Toxic effect of intraventricular interferon-alpha in subacute sclerosing panencephalitis.

Intraventricular interferon (IFN) administration has been shown to improve the course of SSPE. However, in 2 patients treated with intraventricular IFN-alpha-2a over a long period, we observed the appearance of clinical and EMG signs suggestive of upper and lower motor neuron pathology. These signs improved slightly in one patient after the discontinuation of IFN. It is suggested that this poly-peptide may act on specific kinds of nervous cells which selectively suffer together in various well-known neurological diseases.