Types of seizures

In general

The different types of seizures seen in epileptic patients can be classified in many ways; by symptoms, by the cause of the epilepsy, by the area of the brain from which the abnormal electrical discharges originate, or by the changes observed on EEG.

It is necessary to classify seizures, since treatment differs according to seizure type. Seen in a larger perspective, such a classification enables doctors, both nationally and internationally to "speak the same language" and thereby exchange both the results of research and their experience in treating patients. This is a prerequisite for any advance in the treatment of epilepsy to be made.

The international classification, as used today, takes account of both the symptoms during a seizure, and of the localization of the abnormal electrical activity in the brain.

Seizures can be divided into the following groups:

The abnormal discharges which generate generalized seizures originate in the central part of the brain and spread simultaneously to the entire surface, in an interplay between the cerebral cortex and the centre of the brain. The patient in this situation rarely knows that a seizure is on the way. Generalized electrical discharges in the brain often lead to loss of consciousness.

One can identify the following generalized seizure types:

Tonic / clonic convulsions

Generalized convulsions were previously often called grand mal or the "falling sickness". The person falls to the ground without warning, sometimes with a scream. Breathing stops, the arms and legs become rigid (the tonic phase) following which the person begins shaking and jerking (the clonic phase). After this the person lies still, often blue in the face, until normal breathing begins again by itself. Most people sink into a deep sleep after a seizure, for a shorter or longer period. This often leads to the misconception that they are still unconscious. It is in fact just a very deep sleep.

Tongue biting

During the seizure the person may foam at the mouth. This is caused by a build-up of saliva and slime in the throat. If the person bites his tongue during the seizure, the resulting mixture of foam and blood can appear very dramatic. Tongue and cheek bites are not very dangerous, although they can be painful for some days afterwards. They are nearly always surface wounds which heal quickly. There is no record of a person biting his tongue off during a seizure. In the past a "bite pin" was often used, a pencil or whatever came to hand, to prevent tongue biting. This is quite unnecessary and can be dangerous as teeth can break off due to the violent clenching during a seizure. At worst the broken tooth could go down the wind pipe and cause breathing problems or even an abscess in the lungs.

Some people may lose bladder and rectal control during a seizure. On awaking they will have no memory (amnesia) of what has happened, they are often tired and may have a headache and muscular pain from all the exertion they have been through. Seizures can vary in duration, but most last no longer than 1-2 minutes.

How to help

A seizure looks very dramatic, but one must remember that the person is completely unconscious and feels no pain. If you should witness a seizure there are only a few things you should do to help the person involved in the best possible way.

You should not normally try to touch or move the person, as this can strengthen or prolong the seizure. If the person is in danger of banging his head, perhaps against the curbstones, you should try to prevent this happening. You should also try to loosen tight clothing such as belts or ties. When the seizure is over, turn the person over into the NATO position to prevent slime and blood entering the lungs. As long as the person comes round again in a short time, it should not be necessary to call an ambulance. Most persons with epilepsy carry a medicine card, seizure calender or similar identification on them.

24 hour rhythm of seizures

Seizures can occur at all times of the day or night. In certain types of epilepsy, however, there is a pattern in the timing. In hereditary epilepsy or seizures which have developed as a complication of absences (see below), seizures often occur in connection with awakening or shortly afterwards. Generalized convulsions, which occur as a complication of complex partial seizures (see below), often occur during sleep.

In many persons whose epilepsy has a known cause, as well as some persons with metabolic epilepsy, there is no connection between the 24-hour cycle and the time at which their seizures occur.

Simple partial seizures are defined as seizures caused by localized abnormal discharges which do not affect consciousness. Simple partial seizures can develop into complex partial seizures, if consciousness is impaired. Simple partial seizuresare the same as "aura". As the seizures start in a localized area of the brain, the patient will often experience an aura-a warning that a seizure has begun. This aura can differ widely from person to person, but will usually be the same each time for the individual, as the abnormal electrical discharges occur in the same area each time. The most usual aura is an uncharacteristic feeling in the body, rising from the stomach to the head (epigastric aura), but it can also involve light, sound, smell, taste or other sensations. Scalp EEG can be normal during simple partial seizures.

Symptoms

In some circumstances abnormalities will arise in the area of the cerebral cortex which controls the movement of muscles or the sense of touch or pain. The symptoms will depend on whether the area affected controls the face, the arms or legs, or if it is influencing movement, so-called motor symptoms, which then result in convulsions. If the senses of touch and pain only are affected, the symptoms will consist of numbness and tingling in the affected area.

The abnormal electrical discharges can also occur in the temporal lobe and can give very different symptoms. In some cases the seizure will start as a simple partial seizure which then develops into a complex partial seizure with impairment of consciousness,.

Sensory phenomena

Sensory phenomena can occur during simple partial seizures, and can be recollected afterwards, often leading patients to speculate as to whether they are going mad. During seizures changes can occur in the perception of:

Time (Time seems to pass faster or slower).

Light, sound and space perception (well-known things take on grotesque forms).

Scale perception (surroundings seem very large (macropsia) or very small (micropsia)).

Well-known things or surroundings appear strange (jamais vecu) or vice versa (deja vecu).

Life like dream pictures. A feeling of inner void. Pronounced anxiety or exhilaration.

When the everyday senses are distorted in this way it is understandable that people become frightened and connect their symptoms with mental illness. But the simple explanation is that the abnormal electrical activity disrupts the normal sensory impressions.

Partial seizures can occur at any age, but most often start in adulthood. In some cases the reason is known, in others none can be found. New investigations indicate that the seizures are hereditary in some case, which is not otherwise the case with partial seizures.

A 25 year-old architect was referred to the doctor with simple partial seizures. When he had a seizure he could not speak, and had clonic convulsions in his right arm and leg. He was wide awake and clear-headed during the seizure, but could not stand up when it came. So he lay down on the ground until the attack went over, which took about two minutes. Although the seizures were not in themselves particularly inconvenient, he became more and more afraid of having them, and for a very special reason. He found that people rushed up to him when he lay on the ground and stuffed anything that came to hand into his mouth: dirty handkerchiefs, wallets, keys or pocket-knives. He was wide awake and conscious during the seizure but because of the difficulty he had speaking and the convulsions he could not ask the well-meaning bystanders to leave him alone. Luckily his teeth were not ruined as he did not have a tonic phase with teeth clenching.

A 16-year old boy had had seizures over two years during which he felt happy and exhilarated for about one minute, after which he felt as if he was experiencing something he had lived through before. The seizures ended with blushing, sweating, tiredness and the urge to sleep. These seizures occurred nearly every day. Over the previous two years he had been treated at a children's psychiatric department where it was thought he was suffering from mental illness. His EEG revealed localized changes in one temporal lobe and CT-scanning revealed a tumor. The boy underwent an operation and the tumor turned out to be benign. Before the operation treatment was started with carbamazepine which was effective in controlling his seizures. The treatment was continued after the operation and he had no more seizures in the five years his case was followed.

Automatism

It is during these seizures that the so-called "automatisms" may occur. These are automatic movements where the person may pull at his clothing or the things around him. Lip-smacking, chewing, face-pulling and other aimless repeated movements, the so-called stereotypes, are often seen.

During longer seizures these automatisms can become more complicated, in that the person may carry out complicated meaningful tasks, which he afterwards has no memory of having done. For example, a person when driving a car, could arrive at quite a different place, far from his intended route.

Secondary generalization

A 22-year-old man had suffered from epilepsy since childhood with infrequent convulsive seizures. His temperament was said to be excitable. He became angry for no apparent reason and would throw everything within reach around. With the help of the local authority he trained as a potter. This gave certain problems when he had a tantrum! He broke everything he had made and even broke the molds and tools. It was an expensive problem!

One evening he was being driven home by his fiancee. He had no driving license and could not drive. Suddenly, on the motor way, he demanded to take over the wheel. His fiancee could see that he was getting angry and as he was a powerful young man, she dared not refuse him. He drove for about one kilometer, then slowly regained consciousness and stopped, repeating again and again: "What am I doing?" As they changed seats once more a police car drove past, and stopped, finding their behavior suspicious. They demanded to see their driving licenses. The result was that the young man was fined a fine for driving without a license, and his girlfriend a smaller fine for handing over the wheel to him.

The young man felt that this was unjust as he had no memory of what had happened. He applied for help to the local epilepsy association and was referred to our epilepsy clinic.

We must admit that at first we thought he was just trying to dodge the fine, but when we looked more closely into the incident and his fiancee confirmed all that had happened, we were sure that it was epilepsy that was causing both his infrequent convulsive seizures and the complex partial seizures. All investigations were normal. We therefore gave the patient a diagnostic treatment with carbamazepine. Since that time he has only very rarely had a "tantrum" and has had no seizures. Neither of the young people had to pay their fines. The young man now has his own driving license and is studying for a new career.

A 14-year-old boy had his first seizure in biology class. The teacher had just explained that a particular flower had 4 stamens. At the same moment the boy had a seizure and began shouting:"No, it has ten! It has twenty! It has thirty! It has forty! etc. after which he was confused and slowly regained consciousness. The teacher was understandably displeased at this interruption. As he had had no previous seizures, no one suspected that the boy had epilepsy. The boy himself had no recollection of the incident. A few days later he suddenly threw himself at his girlfriend and seized her breasts. His parents saw this and were angry with him, but the boy had no idea why they were scolding him, as he once again had no memory of what he had just done. Then his parents understood that something was wrong and took him to the doctor. At the epilepsy clinic his EEG showed a pattern typical of partial epilepsy. After treatment was started he still had some seizures, but only at night. He would sit up in bed, mumble, and lie down to sleep again. Only in connection with a change from one drug to another has he had isolated secondary generalized seizures.

No reason has been found for the boy's epilepsy. There was however epilepsy in the family. His sister went to a psychiatrist because she had attacks of anxiety. Her EEG showed that the anxiety attacks in all probability were simple partial seizures. She did not want to try antiepileptic treatment to see if it would help.

A 32-year old man went down to his local supermarket to buy some video tapes. At the very moment he took the tapes from the shelf, he had an automatism. He stuck the tapes under his jacket and left the shop without paying. He was stopped on the threshold by the staff, who took him to the office. He was by now in the reorientation phase, which can take between 5 and 30 minutes before consciousness is regained. When conscious, he told the police that he suffered from epilepsy. But that explanation was brushed aside.

The next day he came to the epilepsy clinic with his wife, both very upset over the scandal, as they saw it, that had broken over them. The clinic contacted the police and explained about automatism, which they documented with photocopies of the relevant pages from a book about epilepsy. The police dropped the case.

A 33-year-old man with known epilepsy with automatisms, went down to a newsagent to buy some magazines. When he was standing at the counter he had an automatism and began sweeping everything that was on the counter onto the floor. The newsagent got angry and thought the customer was trying to provoke a fight, so he beat him up. When the man with epilepsy regained consciousness, he was lying on the floor with the newsagent sitting on top of him. There was blood everywhere. The newsagent held him so firmly he could not move until the police arrived. Then he managed to tell them that he had epilepsy, which they accepted. But he has since been very frightened of having an attack in unaccustomed surroundings.

Causes