The definition of epilepsy has been updated by the International League Against Epilepsy.
The definition of epilepsy has recently changed to help physicians and healthcare professionals treating patients with suspected epilepsy to improve the timeliness of diagnostic and treatment options.
Speaker Jacqueline French, MD, discussed the new definition of epilepsy at the Annual Fundamentals Symposium: The New Definition and Classification of Epilepsy at the American Epilepsy Society conference on Friday, December 2, 2016.
Before the revision, the guideline was for physicians to wait until 2 spontaneous seizures occurred before treating a patient with suspected epilepsy. However, this raises questions such as “Is it necessary or appropriate to put off treatment until 2 seizures have been experienced?” and “If it is known that epilepsy has developed, should physicians still wait to initiate treatment?”
The revised definition removes any burden on physicians to determine the risk of a second seizure for each patient. Physicians are now trying to diagnose epilepsy after the first seizure, as long as the necessary evidence is present, Dr French said.
In the article “A Practical Clinical Definition of Epilepsy,” which updated the definition of the disease, epilepsy is considered to be present if there are 2 unprovoked seizures within 24 hours or if the probability of additional seizures after the first is similar to the general recurrence risk of 60%.
In addition, the new definition says that if there is enough information to diagnose an epilepsy syndrome without the presence of seizures, a patient can be given a diagnosis of epilepsy. For example, Dr French said that a diagnosis can be made if a patient had a single seizure plus an electroencephalogram (EEG) that shows centrotemporal spikes.
Although the definition has changed and may speed up diagnosis, treatment may not be an immediate decision, according to the session. Time to treatment varies depending on the uncertainty present after 1 seizure because there is no concrete diagnostic test for determining the risk of another seizure.
Dr French also discussed the American Academy of Neurology’s guideline called Management of an Unprovoked First Seizure of Adults, which aligns with the updated definition of epilepsy. This evidence-based review allows physicians to review certain factors prior to treating a patient who may have epilepsy.
According to the American Academy of Neurology review, patients who experienced an unprovoked first seizure should be informed that recurrence is most likely to occur within 2 years. Other factors that increase the risk for seizure recurrence include a prior seizure, an epileptiform EEG, an abnormal computed tomography scan or magnetic resonance image, and a nocturnal seizure, according to the session.
The presence of these additional factors may impact a physician’s decision to treat.
The guideline also states that immediate treatment with antiepileptic drugs may help to reduce the occurrence of a second seizure within 2 years. By treating patients more rapidly, they are less likely to experience poor health outcomes and healthcare costs associated with seizures.
However, the final decision about whether to initiate treatment should be based on a physician’s assessment of the risks of adverse events from antiepileptic drugs, the potential risk of seizure recurrence, and input from the patient.
Dr French concluded that the new definition of epilepsy will better align with treatment strategies implemented by physicians, as well as allow them to have more involved conversations with their patients. Perhaps in the future, these guidelines could also help create an additional marker for the disease.