Transcranial motor evoked potential waveform changes in corrective fusion for adolescent idiopathic scoliosis

Abstract

<jats:sec> <jats:title>OBJECTIVE</jats:title> <jats:p>Corrective surgery for spinal deformities can lead to neurological complications. Several reports have described spinal cord monitoring in surgery for spinal deformity, but only a few have included patients younger than 20 years with adolescent idiopathic scoliosis (AIS). The goal of this study was to evaluate the characteristics of cases with intraoperative transcranial motor evoked potential (Tc-MEP) waveform deterioration during posterior corrective fusion for AIS.</jats:p></jats:sec> <jats:sec> <jats:title>METHODS</jats:title> <jats:p>A prospective database was reviewed, comprising 68 patients with AIS who were treated with posterior corrective fusion in a prospective database. A total of 864 muscles in the lower extremities were chosen for monitoring, and acceptable baseline responses were obtained from 819 muscles (95%). Intraoperative Tc-MEP waveform deterioration was defined as a decrease in intraoperative amplitude of ≥ 70% of the control waveform. Age, Cobb angle, flexibility, operative time, estimated blood loss (EBL), intraoperative body temperature, blood pressure, number of levels fused, and correction rate were examined in patients with and without waveform deterioration.</jats:p></jats:sec> <jats:sec> <jats:title>RESULTS</jats:title> <jats:p>The patients (3 males and 65 females) had an average age of 14.4 years (range 11–19 years). The mean Cobb angles before and after surgery were 52.9° and 11.9°, respectively, giving a correction rate of 77.4%. Fourteen patients (20%) exhibited an intraoperative waveform change, and these occurred during incision (14%), after screw fixation (7%), during the rotation maneuver (64%), during placement of the second rod after the rotation maneuver (7%), and after intervertebral compression (7%). Most waveform changes recovered after decreased correction or rest. No patient had a motor deficit postoperatively. In multivariate analysis, EBL (OR 1.001, p = 0.085) and number of levels fused (OR 1.535, p = 0.045) were associated with waveform deterioration.</jats:p></jats:sec> <jats:sec> <jats:title>CONCLUSIONS</jats:title> <jats:p>Waveform deterioration commonly occurred during rotation maneuvers and more frequently in patients with a larger preoperative Cobb angle. The significant relationships of EBL and number of levels fused with waveform deterioration suggest that these surgical invasions may be involved in waveform deterioration.</jats:p></jats:sec>

Loss of temperature and pain sensation as risk marker of neurological complications in surgical correction of severe spinal deformity

“…Ряд авторов выделяют следующие возможные причины неврологических осложнений при кор-рекции деформаций позвоночника: 1) врожден-ный сколиоз; 2) сколиоз с гиперкифозом; 3) угол деформации > 90°; 4) комбинированные методы хирургии; 5) ревизионная хирургия; 6) уменьше-ние перфузии спинного мозга вследствие гипо-тензии или значительной кровопотери, сдавления сосудов; 7) дооперационный неврологический де-фицит [8,9,14]. Процедуры, связанные с более высоким риском, включают остеотомию и кор-рекцию кифоза [7,9,28].…”

“…В настоящее время применение моторных транскраниально вызванных потенциалов (МВП) является важным составным элементом «золото-го стандарта» ИОНМ при коррекции деформаций позвоночника [8,[11][12][13][14][15], поскольку они чрезвы-чайно чувствительны к изменению кровотока в спинном мозге из-за гипотонии или сдавления (поражения) сосудов [8,9]. Изменения параметров МВП в ответ на хирургическую агрессию нередко обнаруживаются раньше, чем реакция соматосен-сорных вызванных потенциалов, что способствует более быстрой идентификации надвигающегося повреждения спинного мозга [8].…”

Intraoperative Neurophysiological Monitoring for Spinal Fusion

“…In scoliosis correction surgeries, as there is a high number of levels, there is a real risk of occurrence of poor positioning of the pedicle screws inserted, even with the aid of intraoperative electromyographic stimulation. 36 Kobayashi et al 23 studied the characteristics of cases with intraoperative transcranial motor-evoked potential waveform deterioration (defined as a decrease in intraoperative amplitude 70% of the control waveform) during posterior corrective fusion for adolescent idiopathic scoliosis. Waveform deterioration commonly occurred during rotation maneuvers and more frequently in patients with a larger preoperative Cobb angle.…”

The Relationship between the Angle of Curvature of the Spine and SEMG Amplitude of the Erector Spinae in Young School-Children

“…This pathology applies, in particular, to the broadly understood postural system [5]. It affects, most likely, the system of deep back muscles (erector spinae), on the growing spine of a child with individually variable and multifactorial susceptibility to distortion [6]. Progression of scoliosis is associated with growth and biomechanical factors.…”