[IgM kappa lymphoma with antisulfatide antibodies revealed by cervical motor neuropathy simulating amyotrophic lateral sclerosis]

It is well known that polyneuropathy is associated with monoclonal IgM kappa.

We report the case of a 79-year-old man with lymphoma and motor neuron disease at cervical level simulating amyotrophic lateral sclerosis (ALS). Neurological deficit with inflammatory process evolved within 4 months. Electrophysiological findings showed increased and enlarged muscular potentials with neurogenic patterns. Nerve conduction velocities were normal, with neither multifocal neuropathy nor persistent conduction blocks. Besides mixed cryoglobulinemia type II, antisulfatide antibodies issued from monoclonal IgM were found. They were directed against myelin glycosphingolipids. No antiganglioside GM1 antibodies could be detected. This not only evoked ALS but also proximal motor axonopathy related with monoclonal IgM.

This case suggests that antisulfatide antibodies often present in sensitive demyelinating polyneuropathy could also be involved in lower motor neuron syndrome.