spinal tap & myelogram

has anyone ever had a spinal tap and a cervical myelogram at the same time? I have a metal plate in my neck due to previous neck surgery and the mri only shows the artifact. The doctor told me the only way to see what is going on there is to do a myelogram. I also have lesions on my brain that show a classic ms pattern so it was also suggested that I get a spinal tap. I had a myelogram 20 years ago before lumbar surgery so I know they are hell! I ended up with the spinal headache and the vomiting. I am certainly terrified to go through it again. should I have both done at the same time? they told me it could be done. the doctor thinks I may have pressure on my spinal cord behind the plate.Any help with this question would be appreciated. Thanks