syndrome SCN8A-related epilepsy with encephalopathy true SCN8A-Related Epilepsy syndromes Class SCN8A-related epilepsy with encephalopathy is a condition characterized by recurrent seizures (epilepsy), abnormal brain function (encephalopathy), and intellectual disability. The signs and symptoms of this condition typically begin in infancy.The seizures in SCN8A-related epilepsy with encephalopathy include involuntary muscle contractions that occur before age 1 (infantile spasms), partial or complete loss of consciousness (absence seizures), involuntary muscle twitches (myoclonic seizures), or loss of consciousness with muscle rigidity and convulsions (tonic-clonic seizures). Most people with SCN8A-related epilepsy with encephalopathy have more than one type of seizure. https://www.ncbi.nlm.nih.gov/pubmed/25568300