Brain cells, or neurons, communicate with each other by a combination of electric and chemical signals. These signals travel along a large network of cells in a highly coordinated fashion. During a seizure, the cells temporarily lose the ability to act as individual units. A large number of neighbouring cells discharge signals all at once in a rhythmic pattern. This excessive activity overwhelms normal function in the area in which it occurs. This results in uncontrollable changes to movement, sensation, behaviour, level of consciousness and/or breathing. These are seizures. Most seizures last less than five minutes and the brain returns to normal functioning.
Seizures take make many forms, but doctors classify them into two main categories that help determine the best course of treatment:
A focal seizure involves an abnormal discharge in a smaller part of one side of the brain. The person either remains fully conscious or consciousness may be impaired. There are two types focal seizures – focal and focal dyscognitive. Learn more by visiting our Focal Seizures page
In a generalized seizure both sides of brain are involved. The person usually loses consciousness. The two most common types of generalized seizures are absence and tonic-clonic seizures. Learn more by visiting our Generalized Seizures page