Many cases of Shaken Baby Syndrome are brought in for medical care as "Silent Injuries."
In many cases, babies who do not have severe symptoms may never be brought to a doctor. What makes shaken baby syndrome so devastating is that it often involves a full brain injury. And because the brain doesn't heal like other organs, these injuries are life long and impairs the child's ability to learn.
Abusive head trauma often causes irreversible damage including partial or total blindness, hearing loss, developmental delays, speech and learning difficulties or problems with memory and attention.
For more information check out: http://www.cdc.gov/concussion/HeadsUp/sbs.html