ABSTRACTIntravenous immunoglobulin [IVIg], plasma exchange [PE], and corticosteroids are efficacious treatment in chronic inflammatory demyelinating polyneuropathy [CIDP]. IVIg is effective in multifocal motor neuropathy [MMN]. NIS, NIS‐weakness, sum scores of raw amplitudes of motor fiber (CMAPs) amplitudes, and Dyck/Rankin score provided reliable measures to detect and scale abnormality and reflect change; they are therefore ideal for office management of response‐based immunotherapy (R‐IRx) of CIDP. Using efficacious R‐IRx, a large early and late therapeutic response (≥ one‐fourth were in remission or had recovered) was demonstrated in CIDP. In MMN only an early improvement with late non‐significant worsening was observed. The difference in immunotherapy response supports a fundamental difference between CIDP (immune attack on Schwann cells and myelin) and MMN (attack on nodes of Ranvier and axons). Muscle Nerve 52: 488–497, 2015