I caught bits and pieces of a show on TLC called "Mystery Diagnosis". The episode was about a girl who had a mild head injury. Some time later she had major symptoms of fatigue, etc. After something like 4 years her docs finally figured out her pituitary gland was damaged in the car accident.

I will post a link to the site here, although I don't think this episode is available for viewing yet. Keep checking back if interested...something to look out for for sure!

http://health.discovery.com/tv/mystery-diagnosis/