Seizure Focal-onset seizure 2008-03-31T05:27:00Z Focal seizures In 2017 the ILAE Commission for Classification and Terminology recommended classifying a seizure as having focal or generalized onset only when there is a high degree of confidence (>80%, arbitrarily chosen to parallel the usual allowable beta error) in the accuracy of this determination; see Dialeptic seizure. HP:0040168 HP:0007359 Seizure affecting one half of brain HP:0002358 SNOMEDCT_US:29753000 UMLS:C0751495 Partial seizures Focal onset seizure Partial seizure Focal seizure A focal-onset seizure is a type of seizure originating within networks limited to one hemisphere. They may be discretely localized or more widely distributed, and may originate in subcortical structures. Focal-onset seizures