Leucoencephalopathy, transverse myelopathy, and peripheral neuropathy in association with glutamic acid decarboxylase-65 (GAD) antibodies in children with cancer.

Neurologic toxicity may occur as a direct effect of cancer and its therapy or indirectly because of a dysfunctional immune system. The authors report the development of axonal neuropathy, myelopathy, and leucoencephalopathy associated with glutamic acid decarboxylase-65 (GAD) antibodies in 4 children with progressive cancer who were heavily pretreated. Three patients with refractory leukemia and 1 with Ewing sarcoma developed paraplegia with sensory level and dorsal column dysfunction. Three developed leucoencephalopathy and 1 died of neurologic disease. All had high serum titers of GAD antibodies during the progressive phase of the illness, and the antibody levels returned to normal with the stability of the neurologic disease. Three survivors are showing gradual recovery. This syndrome of central and peripheral nervous system toxicity may have resulted from chemotherapy toxicity or from immune dysfunction, as suggested by the high GAD antibody titers.