Experiences in the diagnosis and treatment of polyneuropathies in patients with malignant monoclonal gammopathy

4 patients are reported having monoclonal gammopathies, who clinically exhibited a sensomotoric polyneuropathy being progressive during some years. The EMG showed axional failure and secondary demyelisation. In two of the patients an IgG-type multiple myeloma has been revealed, while in the other two ohnes an increase of abnormal IgM-mIg could be demonstrated. In all patients the liquor protein was found increased and the appropriate mIg has been found in the liquor. Immunohistochemically the appropriate immunoglobulins could be demonstrated on the peripheral nerve by means of immunofluorescence method. Electron microscopical studies of nerval biopsies supported the diagnosis of mIg-associated polyneuropathy. References to diagnostics and treatment of mIg-associated polyneuropathy are done.