The invention relates to the use of a chemical substance selected from the group consisting of N-'2-hydroxy-3-(1-piperidinyl)-propoxyl !-pyridine-1-oxide-3-carboximidoyl chloride, the optically active enantiomers and the mixtures of enantiomers thereof and pharmaceutically acceptable salts of the racemic and optically active compounds in the preparation of a pharmaceutical composition for the treatment or prevention of neurodegenerative diseases.