Age-linked epilepsy (epileptic syndromes)

By "epileptic syndrome" we mean a collection of symptoms which, taken together, make up a picture of the illness involved.

Today we have a considerable knowledge of which drugs have the best effect in treating each particular syndrome.

Some epileptic syndromes are benign and only need a short period of treatment, or no treatment at all (Rolandic epilepsy), in contrast to other forms where treatment must be continued for a long time.

Some syndromes have well-known complications against which preventative action can be taken at an early stage.

It is important to understand that the definition of epileptic syndromes is a recent development and is still not complete. New syndromes are regularly being described, thus adding to our knowledge of epilepsy.

Frequency

Causes

Treatment

Frequency

There are about 20 new cases each year in Denmark (5 mill. inhabitants).

More boys than girls are affected.

Symptoms

The seizures consist most frequently of sudden short generalized muscular jerks with bending over of the neck and body and bending of the legs. The arms are thrown forward or outward giving rise to the name "salaam convulsions", as the movement can be thought to resemble an Islamic greeting. The seizures can also be limited to the head and neck and appear as a nod. They are often over very short. Seizures often come in series, followed by crying or screaming. The seizures most often occur just as the child is about to fall asleep or just before waking.

EEG shows characteristic changes taking the form of a more or less chaotic pattern, the so-called hypsarrhythmia.

Causes

In about a third of cases no cause can be found. This group is called the cryptogenic. The child's development is normal until the seizures start. Then their mental development suffers a setback.

In the larger group, the symptomatic, the child's development is impaired even before the symptoms appear. Their neurological symptoms indicate that they have a brain disorder. In some of the children in this group this could be the result of damage at birth. More rarely, the reason may be congenital defects, tuberous sclerosis, metabolic disorders of the brain, or infection by bacterial, viral or other micro-organisms.

Course

About 80-90% of the children will be mentally retarded. The progress of this form of epilepsy makes it one of the most serious.

The typical seizures often disappear before the age of 5, but are often replaced by other forms of epileptic seizures or syndromes, the so-called myoclonic-astatic epilepsy (see below).

Treatment with Vigabatrin is most often effective. ACTH (Adreno-Cortico-Trope-Hormone), which is a pituitary hormone, valproate or clonazepam have also proved effective against the seizures.

In general, unfortunately, the medical treatment is not thought to improve mental development.

Frequency

Seizure types

As the name suggests, the child has several different types of seizures. In astatic seizures there is a sudden loss of muscular tone (tonus), causing the child to fall down, often hitting his head or face. These children therefore often wear a protective helmet.

Sudden jerks in a localized group of muscles can also occur, the so-called myoclonic jerks.

Atypical absences also occur. They differ from normal absences (see pyknoleptic petit mal) in that myoclonic jerks and characteristic EEG changes are seen. Lastly, some of the children have generalized convulsions.

Causes

In many cases a the fundamental cause of the illness can be found in an earlier inflammation of the brain, a malformation, a trauma or other illness resulting in the loss of brain tissue.

This syndrome is one of the most serious forms of epilepsy. When symptoms start, about half the children will already be showing signs of poorly developed intelligence. In the course of a few years most will have become mentally handicapped.

Treatment

Frequency

Pyknoleptic petit mal is seen in only a very small percentage of epilepsy patients. This form often begins in childhood, but may start later.

Girls suffer more frequently from absences than boys do.

Seizure types

The characteristic seizure type is an absence, a brief black-out, which occurs frequently, therefore the Greek name, pyknos = close together. During the absences blinking, eye-rolling, face-twitching and more rarely, loss of grasp can be seen.

The child seldom realizes that she has these attacks. The attacks can easily be induced by getting the child to breathe deeply (hyperventilate) for a few minutes. The doctor can thus make the diagnosis without the need of further technical aids. During absences the EEG shows characteristic changes in the form of spike-waves which occur at the rate of 3 per second.

Pyknoleptic petit mal is a typical example of an inherited primary generalized epilepsy; that is to say, one cannot point to any changes in the brain as a cause of the illness. The children are both neurologically and psychologically quite normal.

Course

Treatment

An 8-year old boy was referred to the children's ward after his school had asked for him to be examined. His parents had also noticed that he could be inattentive and stare into space. His mother described how he would often behave strangely the moment he had to do something, for example get onto a bus or train. He had never had convulsions, nor was there any family history of epilepsy.

We asked the boy to breathe in and out rapidly for 1 minute. Before the minute was over he stopped, blinked, and stared with an empty look. Immediately afterwards he regained consciousness, and was not tired, but had no idea why we were sitting looking at him. It was apparent that the boy had absences. An EEG confirmed the diagnosis. Valproate was prescribed and he has been free of absences ever since.

A 35-year old woman was referred to the clinic with frequent absences. She had had epilepsy from the age of 10 with absences and occasional convulsions. There had been others in her family who had had epilepsy, most recently a nephew. She had previously been treated with phenytoin, phenobarbital, primidone, carbamazepine, tridione and ethosuximide without becoming free of attacks. They consisted of quite short periods of reduced consciousness during which she became pale with slight twitching of the eyebrows. She was always quite lucid after the attacks, which lasted 10-20 seconds. EEG confirmed that she had idiopathic epilepsy which took the form of absences. Treatment was started with valproate alone, which prevented most of the seizures. But from time to time she still had an absence. By combining valproate and ethosuximide she became completely seizure free and has continued to be so. Because of side effects the treatment was later changed to levetiracetam with freedom of seizures and side effects.

EEG

EEG shows characteristic changes in the form of spikes centrally above the one temporal region, a so-called centro-temporal spike focus. EEG changes can, with time move from the one side to the other.

Although the seizures are partial, there is no organic brain damage behind this form of epilepsy. It is therefore not necessary to make complicated tests to eliminate such a possibility existing. The children are quite normal.

Treatment

A 10-year-old boy was admitted to the children's ward after his parents one night had witnessed him having a seizure with convulsions. They had previously heard lip smacking and gurgling noises coming from his bed room at night, without attaching much importance to it. On the most recent occasion they had actually seen that he had had generalized convulsions.

The boy was lively and quite normal during the neurological examination. An EEG showed local changes typical of Rolandic epilepsy. As we had to take account of the fact that the boy had had other attacks over the previous months, he was treated with oxcarbazepine, which gave him freedom from attacks. His parents were reassured to learn that it was a relatively harmless form of epilepsy, which he would grow out of. Although EEG showed localized changes, there was no need to make an MR scan.

Frequency

Seizure types

Myoclonic jerks of the head and arms frequently occur on awakening. They are caused by the sudden contraction of one or more groups of muscles and can result in the person flings whatever she is holding away from herself. These jerks often come in series. Many patients are unaware that this phenomenon can be connected with epilepsy, and the doctor has to question specifically to establish if these symptoms are present.

Generalized convulsions occur most often during the first hours after waking, typically in the bathroom after a series of myoclonic jerks. Myoclonic jerks can have occurred over a period of months or years, before convulsions begin.

Some persons have brief absences as well. More rarely, atonic seizures are seen, in which the person falls to the ground and may hurt himself.

Lack of sleep and the effects of alcohol are definitely seizure-provocative in all types of epilepsy, and in this type particularly so.

EEG

Causes

There is a definite hereditary tendency towards juvenile myoclonic epilepsy. In addition to other cases of epilepsy in the family, typical EEG changes without seizures are often seen in close family members.

It is today discussed that the hereditary factor for this syndrome may be found in chromosome # 6. Brain damage never causes this type of epilepsy.

As far as treatment is concerned, it is of the greatest importance to find out if the patient has this type of epilepsy. Juvenile myoclonic epilepsy is often overlooked, and taken to be epilepsy with generalized convulsive seizures. Then treatment with carbamazepine is chosen, which has a very poor or no effect against the convulsions caused by juvenile myoclonic epilepsy. The same is true of phenytoin.

The suspicion that it may be a case of juvenile myoclonic epilepsy should arise if all the convulsions occur in the morning, if there are signs of myoclonic jerks, or if the EEG shows the characteristic changes.

Treatment

Course

This is a relatively benign form of epilepsy, most patients becoming completely seizure-free. Despite complete freedom from seizures over many years, continued treatment is, nevertheless, necessary. This is due to a pronounced tendency to develop seizures, if treatment is stopped. More than 90% will experience recurrence of the seizures.

A 15-year old girl was referred to the epilepsy clinic after having had a seizure in the bathroom one morning, half an hour after waking. After much careful questioning, she told us that she often experienced slight jerks, or twitches, in first one, then the other arm. These myoclonic jerks could be so strong that her coffee cup could fly out of her hand. In the summer her father preferred to eat breakfast out on the terrace so as not to have to see her "clumsiness", as he put it.

An EEG examination showed juvenile myoclonic epilepsy. The girl was treated with valproate and became quite free of seizures on a single daily dose. She very occasionally experienced myoclonic jerks after sleeping, also when she had slept in the afternoon. This happened if she had gone to bed late after a party. She also learned, that the risk was greater if she drank alcohol.

A 19-year old student nurse had her first seizure while traveling abroad. She had been getting less sleep than she was used to. After that first seizure she had no more, until she was at the end of the first year of her nursing training, when she had a seizure whilst on a hospital ward. She was then informed that she could not continue her training. It was not acceptable that a nurse had epilepsy. Following examination at the epilepsy clinic she was found to have juvenile myoclonic epilepsy. She was put on valproate treatment and has since been seizure free.

We tried to explain to the School of Nursing that she now was seizure-free and could return to her studies, but they were not prepared to listen. Only after negotiations on the part of a social worker and an appeal to the highest authority, did the girl get readmitted to the school. She is now a qualified nurse. She put on weight due to the valproate treatment, but did not want to stop the treatment and risk another seizure, which would mean losing her job.

She has since had a normal, healthy baby. Early in the pregnancy she had an amnion fluid test, which proved normal.

These are generalized convulsions caused by a temperature of 38 C or higher.

Febrile convulsions occur between the ages of 6 months and 5 years. They are more common in boys than in girls, but the reason for this difference is not known. Although it is not in itself an actual epilepsy, in a quarter of the cases there will be epilepsy in the family.

The fever is most often caused by a virus infection, often influenza, or an illness (3-day fever) accompanied by a rash that resembles measles. In some parts of the world malaria is a common cause. The fever can also be caused by a bladder infection or vaccinations.

Frequency

Febrile convulsions are much more common than epilepsy. They are seen in about 4-5% of all children.

Seizure types

Some children run a high temperature for 24 hours before the convulsions. In about 10% of cases the convulsions occur immediately before the fever is noticed. The convulsions are usually generalized. They often begin with a tonic phase, in which the child becomes stiff, followed by a jerking of the arms and legs (the clonic phase). Partial seizures can occur alone, sometimes followed by a paralysis of the arm or leg which the child had convulsions in. Seizures usually last for about 5 minutes, but can last for up to half an hour. Many convulsions can occur in the course of one illness.

Course

Treatment

If more than one seizure occurs, or if the seizure lasts longer than 2 minutes, emergency treatment should be sought. This consists of the injecting of diazepam or clonazepam into a vein or into the rectum. The child must not be covered and must only have light clothing on. The cause of the fever must be found, and the illness treated if possible.

It is important to exclude the possibility that the child may have an inflammation of the brain or meningitis. As it can be difficult to make a diagnosis, the child should be admitted to hospital in connection with the first seizure. If the diagnosis is febrile convulsions one can consider preventative treatment to avoid further attacks.

There are two forms of treatment. In the first, diazepam is given in the form of a suppository or injection in the rectum, every time the child has a fever, before convulsions occur.

If this form of treatment is impossible, the child should be protected from further attacks by giving it continuous treatment, usually valproate.