Dr. Nicholas Silvestri interviews Dr. Thomas Brannagan about the article Evaluation of patients with refractory chronic inflammatory demyelinating polyneuropathy. Reasons for therapeutic failure in CIDP are inadequate immunotherapy and alternative diagnoses. Certain clinical and electrophysiological features help to distinguish true CIDP from mimics. Once CIDP is confirmed, optimization of IVIg dosing, addition of corticosteroids, plasmapheresis, or chemotherapy results in consistent improvement. Caution is advised when using response to therapy to diagnose CIDP. Muscle Nerve 55: 476-482, 2017.