I'm one of these patients. I was successfully treated for an autoimmune brain condition of some sort. To this day, none of our clinical testing has ever showed any abnormality. I was treated based on detailed medical history and my insistence that my self-reported symptoms be taken seriously.

It took months to find a physician willing to treat me, and I still to this day don't understand what they were so afraid of. My self-reports of symptoms, patterns of exacerbations, and positive response to corticosteroids were consistent and unequivocal.

I was in nursing school at the time, and I don't know if that helped or hindered me. But I finally figured out how to speak the language that my physicians could understand, even though I was the patient. That shouldn't be necessary.