Have you looked into this option for yourself?
It certainly seems like a good one for those of us with intractable head pain that does not respond to any forms of treatment or meds.
I fall in this category, now going on twelve years of continuous headache.
It's a tough battle.
Do you have any info you could share on the ONS?
I have a call in to medtronics to see if there is a contact in Canada.
Also i have recently found two facebook groups i have joined, one is for those with the ONS and the other for new daily persistent headaches.
Check them out as there is a lot of info and some really positive and hopeful stories
You can just ask to join the group and you will get the green light.
I hope this info can help someone here.