Timing-dependent synergies between motor cortex and posterior spinal stimulation in humans.

Volitional movement requires descending input from the motor cortex and sensory feedback through the spinal cord. We previously developed a paired brain and spinal electrical stimulation approach in rats that relies on convergence of the descending motor and spinal sensory stimuli in the cervical cord. This approach strengthened sensorimotor circuits and improved volitional movement through associative plasticity. In humans, it is not known whether posterior epidural spinal cord stimulation targeted at the sensorimotor interface or anterior epidural spinal cord stimulation targeted within the motor system is effective at facilitating brain evoked responses. In 59 individuals undergoing elective cervical spine decompression surgery, the motor cortex was stimulated with scalp electrodes and the spinal cord was stimulated with epidural electrodes, with muscle responses being recorded in arm and leg muscles. Spinal electrodes were placed either posteriorly or anteriorly, and the interval between cortex and spinal cord stimulation was varied. Pairing stimulation between the motor cortex and spinal sensory (posterior) but not spinal motor (anterior) stimulation produced motor evoked potentials that were over five times larger than brain stimulation alone. This strong augmentation occurred only when descending motor and spinal afferent stimuli were timed to converge in the spinal cord. Paired stimulation also increased the selectivity of muscle responses relative to unpaired brain or spinal cord stimulation. Finally, clinical signs suggest that facilitation was observed in both injured and uninjured segments of the spinal cord. The large effect size of this paired stimulation makes it a promising candidate for therapeutic neuromodulation. KEY POINTS: Pairs of stimuli designed to alter nervous system function typically target the motor system, or one targets the sensory system and the other targets the motor system for convergence in cortex. In humans undergoing clinically indicated surgery, we tested paired brain and spinal cord stimulation that we developed in rats aiming to target sensorimotor convergence in the cervical cord. Arm and hand muscle responses to paired sensorimotor stimulation were more than five times larger than brain or spinal cord stimulation alone when applied to the posterior but not anterior spinal cord. Arm and hand muscle responses to paired stimulation were more selective for targeted muscles than the brain- or spinal-only conditions, especially at latencies that produced the strongest effects of paired stimulation. Measures of clinical evidence of compression were only weakly related to the paired stimulation effect, suggesting that it could be applied as therapy in people affected by disorders of the central nervous system.

Is neck pain treatable with surgery?

INTRODUCTION: Neck pain is one of the most common complaints in clinical practice and can be caused by a wide variety of conditions. While cervical spine surgery is a well-accepted option for radicular pain and myelopathy, surgery for isolated neck pain is controversial. The identification of the source of pain is challenging and subtle, and misdiagnosis can lead to inappropriate treatment. MATERIALS AND METHODS AND RESULTS: We conducted a thorough literature review to discuss and compare different causes of neck pain. We then supplemented the literature with our senior author's expert analysis of treating cervical spine pathology. CONCLUSIONS: This study provides an in-depth discussion of neck pain and its various presentations, as well as providing insight into treatment strategies and diagnostic pearls that may prevent mistreatment of cervical spine pathology.

Long-term results and surgical strategy development for degenerative disease treatment in athletes: a retrospective single-center study.

PURPOSE: To analyze of the results of spine surgical treatment of athletes with lumbar degenerative disease and development of a surgical strategy based on the preoperative symptoms and radiological changes in the lumbar spine. METHODS: For 114 athletes with lumbar degenerative disease were included in the present study. Four independent groups were studied: (1) microsurgical/endoscopic discectomy (n = 35); (2) PRP therapy in facet joints (n = 41); (3) total disc replacement (n = 11); (4) lumbar interbody fusion (n = 27). We evaluated postoperative clinical outcomes and preoperative radiological results. The average postoperative follow-up was 5 (3;6), 3.5 (3;5), 3 (2;4) and 4 (3;5) years, respectively. The analysis included an assessment of clinical outcomes (initial clinical symptoms, chronic pain syndrome level according to the VAS, quality of life according to the SF-36 questionnaire, degree of tolerance to physical activity according to the subjective Borg Rating of Perceived Exertion Scale) and radiological data (Dynamic Slip, Dynamic Segmental Angle, degenerative changes in the facet joint according to the Fujiwara classification and disc according to the Pfirrmann classification; changes in the diffusion coefficient using diffusion-weighted MRI). RESULTS: The median and 25-75% quartiles timing of return to sports were 12.6 (10.2;14.1), 2.8 (2.4;3.7), 9 (6;12), and 14 (9;17) weeks, respectively. We examined the type of surgical treatment utilized, as well as the preoperative clinical symptoms, severity of degenerative changes in the intervertebral disc and facet joint, the timing of return to sports, the level of pain syndrome, the quality of life according to SF-36, and the degree of tolerance to physical activity. We then developed a surgical strategy based on individual preoperative neurological function and lumbar morphological changes. CONCLUSIONS: In this retrospective study, we report clinical results of four treatment options of lumbar spine degenerative disease in athletes. The use of developed patient selection criteria for the analyzed surgical techniques is aimed at minimizing return-to-play times.

The Association Between Cervical Foraminal Stenosis and Adhesive Capsulitis: An Imaging-based Case-Control Study.

STUDY DESIGN: Retrospective single-center imaging-based case-control study. OBJECTIVE: To determine the association between cervical foraminal stenosis and adhesive capsulitis. SUMMARY OF BACKGROUND DATA: Patients with cervical spondylosis often exhibit shoulder symptoms. Cervical radiculopathies, particularly C5, can cause severe shoulder pain and reduced shoulder mobility, mimicking glenohumeral adhesive capsulitis (frozen shoulder), a common shoulder condition. This is the first study investigating the connection between adhesive capsulitis and cervical radiculopathy. METHODS: 438 patients who underwent glenohumeral hydrodistension between 2012 and 2019 were reviewed. Included were individuals with unilateral frozen shoulder investigated using ultrasound and cervical spine MRI to investigate cervical spondylosis. Foraminal stenosis at C3/4, C4/5, C5/6 and C6/7 was graded in axial T2 MRI, ipsilateral and contralateral to the adhesive capsulitis. The presence of foraminal stenosis ipsilateral to the frozen shoulder (cases) was compared with the contralateral side (control). McNemar's exact test was used to assess the strength of a correlation. RESULTS: Among 438 patients, 107 reported frozen shoulder and neck pain (24.5%), with 48 matching the study criteria. A significant association between ipsilateral frozen shoulder and C4/5 foraminal stenosis was observed (P=0.00000008636). Ipsilateral foraminal stenosis was observed in 57.3% of these cases, with bilateral stenosis in 29.1%. Additionally, 78% had neck pain on the same side as their frozen shoulder, and 44% had pain radiating to the shoulder. 48% patients underwent nerve-targeted interventions, with 44% addressing the C5 nerve (25% C5 steroid injection and 19% C4/5 anterior cervical discectomy and fusion). CONCLUSION: A substantial association between C5 foraminal stenosis and ipsilateral frozen shoulder was found. C5 radiculopathy could be a risk factor for "neurogenic frozen shoulder". Those diagnosing frozen shoulder and cervicobrachialgia should recognize that frozen shoulder and C5 radiculopathy may coexist. A multidisciplinary approach involving both shoulder and spine specialists is recommended for a definitive diagnosis.

Artificial Intelligence-Assisted MRI Diagnosis in Lumbar Degenerative Disc Disease: A Systematic Review.

STUDY DESIGN: Systematic review. OBJECTIVES: Lumbar degenerative disc disease (DDD) poses a significant global health care challenge, with accurate diagnosis being difficult using conventional methods. Artificial intelligence (AI), particularly machine learning and deep learning, offers promising tools for improving diagnostic accuracy and workflow in lumbar DDD. This study aims to review AI-assisted magnetic resonance imaging (MRI) diagnosis in lumbar DDD and discuss current research for clinical use. METHODS: A systematic search of electronic databases identified studies on AI applications in MRI-based lumbar DDD diagnosis, following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Search terms included combinations of "Artificial Intelligence," "Machine Learning," "Deep Learning," "Low Back Pain," "Lumbar," "Disc," "Degeneration," and "MRI," targeting studies in English from January 1, 2010, to January 1, 2024. Inclusion criteria encompassed experimental and observational studies in peer-reviewed journals. Data extraction focused on study characteristics, AI techniques, performance metrics, and diagnostic outcomes, with quality assessed using predefined criteria. RESULTS: Twenty studies met the inclusion criteria, employing various AI methodologies, including machine learning and deep learning, to diagnose lumbar DDD manifestations such as disc degeneration, herniation, and bulging. AI models consistently outperformed conventional methods in accuracy, sensitivity, and specificity, with performance metrics ranging from 71.5% to 99% across different diagnostic objectives. CONCLUSION: The algorithm model provides a structured framework for integrating AI into routine clinical practice, enhancing diagnostic precision and patient outcomes in lumbar DDD management. Further research and validation are needed to refine AI algorithms for real-world application in lumbar DDD diagnosis.

Prospective Randomized Comparison of Minimally Invasive Tlif versus Open Tlif: Clinical Effectiveness and Restoration of Working Capacity in Railway Workers.

STUDY DESIGN: Randomized Clinical Trial. OBJECTIVE: To compare the clinical efficacy and restoration of working capacity after MI (minimally invasive)-TLIF and O (open)-TLIF in railway workers with lumbar degenerative disease. METHODS: 83 patients, who were indicated for two-level lumbar decompression and fusion were randomly assigned to one of two groups: group 1 (n = 44) had MI-TLIF procedure and group 2 (n = 39) had O-TLIF procedure. The functional status was assessed using SF-36, ODI and VAS for back and leg pain, preoperatively, at discharge, and at 3, 6, and 12 months postoperatively. MRI and CT were obtained 1-year follow-up. The percentage of patients who returned to work at 1-year, work intensity and the time to return to work post-operatively were analyzed. RESULTS: At 1-year follow-up, the MI-TLIF group had significantly better ODI, VAS and SF-36 scores compared to the O-TLIF group. The postoperative MRIs revealed a statistically significantly less multifidus muscle atrophy in the MI group compared to the Open group. At 1-year follow-up, a comparable fusion ratio between MI group and Open group was recorded. After MI-TLIF procedure, depending on the workload, patients had a statistically significantly earlier return to work (P < .05) and statistically significantly higher return to work rate compared with the O-TLIF group (P < .05). CONCLUSIONS: The use of two-level MI-TLIF in railway workers has made it possible to significantly improve long-term clinical results, reduce the risk of surgical complications, muscle atrophy and time to return to work compared to O-TLIF.

Simultaneous Versus Staged Surgery For Double Crush Syndrome Of Cervical Radiculopathy And Peripheral Nerve Compression At The Wrist: A Retrospective Single-Center Study.

STUDY DESIGN: Retrospective single-center study. OBJECTIVES: to evaluate the results of surgical treatment in patients with double crush syndrome associated with cervical radiculopathy and upper limb peripheral nerve compression after staged and simultaneous operations. SUMMARY OF BACKGROUND DATA: Currently, choosing the optimal diagnostic and therapeutic modalities in treating patients with double crush syndrome remains unresolved. METHODS: The study included 79 patients with double crush syndrome (cervical radiculopathy and syndrome of Guyon's canal or Carpal tunnel syndrome). Two independent groups were studied: In the Staged Group (n=35), we performed a cervical decompression with stabilization and peripheral nerve decompression at separate days due to ongoing clinical symptoms (average interval between interventions being 22 (18;26) days). In the Simultaneous Group (n=33), we performed both the cervical spine surgery, as well as the peripheral nerve procedures in one surgical session. Total operative time, estimate blood loss, length of hospitalization, complications and clinical data (NDI score, SF-36, VAS neck pain score, VAS arm pain score, Disabilities of Arm, Shoulder and Hand (DASH) score, Macnab scale) were compared. We used the Mann-Whitney (MW) test for intergroup comparisons, Wilcoxon criterion for dependent samples, and Fisher's exact test for binomial parameters. RESULTS: There was a significantly lower operative time, duration of inpatient treatment and temporary disability in the Simultaneous Group (P=0.01, P=0.04 and P=0.006 respectively). Comparative analysis did not reveal significant intergroup differences using NDI, VAS and DASH (P>0.05), whereas, at discharge, significantly better clinical parameters were appreciated for the Simultaneous Group using SF-36 and Macnab scores (P=0.04 and P=0.03, respectively). At Last Follow-up, an intra-group analysis revealed comparable clinical effectiveness between the two approaches (P>0.05). CONCLUSION: Comparison of the effectiveness of simultaneous and staged surgery revealed comparable long-term clinical outcomes. However, simultaneous surgery conveys clinically important advantages in terms of surgical time, anesthesia duration, length of hospitalization and patient disability. LEVEL OF EVIDENCE: 3.

Patients May Return to Work Sooner After Laminoplasty: Occupational Outcomes of the Cervical Spondylotic Myelopathy Surgical Trial.

BACKGROUND AND OBJECTIVES: Return-to-work (RTW) is an important outcome for employed patients considering surgery for cervical spondylotic myelopathy (CSM). We conducted a post hoc analysis of patients as-treated in the Cervical Spondylotic Myelopathy Surgical Trial, a prospective, randomized trial comparing surgical approaches for CSM to evaluate factors associated with RTW. METHODS: In the trial, patients were randomized (2:3) to either anterior surgery (anterior cervical decompression/fusion [ACDF]) or posterior surgery (laminoplasty [LP], or posterior cervical decompression/fusion [PCDF], at surgeon's discretion). Work status was recorded at 1, 3, 6, and 12 months postoperatively. For patients working full-time or part-time on enrollment, time to RTW was compared across as-treated surgical groups using discrete-time survival analysis. Multivariate logistic regression was used to assess predictors of RTW. Clinical outcomes were compared using a linear mixed-effects model. RESULTS: A total of 68 (42%) of 163 patients were working preoperatively and were analyzed. In total, 27 patients underwent ACDF, 29 underwent PCDF, and 12 underwent LP. 45 (66%) of 68 patients returned to work by 12 months. Median time to RTW differed by surgical approach (LP = 1 month, ACDF = 3 months, PCDF = 6 months; P = .02). Patients with longer length-of-stay were less likely to be working at 1 month (odds ratio 0.51; 95% CI, 0.29-0.91; P = .022) and 3 months (odds ratio 0.39; 95% CI, 0.16-0.96; P = .04). At 3 months, PCDF was associated with lower Short-Form 36 physical component summary scores than ACDF (estimated mean difference [EMD]: 6.42; 95% CI, 1.4-11.4; P = .007) and LP (EMD: 7.98; 95% CI, 2.7-13.3; P = .003), and higher Neck Disability Index scores than ACDF (EMD: 12.48; 95% CI, 2.3-22.7; P = .01) and LP (EMD: 15.22; 95% CI, 2.3-28.1; P = .014), indicating worse perceived physical functioning and greater disability, respectively. CONCLUSION: Most employed patients returned to work within 1 year. LP patients resumed employment earliest, while PCDF patients returned to work latest, with greater disability at follow-up, suggesting that choice of surgical intervention may influence occupational outcomes.

Postoperative C5 Palsy after Anterior or Posterior Decompression for Degenerative Cervical Myelopathy: A Subgroup Analysis of the Multicenter, Prospective, Randomized, Phase III, CSM-Protect Clinical Trial.

STUDY DESIGN: Retrospective cohort study of prospectively accrued data. OBJECTIVE: To evaluate a large, prospective, multicentre dataset of surgically-treated DCM cases on the contemporary risk of C5 palsy with surgical approach. SUMMARY OF BACKGROUND DATA: The influence of surgical technique on postoperative C5 palsy after decompression for degenerative cervical myelopathy (DCM) is intensely debated. Comprehensive analyses are needed using contemporary data and accounting for covariates. METHODS: Patients with moderate to severe DCM were prospectively enrolled in the multicenter, randomized CSM-Protect clinical trial and underwent either anterior or posterior decompression between Jan 31, 2012, to May 16, 2017. The primary outcome was the incidence of postoperative C5 palsy, defined as onset of muscle weakness by at least one grade in manual muscle test at the C5 myotome with slight or absent sensory disruption after cervical surgery. Two comparative cohorts were made based on anterior or posterior surgical approach. Multivariate hierarchical mixed-effects logistic regression was used to estimate odds ratios (OR) with 95% confidence intervals (CI) for C5 palsy. RESULTS: A total of 283 patients were included, and 53.4% underwent posterior decompression. The total incidence of postoperative C5 palsy was 7.4% and was significantly higher in patients that underwent posterior decompression compared to anterior decompression (11.26% vs. 3.03%, P=0.008). After multivariable regression, posterior approach was independently associated with greater than four times the likelihood of postoperative C5 palsy (P=0.017). Rates of C5 palsy recovery were comparable between the two surgical approaches. CONCLUSION: The odds of postoperative C5 palsy are significantly higher after posterior decompression compared to anterior decompression for DCM. This may influence surgical decision-making when there is equipoise in deciding between anterior and posterior treatment options for DCM. LEVEL OF EVIDENCE: Therapeutic Level II.

Riluzole for Degenerative Cervical Myelopathy: A Secondary Analysis of the CSM-PROTECT Trial.

Importance: The modified Japanese Orthopaedic Association (mJOA) scale is the most common scale used to represent outcomes of degenerative cervical myelopathy (DCM); however, it lacks consideration for neck pain scores and neglects the multidimensional aspect of recovery after surgery. Objective: To use a global statistical approach that incorporates assessments of multiple outcomes to reassess the efficacy of riluzole in patients undergoing spinal surgery for DCM. Design, Setting, and Participants: This was a secondary analysis of prespecified secondary end points within the Efficacy of Riluzole in Surgical Treatment for Cervical Spondylotic Myelopathy (CSM-PROTECT) trial, a multicenter, double-blind, phase 3 randomized clinical trial conducted from January 2012 to May 2017. Adult surgical patients with DCM with moderate to severe myelopathy (mJOA scale score of 8-14) were randomized to receive either riluzole or placebo. The present study was conducted from July to December 2023. Intervention: Riluzole (50 mg twice daily) or placebo for a total of 6 weeks, including 2 weeks prior to surgery and 4 weeks following surgery. Main Outcomes and Measures: The primary outcome measure was a difference in clinical improvement from baseline to 1-year follow-up, assessed using a global statistical test (GST). The 36-Item Short Form Health Survey Physical Component Score (SF-36 PCS), arm and neck pain numeric rating scale (NRS) scores, American Spinal Injury Association (ASIA) motor score, and Nurick grade were combined into a single summary statistic known as the global treatment effect (GTE). Results: Overall, 290 patients (riluzole group, 141; placebo group, 149; mean [SD] age, 59 [10.1] years; 161 [56%] male) were included. Riluzole showed a significantly higher probability of global improvement compared with placebo at 1-year follow-up (GTE, 0.08; 95% CI, 0.00-0.16; P = .02). A similar favorable global response was seen at 35 days and 6 months (GTE for both, 0.07; 95% CI, -0.01 to 0.15; P = .04), although the results were not statistically significant. Riluzole-treated patients had at least a 54% likelihood of achieving better outcomes at 1 year compared with the placebo group. The ASIA motor score and neck and arm pain NRS combination at 1 year provided the best-fit parsimonious model for detecting a benefit of riluzole (GTE, 0.11; 95% CI, 0.02-0.16; P = .007). Conclusions and Relevance: In this secondary analysis of the CSM-PROTECT trial using a global outcome technique, riluzole was associated with improved clinical outcomes in patients with DCM. The GST offered probability-based results capable of representing diverse outcome scales and should be considered in future studies assessing spine surgery outcomes.

AO Spine Guideline for the Use of Osteobiologics (AOGO) in Anterior Cervical Discectomy and Fusion for Spinal Degenerative Cases.

STUDY DESIGN: Guideline. OBJECTIVES: To develop an international guideline (AOGO) about the use of osteobiologics in anterior cervical discectomy and fusion (ACDF) for treating degenerative spine conditions. METHODS: The guideline development process was guided by AO Spine Knowledge Forum Degenerative (KF Degen) and followed the Guideline International Network McMaster Guideline Development Checklist. The process involved 73 participants with expertise in degenerative spine diseases and surgery from 22 countries. Fifteen systematic reviews were conducted addressing respective key topics and evidence was collected. The methodologist compiled the evidence into GRADE Evidence-to-Decision frameworks. Guideline panel members judged the outcomes and other criteria and made the final recommendations through consensus. RESULTS: Five conditional recommendations were created. A conditional recommendation is about the use of allograft, autograft or a cage with an osteobiologic in primary ACDF surgery. Other conditional recommendations are about the use of osteobiologic for single- or multi-level ACDF, and for hybrid construct surgery. It is suggested that surgeons use other osteobiologics rather than human bone morphogenetic protein-2 (BMP-2) in common clinical situations. Surgeons are recommended to choose 1 graft over another or 1 osteobiologic over another primarily based on clinical situation, and the costs and availability of the materials. CONCLUSION: This AOGO guideline is the first to provide recommendations for the use of osteobiologics in ACDF. Despite the comprehensive searches for evidence, there were few studies completed with small sample sizes and primarily as case series with inherent risks of bias. Therefore, high-quality clinical evidence is demanded to improve the guideline.

Axis Screw Fixation ­ A Step-by-Step Review of the Surgical Techniques

In this article, we present the techniques of axis screw fixation (laminar, pars, pedicle and transarticular screws), discussing the indications and contraindications of each one, as well as surgical tips and anatomical landmarks.

No presente artigo, apresentamos as técnicas de fixação do áxis com parafusos (lamina, parafusos de pars, pedículo e transarticular), discutindos as indicações e contraindicações das mesmas, assim como dicas cirúrgicas e parâmetros anatômicos relevantes.