The impact and value of uni- and multimodal intraoperative neurophysiological monitoring (IONM) on neurological complications during spine surgery: a prospective study of 2728 patients

PurposeWe compared the value of different uni- and multimodal intraoperative neurophysiological monitoring (IONM) methods on the detection of neurological complications during spine surgery.MethodsIONM data derived from sensory spinal and cortical evoked potentials combined with continuous electromyography monitoring, motor evoked potentials and spinal recording were evaluated in relation to subsequent post-operative neurological changes. Patients were categorised based on their true-positive or true-negative post-operative neurological status.ResultsIn 2728 consecutive patients we had 909 (33.3%) IONM alerts. We had 8 false negatives (0.3%) with post-operative radicular deficit that completely recovered within 3months, except for one. There was no false negative for spinal cord injury. 107 were true positives, and 23 were false positives. Multimodal IONM sensitivity and specificity were 93.0% and 99.1%, respectively. The frequency of neurological complications including minor deficits was 4.2% (n=115), of which 0.37% (n=10) were permanent. Analysis of the single IONM modalities varied between 13 and 81% to detect neurological complications compared with 93% when using all modalities.ConclusionMultimodal IONM is more effective and accurate in assessing spinal cord and nerve root function during spine surgeries to reduce both neurological complications and false-negative findings compared to unimodal monitoring. We recommend multimodal IONM in all complex spine surgeries. [GRAPHICS] .