The best place to go is the DSM iv. Or to call it by its full name the Diagnostic and Statistical Manual of Mental Disorders. You will be able to access via most reference libraries. There is an abridged version someone has put on the web at
I really appreciated reading that sensory processing deficits can be inconsistent; meaning, present one day and not the next. That is absolutely my experience
When I was younger I remember having many sensory issues that went undetected or were seen as being a disrespectful child. Most of my symptoms have persisted