[amnesia]

Can anyone here please describe the differences/symptoms of these conditions? My son is 11 years old and just starting 5th grade. He attends a small private school where his teacher has alerted us to the fact that he is having "difficulty understanding" the topics being presented. She says that he just "looks at me with a confused look while I am teaching". At home, when we review the topics and do homework he will patiently sit and listen to what you are saying, but I notice he does have difficulty applying the various processes. If he is working on a book report, for example, if he manually writes it on paper he has a lot of difficulty recounting the story lines with any degree of accuracy or descriptiveness. The punctuation is non-existant and there are usually multiple spelling problems. Lately, he has started doing the reports on a word processor at his teachers request, and the difference is unbelievable. He clearly and vividly conveys the storylines and uses correct punctuation/spelling. It is like someone else has done the work. Why would he be able to do this so much more effectively on the computer?
I also notice that he has difficulty following a group of verbal instructions. He will follow the first part and then quickly lose track of what I have told him. We started doing daily checklists and that has been helpful. For a long time I just thought he was being lazy but now I am beginning to see what his teacher is describing to me. His pediatrician has referred us to a pediatric neurologist for testing. He is the one that suggested auditory processing/ADD . I am feeling guilty that I did not recognize his difficulties earlier but the pediatrician said that they can often compensate until around this age/grade when more complex tasks are introduced.
I have an appointment for him this coming Tuesday and I would love it if anyone could give me sugesstions regarding (1.How to approach this with my son--he is really sensitive and tends to see things with the idea that he has done something wrong. 2. Anything I should tell/ask the neurologist ? 3. Any suggestions would be greatly appreciated!). Thank you all in advance for your help!