Unverricht-Lundborg Disease

8th April 2021

Unverricht-Lundborg Disease (ULD) is a very rare epilepsy syndrome that research indicates only affects between 1 to 4 children in every 100,000. Most children with ULD will develop tit between the ages of 6 and 16. 

ULD is part of a group of epilepsy syndromes known as ‘progressive myoclonic epilepsies’ and is due to an abnormality in the cerebellum part of the brain. The main purpose of the cerebellum is to control movement and motor activity. This part of the brain sends electrical impulses to the muscles in the body allowing us to move smoothly and instinctively. Children with ULD will often experience coordination issues because of this, medically known as ‘ataxia’. 

ULD is inherited through a genetic disposition, which means it often runs in families. It’s caused by a mutation of the CSTB gene, which is responsible for the body’s production of a protein known as cystatin B, which is important for brain function.  

Other names for Unverricht-Lundborg Disease include:

• Baltic myoclonus

• A progressive myoclonic epilepsy

• Progressive myoclonic epilepsy Type 1

• Mediterranean myoclonic epilepsy

• EPM1 

Symptoms 

Around 50% of children with ULD will experience tonic-clonic seizures, which will often commence when the child is asleep. The other 50% will have myoclonic seizures. All children with ULD will have myoclonus, a brief jerk. This can happen in one or more limbs or in some cases the entire body (generalised). Myoclonus usually ceases whilst the child is asleep or at rest. 

For more information on seizure types click here. 

Children with ULD will also have poor coordination, also known as ataxia. This means the child will be unable to walk in straight lines or perform relatively simple tasks like feeding themselves or getting dressed. As a result, they may require support for daily activities. 

Diagnosis

Unverricht-Lundborg Disease (ULD) can often be misdiagnosed as juvenile myoclonic epilepsy (JME). A diagnosis of ULD is often made on clinical history signs and symptoms and the age at which seizures begin. 

An electroencephalogram (EEG) can assist to make a diagnosis of ULD and will observe spikes in the vertex of the brain during the child’s sleeping hours, this is also known as Rapid Eye Movement (REM) sleep. Abnormalities may also be detected during the hours the child is awake and display polyspike discharges and photosensitivity. 

A blood test may be required to detect a genetic abnormality which has only recently been discovered and could contribute to the diagnosis of ULD. 

Treatment 

With Unverricht-Lundborg Disease (ULD), the first step will be to trial the use of anti-seizure medications (ASDs). This includes sodium valproate, clonazepam, levetiracetam and topiramate. 

There are medications which should be avoided with this syndrome as they can exacerbate the ataxia and myoclonus. These include phenytoin, carbamazepine and vigabatrin. 

Prognosis 

Due to the abnormality in the cerebellum, the child will often experience lifelong difficulties with coordination and balance. This can affect the quality of life and means they are unable to perform daily activities, such as washing, dressing and eating. For this reason, the majority of people with ULD will need daily support.

Seizures will typically become less frequent as the child becomes older and may even stop altogether in the late teenage years. Unfortunately, the myoclonus may become more frequent. 

The syndrome is not life-threatening when treated and intellectual difficulties are not common with the syndrome. Children may experience a slurring of speech during their teenage years and beyond, but other senses are not impaired. 

National Epilepsy Training can help

For more information on Unverricht-Lundborg Disease (ULD), or to enquire about our care or training services, please call 01706 373075 or email admin@nationalepilepsytraining.co.uk