Amyotrophic lateral sclerosis with IgM antibody against gangliosides GM2 and GD2

We report a case of amyotrophic lateral sclerosis (ALS) with IgM antibody against gangliosides GM2 and GD2. A 57-year-old woman presented with slowly progressive muscular weakness of the upper extremities and dysarthria. She fulfilled the clinical and electrophysiological criteria of ALS, and died from sudden suffocation about 3 years after the onset of illness. The patient's serum IgM antibody was shown to recognize the structure shared by GM2 and GD2. Since anti-GM2 antibodies have been implicated in motor neuropathy or motor neuron syndrome, this rare case might contribute to the understanding of the immunological aspects of ALS.