Epilepsy usually involves an obvious and sudden change in behaviour and movement. Even so it is difficult to diagnose. A number of common events, such as fainting and migraines, can be confused with seizures.
This is an abrupt and short-lived loss of consciousness due to a sudden decrease in blood flow to the brain. Fainting is most commonly confused with epilepsy because the person can experience brief jerks, twitching or convulsive movements while they are unconscious.
Up to 50 percent of children and adolescents, and six percent of the general population experience episodes of fainting. Like epilepsy, fainting is identified through a clinical diagnosis, and an eyewitness account is invaluable. Fainting has many causes and triggers, and a good history of the episode can often help to differentiate between a faint and a seizure.
When someone has a seizure immediately following a faint, it is known as a convulsive syncope.
While convulsive syncope can be difficult to differentiate from epilepsy, the condition is usually very easy to treat.
This is a severe type of headache sometimes associated with symptoms such as:
- flashes of light
- blind spots
- tingling sensations in the limbs
- nausea and/or vomiting
- extreme sensitivity to light and sound
Migraine pain can be excruciating and can incapacitate sufferers for hours or even days. There are several reasons why migraine attacks may be confused with epileptic seizures. Fainting may occur during the course of the migraine, particularly when vomiting occurs. Some types of migraine may begin with loss of consciousness and other symptoms, and then be followed by headache. When visual or sensory changes occur, they may be mistaken for partial seizures. However, migraines usually last a lot longer than seizures. It should also be noted that non-specific EEG changes are often seen in people who have migraine.
Transient ischaemic attacks
These are often termed ''mini strokes'' and as the name suggests, are only temporary. They occur because of a brief period of insufficient blood supply to certain areas of the brain, usually resolving within 24 hours. The person can experience weakness and sensory changes, such as numbness and tingling, and often these symptoms are what may be confused with epileptic seizures. TIAs usually last longer than seizures and loss of consciousness is rare.
Like seizures, sleep disorders can be characterised by confusion, unusual behaviour and abnormal movements. Sleep disorders that may be confused with epilepsy include night terrors, sleep walking, movement disorders, bed wetting, sleep apnoea, REM sleep behaviour disorders and narcolepsy. On rare occasions, extended periods of sleep apnoea may lead to a seizure, but this is not considered epilepsy.
These are sudden falls to the ground without warning. They occur during tonic or atonic seizures, however they also can happen when someone has a condition such as:
- Meniere's disease which affects the inner ear
- Narcolepsy a sleep disorder
- Cardiac conditions or atherosclerosis (clogging of the arteries)
Dizzy spells can be caused by any number of circumstances, including the conditions listed in the point above.
This describes a group of neurological disorders that involve the muscles and movement systems of the body. Tics and involuntary movements may sometimes be confused with myoclonic seizures or simple partial seizures. However movement disorders are not associated with loss of consciousness or EEG abnormalities, although the condition often responds to antiepileptic medication.
There are many different causes of movement disorders including Parkinson’s Disease, Huntington's Chorea, Tourette's Syndrome, sleep disorders and essential tremor.
These are common in children aged 18 months to six years. They usually occur after the child has become frightened or upset. The child may cry for a short time then subsequently lose their breath. They can then become limp, faint, arch their back or jerk their limbs.
Sometimes breath-holding can lead to a seizure, but this is not considered epilepsy.
Daydreamers can appear vacant, stare unintentionally and not respond for a short time. In children this is common and can be confused with absence seizures. The difference is that daydreamers will respond to touch or loud noises while someone having an absence seizure will not.
These occur when the heart isn't functioning properly. Examples are when a person has an irregular heart rate or clogging of the arteries which can cause dizziness or blackouts, depending on the severity of the condition.
A febrile convulsion is a fit or seizure that occurs in babies, toddlers and children when they have a high fever. This happens because the developing brain of a toddler or child is more sensitive to fever than an adult brain. There also appears to be a tendency for these seizures to run in families.
Between two to four percent of children have one or more febrile convulsions by the age of five years. Approximately 65 percent of these children will only have the one seizure, while some children will have more than one and others will have a seizure every time they get a fever. For most children with febrile convulsions, the risk of later epilepsy is little different from that of the general population and their intellect and development is not affected.
A very small proportion of febrile seizures are more complex that is, prolonged (> 15mins) and/or multiple seizures in a short period, or they are focal. In this group the risk of developing epilepsy is higher but still low.
Concussion (impact convulsions)
Very occasionally, convulsions can occur within seconds of a head impact such as in a game of contact sport. They are not associated with any structural brain injury and do not lead to further seizures or epilepsy.
These are also known as anxiety attacks. Common symptoms include:
- Increased heart rate
- Feeling faint
- Difficulty in breathing
- Smothering sensation
- Chest pain
- Feelings of anxiety
- Sense of unreality
- Feelings of impending doom
- Fear of loss of control
Some people genuinely believe they're having a heart attack, are losing their mind, or are on the verge of death. Panic attacks can occur at any time, even during sleep. An attack generally peaks within 10 minutes, but some symptoms may last much longer.
Usually it is possible to identify these attacks from the person's descriptions of what happened. Occasionally seizures of temporal lobe origin may cause similar symptoms.
Rage attacks (episodic dyscontrol syndrome)
These are sudden explosive outbursts that appear often and without warning, are out of control and totally out of context to any triggering event in the environment. The events seem out of character and are sometimes attributed to epilepsy. In practice, however, rage that occurs with, before or after an epileptic seizure is unprovoked and usually undirected.
Non-epileptic events (pseudoseizures or psychogenic seizures)
These are characterised by a change in a person's behaviour, perception, thinking or feeling which can resemble, or be mistaken for, a seizure. However the event does not have the characteristic EEG changes that accompany a true epileptic seizure. This attack has an emotional or psychological cause rather than a physiological one and can be seen in people with or without epilepsy. Around 15-22 percent of people who are referred to epilepsy centres for investigation of poorly controlled seizures have had non-epileptic events.
Test for seizures
The best way to find out if an episode is a seizure is to record the event on a video EEG. Unfortunately capturing the event can be difficult, as they are usually sporadic and unpredictable. Therefore a careful description of what happened is extremely valuable. Diagnosis is more difficult without this eyewitness account. Sometimes a home video of the event can also help.
It is important to obtain a correct diagnosis to avoid being treated with medication unnecessarily. Unfortunately, this does happen. In these cases, the medication does not reduce the events mainly because these events are not seizures.
If a person does not respond to antiepileptic medications, further investigation may be needed to explore other possible diagnoses. Sometimes a doctor may decide to wait and see if a similar event occurs again before undertaking further testing.
Epilepsy Action supports children and adults with epilepsy and seizure disorders across Australia. For more information about our services call 1300 EPILEPSY (37 45 37) or visit www.epilepsy.org.au