I think I've tracked it back to either having my cervical stimulator up too high or bad posture and having put a strain on my neck muscles. It seems that as I'm healing I'm having to turn the cervical stimulation down during the day....less inflammation? leads scarring in a bit? Probably a bit of both. I guess I'm the odd duck here as I have to turn both my remotes up when I go to bed or I don't get enough pain relief to sleep. I've definitely noticed I'm sleeping better these days and I'm a nicer person to be around