Epilepsy is a common neurological disorder affecting children, adults and older adults. The condition involves recurrent seizures following hyper-excitability of brain cells (i.e., neurons). Just because someone has one seizure does not mean that they have epilepsy. A diagnosis of epilepsy generally requires that one have two unprovoked seizures – meaning not due to some other known cause (e.g., drug intoxication, acute stroke, non-epileptic seizures) - at least 24-hours apart or one unprovoked seizure with a greater than 60% chance of having enduring seizures, per a physician’s expert determination.
Epilepsy affects nearly 2.2 million people in the U.S. and approximately 150,000 new cases are diagnosed each year. By 20 years of age, 1 out of every 100 people will develop epilepsy, whereas 3 out of every 100 individuals will be diagnosed by age 80. Across North America, epilepsy is more common in racial and ethnic minorities, as well as individuals from impoverished backgrounds.
Types of Seizures
During a seizure, the affected regions of the brain are unable to perform the kinds of functions that they normally do. This can result in sudden alterations of movement, sensation, awareness, or other kinds of purposeful behavior. Seizures manifest in a variety of ways and typically last for a few seconds to a few minutes (seizures lasting longer than 10-minutes uninterrupted may be a medical emergency and should result in emergency department care). How seizures appear can be very helpful to locate their point of origin in the brain and to plan effective treatments.
Generalized Seizures are the result of hyperexcitability of the whole brain all at once, making it difficult to identify the cause.
- Tonic-clonic Seizures (formerly grand mal seizures) result in sudden increases and loss of muscle tone, leading patients to jerk uncontrollably. Awareness and the ability to respond are disrupted and the patient can take a while to return to their normal state after the seizure ends.
- Absence Seizures (formerly petit mal) begin suddenly and occur without warning. Symptoms include staring off into space for a short while (~15 seconds).
- Myoclonic Seizures (myo meaning “muscle”, clonic meaning “jerk”) result in an increase in muscle tone and typically react as if the person has had an electric shock.
- Atonic Seizures cause a person’s muscles to go completely limp and can lead to sudden falls (drop attacks), which can cause serious injury.
Partial Seizures are also known as focal seizures and refer to seizures beginning in one area of the brain only, although their effects can travel to other brain regions too or from one cerebral hemisphere to the other (i.e., secondary generalization).
- Simple Partial Seizures start in one area on one side of the brain, but may spread to other parts. During the seizure, a person may have uncontrollable movements or strange sensations. A person remains aware during the simple partial seizure and can communicate normally.
- Complex Partial Seizures also begin in one area of the brain, but affect areas that lead people to lose awareness of how their behaviors change during the seizure. People can sometimes have a warning (or an aura) before this type of seizure manifesting as a strange smell, indigestion or abnormal emotions (e.g., sudden anxiety); these warning signs can allow individuals to get to a safe place or alert others to the oncoming seizure.
Causes and Risk Factors
The cause of epileptic seizures may not be apparent in as many as 50-70% of cases. This can be frustrating to patients.
Common risk factors include:
- Developmental disabilities
- Autism spectrum disorder
- Abnormal blood vessels in the brain
- Brain injuries
- Brain tumors
- Brain infections
- Family history of epilepsy
- Seizures with high fevers
- Fever-related (febrile) seizures that are unusually long
- Drug abuse
Cognition in Epilepsy
Cognitive deficits are relatively common in people with epilepsy, and may correspond to disruptions of affected brain regions, side effects from antiepileptic drugs and/or a combination of these factors.
Among those with partial seizure disorders, seizures start in the temporal lobes in 50-80% of cases and may lead to problems with learning and memory (this is especially the case when seizures have led to scar tissue emerging deep within the temporal lobe (known as mesial temporal sclerosis); word-finding difficulty and other language impairments may also occur, as well as mood alterations (e.g., depression and anxiety). Individuals with frontal lobe seizures make up about 20-30% of focal cases and can have chronic problems with impulsivity, planning, organization and self-monitoring of behaviors/reactions, as well as acute issues with motor control. Occipital lobe seizures (6-8% of cases) and parietal lobe seizures (1-6% of cases) are much less common, but these disorders may cause deficits in sensation and perception.
Psychological and Social Issues in Epilepsy
Though seizures last only seconds to minutes, psychosocial difficulties can be quite pervasive. Even one seizure per year can result in driving limitations (see your state’s laws on driving with seizures), work restrictions, and stigma/discrimination. Furthermore, the point at which one achieves seizure freedom may follow a lengthier period of symptomatic epilepsy that already interfered with social, educational and vocational development, thereby leading to more long lasting psychosocial consequences.
Unemployment, under-employment, and educational disparities are evident in people with epilepsy compared to otherwise healthy peers. Reduced rates of marriage and childbirth have been noted for both men and women. Daily psychosocial difficulties, may include poor self-esteem and reduced self-efficacy, as well as increased rates of depression, anxiety and suicidality.
Medication: Pharmacotherapy with anticonvulsants (or antiepileptic drugs) is the first line of defense against seizures; however, approximately 30% of individuals will not achieve seizure freedom with drug therapy alone.
Surgery: Various surgical interventions are available at Level IV Comprehensive Epilepsy Centers, and are most indicated for people with intractable partial (focal) epilepsy. Surgeries recommended may include laser- or thermal (heat) ablation treatments, focal resections of lesions causing seizures, as well as hemispherectomy (removal of an entire brain hemisphere implicated in seizure onset, or corpus colostomy (which would separate the do hemispheres of the brain, inhibiting the spread of seizures from one hemisphere to the other).
Vagus Nerve Stimulation: This intervention is usually indicated in individuals for whom surgery is not an option; it involves inserting a small pacemaker-like device into one’s chest to inhibit over-excitation of brain cells, thereby diminishing the likelihood of a seizure.
Diet Therapy: There are several diets that may help to reduce seizure frequency, the oldest of which is the ketogenic diet. This consists of consuming foods high in fat and severely limiting carbohydrates. Ketogenic and similar diet therapies should be discussed with and managed by a competent and knowledgeable physician before incorporating it into one’s self-management plan.
Psychotherapy: Cognitive-behavioral treatments to learn techniques for managing the stress, symptoms and psychosocial consequences of seizures can aid in maintaining independence and quality of life.