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Epilepsy

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What is epilepsy?

Epilepsy is a relatively common condition of the nervous system, during which a person has repeated seizures. Epilepsy can be found in all ages, genders and cultures. Up to a third of epilepsy cases start during childhood, though it is common for children to outgrow the condition.

Epilepsy is not contagious, nor is it linked to intellectual disability or mental illness. There is no cure, but most cases of epilepsy can be managed by medications.

Causes

The brain is divided into two hemispheres, comprising four lobes - frontal, parietal, temporal and occipital - that each control different functions of the body. Each lobe is made up of millions of nerve cells, called neurons, which use electrical signals to communicate messages to various areas of the body. When faults occur in these signals, they cause an abnormal reaction, called a seizure or fit. Having just one seizure is not considered to be epilepsy; rather, epilepsy refers to a range of conditions characterized by recurrent seizures.

Half of all cases have no known cause. The other cases can be due to a wide range of causes, including:

Types

There are many types of seizures, with some people exhibiting a combination of seizure types. Seizure types can differ depending on the region of the brain it originates in. These include:

Partial (focal) seizures

In partial seizures, the seizure originates in and affects just one hemisphere of the brain. These account for a majority of epilepsy cases. Partial seizures can have two subtypes:

Simple partial seizures

Simple partial seizures affect only a small region within a hemisphere. The symptoms vary according to where the seizure occurs. A person may experience unusual sensations and feelings such as fear, nausea, joy or anger while remaining conscious throughout. Alternatively, they may smell, hear or taste things that do not exist, but seem real to them.

Complex partial seizures

Complex partial seizures affect a greater region within a hemisphere. They often start off as an 'aura' or an unusual feeling, warning them they are about to have a seizure. This leads to a change in consciousness, often creating a dreamlike state in which a person performs involuntary, repetitive actions (automatisms), such as moving their mouth or blinking. They may still continue to perform routine tasks, but these are pointless or unproductive.

Partial seizures can lead to generalized seizures.

Generalized seizures

Generalized seizures occur when the abnormal electrical activity spreads through both hemispheres of the brain. It results in loss of consciousness and is often followed by confusion once the seizure resolves. There are five main subtypes of generalized seizures:

Absence seizures (Petit Mal)

The person will suddenly stare off into the distance and have no memory of the incident afterwards. Often first appearing in childhood, these can be misinterpreted as vagueness, daydreaming or simply 'zoning out'.

Tonic-clonic seizures (Grand Mal)

The person suddenly loses consciousness, drops to the ground and often emits a cry. The body usually goes stiff (tonic) before making jerking (clonic) movements, which can be distressing to watch. Often the person will lose bladder control, bite their tongue and, due to lack of oxygen, their lips may appear blue (cyanosis). Afterwards the person may get a headache and be agitated, tired and sore.

Clonic seizures

The person will experience jerking movements on both sides of the body.

Atonic seizures

The person may have sudden loss of muscle tone, either falling over suddenly or with just their head drooping.

Myoclonic seizures

These cause jerking or twitching movements of the arms, legs or upper body and usually involve both sides of the body.

Brainwave activity during a partial and generalized epileptic seizure. 

Non-epileptic seizures

Not all seizures are due to epilepsy. A range of other conditions can also cause seizures:

Febrile convulsions

In childhood, a high temperature can result in febrile convulsions (seizures), but usually these do not lead to epilepsy. Sometimes, a seizure can be the result of an infection, illness or trauma.

Eclampsia

During pregnancy, this life-threatening condition may lead to seizures and elevated blood pressure, requiring immediate hospitalization. After delivery, the mother usually returns to normal health without further symptoms.

First seizures

Many people experience a one-off seizure, due to a reaction to strong medications or for no known reason. Usually there are no further seizures unless there is a brain abnormality, family history or brain damage discovered.

What can trigger a seizure?

Common triggers for seizures include:

Signs and symptoms

Most seizures last less than a few minutes, but some may last longer. Seizures can result in repetitive, jerking movements (convulsive seizures), but also other unusual feelings, sensations and behaviors (non-convulsive seizures). These non-convulsive seizures can depend on the regions of the brain that are affected and include:

In simple partial seizures, individuals remain conscious, whereas in complex partial and generalized seizures, a person's consciousness is altered.

Some people report an 'aura', which are feelings or sensations that precede a seizure. They serve to warn people that they are about to have a seizure. During convulsive seizures, people may accidentally bite their tongue, and lose control of their bladder and bowel. Following generalized seizures, people can often feel confused.

There are over 40 different types of epilepsy syndromes, with different patterns of symptoms.

Methods for diagnosis

Medical history

A doctor will take a person's detailed history about previous seizures, illnesses, family history and relevant symptoms, to investigate the type of seizure being experienced. As the patient may not remember what happened during a seizure, any information from caregivers or bystanders can be helpful.

Blood tests

Blood tests will be used to detect infections, anemia, diabetes, metabolic disorders or poisons that may be contributing to seizures.

Neurological, developmental and behavioral testing

Motor skills, intellectual ability and emotional behaviors may be tested.

Procedures

Electroencephalogram (EEG) monitoring

This test examines the electrical activity in the brain using video monitoring and electrodes, which are applied to the scalp. It can be performed while awake and/or during sleep, to detect any abnormal brainwave patterns. This test can help identify the type and origin of epileptic seizures.

Electroencephalograph (EEG) monitoring. 

Scans

The following scans can be used to evaluate the brain activity:

Types of treatment

How to manage a seizure?

The first-aid management of an unconscious person with a seizure requires you to time the seizure if possible and to protect the person by:

Gently roll the person onto one side and stay with them, talking calmly to them until they regain consciousness.

If the person does not regain consciousness between repeated seizures, they are continuous, or last more than five minutes, call an ambulance immediately. Also call an ambulance if the person is not a known epileptic and is experiencing a seizure.

The first-aid management of a person with confusion due to a seizure is as follows:

Long-term management of epilepsy

Doctors will normally try to first control epilepsy with medications. This may take some time and experimentation, as the dosage is balanced to achieve optimum effect and minimize the side effects. With most forms of epilepsy, the sooner treatment begins, the better the outcome. If the medications do not work, the next step will be to look at diet, surgery, or the possible insertion of a biomedical device with electrodes (similar to a pacemaker) near the collarbone to send signals to the vagus nerve, which runs from the brain stem to the abdomen. This has been shown to reduce the occurrence of seizures.

Medication

Antiepileptic drugs (AEDs) are used to reduce the frequency and severity of seizures. Some can stop seizures completely, but cannot cure epilepsy. While some AEDs may need to be taken long-term, some are phased out over a few years, as symptoms lessen. There are different types of AEDs available; some affect the electrical activity between brain cells by controlling the passage of potassium, sodium, calcium and chloride ions through the cell membranes. Other AEDs work by changing the chemical messages (neurotransmitters) sent between the brain cells. It is vital that a person never suddenly stops taking AEDs, as this can cause severe seizures. Common side effects of AEDs are headaches, nausea, dizziness, rashes and weight changes. Contact a doctor immediately if a skin rash develops while taking AEDs, as this is one sign of a potentially fatal drug reaction.

Surgery

If seizures are due to an abnormality within a certain area of the brain (focal point), surgery may be offered to remove the affected region. Extensive testing is essential to ensure the correct area is targeted and no damage caused to vital functions such as vision, speech or movement. Surgery is therefore performed only under a local anesthetic, enabling the patient to stay conscious while the surgeon checks the functionality of vital areas before and during the operation. Prior to any surgery, there is an extensive period of testing/examination and counselling over several months, to make sure this is the right solution and to weigh the benefits against any possible side effects. Removing the affected part of the brain can result in lessening of seizures or in some cases, stop them all together. However, some cases cannot be operated on, due to the sensitive location of the affected area.

Ketogenic diet

This is a high-fat and low-carbohydrate diet often recommended for children with severe seizures who do not respond well to medication. The basis of the diet is to get the body to burn fats instead of glucose (sugars), which seems to affect brain chemistry thereby reducing seizures. Due to the diet potentially causing nutritional deficiencies, this procedure requires the close supervision of a dietitian.

Vagus nerve stimulation (VNS)

The vagus nerve in the neck is stimulated with an electrical device similar to a pacemaker placed in the chest, just under the skin. It sends electrical impulses to the nerve. It is not understood how it works, but VNS can, in some cases, reduce seizures by 20-40%, enabling a reduction in prescribed medication. VNS is used for focal seizures in people aged over 12 who do not respond well to medication. Side effects are coughing, a sore throat and problems with breathing during sleep (sleep apnea).

Potential complications

Driving

In the US, all states allow people with epilepsy to drive. Each state has its own regulations and they can vary greatly. The Epilepsy Foundation has a searchable database of state regulations on its website. You can visit the your state's department of motor vehicles (DMV) website to find the requirements in your state.

In all cases, people with epilepsy must report their condition to their state's DMV. However, states require different people to do the reporting. Some want the doctor to contact the DMV. Others need the person with epilepsy to sign a simple form at the time of application for a license or renewal that says they'll notify the DMV of changes in their health status or driving ability.

Mental health issues

People with epilepsy are at higher risk of developing depression and anxiety. This may be due to medication side effects and not feeling 'normal' due to social embarrassment from having seizures. Lack of independence and social exclusion may also contribute to depression.

Drowning

There is a much higher risk of drowning while swimming or bathing for anyone who suffers from seizures or epilepsy.

Pregnancy complications

Many antiepileptic medications can cause birth defects, so it is important for a woman with epilepsy to talk to their doctor prior to becoming pregnant. As seizures can be harmful for both the mother and unborn child, close medical monitoring is also required during pregnancy.

Sudden unexplained death in epilepsy (SUDEP)

Although incredibly rare, people with epilepsy are at greater risk of sudden unexplained death. The reason for this is unknown, but may be due to changes in the heart or brain function. Those with uncontrolled epilepsy face an even higher risk.

Status epilepticus (SE)

This is when a seizure lasts for more than five minutes, or the person has continuous seizures. This condition requires urgent medical attention as it can lead to permanent brain damage or death.

Prognosis

The outlook for the majority of people with epilepsy is positive, with most leading a full and active life. Medical research continues to explore genetic factors, and brain surgery is now a highly advanced and safe procedure. With the use of biomedical devices, antiepileptic medications, specialist diets and lifestyle modifications, many will be able to control most of their symptoms. Epilepsy that starts in childhood usually improves or even disappears with age.

Prevention

There are several things a person can do to reduce the chances of seizures:

References

  1. Epilepsy - overview - National Library of Medicine - PubMed Health. (-a). Accessed 29 September 2014 from link here
  2. Epilepsy Australia. Accessed 29 September 2014 from link here
  3. How anti-epileptic drugs work | Epilepsy Society. Accessed 29 September 2014 from link here
  4. Lennox-Gastaut Syndrome Information Page: National Institute of Neurological Disorders and Stroke (NINDS). Accessed 29 September 2014 from link here
  5. Neurology : Antiepileptic medications. Accessed 29 September 2014 from link here
  6. Provider of Specialist Epilepsy Services | Epilepsy Action Australia. Accessed 29 September 2014 from link here
  7. Types of Seizures | Epilepsy Foundation. Accessed 29 September 2014 from link here

9 Most frequently asked questions (FAQs)

What is epilepsy?
Epilepsy is a disorder of the brain that makes a person prone to seizures. A seizure is a temporary disturbance of electrical activity in the brain. Symptoms can include muscle stiffness, fits, twitching, blackouts, and abnormal sensations and emotions.
What are the causes and triggers of epilepsy?
In most cases, the cause of epilepsy is unknown. Other causes of epilepsy include structural abnormalities in the developing brain, brain infections such as meningitis and encephalitis, brain damage, a brain tumor, strokes and dementia. Drug or alcohol abuse can also lead to epilepsy. A person with epilepsy may notice certain triggers. These may range from emotional stress, sleep deprivation, skipping meals, menstruation, alcohol use or withdrawal, and fevers.
What are the different types of seizures?
Seizures can be divided into generalized seizures and partial (focal) seizures. Generalized seizures involve the whole brain. Partial or focal seizures are seizures that start from a restricted area of the brain. Partial seizures can be further divided into simple partial seizures and complex partial seizures. Simple seizures do not cause a loss of consciousness, whereas complex partial seizures cause an impairment of consciousness.
What are the symptoms of seizures?
Symptoms of seizures depend on the seizure type and the part of the brain it starts in. Some symptoms of focal seizure include muscle jerking or twitching on one side of the body, repetitive movements such as chewing or blinking, and periods of staring. Some people with focal seizures also experience smelling strange smells and changes in their vision. Focal seizures may be preceded by an 'aura', a collection of distinctive sensations before a seizure occurs. Symptoms of generalized seizures include stiffening of the muscles, muscle jerking, loss of consciousness and staring episodes. Some people with generalized symptoms may bite their lip or tongue while having a seizure and lose control of their bladder and/or bowels.
Can someone with epilepsy have a baby?
Many women with epilepsy can become pregnant and have a healthy baby. However, women should tell their doctors if they plan a pregnancy, as close monitoring is needed. Medications may also need to be changed as certain antiepileptic (anti-seizure) medications can be harmful to the unborn baby.
How is epilepsy diagnosed?
Epilepsy is diagnosed by a description of the seizure from the patient and a witness. When someone first has a seizure, tests may be ordered to check for other conditions such as low blood sugar and low sodium levels that can cause similar seizures. A CT scan of the brain is often ordered to check for any underlying physical problems. An electroencephalography study (EEG) is also performed. EEG measures electrical activity of the brain and can support the diagnosis. A normal result on EEG does not rule out epilepsy, and several studies may be required.
How is epilepsy treated?
Most people with epilepsy are treated with anti-epileptic medications. Typically, a single anti-epileptic drug is given at a low dose. The dose is then gradually increased until seizures are well controlled. Other drugs may be introduced later on to better control symptoms if needed. Other treatment options include Vagus nerve stimulation, a procedure in which a device is implanted under the skin on the chest. This device sends electrical signals to the brain via the Vagus nerve in the neck. Special diets may also be suggested in uncontrolled epilepsy. Surgery may be recommended in cases that do not improve with medication. Treatment also involves avoiding triggers that cause seizures, such as sleep deprivation, alcohol, recreational drugs and emotional stress.
Why would a doctor question a diagnosis of epilepsy?
Many conditions may appear similar to epilepsy, including fainting, transient ischemic attacks (mini-strokes), migraines and heart problems. These can be difficult to differentiate from epilepsy. If you do not respond well to antiepileptic medications and EEG tests and MRI scans are normal, your doctor may order further tests to better understand your condition.
What restrictions are placed on driving vehicles?
Each state has different laws for people driving after a seizure. It is best to ask your doctor to check your state's requirements. Most states require a certain period of seizure-free time before you can drive. It is not possible to obtain a heavy vehicle license if you have had a seizure.

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About this article

Title: Epilepsy

Author: Karen McCloskey BHSc

First Published: 30 Nov 2014

Last reviewed: 17 Jan 2022

Category: Information on Epilepsy

Average rating: 4.7 out of 5 (1399 votes)

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