EPILEPSY OF INFANCY WITH MIGRATING FOCAL SEIZURES (EIMFS)

	Mandatory	Alerts	Exclusionary
Seizures	Focal/multifocal tonic or clonic seizures with/without subtle behavioural arrest and prominent autonomic features Seizures migrate from one hemisphere or lobe to another clinically Seizure frequency increases rapidly in the first weeks and months often progressing to status epilepticus		Myoclonic seizures
EEG	Migrating ictal EEG pattern (prolonged EEG may be required) Interictal multifocal discharges	Suppression burst pattern prior to medication Single epileptic focus Hypsarrhythmia
Age at onset	<12 months	6-12 months
Development at onset		Prior severe impairment
Neurological exam		Previous significant abnormality on exam
Comorbidity	Development plateaus/regresses with frequent seizures
Imaging			Structural cause for the epilepsy
Course of illness	Developmental impairment	Seizure remission Lack of brain atrophy on imaging
Are MRI or ictal EEG required for diagnosis? An MRI is required for diagnosis to exclude other causes An ictal EEG is not required if clinical seizures are observed with features consistent with seizure migration from one hemisphere or lobe to another, however ictal EEG is strongly recommended to document a migrating pattern
Syndrome without laboratory confirmation: in resource-limited regions, this syndrome can be diagnosed without EEG or MRI if there is clinical observation of seizures with features consistent with migration, and all other mandatory and no exclusionary 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