persistant leg pain?

[bklk]

I finally submitted to lumbar fusion surgery after 7 years doubt that a central bulging disc was causing pain in an L5 distribution.  Now I still have the same pain and all post op meylo?ct, Mri, etc are normal.
  
First question would be to ask if you felt also it would be very unlikely that a central bulge could cause bi-lateral pain in the L5 distribution without effecting the S1 nerves? Aren’t the S1 nerves  central at that level and the L5 roots pretty far lateral?

I am very thin.  6’ a 142 lbs.  Could sciatic nerve compression occur in my posterior thigh, from habitual leg crossing ?  I searched this site to find a post from a women who lost considerable weight on Phen-Fen and developed symptoms, what do you think?

How long would recovery take for such a lesion?

I had EMG which was read as essentially normal but shows general mild decrease in recruitment and amplitude on the left? The only comparison with the right leg was at the superficial and deep peroneal at the ankle, and tibial H relflex and M response, these show some reduction on the left along with general reduction in recruitment on needle test.  Anything missed, suggested, or inadequate in testing?

Can you think of any potential causes for sciatic nerve entrapment such as piriformis, etc?  Can the plexus be trapped by a muscle-skeletal source or is tumor, hematoma, etc the norm?  How could the plexus and extra foraminal roots and nerves be studied/imaged?  I have read about Magnetic Resonance Neurography, but it seems investigational, any other common methods?  

Thanks, I MUST get better

[CCF-Neuro-M.D.-JT]

1. I'm assuming you mean the disc was at L5-S1.  At that level, the disc would theoretically have to be pushing out laterally to catch the L5 nerve root as it exits on one side.  I agree it would be unusual to have a disc problem at only one level that is actually protruding out centrally and catching both L5 roots without touching the S1 roots.
2. Neurological complications of habitual leg crossing tend to result from peroneal nerve compression, which manifests as foot drop, not sciatic nerve (too far up). You can get sciatic nerve problems with prolonged sitting in the lotus position (as in yoga - with your legs flexed and hips abducted), especially on a hard floor.
3.Depends on exactly what nerve (s) are involved, to what extent/degree the injury was, and your height (length of nerve in you). More details needed for prognostication, but typically at least several months.
4.Not enough info from the EMG for an accurate opinion.  Also, EMGs are very subjective and dependent on the person who performed them. What I can say is that we routinely do sural nerve sensory responses as well as tibialis anterior and abductor hallucis motor studies in addition to the ones you mentioned when looking for a sciatic problem.  The needle examination is also very important here, but again is operator dependent and should be done by someone who was formally trained in EMG.
5.You're mixing up terms. Lumbosacral plexus refers to a group of nerves that is situated higher than the sciatic nerve (not the same thing).  If it's a plexus lesion, the sensory responses would be gone or reduced in the leg.  To cause bilateral symptoms, the lesion would be rather extensive.  The majority of cases we saw in our lab doing this were due to cancer related causes like a large mass or radiation injury.  Gunshot wounds/trauma from pelvic fracture, diabetes, and maternal injuries during childbirth were also major causes that we found.  MRI/CT of the lumbosacral plexus (if this is what is suspected) can be done looking for a mass and has been helpful for some cases in our experience.

[AllieKat]

I had leg pain for 15 years with no diagnosis because all the doctors wanted to do was look at my lumbar. Turns out I have a Chiari Malformation and Syringomyelia - problem with the brain and spinal cord. These did not show up on countless lumbar mris. If you haven't had any tests further up, I'd insist on them. The logical place for leg pain is the lumbar - but it's not the only area that could have a problem that is causing your pain.

[Tomie]

I've had pain in my knee and calf - doctor performed surgery to remove a tear in the medial meniscus - now I have pain in the hip, knee, calf and instep - extruciating pain - vicodin does not even help; I had an EMG which showed possible stenosis in the back and an MRI  should compression of L5S1 - I had the knee and calf pain before the surgery; the hip and instep is post surgery; I'm taking the films to a radiologist to review and getting a second opinion.   The MRI of the knee post surgery showed a cyst and some inflammation - docs told me not to worry about that.