A rare, genetic neurological disorder characterized by the presence of diffuse pachygyria and arachnoid cysts, psychomotor developmental delay and intellectual disability. Seizures (absence, atonic and generalized tonic-clonic) and, on occasion, headache are also associated. The disease is pachygyria-intellectual disability-epilepsy syndrome (Monarch Disease Ontology term MONDO_0010840). Also known as: Kuzniecky syndrome.