Epilepsy with myoclonic absences

23rd April 2019

This rare form of epilepsy is slightly more prevalent in males than in females. Epilepsy with myoclonic absences is a syndrome that has no known cause, however, it’s believed that it is likely genetic as 25 out of 100 children with this particular syndrome also have a relative who also has epilepsy. Myoclonic absences are also commonly seen in children with brain abnormalities and genetic disorders, but may also be present in children with no clear cause.

What are the symptoms of epilepsy with myoclonic seizures

There are a number of symptoms that are associated with this syndrome. Perhaps the most typical will be a loss of awareness in surroundings, as is suggested by the name ‘absence’. The severity of this loss of awareness can vary from child to child. This is often accompanied by rhythmic jerking and stiffening of the arms, causing them to become raised above the head. Facial jerking around the chin and mouth is also a common symptom.

Myoclonic absences will normally last a relatively short amount of time, between 5 and 10 seconds, although they can last longer. Seizures are most common when the child is tired or has recently woken up.

Diagnosis for epilepsy with myoclonic seizures

The first stage of diagnosis will normally require an eye witness account of a seizure that will enable the doctor to identify its type. If possible, a video would be even more helpful and enable the doctor to make a diagnosis. It may be necessary for the doctor to provoke a seizure in order to ensure an accurate diagnosis, this is often done by asking the child to hyperventilate for up to 4 minutes.

An electroencephalogram (EEG) test will likely be ordered as well, which should be able to capture the absence and record information that should enable a diagnosis. It’s also possible that a blood test and brain scan may be ordered to establish rare genetic disorders that may be the underlying cause, such as GLUT1 deficiency and Ring Chromosome 20, which are both incredibly rare.

Treatment for epilepsy with myoclonic seizures

Treatment for this particular syndrome can be difficult as it can often be resistant to epilepsy medications (AEDs). However, it’s likely that these will be tried first. Common AEDs for this syndrome include sodium valproate (Epilim), ethosuximide (Zarontin) and lamotrigine (Lamictal) or a combination of different AEDs.

The ketogenic diet has shown to be an effective treatment in some children and may be worth considering. However, it’s important that this is done under the supervision of a specialist dietician. Read more about the ketogenic diet here in one of our other blog posts. 

Prognosis

The outlook for epilepsy with myoclonic absences can vary considerably from child to child. Unfortunately, approximately 50% will continue to have seizures into adulthood. Those who don’t respond to treatment are the most likely to develop into other types of seizures. Evidence for learning difficulties and behavioural issues as a result of this syndrome are limited but do exist.

National Epilepsy Training can help

For more advice on epilepsy with myoclonic absences or to enquire about our training and care services, please call us on 01706 373075 or email admin@nationalepilepsytraining.co.uk.