I just read through your whole thread again. I can hardly believe the neurologist can’t/won’t diagnose from the evidence he already has.
Knowing that the Covid situation is likely to slow things down in terms of getting a LP and thus a diagnosis, I think he should rethink the whole situation. (This is just my opinion - bear in mind I don’t understand the significance of the specific parts of the brain in which you have your lesions, so read my comments in the light of a) my personal but amateur experience, b) your symptoms, c) the presence of multiple lesions, and d) the fact that the neurologist has said there’s ‘evidence of a demyelinating disease’ and specifically that he’s blamed damage to the myelin for your problems.)
I gave you the link before to the McDonald Criteria which is used to diagnose MS. Have another read of it. In particular, have a look at the sections listing the clinical history plus the additional evidence needed for diagnosis:
‘Two or more relapses AND EITHER objective clinical evidence of two or more lesions OR objective clinical evidence of one lesion together with reasonable historical evidence of a previous relapse’
Additional data required: ‘None’.
And/or the next section:
‘Two or more relapses; objective clinical evidence of one lesion’ (shows DIT - ie Dissemination in Time)’
Additional data required: Dissemination in space shown by:
One or more MRI detected lesions typical of MS OR A further relapse showing damage to another part of the CNS
In my opinion (just remember I’m an amateur!), you don’t need a lumbar puncture.
If you were formally diagnosed, you’d qualify for disease modifying drugs. This could stop further damage to your myelin and thus CNS.
Also, for a clear relapse (which it’s possible/likely you are having right now), you could get steroids. Which could bring the relapse to a quicker end.
Having said that, one thing people with MS are always advised to do when experiencing what seems like a relapse, is have their urine tested in case of an infection. A UTI can often look like an MS relapse. So I’d do that anyway.
But, with regard to MS diagnosis, why not write to your neurologist. Copy your GP into the letter (consider including PALS - Patient Advice and Liaison Services - too?). Explain that you understand the huge pressures on the NHS at the present time, but that you’ve been waiting for answers since May (in fact for several years via many specialists) and for a lumbar puncture since September. Also that you don’t expect such an invasive and possibly unnecessary procedure to happen quickly.
Given the clear pattern of relapses you’ve had, which (to me and I’m sure many of us, including your neurologist I’m sure) seem typical of MS. Plus multiple lesions and evidence of demyelination, is there really a need for a lumbar puncture?
The way I’ve tended to approach neurologists, in fact doctors of any stamp, is to be properly deferential. Recognise their expertise, training and experience. But, make it clear that meanwhile you are waiting, worried, struggling to work and get on with your life. Also, that your mobility is beginning (has begun!) to suffer. That you are now finding walking aids necessary. If your foot is still not picking up, use the term ‘foot drop’. (For which you could ask your GP for a referral to an orthotist, and/or a physiotherapist.)
Sorry, I’ve gone on a bit and probably sound like a lunatic, determined to get you diagnosed. But actually I’m just pretty horrified by the long delay you’ve had and are facing.