Generalised epilepsy with febrile seizure plus (GEFS+)

GEFS+ is an unusual epilepsy syndrome in that it describes families who have several members from different generations with epileptic seizures.

In family members with epileptic seizures they almost always start with febrile convulsions (seizures associated with high temperature). Normally febrile convulsions stop after the age of six.
In GEFS+ families, children may go on to have febrile seizures well beyond this age group or develop other seizure types not associated with fever.

Very rarely there may be a family member with a very severe type of epilepsy called Dravet’s syndrome (severe myoclonic epilepsy of infancy or SMEI).

GEFS+ has only recently been described as an epilepsy syndrome in its own right and has caused great interest amongst epilepsy researchers. Some people with GEFS+ are found to have a specific fault in their genes. This may provide some clues to the genetic basis of some forms of epilepsy.

Symptoms

The seizure types in this syndrome vary from person to person and may include the following.

• Febrile seizures (febrile convulsions) – these seizures always occur during a period of illness, for example with a viral infection, and are associated with a high fever. They are usually short generalised tonic-clonic seizures lasting less than five minutes. Sometimes the seizures can last longer and require emergency medical treatment.

The normal age range for this type of seizure is six months to six years. Although most individuals only have a small number of seizures (fewer than five) some children can have frequent febrile seizures throughout early childhood.

• Febrile seizures plus – this is similar to febrile seizures but the person has seizures beyond the normal age range. Again, the seizures are always associated with high fever. The seizures usually stop by the time the child reaches the age of 10 or 12 .
• Afebrile generalised tonic-clonic seizures. Seizures not triggered by illness or high fever.
• Absence seizures – brief (usually lasting less than 30 seconds) seizures where the child becomes vacant, loses awareness of their surroundings environment and stares blankly into the distance. There may be some associated twitching (myoclonia) of the eyelids and mouth. These seizures usually happen daily, sometimes dozens of times a day.
• Myoclonic seizures – sudden, very brief jerks of the limbs (arms and hand more commonly than legs) which can happens singly or sometimes in clusters.
• Atonic seizures (drop attacks) – a sudden loss of posture and muscle tone resulting in the child slumping or falling.
• Focal seizures (partial seizures) – seizures arising from a single area of the brain. The symptoms and signs of a focal seizure depend on the area of the brain the seizure starts in and whether the seizure spreads from that area to involve other areas or the whole brain. Awareness or consciousness may be altered throughout the seizure (simple partial) or may be impaired or lost altogether (complex partial).

In addition to the above, there may be people within GEFS+ families who develop other epilepsy syndromes, specifically myoclonic astatic epilepsy (MAE or Doose syndrome) and Dravet’s syndrome.

The majority of GEFS+ patients have normal intelligence and learning abilities, however those with myoclonic astatic epilepsy and particularly Dravet’s syndrome may have varying degrees of learning difficulties and behavioural problems

Diagnosis

GEFS+ is usually identified when the doctor takes a careful family history from a patient presenting with febrile seizures outside the normal age range. This may involve talking to immediate family members, particularly to grandparents, who may remember their children or nieces and nephews having febrile convulsions or other seizure types as a child.

There have been a number of small genetic abnormalities found in some families with GEFS+. The abnormalities can be found in a simple blood test. However these tests are not routinely available at the moment and are usually only requested as part of a research study.

Treatment

Treatment very much depends on the seizure type or types each person within the family has. For febrile convulsions, regular treatment with anti-epileptic medication is not required. People with generalised tonic-clonic seizures not associated with fever, absence, myoclonic or drop attacks may be treated with medications such as sodium valproate (Epilim), lamotrigine (Lamictal), ethosuximide (Zarontin) and clobazam (Frisium).

In the rare cases where children have more severe forms of epilepsy such as myoclonic astatic epilepsy or Dravet’s syndrome, treatment may be difficult and can require combinations of the above medications to treat seizures. A new drug called stiripentol (Diacomit) may be particularly effective in Dravet’s syndrome, when used in combination with sodium valproate and clobazam.

Prognosis (outlook)

The prognosis depends on the individual child’s seizure types. Simple febrile convulsions usually stop after the age of six. Some people may have febrile seizures past the age of six, usually in decreasing frequency and most stop before the child reaches puberty. With other children, the prognosis is more varied. The majority will have their seizures well controlled with medication and their seizures may stop in late childhood/early teenage years.
However in some cases of myoclonic astatic epilepsy, and in most cases of Dravet’s syndrome, the seizures are difficult to treat, are usually lifelong (although becoming less frequent through adolescence) and are associated with learning and behaviour difficulties.

Support organisations

Contact a Family, 209-211 City Road, London, EC1V 1JN, telephone 0808 808 3555, www.cafamily.org.uk

Because this page is written by an epilepsy healthcare professional and not by Epilepsy Action, it falls outside the requirements of the Information Standard.