Electroencephalographic abnormalities in interferon encephalopathy: a preliminary report

Although several studies have shown that interferon does not readily cross the blood-brain barrier, recent reports have described central nervous system effects in patients receiving interferon. At our institution, we encountered three patients who had symptoms of toxicity of the central nervous system (somnolence, confusion, and gait difficulties) in association with electroencephalographic abnormalities while receiving alpha 2-interferon therapy for multiple myeloma. The electroencephalogram showed diffuse slow-wave abnormalities in two of the patients and generalized sharp-wave discharges in the third patient. Because the use of interferon is increasing, physicians should be aware of the central nervous system complications and the electroencephalographic changes that can be associated with such therapy.