Infantile spasms (IS) is a rare seizure disorder that occurs in young children, usually under one year of age. About 400 children a year are diagnosed in the UK. The average age of onset is around four months, but some children may experience spasms as early as one month. A few children may begin as late as two years.
It often has a very subtle appearance so it is difficult for parents to recognise that it is a serious problem. The typical pattern is a sudden bending forward and stiffening of the body, arms and legs. Sometimes, the episodes are different, with the arms and legs being flung outwards (these are called ‘extensor’ spasms). Usually, they affect both sides of the body equally. Typically, each episode lasts just 1 or 2 seconds, there is then a pause for a few seconds followed by a further spasm. A child having infantile spasms may just have little head drops that do not appear to be anything serious. IS often looks similar to common disorders such as a normal startle reflex, colic, or reflux.
Infantile spasms is in fact much more serious than the type of generalised seizure that most people would recognise, because a child with IS has a chaotic brainwave pattern that may cause loss of skills and brain damage. It is very important to recognise that a child has infantile spasms as soon as it begins because there are medications that may control the spasms. The longer the spasms last before they are treated and controlled, the poorer the child may do developmentally. If you suspect your child might have IS then getting an EEG done straight away is a priority. In the UK, take your child to an A&E department at the nearest big children’s hospital that has a paediatric neurology department.