Neurologic sequelae following interferon therapy of juvenile laryngeal papilloma.

Human leukocyte interferon at doses from 2 million units every two days to 3 million units daily was given to a 2-year-old boy for the treatment of recurrent juvenile laryngeal papilloma. After 7 months of treatment the child developed spastic diplegia, which persisted despite the discontinuation of interferon therapy. The clinical picture was consistent with an upper motor neuron lesion; no evidence of peripheral neuropathy was found.