<unk>  (OS), also known as early infantile epileptic encephalopathy (EIEE) is a progressive epileptic encephalopathy. The<unk>  is outwardly characterized by tonic spasms and partial seizures within the first few months of life, and receives its more elaborate name from the pattern of burst activity on an electroencephalogram (EEG). It is an extremely debilitating progressive neurological disorder, involving intractable seizures and severe intellectual disabilities. No single cause has been identified, although in many cases structural brain damage is present.
Ohtahara syndrome
Pallister–Killian syndrome
Cohen syndrome
Cohen-Gibson syndrome
Berdon syndrome
Scheie syndrome
Gleich's syndrome
Christianson syndrome