Juvenile Absence Epilepsy

Juvenile absence epilepsy is a type of epilepsy that typically begins during the teenage years, characterized by brief staring spells and a high likelihood of experiencing full-body seizures that require lifelong management.

Table of contents

• What is Juvenile Absence Epilepsy?
• Medical Classification Codes
• Who Gets Juvenile Absence Epilepsy?
• What Causes This Condition?
• Signs and Symptoms
• How is it Diagnosed?
• Treatment Options
• What to Expect Long-term
• Related Conditions

What is Juvenile Absence Epilepsy?

Juvenile absence epilepsy is a recognized form of idiopathic generalized epilepsy, which means it is a type of epilepsy that affects the whole brain and has no clear underlying cause. This condition is officially recognized by the International League Against Epilepsy.^[1] It typically starts in adolescence around the time of puberty and is characterized by two main types of seizures: absence seizures and generalized tonic-clonic seizures. Some patients may also experience sudden, brief muscle jerks called myoclonic jerks.^[1]

Idiopathic generalized epilepsy as a group accounts for about 20 to 40% of all epilepsies. These conditions share common features including the presence of different seizure types and specific electrical patterns in the brain.^[1]

JAE

Medical Classification Codes

G40.3
8A61.31
10085031

Who Gets Juvenile Absence Epilepsy?

Juvenile absence epilepsy typically begins between the ages of 9 and 13 years, though it may start slightly later. The average age when symptoms first appear is around 12.3 years.^[1] Some sources indicate the condition can begin anywhere between 8 and 20 years of age, with symptoms sometimes starting as early as eight years or as late as adolescence.^[4]

The condition is relatively uncommon. Around 2 to 3 out of every 100 children with epilepsy that starts in childhood or adolescence have juvenile absence epilepsy.^[3] Overall, it accounts for approximately 1 to 2% of all childhood epilepsies and about 15% to 20% of cases of idiopathic generalized epilepsy.^[1] The prevalence has been estimated at about 0.1 per 1,000 persons.^[1]

Juvenile absence epilepsy affects males and females in nearly equal numbers.^[1]

What Causes This Condition?

Children with juvenile absence epilepsy are usually otherwise healthy. They typically do not have a history of neurological problems, intelligence difficulties, or developmental delays before the epilepsy begins.^[2]

While the specific genetic cause is not definitively proven, some genetic associations have been found. Research has identified certain variations in genes that may make a person more susceptible to developing juvenile absence epilepsy. These include variations in genes that affect calcium channels (such as CACNA1H and CACNB4), chloride channels (CLCN2), and GABA receptors (GABRA1).^[1][6] These genetic changes contribute to a person’s susceptibility to the condition but are not sufficient to cause epilepsy on their own.^[1]

Some children with juvenile absence epilepsy have a family history of similar seizures. In one study, a family history of epilepsy was reported in about 42% of cases, and parental relationship (consanguinity) was noted in about 40% of cases.^[1] However, for most children, there is no clear genetic link, and the exact cause remains unknown.^[2]

Signs and Symptoms

Absence Seizures

Almost all patients with juvenile absence epilepsy have absence seizures, which are brief periods when the person suddenly stops what they are doing and stares into space. During an absence seizure, the child is not aware of their surroundings and cannot respond to others.^[1]

These seizures typically involve the following features:

• Sudden staring spells where the child appears to be daydreaming or not paying attention^[2]
• The child’s eyes may roll up briefly^[2]
• Quick blinking or small movements of the hands^[2]
• Each seizure episode lasts only a few seconds, typically less than 10 to 15 seconds^[4]
• The child returns to normal right away after the seizure ends^[2]
• The child often does not realize a seizure has happened^[2]

A key distinguishing feature of juvenile absence epilepsy is that these absence seizures occur much less frequently than in a similar condition called childhood absence epilepsy. In juvenile absence epilepsy, seizures typically happen less than once a day, whereas childhood absence epilepsy is characterized by many seizures occurring throughout the day, sometimes hundreds of times.^[1][2]

Generalized Tonic-Clonic Seizures

Between 79% and 95% of patients with juvenile absence epilepsy also experience generalized tonic-clonic seizures, sometimes called “grand mal seizures.”^[1] These are much more dramatic seizures where:

• The child loses consciousness completely^[2]
• Their muscles stiffen^[2]
• They may fall to the floor^[2]
• Their arms and usually legs begin to jerk^[2]
• Sometimes the child loses control of their bladder or bowel^[2]

This type of seizure is more common in juvenile absence epilepsy than in childhood absence epilepsy, where it occurs in up to 40% of cases.^[4]

Myoclonic Jerks

Between 21% and 39% of patients experience myoclonic jerks, which are sudden, brief, involuntary jerks of a muscle or group of muscles.^[1]

Other Considerations

In rare cases, about 6% of patients may experience a condition called convulsive status epilepticus, where seizures continue for an extended period.^[1] A small number of children may also have episodes of “absence status epilepticus,” where an absence seizure lasts for several hours or even a day or more. This is a medical emergency that requires rescue medication to stop the seizure.^[2]

How is it Diagnosed?

Diagnosis of juvenile absence epilepsy relies on a combination of the clinical features described by the patient and family, along with specific test results.^[6]

Electroencephalogram (EEG)

The key diagnostic tool is an electroencephalogram or EEG, which is a test that records the electrical activity of the brain. During the EEG, the patient is monitored while both awake and during sleep. The test displays a pattern of generalized 3 to 4 Hz spike-and-slow-wave complexes, which is highly characteristic of absence seizures.^[6] This electrical pattern differs from the normal brain wave pattern and helps confirm the diagnosis.

Distinguishing from Childhood Absence Epilepsy

When absence seizures begin around age 10 or later, it can be difficult to determine whether the cause is childhood absence epilepsy or juvenile absence epilepsy. The main way to distinguish between them is the frequency of the seizures. If the child has many seizures every day, the diagnosis is more likely to be childhood absence epilepsy. If seizures occur less frequently, juvenile absence epilepsy is more likely.^[2]

Treatment Options

The goal of treatment is to control seizures and allow the person to live as normal a life as possible. Treatment typically involves antiepileptic medications, also called anti-seizure medicines.

First-Line Medications

The primary medications used to treat juvenile absence epilepsy are:

• Valproic acid (also called valproate or VPA): This is one of the antiepileptic drugs of choice for juvenile absence epilepsy.^[6]
• Lamotrigine (LTG): This medication is also effective for many patients. It can be used as a first-line treatment or added to valproic acid if seizure control is not complete.^[6]
• Ethosuximide: This medication can be beneficial for absence seizures and may be added to valproic acid if needed.^[6]

The healthcare professional usually starts with the lowest possible dose of medication and then increases it as needed to control the seizures.^[2]

Treatment Response

The outlook for treatment is generally favorable. Most patients with juvenile absence epilepsy respond well to medication, and seizure freedom can be achieved with antiepileptic medication in about 62% to 84% of all patients.^[6] About 62% of patients go into remission.^[4]

Important Considerations

It is important to note that some patients may be more challenging to treat, and not everyone achieves complete seizure control. The occurrence of generalized tonic-clonic seizures is associated with a worse outlook.^[6]

What to Expect Long-term

The long-term outlook for juvenile absence epilepsy differs from childhood absence epilepsy in important ways. Most children with childhood absence epilepsy will ultimately reach an age when their absence seizures stop, typically by adolescence or early adulthood. In contrast, people with juvenile absence epilepsy may need to continue treatment into adulthood and often require lifelong anti-seizure medication.^[4]

Seizures in juvenile absence epilepsy are likely to continue into adulthood, which means ongoing treatment and monitoring are usually necessary.^[2] However, with appropriate medication, many people can achieve good seizure control and live relatively normal lives.

Development and cognitive abilities generally remain normal in children with juvenile absence epilepsy. However, uncontrolled absence seizures may have an impact on the ability to learn at school.^[6] Higher rates of inattention are seen in children with absence epilepsy.^[4]

Related Conditions

Juvenile absence epilepsy belongs to a larger group of conditions called idiopathic generalized epilepsies. Other related conditions in this group include:

• Childhood absence epilepsy
• Juvenile myoclonic epilepsy
• Epilepsy with generalized tonic-clonic seizures alone^[1]

Besides juvenile absence epilepsy and childhood absence epilepsy, absence seizures can also occur in other epilepsy conditions, including:

• Jeavons syndrome (eyelid myoclonia with or without absence seizures)
• Myoclonic absence epilepsy
• Lennox-Gastaut syndrome
• Dravet syndrome
• Doose syndrome (epilepsy with myoclonic-atonic seizures)^[4]