Thoracic Disc Herniation in a Patient With Tethered Cord and Lumbar Syringomyelia and Diastematomyelia Magnetic Resonance Imaging and Neurophysiological Findings

Study Design. Case report. Objective. To describe the diagnostic challenges in a patient suffering from thoracic disc herniation (TDH) and spina bifida complicated by multiple lumbar spinal cord abnormalities, i.e., tethered cord, lumbar syringomyelia, and diastematomyelia. Summary of Background Data. Advances in neuroimaging, i.e., magnetic resonance imaging, increase the sensitivity to disclose both clinically relevant but also other spine and spinal cord abnormalities. TDH accounts for less than 1% of all surgically treated disc herniations. Syringomyelia and diastematomyelia are comparably rare and present with varying degrees of spinal cord dysfunction. Methods. A 54-year-old women presented with progressive pain and sensorimotor symptoms in the lower back and limbs. Neurologic examination revealed lower limb spastic motor deficits and spinal ataxia. Magnetic resonance imaging revealed a T6-T7 disc herniation, with spinal cord signal change in addition to a spina bifida with sacral tethered cord, lumbar syringomyelia, and diastematomyelia. Combined neurophysiological testing identified a neurologic lesion in the mid thoracic cord, with normal lower limb nerve conduction and reflex recordings, but pathologic somatosensory-evoked potential and T6 paravertebral electromyography. Results. The patient was diagnosed with a clinically relevant T6-T7 disc herniation and underwent successful surgical decompression resulting in electrophysiological improvements. Conclusion. This unique case highlights the value of electrophysiology in the evaluation of a complex spinal disorder in a patient suffering from acquired TDH in the presence of extensive congenital spine and spinal cord abnormalities. Clinical symptoms and signs can be complemented by neurophysiological techniques to improve diagnostic accuracy and improve the basis for treatment recommendations. In cases involving multiple spinal abnormalities, a comprehensive neurophysiological assessment beyond paravertebral electromyography studies, including nerve conduction and somatosensory-evoked potential recordings, is recommended to assist in confirming the diagnosis.