Hello~I am so sorry your wife is having these issues. I highly suggest seeing a good chiropractor; she very well might have some pinched and misplaced vertebrae in her neck, this can certainly cause the symptoms she is having. The chiropractor will take x-rays of her neck and they will show exactly what is going on.
I hope she gets better soon, please do try the chiropractor. God bless you.
She probably has a significant magnesium deficiency (tissue not blood) which cannot be verifies with a standard blood test.
She would need an RBC magnesium test for that.
I would suggest she gets some oral magnesium threonate and some transdermal magnesium oil.
It would be a better option in the long run than muscle relaxing drugs.
Cheers,
Niko