Epilepsy is a disorder of the brain that causes recurrent seizures.
A seizure is an abnormal burst of electrical discharges that disrupts the normal electrical function of the brain.
Symptoms and signs of epilepsy depend on the areas of the brain activated by the abnormal electrical activity. If the entire brain or a large part of the brain is involved from the beginning of the seizure (generalized epilepsy), many people experience a loss of awareness without any warning. This is typically associated with stiffening and shaking of the whole body.
If the seizure starts from a small area of the brain (focal epilepsy), a person may experience a warning, known as an aura. The aura is caused by seizure activity affecting a specific part of the brain. An aura can be helpful in identifying the region of the brain first affected by the abnormal electrical activity. Symptoms of an aura may include numbness or tingling; unusual smells, sounds, or visual distortions; feelings of nausea; fear; déjà vu; or involuntary movements. Seizures that begin from a small area of the brain may spread to involve larger regions and may progress to loss of awareness and whole-body stiffening and shaking.
Because seizures often start as large seizures or have a tendency to evolve into large seizures, people frequently lose awareness and are unable to recall the events during a seizure. Often, a person realizes that he or she has had a seizure only after it has ended and the consequences of the seizure—such as loss of time, confusion, or a tongue bite or other injury—are detected. For this reason, witness accounts of the seizure are often helpful in determining the type and frequency of seizures.
There are many causes of epilepsy, although in about half of cases, no clear underlying cause is found. The age at which epilepsy starts can be helpful in identifying the underlying cause. The illustration lists common causes by age group.
The goals of an epilepsy evaluation include determining the type of seizures and the part of the brain that is affected. This determination is made by a detailed account of the seizures, a thorough neurological examination, and the following common tests:
Electroencephalogram (EEG) measures the brain’s electrical activity to show characteristic findings of underlying seizures and help pinpoint their location.
Brain imaging includes computed tomography (CT) or magnetic resonance imaging (MRI). These tests look for structural abnormalities within the brain that may lead to seizures.
Choice of medication is based on type of seizures, medication side effects, patient and physician preferences, and drug interactions. Approximately half of all patients with epilepsy will become seizure free after trying their first medication. Additional medications may be tried if the seizures continue. In certain cases in which medications are not effective, additional options may be tried, including nervous system stimulation or brain surgery.
National Institute of Neurological Disorders and Strokewww.ninds.nih.gov/disorders/epilepsy/epilepsy.htm
Conflict of Interest Disclosures: The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Gavvala reports a clinical research training fellowship from the American Academy of Neurology/American Brain Foundation. Dr Schuele reports speaker fees from Sunovion and Eisai and grants from the National Institute of Neurological Disorders and Stroke and Danny Did Foundation.
Source: Gavvala JR, Schuele SU. New-onset seizures in adults and adolescents: a review. JAMA. doi:10.1001/jama.2016.18625
Topic: Neurological Disorders
Gavvala JR, Schuele SU. Epilepsy. JAMA. 2016;316(24):2686. doi:10.1001/jama.2016.18623