What is it?

Epilepsy is a condition characterised by recurrent unprovoked seizures. Seizures are abnormal electrical discharges in the brain that temporarily disrupt the normal transmission of messages to the body. They can produce alterations in consciousness, cause odd rhythmic or repetitive movements, jerking or twitching of limbs, and/or can lead to convulsions that contract muscles throughout the body. Sometimes seizures are preceded by epileptic auras. Auras are the heightened sensitivity or unusual perception of sight, sound, smell, taste or touch that warn people of an imminent seizure. They may involve sensations, for example, of a cool breeze or a bright light and may include feelings of numbness or nausea. What happens during a seizure episode depends on which part(s) of the brain are affected. Many people with epilepsy experience similar symptoms with each seizure, but some may have a wide variety of symptoms.

Most seizures last a few seconds to a few minutes. If a person’s consciousness is altered or lost, they will frequently not remember what has happened. Those affected may have no after-effects, may have a brief period of confusion, and/or may experience weakness and fatigue that can last for several days. Most seizures do not have a lasting effect on the brain or body, but a loss of consciousness may lead to falls and injuries - especially if the affected person is driving, bathing, cooking or doing other potentially hazardous activities. Seizures that last longer than five to ten minutes are called status epilepticus and require prompt medical attention. Prolonged seizures, longer than 30 minutes, can increase the risk of permanent damage and can in some cases be fatal.

Not every seizure is considered epilepsy. Those that are due to temporary conditions such as a high fever in an infant, acute meningitis or encephalitis, or alcohol or drug withdrawal are not considered unprovoked seizures. Likewise, not every set of symptoms that looks like a seizure is actually caused by changes in brain electrical activity. Fainting, migraine headaches, narcolepsy, drug use, mental illness, and a variety of other conditions that temporarily alter consciousness or perception may produce some of the same symptoms.

Epilepsy is diagnosed when someone has two or more unprovoked seizures at least 24 hours apart. About 1 in 10 adults will experience a single seizure in their lifetime, but most will never have another one. Epilepsy is the most common serious brain disorder in every country in the world today, but its prevalence is difficult to determine. It is estimated that 1-2 per cent of the worldwide population is affected by epilepsy. While epilepsy can affect anyone, children under the age of 2 and adults over 65 are most likely to be affected. The majority of people with epilepsy will respond to treatment, but about 25-30 per cent will continue to have seizures despite treatment.

Any condition that affects the brain has the potential to cause epilepsy. This includes head trauma, abnormal brain development, lack of oxygen during birth, brain tumours, strokes, cerebrovascular disease, toxins such as lead poisoning, infections, neurologic diseases and metabolic disorders. Some forms of epilepsy run in families and are related to genetic defects. The causes of many cases of epilepsy are unknown and are referred to as idiopathic epilepsy.

Epileptic seizures can be classified as either partial (focal) or generalized. Partial seizures originate from a single location in the brain, while generalized seizures involve both sides of the brain. A few seizures may start as partial seizures and then become secondarily generalized. About 60 per cent of people with epilepsy have partial seizures. For more information about types of seizures, visit the Epilepsy Foundation (US) website and read the article Seizures and Syndromes.

Once an effective antiepileptic drug (AED) is found (two or three may be tried), over 70 per cent of patients achieve full seizure control. Should two drugs at adequate doses fail, referral to a specialty center is indicated for further treatment options.

Tests

Laboratory and non-laboratory tests are used to diagnose and monitor epilepsy, to determine what kind(s) of seizures the patient is having, to identify underlying conditions such as toxins, infections, drug or alcohol withdrawal, fever (in a child), or diabetes that may be causing seizures, and to distinguish epilepsy from conditions such as fainting or a stroke that may cause some of the same symptoms.

A medical history, input from the patient, and input from family members who have witnessed a patient’s seizures are important parts of the diagnostic process. The patient may remember a strange smell, an aura, and/or sensations that precede a seizure but may not remember what has happened during the seizure itself. Depending upon the signs and frequency of a person’s seizures, it may take some time to determine the proper diagnosis.

Laboratory Tests
Laboratory tests are primarily used to monitor anti-epileptic medications (AEDs) and to rule out other conditions such as diabetes, anaemia, infection, meningitis or encephalitis. Testing may include:

Seizure Evaluation testing:

• FBC (full blood count) – to evaluate red and white blood cells  
• Glucose – may be increased or decreased with diabetes 
• Electrolytes
• Toxicology, alcohol level
• Cerebrospinal fluid examination – to check for infection and help diagnose meningitis and encephalitis
• Blood culture – to check for septicaemia, infection in the blood

Non-Laboratory Tests

• Electroencephalogram (EEG) – a primary diagnostic tool for epilepsy; it is used to evaluate the brain’s electrical activity and identify changes in brain wave patterns.

Imaging scans:

• Computerised tomography (CT) – identify brain structure abnormalities and tumors
• Magnetic resonance imaging (MRI) – also identify brain abnormalities
• Positron emission tomography (PET) – radioactive material is used to look at active areas of the brain.
• Single-photon emission computerised tomography (SPECT) – radioactive material is used to identify the region of the brain where seizures originate when it is not clear on other scans.

Periodic therapeutic drug monitoring when a patient is taking a specific medication (AED), such as:

• Carbamazepine
• Phenytoin
• Valproic acid
• Phenobarbitone

Some workers in the field consider routine AED levels unnecessary (phenytoin being an exception). The dose is adjusted on the basis of seizure control and adverse effects.

There are situations when AED levels are useful: Once an efficacious dose is established it may be helpful to document a serum concentration; AED levels help to determine drug compliance; they are useful in the management of status epilepticus. They may be useful if there is drug interaction. (e.g. Lamotrigine levels can fall with oral contraceptives)

Treatment

Epilepsy can be successfully treated in most people but not prevented or cured. The risk of epilepsy due to a head injury can be reduced by taking safety measures, such as by wearing a helmet while riding a bicycle or motorcycle and wearing a seat belt while in a car.

In patients who have epilepsy, seizures can often be prevented or decreased in frequency by consistently taking the appropriate anti-epileptic medication such as carbamazepine, phenytoin, phenobarbitone or valproate. The choice of drug depends on the patient and on the type of seizure. A person should work with their doctor to find the right medication(s) and dose.

The number of seizures can also be decreased by avoiding seizure triggers such as sleep deprivation, excessive stress and alcohol consumption, and use of illicit drugs such as cocaine. Treating underlying conditions can also lessen the frequency of seizures.

More information

Healthdirect Australia - Epilepsy

Epilepsy Australia