Epilepsy

Description

Outlook

Acute Repetitive Seizures. Some patients occasionally experience seizures called acute repetitive, serial, or cluster seizures; these are two or more seizures occurring over minutes to hours separated by periods of consciousness. Left untreated, they can develop into status epilepticus, a very serious condition.

Status Epilepticus. Status epilepticus is often defined as recurrent convulsions that last for more than 20 minutes and are interrupted by only brief periods of partial relief. Some experts believe these criteria are too strict and that the condition should be diagnosed if seizures last at least five minutes or more, or when the patient does not fully recover consciousness between two or more seizures. Although any type of seizure can be sustained or recurrent, the most serious form of status epilepticus is the generalized convulsive or tonic-clonic type. In more than a third of cases, status epilepticus occurs with the first seizure.

The trigger is often unknown, but can include the following:

• Failure to take anti-epileptic medications (comprising about a third of these events).
• Abrupt withdrawal of certain anti-epileptic drugs, particularly barbiturates and benzodiazepines.
• High fever.
• Poisoning.
• Electrolyte imbalances (imbalance in calcium, sodium, and potassium).
• Cardiac arrest.
• Stroke. In one study, about 9% of stroke patients with seizures had status epilepticus, which was associated with higher disability after the stroke, particularly if these severe seizures occurred within a week of the stroke.
• Low blood sugar in people with diabetes.

Status epilepticus (SE) is a serious condition that can lead to chronic epilepsy and can be life threatening. It occurs in 100,000 to 150,000 people in the US each year, over half of whom are children. Permanent brain damage or death can result if the seizure is not treated effectively; the longer the seizure lasts, the greater the danger. Mortality rates from this condition are about 10%. (This high mortality rate is most likely due to a high incidence of myoclonic SEs in elderly adults after cardiac arrest. One study reported much lower mortality rates from SE when cardiac arrest in elderly epilepsy patients is excluded.)

Survival Rates and General Outlook for Patients with Epilepsy

Chances for Becoming Seizure Free. Most patients can control their seizures with a single drug and stop drug treatment completely after two seizureless years. In fact, the sooner patients achieve remission using an anti-epileptic drug (AED), the better their chances for remaining seizure-free in the future. If epilepsy is not effectively treated and the patient has continuing seizures, changes in the neurons may eventually cause intractable (also known as refractive) epilepsy, that is, epilepsy that is hard to control. Early treatment, then, is extremely important.

Effects of Epileptic Seizures on the Brain. Some studies have reported changes in brain structures in epileptic patients, but it is unclear if such changes are a cause or result of seizures. A reassuring 2003 study found no indication that seizures cause any progressive abnormalities in the brain.

Survival Rates. Epileptic patients who are cured have a normal lifespan. Their long-term survival rates are lower than average, however, if medications or surgery fail to stop the seizures. The lower survival rate is partly due to a higher-than-average risk for death due to accidents and suicide. The specific cause of the seizure may also contribute to fatalities.

There is a very low risk for sudden death in patients with epilepsy. Although the causes of such events are not fully known, experts suspect heart arrhythmias in many cases. There is some evidence, in fact, that a malfunction in the autonomic nervous system (which controls heart rate) may be responsible for some of these deaths. Some researchers believe that temporal lobe surgery in appropriate patients may reduce the risk. Drugs that block arrhythmias may also be helpful in reducing this risk.

Effects of Epilepsy in Children

Chance for Recurrence After a First Seizure. According to one 2000 study, about 64% children with one seizure unrelated to fevers have another one, and 74% who have more than one seizure are likely to have more seizures. Researchers are trying to find ways of predicting which children have the best chances to become seizure free and which ones will not. Studies suggest that it is how frequent early seizures occur, not their total number or type, that determines whether a child will develop intractable epilepsy.

Long-Term General Effects. In general, the long-term effects of seizures vary widely depending on the seizure's cause:

• Febrile (Fever-Related) Seizures. Children with febrile seizures rarely have any long-term effects. In very rare cases, children experience severe fever-related seizures known as complex febrile convulsions. In such cases, there is a risk for brain injury that may lead to temporal lobe epilepsy, but this is very small. Such seizures last over 15 minutes, occur more than once within 24 hours, and may affect only one side of the body.
• Idiopathic Epilepsy (Seizures of Unknown Causes). The long-term outlook for children with epilepsy of unknown causes is very favorable. One study reported that between 68% and 92% of such individuals were seizure-free after 20 years. In addition, a 2000 study reported that they had a survival rate no different from children without these seizures.
• Epilepsy Caused by a Pre-Existing Condition. Children with epilepsy that is a result of a specific condition (for example, a head injury or neurologic disorder) have higher mortality rates than the normal population, but their lower survival rates are most often due to the underlying condition not the epilepsy itself.

Side Effects of Medications and Withdrawal from Them. The agents used for epilepsy can have distressing short- and long-term effects. Eventually, many children with epilepsy can go off medication. Children who tend to relapse after withdrawal from treatment are those with the following conditions or situations:

• A family history of epilepsy.
• Require multiple medications to control seizures.
• Abnormal EEG readings after treatment has started.
• Partial seizures.

Effect on Memory and Learning. The studies on the effects of seizures on memory and learning vary widely and depend on many factors. Some results include the following:

• A 2001 study reported greater mental flexibility and memory capacity in some children with a history of febrile seizures compared to peers who did not have these seizures. Children with a history of febrile seizures before age one, however, were at higher risk for some learning deficits.
• A number of studies have demonstrated no diminished intelligence in patients with epilepsy that occurs in the left temporal lobe (the left side of the brain where most complex partial types occur). A 2000 study suggested, however, that it may affect long-term memory. Patients with seizures originating on the left side of the brain may also have less well-developed language skills than those with right-side epilepsy.
• A 2001 study suggested that children with generalized epilepsy who have petit mal (absence) seizures tend to retain their language skills and verbal memory, but some may have poorer testing scores, problems with nonverbal memory, and a slower recall of events.

In general, the earlier a child has seizures and the more extensive the area of the brain affected, the poorer the outcome. And, children with seizures that are not well-controlled are at higher risk for intellectual decline.

Social and Behavioral Consequences. Studies have noted that children with epilepsy perform worse on behavioral tests than do other children. In a well-conducted 2000 study, girls with severe epilepsy had the highest rate of behavioral problems (and they worsened over time) compared to boys and girls with mild or moderate epilepsy and all children with asthma, another chronic illness. In another study, although there were no differences in intelligence, adults with previous epilepsy (even if they no longer had seizures) were less likely to attain higher-education degrees. They were slightly more likely to be unemployed, unmarried, and childless compared to the general population.

Effects of Epilepsy in Adults

Chance for Recurrence. Adults whose first episode occurs when they are over 59 years of age have a higher risk for recurring seizures than do younger adults. Some studies have indicated that recurrence is least likely in adults with the following combination of factors:

• A primary generalized seizure.
• A seizure-free period of between two and five years.
• A normal EEG reading.
• Only a single-drug treatment.

In one study of adult-onset epilepsy, it was discovered that after one year of treatment, 70% of patients experienced complete control of their seizures, 14% had occasional seizures, and 16% were unable to control the seizures.

Effect on Mental Functioning in Adults. The effects of adult epilepsy on mental functioning are not clear. In fact, in a 2001 study, IQ scores increased in adults with recurrent seizures during the trial period. More research is needed in this area, as results have been contradictory. For instance, one 2000 study yielded the opposite result, reporting that intelligence scores start declining with long duration of adult epilepsy.

Overall Physical Effects. In a major 2000 survey, 46% of the respondents with epilepsy described their overall health as "fair" or "poor" compared to 18.5% of those who did not have epilepsy. People with epilepsy also report a higher frequency of pain, depression, anxiety, and sleep problems. In fact, their overall health state is comparable to people with other chronic diseases, including arthritis, heart problems, diabetes, and cancer. Most of treatments themselves can have considerable physical effects, such osteoporosis and weight changes.

Emotional Consequence. About 25% to 75% of adults with epilepsy show signs of depression. They also have a higher than average risk for suicide. The most common emotional responses are the following:

• Fear of the unexpected seizure.
• Acute humiliation after a seizure, particularly if incontinence occurs.
• Feelings of alienation at work and in social situations.

Emotional difficulties increase if epilepsy becomes chronic. In one study, the intensity of the negative emotional response was directly related to the intensity and frequency of the attacks.

Effect on Sexual and Reproductive Health

Effects on Sexual Function. There have been studies suggesting that up to two-thirds of patients with epilepsy experience sexual disturbances, including impotence in men. There are various reasons for this:

• Epilepsy in childhood may cause disturbances in hormones regulating puberty.
• Persistent seizures in adults may be associated with other hormonal and neurologic changes that contribute to sexual dysfunction.
• Negative emotions due to epilepsy can reduce sexual drive.
• Medications may be responsible for many of these cases, although newer agents may reduce this problem.

Effects on Female Fertility and Pregnancy. Epilepsy and its treatments can have adverse effects on female fertility and pregnancy.

Injuries and Accidents

Injuries from Falls. Because many people with seizures fall, injuries are common. Although such injuries are usually minor, people with epilepsy have a higher incidence of fractures than those without the disorder. (Epilepsy patients who take the drug phenytoin have an even higher risk, since the drug can cause osteoporosis.)

Driving and the Risk for Accidents. Being unable to drive is an extremely distressing and severe component of the disorder. Drivers with well-controlled epilepsy are not at a high or unacceptable risk for automobile accidents. Uncontrolled epilepsy, however, poses a high risk. Needless to say, seizures can be very dangerous if they occur while a person is driving. Studies have reported that over 25% of people with uncontrolled epilepsy who drove had had an accident at some time because of a seizure. In one study, over half of these accidents had resulted in injuries to the patients or others. Unfortunately, in spite of these events, 30% of these patients had driven within the past year, and most had driven at least once a week.

Four factors help predict who may safely drive:

• A long duration between seizures. In one 1999 study, being seizure-free for six months reduced the risk for accidents by 85%, and being seizure-free for a year lowered the risk by 93%. State laws restricting driving in people with seizures vary from requiring seizure-free periods of three months (which is too short for protection) to 18 months.
• Having few seizure-related accidents.
• Having a reliable pre-seizure warning sign, such as an aura.
• Recently having reduced or changed medications.

Accidents while Swimming. Swimming poses another danger for people with epilepsy, particularly those with tonic seizures, which can cause the diaphragm to expel air quite suddenly. People with epilepsy who swim should do so under the following conditions:

• Always with a knowledgeable, competent, and experienced companion or supervisor; one-to-one is best.
• Avoid deep and cloudy water. A clear swimming pool is best.