Pathologies

Epilepsy, the disease

What is epilepsy?

Epilepsy is a chronic neurological disease caused by abnormalities in the Central Nervous System that alter the electrical activity of the brain. This malfunction causes the well-known as epileptic seizures.

It can affect any person, but for this disorder to be diagnosed the patient must have presented more than one seizure. Epileptic seizures originate because neurons (brain cells) suffer physiological changes, which may affect functions such as movement or behaviour.

However, there are many types of seizures and epilepsy and the seizures are not the only symptom of the disease.

It is a disease that with proper diagnosis and adequate treatment can be controlled in a high percentage of cases.

How many people have epilepsy?

Epilepsy is one of the most common neurological conditions. Fifty million people around the world suffer from epilepsy.

Approximately 5-10% of the population will experience a seizure throughout their lives and up to 20% of these will have repeated seizures.

Signs and Symptoms

Epileptic seizures last minutes or seconds and occur suddenly and unexpectedly. The signs or symptoms will depend on the area of the brain where the seizure originates and the spread of epileptic activity to other brain areas.

Therefore, they can cause:

• Rigidity and uncontrolled shaking of one or more parts of the body (such as arms and legs), if the neural discharge affects the brain area responsible for the movement.
• Auditory and visual disturbances
• Loss of consciousness
• Confusion
• Walking around aimlessly
• Speaking in a confused way
• Moving the mouth as if chewing

Types

A seizure occurs when there are unexpected and transitory symptoms and/or signs due to excessive abnormal neural discharge.

The first step to establish epileptic seizures is to classify them into three main groups: partial (or focal) onset, generalized onset, or unknown onset.

1.- Partial

These seizures are those that begin in a certain part of the brain. They can be localized in that area or spread to other areas of the brain.

Partial seizures may be:

• Partial seizures without alteration of consciousness: when there is no alteration in the level of consciousness, the person responding to external stimuli.
• Partial seizures with alteration of consciousness: in this type of seizure consciousness is lost and there can be a feeling of being in a trance. There is involuntary repetition of certain movements.
• Partial motor seizures: produces involuntary movements of different parts of the body.
• Partial non-motor seizures: does not produce involuntary movements of different parts of the body.
• Partial seizures with progression to bilateral tonic-clonic activity: begins as a focal seizure, in a part of the brain, and spreads to the rest becoming a generalized seizure.

2.- Generalized

This type of epileptic seizure affects the whole brain from the start and leads to the loss of consciousness.

It can manifest itself in different ways and the most common are the following:

• Generalized motor seizures: produces involuntary movements of different parts of the body. This in turn may include, among others.
  • Tonic-clonic seizures: they start with the rigidity of the limbs (tonic phase) and then the various parts of the body begin to flail abruptly and involuntarily (clonic phase). As a result, it may cause abrupt falls, biting of the tongue or wetting oneself.
  • Myoclonic seizures: they consist in short and abrupt jerking of the limbs. They last only a few seconds, and are often overlooked.
  • Atonic seizures: the muscles of the whole body relax. It happens so suddenly that the person falls to the ground. Injury can occur, including serious wounds and blows to the head.
  • Tonic seizures: after a sudden loss of consciousness, the muscles of the whole body stiffen for a few seconds, although occasionally it can take a few minutes.

Generalized non-motor seizures: it does not produce involuntary movements of different parts of the body. This group includes:

• Absence seizures: the eye is kept fixed at a specific point and the person loses consciousness. Each episode lasts for a few seconds and the person recovers as if nothing had happened. Since they tend to be brief, it is difficult to notice them.

3.- Unknown onset seizures

Types of Epilepsy

The second level is the classification of the type of epilepsy, which includes four categories: focal epilepsy, generalized epilepsy, generalized and focal epilepsy (combined with focal seizures and generalized seizures) and unknown (when the information available is insufficient for classification).

This type of classification reflects the fact that many types of epilepsy can have several types of seizure. The diagnosis, in all cases, is done on clinical grounds, with the support of the EEG findings.

Epilepsy syndromes

Epilepsy syndromes are a set of symptoms that include epileptic seizures and that are grouped according to some signs and patterns in common, such as the age of onset. In this case there are five groups of epilepsy syndromes:

• Childhood absence epilepsy
• Juvenile absence epilepsy
• Juvenile myoclonic epilepsy
• Epilepsy with generalized tonic-clonic seizures alone
• Self-limiting partial epilepsies

Lennox-Gastaut syndrome

This is a rare neurological disease that appears in childhood. It is one of the most serious forms of epilepsy. It is often also accompanied by delayed psychomotor development, with learning difficulties, memory loss and alterations of movements.

It is characterized by frequent episodes of seizure and by their diversity.

Causes

Idiopathic epilepsy, that is, one in which the cause is unknown, is the most frequent form.

On the other hand, there is secondary or symptomatic epilepsy that can occur for several reasons:

• Brain damage caused by injury before birth or immediately after (for example, choking, or injuries during delivery, low birth weight, etc.).
• Congenital malformations or genetic alterations associated with brain malformations.
• Severe head injury.
• Stroke, which limits the flow of oxygen to the brain.
• Brain infections such as meningitis and encephalitis.
• Certain genetic syndromes.
• Brain tumours.

Treatment

Nowadays, the aim of the treatment is to reduce the frequency of seizures and improve overall quality of life of the person with epilepsy.

Pharmacological Treatment

The pharmacological treatment is selected by the doctor taking into account the type of epilepsy that the patient is suffering, as well as the patient’s characteristics (sex, age, weight, associated diseases…).

The doctor chooses the drug to try to treat the epilepsy syndrome that the patient suffers, but if this is unknown the choice is made based on the type of seizure the patient suffers.

The choice of the first antiepileptic drug is very important as it is usually given over the years. Based on experience, treatment with a single drug is often effective in controlling seizures, which is known as monotherapy. In addition, it promotes compliance with the dose and adherence on the part of the patient and decreases the risk of adverse effects. However, sometimes it is necessary to use several drugs to control epilepsy.

There are first, second and third generation anti-epileptic drugs. The first generation of drugs presented interactions when several drugs were administered simultaneously. But the evolution of these drugs is allowing the latest generation to have fewer or no interactions with other antiepileptic drugs.

However, each drug has its indications, contraindications and side effects.

Suppression of chronic antiepileptic treatment.

More than 60% of epileptic patients with antiepileptic treatment have an extended period in which their epileptic seizures go into remission. The decision in those cases to withdraw any such treatment in these patients entails an assessment of both the risks and the benefits.

Among the benefits is to avoid the possible adverse effects of chronic treatment, especially important for its impact on children. In women of childbearing age, treatment can influence the effectiveness of oral contraceptives and lead to malformations in the foetus.

In terms of risks, adults can suffer a relapse that might increase the likelihood of severe injuries, loss of driver’s license or work, etc.

It is also known that the risk of a return of a seizure is greater between the first year and two years after the withdrawal of treatment and those who suspend treatment suffer more relapses than patients who continue with it.

To assess the risk of recurrences, doctors take into account the origin of the epilepsy and epilepsy syndrome that the patient suffers, as well as the following factors:

• Free of seizures for 2 and 5 years after treatment with antiepileptic drugs.
• Seizures are partial or generalized tonic-clonic seizures.
• The neurological exam/IQ is normal.
• The electroencephalogram has normalized with the treatment.

If these requirements are met, based on experience, clinicians can expect a withdrawal of the antiepileptic drug without the emergence of new seizures in 69% of children and 61% of adults.

However, the clinical practice guidelines recommend that the patient is informed of the risks and benefits before making a final decision.

Non-pharmacological treatment

Surgical

Epilepsy surgery is a possible option for people who do not respond to treatment with antiepileptic drugs.

Those most likely to benefit from surgery are people with drug-resistant focal epilepsy, especially epilepsy caused by an injury (myocardial infarction, malformations, etc.).

The goal of surgery is to remove the epileptogenic area or area of the brain where seizures originate. The best results are obtained in people with well-defined lesions on neuroimaging studies.

Given the complexity of the intervention, it is very important to select the proper patient and conduct the treatment in multidisciplinary specialized units.

The vagus nerve stimulator

This technique consists in stimulating the left vagus nerve using impulses. To achieve this, a programmable generator, of a size similar to a cardiac pacemaker, is placed in the chest wall through a simple surgical intervention.

The generator is activated two weeks after implantation to allow the healing of the wound. It sends electrical signals on a regular basis to the vagus nerve.

The vagus nerve stimulator is indicated for patients older than 12 years with focal refractory epilepsy, who might benefit from epilepsy surgery. It helps to reduce the number of seizures.

The ketogenic diet

The objective of this diet is to eat foods that may help control seizures. It is based on a diet rich in lipids (fats) and low in carbohydrates (sugars).

There are different types of ketogenic diets. Implementation and monitoring must be performed by nutritionists. At the beginning the patient must be hospitalized because it is implemented little by little for three days to see how the body reacts.

In addition to the continued follow-up by the neurologist or paediatric neurologist, it is essential to have the collaboration of the endocrinologist.

In some types of epilepsy, especially in children, this diet has proven effective.

Epileptic Patient

Emergency services for epileptic seizures

Without a history of seizure

When the first seizure occurs, call or go to an emergency service to make a diagnosis and obtain appropriate treatment.

It is important to:

• Try to remain calm and avoid crowding around the person.
• Observe the characteristics of the seizure to report this to the doctor.
• Look at the clock in order to note the duration of the seizure.
• Put the person on the floor, on his/her side and with head lower than the rest of the body to make it easier to breathe.
• Remove objects that the person could strike and be injured.
• Avoid hitting the head or suffering sharp falls.
• Do not try to restrain the person to stop the seizure.
• Do not try to open the mouth; do not put any objects in it.
• Stay at the person’s side until he or she regains consciousness.

Patient with Epilepsy

Adults with epilepsy can get to know when they are beginning to suffer an epileptic seizure, but in children it tends to be the people around them who can recognize its onset.

In the event of a seizure, especially the most dangerous ones, such as the generalized, it is necessary to ensure a correct patient care and avoid injuries during the seizure:

• Put the patient in bed on his or her side.
• Do not put any objects in the mouth.
• Do not restrain the person by force during the seizure.
• Unbutton clothing if it is too tight.
• Remove the glasses and other objects that could hurt the person.
• Let the person recover from the seizure.
• If the seizure lasts for more than 5 minutes, despite administration of medication, the recovery period after the seizure is very long (over an hour), or any injury is suffered, it is necessary to go to emergency services.