Background: The clinical tethered cord syndrome (TCS) can become symptomatic during adulthood, known as adult tethered cord syndrome (ATCS). Distinguishing ATCS from neurogenic claudication attributed to lumbar spinal stenosis may pose a clinical challenge.
Case Description: A 66-year-old male with an underlying complex occult spinal dysraphism (OSD) presented with new onset of lower back and bilateral leg pain plus neurogenic claudication. Magnetic resonance imaging documented OSD, and lumbar spinal stenosis (LSS) attributed to a supplementary midline muscle. Following decompressive surgery for LSS without untethering the ATCS, the patient's symptoms resolved.
Conclusion: A patient with OSD and ATCS with LSS due to a supplementary midline muscle presented with new onset of neurogenic claudication. Surgical decompression of the LSS by removing the supplementary midline muscle resolved patients' symptoms.