There's a subgroup of children diagnosed with the autistic spectrum disorder that have regression of symptoms. Regression of either speech and language or of social relatedness and connectivity. In any condition, this is not normal, this is something of concern. The reason for regression is not clearly understood. Sometimes children are diagnosed to have a seizure disorder, but this is not necessary. A third of children with autism may have some kind of abnormal EEG activity or a full blown seizure, but the regression and loss of symptoms, loss of developmental milestones is something that is seen and is a reason for alarm, because parents absolutely get concerned and approached the pediatrician for that.
Sometimes parents who do not pick up on this but need to be questioned about it particularly and go back in history or go back and look at her video and say, "Oh, my child used to be able to babble and say a lot more words, and they've just stopped saying it." It may be for a period of six months to a year. Sometimes the words come back and sometimes they don't. Diagnosis that needs to be considered when you have language regression like this is a syndrome called the Landau-Kleffner syndrome. That is a particular syndrome that is seen in a small group of children who lose language and there's treatment with the use of steroids that may be beneficial. It would be important at that point to involve a neurologist, get a 24-hour EEG done and evaluate it. There's a correlation between loss of language and abnormal EEG activity. Loss of motor milestones can be seen in children who have a neurodevelopmental disintegrated disorder and that is something that also needs further medical evaluation.