To our knowledge, this is the first reported application of immunoadsorptio
n in a patient with multifocal motor neuropathy (MMN). The diagnosis relied
on the typical clinical features, markedly increased IgM-GM1 antibodies, m
ultiple motor conduction blocks, and motor nerve biopsy. Immunoadsorption w
as carried out in seven cycles of two sessions each within 97 days. From th
e first therapy, muscle force as well as nerve conduction velocity and cond
uction blocks deteriorated continuously. As a consequence, immunoadsorption
cannot be recommended as a treatment for MMN.