Epilepsy

What is epilepsy?

Epilepsy is a disorder of the brain characterized by repeated seizures. A seizure is usually defined as a sudden alteration of behavior due to a temporary change in the electrical functioning of the brain. Normally, the brain continuously generates tiny electrical impulses in an orderly pattern. These impulses travel along neurons — the network of nerve cells in the brain — and throughout the whole body via chemical messengers called neurotransmitters.

Epilepsy is usually diagnosed after a person has had at least two seizures that were not caused by some known medical condition, such as alcohol withdrawal or extremely low blood sugar.

If seizures arise from a specific area of the brain, then the initial symptoms of the seizure often reflect the functions of that area. The right half of the brain controls the left side of the body, and the left half of the brain controls the right side of the body. For example, if a seizure starts from the right side of the brain in the area that controls movement in the thumb, then the seizure may begin with jerking of the left thumb or hand.

Seizures vary so much that epilepsy specialists frequently re-classify seizure types. Typically, seizures belong in one of two basic categories: primary generalized seizures and partial seizures. The difference between these types is in how they begin. Primary generalized seizures begin with a widespread electrical discharge that involves both sides of the brain at once. Partial seizures begin with an electrical discharge in one limited area of the brain.

Epilepsy in which the seizures begin from both sides of the brain at the same time is called primary generalized epilepsy. Hereditary factors are important in partial generalized epilepsy, which is more likely to involve genetic factors than partial epilepsy — a condition in which the seizures arise from a limited area of the brain.

Some partial seizures are related to head injury, brain infection, stroke or tumor but, in most cases, the cause is unknown. One question that is used to further classify partial seizures is whether consciousness (the ability to respond and remember) is impaired or preserved. The difference may seem obvious, but there are many degrees of consciousness impairment or preservation.

The following factors may increase the risk of seizures in people predisposed to seizures:

• Stress
• Sleep deprivation or fatigue
• Insufficient food intake
• Alcohol use or drug abuse
• Failure to take prescribed anticonvulsant medications

About half of the people who have one seizure without a clear cause will have another one, usually within six months. A person is twice as likely to have another seizure if there is a known brain injury or other type of brain abnormality. If the patients does have two seizures, there is about an 80 percent chance of having more. If the first seizure occurred at the time of an injury or infection in the brain, it is more likely the patient will develop epilepsy than if the seizure did not happen at the time of injury or infection.

Symptoms

Because epilepsy is caused by abnormal activity in the brain, seizures can affect any process your brain coordinates. Seizure signs and symptoms may include:

• Temporary confusion
• A staring spell
• Uncontrollable jerking movements of the arms and legs
• Loss of consciousness or awareness
• Psychic symptoms such as fear, anxiety or deja vu

Symptoms vary depending on the type of seizure. In most cases, a person with epilepsy will tend to have the same type of seizure each time, so the symptoms will be similar from episode to episode.

Doctors generally classify seizures as either focal or generalized, based on how the abnormal brain activity begins.

Focal seizures

When seizures appear to result from abnormal activity in just one area of your brain, they’re called focal (partial) seizures. These seizures fall into two categories:

• Focal seizures without loss of consciousness. Once called simple partial seizures, these seizures don’t cause a loss of consciousness. They may alter emotions or change the way things look, smell, feel, taste or sound. They may also result in involuntary jerking of a body part, such as an arm or leg, and spontaneous sensory symptoms such as tingling, dizziness and flashing lights.
• Focal seizures with impaired awareness. Once called complex partial seizures, these seizures involve a change or loss of consciousness or awareness. During a complex partial seizure, you may stare into space and not respond normally to your environment or perform repetitive movements, such as hand rubbing, chewing, swallowing or walking in circles.

Symptoms of focal seizures may be confused with other neurological disorders, such as migraine, narcolepsy or mental illness. A thorough examination and testing are needed to distinguish epilepsy from other disorders.

Generalized seizures

Seizures that appear to involve all areas of the brain are called generalized seizures. Six types of generalized seizures exist.

• Absence seizures. Absence seizures, previously known as petit mal seizures, often occur in children and are characterized by staring into space or subtle body movements such as eye blinking or lip smacking. These seizures may occur in clusters and cause a brief loss of awareness.
• Tonic seizures. Tonic seizures cause stiffening of your muscles. These seizures usually affect muscles in your back, arms and legs and may cause you to fall to the ground.
• Atonic seizures. Atonic seizures, also known as drop seizures, cause a loss of muscle control, which may cause you to suddenly collapse or fall down.
• Clonic seizures. Clonic seizures are associated with repeated or rhythmic, jerking muscle movements. These seizures usually affect the neck, face and arms.
• Myoclonic seizures. Myoclonic seizures usually appear as sudden brief jerks or twitches of your arms and legs.
• Tonic-clonic seizures. Tonic-clonic seizures, previously known as grand mal seizures, are the most dramatic type of epileptic seizure and can cause an abrupt loss of consciousness, body stiffening and shaking, and sometimes loss of bladder control or biting your tongue.

Causes

Epilepsy has no identifiable cause in about half the people with the condition. In the other half, the condition may be traced to various factors, including:

• Genetic influence. Some types of epilepsy, which are categorized by the type of seizure you experience or the part of the brain that is affected, run in families. In these cases, it’s likely that there’s a genetic influence.

  Researchers have linked some types of epilepsy to specific genes, but for most people, genes are only part of the cause of epilepsy. Certain genes may make a person more sensitive to environmental conditions that trigger seizures.

• Head trauma. Head trauma as a result of a car accident or other traumatic injury can cause epilepsy.
• Brain conditions. Brain conditions that cause damage to the brain, such as brain tumors or strokes, can cause epilepsy. Stroke is a leading cause of epilepsy in adults older than age 35.
• Infectious diseases. Infectious diseases, such as meningitis, AIDS and viral encephalitis, can cause epilepsy.
• Prenatal injury. Before birth, babies are sensitive to brain damage that could be caused by several factors, such as an infection in the mother, poor nutrition or oxygen deficiencies. This brain damage can result in epilepsy or cerebral palsy.
• Developmental disorders. Epilepsy can sometimes be associated with developmental disorders, such as autism and neurofibromatosis.

A doctor makes his or her epilepsy diagnosis based on symptoms, physical signs and the results of such tests as an electroencephalogram (EEG), computed tomography (CT or CAT scan) or magnetic resonance imaging (MRI).

It is essential that the type of epilepsy and the type of seizures both are diagnosed properly. There are several major classifications of seizures and most are associated with specific forms of the disorder.

Risk factors

Certain factors may increase your risk of epilepsy:

• Age. The onset of epilepsy is most common in children and older adults, but the condition can occur at any age.
• Family history. If you have a family history of epilepsy, you may be at an increased risk of developing a seizure disorder.
• Head injuries. Head injuries are responsible for some cases of epilepsy. You can reduce your risk by wearing a seat belt while riding in a car and by wearing a helmet while bicycling, skiing, riding a motorcycle or engaging in other activities with a high risk of head injury.
• Stroke and other vascular diseases. Stroke and other blood vessel (vascular) diseases can lead to brain damage that may trigger epilepsy. You can take a number of steps to reduce your risk of these diseases, including limiting your intake of alcohol and avoiding cigarettes, eating a healthy diet, and exercising regularly.
• Dementia. Dementia can increase the risk of epilepsy in older adults.
• Brain infections. Infections such as meningitis, which causes inflammation in your brain or spinal cord, can increase your risk.
• Seizures in childhood. High fevers in childhood can sometimes be associated with seizures. Children who have seizures due to high fevers generally won’t develop epilepsy. The risk of epilepsy increases if a child has a long seizure, another nervous system condition or a family history of epilepsy.

Complications

Having a seizure at certain times can lead to circumstances that are dangerous to yourself or others.

• Falling. If you fall during a seizure, you can injure your head or break a bone.
• Drowning. If you have epilepsy, you’re 15 to 19 times more likely to drown while swimming or bathing than the rest of the population because of the possibility of having a seizure while in the water.
• Car accidents. A seizure that causes either loss of awareness or control can be dangerous if you’re driving a car or operating other equipment.

  Many states have driver’s license restrictions related to a driver’s ability to control seizures and impose a minimum amount of time that a driver be seizure-free, ranging from months to years, before being allowed to drive.

• Pregnancy complications. Seizures during pregnancy pose dangers to both mother and baby, and certain anti-epileptic medications increase the risk of birth defects. If you have epilepsy and you’re considering becoming pregnant, talk to your doctor as you plan your pregnancy.

  Most women with epilepsy can become pregnant and have healthy babies. You’ll need to be carefully monitored throughout pregnancy, and medications may need to be adjusted. It’s very important that you work with your doctor to plan your pregnancy.

• Emotional health issues. People with epilepsy are more likely to have psychological problems, especially depression, anxiety and suicidal thoughts and behaviors. Problems may be a result of difficulties dealing with the condition itself as well as medication side effects.

Other life-threatening complications of epilepsy are uncommon, but may happen, such as:

• Status epilepticus. This condition occurs if you’re in a state of continuous seizure activity lasting more than five minutes or if you have frequent recurrent seizures without regaining full consciousness in between them. People with status epilepticus have an increased risk of permanent brain damage and death.
• Sudden unexpected death in epilepsy (SUDEP). People with epilepsy also have a small risk of sudden unexpected death. The cause is unknown, but some research shows it may occur due to heart or respiratory conditions.

  People with frequent tonic-clonic seizures or people whose seizures aren’t controlled by medications may be at higher risk of SUDEP. Overall, about 1 percent of people with epilepsy die of SUDEP.

Epilepsy treatments

There is currently no cure for most types of epilepsy. However, surgery can stop some kinds of seizure from occurring, and in many cases, the condition can be managed.

If an underlying correctable brain condition is causing the seizures, sometimes surgery can stop them. If epilepsy is diagnosed, the doctor will prescribe seizure-preventing drugs or anti-epileptic drugs.

If drugs do not work, the next option could be surgery, a special diet or VNS (vagus nerve stimulation).

The doctor’s aim is to prevent further seizures from occurring, while at the same time avoiding side effects so that the patient can lead a normal, active, and productive life.

Anti-epileptic drugs (AEDs)

The majority of AEDs are taken orally. The type of seizure the patient is having will decide which drug the doctor may prescribe. Patients do not all react in the same way to drugs, but AEDs appear to help control seizures in 70 percent of cases.

Drugs commonly used to treat epilepsy include:

• sodium valproate
• carbamazepine
• lamotrigine
• levetiracetam

Some drugs may stop seizures in one patient, but not in another. Even when the right drug is found, it can take some time to find the ideal dose.

Outlook

Epilepsy can affect a person’s life in multiple ways, and the outlook will depend on various factors.

Will seizures continue?

If the cause is clearly identifiable, seizures are more likely to continue.

Other factors affecting the chances of remission include:

• access to treatment
• response to treatment
• age when symptoms started
• other neurological condition the person may have

Can epilepsy lead to brain damage?

A study published in 2005 suggested that people with severe epilepsy who continue to experience seizures were more likelyTrusted Source to have difficulties with cognitive ability and brain function. Longer periods of remission were linked with fewer cognitive problems.

A review published in 2006 concluded that there may be a “mild but measurable” decline in some people in intellectual performance” of adults and children.

However, the researchers point out that there is little reliable research in this area, and that “Due to many confounding variables, the effect of seizures per se is difficult to estimate, but appears limited.”

If there is a risk, say the authors, it appears to be higher among those with generalized symptomatic types of epilepsy, with frequent seizures that started at an early age, and a high level of antiepileptic drug use.

Recent studies have looked at cognitive changes in children as they age, either with or without epilepsy. ResultsTrusted Source suggest that epilepsy is associated with worse cognitive outcomes.

However, it is unclear whether:

• epilepsy causes the impairment
• a similar structural change causes both the epilepsy and the impairment
• antiepileptic drugs have an effect

This is an area that needs further research

Other effects

Epilepsy can affect various aspects of a person’s life, including:

• emotions and behavior
• social development and interaction
• ability to study and work

The impact on these areas of life will depend largely on the frequency and severity of seizures.

Life expectancy of people with epilepsy

In 2013, researchers from the University of Oxford and University College London in the U.K. reported that people with epilepsy are 11 times more likely to experience premature death, compared with the rest of the population.

The risk appears to be greater if the person also has a mental illness. Suicides, accidents, and assaults accounted for 15.8 percent of early deaths. Most people affected by these had also been diagnosed with a mental disorder.