There are many different types of childhood epilepsy syndrome, six of which are outlined below. When diagnosing an epilepsy syndrome, factors such as the type of seizure the child is having, their age at seizure onset, their gender and whether or not they have learning difficulties are very important. Once a doctor has diagnosed a particular syndrome, he/she will be able to consider the best course of treatment and the likely prognosis.
Rolandic epilepsy is the most common of the childhood focal epilepsy syndromes, and it accounts for about 15-20% of childhood epilepsies. It is characterised by focal seizures that usually occur during sleep or just before wakening, and involve the face, mouth and speech organs (although in some cases seizures may be more generalised).
Rolandic epilepsy most commonly occurs between the ages of six and eight years, but the cause, although suspected to be genetic, is not fully established. Most children grow out of the condition when they reach adulthood, and because seizures occur at night and learning is not usually impaired, neurologists often refrain from treating it with anti-epileptic drugs (they often referred to it as ‘benign’). There is increasing evidence, however, that Rolandic epilepsy can affect attention, learning and neurological development; and this must be taken to consideration by neurologists when making treatment (or non-treatment) plans.
Epilepsy Research UK is currently funding a study into the complications associated with Rolandic epilepsy at King’s college London. For more information please click here.
West’s syndrome (infantile spasms)
West’s syndrome is a disorder of the brain that occurs in approximately one in every 5,000 babies. It is characterised by infantile spasms (a form of epilepsy that usually develops before the age of one, often at about six months), a specific EEG pattern, developmental regression and, often, learning/physical disabilities. Many of the conditions that cause West’s syndrome are genetically inherited, but this is not always the case; so it is very important to establish the exact cause in each child.
Treatments for West’s syndrome include anti-epileptic drugs and oral steroids. Children’s responses to these medications are highly variable, however, and cannot be predicted. In cases of drug resistance, epilepsy surgery may be considered.
Rett syndrome is a neurodevelopmenal disorder that affects girls almost exclusively. It is characterised by normal early growth and development, followed by a slowing of development, loss of purposeful use of the hands, distinctive hand movements, slowed brain and head growth, problems with walking, seizures, and intellectual disability.
It is estimated that one in 10,000 to 15,000 female babies will be affected by Rett Syndrome, sometimes as early as six months of age. Nearly all cases genetic, but it is thought that 99% of genetic cases are due to spontaneous mutations, not defects inherited from the parents.
There is no cure for Rett Syndrome and most treatments are symptomatic, for example anti-epileptic drugs for seizures and other medications for breathing/movement irregularities.
Angelman syndrome is a genetic neurological disorder that occurs in approximately one in every 25,000 children. It is characterized by intellectual and developmental delay, sleep disturbance, seizures, jerky movements (especially hand-flapping) and frequent laughter or smiling. It is usually diagnosed between the ages of three and seven years, when the clinical symptoms become apparent, but developmental delay may begin as early as six months.
There is no specific therapy for Angelman syndrome, but treatment for seizures is usually needed. Physical and occupational therapies, communication therapy and behavioral therapies are important in allowing individuals with Angelman syndrome to reach their maximum developmental potential.
Dravet syndrome affects approximately one in 40,000 to one in 20,000 children, but the incidence may be found to be greater as genetic research progresses (as is the case for many genetic conditions). Its course varies greatly, but seizures typically begin during the first year of life and neurological development is usually normal prior to their onset.
In most cases, the first seizures occur with fever and are generalised tonic-clonic or one-sided convulsions. They are usually prolonged (longer than five minutes) and may require emergency intervention. Seizures usually increase in frequency over the following weeks or months, and they begin to occur without fever. Additional seizure types appear later.
During the second to fourth year of life, varying degrees of developmental delay typically become apparent. Some seizure types tend to disappear, but convulsive seizures typically persist, often occurring in sleep.
Treatment for Dravet syndrome mainly involves anti-epileptic drugs to control seizures, although the response is variable and seizures often persist in spite of medication. A ketogenic diet may be beneficial in some cases.
Children with Dravet syndrome are at an increased risk of sudden unexpected death in epilepsy (SUDEP) than those with other types of epilepsy, although they have about an 85% chance of surviving into adulthood.
Please visit www.dravet.org.uk for more information.
Lennox-Gastaut syndrome is a ‘difficult-to-treat’ form of childhood-onset epilepsy that affects approximately one in 50,000 children, and usually appears between the second and sixth years of life. It is characterised by frequent seizures of different types and is often accompanied by mental retardation, psychological and behavioral problems. In up to a third of cases, no cause can be found.
Lennox-Gastaut is notoriously resistant to anti-epileptic medication and often multiple drugs, in high doses, must be prescribed. If there is still no improvement, alternative treatments such as the ketogenic diet or epilepsy surgery may be considered.
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