Tingling In The Soles Of Feet, Pain In L5/S1 Disc. Normal MRI. Should I Go For Neurotransmitter Implant?
Hello. First things first, thank you for taking the time to speak with me. Having said that, you will find me to be somewhat of an anomaly. I've had lower back back for the past 6.5 years ... I realize this is a general statement so let me elaborate. 6.5 years ago I carried about 15 loads of gravel and the very first symptons started that night which included tingling in the soles of both feet, significant pain in what appears to be the L5/S1 Disc. I've been on pain medications since then with multiple MRI's performed and no evidence of a bulging or herniated disc (or so I'm told). Pain is made excruciatingly worse when sitting which is why I've had to use a lumbar cushion for the longest time. Finally, I had a discogram performed several week ago which showed no tears in the annulus fibrosis however; the pain from the procedure was obviously worse and has still yet to subside. Multiple neurosurgeons have said that the disc height and anatomical structure is fine along with the spine being stable. They are recommending either an IDET procedure, a neurotransmitter implant or as an absolute last resort a fusion. All I've been told is tha that based ont he discogram that the disch is hypersensitive to pain.
In addition, the disogram on the L5/S1 disc showed an opening PSI of 30 and inflated to 80 PSI at which point the pain was "concordant" at 70 PSI. The L4/L5 was the control disc and that also revealed an initial PSI of 30 and also inflated to 80 PSI however; no pain was evident from this area..
Long story short: What are my options?
Thank you for your detailed query. In my opinion, you would be an ideal candidate for a neuromodulatory procedure. This includes procedures like Intrathecal drug infusion pump implantation. Again, in my opinion, I could consider the 2 options in the order listed.
If your lumbar discs are anatomically intact, I do not know if IDET will be beneficial. However, I am not experienced in IDET. As far as the other 3 options are concerned, surgery for Chronic pain is my area of special interest. I have seen many patients improve with a Spinal Cord Stimulator. However, you will need to be counselled before the procedure and your expectations assessed. Surgical procedures for pain are intended not for complete cure for the pain but to mitigate the pain to a large extent. So if you are one who says I would definitely consider a partial improvement in my pain is worthwhile, then this procedure could be considered in you. Further, the first step in the procedure is a "trial electrode" insertion. So, you get a trial electrode put in the back, and you see what it feels like to have an electrode in, whether there is a beneficial effect or not. The wire will be connected to an external stimulator where the settings will be altered to find the best stimulator parameters for you. You get to live with this wire coming out of your back for a few days and then jointly the doc and yourself takes a call whether to proceed with the implantation or not.
Please do let me know if you need more information. If you want to have a one to one consultation with me or better still consult me in India, you are welcome! Finally, you are not an anomaly. There are thousands of patients like you out there who have so called "normal scans" but suffer in pain. There are also a few of us like me who attempt to try and relieve your suffering if we can!
Best wishes
You do have a valid point of view. However, in chronic lower back pain, all available "potentially curative" modalities are very good at relieving the radiculopathy- or sciatic leg pain. However, they rarely do little to improve the back pain. Further, if the disc looks intact grossly, there are various theories about "discogenic pain"- some of which are not universally accepted. Procedures like IDET have been designed to help in these situations- but the follow-up period is limited to conclusively say if it will help or predict to what extent it will be useful. As I mentioned before I have no experience with IDET. As far as Lumbar fusion goes, there are some studies which say that it helps roughly 50% of patients with their low back pain. I have personally seen it work very well at least in the short term in a few patients when I was working in a spinal unit in the UK. But again, whether it will work in you is a toss of the coin (50% probability of heads!)
As far as my initial advice goes, I need to revise my options given the fact that you don't have radiculopathy and only have LBP. The neuropathic leg pain, but doesn't relieve back pain consistently. Therefore in terms of neuromodulatory options, it would be probably the intrathecal drug infusion pump that would be more suited for you. There is another newer modality called high frequency spinal cord stimulation being promoted in Belgium which supposedly helps low back pain- but again experience is limited.
One way to go about is to look at the "potentially curative" options like Fusion or IDET initially, but with the full knowledge that you may back to square one after that. Then it may be a better option to reassess the situation to see if there may be still a need to consider a pain relieving procedure. There are a significant proportion of patients who still have low back pain and leg pain after all sorts of back surgeries. The exact cause of the pain sometimes cannot be found even after looking carefully with all the tests available in medical science. In such a circumstance, measures to relieving pain may be the only option available.
I hope this has helped clarify your doubts a little and hopefully not confused the issue more! Please do let me know if you have any more questions or else please rate the answers and give your feedback.
Question: with discogenic pain -- Could irritants be given off by the aggigated annulus fibrosis and irritate the the nerve roots causing the foot tingling (knowing what we know about dermatomes)? This was the very first symptom after the extreme pressure I put on my back over 6.5 yrs. ago. If yes, would an implanted neurotransmitter help to quell that as well or does it strictly target pain receptors?
Again, no pain down the back of the legs except for intermittent tingling. The chronic aspects are the pain in the L5/S1 (especially while sitting) and the tingling in the soles of the feet.
Thanks again for your time.
Thanks for writing back.
I agree that you have a reasonable plan of action.
"Discogenic pain" - For a long time, people did not understand the causes of low back pain (not that they understand it fully even now!). One of the causes of LBP (lower back pain) is now thought to be from the nerves that supply the disc itself. This is called discogenic pain- pain originating from the intervertebral disc. As I said earlier, the debate is not completely settled about whether this entity is valid or not.
It is the nucleus pulposis which is supposed to cause the irritation/inflammation and when the covering of the nucleus- i.e Annulus is torn the nucleus comes out and irritates the nerves around. What I am not sure is whether this process could be going on for 6+ years.
The neurostimulator does not do well for low back pain. Intermittent tingling in the legs could mean some irritation on the S1 nerve root happening as well.
Hope this helps.
Regrads,