Do you need a lumbar puncture for demylination

I’ve got some demylination and the neurologist has ordered spinal MRIs and a visual evoked response test. Do I still need to do the lumbar puncture? I have no symptoms at the moment. I went because of headaches and it turned out it was just my medication for my autoimmune hypothyroidism needed to be increased. I’d never have known about the demylination otherwise. Thanks

An LP is not essential, but can provide important information (especially if it's lacking elsewhere).

If your neuro doesn't think it's necessary, then I'm sure it isn't. Maybe if the other tests come back negative, he might want you to have one, but it's an invasive procedure so better avoided if unnecessary.

Incidentally, once an LP is positive for oligoclonal bands, it stays positive forever. So, the level of symptoms or whether or not you are currently relapsing makes no difference.

Remember that you do not have to get a diagnosis if you don't want one. I have to say, however, that if something goes wrong in the future, already having a diagnosis will make things infinitely easier!

Karen x

Thanks. He has ordered one and all the tests are in the same month. Im assuming then that as I already have demylination that the LP will say for sure whether or not I have MS, but not give another reason for the demylination? Are all the tests just for MS? they don’t seem to be looking for any other causes.

About 5-10% of people with MS have a negative LP for some unknown reason, so it's not a dead cert that yours will be positive, even if you do have MS. If it's positive, then it strongly supports a diagnosis of MS, but a negative result doesn't rule out MS. (LPs can be positive in other conditions too though, so it's only one part of the puzzle.)


The test itself measures whether or not you have oligoclonal bands (a type of protein) in your CSF (the fluid in your spine and brain). This is compared to serum extracted from a blood sample taken at the same time. If there are oligoclonal bands in your CSF that are not in your serum, the LP is positive as far as MS is concerned. If there are matching oligoclonal bands in both CSF and serum, it means that your whole body and not just your central nervous system has been affected by something that has triggered a "systemic" immune response. (Systemic just means whole body.)


If someone has lesions in their brain that are consistent with MS, but more info is needed to confirm MS, a decent neuro will almost automatically order spinal MRI and an LP. Evoked potentials are very common too. Unfortunately none show MS for definite, but they do provide more info; more pieces of the jigsaw. All of these tests also allow the neuro to rule out other conditions, for example, evoked potential results can be abnormal in more than one way and the pattern of abnormality points to certain conditions. So the tests will also show up pointers to other conditions.







Thank you.