[Grand mal like attack by interferon injection in case of renal cell carcinoma]

We performed a radical nephrectomy for renal cell carcinoma on a 60-year-old female. We began to give alpha-interferon (natural type), she had an attack of tonic clonic convulsion (like grand mal attack). There were no abnormal findings in head computed tomography, nor hematologic tests. We ascribed the attack to interferon, and stopped giving it. Because there was an abnormal wave in EEG, she was given an anti-convulsant per os. One month later, the electroencephalogram became normal and she showed no neurological symptoms nor findings.