[Amyotrophic lateral sclerosis with multiple myeloma].

Motor neuron diseases (MND) associations with paraproteinemia, lymphoma, hexosaminidase A deficiency and heavy-metal intoxication are of great interest. A case of amyotrophic lateral sclerosis (SLA) associated with multiple myeloma (monoclonal IgG paraproteinemia and K light chains) is reported. The detection of abnormal protein in 1988 and the increase of its serum level during 1989 were strictly correlated with the beginning and the worsening of the neurological disease. Shy and coll. in 1986 affirmed that association of paraproteins with MND is probably not merely the fortuitous association of a common laboratory abnormality and an uncommon disease. The reported case provides elements for a causal association between paraproteinemia and MND.