Unverricht-Lundborg disease (ULD) is the leading cause of progressive myoclonus epilepsy (characterized by brief, jerking spasms of a muscle or muscle group) worldwide.
The prevalence of Unverricht-Lundborg disease is unknown. However, in Finland, nearly four out of every one hundred thousand suffer from Unverricht-Lundborg disease.
A change in a gene called the CSTB gene is the cause of ULD. The CSTB gene tells the body how to make the protein cystatin B. This protein is vital to the way the brain works, especially the part of the brain called the cerebellum. In ULD, the different symptoms are caused by an abnormal protein called cystatin B.
Doctors will perform history taking, physical examination, and a focus on neurological physical exam to elicit the expected motor deficits.
Genetic testing is one of the most important tests to check if the patient has mutations in the CSTB gene.
EEG will also be ordered due to epilepsy, as the severity needs to be assessed.
Magnetic resonance imaging (MRI) as patients who suffer from ULD was found to have atrophy in areas of the brain such as the cortical motor areas, the pons, the medulla, and the cerebellar hemispheres.
Treatment
Although no known treatment can guarantee a full recovery, many symptoms can be managed. The seizures and movement myoclonus caused by epilepsy can be managed with medication. Among these drugs are sodium valproate (Epilim), clonazepam (Rivotril), levetiracetam (Keppra), and topiramate (Topamax).
Young adults and adolescents with severe action myoclonus may benefit from piracetam, a separate class of medication.
Lastly, the ketogenic diet has shown promise, particularly in reducing the frequency of seizures (both tonic-clonic and myoclonic).
Unfortunately, ULD is unpreventable; however, symptom control is the best management that doctors and experts offer presently.
References
Lehesjoki AE, Gardiner M. Progressive myoclonus epilepsy: Unverricht-Lundborg disease and Neuronal ceroid lipofuscinoses. In: Noebels JL, Avoli M, Rogawski MA, et al., editors. Jasper's Basic Mechanisms of the Epilepsies [Internet]. 4th edition. Bethesda (MD): National Center for Biotechnology Information (US); 2012. Available from: https://www.ncbi.nlm.nih.gov/books/NBK98154/
National Institutes of Health (2021). Unverricht-Lundborg disease. Retrieved December 27, 2022, from https://rarediseases.info.nih.gov/diseases/3876/unverricht-lundborg-disease/living
National Organization for Rare Diseases (2021). NIH GARD Information: Unverricht-Lundborg disease. Retrieved December 27, 2022, from https://rarediseases.org/gard-rare-disease/unverricht-lundborg-disease/