in the brain. They are classified according to the level of awareness. Focal seizures with impaired awareness occur with alteration or complete loss of awareness. Performing repetitive movements, like chewing or fiddling , and not responding to stimuli in the environment are common.
  • Focal aware seizures occur when awareness is not lost, though it is not without other symptoms. Distinctive signs can include a change of emotions, involuntary movement of a particular body part, dizziness, and altered senses, such as taste and smells.
  • Generalized onset seizures arise from both sides of the brain at the same time. Clinically, there are a variety of types.
  • Absence seizures, commonly known as “petit mal seizures”, typically occur in children. Symptoms include blank staring into space and slight body movement, like blinking. These seizures may happen in succession of each other and cause a momentary loss of awareness.
  • Tonic seizures cause a stiffening of the muscles. The most commonly affected body parts are the back, arms, and legs.
  • Atonic seizures can result in a loss of muscle control, likely causing the patient to fall down.
  • Clonic seizures affect the neck, face, and arms and are known for resulting recurrent or rhythmic muscle movements.
  • Myoclonic seizures are known for causing jerks of the extremities.
  • Tonic-clonic seizures, commonly known as “grand mal” seizures, are the most intense type of epileptic seizure. Symptoms can include immediate loss of consciousness, accidental urination, stiffening of the body or tongue biting.