Use of Multimodality Intraoperative Neuromonitoring in Tethered Cord Syndrome – Experience from a Tertiary Care Center

Detethering of the spinal cord is done in nearly all cases of tethered cord syndrome (TCS), which can damage nerve roots, and hence, there is a need to identify filum terminale during surgery. Multimodality intraoperative neuromonitoring (IONM) may be useful in this regard to prevent postoperative morbidity. Twenty-six patients (13 males and 13 females, age range: one year to 56 years) with TCS were recruited for the study. Triggered electromyography (t-EMG), transcranial motor evoked potential (TcMEP) and free-running electromyography (f-EMG) were used in the study on a case-to-case basis. Warning criteria were followed according to the standard guidelines. Nerve roots and filum terminale were successfully identified and detethered in all cases. There was no new postoperative deficit seen. Transcranial motor evoked potentials did not change during surgery and no new limb weakness was seen in any of the investigated cases. Triggered EMG successfully helps in identifying nerve roots and filum terminale, while TcMEP is a good prognostic indicator of motor viability. Multimodality IONM use during tethered cord surgery should be encouraged to prevent postoperative deficits.