A group of syndromes featuring a combination of myoclonic and tonic-clonic seizures. Unsteadiness, muscle rigidity, and mental deterioration are often also present.
Progressive myoclonus eplilepsy or Unverricht-Lundborg disease is a recessively inherited epileptic disorder of young children and adults due to misfunction of cystatin B. Detailed pathogenetic mechanisms are still unknown. First clinical symptoms occur after a normal infancy and early childhood at the age of 6 to 15 years presenting with epileptic seizures followed soon later by myoclonic jerks. Attacks are easily provoked by varied stimuli, particularly after waking in the morning. The course of the disease is progressive and without proper treatment slowly leads to decline of mental and motor functions. Spike-and-wave pattern is typical finding of EEG recording.