The symptom domains are social communication and restricted, repetitive behaviors, with the option of a separate severity - the negative impact of the symptoms on the individual - being specified for each domain, rather than an overall severity. Prior to the DSM-5, the DSM separated social deficits and communication deficits into two domains. Further, the DSM-5 changed to an onset age in the early developmental period, with a note that symptoms may manifest later when social demands exceed capabilities, rather than the previous, more restricted 3 years of age. These changes continue in the DSM-5-TR. Features and characteristics
For many autistic individuals, characteristics first appear during infancy or childhood and generally follow a steady course without remission (different developmental timelines described in more detail below).
Due to research and advances in antiepileptic medication, individuals with ULD can live up to 60 years of age. Nevertheless, severe myoclonus can lead to injury by falling and becoming reliant on a wheelchair. Research
Because PME is so rare it is hard to do studies specifically double blind studies used to test different antiepileptic drugs. The wide range of symptoms including the differing EEG makes studying the effects of the AEDs difficult. In ULD, oligonucleotide therapeutic strategies have been used to replace gene effects while in Sialidosis enzyme replacement therapy has been studied in mouse models. In Laforas disease metformin has been approved for treatment by the European commission. In MERRF bacterial proteins have been identified in treatment in mitochondrial diseases but further studies are needed. History
The first instance where myoclonus and its relationship to epilepsy was in 1822 by Prichard. Lundborg was the first to name progressive myoclonus epilepsy in 1903 due to his study of several Swedish families as well as research done by Heinrich Unverricht in 1891. However, ULD was not recognized as a disease until a century later due to the rarity of the disease. In 1911, Lafora identified Lafora bodies but believed to be part of ULD. Laforas genetics was not described until 1995. Specific disorders
Several conditions can cause progressive myoclonic epilepsy.