Bilateral Leg Quadricep Weakness, No Pain

hi,divedoc. Whatever is happening after ten minutes of activity is not happening while static and supine in the MRI or while stationary with the EMG or the Nerve conduction flow.
A chiropractor will give you the best physical exam for motion mechanics. There could be restrictive flow during activity. It rather sounds like central canal stenosis. It could be vertebral slippage spondylothesis aggravated by particular movements. https://www.cedars-sinai.org/health-library/diseases-and-conditions/s/spondylolisthesis.html

Thank you for the information. I forgot to add that along with the foraminal stenosis I have a grade one anterolisthesis at L3-L4 with unroofing of the articular disk and bilateral pars defect.

divedoc94, it's good that the neurologists don't see nerve damage.
You might ( I would) send the MRI CD to several orthopedic surgeons. Find at least one who does minimally invasive surgeries. You may be able to have repair of the pars. With repair to the pars the disc might heal on it's own.
Unroofing of the disc means that the disc has separated from the vertebral body. In the video below the disc has separated and is herniated. Yours disc may not be herniated, and may be simply pressing against the spinal cord in certain positions or with certain weight.
You might look at artificial discs. You may be able to avoid fusion.
I'd consider surgery because spondylolisthesis is progressive as is disc disease and either can eventually damage the spinal nerves.
Grade 1 anterolisthesis increases with forward bending which we never do in an MRI tunnel.
I hope you have luck.
https://cantorspinecenter.com/conditions/pars-defect/#:~:text=Direct%20Repair%20of%20the%20Pars,normal%20motion%20of%20the%20spine.

@divedoc94
In addition to what @gently recommended, you may want to have a cervical spine MRI to see if you have any compression there. Cervical compression can impact your leg strength and it is not picked up in an EMG/nerve conduction study. My orthopedic spine specialist told me spine issues are not measured by EMG and you could have a “normal” EMG but compressed spinal cord which happened to me. I just had a “normal” EMG but have a herniated C6-C7 disc pressing on my spinal cord and causing weakness in hips/legs, especially when standing up from seated position, going up stairs, and lifting leg up to put on pants.

The neurologist I’m seeing now is sending me for a cervical and thoracic MRI so we’ll see what that shows. I do feel like my weakness is starting to get worse with exercise as well as starting to get some pain when I try and train legs.

I have same lower extremity issues bilateral and symmetrical. Doctors thought my L3/4 and L4/L5 stenosis was causing that. Had both operated on in 2016 and 2021 but never resolved issues. Recently got another opinion from a new Neurosurgeon that ordered a cervical MRI. I only had very mild neck issues up until recently the burning at neck has started to increase.
MRI showed C5 C6 C7 major cord compression and could be cause of the funicular Pain syndrome I may be showing.
Will be meeting with him shortly to discuss ACDF procedure,

I got my cervical MRI report back today:
C2-C3: Left foraminal disc herniation indenting left C3 nerve root

C4-C5: Right paracentral herniated disc without neural compression

C5-C6: Right central disc herniation indenting right C6 nerve roots (annular fissure related edema)

C6-C7: Left paracentral herniated disc without neural compression

@divedoc94 I see from your report you have some disc herniations and one shows inflammation . When that happens, it can cause bone spurs to grow as your body tries to stabilize the spine. That makes it worse when you have bone compression on nerves. Do you have a good spine specialist ? You may want to get several opinions. From your symptoms with weakness and this report, I think surgery will be advised. I am a cervical spine patient with a C5/C6 fusion.

Neurologist said he doesn’t have an explanation for why I have the weakness, asked about the cervical MRI he said I had some things going on but not that would explain the leg weakness and doesn’t know what he can do for me and is putting me in for a referral for a neuromuscular clinic, now I just have to hope that my military insurance will approve it.

@divedoc94 Your neurologist is missing your diagnosis. This happened to me. Cervical spine issues can absolutely cause leg weakness. The para central disc herniations that you have are pressing on your spinal cord. I know it says without compression, but just touching the spinal cord can cause malfunction. The spinal cord has to move and shift as it floats in the fluid of the central canal. Imagine a rope inside a garden hose. If you bend the hose, that rope needs to move, and it can get tethered and compressed. That big bundle of nerve cells that is the spinal cord is like a giant cable of wires, and if you damage one wire in it, you aren't sure which one, it could be any of them. All of the nerves have to travel from your brain down the entire length of the cord to get to your legs.

I think a neuro muscular clinic is going to waste your time because they are guessing and don't know the cause. Often they do physical therapy, and if it fails to help, it demonstrates a need for surgery. You need a proper diagnosis and link to your symptoms.

Here is some medical literature that changed my medical journey. What I did with this, was to contact a surgeon with the literature and my imaging and ask if my case was like this. That lets them figure it out with all of that information, but make sure to ask it as a question because their job is to evaluate and diagnose. This is easily missed by many spine surgeons, but the good ones will recognize it. My recommendation is find a good spine surgeon for an opinion. They may have you see another neurologist because they like to work with certain ones, but a spine surgeon is who you need.

Eur Spine J
. 2010 Oct 13;20(Suppl 2):217–221. doi: 10.1007/s00586-010-1585-5
Cervical cord compression presenting with sciatica-like leg pain
https://pmc.ncbi.nlm.nih.gov/articles/PMC3111492/
If they can't figure out the cause of the malfunction, and link it to your imaging, they probably won't help you. I had to waste 2 years seeing 5 surgeons for opinions before I found this literature and with it, I found a good surgeon who helped me. He was at Mayo.