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A diagnosis of epilepsy raises many questions and concerns. This section answers some of the most frequently asked questions.
The brain controls the body's action, sensations and emotions through nerve cells that carry messages between the brain and the body. These messages are transmitted through regular electrical impulses. A seizure occurs when sudden bursts of electrical activity in the brain disrupt this pattern. The kind of seizure and the parts of the body affected by it relates to the part of the brain in which the irregular electrical activity occurred. Seizures can involve loss of consciousness, a range of unusual movements, odd feelings and sensations, and changed behaviour.
There are many medical reasons why people lose consciousness, experience periods of time when they are 'not quite with it' or have unusual sensations. These include panic attacks, migraine, faints (sometimes called 'syncope'), seizures, stroke and heart disease. A definite diagnosis is important, but because the person often has little or no memory of the event it can take time to come to the right answer.
The doctor will begin by taking a thorough medical history and examining the patient. Eyewitness accounts can help a great deal with the diagnosis, so it is useful for a friend or family member who saw the event to accompany the patient to the first appointment. If a stranger witnessed the event, a written description or a phone number for the doctor to call can be helpful.
Tests may be arranged, and these will vary depending upon the doctor's initial assessment. They may include blood tests, an EEG [electroencephalogram], a CT scan [computerized tomography] or an MRI [magnetic resonance imaging].
Sometimes it is very clear why a person has experienced a collapse or 'blackout'. But occasionally, even after all the appropriate tests and a thorough examination of the person's medical history it is still not possible to make a definite diagnosis. This can be frustrating.
Often it is a matter of simply waiting for a definite answer. More events may allow a clear diagnosis, or a further test may show an answer. It is better to be a little uncertain rather than to jump to conclusions and make a wrong diagnosis.
People often assume that tests such as an EEG, a CT scan or an MRI will tell if they have had a seizure. However, information from tests alone cannot confirm that a seizure has occurred. The doctor relies heavily on information from the patient and witnesses to make a diagnosis.
The EEG test records the electrical activity of the brain.However, electrical changes can often be seen only during a seizure, so a normal EEG, taken when a seizure is not occurring, doesn't mean that a seizure has not occurred at some other time. An abnormal EEG can suggest that the person is more likely to have seizures, and this can be helpful to the doctor. However, an EEG can be abnormal for many reasons.
CT and MRI scans show how the brain is built and, occasionally, a possible cause for seizures can be seen on a scan. However, like an EEG, the scans can be normal in people who have seizures, and not everything unusual on a scan will be a cause of seizures.
In some people, the EEG and CT or MRI scans are normal and yet, based on the history, the doctor is certain that the person has had a seizure.
Blood tests check the general health of a person.
EEG records small electrical signals from the brain onto a computer or paper. Small discs called electrodes placed on the scalp with temporary glue pick up the electrical signals and pass them along wires to the EEG machine.
Recordings take about 20 minutes, while patients rest or sleep. At times, patients are required to open and close eyes, breathe deeply or look at flashing lights. EEG tests are safe, painless and do not give electric shocks. For best results, hair must be clean and dry, with no hairspray, mousse, gel or oil.
Sometime, the doctor will request a 'sleep-deprived' EEG and the patient is asked to restrict sleep the night before the test. In drowsy patients, the EEG can occasionally provide additional information.
When an EEG needs to be collected over hours or days, a compact recording machine can be worn by the patient during normal activities.
Sometimes, it is useful to perform an EEG over an extended period while the patient is monitored by a video camera. If an episode occurs and is recorded, the doctor can view a video of the event and a simultaneous EEG recording of brain's activity. Video monitoring is performed in hospital as a day procedure or over several days.
Computerized x-ray techniques reveal obvious structural abnormalities or damage to the brain. The patient lies on a table that allows the head to be scanned by the CT unit. A special dye is usually injected into a blood vessel in the arm to circulate in the blood stream and enhance image quality.
MRI uses harmless magnetic field and radio waves to provide more detail than a CT scan. It produces very clear images of the brain without using x-rays.
The patient lies on a table inside a tunnel-shaped scanner and a mirror provides visual contact with staff. While operating, the machine makes a loud thumping noise. People with metal in their bodies or medical devices such as pacemakers are usually not able to have an MRI.
An electrocardiogram measures the electrical activity of the heart. Sensors called electrodes, which detect the electrical currents, are attached to the chest, arms and legs with suction cups or gel. The information is recorded on a screen or paper. The test is safe and non-invasive.
A holter monitor is used to carry out an ECG over an extended period. Electrodes are attached to the body with adhesive patches and connected to a small recording device which is worn over the shoulder or on a belt. Holter monitoring may uncover a cardiac rhythm problem which only occurs occasionally or at certain time of the day or night.
The Loop monitor is a small device about the size of a matchbox that can be inserted under the skin in the chest area to record heart rhythms over weeks or months. The insertion of the monitor is a short surgical procedure carried out under local anaesthetic.
A tilt table test checks the body's response to sudden changes in blood pressure and heart rate. The patient is strapped to a motorised table that tilts from the lying to standing position. An ECG machine and blood pressure monitor measure changes. A fine tube may be inserted into an arm vein to administer medication. The test aims to identify patients with a tendency to fainting and therefore during the test some patients may black out. This test can sometimes rule out epilepsy.
Many people think the word seizure describes a convulsion, where someone generally becomes unconscious and falls with their limbs jerking. But a convulsion is just one type of seizure, called a tonic clonic seizure or generalized seizure [grand mal seizure or fit].
There are many different types of seizures and in adults most seizures are not convulsions. While many people who experience recurring seizures will experience a convulsive seizure at some time, others experience seizures as episodes where they go blank for a few seconds or minutes, or behave in ways that are out of character, occurring without their conscious control.
Generally, seizures fall into two categories: partial or focal on the one hand and generalized on the other. Partial or focal seizures start in one part of the brain [that is at a focal point in the brain] and, affect that part of the body controlled by that part of the brain. Generalized seizures involve both parts of the brain and therefore involve the whole body. A brief description of the most common seizure types follows:
Simple partial seizures are localised seizures, affecting only one part of the brain. The symptoms the person experiences will depend on the function that part of the brain controls. The seizure may involve the involuntary movement or stiffening of a limb, feelings of deja vu, an unpleasant smell or taste, or sensations in the stomach such as 'butterflies' or nausea. The person remains fully conscious throughout the seizure. The seizure usually lasts for less than a minute and then the person recovers. When a partial seizure spreads and involves the whole brain, it is called a secondarily generalized seizure.
This type of seizure also affects only one part of the brain but the person's conscious state is altered rather than lost. The person may often appear confused and dazed and may do strange and repetitive actions like fiddle with their clothes, make chewing movements or make unusual sounds. These behaviours may also be described as trance-like or robot-like and are called automatisms. This type of seizure can be mistaken for drug or alcohol-affected behaviour or psychiatric disturbance. The seizure usually lasts for one to two minutes but the person may be confused and drowsy for some minutes to several hours afterwards.
There are many types of generalized seizures, some convulsive, others non-convulsive.
This is a brief, repetitive, non-convulsive event, usually occurring in the young, and involves the whole brain. With this type of seizure, the person loses awareness of what is happening around them but they rarely fall to the ground. They simply stare and their eyes might roll back or their eyelids flutter.
It can be difficult to tell the difference between absence seizures and daydreaming. However, absence seizures start suddenly, last a few seconds, then stop suddenly and the person goes on with what they were doing. Although these seizures last only a few seconds, they can occur many times daily, and thus be very disruptive to learning.
Myoclonic seizures are brief, shock-like jerks of a muscle or a group of muscles, usually lasting no more than a second or two. There can be just one, but sometimes many will occur within a short time. As a generalised seizure a loss of consciousness occurs but it is very brief and hardly noticeable.
Tonic clonic seizures are generalized seizures involving the whole brain. It is the seizure type most people think of when they think of epilepsy.
During a tonic clonic seizure a person's body stiffens and they fall to the ground [the tonic phase]. Their limbs then begin to jerk in strong, symmetrical, rhythmic movements [the clonic phase]. The person may dribble from the mouth, go blue or red in the face, or lose control of their bladder and/or bowel.
Although this type of seizure can be frightening to watch, the seizure itself is unlikely to seriously harm the person having the seizure. They may however vomit or bite their tongue and can sometimes injure themselves if they hit nearby objects as they fall or convulse. The seizure generally stops after a few minutes. At this time the person is usually confused and drowsy. They may have a headache and want to sleep. This drowsiness can last for a number of hours. In the event of prolonged seizure activity (more than 5 minutes) it is advisable to call an ambulance.
In tonic seizures the body's muscle tone is greatly increased and the body, arms, or legs make sudden stiffening movements. These seizures most often occur in clusters during sleep. Seizures can occur when the person is awake, and if the person is standing they will fall quite heavily, often injuring their head. Seizure duration is usually less than 20 seconds. If appropriate it is advisable for the person to wear a protective helmet to avoid injury. Seek medical attention if the person is injured.
Atonic seizures are generalized seizures that affect muscle tone causing the person to collapse to the ground. Often called 'drop attacks' or astatic seizures, these seizures can cause head or facial injury. Protective headwear is advisable to avoid constant injury. Recovery is generally quite quick. Seek medical attention if the person is injured.
Seizures are most common in young children and the elderly, but they can occur for the first time at any age.
Sometimes it is easy to see the cause of a seizure. For example, a seizure may occur at the time of a bad head injury or brain infection. Seizures are occasionally caused by high fevers (especially in children), the use of certain drugs or excessive intake of alcohol. In other cases an injury or infection of the brain that happened a long time ago can cause a seizure.
Seizures may also be brought on by significant stress or lack of sleep. These 'triggers' alone, however, do not explain why a seizure has occurred. After all, not everyone who is stressed or sleep-deprived will have a seizure. Tests are still needed to ensure that no other cause can be found. It appears that certain people are simply more prone to having seizures than others. This is, at times, described as having a 'low-seizure threshold' and may be due to an individual's genetic makeup.
In many cases, despite thorough medical investigation, the cause of a seizure cannot be determined.
Experiencing a seizure does not necessarily mean that a person will continue to have seizures. Many people have only one seizure. It's not possible to know for certain who will have more than one. The circumstances of the seizure, the family history or the test results might suggest that the risk of another seizure is higher in some people.
A seizure is the physical sign that there has been a disruption to the normal functioning of the brain. As discussed, there can be quite a few explanations for why seizures occur. However, if a person is told they have epilepsy it simply means that they have started experiencing seizures on a recurring basis. The seizures in epilepsy may be related to a brain injury or a family tendency, but often the cause is completely unknown. They tend to be unpredictable and occur without provocation.
While epilepsy is also known as a seizure disorder, it is not just one disorder. As there are different types of seizures, so too are there different types of epilepsy disorders, called the epilepsies, each with its own particular set of features. When a disorder is defined by a characteristic group of features that usually occur together, it is called a syndrome.
Epilepsy syndromes are defined by a cluster of features. These features include:
By understanding the nature and presentation of a particular syndrome the treating doctor can implement the most appropriate form of treatment and may be able to predict whether seizures will lessen or disappear over time.
Medication does not cure epilepsy but it can prevent seizures occurring. Whether or not to prescribe medication will depend on how highly the doctor rates the risk of another seizure and how seriously this would impact on the person's wellbeing.
Optimally decisions about treatment are made jointly by the doctor and the patient after consideration of each patient's circumstances. The type of seizure will, in part, determine the medication used. Of people at risk of recurring seizures, more than 60% are likely to achieve complete seizure control with medication within a year.
Although the diagnosis and treatment of seizures has improved dramatically in recent years, many in the community are unaware of the latest developments. Resources, including library books and web pages, often contain out-of-date or biased information. Incorrect information can cause unnecessary worry and prolong poor and even ineffective seizure management.
For reliable information on any aspect of seizure diagnosis and management, or support for people affected by seizures contact your Epilepsy Australia Affiliate
Epilepsy Australia National Help Line 1300 852 8653
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