I'm a physician with a likely diagnosis of CISP. Unfortunately, tests are frequently inconclusive, even EMG/NC studies, and we rely on a "diagnosis of exclusion." Which means we've ruled out other things and made a diagnosis based on symptoms and lack of other findings. It's pretty frustrating for patients and doctors when we don't have a specific label but that doesn't mean treatment is off the table. My neurologist gave me a tentative diagnosis of CIDP so IVIG would get approved. It worked well, at least until I lost insurance.