Parameters:
(1) presence of infantile spasms
(2) epileptiform on EEG
(3) age of the patient
(4) interictal EEG consistent with infantile spasms
(5) pattern of spasms
(6) hypsarrhythmia on EEG, with or without atypical features
Features of West syndrome:
(1) presence of infantile spasms
(2) epileptiform on EEG
(3) age of the patient at onset < 2 years
(4) interictal EEG consistent with infantile spasms
(5) spasms occur in clusters
(6) hypsarrhythmia on EEG
Features of infantile spasms without hypsarrhythmia:
(1) presence of infantile spasms
(2) epileptiform on EEG
(3) age of the patient at onset < 2 years
(4) interictal EEG consistent with infantile spasms
(5) spasms occur in clusters
(6) no hypsarrhythmia on EEG
Features of infantile spasms single spasm variant (ISSV) with hypsarrhythmia:
(1) presence of infantile spasms
(2) epileptiform on EEG
(3) age of the patient at onset < 2 years
(4) interictal EEG consistent with infantile spasms
(5) spasms do not occur in clusters
(6) hypsarrhythmia on EEG
Features of infantile spasms single spasm variant (ISSV) without hypsarrhythmia:
(1) presence of infantile spasms
(2) epileptiform on EEG
(3) age of the patient at onset < 2 years
(4) interictal EEG consistent with infantile spasms
(5) spasms do not occur in clusters
(6) no hypsarrhythmia on EEG
The absence of infantile spasms, nonepileptiform EEG, older age at onset, or an interictal EEG not indicative of infantile spasms suggest another diagnosis.
