• Is NF-L in CSF Lumbal Puncture a reliable BioMarker?

    Posted by rony-ramaekers on November 26, 2021 at 3:07 pm

    Hi Everyone,

    I dare to ask this question over here in the forum, not to bother someone but because I know there is a lot of knowledge in this community.

    My story started in August 2021.  My leg felt a little weird, and weak, and a few weeks later I started to have widespread fasciculations in my entire body.  I got trouble swallowing, coughing and my upperarms, especially my right on became very small as my muscles (coming from my shoulder) were wasted.  I also noticed some weakness over there.

    I was send to a neurologist who did a basic neurologic Exam, and an EMG of the four limbs and the tongue.  This came back clean.  Also bloodwork, CT’s and MRI (Spine and Brain) were done, nothing wrong.

    Because my symptoms were still there and I’m pretty scared the neurologist proposed to do a lumbal puncture with some kind of Neurofilament marker.  This was done 6 weeks after my very first symptoms.

    The results came back extremely low

    NFL : 134 pg/ml. (must be lower than 1227)

    PNH : 115 pg/ml (must be lower than 750)

    Based on this results my neurologist closed the case.  No ALS!


    Do I have to search for a second opinion in this case, because I still got all the symptoms?

    Is this biomarker test a reliable test when done this early in the process?  Or is it possible that the puncture was done so early that Neurofillaments were not elevated yet?  After all, it was done 6 weeks after my very first subtile symptoms.

    The values a looking also extremely low to me, lower than normal.. Maybe something went wrong in the test, which seems impossible.

    I want to thank everybody already for all the comments on my post.


    marykg replied 1 year, 8 months ago 7 Members · 6 Replies
  • 6 Replies
  • cmdgb6gmail-com

    January 11, 2022 at 1:46 pm

    Hi Rony. I saw your post about neurofilament testing of spinal fluid. I actually just posted that question wondering if good for diagnosis. Have you had any luck getting a diagnosis yet? I have a Dr appointment tomorrow and will ask the neuromuscular Dr. Did insurance pay for it? Best wishes to you, Carol

  • bakereld

    January 11, 2022 at 2:40 pm

    I suggest a second opinion and if you have the means I would go to Mass general .  Fasciculations are a hall mark of ALS. no other disease causes them

  • johnw

    January 11, 2022 at 4:18 pm

    Hi Rony
    You might find that a muscle biopsy where your muscle function is reduced to help make the determibation. That was instrumental for me getting the ALS diagnosis after 2 years of EMG and othet tests.
    Best Wishes

  • jacky-clarke

    January 12, 2022 at 12:28 am

    Hi Rony, do you have any problems with your thumb and forefinger . It’s the pincer muscles that become wasted and cause ‘split hand syndrome ‘. A most definite marker for ALS. Also ‘drop foot is another classic symptom. It took 3 neurologists to finally diagnose me with ALS.

    All the best



  • richard-maloon

    January 12, 2022 at 12:34 am

    Do I have to search for a second opinion in this case, because I still got all the symptoms?



  • marykg

    January 12, 2022 at 4:45 am

    Highly suggest you go to an ALS Clinic such as Mayo, Johns Hopkins or VCU.
    Don’t give up.  There is someone out there who will help you.

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