New and known 4-cholesten-3-one oxime derivatives (I) are used as medicaments. 4-Cholesten-3-one oxime derivatives of formula (I) and their acid addition salts are used as medicaments. X = O or NOH; R = (CH 2) 4CH(Me) 2, (CH 2) 3CH=C(Me) 2, (CH 2) 3CH(Et)CH(Me) 2, trans-CH 2CH=CHCH 2CH(Me) 2, trans-CH 2CH=CHCH(Et)CH(Me) 2 or trans-CH 2CH=CHCH(Me)CH(Me) 2. An independent claim is also included for new (I) other than 3-hydroxyimino-4-cholesten-6-one and 4-cholestene-3,6-dioxime. [Image] ACTIVITY : Neuroprotective. 3-Hydroxyimino-4-cholesten-6-one had a positive effect on the survival of bone-marrow motoneurons at a concentration of 3 mu M, as indicated by a ratio (not defined) of 0.6. MECHANISM OF ACTION : None given.