Introduction
- Progressive Myoclonus Epilepsy (PME) with onset between late childhood and late adolescence includes several conditions:
- Neuronal ceroid lipofuscinosis
- Type I sialidosis
- Myoclonic epilepsy with ragged red fibers
Unverricht–Lundborg Disease
Clinical Characteristics and Neurophysiology
- Lafora disease
- Unverricht–Lundborg disease (ULD)
EPM1, the ULD Gene
- ULD is an autosomal recessive PME.
- Onset: Between ages 6 and 15 years, following a period of normal development.
- Principal characteristics:
- Stimulus-sensitive myoclonus: Sudden, brief, shocklike muscle contractions interfering with activities like writing, swallowing, speaking, and walking. Can be precipitated by simple intention to move (Harenko 1961, Koskiniemi 1974a, Koskiniemi 1974b, Koskiniemi 1974c).
- Tonic-clonic and myoclonic seizures: Appear early, with other types of seizures potentially presenting later.
Cystatin B and the Cystatin B-Deficient Mouse