The present invention relates to a pharmaceutical composition for the treatment and/or delaying the onset of clinical symptoms and/or delaying the progress of a neurodegenerative disorder caused by prions. The composition of the invention comprises as an active ingredient DMSO, and optionally further comprising pharmaceutically acceptable additives and/or diluents. The composition of the invention is particularely applicable in the treatment of neurodegenerative disorders associated with enhanced accumulation of PrP.sup.Sc into amyloid plaques. The invention further relates to methods of treatment of a neurodegenerative disorder caused by prions and to the use of DMSO in the preparation of a pharmaceutical composition for the treatment and/or delay of the onset of clinical symptoms and/or delay of progress of neurodegenerative disorders caused by prions.