Can someone who was diagnosed with MS by both monthly evoked response tests and a lumbar puncture (but before there were M.R.I.'s), but has a negative M.R.I. now, can they still have the disease?
By monthly evoked response tests, I assume you are referring to visual evoked response (VER) and somatosensory evoked potential (SSEP). Since the advent of MRI, we use the VER and SSEP less frequently. VER measures the function of your visual system and SSEP (how we use them) tend to measure the ability of your spinal cord to transmit electrical signals. If there are delays in these tests, it indicates that there may be an MS lesion or scar within those pathways. The lumbar puncture (LP) looks for signs of chronic inflammation that is specific for the nervous system (and tends to be positive in 90 to 95% of MS patients). With that said, it is possible to make a diagnosis of MS based on these tests (or your story and neurologic exam alone) without the use of MRI.
However, it is a red flag in my mind to make a diagnosis of MS with a completely normal MRI of the brain. There are mimicking diseases of MS that can render a normal MRI scan of the brain but show disease in the optic nerves and spinal cord. If there is any question, getting another independent opinion from an MS specialist is reasonable. Hope this helps.
-A. Scott Nielsen, MD
Virginia Mason MS Center