INFANTILE EPILEPTIC SPASMS SYNDROME (IESS)

	Mandatory	Alerts	Exclusionary
Seizures	Epileptic spasms
EEG	Hypsarrhythmia or focal or multifocal epileptiform abnormality	Normal interictal EEG Suppression-burst pattern	Normal EEG during a clinical event suspected to be an epileptic spasm
Age at onset	1-24 months	1-2 months
Comorbidity	Development plateauing or regression after spasm onset
Are MRI or ictal EEG required for diagnosis? An MRI is not required for diagnosis but is highly recommended to evaluate for a structural causes. An ictal EEG is not required for diagnosis, unless mandatory EEG criteria are not present, when an ictal EEG recording is required.
Syndrome in evolution: infants with certain structural brain abnormalities or genetic conditions with abnormal EEG (background slowing and/or multifocal epileptiform abnormality) are at risk of evolving to this syndrome, however this syndrome cannot be diagnosed unless the mandatory seizure type (epileptic spasms) occurs
Syndrome without laboratory confirmation: in resource-limited regions, this syndrome can be diagnosed without EEG if clusters of epileptic spasms are witnessed by an experienced clinician (directly or on video) and other mandatory criteria are met

NOTE Alert criteria are absent in the vast majority of patients with the syndrome, but rarely can be seen. Their presence should result in caution in diagnosing the syndrome and consideration of other conditions