Tethered Cord Syndrome–A Study of the Short-Term Effects of Surgical Detethering on Markers of Neuronal Injury and Electrophysiologic Parameters

Abstract

Several studies have assessed clinical and radiologic outcomes after detethering of the cord for tethered cord syndrome (TCS). However, no data regarding the impact of detethering on the metabolism or electrophysiologic functioning of the cord are available. The aim of this study was to assess the changes in the cerebrospinal fluid (CSF) levels of markers of neuronal injury and alterations in the electrophysiologic functioning of the spinal cord after detethering. This prospective study included patients with congenital TCS. Patients underwent clinical assessment, magnetic resonance imaging, somatosensory evoked potentials (SSEP) study, and CSF biochemical analysis (to estimate lactate, glial fibrillary acidic protein, and S100B levels), before and 3 months after surgery. Clinical and radiologic outcomes were assessed. We studied changes in biochemical and electrophysiologic parameters before and after detethering as surrogate markers for the effects of this intervention. Twenty-one patients were recruited over 2 years. Detethering led to clinical improvement in 75% of patients with motor deficits, 60% of patients with bladder symptoms, and 50% of patients with gait problems. At 3 months follow-up, 43% (median) of the preoperative vertical tethering was found to be corrected. There was significant reduction in CSF lactate, glial fibrillary acidic protein, and S100B levels as well as a significant decrease in the latencies of the SSEP waves 3 months after surgery. Surgical detethering led to a reduction in the CSF levels of the markers of anaerobic metabolism and neuronal injury. There was also a reduction in the latencies of the SSEP waves, indicating better electrophysiologic functioning of the cord.