Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
If prompt community assessment is not available, attend an emergency department.
Call emergency services if:
Contact a medical professional urgently the same day if a baby has repeated, similar crunching, stiffening, head-dropping, or arm-throwing movements.
This remains urgent even if the baby seems well between episodes.
Also seek urgent assessment if a child with known infantile spasms develops new seizure movements, begins having clusters again, loses skills, becomes much less responsive, or has concerning treatment side effects.
Routine questions about development, sleep, therapy, or planned monitoring can usually wait for the child’s regular follow-up appointment unless there is a sudden change.
The article also says
During a seizure, place the child on a safe surface and protect them from injury.
Do not restrain their movements or put anything in their mouth.
Follow any individual seizure plan already provided.
Every sign above is quoted from the sofidex article on Infantile spasms. If you are not sure, err upward — it is always reasonable to be checked.