Epilepsy

EPILEPSY - a patient's guide
Dr Logan Mclennan - Family Doctor

Overview

Epilepsy is a disorder where electrical impulses in the brain discharge in an uncoordinated fashion leading to a seizure.

This can happen to any person if a certain threshold of stimulation is reached.

Those people with epilepsy have a lower threshold than the rest of the population.

Many medications exist to control and prevent seizures allowing epileptic people to live full and active lives.

When seizures first appear the person needs to be fully investigated to see if there is a reversible cause.

A description of epilepsy

The word "epilepsy" derives from a Greek word meaning "a condition of being overcome, seized, or attacked." People who had epilepsy were thought to be possessed by a demon when they had a seizure and so epilepsy became a feared and shunned condition. A "seizure" is the word used for an epileptic attack and is a more neutral word than "fit". Because of the stigma that has been attached to epilepsy in the past, it is important to use neutral words.

Epilepsy was mentioned more than 2,000 years before Christ. References can be found in ancient Greek texts and in the Bible. Epilepsy was given serious study for the first time in the 19th century. Sir Charles Locock was the first to introduce a sedative that aided in controlling seizures in 1857. In 1870, John Hughlings Jackson identified the brain's outer layer, the cerebral cortex, as the part involved in epilepsy. Hans Berger demonstrated that the electrical impulses of the human brain could be recorded in 1929.

The brain is made up of billions of cells that are specialised to communicate with each other by carefully controlled electrical and chemical signals. An epileptic seizure can occur when the control goes haywire for a short time and the electric signals go out of control. Anybody can get an epileptic seizure with enough stimuli. The only difference between people with and without epilepsy, is that the threshold for the electrical discharge is set much lower. There are many causes for this threshold being lowered, for example:

low blood sugar

sleep deprivation

head injury leading to scarring on the brain

strokes

brain tumours

problems carrying blood to and from the brain (arterio-venous malformations)

poisoning

fever(febrile convulsion)

brain infection(meningitis)

genetic /hereditary

oxygen lack at birth(rare)

For some people the threshold is just high enough for seizures not to occur unless something happens to temporarily lower the threshold. For example, getting drunk, missing sleep, hyperventilating (rapid deep breathing), flashing lights, pregnancy and hormonal changes (such as in the few days before menstruation).

Sometimes, despite investigations, the cause for epilepsy is unclear and it is called "idiopathic" which is a medical term for "don't know what the cause is". About 65% of epilepsy cases are idiopathic.

Epilepsy occurs in about 0.5 to 1 person in a 100, both males and females and in all races. In some cultures the rate gets up to 4 per 100. Fifty percent of people with epilepsy develop it before the age of 10 years and these people often find that the seizures reduce as they get older. Occasionally they will disappear completely. There is only a slight tendency for epilepsy to be passed on to children by parents through the genes.

Epilepsy also occurs in animals. It is not an infectious disease and cannot be passed on to other people by close contact.

It does not normally affect intelligence or memory. Occasionally retarded people have epilepsy but the epilepsy is then usually secondary to the injury to the brain that has caused the retardation. Usually a seizure will stop by itself within a few minutes. Very rarely, seizures can last a long time (a condition known as status epilepticus) and this can lead to damaged brain cells.

Types of epilepsy

The confusion of names used in describing epilepsy is due to the many varieties of epileptic seizures. There are over 30 different seizure types. The International League Against Epilepsy proposed a new classification some years ago known as " The International Classification of Epilepsy Seizures" which has been adopted internationally and is gradually replacing outdated seizure names such as "grand mal" and "petit mal".

Under this classification there are two major types of seizures: "generalized" and "partial". These categories are then divided into subcategories such as simple partial, complex-partial, absence, tonic-clonic, and other types.

(1) "Generalised" seizures can occur without any warning and there is usually immediate loss of consciousness.

"Generalised minor seizures" are also called absence seizures (formerly called petit mal) and there is loss of consciousness for 5 to 15 seconds without convulsions or shaking. During this time the patient appears to be staring into space and the eyes may roll upwards. Absences are not preceded by an aura and activity can be resumed immediately afterwards. Mostly, they occur in children and are gone by the teenage years. They occasionally evolve into other seizure types, such as complex-partial or tonic-clonic.

"Generalised major seizures" (previously called grand mal) are also called tonic/clonic seizures and have the full pattern of convulsing and shaking sometimes with loss of urine control and tongue biting. The convulsion involves two phases. In the first or tonic phase, the individual loses consciousness and falls, and the body becomes rigid. In the second or clonic phase, the body extremities jerk and twitch. After the seizure, consciousness is regained slowly. If the tonic-clonic seizure begins locally (with a partial seizure) it may be preceded by an "aura". These seizures are said to be secondarily generalised. While the tonic-clonic seizure is the most visible, obvious type of epilepsy, it is not the most common. Partial seizures are more frequently encountered and occur in 62% of all epileptic patients.

(2) "Partial" seizures are often preceded by a sensation or warning called an "aura". The aura may allow the person time to avoid possible injury. The type of aura experienced varies from person to person. Some people feel a change in body temperature, others experience a feeling of tension or anxiety. In some cases, the epileptic aura will be apparent to the person as a musical sound, a strange taste, or even a particular curious odour. If the person is able to give the physician a good description of this aura, it may provide a clue to the part of the brain where the initial discharges originate. An aura could occur without being followed by a seizure. During this type of seizure the patient can experience a range of strange or unusual sensations including sudden, jerky movements of one body part, distortions in hearing or seeing, stomach discomfort, or a sudden sense of fear. Consciousness is not impaired.

The symptoms that occur with partial seizures depend on the parts of the brain involved. Sometimes partial seizures proceed to involve other parts of the brain and become more complex with impairment of consciousness. These complex-partial seizures (formerly called psychomotor or temporal lobe epilepsy) are characterized by a complicated motor act involving impaired consciousness. During the seizure the patient appears dazed and confused. Purposeless behaviours such as random walking, mumbling, head turning, or pulling at clothing may be observed. Usually, these so-called "automatisms" cannot be recalled by the patient. In children this seizure may consist of staring or lip smacking. Complex-partial seizures account for approximately 30% of all cases.

(3) Other names used in describing epilepsy.

Benign rolandic epilepsy is an epileptic syndrome occurring in young children that stops in the teenage years. Salivation, twitching of the mouth or upper extremity on one side are typical manifestations and they almost all occur in sleep.

Juvenile myoclonic epilepsy is an epilepsy characterised by onset in childhood or adolescence and is associated with extremity jerking (myoclonic jerks, especially arms)or generalized tonic clonic seizures ('grand mal') within an hour or two of wakening from sleep. Seizures, which may be precipitated by sleep deprivation, alcohol intake, or coffee, tend to occur in the morning.

"Photosensitive epilepsy" is the name given to a form of the disorder where seizures are triggered by flickering or flashing lights such as sitting too close to a TV screen. Though it occurs more frequently in girls aged 6-12, it can occur at any age and regardless of gender.

(4) Non-epileptic seizures.

Epilepsy is a long term condition of recurrent unprovoked seizures. A few people can have a single seizure that is not epilepsy but this will usually only occur with provocation (e.g. drug or alcohol induced). There are many types of non-epileptic seizures but they differ from epileptic seizures in that there is usually no evidence of abnormal electrical activity in the brain after the seizure, and they do not occur repeatedly. Some of the more common causes of non-epileptic seizures are: low blood sugar, fainting,, stroke, migraine headaches,, drug withdrawal, and extreme stress or anxiety.

(5) Status Epilepticus

Status epilepticus is the term used to describe either a single prolonged seizure (over 30 minutes) or recurrent seizures without recovery of consciousness between attacks. This is a medical emergency and can be life threatening, or cause brain damage.

Investigating epilepsy

There are a number of steps a doctor will take when a person presents with possible epilepsy. A GP will often involve a specialist neurologist.

The first step is recording the story of the seizures. Doctors call this "taking a history". This is the most important step and may involve the doctor seeking out family or friends who have witnessed a seizure, to get a good description of the type of seizure and help rule out any non-epileptic causes for the turns.

Other investigations depend on the age of the patient. Most patients will receive an EEG (electro-encephalogram). This is a painless test that measures the electrical activity produced by the brain. However it is not always a totally accurate test. It can be normal even with epilepsy or may only show up as abnormal after sleep deprivation or during sleep.Occassionally it can show up as abnormal in people without seizures.

People who develop epilepsy should receive special tests such a CT or MRI scan. This is to locate a focus of brain injury or to exclude a tumour.

Treating epilepsy:

Lifestyle factors

Lifestyle factors are very important to reduce the risk of lowering the seizure threshold. Eating meals at regular intervals is more important than the type of food eaten. It is important to get enough sleep because sleep deprivation is known to be an important precipitating factor in lowering the threshold for seizures. Other factors that can lower seizure thresholds include high fever and a lot of excitement. Alcohol can raise and then lower the seizure threshold and thus increases the tendency to have a seizure. There are important interactions between alcohol and seizure medicines.

Some drugs of abuse, especially cocaine and amphetamines, can cause seizures and some prescription medications when taken in large doses can also bring on seizures.

Drug treatment

Treatment of epilepsy is primarily through the use of special anti-convulsant drugs. There are many drugs, and the type prescribed will depend upon the particular needs of the individual. The drugs are prescribed either alone or in a combination. The various drugs or combination of drugs control different types of seizures.

All drugs used in treating epilepsy have a chemical name (known as the generic name) and one or more trade names depending how many different manufacturers make that drug. The generic name will be listed first with the trade name(s) in brackets. Doctors try to get control of epilepsy using one single medication as much as possible. However sometimes two or more anti-epileptic drugs are needed to be used together.

Phenytoin (Dilantin)

This is an older drug that has been the workhorse of epilepsy management but is now becoming a second-line drug due its side effects being greater than some of the newer drugs. It can be used for generalised and partial seizures but does not work against absence seizures. Because side effects such as drowsiness, loss of balance, double vision and slurred speech are dependent on the drug levels in the bloodstream, it is important to do blood tests occasionally to check the level. Even if the dosage is kept within normal levels there are some long-term side effects which can be troublesome. These include swelling of the gums, acne, increased body hair, depression and interference in thinking powers. More than most epileptic drugs, phenytoin can affect other medications such as the oral contraceptive and make it less effective at preventing pregnancy, and can be affected by other drugs such as alcohol. Occasionally a skin rash occurs soon after starting the drug and then it has to be stopped. Phenytoin also has the advantage of being able to be given intravenously to treat status epilepticus.

Sodium valproate (Epilim)

This is a newer drug than Dilantin but there is still a lot of experience gained in its use. It was initially used for primary generalised epilepsy but has been found useful for partial seizures for some patients. It is the drug of first choice for children with absence seizures and in primary generalised seizures and also for juvenile myoclonic seizures. It is less important to monitor blood levels but should be started at a low dose and worked up slowly. If the dose gets too high then side effects such as tremor, emotional irritability and nausea and vomiting can occur. With long-term use some side effects can occur which are not dose-related including weight gain, hair loss and swelling of the ankles and rarely it can cause liver problems.

Carbamazepine (Tegretol)

This is used for generalised and partial seizures and needs to be given twice daily. It is no use in absence seizures. It also can be easily affected by other medication which can make a normal dosage level become an overdose and can interfere with the oral contraceptive and with other medications. Side effects due to overdose include double vision, dizziness, poor balance, nausea and vomiting. Blood tests to check on the level of the drug and white blood cell count are important with carbamazepine particularly when it is first started and if overdose side effects occur. Carbemazepine needs to be started at a low dose with the dosage slowly increased .After 2 to 3 months use further adjustments may be needed. A skin rash can also occur with this drug.

Ethosuximide (Zarontin)

This drug is only useful against absence seizures and is used mostly in children. It has few side effects or interactions with other drugs. Overdose can lead to nausea, vomiting and abdominal pain and headache and dizziness and occasionally it causes rash and lowers blood levels of white blood cells.

Clobazam (Frisium)

This drug is usually used as second-line therapy in resistant epilepsy both generalised and partial. It can be used once a day usually at night. About one third of patients become tolerant to this drug after a few months so it loses some of its effect on seizures. If the dose is too high then side effects such as depression, irritability and drowsiness can occur. This drug should not be stopped suddenly because withdrawal seizures can occur. It needs to be tailed off gradually. It is effective in catamenial seizures (menstruation-related). Some women only need to take this drug for 7 to 10 days per month just before menstruation without using any other drugs.

Clonazepam (Rivotril)

This is usually used as a second-line drug with a once daily dosage. It can be used in resistant absence seizures and in generalised epilepsy but it has the problem of tolerance and side effects such as effects on behaviour in children and drowsiness can limit its usefulness.

Lorazepam (Ativan) or Diazepam(Valium)

These are used only for achieving rapid control of persisting seizures /status epilepticus - usually by intravenous injection .

Lamotrigine (Lamictal)

This is a newer drug used as an add-on agent for partial or generalised seizures that have proved difficult to control. It is usually started at a very low dose and worked up gradually to try and avoid a rash. Sodium valproate can be used with lamotrigine and raises the blood levels of lamotrigine allowing a lower daily dosage.

Vigabatrin (Sabrin)

This drug is used as an add-on agent in refractory partial seizures and in infantile spasm epilepsy. It does not work in generalised epilepsy. Side effects include psychosis, headache, weight gain and depression.

Surgical treatment

Brain surgery is occasionally offered for epilepsy resistant to drug treatment but is usually carried out in special centres. Surgery has been offered for 50 years or more but recent improvements in investigation and in the surgery itself has led to excellent results in appropriate patients . Quite extensive investigation and work-up is required before the surgery. This is to locate the part of the brain causing the seizure activity.

Three kinds of surgery can be performed. The first method involves removing the seizure-causing part (focus)of the brain. The second method involves cutting the connections between brain cells(axons) which conduct the abnormal electrical activity from the originating area to the rest of the brain.This can only be done in certain "silent areas" of the brain which do not control other critical functions(eg speech)

The third type of surgery does not involve an operation on the brain itself. A small pacemaker-like device is placed under the skin in the upper chest with a wire leading to the vagus nerve in the side of the neck, and periodically stimulates the vagus nerve with a small amount of electrical current. The vagus nerve has many connections to areas in the brain which can produce seizures. By stimulating the vagus nerve, the brain's potential to generate or spread abnormal seizure activity can be reduced.

The Ketogenic diet

This is a special diet, very high in fats and low in carbohydrates, which has been used to treat epilepsy. It results in chemicals in the bloodstream called ketones, which can prevent seizures in some people, especially children. It is usually reserved for epilepsy resistant to drug treatment as it is a very strict diet and difficult to follow. Some children can be helped dramatically, However, it does not always work even if followed conscientiously.This should only be contemplated if advised by a neurologist.

First aid for seizures

The appropriate help for someone who has a seizure depends on the type of seizure. A person experiencing a tonic-clonic seizure will require good first aid .

Tonic-Clonic (Grand Mal)

This type of seizure is often the most dramatic and frightening, but it is important to realize that a person undergoing an epileptic seizure is usually unconscious and feels no pain. The seizure usually lasts only a few minutes. These simple procedures should be followed:

Keep calm. You cannot stop a seizure once it has started. Let the seizure run its course. Do not try to revive the person.

Ease the person to the floor and loosen clothing.

Try to remove any hard, sharp, or hot objects that might injure the person. It may be necessary to place a cushion or soft item under their head.

Turn the person on his or her side, so that the saliva can flow from the mouth.

Do NOT put anything in the person's mouth.

Call an Ambulance immediately and the patient's doctor if they are known to you.

Absence (Petit Mal)

No first aid is required.

Complex-Partial (Psychomotor or Temporal Lobe)

Do NOT restrain the person. Protect him or her by moving sharp or hot objects away.

If wandering occurs, stay with the person and talk quietly.

Simple-Partial (Focal)

No first aid is required.

Other matters about epilepsy

(1) If your child has epilepsy then the school teacher should be informed about the type of seizure, what they look like, their frequency, and any first aid requirements.

(2)It is important to tell your employer if you have epilepsy.This is particularly so if you work with or near moving machinery ,ladders or drive as part of your work.

(3) Pregnancy is a problem for women on anti-epilepsy drugs because of an increased risk of birth defects. The average "normal" rate of birth defects is 2-3%. Women with epilepsy who are not taking drugs have a slightly higher risk of malformations ( in the order of one half percent higher which is small). Women on a single anti-epilepsy drug have a risk of about 6-7%, with some variation with different drugs. Multiple drug combinations increase the risk. Although the drugs may create risks for the baby, without them seizures may even be more frequent during pregnancy, and the seizures themselves harm both the baby and the mother. A doctor may decide to change or reduce a woman's medication if she plans to become pregnant. Any changes in medication must be considered carefully, and a woman should never adjust her own medication.

(4) Although anti-epilepsy drugs have been measured in the breast milk of mothers with epilepsy, the amount is usually too low to harm the child.

(5) In New Zealand a person with epilepsy is not allowed to drive a vehicle until she or he has been on medication for 12 months without having a fit. If medication is stopped then the person has to wait another twelve months without a seizure before driving a vehicle.You should seek advice from your doctor as to the regulations about driving in your own country.

(6) Swimming is a special risk for people with epilepsy. If seizure control is good then the person can swim but should do it in a swimming pool rather than in the sea or a river and should always have a swimming "buddy" who could help them if a seizure occurs. People with epilepsy should avoid diving - either scuba diving or snorkeling.

(7) Children with epilepsy may experience learning or concentration problems because of a neurological disorder which has resulted in the epilepsy or because of side effects from drugs. If a child with epilepsy is having problems at school, either academically or socially, the teacher and the principal should be asked to help. Children with epilepsy should be allowed to take part in all regular school activities,however caution should be exercised with contact sports (risk of provoking a seizure) and swimming

(8) People with epilepsy may develop depression. Longstanding poorly controlled epilepsy may be associated with chronic personality changes. Following seizures some patients may have emotional "swings" or other thinking difficulties. While epilepsy is a medical problem, the person with the seizures must also make a number of emotional adjustments. The first challenge is acceptance of the diagnosis. Initially people with epilepsy and their families may experience shock or denial. Anger, fear, and depression are also common. However, with information and support, people with epilepsy can understand the condition and develop positive coping strategies. It is important to remember that people with epilepsy can, and do, live full, productive lives. If self-esteem becomes a problem, open discussion with supportive friends, family, or a professional counselor can help you develop new ways of coping and a new sense of hope.