Thanks for posting your query at DoctorSpring.com
I have gone through your question in detail and I can understand what you are going though.
The fact that your son rarely remembers what he has said during such a period of rage suggests that it could be a seizure activity. During a period of seizure, a person may behave or say something which he doesn't remember later-on. Simple partial seizures are such types of seizures which occur in clear consciousness. They can be ruled out with the help of an electro encephalogram (EEG). EEG will help in identifying such seizres.
If EEG is normal, then such behaviors could be a manifestation of oppositional defiant disorder. These are generally treated with psychological principles such as providing proper attention to your child, dedicated time to your child, behavioural therapy, play therapy etc. These are generally guided by a clinical psychologist. The basic crux behind such a problem is when the child doesn't get proper attention from parents then he seeks attention through such disruptive and annoying acts. Instead if we start providing proper attention to the child then these annoying acts will reduce with time.
So first you need to see your doctor and get an EEG done and if it is normal then a clinical psychologist appointment for behavioural therapy will be required.
Hope this helps,
IN case if you need any further clarifications, do let me know.
Dr. Srikanth Reddy MD