The invention is directed to the use of a compound of formula I, as defined herein, to a pharmaceutically acceptable salt thereof to a pharmaceutical composition containing a compound of formula I, and to a combination of a compound of formula I with a pharmacologically effective cholinesterase inhibitor to treat a mammal, including a human, for a disorder or condition selected from the list including Alzheimers disease, Huntingtons disease, Parkinsons disease, non-Alzheimers dementias and ALS.
