Abstract Background Early postoperative neurological deterioration remains one of the most serious complications after thoracic spine surgery. Conventional preoperative risk assessment relies mainly on clinical and imaging variables, whereas the incremental value of electrophysiological indicators has not been fully defined. Dermatomal somatosensory evoked potentials (DSEP) may provide segment-specific functional information beyond structural imaging. This study aimed to develop and internally validate a preoperative prediction model incorporating electrophysiological parameters for early postoperative neurological deterioration after thoracic decompression surgery. Methods A total of 508 patients who underwent thoracic decompression surgery were retrospectively included. Candidate predictors comprised age, preoperative Japanese Orthopaedic Association (JOA) score, number of compressed levels, T2-weighted intramedullary signal change, and DSEP-derived variables including maximal N1 latency, minimal amplitude, and number of abnormal DSEP sites. Four multivariable logistic regression models were constructed: a clinical model, a clinical + imaging model, a clinical + electrophysiological model, and a combined model. Internal validation was performed using stratified five-fold cross-validation. Model performance was assessed using the area under the receiver operating characteristic curve (AUC), calibration metrics, Brier score, decision curve analysis, and bootstrap-based optimism correction. Results Among the 508 patients, 107 (21.1%) met criteria for early postoperative neurological deterioration. In the combined multivariable model, T2-weighted intramedullary signal change (OR 1.734, 95% CI 1.071–2.809, P = 0.025) and the number of abnormal DSEP sites (OR 1.687, 95% CI 1.338–2.128, P < 0.001) were independently associated with early postoperative neurological deterioration, whereas maximal N1 latency showed a borderline association (OR 1.092, 95% CI 0.997–1.196, P = 0.058). Cross-validated discrimination was limited for the clinical model (AUC 0.543, 95% CI 0.478–0.610) and improved modestly for the clinical + imaging model (AUC 0.596, 95% CI 0.536–0.659). Incorporation of electrophysiological variables substantially improved performance in the clinical + electrophysiological model (AUC 0.713, 95% CI 0.655–0.766), while the combined model showed the highest overall performance (AUC 0.715, 95% CI 0.658–0.770). Models containing electrophysiological variables also demonstrated better calibration and lower Brier scores. Bootstrap optimism correction showed only modest optimism across models. Conclusions Preoperative DSEP abnormalities, particularly a greater burden of abnormal DSEP sites, may improve risk stratification for early postoperative neurological deterioration after thoracic spine surgery. Models incorporating electrophysiological variables showed better discrimination, calibration, and clinical net benefit than models based on clinical variables alone. These findings support the potential role of preoperative DSEP as a functional adjunct to conventional assessment, but external validation is required before broader clinical implementation.

We aim to explore the effects of the erector spinae plane block (ESPB) technique combined with dexmedetomidine administered systemically on somatosensory- and/or motor- evoked potential (SSEP and/or MEP) during surgical correction for adult spinal deformity (ASD). 88 patients were randomly allocated to two groups: the propofol-remifentanil based total intravenous anesthesia (TIVA) group (Group T), and the dexmedetomidine group (Group DE), which received dexmedetomidine intravenously at a rate of 0.5 μg kg-1 h-1 as an adjuvant to TIVA, along with bilateral bi-level single-shot ESPB using 0.2% ropivacaine. Bilateral bi-level single-shot ESPB was performed in Group DE. The depth of anesthesia was adjusted by varying the propofol infusion rate based on the bispectral (BIS), which was maintained between 40 and 60. Mean arterial pressure was maintained between 70 and 85 mmHg. In Group T, within-group analysis presented an inhibitory effect on MEP amplitude after surgical correction, which persisted for 30 min when compared to the baseline values. Between-group analysis demonstrated a statistically significant decrease in MEP amplitude after surgical correction, lasting for 30 min in Group T compared to Group DE. However, no significant differences were observed in SSEP. No patients experienced serious postoperative side effects. Dexmedetomidine adjuvant to TIVA, then followed by preemptive analgesia with ESPB does not exert inhibitory effects on SSEP/MEP in ASD surgery. However, suppressive effects on MEP amplitude were observed and persisted for at least 30 min in patients who receive only TIVA. Importantly, no post-operative side effects were observed in either group.Clinical Trial Registration: Chinese Clinical Trial Registry.cn; Identifier: ChiCTR2200057123.

We aim to determine the surgical outcomes in patients with thoracic ossification of the posterior longitudinal ligament (OPLL) and/or ossification of the ligamentum flavum (OLF) who experienced intraoperative somatosensory- and/or motor-evoked potential (SSEP and/or MEP) changes. Patients who diagnosed with OPLL and/or OLF were identified. SSEP/MEP signals were acquired at two time-points: (1) during the maximal signal change and (2) 20 min after the change. Manual muscle testing (MMT) and the modified Japanese Orthopedic Association Scoring System (mJOA) were obtained to assess perioperative spinal neurological function. Of the 165 eligible patients, 104 experienced SSEP/MEP changes. These patients were stratified into two subgroups: 22 patients exhibited persistent signal changes, while 82 patients showed partial or complete signal recovery within 20 min after the maximum change. Patients with reversible SSEP/MEP changes had comparable surgical outcomes to those in the no-change group, including estimated blood loss ( 463 ±145 ml vs. 486±162 ml, p = 0.47) and operative time (205 ± 28 min vs. 213 ± 27 min, p = 0.81). Furthermore, postoperative spinal neurological function in patients with reversible change was similar to those of the no-change group in terms of short-term postoperative motor deficit (PMD) cases (reversible group: n = 4; no-change group: n = 2; p = 0.64 ) and long-term mJOA recovery ratio (RR) (reversible change group: 29.19

We aim to investigate the spinal neurological outcomes in patients who have undergone surgery for thoracic spinal stenosis (TSS) and to identify high-risk factors for poor spinal neurological prognosis. Patients were categorized into four subgroups based on TSS causes: thoracic disk herniation (TDH), ossification of the posterior longitudinal ligaments (OPLL), ossification of the ligamentum flavum (OLF), and OPLL + OLF. The following data were collected: (1) demographic and clinical data; (2) neurological evaluation; and (3) neurophysiological evaluation by combining somatosensory- and motor- evoked potential (SSEP and MEP) baseline at both legs. The spinal neurological function was assessed by modified Japanese Orthopedic Association (mJOA) score at three time-point: before surgery, one-month and six-month after the surgery; Univariate and multivariate logistic regression analyses were performed to identify independent high-risk factors associated with poor spinal neurological prognosis. A total of 236 patients were diagnosed with TSS. The mean mJOA scores before and six months after the surgery were 7.0 and 7.9, respectively. The number of patients with declined spinal neurological outcomes during the short- and long- term follow-ups were 17 and 8, respectively. Based on multivariate logistic analysis, risk factors for poor spinal neurological prognosis were as follows: preoperative severe myelopathy [OR = 5.65, 95

BACKGROUND CONTEXT:Although intraoperative neurophysiological monitoring (IONM) has been widely recognized and used in spine surgery, its characteristics vary for different types of spinal disorders, necessitating the development of tailored monitoring strategies. Cervical spinal stenosis presents complex clinical symptoms and carries significant surgical risks, creating a critical need to clarify the monitoring features, alert patterns, and their relationship with outcomes in such surgeries. A comprehensive assessment and the development of a refined IONM monitoring plan throughout the perioperative period is an important direction for future research. PURPOSE:This study aims to investigate the influencing factors of intraoperative neurophysiological monitoring (IONM) alarm events in patients with cervical spinal canal stenosis and to evaluate the predictive value of different IONM alarm patterns on neurological recovery following decompression surgery. DESIGN:Retrospective study. PATIENT SAMPLES:This analysis included 1,622 patients who underwent cervical spinal canal decompression surgery and had complete IONM monitoring data between February 2017 and December 2022. OUTCOME MEASURES:The preoperative and postoperative neurological status of the patients was assessed using the modified Japanese Orthopaedic Association (mJOA) score. The primary IONM alarm indicators included somatosensory evoked potentials (SSEP) and transcranial motor evoked potentials (MEP), compared to the preoperative baseline. METHODS:Logistic regression was employed to analyze the correlation between preoperative diagnostic risk factors and intraoperative alarm events. Additionally, a multifactorial interaction analysis was performed to determine the relationship between IONM changes and the reversibility of alarms with the six-month mJOA recovery rate. RESULTS:Preoperative diagnoses of the ligamentum flavum hypertrophy and/or ossification of the posterior longitudinal ligament, combined with an mJOA score <12, were identified as high-risk factors for intraoperative alarms. The sensitivity of alarms in the high-risk group was 100%, with a positive predictive value of 90.6%; in the low-risk group, the sensitivity was 91.7%, with a positive predictive value of 40.74%. Variance analysis indicated that the mJOA improvement rate at six months was significantly lower in patients with irreversible IONM alarms compared to those with reversible alarms. Interaction analysis suggested that the reversibility of intraoperative alarm events was a principal predictor of postoperative outcomes, while risk factors for alarms had predictive value only in patients with irreversible alarms. CONCLUSIONS:In patients with cervical spinal canal stenosis caused by disc degeneration, the presence of ligamentum flavum hypertrophy, ossification of the posterior longitudinal ligament, and preoperative mJOA scores <12 are significant high-risk factors for intraoperative alarms. The sensitivity and positive predictive value of intraoperative alarms in the high-risk group were significantly higher than those in the low-risk group. Moreover, patients with irreversible alarms exhibited poorer prognoses compared to those with reversible alarms, and preoperative alarm risk factors should not be considered independent predictors of patient outcomes.

Background: Intraoperative hypotension (IOH) is a recognized contributor to changes in motor evoked potential (MEP) during spinal surgeries. Additionally, it is essential to precisely define IOH across different surgical phases. However, there is limited data on optimal IOH thresholds for predicting MEP changes in thoracic ossification of the posterior longitudinal ligament (OPLL) and/or ossification of the ligamentum flavum (OLF) surgery. We aim to determine the IOH thresholds for predicting MEP changes during surgical treatment for OPLL and/or OLF based on different surgical phase. Methods: Data collected included demographic information, surgical details, mean arterial pressure (MAP) values, and MEP signals. A receiver operating characteristic (ROC) curve was employed to determine the MAP thresholds. A comparative analysis was performed to evaluate IOH episodes occurring during predecompression versus postdecompression surgical phases, specifically in the early and later stages. Additionally, a multivariate logistic regression analysis was conducted to assess the association between surgical variables and MEP change. Results: The MAP thresholds for predicting changes in MEP at the early surgical stage were determined as follows: 70 mmHg for patients with combined OPLL and OLF, 66 mmHg for OPLL patients, and 65 mmHg for OLF patients. However, it is recommended that MAP at the later surgical stage should be elevated to exceed 75 mmHg, 73 mmHg, and 71 mmHg in patients diagnosed with combined OPLL and OLF, OPLL, and OLF, respectively. A stronger correlation was observed between MAP variability ratio and MEP amplitude reduction ratio (ARR) during postdecompression surgical phase. At the early surgical stage, the administration of ephedrine bolus was identified as a risk factor for predicting MEP change (odds ratio [OR]=1.13, p<.01). At the later stage, the risk-factors included ephedrine bolus (OR=1.09, p<.01), estimated blood loss (per 100 mL) (OR=1.23, p=.02), and patients with combined OPLL and OLF (OR=12.12, p<.01). Conclusions: We determined cutoff values for MAP to predict changes in MEP in patients undergoing surgical treatment for OPLL and/or OLF based on different surgical phases. Compared to the early surgical stage, patients exhibit less tolerance to IOH at the later surgical stage. A stronger correlation was observed between the MAP variability ratio and MEP ARR at the later surgical stage. Additionally, we identified surgical factors that are associated with a higher probability of MEP change.

BACKGROUND The objective of this study was to develop and validate machine learning (ML) algorithms to predict the 30-day and 6-month risk of deteriorating functional status following surgical treatment for thoracic spinal stenosis (TSS). We aimed to provide surgeons with tools to identify patients with TSS who have a higher risk of postoperative functional decline. MATERIAL AND METHODS The records of 327 patients with TSS who completed both follow-up visits were analyzed. Our primary endpoint was the dichotomized change in the perioperative Japanese Orthopedic Association (JOA) score, categorized based on whether it deteriorated or not. The models were developed using Naïve Bays, LightGBM, XGBoost, logistic regression, and random forest classification models. The model performance was assessed by accuracy and the c-statistic. ML algorithms were trained, optimized, and tested. RESULTS The best-performing algorithms for predicting functional decline at 30 days and 6 months after TSS surgery were XGBoost (accuracy=88.17%, c-statistic=0.83) and Naïve Bays (accuracy=86.03%, c-statistic=0.80). Both algorithms presented good calibration and discrimination in our testing data. We identified several significant predictors, including poor quality of intraoperative SSEP/MEP baseline, poor quality of preoperative SSEP, duration of symptoms, operated level, and motor dysfunction of the lower extremity. CONCLUSIONS The best-performing algorithms for predicting functional decline at 30 days and 6 months after TSS surgery were XGBoost (accuracy=88.17%, c-statistic=0.83) and Naïve Bays (accuracy=86.03%, c-statistic=0.80). Both algorithms presented good calibration and discrimination in our testing data. We identified several significant predictors, including poor quality of intraoperative SSEP/MEP baseline, poor quality of preoperative SSEP, duration of symptoms, operated level, and motor dysfunction of the lower extremity.

BACKGROUND CONTEXT: Thoracic spinal stenosis (TSS) is secondary to different pathologies that differ in clinical characteristics and surgical outcomes.PURPOSE: This study aimed to determine the optimal warning thresholds for combined somatosensory-evoked potentials (SSEP) and motor-evoked potentials (MEP) for predicting postoperative neurological deterioration in surgical treatment for TSS based on different pathologies. Additionally, we explored the correlation between SSEP/MEP monitoring and postoperative spinal neurological function.STUDY SETTING: Retrospective study.PATIENT SAMPLE205 patients.OUTCOME MEASURESWe obtained perioperative modified Japanese Orthopedic Association (mJOA) scores to assess spinal neurological function.METHODS: The data collected in this study included demographic data, intraoperative neurophysiological monitoring (IONM) signals, and perioperative neurological function assessments. To determine the optimal IONM warning threshold, a receiver operating characteristic (ROC) curve was used. Additionally, Pearson correlation analysis was conducted to determine the correlation between IONM signals and clinical neurological conditions.RESULTS: A total of 205 consecutive patients were eligible. Forty-one patients had thoracic disc herniation (TDH), 14 had ossification of the posterior longitudinal ligament (OPLL), 124 had ossification of the ligamentum flavum (OLF), and 26 had OPLL+OLF. The mean mJOA scores before surgery and 3 months after surgery were 7.0 and 7.9, respectively, resulting in a mean mJOA recovery rate (RR) of 23.1%. The average postoperative mJOA RRs for patients with TDH, OPLL, OLF, and OPLL+OLF were 24.8%, 10.4%, 26.8%, and 11.2%, respectively. Patients with OPLL+OLF exhibited a more stringent threshold for IONM changes. This included a lower amplitude cutoff value (a decrease of 49.0% in the SSEP amplitude and 57.5% in the MEP amplitude for short-term prediction) and a shorter duration of waveform change (19.5 minutes for SSEP and 22.5 minutes for MEP for short-term prediction). On the other hand, patients with TDH had more lenient IONM warning criteria (a decrease of 49.0% in SSEP amplitude and 77.5% in MEP amplitude for short-term prediction; durations of change of 25.5 minutes for SSEP and 32.5 minutes for MEP). However, OPLL patients or OLF patients had moderate and similar IONM warning thresholds. Additionally, there was a stronger correlation between the SSEP amplitude variability ratio and the JOA RR in OPLL+OLF patients, while the correlation was stronger between the MEP amplitude variability ratio and the JOA RR for the other three TSS pathologies.CONCLUSIONS: Optimal IONM change criteria for prediction vary depending on different TSS pathologies. The optimal monitoring strategy for prediction varies depending on TSS pathologies.

Background context Combined somatosensory- and motor-evoked potential (SSEP and MEP) changes for predicting prognosis in thoracic spinal surgery have been variably reported. Purpose We aimed to explore the validity of combined SSEP and MEP for predicting postoperative motor deficits (PMDs) in thoracic spinal decompression surgery (TSDS) and identify a relatively optimal neurophysiological predictor of PMDs in patients based on preoperative motor status. Study setting Retrospective study. Patient sample A total of 475 patients were analyzed. Outcome Measures A reduction in muscle strength by more than or equal to one manual muscle testing (MMT) grade postoperatively compared with the preoperative MMT grade was identified as PMDs. Postoperative motor deficits were detected by comparing the preoperative and postoperative physical examination findings in short- and long-term follow-up visits. Methods All patients were divided into two subgroups according to preoperative motor status. The following data were collected: (1) demographic data; (2) IONM (intraoperative neuromonitoring) data; and (3) postoperative motor outcomes. Binary logistic regression analysis was performed to assess the efficacy of IONM change to predict PMDs. A receiver operating characteristic curve (ROC) was used to establish optimal IONM warning criteria. Results Ninety-eight patients had severe preoperative motor deficits (Group S), and 377 patients did not (Group N). MEP and SSEP change was effective for predicting PMDs in the short term (p<.01) and long term (p<.01) for TSDS patients. In Group N, the cutoff values for predicting PMDs in the short term were a decrease of 65% in SSEP amplitude and 89.5% in MEP amplitude of the baseline value. Furthermore, the cutoff values for predicting PMDs in the short term were durations of change of 24.5 minutes for SSEP and 32.5 minutes for MEP. In Group S, however, the cutoff values for predicting PMDs in the short term were a decrease of 36.5% in SSEP amplitude and 59.5% in MEP amplitude of the baseline value. Moreover, the critical values for predicting short-term PMDs were durations of change of 16.5 minutes for SSEP and 17.5 minutes for MEP. Conclusions The optimal IONM changes for prediction vary depending on preoperative motor status. Combined SSEP and MEP are excellent for predicting PMDs in TSDS.

Purpose We aimed to investigate the value of intraoperative multi-channel recording of somatosensory evoked potentials (SSEPs) in patients undergoing posterior instrumentation surgery with fusion. Methods This study included 176 patients with scoliosis who underwent posterior correction surgery from January 2019 to June 2020. Among them, 88 patients underwent routine SSEPs monitoring via single-channel (Cz'-Fpz) cortical recording (control group), while the remaining 88 patients underwent multi-channel (Cz'-Fpz and C3'-C4') SSEPs monitoring in the cortex. Chi-square and Fisher’s exact tests were used to analyze the influence of age, spinal deformity classification, and Cobb angle on waveform differentiation and the success rate of SSEPs monitoring. Results Univariate analysis revealed that age, type of scoliosis, and Cobb angle exerted significant effects on the success rate of intraoperative SSEPs monitoring, and the SSEPs waveform differentiation rate was poorest among patients with congenital scoliosis. Intraoperative monitoring results indicated that the success rate of single-channel SSEPs monitoring was 90.9%, while that of multi-channel monitoring was 98.9% ( P < 0.05). Among the intraoperative alarm cases, the incidence of adverse events after single-channel SSEPs monitoring was 66.7%, while the incidence of adverse events after multi-channel SSEPs monitoring was only 28.6%. Conclusion Multi-channel cortical SSEPs monitoring can effectively and accurately evaluate the function of the posterior column of the spinal cord. Use of multi-channel SSEP monitoring may help to improve the success rate of monitoring and reduce the incidence of postoperative adverse events in patients with congenital scoliosis.

[目的]探讨多模式术中监测在脊柱侧弯手术患者脊髓及神经根功能评估中的应用价值.[方法]选取2019年1月至2022年1月西安市红会医院收治的90例脊柱侧弯手术患者,按照随机数字表法分为观察组和对照组,每组45例,两组均由同一监护团队进行术中神经监护,对照组采用单模式监护,观察组采用多模式神经电生理监测技术.比较两组围术期指标、日本骨科学会颈椎病疗效评定标准(JOA)评分、腰椎前凸角度、冠状面Cobb角,通过一致性分析体感诱发电位(SEP)、运动诱发电位(MEP)、自由肌电图(FEMG)单独及联合监测异常的效果.[结果]观察组45例患者中10例出现术中神经电生理监测报警,其中6例真阳性,4例因非手术因素导致的假阳性.两组手术时间、术中出血量、平均动脉压、引流管置管时间比较,差异无统计学意义(P＞0.05).与术前比较,两组术后冠状面Cobb角减少,JOA评分、腰椎前凸角度升高,差异有统计学意义(P＜0.05);两组术后JOA评分、腰椎前凸角度、冠状面Cobb角比较,差异无统计学意义(P＞0.05);SEP监测敏感度为0.833,特异性为0.923,准确率为0.911,阳性预测值为0.625,阴性预测值为0.973,Kappa=0.663;MEP监测敏感度为0.667,特异性为0.923,准确率为0.889,阳性预测值为0.571,阴性预测值为0.947,Kappa=0.551;FEMG监测敏感度为0.833,特异性为0.897,准确率为0.889,阳性预测值为0.56,阴性预测值为0.972,Kappa=0.603;多模式联合监测敏感度为1.000,特异性为0.897,准确率为0.911,阳性预测值为0.600,阴性预测值为1.000,Kappa=0.700.观察组神经系统并发症发生率低于对照组,差异有统计学意义(P＜0.05).[结论]多模式术中监测应用于脊柱侧弯手术中可有效降低患者术后神经系统并发症发生率,且一致性分析证实联合监测灵敏率较高,可及时预警神经损伤,提高手术安全性.

目的 探讨神经电生理与高频超声在肘管综合征诊断中的应用价值.方法 选取2020年1月至2021年12月西安市红会医院收治的70例肘管综合征患者作为观察组,选择同期我院30例健康体检者作为对照组.两组受检者均行神经电生理与高频超声检查.比较两组受检者的运动神经传导、感觉神经传导、尺神经指标.并以手术诊断结果为金标准,比较神经电生理、高频超声单独及联合检查对肘管综合征的诊断效果.结果 观察组患者肘上至肘下的运动传导速度(MCV),腕部至小鱼际肌、肘下至小鱼际肌、肘上至小鱼际肌的运动传导波幅(CMAP)及腕部至小指的感觉传导速度(SCV)明显小于对照组,差异均有统计学意义(P<0.05);观察组患者的尺神经前后径、左右径、横截面积(CSA)明显高于对照组,差异均有统计学意义(P<0.05),而两组受检者的腕部至小指的感觉传导波幅(SNAP)比较差异无统计学意义(P>0.05);观察组患者行第一骨间肌、小指展肌及尺侧腕屈肌肌电图检测静息状态时出现纤颤、正相电位的比例分别为50.00%、28.57%、15.71%,大力收缩时呈单纯相或单混相的比例分别为28.57%、15.71%、10.00%;对照组的各运动单位电位时限、波幅及相位均无异常.以手术诊断结果为金标准,神经电生理及高频超声分别及联合使用诊断肘管综合征的阳性预测值分别为95.24%(60/63)、95.00%(57/60)、98.51%(66/67),阴性预测值分别为42.86%(3/7)、50.00%(5/10)、33.33%(1/3).结论 神经电生理与高频超声在诊断肘管综合征中均具有一定应用价值,且两者联合检查对肘管综合征的诊断更具参考价值.

Background:Intraoperative neuromonitoring (IONM) has become an increasingly essential technique in spinal surgery. However, data on the diagnostic value of IONM in predicting impending postoperative neurological deficits (PONDs) for patients who underwent posterior decompression surgery for thoracic spinal stenosis (TSS) are limited. Furthermore, patients who are at the highest risk of waveform changes during the surgery remain unknown. Our purpose was to (1) assess the diagnostic accuracy of IONM by combining somatosensory-evoked potential (SSEP) with motor-evoked potential (MEP) in predicting PONDs for patients who underwent the surgery and (2) identify the independent risk factors correlated with IONM changes in our study population.Methods:A total of 326 consecutive patients who underwent the surgery were identified and analyzed. We collected the following data: (1) demographic and clinical data; (2) IONM data; and (3) outcome data such as details of PONDs, and recovery status (complete, partial, or no recovery) at the 12-month follow-up visit.Results:In total, 27 patients developed PONDs. However, 15, 6, and 6 patients achieved complete recovery, partial recovery, and no recovery, respectively, at the 12-month follow-up. SSEP or MEP change monitoring yielded better diagnostic efficacy in predicting PONDs as indicated by the increased sensitivity (96.30%) and area under the receiver operating characteristic (ROC) curve (AUC) value (0.91). Only one neurological deficit occurred without waveform changes. On multiple logistic regression analysis, the independent risk factors associated with waveform changes were as follows: preoperative moderate or severe neurological deficits (p = 0.002), operating in the upper- or middle-thoracic spinal level (p = 0.003), estimated blood loss (EBL) ≥ 400 ml (p < 0.001), duration of symptoms ≥ 3 months (p < 0.001), and impairment of gait (p = 0.001).Conclusion:Somatosensory-evoked potential or MEP change is a highly sensitive and moderately specific indicator for predicting PONDs in posterior decompression surgery for TSS. The independent risks for IONM change were as follows: operated in upper- or middle-thoracic spinal level, presented with gait impairment, had massive blood loss, moderate or severe neurological deficits preoperatively, and had a longer duration of symptoms.Clinical Trial Registration:[http://www.chictr.org.cn]; identifier [ChiCTR 200003 2155].

Background:The effect of a bolus dose of dexmedetomidine on intraoperative neuromonitoring (IONM) parameters during spinal surgeries has been variably reported and remains a debated topic.Methods:A randomized, double-blinded, placebo-controlled study was performed to assess the effect of dexmedetomidine (1 μg/kg in 10 min) followed by a constant infusion rate on IONM during thoracic spinal decompression surgery (TSDS). A total of 165 patients were enrolled and randomized into three groups. One group received propofol- and remifentanil-based total intravenous anesthesia (TIVA) (T group), one group received TIVA combined with dexmedetomidine at a constant infusion rate (0.5 μg kg−1h−1) (D1group), and one group received TIVA combined with dexmedetomidine delivered in a loading dose (1 μg kg−1in 10 min) followed by a constant infusion rate (0.5 μg kg−1h−1) (D2group). The IONM data recorded before test drug administration was defined as the baseline value. We aimed at comparing the parameters of IONM.Results:In the D2group, within-group analysis showed suppressive effects on IONM parameters compared with baseline value after a bolus dose of dexmedetomidine. Furthermore, the D2group also showed inhibitory effects on IONM recordings compared with both the D1group and the T group, including a statistically significant decrease in SSEP amplitude and MEP amplitude, and an increase in SSEP latency. No significance was found in IONM parameters between the T group and the D1group.Conclusion:Dexmedetomidine delivered in a loading dose can significantly inhibit IONM parameters in TSDS. Special attention should be paid to the timing of a bolus dose of dexmedetomidine under IONM. However, dexmedetomidine delivered at a constant speed does not exert inhibitory effects on IONM data.

Abstract Background The aim of this study was to assess the value of dermatomal somatosensory evoked potentials (DSEPs) and cortical somatosensory evoked potentials (SSEPs) in monitoring spinal cord function for patients with congenital scoliosis (CS). Methods This retrospective study reviewed the medical records of patients (n = 102) who underwent DSEP (T2-S1 dermatome), of whom 60 were normal subjects and 62 with congenital scoliosis. The study analyzed the latencies and peaks of N1-L, N1-R, P1-L and P1-R recorded by DSEPs of patients’ thoracolumbar dermatomes. To observe the incidence of abnormal DSEPs and SSEPs in CS patients and to analyze the difference in sensitivity and reliability between the two in the examination of scoliosis patients. SPSS 22.0 statistical software package was used to analyze the data, and χ2 test and correlation analysis were used to indicate that the difference was statistically significant, p < 0.05. Results Sixty two patients with CS were evaluated with total spine magnetic resonance imaging (MRI). Only 23 patients (37.09%) showed spinal cord malformations in the MRI findings. The DSEP recordings showed a relatively high sensitivity (97.8%) compared to the abnormality rate of SSEPs recordings, and the rates of waveform, latency and amplitude abnormalities were much higher in DSEPs recordings (36.6, 36.3, 24.8%) than in SSEPs recordings (3.2, 22.5, 14.5%). The abnormality rate of DSEP records with and without neurological symptoms was higher than the abnormality rate of SSEP records (100% vs 20, 96.2% vs 44.2%, p<0.05). And in 62 patients with CS, the rate of positive MRI (37.1%) was lower than that recorded by DSEP (79.6% / 57.9%). p < 0.05. Conclusion DSEPs are more sensitive to microscopic posterior column dysfunction in patients with CS that cannot be detected by either radiology or routine clinical examination. Preoperative DSEPs assessment is recommended as a baseline examination for intraoperative monitoring and comparison with the postoperative situation. DSEPs recording complements the information obtained from routine clinical and radiological evaluation.

Objective. This study aimed to evaluate the safety and efficacy of the fixation of transforaminal sacral fractures using TiRobot-assisted transiliac-transsacral (TITS) screws under multimodal neuroelectrophysiological monitoring (MNM). Methods. From January 2019 to May 2021, 22 patients (17 male and 5 female patients) with transforaminal sacral fractures who were treated with closed reduction and placement of TiRobot-assisted TITS screws under MNM were retrospectively evaluated. The average age of the patients was 43.32 ± 11.40 years (range: 19–63). The patients received MNM, including somatosensory-evoked potentials (SEPs), motor-evoked potentials (MEPs), and electromyographic monitoring (EMG), prior to surgery, during closed reduction and the placement of the guidewire and TITS screw, and at the end of surgery. The operation was adjusted according to the MNM results. Results. Overall, 22 TITS screws were inserted in 22 patients, including 5 TITS screws in the S1 body and 17 TITS screws in the S2 body. The average time needed for screw placement was 27.95 ± 6.84 mins, and the average frequency of X-ray fluoroscopy exposures was 31.00 ± 5.56 for each patient. Anterior ring fixation was performed in 4 patients using an external fixator, in 5 patients using cannulated screws, and in 13 patients using reconstruction plates. The mean follow-up time was 14.46 ± 2.46 months (12–20 months). Tornetta and Matta radiographic outcomes were excellent in 10 patients, good in 9 patients, fair in 2 patients, and poor in 1 patient. The proportion of excellent and good ratings was 86.36%. At the final follow-up, the average Majeed score was 82.18 ± 14.52, with clinical outcomes that were excellent in 9 patients, good in 9 patients, fair in 1 patient, and poor in 3 patients. The proportion of excellent and good ratings was 82.82%. Preoperatively, the amplitude of the SEP on the injured side was lower than that on the contralateral side before reduction in 9 patients (>50%). In this study, no screw was mistakenly inserted into the sacral canal, and no surgical site infection occurred. Conclusion. MNM combined with TiRobot assistance can safely implant TITS screws and can effectively identify the neurological function of patients under anesthesia and reduce iatrogenic nerve injury.

目的：探讨高频超声在肘管综合征诊断中的应用价值。方法：采用 Philips IU22超声诊断仪对56例临床疑似肘管综合征患者的肘部进行高频超声检查，详细观察并总结尺神经声像图特征，明确卡压位置和原因，测量尺神经最厚处的内径，并用包络法从神经外膜的内侧测量肘部尺神经最大横截面积，与健侧进行对比。结果：健侧正常肘部尺神经的声像图纵切面表现为条索状、平行排列的低回声束，其间分隔有线状高回声带；横截面呈类圆形或椭圆形，周围有高回声包绕，似蜂巢状。3例患侧肘部尺神经形态未见异常；53例尺神经形态异常，声像图表现为神经肿胀增粗且粗细不均，横截面积增大，神经束状回声模糊或消失。5例尺神经旁可见囊肿。患侧肘部尺神经厚度及最大横截面积均大于健侧。患侧肘部尺神经最大横截面积随着肘部运动神经传导速度的降低而增大。结论：高频超声可提供尺神经卡压部位的形态学变化，并能发现某些可能导致神经卡压的原因，弥补了单纯依靠患者临床表现和神经电生理检查的不足，可作为诊断肘管综合征的重要补充手段。

BACKGROUND:Somatosensory evoked potential (SSEP) monitoring is performed to examine postoperative clinical findings when a monitoring event was noted intraoperatively and to ascertain the alarm threshold for intraoperative neural damage. METHODS:The tibial SSEP of both lower limbs was recorded intraoperatively in patients with idiopathic scoliosis. Change of SSEP amplitude as opposed to the baseline was categorized into 4 levels: decrease <40%, decrease of 40%-50%, decrease of 50%-60%, and decrease >60%. Postoperative neurologic function of patients was examined and compared with SSEP data. RESULTS:The baseline amplitude before incision was significantly different from the amplitude after spine exposure. An amplitude reduction of >60% during scoliosis correction procedures was observed in 6 legs, and 4 of them had postoperative deterioration in motor status. As the measure of threshold for alarm, an amplitude reduction of >50% compared with baseline resulted in more false-positive outcomes compared with amplitude attenuation of >60%. CONCLUSIONS:Compared with the traditional SSEP baseline before skin incision, the baseline acquired after spine exposure results in more accurate monitoring. A >60% decrease in SSEP amplitude could be a more suitable alarm threshold.

Objective To compare the application value of high frequency ultrasound and neural electrophysiological examination in diagnosis of cubital tunnel syndrome(CTS). Methods High frequency ultrasound and neural electrophysiological examination were performed in 100 patients with unilateral cubital tunnel syndrome (the affected side limb as the CTS group,the contralateral side limb as the control group). The cross-sectional area (CSA) of the elbow ulnar nerve was measured in the two groups by high frequency ultrasound. The motor nerve conduction velocity (MNCV) was measured by neural electrophysiological examination. And pearson correlation between the largest CSA and MNCV was analyzed in CTS group. By taking the surgical results as the gold standard,the accuracy rate in diagnosis of CTS was compared between the two methods. Results The elbow ulnar nerve largest CSA[(0.14±0.05) cm2] in CTS group was higher than that in control group[(0.06±0.01)cm2],there was significant difference(P<0.01).The elbow ulnar nerve MNCV[(28.53±9.52) m/s] in CTS group was lower than that in control group[(56.17±3.18)m/s],there was significant difference(P<0.01). The elbow ulnar nerve largest CSA was negatively correlated with the MNCV (r=-0.80,P<0.01)in CTS group. The accuracy rate of high frequency ultrasound and neural electrophysiological examination in the diagnosis of CTS was 92% and 90%, respectively. Conclusion High frequency ultrasound and neural electrophysiological examination has important value in diagnosis of CTS. Combination of the two methods could provide more reliable evidence for diagnosis and treatment of CTS.

OBJECTIVE:To explore the choice of timing for baseline and alert levels of somatosensory evoked potential (SEP) monitoring during scoliosis surgery. METHODS:From March 2011 to December 2014, a total of 113 patients with kyphoscoliosis deformity were monitored intraoperatively by SEP. There were 52 males and 61 females with a mean age of (20 ± 15) years. All the patients were recorded preoperativeandintraoperative SEPs on double lower limbs. Latency and amplitude of SEPs were recorded after anesthesia and vertebral laminae exposure respectively and compared with each other. Intraoperative SEPs were compared to baseline as SEP after exposure and divided into 4 groups of A (<40%), B (40%-50%), C (50%-60%) and D (>60%) according to the reduced amplitude. Nerve functions were recorded during follow-ups. RESULTS:Significant statistical difference existed between SEPs post-anesthesia and SEPs after vertebral laminae exposure (P < 0.01). Compared with SEP post-anesthesia, the latency of SEP after exposure was prolonged with (3.28 ± 1.72) ms (left lower limb) and (3.30 ± 2.09) ms (right lower limb) and amplitude decreased with 0.17(0.39) µV (left lower limb) and 0.19(0.40) µV (right lower limb). There was a positive relationship of impaired nerve function between groups C and D (P < 0.05). CONCLUSION:Adopting SEP waveform after exposure as a baseline can improve the accuracy of SEP monitoring during scoliosis surgery. Intraoperative alarm with a reduced amplitude over 50% as the standard may be too sensitive. Alert with a reduced amplitude of over 60% reduces the false positive rate of alarm.