A syndrome that has a characteristic cluster of clinical features and/or lectroencephalographic (EEG) findings that reflect underlying epileptic activity. It is often associated with a range of other health issues, including cognitive impairment, intellectual disability, physical gross motor and fine motor delays, speech and language deficits, and impacts to other bodily functions and may be supported by specific etiological findings—such as structural, genetic, metabolic, immune, or infectious causes or have an unknown etiology.