KCNT1 and Hypsarrhythmia: Generalized electrodecrement and hypsarrhythmia, more classically associated with infantile spasms, have been previously described in EIMFS.2,4,9,10,31 EEG suppression, classically seen in Ohtahara syndrome,37 has been only rarely described in EIMFS.4,9 Extensive diagnostic investigations undertaken in patients with KCNT1 mutations were unyielding other than abnormal respiratory chain enzyme analysis of muscle tissue in 2 patients.