I also find it very odd that narcotic pain meds relieve some of my neurological symptoms. Not talking about pain....I get relief of other me/cfs symptoms like brain fog, clarity and memory, visual disturbances, tinnitus, and energy......even some of the PEM. It's not a cover up due to euphoria, it actually relieves some of the symptoms. As far as I understand, opiates would only affect those receptors and have nill to do with other neurological problems.....but they do for me. Must be some downstream effect like on endorphins or something. And it wasn't a fluke because I've had this happen years past as well. NSAIDS don't do this, so it's not an anti-inflammatory effect. I dunno, but I'm not willing to live on narcotics for this purpose. Gonna see what my me/cfs doc has to say about this.