Hi I just joined this forum and I thought I'd share my story. I'll summarise as best as I can. Like many people here, I'm still searching for answers and a solution.

Male, 28 y/o, slim, non-smoker, non-drinker, plant-based diet.
In mid 2017 (26 y/o) I started suffering lumbar spine pain; I thought at the time presumably due to intense weightlifting, long distance running and not taking care of my body. It just worsened and I had two acute overnight attacks of radicular nerve pain down the back of my left leg. By Dec. 2017 I could not sit in a chair anymore and the nerve pain down the back of the left leg was becoming chronic. It went from the top of the glute all the way to the heel. MRI showed a single moderately diseased disc at L4/L5 but there was no neurocompression (no big bulge / herniation and no stenosis). All other spinal segments were free of disease. I continued to worsen. I started to get tingling on both of my thighs while walking. I met a new physio in Mar. 2018. He gave me new exercises to do. By this time standing and walking were getting a bit sore and my lumbar spine was starting to feel very fragile. I couldn't sit any more at all and sleeping was getting tough due to the burning down the back of the left leg.

These new exercises took the situation into explosive mode. I had a very massive and acute exacerbation of my symptoms. Suddenly the nerve pain was incredibly severe and relentless. It was present in both legs anteriorly and posteriorly, left worse than right. My sitting tolerance remained at zero but my standing and walking tolerance went to near zero as well. I was effectively bedbound. But even totally immobile I was in severe pain. There was so much neuropathic pain (very intense burning, prickling etc. sensations). Despite this, I had no neurological deficits (no weakness, reflex problems, muscle loss etc.) I had another MRI and it showed the same as last time: a degenerative disc at L4/L5 but no evidence of neurocompression and all other spinal segments were fine. So my pain was overwhelming and severe, yet the MRI picture didn't explain why.

By all accounts, my spine looked mostly fine. The lack of findings on MRI and the lack of neurological deficits took me into a period of time where it was very difficult to get taken seriously and to get a treatment plan. The doctors, I assume, thought I was being hysterical when describing the pain. My spine was actually tender to touch at the L4 / L5 level, my back 'burned' at this level and my neuropathic pain I subjectively felt radiated from there. It was hypothesised my diseased disc was causing chemical irritation of the nerve roots and also was the cause of the lumbar spine pain - although this would be a very rare presentation given the very banal MRI findings. I had two caudal epidural injections (Oct. / Dec. 2018) and they did not help. They increased lumbar spine pain a lot though for the first 2 - 3 weeks after having them. I had fasciculations in my left heel at night sometimes and it progressively worsened. I had a repeated MRI in Dec. 2018 and a high intensity zone was visualised on the L4 / L5 disc suggesting the presence of annular disruption (this was not confirmed with a discography). In Jan. 2019 I had an artificial disc replacement at L4 / L5 with an LP-ESP disc prosthesis. Actually this operation had positive effects on my lumbar spine pain. I had sitting and standing tolerance restored to mostly normal. So it seems like there was disc pathology involved somehow.

It was a minor victory though, as the operation failed to improve the neuropathic pain in any way. I continued to have severe bilateral neruopathic pain constantly throughout the day. I also started to have lots of stinging and strong bruning in my lumbar spine and these sensations increased with time. Time didn't appear to be imrpoving things and actually fasciculations appeared to be spreading and worsening. It seems that even if the disc was involved, my nerves had become diseased in an of themselves. Despite this, I remained without any neurological deficits. By May. 2019 I had grown totally and utterly despondent with the situation. Pain had destroyed me emotionally. I was begging my doctors to try figure out what the problem was. I must stress, the pain was and is very severe and it is constant. It is so difficult to focus during the day and to get to sleep at night. I am mostly homebound and I wear shorts, even though it's the winter, because fabric seems to worsen it a bit. Any amount of activity (as simple as a short walk) make pain noticeably worse for a few hours before return to base severe pain.

I had an EMG / NCS and this failed to show the presence of any lesions (I'm not sure how rigorous the procedure was) - it was 'unremarkable' for a few peripheral nerves in both legs. I then had a full battery of radiological and lab tests. These included CT lumbar spine scan (no contrast), full spine MRI, brain MRI, SIJ and Pelvis MRI,flexion / extension x-rays and the following bloods: FBC, Comp. Met. Profile, C3, C4, HLA-B27, CTD screen, ANCA, tTG, Rheum. Factor, CCP, CK, CRP, Urate, TSH, Free T4, Vit. D, Albumin, IgG, IgM, IgA, Electrophoresis, ACE, HIV 1+2, Hep B+C, Lyme disease, Ferritin, B12, Folate, HbA1c, PSA, Glucose. I was assessed by a rheumatologist, neurologist and neurosurgeon.

The neurosurgeon did not recommend any further surgical intervention. This makes sense to me as my prosthesis is functioning fine and there is no evidence of nerve entrapment and all other spine segments were free of disease. The rheumatologist said that my lab work and lack of symptoms don't suggest at a systemic illness, this I agree with too. The neurologist wasn't very clear on his opinion, he didn't give a diagnosis but since my EMG / NCS was clean, radiology was clean and my tests were seemingly all fine he referred me for chronic pain management. Of note: the SIJ MRI showed some oedema in the right SIJ joint and some osteophytes but this was considered not clinically significant or explanative of my symptoms of diffuse lumbosacral burning with lumboscral radicular pain which is worse in the left leg.

I had a transforaminal epidural injection and pulsed radiofrequency of the dorsal root ganglion bilaterally at L4 / L5 in late Sept. 2019 and this failed to help at all. It was a painful procedure as well. The next thing to try is apparently a spinal cord stimulator but I feel like this is not going to help.

So here I now am. In summary, I have severe bilateral asymmetric neuropathic pain and fasciculations in both legs as well as intense burning and stinging in my lumbar spine; these symptoms are constant throughout the day and worsen with activity. It does not appear to be improving much with time and in total it has been ~20 months since Mar. 2018 when things went from manageable to insane.

I basically can't fathom why I have such severe, chronic dermatomal pain without any evidence of anything wrong with me (clean imagery, electrophysiology exam, labs and no neurological deficits). Just applying Occam's razor I think something like the following may have happened: my disc tore badly and this prompted a rare non-systemic auto-immune response which affected surrounding tissues. In particular the PNS became chronically inflammed and there was widespread, multi-dermatomal radiculitis. The disc was not dissected for many months, so the nerves potentially maladapted to this. Now they had bad widespread damage, and are struggling to heal. Or else they have healed incompletely. The lesions were not big enough to be found on EMG / NCS yet are enough to cause severe pain (?).

Roughly, I think I could have had a trauma induced self-limiting form of non-diabetic lumbosacral radiculoplexus neuropathy. Or some other kind of non-systemic vasculitic process that is only causing pain and fasciculations.
I have not looked into this much, but I could perhaps also have a small fiber neuropathy?

I recently trialed high dosage corticosteroids (70 mg for 3 weeks, and this was pushed up to 100 mg for the past 4 days). There has been seemingly no improvements to pain or fasciculations from this. I have tried antiepileptic and antidepressant medications (gabapetin, amitriptyline, venlafaxine) and none helped at all, and mostly just messed with my mood and were hard to come off of. I would be very hesitant to keep trying different antiepileptic and antidepressant medications. I have been prescribed ketamine oral syrup 50 mg x 3 a day and it doesn't really seem to help to be honest.

I'm at a loss. I don't see a clear answer here. I have thought about having an MRN and asked my doctor about ordering it recently. Even if it verified abnormalities, I'm not sure what it would mean about a diagnosis, prognosis and treatment. I feel like my body is just fundamentally broken. 20 months is a long time to have spent 'healing' and to see very minimal improvements. 10 of those months my spine has been free of disease as well. Some people have enough damage to case weakness and axonal damage but they improve quite rapidly. I am perplexed.

Well, that's it really. Sorry about the length. I think it's just pain management and waiting to see if it spontaneously resolves.

EDIT: I'll just pre-emptively say that I've tried CBD in various ways, NSAIDs, various physical / physiotherapy protocols, mindfulness / relaxation stuff, therapy for pain depression and none of this stuff helps an iota unfotunately. I genuinely feel like I'm at the end of the road.