Epilepsy
What is epilepsy?
Epilepsy is a common neurological disorder in which the normal activity of brain cells is sometimes disturbed, resulting in a seizure. Seizures can cause muscle spasms or loss of consciousness and may be associated with strange sensations, emotions and changed behaviour.
Seizures vary greatly, from a brief lapse in attention or muscle jerk to severe and prolonged convulsions. Seizures can also vary in frequency, from less than one a year to several per day.
There are two main categories of seizure:
- Focal seizures start in just one part of the brain
- Generalized seizures are the result of simultaneous abnormal activity in the whole of the brain
There are many different types of epilepsy, and doctors have identified more than 100 different epilepsy syndromes. Each is characterized by specific signs and symptoms. Specific classification and delineation of the underlying cause are important, as they guide treatment and determine prognosis.
How common is epilepsy?
Epilepsy is the most common serious brain disorder worldwide with over 50 million people with the condition; it is especially prevalent in childhood, adolescence and old age. In Canada, approximately 300,000 people live with epilepsy.
What causes epilepsy?
Many things can cause epilepsy, though it is not always clear. In fact, around half of epilepsy cases are idiopathic, meaning the cause is unknown. There are five general categories of epilepsy causes:
- Infection: A number of different brain infections can cause epilepsy
- Structural causes: Abnormal structures in the brain can cause epilepsy and may be present at birth or acquired through an injury, brain tumor, stroke or other cause
- Genetic causes: Epilepsy can be caused by genetic defects, which can be inherited or occur spontaneously
- Autoimmune epilepsy: Immune system reactions, such as antibodies targeting the brain, can cause epilepsy
- Metabolic causes: Problems with the enzymes that break down food in the body can result in epilepsy
There is no known cure for the different types of epilepsy, but through treatment, many people are able to control their seizures.
For most people, the first step in treatment is medication. Healthcare providers typically begin by prescribing a single antiseizure medication (ASM). Overall, up to 70% of patients become seizure free after the start of treatment with ASMs. If seizures are not controlled with a single ASM, healthcare providers may prescribe additional ASMs. Healthcare providers determine which ASM to prescribe based on multiple factors, including the type of seizure, the frequency of seizures and the patient's lifestyle.
For some patients, healthcare providers may consider non-pharmacological treatments, such as special diets and devices that send small electrical signals to the nervous system to change how neurons behave. Surgery may also be considered for patients with drug-resistant seizures.