Infantile Spasms (West Syndrome):

• Are brief contractions of the neck, trunk, arm, and leg muscles that last 2-10 seconds
• Are NOT seizures, but 86% of children with infantile spasms go on to develop a seizure disorder before 1 year of age
• Usually occur as the child is going to sleep or waking up
• Most commonly seen between 3 and 8 months of age
• Often mistakenly diagnosed as colic
• Poor prognosis as infantile spasms usually indicate an underlying genetic, metabolic, or developmental abnormality

References

Nelson's Essentials of Pediatrics, 5th Edition.