There is increasing evidence for the use of biomarkers, such as Neurofilament Light Chain (NfL), as clinical indicators for nerve lesions in the peripheral nervous system. Usually, this has been described in patients with diabetic neuropathy, Charcot-Marie-Tooth disease, or Guillain-Barre syndrome. Nonetheless, the potential value of NfL as a screening method for other conditions, such as Cauda Equina Syndrome (CES), is unknown. CES is associated with lumbar disc herniation compressing the roots of the cauda equina, causing bladder, bowel, and sexual function in patients.  The diagnosis is based on clinical examination and MRI, while the management of CES considers decompressive surgery. Since there are no biomarkers available to help in the initial screening of patients with CES, here we conduct a preliminary study in which we compare the serum concentrations of NfL in patients with suspected CES who have MRI positive, negative and unclear findings.