Severe peripheral neuropathy after exposure to monosodium methyl arsonate.

A case of severe peripheral neuropathy after several days of exposure to a pesticide spray containing monosodium methyl arsonate (MSMA) is reported. The clinical manifestations of symmetrical peripheral neuropathy with stocking-glove sensory deficit, decreased position sense, decreased and absent deep tendon reflexes, and muscle wasting are consistent with those described in other cases of arsenic intoxication. The anemia, leukopenia, and bone marrow changes of dyserythropoiesis in this case are also similar to those previously described with arsenic intoxication. The authors discuss the possible contribution of toxicity from exposure to other pesticides.