Infantile Spasms and Why…?

The interesting thing about infantile spasms (west syndrome) is that it happens to infants, not to adults (the clue was in the name). Infants do grow out of it. We also know that Infantile Spasms can have a huge impact on a child’s development. The obvious questions all revolve around “why?”:

  • Why do children grow out of it?
  • Why does it have such a huge impact on a child’s development?

Recent Research

While not covering Infantile Spasms directly, this article from the BBC details the results of research, published in the Journal of Neuroscience into language development in Toddlers.

The study which was lead by Dr Jonathan O’Muircheartaigh, from King’s College London, looked into brain formations and language development. The research showed that “myelin”, a kind of insulation that forms in the brain develops over time and by the age of 4 the myelin has effectively locked into place.

Myelin is an electrical insulator, as we grow, myelin develops around the neurons which form the brain. It prevents electrical activity from escaping from a neuron, and helps make a neuron faster at propagating an electrical signal within it.

The study indicates myelin formation stops when we reach the age of four. It also suggests that a lack of myelin, as we grow, helps us to learn and pick up new skills and abilities quicker. Without myelin new connections between neurons can form quickly, effectively signals will jump from one neuron to another. After myelin coats a neuron it will insulate it, preventing these connections from being made.

The study also suggests that there may be a link between myelin and slow language development, a key symptom of Autism.

The interruption of this process of forming new connections, with conditions like West Syndrome will have a large impact on a child’s development, since the connections which form between neurons when we are under four appear to be more difficult to change as we age. This causes learning difficulties. It also explains why Infantile Spasms can have such a large impact on development; it interrupts our neurons, during a crucial window of development, as they try to make connections between each other and form our brain.

Myelin and West Syndrome ( Infantile Spasms )

In 2007 research by Shiga University of Medical Science in Japan looked at a link between delayed development of Myelin and Crytogenic Infantile Spasms. The team in Japan concluded that while they did find evidence of delayed myelin development in 55% of the cases they looked at, they did not see a clear positive correlation between delayed myelin development and Infantile Spasms.

Ticking off the “Why-s”

From what I read it looks like myelin could be a factor, but it’s not the root cause (if a single root cause exists). While I think I’ve answered why Infantile Spasms has such a large impact, I still haven’t completely understood why babies can grow out of it. - I guess that’s a job for more reading at another time.