Benign myoclonic epilepsy in infancy

This is a very rare form of epilepsy which is more common in boys than girls. Seizures begin from four months to three years of age.

Approximately one-third of children who have this condition also have another family member who either has epilepsy or has convulsions when they have a fever (febrile convulsions).

In most cases there is no identifiable cause for this epilepsy.

Symptoms

The seizures themselves are brief and may not initially be noticed. They involve head nodding and usually occur several times a day. They may cause loss of balance but only rarely will the child fall. As the child’s head drops forward onto their body, their arms tend to move upwards and outwards, while their legs may flex. They sometimes roll their eyeballs.

Diagnosis

A full account of the seizures and of what happens during the seizures is essential for the doctor making the diagnosis.

The electroencephalogram (EEG) test which records the electrical activity in the brain shows evidence of abnormal discharges of spikes and waves or polyspikes and waves, particularly as the child is falling asleep. The abnormalities can be made worse by exposure to flashing lights.

Treatment

The seizures virtually always respond to sodium valproate (Epilim).

Prognosis (outlook)

Approximately half the children who have benign myoclonic epilepsy in infancy have normal behaviour and intellectual development later. However, there is some risk of delayed learning. In particular there may be delayed language development. It is not possible to say at an early stage which children will have later difficulties in learning. Some children also have behavioural problems.

Support organisations

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

Epilepsy Action is indebted to Dr Richard Appleton, a Consultant Paediatric Neurologist who specialises in children’s epilepsy, and to Dr Rachel Kneen, Consultant Paediatric Neurologist and Dr Stewart Macleod, Specialist Registrar in paediatric neurology, at Alder Hey at Alder Hey Children’s Hospital, Liverpool, who have kindly prepared the information on this page.

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