Quantitative measurement of finger usage in stroke hemiplegia using ring-shaped wearable devices.

BACKGROUND: In post-stroke rehabilitation, positive use of affected limbs in daily life is important to improve affected upper-limb function. Several studies have quantitatively evaluated the amount of upper-limb activity, but few have measured finger usage. In this study, we used a ring-shaped wearable device to measure upper-limb and finger usage simultaneously in hospitalized patients with hemiplegic stroke and investigated the association between finger usage and general clinical evaluation. METHODS: Twenty patients with hemiplegic stroke in an inpatient hospital participated in this study. All patients wore a ring-shaped wearable device on both hands for 9 h on the day of the intervention, and their finger and upper-limb usage were recorded. For the rehabilitation outcome assessments, the Fugl-Meyer Assessment of the Upper Extremity (FMA-UE), Simple Test for Evaluating Hand Function (STEF), Action Research Arm Test (ARAT), Motor Activity Log-14 (MAL), and Functional Independence Measure Motor (FIM-m) were performed and evaluated on the same day as the intervention. RESULTS: Finger usage of the affected hand was moderately correlated with STEF ([Formula: see text], [Formula: see text]) and STEF ratio ([Formula: see text], [Formula: see text]). The finger-usage ratio was moderately correlated with FMA-UE ([Formula: see text], [Formula: see text]) and ARAT ([Formula: see text], [Formula: see text]), and strongly correlated with STEF ([Formula: see text], [Formula: see text]) and STEF ratio ([Formula: see text], [Formula: see text]). The upper-limb usage of the affected side was moderately correlated with FMA-UE ([Formula: see text], [Formula: see text]), STEF ([Formula: see text], [Formula: see text]) and STEF ratio ([Formula: see text], [Formula: see text]), and strongly correlated with ARAT ([Formula: see text], [Formula: see text]). The upper-limb usage ratio was moderately correlated with ARAT ([Formula: see text], [Formula: see text]) and STEF ([Formula: see text], [Formula: see text]), and strongly correlated with the STEF ratio ([Formula: see text], [Formula: see text]). By contrast, there was no correlation between MAL and any of the measurements. CONCLUSIONS: This measurement technique provided useful information that was not biased by the subjectivity of the patients and therapists.

Understanding the effect of non-surgical factors in a transcranial motor-evoked potential alert: A retrospective cohort study.

BACKGROUND: Intraoperative neuromonitoring (IONM) is important for detecting neurological dysfunction, allowing for intervention and reversal of neurological deficits before they become permanent. Of the several IONM modalities, transcranial electrical stimulation of motor-evoked potential (TES-MEP) can help monitor the activity in the pyramidal tract. Surgery- and non-surgery-related factors could result in a TES-MEP alert during surgery. Once the alert occurs, the surgeon should immediately intervene to prevent a neurological complication. However, TES-MEP monitoring does not provide sufficient data to identify the non-surgery-related factors. Therefore, this study aimed to identify and describe these factors among TES-MEP alert cases. METHODS: In this multicenter study, data from 1934 patients who underwent various spinal surgeries for spinal deformities, spinal cord tumors, and ossification of the posterior longitudinal ligament of the spine from 2017 to 2019 were collected. A 70% amplitude reduction was set as the TES-MEP alarm threshold. All surgeries with alerts were categorized into true-positive (TP) and false-positive (FP) cases according to the assessment of immediate postoperative neurological deficits. RESULTS: In total, TES-MEP alerts were observed in 251 cases during surgery: 62 TP and 189 FP IONM cases. Overall, 158 cases were related to non-surgery-related factors. We observed 22 (35.5%) TP cases and 136 (72%) FP cases, which indicated cases associated with non-surgery-related factors. A significant difference was observed between the two groups regarding factors associated with TES-MEP alerts (p < 0.01). The ratio of TP and FP cases (related to non-surgery-related factors) associated with TES-MEP alerts was 13.9% (22/158 cases) and 86.1% (136/158 cases), respectively. CONCLUSIONS: Non-surgery-related factors are proportionally higher in FP than in TP cases. Although the surgeon should examine surgical procedures immediately after a TES-MEP alert, surgical intervention may not always be the best approach according to the results of this study.

Red/Far Red Light Controls Arbuscular Mycorrhizal Colonization via Jasmonic Acid and Strigolactone Signaling.

Establishment of a nitrogen-fixing symbiosis between legumes and rhizobia not only requires sufficient photosynthate, but also the sensing of the ratio of red to far red (R/FR) light. Here, we show that R/FR light sensing also positively influences the arbuscular mycorrhizal (AM) symbiosis of a legume and a non-legume through jasmonic acid (JA) and strigolactone (SL) signaling. The level of AM colonization in high R/FR light-grown tomato and Lotus japonicus significantly increased compared with that determined for low R/FR light-grown plants. Transcripts for JA-related genes were also elevated under high R/FR conditions. The root exudates derived from high R/FR light-grown plants contained more (+)-5-deoxystrigol, an AM-fungal hyphal branching inducer, than those from low R/FR light-grown plants. In summary, high R/FR light changes not only the levels of JA and SL synthesis, but also the composition of plant root exudates released into the rhizosphere, in this way augmenting the AM symbiosis.

20/(fasting C-peptide × fasting plasma glucose) is a simple and effective index of insulin resistance in patients with type 2 diabetes mellitus: a preliminary report.

BACKGROUND: We developed a simple and new insulin resistance index derived from a glucose clamp and a meal tolerance test (MTT) in Japanese patients with type 2 diabetes mellitus. METHODS: Fifteen patients [mean age: 53 years, fasting plasma glucose (FPG) 7.7 mmol/L, HbA1c 7.1% (54 mmol/mol), body mass index 26.8 kg/m(2)] underwent a MTT and a glucose clamp. Participants were given a test meal (450 kcal). Plasma glucose and insulin were measured at 0 (fasting), 30, 60, 120, and 180 min. Serum C-peptide immunoreactivity (CPR) was measured at 0 (fasting; F-CPR) and 120 min. Homeostasis model assessment of insulin resistance (HOMA-IR) and insulin sensitivity indices (ISI) were calculated from the MTT results. The glucose infusion rate (GIR) was measured during hyperinsulinemic-euglycemic glucose clamps. RESULTS: The mean GIR in all patients was 5.8 mg·kg(-1)·min(-1). The index 20/(F-CPR × FPG) was correlated strongly with GIR (r = 0.83, P < 0.0005). HOMA-IR (r = -0.74, P < 0.005) and ISI (r = 0.66, P < 0.01) were also correlated with GIR. In 10 patients with mild insulin resistance (GIR 5.0-10.0 mg·kg(-1)·min(-1)), 20/(F-CPR × FPG) was very strongly correlated with GIR (r = 0.90, P < 0.0005), but not with HOMA-IR and ISI (r = -0.49, P = 0.15; r = 0.20, P = 0.56, respectively). In patients with mild insulin resistance, plasma adiponectin (r = 0.65, P < 0.05), but not BMI or waist circumstance, was correlated with GIR. CONCLUSIONS: 20/(F-CPR × FPG) is a simple and effective index of insulin resistance, and performs better than HOMA-IR and ISI in Japanese patients with type 2 diabetes mellitus. Our results suggest that 20/(F-CPR × FPG) is a more effective index than HOMA-IR in Japanese patients with mild insulin resistance.

Usefulness of multi-channels in intraoperative spinal cord monitoring: multi-center study by the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research.

OBJECT: The purpose of this study is to analyze the data in terms of the number of channels employed to examine the usefulness of multi-channels in intraoperative spinal cord monitoring. METHODS: The prerequisites for inclusion in the baseline data were as follows: (1) cases in which only CMAP monitoring was conducted; (2) cases in which monitoring was conducted under the same stimulation condition and the recording condition. Cases where inhalation anesthesia was used or muscle relaxants were used as maintenance anesthesia was excluded from the baseline data. Of the 6,887 cases, 884 cases met the criteria. The items examined for each of the different numbers of channels were the sensitivity and specificity, the false positive rate, the false negative rate, and the coverage rate of postoperative motor deficit muscles. RESULT: To examine these two items in terms of the number of channels, the 4-channel group had lower sensitivity and specificity scores compared with the 8- and 16-channel groups (4 channels 73/93 %, 8 channels 100/97 %, 16 channels 100/95 %). Only four channels were derived for these cases and the coverage of postoperative motor deficit muscles was 38 % with only 30 out of the 80 postoperative motor deficit muscles in total being monitored. In the 8-channel group, it was 60 % with 12 of the 20 postoperative motor deficit muscles being monitored. The 16-channel group had 100 % coverage rate of postoperative motor deficit muscles. CONCLUSION: We suggest that multi-channel monitoring of at least eight channels is desirable for intraoperative spinal cord monitoring.

Return-to-Sport Rate, Type of Sport, Frequency of Participation, and Patient Satisfaction After Elective Spinal Surgery in the Elderly Population.

Background: The number of elderly sports participants is increasing, and the possibility of return to sport (RTS) has become an important part of surgical decision making in this population. Purpose: To investigate RTS after elective spinal surgery in elderly patients. Study Design: Case series; Level of evidence, 4. Methods: We enrolled patients aged ≥65 years with a history of preoperative or preinjury sports participation who underwent elective spinal surgery at a single institution between 2019 and 2021. At minimum 12-month follow-up, a questionnaire was administered to each participant to assess postoperative RTS, timing of return, frequency and type of pre- and postoperative activities, and satisfaction (scored 1-10). Descriptive statistical analyses were performed, and regression models were developed to examine the influence of age and sex, as well as surgical site, on RTS. Results: A total of 53 patients (mean ± SD age, 73.8 ± 5.2 years; 24 women) were included, and 23 (43.4%) returned to sports at a median 6 months (interquartile range, IQR, 2-6 months). The RTS rate by surgical site was 17 of 34 (50%) for the lumbar spine and 6 of 17 (35.3%) for the cervical spine. There were no statistically significant differences in RTS rate by surgical site, age, or sex. Overall, 6 of 17 patients returned to golf, 4 of 6 to dance, 2 of 5 to swimming, and 1 of 5 to tennis. Of patients who returned, 34.8% participated in sports 5 times per week and 26.1% participated 3 times per week. The median satisfaction score after RTS was 8 (IQR, 6-9). Conclusion: RTS after spinal surgery was achieved in 43% patients at 1-year minimum follow-up, with high satisfaction scores. More than half of the returning patients participated in sports activities ≥3 times per week.

Current Trends in Intraoperative Spinal Cord Monitoring: A Survey Analysis among Japanese Expert Spine Surgeons.

Introduction: Although intraoperative spinal neuromonitoring (IONM) is recommended for spine surgeries, there are no guidelines regarding its use in Japan, and its usage is mainly based on the surgeon's preferences. Therefore, this study aimed to provide an overview of the current trends in IONM usage in Japan. Methods: In this web-based survey, expert spine surgeons belonging to the Japanese Society for Spine Surgery and Related Research were asked to respond to a questionnaire regarding IONM management. The questionnaire covered various aspects of IONM usage, including the preferred modality, operation of IONM, details regarding muscle-evoked potential after electrical stimulation of the brain (Br(E)-MsEP), and need for consistent use of IONM in major spine surgeries. Results: Responses were received from 134 of 186 expert spine surgeons (response rate, 72%). Of these, 124 respondents used IONM routinely. Medical staff rarely performed IONM without a medical doctor. Br(E)-MsEP was predominantly used for IONM. One-third of the respondents reported complications, such as bite injuries caused by Br(E)-MsEP. Interestingly, two-thirds of the respondents did not plan responses to alarm points. Intramedullary spinal cord tumor, scoliosis (idiopathic, congenital, or neuromuscular in pediatric), and thoracic ossification of the posterior longitudinal ligament were representative diseases that require IONM. Conclusions: IONM has become an essential tool in Japan, and Br(E)-MsEP is a predominant modality for IONM at present. Although we investigated spine surgeries for which consistent use of IONM is supported, a cost-benefit analysis may be required.

Efficacy of Transcranial Motor Evoked Potential Monitoring During Intra- and Extramedullary Spinal Cord Tumor Surgery: A Prospective Multicenter Study of the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research.

STUDY DESIGN: Multicenter prospective study. OBJECTIVES: Although intramedullary spinal cord tumor (IMSCT) and extramedullary SCT (EMSCT) surgeries carry high risk of intraoperative motor deficits (MDs), the benefits of transcranial motor evoked potential (TcMEP) monitoring are well-accepted; however, comparisons have not yet been conducted. This study aimed to clarify the efficacy of TcMEP monitoring during IMSCT and EMSCT resection surgeries. METHODS: We prospectively reviewed TcMEP monitoring data of 81 consecutive IMSCT and 347 EMSCT patients. We compared the efficacy of interventions based on TcMEP alerts in the IMSCT and EMSCT groups. We defined our alert point as a TcMEP amplitude reduction of ≥70% from baseline. RESULTS: In the IMSCT group, TcMEP monitoring revealed 20 true-positive (25%), 8 rescue (10%; rescue rate 29%), 10 false-positive, a false-negative, and 41 true-negative patients, resulting in a sensitivity of 95% and a specificity of 80%. In the EMSCT group, TcMEP monitoring revealed 20 true-positive (6%), 24 rescue (7%; rescue rate 55%), 29 false-positive, 2 false-negative, and 263 true-negative patients, resulting in a sensitivity of 91% and specificity of 90%. The most common TcMEP alert timing was during tumor resection (96% vs. 91%), and suspension surgeries with or without intravenous steroid administration were performed as intervention techniques. CONCLUSIONS: Postoperative MD rates in IMSCT and EMSCT surgeries using TcMEP monitoring were 25% and 6%, and rescue rates were 29% and 55%. We believe that the usage of TcMEP monitoring and appropriate intervention techniques during SCT surgeries might have predicted and prevented the occurrence of intraoperative MDs.

Role of Transcranial Motor Evoked Potential Monitoring During Traumatic Spinal Injury Surgery: A Prospective Multicenter Study of the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research.

STUDY DESIGN: A prospective multicenter observational cohort study. OBJECTIVE: This study aimed to investigate the role of transcranial motor evoked potential (TcMEP) monitoring during traumatic spinal injury surgery, the timing of TcMEP alerts, and intervention strategies to avoid intraoperative neurological complications. SUMMARY OF BACKGROUND DATA: Intraoperative neuromonitoring, including TcMEP monitoring, is commonly used in high-risk spinal surgery to predict intraoperative spinal cord injury; however, little information is available on its use in traumatic spinal injury surgery. METHODS: The TcMEP monitoring data of 350 consecutive patients who underwent traumatic spinal injury surgery (mean age, 69.3 y) between 2017 and 2021 were prospectively reviewed. In this study, a TcMEP amplitude reduction ≥70% was established as a TcMEP alert. A rescue case was defined as a case with the recovery of TcMEP amplitudes after certain procedures and without postoperative neurological complications. RESULTS: Among the 350 patients who underwent traumatic spinal injury surgery (TcMEP derivation rate 94%), TcMEP monitoring revealed seven true-positive (TP) (2.0%), three rescues (0.9%; rescue rate 30%), 31 false-positive, one false-negative, and 287 true-negative cases, resulting in 88% sensitivity, 90% specificity, 18% positive predictive value, and 99% negative predictive value. The TP rate in patients with preoperative motor deficits was 2.9%, which was higher than that in patients without preoperative motor deficits (1.1%). The most common timing of TcMEP alerts was during decompression (40%). During decompression, suspension of surgery with intravenous steroid injection was ineffective (rescue rate, 0%), and additional decompression was effective. CONCLUSION: Given the low prevalence of neurological complications (2.3%) and the low positive predictive value (18.4%), single usage of TcMEP monitoring during traumatic spinal injury surgery is not recommended. Further efforts should be made to reduce FP alert rates through better interpretation of multimodal Intraoperative neuromonitorings and the incorporation of anesthesiology to improve the positive predictive value. LEVEL OF EVIDENCE: 3.

Impact of Preoperative Motor Status for the Positive Predictive Value of Transcranial Motor-Evoked Potentials Alerts in Thoracic Spine Surgery: A Prospective Multicenter Study by the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research.

STUDY DESIGN: Prospective multicenter study. OBJECTIVE: To investigate the validity of transcranial motor-evoked potentials (Tc-MEP) in thoracic spine surgery and evaluate the impact of specific factors associated with positive predictive value (PPV). METHODS: One thousand hundred and fifty-six cases of thoracic spine surgeries were examined by comparing patient backgrounds, disease type, preoperative motor status, and Tc-MEP alert timing. Tc-MEP alerts were defined as an amplitude decrease of more than 70% from the baseline waveform. Factors were compared according to preoperative motor status and the result of Tc-MEP alerts. Factors that showed significant differences were identified by univariate and multivariate analysis. RESULTS: Overall sensitivity was 91.9% and specificity was 88.4%. The PPV was significantly higher in the preoperative motor deficits group than in the preoperative no-motor deficits group for both high-risk (60.3% vs 38.3%) and non-high-risk surgery groups (35.1% vs 12.8%). In multivariate logistic analysis, the significant factors associated with true positive were surgical maneuvers related to ossification of the posterior longitudinal ligament (odds ratio = 11.88; 95% CI: 3.17-44.55), resection of intradural intramedullary spinal cord tumor (odds ratio = 8.83; 95% CI: 2.89-27), preoperative motor deficit (odds ratio = 3.46; 95% CI: 1.64-7.3) and resection of intradural extramedullary spinal cord tumor (odds ratio = 3.0; 95% CI: 1.16-7.8). The significant factor associated with false positive was non-attributable alerts (odds ratio = .28; 95% CI: .09-.85). CONCLUSION: Surgeons are strongly encouraged to use Tc-MEP in patients with preoperative motor deficits, regardless of whether they are undergoing high-risk spine surgery or not. Knowledge of PPV characteristics will greatly assist in effective Tc-MEP enforcement and minimize neurological complications with appropriate interventions.

Efficacy of D-Wave Monitoring Combined With the Transcranial Motor-Evoked Potentials in High-Risk Spinal Surgery: A Retrospective Multicenter Study of the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research.

STUDY DESIGN: Retrospective multicenter cohort study. OBJECTIVES: We aimed to clarify the efficacy of multimodal intraoperative neuromonitoring (IONM), especially in transcranial electrical stimulation of motor-evoked potentials (TES-MEPs) with spinal cord-evoked potentials after transcranial stimulation of the brain (D-wave) in the detection of reversible spinal cord injury in high-risk spinal surgery. METHODS: We reviewed 1310 patients who underwent TES-MEPs during spinal surgery at 14 spine centers. We compared the monitoring results of TES-MEPs with D-wave vs TES-MEPs without D-wave in high-risk spinal surgery. RESULTS: There were 40 cases that used TES-MEPs with D-wave and 1270 cases that used TES-MEPs without D-wave. Before patients were matched, there were significant differences between groups in terms of sex and spinal disease category. Although there was no significant difference in the rescue rate between TES-MEPs with D-wave (2.0%) and TES-MEPs (2.5%), the false-positivity rate was significantly lower (0%) in the TES-MEPs-with-D-wave group. Using a one-to-one propensity score-matched analysis, 40 pairs of patients from the two groups were selected. Baseline characteristics did not significantly differ between the matched groups. In the score-matched analysis, one case (2.5%) in both groups was a case of rescue (P = 1), five (12.5%) cases in the TES-MEPs group were false positives, and there were no false positives in the TES-MEPs-with-D-wave group (P = .02). CONCLUSIONS: TES-MEPs with D-wave in high-risk spine surgeries did not affect rescue case rates. However, it helped reduce the false-positivity rate.

Transcranial Motor-evoked Potentials for Intraoperative Nerve Root Monitoring During Adult Spinal Deformity Surgery: A Prospective Multicenter Study.

STUDY DESIGN: A prospective, multicenter study. OBJECTIVE: This study clarified the uses and limitations of transcranial motor-evoked potentials (Tc-MEPs) for nerve root monitoring during adult spinal deformity (ASD) surgeries. SUMMARY OF BACKGROUND DATA: Whether Tc-MEPs can detect nerve root injuries (NRIs) in ASD surgeries remains controversial. MATERIALS AND METHODS: We prospectively analyzed neuromonitoring data from 14 institutions between 2017 and 2020. The subjects were ASD patients surgically treated with posterior corrective fusion using multichannel Tc-MEPs. An alert was defined as a decrease of ≥70% in the Tc-MEP's waveform amplitude from baseline, and NRI was considered as meeting the focal Tc-MEP alerts shortly following surgical procedures with postoperative nerve root symptoms in the selected muscles. RESULTS: A total of 311 patients with ASD (262 women and 49 men) and a mean age of 65.5 years were analyzed. Tc-MEP results revealed 47 cases (15.1%) of alerts, including 25 alerts after 10 deformity corrections, six three-column osteotomies, four interbody fusions, three pedicle screw placements or two decompressions, and 22 alerts regardless of surgical maneuvers. Postoperatively, 14 patients (4.5%) had neurological deterioration considered to be all NRI, 11 true positives, and three false negatives (FN). Two FN did not reach a 70% loss of baseline (46% and 65% loss of baseline) and one was not monitored at target muscles. Multivariate logistic regression analysis revealed that risk factors of NRI were preexisting motor weakness ( P <0.001, odds ratio=10.41) and three-column osteotomies ( P =0.008, odds ratio=7.397). CONCLUSIONS: Nerve root injuries in our ASD cohort were partially predictable using multichannel Tc-MEPs with a 70% decrease in amplitude as an alarm threshold. We propose that future research should evaluate the efficacy of an idealized warning threshold (e.g., 50%) and a more detailed evoked muscle selection, in reducing false negatives.

The Utility of Transcranial Stimulated Motor-Evoked Potential Alerts in Cervical Spine Surgery Varies Based on Preoperative Motor Status.

STUDY DESIGN: A prospective multicenter observational study. OBJECTIVE: The aim was to investigate the validity of transcranial motor-evoked potentials (Tc-MEP) in cervical spine surgery and identify factors associated with positive predictive value when Tc-MEP alerts are occurred. SUMMARY OF BACKGROUND DATA: The sensitivity and specificity of Tc-MEP for detecting motor paralysis are high; however, false-positives sometimes occur. MATERIALS AND METHODS: The authors examined Tc-MEP in 2476 cases of cervical spine surgeries and compared patient backgrounds, type of spinal disorders, preoperative motor status, surgical factors, and the types of Tc-MEP alerts. Tc-MEP alerts were defined as an amplitude reduction of more than 70% from the control waveform. Tc-MEP results were classified into two groups: false-positive and true-positive, and items that showed significant differences were extracted by univariate analysis and detected by multivariate analysis. RESULTS: Overall sensitivity was 66% (segmental paralysis: 33% and lower limb paralysis: 95.8%) and specificity was 91.5%. Tc-MEP outcomes were 33 true-positives and 233 false-positives. Positive predictive value of general spine surgery was significantly higher in cases with a severe motor status than in a nonsevere motor status (19.5% vs . 6.7%, P =0.02), but not different in high-risk spine surgery (20.8% vs . 19.4%). However, rescue rates did not significantly differ regardless of motor status (48% vs . 50%). In a multivariate logistic analysis, a preoperative severe motor status [ P =0.041, odds ratio (OR): 2.46, 95% confidence interval (95% CI): 1.03-5.86] and Tc-MEP alerts during intradural tumor resection ( P <0.001, OR: 7.44, 95% CI: 2.64-20.96) associated with true-positives, while Tc-MEP alerts that could not be identified with surgical maneuvers ( P =0.011, OR: 0.23, 95% CI: 0.073-0.71) were associated with false-positives. CONCLUSION: The utility of Tc-MEP in patients with a preoperative severe motor status was enhanced, even in those without high-risk spine surgery. Regardless of the motor status, appropriate interventions following Tc-MEP alerts may prevent postoperative paralysis.

Comparison of intraoperative neuromonitoring accuracies and procedures associated with alarms in anterior versus posterior fusion for cervical spinal disorders: A prospective multi-institutional cohort study.

A prospective multicenter cohort study. To clarify the differences in the accuracy of transcranial motor-evoked potentials (TcE-MEPs) and procedures associated with the alarms between cervical anterior spinal fusion (ASF) and posterior spinal fusion (PSF). Neurological complications after TcE-MEP alarms have been prevented by appropriate interventions for cervical degenerative disorders. The differences in the accuracy of TcE-MEPs and the timing of alarms between cervical ASF and PSF noted in the existing literature remain unclear. Patients (n = 415) who underwent cervical ASF (n = 171) or PSF (n = 244) at multiple institutions for cervical spondylotic myelopathy, ossification of the posterior longitudinal ligament, spinal injury, and others were analyzed. Neurological complications, TcE-MEP alarms defined as a decreased amplitude of ≤70% compared to the control waveform, interventions after alarms, and TcE-MEP results were compared between the 2 surgeries. The incidence of neurological complications was 1.2% in the ASF group and 2.0% in the PSF group, with no significant intergroup differences (P-value was .493). Sensitivity, specificity, negative predictive value, and rate of rescue were 50.0%, 95.2%, 99.4%, and 1.8%, respectively, in the ASF group, and 80.0%, 90.9%, 99.5%, and 2.9%, respectively, in the PSF group. The accuracy of TcE-MEPs was not significantly different between the 2 groups (P-value was .427 in sensitivity, .109 in specificity, and .674 in negative predictive value). The procedures associated with the alarms were decompression in 3 cases and distraction in 1 patient in the ASF group. The PSF group showed Tc-MEPs decreased during decompression, mounting rods, turning positions, and others. Most alarms went off during decompression in ASF, whereas various stages of the surgical procedures were associated with the alarms in PSF. There were no significant differences in the accuracy of TcE-MEPs between the 2 surgeries.

Characteristics of Tc-MEP Waveforms for Different Locations of Intradural Extramedullary Tumors: A Prospective Multicenter Study of the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research.

STUDY DESIGN: Prospective multicenter study. OBJECTIVE: To examine transcranial motor-evoked potential (Tc-MEP) waveforms in intraoperative neurophysiological monitoring in surgery for intradural extramedullary (IDEM) tumors, focused on the characteristics for cervical, thoracic, and conus lesions. SUMMARY OF BACKGROUND DATA: IDEM tumors are normally curable after resection, but neurological deterioration may occur after surgery. Intraoperative neurophysiological monitoring using Tc-MEPs during surgery is important for timely detection of possible neurological injury. METHODS: The subjects were 233 patients with IDEM tumors treated surgically with Tc-MEP monitoring at 9 centers. The alarm threshold was ≥70% waveform deterioration from baseline. A case with a Tc-MEP alert that normalized and had no new motor deficits postoperatively was defined as a rescue case. A deterioration of manual muscle test score ≥1 compared to the preoperative value was defined as postoperative worsening of motor status. RESULTS: The 233 patients (92 males, 39%) had a mean age of 58.1 ±â€Š18.1 years, and 185 (79%), 46 (20%), and 2 (1%) had schwannoma, meningioma, and neurofibroma. These lesions had cervical (C1-7), thoracic (Th1-10), and conus (Th11-L2) locations in 82 (35%), 96 (41%), and 55 (24%) cases. There were no significant differences in preoperative motor deficit among the lesion levels. Thoracic lesions had a significantly higher rate of poor baseline waveform derivation (0% cervical, 6% thoracic, 0% conus, P < 0.05) and significantly more frequent intraoperative alarms (20%, 31%, 15%, P < 0.05). Use of Tc-MEPs for predicting neurological deficits after IDEM surgery had sensitivity of 87% and specificity of 89%; however, the positive predictive value was low. CONCLUSION: Poor derivation of waveforms, appearance of alarms, and worse final waveforms were all significantly more frequent for thoracic lesions. Thus, amplification of the waveform amplitude, using multimodal monitoring, and more appropriate interventions after an alarm may be particularly important in surgery for thoracic IDEM tumors.Level of Evidence: 3.

Efficacy of Intraoperative Neuromonitoring Using Transcranial Motor-Evoked Potentials for Degenerative Cervical Myelopathy: A Prospective Multicenter Study by the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research.

STUDY DESIGN: A prospective multicenter observational study. OBJECTIVE: To elucidate the efficacy of transcranial motor-evoked potentials (Tc(E)-MEPs) in degenerative cervical myelopathy (DCM) surgery by comparing cervical spondylotic myelopathy (CSM) to cervical ossification of the posterior longitudinal ligament (OPLL) and investigate the timing of Tc(E)-MEPs alerts and types of interventions affecting surgical outcomes. SUMMARY OF BACKGROUND DATA: Although CSM and OPLL are the most commonly encountered diseases of DCM, the benefits of Tc(E)-MEPs for DCM remain unclear and comparisons of these two diseases have not yet been conducted. METHODS: We examined the results of Tc(E)-MEPs from 1176 DCM cases (840 CSM /336 OPLL) and compared patients background by disease, preoperative motor deficits, and the type of surgical procedure. We also assessed the efficacy of interventions based on Tc(E)-MEPs alerts. Tc(E)-MEPs alerts were defined as an amplitude reduction of more than 70% below the control waveform. Rescue cases were defined as those in which waveform recovery was achieved after interventions in response to alerts and no postoperative paralysis. RESULTS: Overall sensitivity was 57.1%, and sensitivity was higher with OPLL (71.4%) than with CSM (42.9%). The sensitivity of acute onset segmental palsy including C5 palsy was 40% (OPLL/CSM: 66.7%/0%) whereas that of lower limb palsy was 100%. The most common timing of Tc(E)-MEPs alerts was during decompression (63.16%), followed by screw insertion (15.79%). The overall rescue rate was 57.9% (OPLL/CSM: 58.3%/57.1%). CONCLUSION: Since Tc(E)-MEPs are excellent for detecting long tract injuries, surgeons need to consider appropriate interventions in response to alerts. The detection of acute onset segmental palsy by Tc(E)-MEPs was partially possible with OPLL, but may still be difficult with CSM. The rescue rate was higher than 50% and appropriate interventions may have prevented postoperative neurological complications.Level of Evidence: 3.

Transcranial Motor-evoked Potential Alert After Supine-to-Prone Position Change During Thoracic Ossification in Posterior Longitudinal Ligament Surgery: A Prospective Multicenter Study of the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research.

STUDY DESIGN: A prospective, multicenter study. OBJECTIVE: To evaluate the usefulness of transcranial motor-evoked potentials (Tc-MEPs) during supine-to-prone position change for thoracic ossification of the posterior longitudinal ligament (T-OPLL). SUMMARY OF BACKGROUND DATA: Supine-to-prone position change might be a risk of spinal cord injury in posterior decompression and fusion surgeries for T-OPLL. METHODS: The subjects were 145 patients with T-OPLL surgically treated with posterior decompression and fusion using Tc-MEPs in 14 institutes. Tc-MEPs were monitored before surgery from supine-to-prone position and intraoperatively in seven institutes and only intraoperatively in the other seven institutes because of disapproval of the anesthesia department. In cases of Tc-MEP alert after position change, we adjusted the cervicothoracic posture. When the MEP did not recover, we reverted the position to supine and monitored the Tc-MEPs in supine position. RESULTS: There were 83 and 62 patients with/without Tc-MEP before position change to prone (group A and B). The true-positive rate was lower in group A than group B, but without statistical significance (8.4% vs. 16.1%, P = 0.12). In group A, five patients who had Tc-MEP alert during supine-to-prone position change were all female and had larger body mass index values and upper thoracic lesions. Among the patients, three underwent surgeries after cervicothoracic alignment adjustment, and two had postponed operations to 1 week later with halo-vest fixation because of repeated Tc-MEP alerts during position change to prone. The Tc-MEP alert at exposure was statistically more frequent in group B than in group A ( P = 0.033). CONCLUSION: Tc-MEP alert during position change is an important sign of spinal cord injury due to alignment change at the upper thoracic spine. Tc-MEP monitoring before supine-to-prone position change was necessary to prevent spinal cord injury in surgeries for T-OPLL.

Arthroscopic treatment for Morel-Lavallée lesion of the thigh: A case report and literature review.

INTRODUCTION: Morel-Lavallée lesion (MLL) is a posttraumatic closed degloving soft tissue injury, in which the subcutaneous tissues are separated from the underlying fascia. Surgical treatment is recommended if conservative management fails. The conventional surgical treatment for the lesion is surgical drainage and debridement. PRESENTATION OF CASE: A 51-year-old male patient presented with swelling of the right thigh incurred during a traffic accident. The lesion was diagnosed with MLL. The MLL was successfully treated with a minimally invasive arthroscopic treatment after failure of conservative treatment. The arthroscopic treatment was chosen because of the patient's comorbidity that posed a risk of surgical wound complications. In addition, negative pressure wound therapy (NPWT) was performed postoperatively to ensure healing and to prevent recurrence of the lesion. The patient was successfully treated and the healing of the lesion was also confirmed with MRI. DISCUSSION: In a patient with a risk of wound complications due to a comorbidity, this minimally invasive arthroscopic treatment is useful. In addition, NPWT was used to ensure healing and to prevent recurrence. Although the use of NPWT combined with endoscopic treatment has not been reported, additional NPWT reported in this case may be helpful to ensure healing. CONCLUSION: In case of MLL with a risk of surgical complications, the arthroscopic treatment is a reasonable method and achieves the goal of an open surgical debridement without increased morbidity.

Effects of Preoperative Motor Status on Intraoperative Motor-evoked Potential Monitoring for High-risk Spinal Surgery: A Prospective Multicenter Study.

STUDY DESIGN: Prospective multicenter observational study. OBJECTIVE: To evaluate transcranial motor-evoked potentials (Tc-MEPs) baseline characteristics of lower limb muscles and to determine the accuracy of Tc-MEPs monitoring based on preoperative motor status in surgery for high-risk spinal disease. SUMMARY OF BACKGROUND DATA: Neurological complications are potentially serious side effects in surgery for high-risk spine disease. Intraoperative spinal neuromonitoring (IONM) using Tc-MEPs waveforms can be used to identify neurologic deterioration, but cases with preoperative motor deficit tend to have poor waveform derivation. METHODS: IONM was performed using Tc-MEPs for 949 patients in high-risk spinal surgery. A total of 4454 muscles in the lower extremities were chosen for monitoring. The baseline Tc-MEPs was recorded immediately after exposure of the spine. The derivation rate was defined as muscles detected/muscles prepared for monitoring. A preoperative neurological grade was assigned using the manual muscle test (MMT) score. RESULTS: The 949 patients (mean age 52.5 ±â€Š23.3 yrs, 409 males [43%]) had cervical, thoracic, thoracolumbar, and lumbar lesions at rates of 32%, 40%, 26%, and 13%, respectively. Preoperative severe motor deficit (MMT ≤3) was present in 105 patients (11%), and thoracic ossification of the posterior longitudinal ligament (OPLL) was the most common disease in these patients. There were 32 patients (3%) with no detectable waveform in any muscles, and these cases had mostly thoracic lesions. Baseline Tc-MEPs responses were obtained from 3653/4454 muscles (82%). Specificity was significantly lower in the severe motor deficit group. Distal muscles had a higher waveform derivation rate, and the abductor hallucis (AH) muscle had the highest derivation rate, including in cases with preoperative severe motor deficit. CONCLUSION: In high-risk spinal surgery, Tc-MEPs collected with multi-channel monitoring had significantly lower specificity in cases with preoperative severe motor deficit. Distal muscles had a higher waveform derivation rate and the AH muscle had the highest rate, regardless of the severity of motor deficit preoperatively.Level of Evidence: 3.

Efficacy of Intraoperative Intervention Following Transcranial Motor-evoked Potentials Alert During Posterior Decompression and Fusion Surgery for Thoracic Ossification of the Posterior Longitudinal Ligament: A Prospective Multicenter Study of the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research.

STUDY DESIGN: Prospective, multicenter, observational study. OBJECTIVE: The aim of this study was to investigate the efficacy of intervention after an alert in intraoperative neurophysiological monitoring (IONM) using transcranial motor-evoked potentials (Tc-MEPs) during surgery for thoracic ossification of the posterior longitudinal ligament (T-OPLL). SUMMARY OF BACKGROUND DATA: T-OPLL is commonly treated with posterior decompression and fusion with instrumentation. IONM using Tc-MEPs during surgery reduces the risk of neurological complications. METHODS: The subjects were 79 patients with a Tc-MEP alert during posterior decompression and fusion surgery for T-OPLL. Preoperative muscle strength (manual muscle testing [MMT]), waveform derivation rate at the start of surgery (baseline), intraoperative waveform changes; and postoperative motor paralysis were examined. A reduction in MMT score of ≥1 on the day after surgery was classified as worsened postoperative motor deficit. An alert was defined as a decrease in Tc-MEP waveform amplitude of ≥70% from baseline. Alerts were recorded at key times during surgery. RESULTS: The patients (35 males, 44 females; age 54.6 years) had OPLL at T1-4 (n = 27, 34%), T5-8 (n = 50, 63%), and T9-12 (n = 16, 20%). The preoperative status included sensory deficit (n = 67, 85%), motor deficit (MMT ≤4) (n = 59, 75%), and nonambulatory (n = 26, 33%). At baseline, 76 cases (96%) had a detectable Tc-MEP waveform for at least one muscle, and the abductor hallucis had the highest rate of baseline waveform detection (n = 66, 84%). Tc-MEP alerts occurred during decompression (n = 47, 60%), exposure (n = 13, 16%), rodding (n = 5, 6%), pedicle screw insertion (n = 4, 5%), posture change (n = 4, 5%), dekyphosis (n = 2, 3%), and other procedures (n = 4, 5%). After intraoperative intervention, the rescue rate (no postoperative neurological deficit) was 57% (45/79), and rescue cases had a significantly better preoperative ambulatory status and a significantly higher baseline waveform derivation rate. CONCLUSION: These results show the efficacy of intraoperative intervention following a Tc-MEP alert for prevention of neurological deficit postoperatively.Level of Evidence: 2.