Abstract: Methods and pharmaceutical compositions in unit dosage form for treating neurodegeneration in a human or non-human animal afflicted therewith wherein the active agent is a therapeutically effective amount of a polyamine having the formula: ##STR1## or a salt thereof with a pharmaceutically acceptable acid wherein: R.sub.1 and R.sub.6 may be the same or different and are hydrogen, alkyl, hydrocarbyl aryl, hydrocarbyl aryl alkyl, cycloalkyl, or any of the foregoing wherein the alkyl chain is interrupted by at least one etheric oxygen atom;N.sup.1, N.sup.2, N.sup.3 and N.sup.4 are nitrogen atoms capable of protonation at physiological pH's;a and b may be the same or different and are integers from 1 to 4;A, B and C may be the same or different and are bridging groups of variable length.