An MRI was performed on my 4 year old grandson, and a grey matter was shown. His doctor said it was nothing serious. The CT Scan and EKG came out normal. She said it would probably resolve as he gets older. He does have a delay. He is deaf in one ear, walks unsteadily and can t really talk that well. She gave us no name of this matter. Should I be worried?

Summarized question: What causes developmental delay in a child?