[Polyneuropathy and monoclonal IgG/IgA gammopathy--differential neurography on the basis of two patient cases].

With higher age, monoclonal gammopathies are more frequently diagnosed as the underlying cause of polyneuropathies. Whereas in approximately one-third of the patients, the gammopathy is related to multiple myeloma, lymphoma, other lymphoproliferative diseases, or amyloidosis, the remaining patients are diagnosed with monoclonal gammopathy of undetermined significance (MGUS). As underlined by the two reported cases, in IgG/IgA-type gammopathies electrophysiological findings of axonal lesions in mildly impaired patients are more likely to be found in patients with MGUS, while demyelinating polyneuropathies with more severe clinical impairment are more commonly seen in myeloma patients.