Epilepsy

Epilepsy is a common condition of the brain in which a person has a tendency to have recurrent, unprovoked seizures. The brain controls the body’s thoughts, actions, sensations and emotions through nerve cells (neurones) that carry messages between the brain and body as regular electrical impulses.

A seizure occurs when the normal pattern of these impulses is disrupted by a sudden, excessive burst of electrical activity in the brain. The kind of seizure, and how the body is affected, depends on the part of the brain in which the seizure occurs. Seizures can involve loss of consciousness, a range of unusual movements, odd feelings and sensations, or changed behaviour.

Many people have seizures that are not diagnosed as epilepsy. These often have a known cause or provocation and will not happen again unless the same situation occurs. An example is febrile convulsions in infants.

The chance of being diagnosed with epilepsy at some point in life is around 3 per cent. The main treatment is medication, which controls seizures in about 70 per cent (roughly two in three) of people with epilepsy. Other treatment options may be possible for a small number of people if medication does not control their seizures.

Types of seizures#

Many people think a seizure means a convulsion, in which someone becomes unconscious and falls, with stiffness and jerking. This is just one type, called a tonic-clonic seizure (previously known as grand mal). Some people instead have episodes where they “go blank” for a few seconds, while others remain fully conscious and can describe what they experience. For many, awareness is impaired and they may be confused and disorientated during and after the seizure.

A seizure may involve both sides of the brain (a generalised onset seizure) or a small part of the brain (a focal onset seizure). Sometimes a seizure starts as one type and evolves into another, and some people have more than one seizure type.

Generalised onset seizures#

These begin in both halves of the brain at once. Types include:

• Tonic-clonic seizure: consciousness is lost at the start, the muscles stiffen and the person may fall if standing, followed by rhythmic jerking. They may bite their tongue or become incontinent, and are often confused and very tired afterwards.
• Absence seizure: most common in children. The person “goes blank” briefly, may stare and their eyelids may flicker. These can look like daydreaming and go unnoticed, and recovery is usually quick.
• Tonic and atonic seizures: muscle tone suddenly increases or is lost, which can cause a fall, so injuries are common. Recovery is usually rapid.
• Myoclonic seizures: brief muscle jerks that can occur in isolation or in clusters.

Focal onset seizures#

Only part of the brain is affected. The signs and symptoms depend on which part of the brain is involved and which body functions it controls, so symptoms vary from person to person. The two main types are:

• Focal aware seizure: the person stays aware but may have unusual sensations or movements, such as pins and needles, unpleasant smells or tastes, nausea, deja vu, or emotions such as fear. This may come before a different seizure type, in which case it is often called an “aura”.
• Focal seizure with impaired awareness: the person’s conscious state is affected, so they may seem confused or vague and may make strange, repetitive movements such as fiddling with clothing, chewing or unusual sounds. Afterwards they may be confused and drowsy and have little or no memory of the seizure or the events around it.

Causes of epilepsy#

Anything that damages or scars the brain may lead to seizures and epilepsy. There are many possible causes, and not everyone has a clear reason for their epilepsy. In fact, up to half of people with epilepsy do not know the cause. Known causes can include:

• Brain injury
• Stroke
• Brain infection
• Structural abnormalities of the brain
• Genetic factors

Seizures may also appear to be triggered by circumstances such as lack of sleep or significant stress.

Diagnosis#

It is not always easy to confirm that a person has had a seizure, especially if there were no witnesses. Seizures are often unpredictable and infrequent, which makes them difficult to diagnose. Test results may be normal, but the doctor may still be confident a seizure occurred, based on the person’s history and a clear description of the event. Tests and investigations used to diagnose or rule out epilepsy can include:

• Medical history, including a detailed description of the event
• Neurological examination
• Electroencephalogram (EEG)
• Brain imaging such as computed tomography (CT) or magnetic resonance imaging (MRI)
• Pathology tests

Although these examinations may help identify a cause, in many cases they do not.

Treatment with medication#

Medication is the main treatment for epilepsy, with up to 70 per cent of people gaining seizure control with the right medication. However, it is not prescribed for everyone who has a seizure; this depends on the risk of further seizures. When deciding whether to prescribe, and which medication to use, your doctor considers issues such as the type of epilepsy (if known), the likely risk of more seizures, your age, sex, general health and lifestyle, possible side effects, your preferences and cost.

Medications used to control seizures are called antiseizure medications (ASMs). They are not a cure; they aim to control or reduce seizures. Many people achieve control with a single medication, but some need to try more than one, or a combination.

Epilepsy treatment may be lifelong for some people. Some types are age-related and seizures resolve by a certain age, and others have long periods of remission. If you have not had seizures for a long time, you may question the need for ongoing treatment. Any decision to stop medication should be discussed with your specialist and made when you are fully informed. Keep taking your medication exactly as prescribed until you have discussed this with your doctor. Withdrawal should always be done slowly and under the supervision of the prescribing doctor, because suddenly stopping can provoke a seizure and possibly a medical emergency.

Side effects and interactions#

Side effects vary depending on the medication and can include tiredness, dizziness, weight changes, mood disturbance, blurred vision and skin rash. Side effects often occur when starting a medication and usually lessen or disappear after the first few weeks. Tell your doctor if they persist, are intolerable or are listed as serious; the dose may then be lowered or the medication withdrawn.

Antiseizure medications can interact with other medicines and with each other. They may reduce the effect of another medication, such as the contraceptive pill, or another medication may make the antiseizure medication less effective or potentially toxic. Some common over-the-counter products can also affect epilepsy medication. These interactions are highly variable and sometimes unpredictable, so tell your doctor and pharmacist about everything you take, including vitamin supplements and herbal remedies.

Taking antiseizure medication#

• Medication is usually started at a low dose and increased gradually, using a “start low, go slow” approach, until it is effective or starts to cause troublesome side effects.
• Let your doctor guide any dosage changes; do not alter the dose yourself.
• Avoid switching to another brand of the same medication, even if offered by your pharmacist, especially if you have seizure control, as minor differences may cause a seizure or worsen side effects.
• Do not stop antiseizure medication suddenly unless your doctor advises it. A new medication is usually introduced before or while the old one is reduced, and sometimes a combination is used.
• Try not to miss a dose, and ask your doctor what to do if you do.
• A dosette box or pill organiser can help you remember your medication.
• Tell your doctor if side effects occur or if you still have seizures while taking medication.
• Plan ahead so you do not run out, and ask your doctor what to do during illness or diarrhoea, when absorption may be affected.

Medication changes may be needed for women planning a pregnancy, to minimise the risk to mother and baby. Discuss this with your doctor in advance.

Treatment with surgery#

Some people cannot achieve good seizure control despite trying several medications. Epilepsy is sometimes caused by an area of abnormal brain tissue, and if surgery can remove this tissue, seizures can often be greatly reduced or even stopped. Surgery is not a substitute for medication; it is usually considered when medication fails, especially for people with focal onset seizures.

Several tests are needed before deciding whether surgery is suitable. These generally need to confirm that all seizures come from the same place in the brain and that this area is not involved in important functions such as speech or movement. Your doctor will then discuss the possible outcomes so you can make an informed choice. Only a small percentage of people with epilepsy are suitable candidates.

Vagus nerve stimulation#

The vagus nerve stimulator (VNS) is a device implanted in the upper chest that regularly sends electrical signals to the vagus nerve and brain. It may be used when a person has poor seizure control and is not a candidate for surgery. It is uncommon for the VNS to stop seizures completely, but people may have fewer and less severe seizures. The device also lets the person trigger extra stimulation if they feel a seizure starting, which may reduce its severity and recovery time. Other reported benefits include improved alertness, memory, energy and mood. The VNS can take 18 months to 2 years to reach its best effect. It is not a substitute for medication and is only considered when medication is not effective, so check with your specialist about whether it is suitable for you.

Dietary treatment#

The ketogenic diet is a recognised therapy for epilepsy and has been reported to reduce seizures in some people with poorly controlled epilepsy. The diet produces ketones when the body burns fat for energy, a state called ketosis, which causes changes in body chemistry that may help control seizures.

The traditional ketogenic diet is strict and challenging and requires strong commitment from the whole family. Like other treatments it has side effects and must be closely monitored by a dietitian. It is often started in hospital under medical supervision, with blood sugar and ketone levels monitored. It is mostly used in children who have unsuccessfully tried many medications, and is the treatment of choice for certain rare syndromes.

Dietary options have expanded to include the “modified Atkins diet” and the “low-glycaemic index” treatment diet. These are less restrictive and more palatable, and are usually better options for adults and adolescents. The modified Atkins diet has been reported to lower seizure rates in nearly half of adults who try it. Unlike the ketogenic diet, there is no hospital stay, no fasting to start, no food weighing and no counting of calories or fluids, and adults can also lose weight on it if they wish.

Avoiding triggers#

Some people with epilepsy report circumstances that can provoke seizures. These triggers vary from person to person, and avoiding or reducing them may help some people. Not all triggers can be avoided, and seizures can still occur without any obvious trigger. Keeping a seizure diary can highlight patterns and help identify possible triggers. Commonly reported triggers include:

• Lack of sleep
• Missed medication or medication changes
• Alcohol
• Certain drugs (prescription and recreational)
• Flickering lights or patterns
• Stress
• Menstruation
• Illness, especially with diarrhoea or vomiting
• Significant changes in temperature or overheating

Complementary therapies#

Complementary therapies may help a person by improving overall health, which can in turn support seizure control. Many people assume these therapies are safe because they seem more “natural”, but this is not always true. They contain active ingredients and can cause unwanted effects, including allergic reactions, whether ingested, inhaled or applied to the skin. They may also interact with antiseizure medication and affect how it is absorbed, processed or removed from the body. Always seek advice from your specialist or a health professional before starting any complementary therapy.

Key points#

• The main treatment for epilepsy is medication, which can control seizures in about 70 per cent of people with epilepsy.
• Symptoms can vary from person to person depending on where in the brain the seizure occurs.
• Anything that causes damage or scarring to the brain may lead to seizures and epilepsy.
• There are many causes of seizures, and not everyone has a clear reason for their epilepsy.
• Up to half of people with epilepsy do not know the cause of their condition.

Where to get help#