the spasms in the left side of the face can be related with back pain. if that was the case, there would be something disturbing your Central Nervous System, brain/spine. it can be something temporary, months or even years, due to the immune system "adjusting" itself.
I was having the MRI done because I was having back pain
One of the safety precautions is to remove any hair clips or anything of the sort because it can potentially create a problem. You should get that checked out asap.
A metal object subjected to an MRI will cause the hairclip to heat up. There should be no internal damage. Any injury would be the same as if a hot metal object were to be placed adjacent to your scalp. In addition the MRI will not provide a clear image. They should not charge you for another. It won't get worse. Internal damage comes from metal implants or shrapnel. The fault lies in the operator, whose failure to insure you had no metal anywhere is inexcuseable. There is an element of malpractice involved. A formal written complaint should be made to the hospital via registered mail.
they are probably related with the reason why you took the MRI. which was the reason?