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1.
J Neurosurg Spine ; : 1-11, 2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34678778

RESUMO

OBJECTIVE: Nerve transfers are increasingly being utilized in the treatment of chronic tetraplegia, with increasing literature describing significant improvements in sensorimotor function up to years after injury. However, despite technical advances, clinical outcomes remain heterogenous. Preoperative electrodiagnostic testing is the most direct measure of nerve health and may provide prognostic information that can optimize preoperative patient selection. The objective of this study in patients with spinal cord injury (SCI) was to determine various zones of injury (ZOIs) via electrodiagnostic assessment (EDX) to predict motor outcomes after nerve transfers in tetraplegia. METHODS: This retrospective review of prospectively collected data included all patients with tetraplegia from cervical SCI who underwent nerve transfer at the authors' institution between 2013 and 2020. Preoperative demographic data, results of EDX, operative details, and postoperative motor outcomes were extracted. EDX was standardized into grades that describe donor and recipient nerves. Five zones of SCI were defined. Motor outcomes were then compared based on various zones of innervation. RESULTS: Nineteen tetraplegic patients were identified who underwent 52 nerve transfers targeting hand function, and 75% of these nerve transfers were performed more than 1 year postinjury, with a median interval to surgery following SCI of 24 (range 8-142) months. Normal recipient compound muscle action potential and isolated upper motor neuron injury on electromyography (EMG) were associated with greater motor recovery. When nerve transfers were stratified based on donor EMG, greater motor gains were associated with normal than with abnormal donor EMG motor unit recruitment patterns. When nerve transfers were separated based on donor and recipient nerves, normal flexor donors were more crucial than normal extensor donors in powering their respective flexor recipients. CONCLUSIONS: This study elucidates the relationship of the preoperative innervation zones in SCI patients to final motor outcomes. EDX studies can be used to tailor surgical therapies for nerve transfers in patients with tetraplegia. The authors propose an algorithm for optimizing nerve transfer strategies in tetraplegia, whereby understanding the ZOI and grade of the donor/recipient nerve is critical to predicting motor outcomes.

2.
Front Neurosci ; 15: 758427, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34690689

RESUMO

Objective: Intuitive control of conventional prostheses is hampered by their inability to provide the real-time tactile and proprioceptive feedback of natural sensory pathways. The macro-sieve electrode (MSE) is a candidate interface to amputees' truncated peripheral nerves for introducing sensory feedback from external sensors to facilitate prosthetic control. Its unique geometry enables selective control of the complete nerve cross-section by current steering. Unlike previously studied interfaces that target intact nerve, the MSE's implantation requires transection and subsequent regeneration of the target nerve. Therefore, a key determinant of the MSE's suitability for this task is whether it can elicit sensory percepts at low current levels in the face of altered morphology and caliber distribution inherent to axon regeneration. The present in vivo study describes a combined rat sciatic nerve and behavioral model developed to answer this question. Approach: Rats learned a go/no-go detection task using auditory stimuli and then underwent surgery to implant the MSE in the sciatic nerve. After healing, they were trained with monopolar electrical stimuli with one multi-channel and eight single-channel stimulus configurations. Psychometric curves derived by the method of constant stimuli (MCS) were used to calculate 50% detection thresholds and associated psychometric slopes. Thresholds and slopes were calculated at two time points 3 weeks apart. Main Results: For the multi-channel stimulus configuration, the average current required for stimulus detection was 19.37 µA (3.87 nC) per channel. Single-channel thresholds for leads located near the nerve's center were, on average, half those of leads located near the periphery (54.92 µA vs. 110.71 µA, or 10.98 nC vs. 22.14 nC). Longitudinally, 3 of 5 leads' thresholds decreased or remained stable over the 3-week span. The remaining two leads' thresholds increased by 70-74%, possibly due to scarring or device failure. Significance: This work represents an important first step in establishing the MSE's viability as a sensory feedback interface. It further lays the groundwork for future experiments that will extend this model to the study of other devices, stimulus parameters, and task paradigms.

3.
J Neurosurg Spine ; : 1-10, 2021 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-34715673

RESUMO

OBJECTIVE: Minimally invasive surgery (MIS) techniques can effectively stabilize and decompress many thoracolumbar injuries with decreased morbidity and tissue destruction compared with open approaches. Nonetheless, there is limited direction regarding the breadth and limitations of MIS techniques for thoracolumbar injuries. Consequently, the objectives of this study were to 1) identify the range of current practice patterns for thoracolumbar trauma and 2) integrate expert opinion and literature review to develop an updated treatment algorithm. METHODS: A survey describing 10 clinical cases with a range of thoracolumbar injuries was sent to 12 surgeons with expertise in spine trauma. The survey results were summarized using descriptive statistics, along with the Fleiss kappa statistic of interrater agreement. To develop an updated treatment algorithm, the authors used a modified Delphi technique that incorporated a literature review, the survey results, and iterative feedback from a group of 14 spine trauma experts. The final algorithm represented the consensus opinion of that expert group. RESULTS: Eleven of 12 surgeons contacted completed the case survey, including 8 (73%) neurosurgeons and 3 (27%) orthopedic surgeons. For the 4 cases involving patients with neurological deficits, nearly all respondents recommended decompression and fusion, and the proportion recommending open surgery ranged from 55% to 100% by case. Recommendations for the remaining cases were heterogeneous. Among the neurologically intact patients, MIS techniques were typically recommended more often than open techniques. The overall interrater agreement in recommendations was 0.23, indicating fair agreement. Considering both literature review and expert opinion, the updated algorithm indicated that MIS techniques could be used to treat most thoracolumbar injuries. Among neurologically intact patients, percutaneous instrumentation without arthrodesis was recommended for those with AO Spine Thoracolumbar Classification System subtype A3/A4 (Thoracolumbar Injury Classification and Severity Score [TLICS] 4) injuries, but MIS posterior arthrodesis was recommended for most patients with AO Spine subtype B2/B3 (TLICS > 4) injuries. Depending on vertebral body integrity, anterolateral corpectomy or mini-open decompression could be used for patients with neurological deficits. CONCLUSIONS: Spine trauma experts endorsed a range of strategies for treating thoracolumbar injuries but felt that MIS techniques were an option for most patients. The updated treatment algorithm may provide a foundation for surgeons interested in safe approaches for using MIS techniques to treat thoracolumbar trauma.

4.
Neurosurg Clin N Am ; 32(4): 473-481, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34538473

RESUMO

Cervical total disc replacement (CTDR) has gained popularity over the last 2 decades. It is a motion-preserving option to ACDF and is becoming more popular with patients and surgeons alike. Understanding complications that are unique to CTDR is crucial to performing successful, durable surgery. Careful patient selection and meticulous surgical technique are key to reducing complications associated with the surgery. Patient's should be followed closely after surgery with routine flexion/extension x-rays for early detection of any complications that may occur. Most complications can be observed with close follow-up. However, it is incumbent on the surgeon to recognize when revision surgery is necessary.


Assuntos
Degeneração do Disco Intervertebral , Fusão Vertebral , Substituição Total de Disco , Vértebras Cervicais/diagnóstico por imagem , Vértebras Cervicais/cirurgia , Discotomia , Seguimentos , Humanos , Degeneração do Disco Intervertebral/cirurgia , Substituição Total de Disco/efeitos adversos , Resultado do Tratamento
5.
J Neurosurg Spine ; : 1-9, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34560659

RESUMO

OBJECTIVE: The Affordable Care Act expanded Medicaid eligibility in many states, improving access to some forms of elective healthcare in the United States. Whether this effort increased access to elective spine surgical care is unknown. This study's objective was to evaluate the impact of Medicaid expansion under the Affordable Care Act on the volume and payer mix of elective spine surgery in the United States. METHODS: This study evaluated elective spine surgical procedures performed from 2011 to 2016 and included in the all-payer State Inpatient Databases of 10 states that expanded Medicaid access in 2014, as well as 4 states that did not expand Medicaid access. Adult patients aged 18-64 years who underwent elective spine surgery were included. The authors used a quasi-experimental difference-in-difference design to evaluate the impact of Medicaid expansion on hospital procedure volume and payer mix, independent of time-dependent trends. Subgroup analysis was conducted that stratified results according to cervical fusion, thoracolumbar fusion, and noninstrumented surgery. RESULTS: The authors identified 218,648 surgical procedures performed in 10 Medicaid expansion states and 118,693 procedures performed in 4 nonexpansion states. Medicaid expansion was associated with a 17% (95% CI 2%-35%, p = 0.03) increase in mean hospital spine surgical volume and a 23% (95% CI -0.3% to 52%, p = 0.054) increase in Medicaid volume. Privately insured surgical volumes did not change significantly (incidence rate ratio 1.13, 95% CI -5% to 34%, p = 0.18). The increase in Medicaid volume led to a shift in payer mix, with the proportion of Medicaid patients increasing by 6.0 percentage points (95% CI 4.1-7.0, p < 0.001) and the proportion of private payers decreasing by 6.7 percentage points (95% CI 4.5-8.8, p < 0.001). Although the magnitude of effects varied, these trends were similar across procedure subgroups. CONCLUSIONS: Medicaid expansion under the Affordable Care Act was associated with an economically and statistically significant increase in spine surgery volume and the proportion of surgical patients with Medicaid insurance, indicating improved access to care.

6.
Front Neurol ; 12: 669076, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34335444

RESUMO

Chronic low back pain (LBP) is one of the leading causes of disability worldwide. While LBP research has largely focused on the spine, many studies have demonstrated a restructuring of human brain architecture accompanying LBP and other chronic pain states. Brain imaging presents a promising source for discovering noninvasive biomarkers that can improve diagnostic and prognostication outcomes for chronic LBP. This study evaluated graph theory measures derived from brain resting-state functional connectivity (rsFC) as prospective noninvasive biomarkers of LBP. We also proposed and tested a hybrid feature selection method (Enet-subset) that combines Elastic Net and an optimal subset selection method. We collected resting-state functional MRI scans from 24 LBP patients and 27 age-matched healthy controls (HC). We then derived graph-theoretical features and trained a support vector machine (SVM) to classify patient group. The degree centrality (DC), clustering coefficient (CC), and betweenness centrality (BC) were found to be significant predictors of patient group. We achieved an average classification accuracy of 83.1% (p < 0.004) and AUC of 0.937 (p < 0.002), respectively. Similarly, we achieved a sensitivity and specificity of 87.0 and 79.7%. The classification results from this study suggest that graph matrices derived from rsFC can be used as biomarkers of LBP. In addition, our findings suggest that the proposed feature selection method, Enet-subset, might act as a better technique to remove redundant variables and improve the performance of the machine learning classifier.

7.
Neurosurg Focus ; 51(2): E10, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34333484

RESUMO

OBJECTIVE: Augmented reality (AR) is an emerging technology that has great potential for guiding the safe and accurate placement of spinal hardware, including percutaneous pedicle screws. The goal of this study was to assess the accuracy of 63 percutaneous pedicle screws placed at a single institution using an AR head-mounted display (ARHMD) system. METHODS: Retrospective analyses were performed for 9 patients who underwent thoracic and/or lumbar percutaneous pedicle screw placement guided by ARHMD technology. Clinical accuracy was assessed via the Gertzbein-Robbins scale by the authors and by an independent musculoskeletal radiologist. Thoracic pedicle subanalysis was also performed to assess screw accuracy based on pedicle morphology. RESULTS: Nine patients received thoracic or lumbar AR-guided percutaneous pedicle screws. The mean age at the time of surgery was 71.9 ± 11.5 years and the mean number of screws per patient was 7. Indications for surgery were spinal tumors (n = 4, 44.4%), degenerative disease (n = 3, 33.3%), spinal deformity (n = 1, 11.1%), and a combination of deformity and infection (n = 1, 11.1%). Presenting symptoms were most commonly low-back pain (n = 7, 77.8%) and lower-extremity weakness (n = 5, 55.6%), followed by radicular lower-extremity pain, loss of lower-extremity sensation, or incontinence/urinary retention (n = 3 each, 33.3%). In all, 63 screws were placed (32 thoracic, 31 lumbar). The accuracy for these screws was 100% overall; all screws were Gertzbein-Robbins grade A or B (96.8% grade A, 3.2% grade B). This accuracy was achieved in the thoracic spine regardless of pedicle cancellous bone morphology. CONCLUSIONS: AR-guided surgery demonstrated a 100% accuracy rate for the insertion of 63 percutaneous pedicle screws in 9 patients (100% rate of Gertzbein-Robbins grade A or B screw placement). Using an ARHMS system for the placement of percutaneous pedicle screws showed promise, but further validation using a larger cohort of patients across multiple surgeons and institutions will help to determine the true accuracy enabled by this technology.


Assuntos
Realidade Aumentada , Parafusos Pediculares , Fusão Vertebral , Cirurgia Assistida por Computador , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Estudos Retrospectivos
8.
Spine J ; 2021 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-34161844

RESUMO

BACKGROUND CONTEXT: There is growing interest among payers in profiling hospital value and quality-of-care, including both the cost and safety of common surgeries, such as lumbar fusion. Nonetheless, there is sparse evidence describing the statistical reliability of such measures when applied to lumbar fusion for spondylolisthesis. PURPOSE: To evaluate the reliability of 90-day inpatient hospital costs, overall complications, and rates of serious complications for profiling hospital performance in lumbar fusion surgery for spondylolisthesis. STUDY DESIGN/SETTING: Data for this analysis came from State Inpatient Databases from nine states made available through the Healthcare Cost and Utilization Project. PATIENT SAMPLE: Patients undergoing elective lumbar spine fusion for spondylolisthesis from 2010 to 2017 in participating states. OUTCOME MEASURES: Statistical reliability, defined as the ability to distinguish true performance differences across hospitals relative to statistical noise. Reliability was assessed separately for 90-day inpatient costs (standardized across years to 2019 dollars), overall complications, and serious complication rates. METHODS: Statistical reliability was measured as the amount of variation between hospitals relative to the total amount of variation for each measure. Total variation includes both between-hospital variation ("signal") and within-hospital variation ("statistical noise"). Thus, reliability equals signal over (signal plus noise) and ranges from 0 to 1. To adjust for differences in patient-level risk and procedural characteristics, hierarchical linear and logistic regression models were created for the cost and complication outcomes. Random hospital intercepts were used to assess between-hospital variation. We evaluated the reliability of each measure by study year and examined the number of hospitals meeting different thresholds of reliability by year. RESULTS: We included a total of 66,571 elective lumbar fusion surgeries for spondylolisthesis performed at 244 hospitals during the study period. The mean 90-day hospital cost was $30,827 (2019 dollars). 12.0% of patients experienced a complication within 90 days of surgery, including 7.8% who had a serious complication. The median reliability of 90-day cost ranged from 0.97to 0.99 across study years, and there was a narrow distribution of reliability values. By comparison, the median reliability for the overall complication metric ranged from 0.22 to 0.44, and the reliability of the serious complication measure ranged from 0.30 to 0.49 across the study years. At least 96% of hospitals had high (> 0.7) reliability for cost in any year, whereas only 0-9% and 0-11% of hospitals reached this cutoff for the overall and serious complication rate in any year, respectively. By comparison, 10%-69% of hospitals per year achieved a more moderate threshold of 0.4 reliability for overall complications, compared to 21%-80% of hospitals who achieved this lower reliability threshold for serious complications. CONCLUSIONS: 90-day inpatient costs are highly reliable for assessing variation across hospitals, whereas overall and serious complications are only moderately reliable for profiling performance. These results support the viability of emerging bundled payment programs that assume true differences in costs of care exist across hospitals.

9.
Global Spine J ; : 21925682211008424, 2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-33973491

RESUMO

STUDY DESIGN: Narrative review. OBJECTIVES: There is growing interest in the use of biomedical informatics and data analytics tools in spine surgery. Yet despite the rapid growth in research on these topics, few analytic tools have been implemented in routine spine practice. The purpose of this review is to provide a health information technology (HIT) roadmap to help translate data assets and analytics tools into measurable advances in spine surgical care. METHODS: We conducted a narrative review of PubMed and Google Scholar to identify publications discussing data assets, analytical approaches, and implementation strategies relevant to spine surgery practice. RESULTS: A variety of data assets are available for spine research, ranging from commonly used datasets, such as administrative billing data, to emerging resources, such as mobile health and biobanks. Both regression and machine learning techniques are valuable for analyzing these assets, and researchers should recognize the particular strengths and weaknesses of each approach. Few studies have focused on the implementation of HIT, and a variety of methods exist to help translate analytic tools into clinically useful interventions. Finally, a number of HIT-related challenges must be recognized and addressed, including stakeholder acceptance, regulatory oversight, and ethical considerations. CONCLUSIONS: Biomedical informatics has the potential to support the development of new HIT that can improve spine surgery quality and outcomes. By understanding the development life-cycle that includes identifying an appropriate data asset, selecting an analytic approach, and leveraging an effective implementation strategy, spine researchers can translate this potential into measurable advances in patient care.

10.
Neuron ; 109(9): 1426-1429, 2021 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-33957072

RESUMO

Chronic pain is a disabling disease with limited treatment options. While animal models have revealed important aspects of pain neurobiology, therapeutic translation of this knowledge requires our understanding of these cells and networks of pain in humans. We propose a multi-institutional collaboration to rigorously and ethically address this challenge.


Assuntos
Dor Crônica , Colaboração Intersetorial , Humanos
11.
Clin Spine Surg ; 34(8): E439-E449, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33979102

RESUMO

STUDY DESIGN: This was a retrospective clinical series. OBJECTIVE: The objective of this study was to evaluate radiologic changes in central spinal canal dimensions following minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) with placement of a static or an expandable interbody device. SUMMARY OF BACKGROUND DATA: MIS-TLIF is used to treat lumbar degenerative diseases and low-grade spondylolisthesis. MIS-TLIF enables direct and indirect decompression of lumbar spinal stenosis, with patients experiencing relief from radiculopathy and neurogenic claudication. However, the effects of MIS-TLIF on the central spinal canal are not well-characterized. MATERIALS AND METHODS: We identified patients who underwent MIS-TLIF for degenerative lumbar spondylolisthesis and concurrent moderate to severe spinal stenosis. We selected patients who had both preoperative and postoperative magnetic resonance imaging (MRI) and upright lateral radiographs of the lumbar spine. Measurements on axial T2-weighted MRI scans include anteroposterior and transverse dimensions of the dural sac and osseous spinal canal. Measurements on radiographs include disk height, neural foraminal height, segmental lordosis, and spondylolisthesis. We made pairwise comparisons between each of the central canal dimensions and lumbar sagittal segmental radiologic outcome measures relative to their corresponding preoperative values. Correlation coefficients were used to quantify the association between changes in lumbar sagittal segmental parameters relative to changes in radiologic outcomes of central canal dimensions. Statistical analysis was performed for "all patients" and further stratified by interbody device subgroups (static and expandable). RESULTS: Fifty-one patients (age 60.4 y, 68.6% female) who underwent MIS-TLIF at 55 levels (65.5% at L4-L5) were included in the analysis. Expandable interbody devices were used in 45/55 (81.8%) levels. Mean duration from surgery to postoperative MRI scan was 16.5 months (SD 11.9). MIS-TLIF was associated with significant improvements in dural sac dimensions (anteroposterior +0.31 cm, transverse +0.38 cm) and osseous spinal canal dimensions (anteroposterior +0.16 cm, transverse +0.32 cm). Sagittal lumbar segmental parameters of disk height (+0.56 cm), neural foraminal height (+0.35 cm), segmental lordosis (+4.26 degrees), and spondylolisthesis (-7.5%) were also improved following MIS-TLIF. We did not find meaningful associations between the changes in central canal dimensions relative to the corresponding changes in any of the sagittal lumbar segmental parameters. Stratified analysis by interbody device type (static and expandable) revealed similar within-group changes as in the overall cohort and minimal between-group differences. CONCLUSIONS: MIS-TLIF is associated with radiologic decompression of neural foraminal and central spinal canal stenosis. The mechanism for neural foraminal and central canal decompression is likely driven by a combination of direct and indirect corrective techniques.


Assuntos
Fusão Vertebral , Estenose Espinal , Constrição Patológica , Descompressão , Feminino , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos , Estudos Retrospectivos , Canal Medular/diagnóstico por imagem , Canal Medular/cirurgia , Estenose Espinal/diagnóstico por imagem , Estenose Espinal/cirurgia , Resultado do Tratamento
12.
Spine (Phila Pa 1976) ; 46(17): 1181-1190, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33826589

RESUMO

STUDY DESIGN: Retrospective analysis of administrative billing data. OBJECTIVE: To evaluate the extent to which a metric of serious complications determined from administrative data can reliably profile hospital performance in spine fusion surgery. SUMMARY OF BACKGROUND DATA: While payers are increasingly focused on implementing pay-for-performance measures, quality metrics must reliably reflect true differences in performance among the hospitals profiled. METHODS: We used State Inpatient Databases from nine states to characterize serious complications after elective cervical and thoracolumbar fusion. Hierarchical logistic regression was used to risk-adjust differences in case mix, along with variability from low case volumes. The reliability of this risk-stratified complication rate (RSCR) was assessed as the variation between hospitals that was not due to chance alone, calculated separately by fusion type and year. Finally, we estimated the proportion of hospitals that had sufficient case volumes to obtain reliable (>0.7) complication estimates. RESULTS: From 2010 to 2017 we identified 154,078 cervical and 213,133 thoracolumbar fusion surgeries. 4.2% of cervical fusion patients had a serious complication, and the median RSCR increased from 4.2% in 2010 to 5.5% in 2017. The reliability of the RSCR for cervical fusion was poor and varied substantially by year (range 0.04-0.28). Overall, 7.7% of thoracolumbar fusion patients experienced a serious complication, and the RSCR varied from 6.8% to 8.0% during the study period. Although still modest, the RSCR reliability was higher for thoracolumbar fusion (range 0.16-0.43). Depending on the study year, 0% to 4.5% of hospitals had sufficient cervical fusion case volume to report reliable (>0.7) estimates, whereas 15% to 36% of hospitals reached this threshold for thoracolumbar fusion. CONCLUSION: A metric of serious complications was unreliable for benchmarking cervical fusion outcomes and only modestly reliable for thoracolumbar fusion. When assessed using administrative datasets, these measures appear inappropriate for high-stakes applications, such as public reporting or pay-for-performance.Level of Evidence: 3.


Assuntos
Reembolso de Incentivo , Fusão Vertebral , Hospitais , Humanos , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Reprodutibilidade dos Testes , Estudos Retrospectivos , Fusão Vertebral/efeitos adversos
13.
Cureus ; 13(3): e13728, 2021 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-33842107

RESUMO

Background and objective High-frequency alternating current (HFAC) can yield a rapid-acting and reversible nerve conduction block. The present study aimed to demonstrate the successful implementation of HFAC block delivery via regenerative macro-sieve electrodes (MSEs). Methods Dual-electrode assemblies in two configurations [dual macro-sieve electrode-1 (DMSE-I), DMSE-II] were fabricated from pairs of MSEs and implanted in the transected and subsequently repaired sciatic nerves of two male Lewis rats. After four months of postoperative nerve regeneration through the MSEs' transit zones, the efficacy of acute HFAC block was tested for both configurations. Frequencies ranging from 10 kHz to 42 kHz, and stimulus amplitudes with peak-to-peak voltages ranging from 2 V to 20 V were tested. Evoked muscle force measurement was used to quantify the nerve conduction block. Results HFAC stimulation delivered via DMSE assemblies obtained a complete block at frequencies of 14 to 26 kHz and stimulus amplitudes of 12 to 20 V p-p. The threshold voltage for the complete block showed an approximately linear dependence on frequency. The threshold voltage for the partial conduction block was also approximately linear. For those frequencies that displayed both partial and complete block, the partial block thresholds were consistently lower. Conclusion This study provides a proof of concept that regenerative MSEs can achieve complete and reversible conduction block via HFAC stimulation of regenerated nerve tissue. A chronically interfaced DMSE assembly may thereby facilitate the inactivation of targeted nerves in cases wherein pathologic neuronal hyperactivity is involved.

14.
J Hand Surg Glob Online ; 3(1): 30-35, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33537663

RESUMO

Purpose: Increasing emphasis has been placed on multidisciplinary care for patients with traumatic brachial plexus injury (BPI), and there has been a growing appreciation for the impact of psychological and emotional components of recovery. Because surgeons are typically charged with leading the recovery phase of BPI, our objective was to build a greater understanding of surgeons' perspectives on the care of BPI patients and potential areas for improvement in care delivery. Methods: We conducted semistructured qualitative interviews with 14 surgeons with expertise in BPI reconstruction. The interview guide contained questions regarding the surgeons' practice and care team structure, their attitudes and approaches to psychological and emotional aspects of recovery, and their preferences for setting patient expectations. We used inductive thematic analysis to identify themes. Results: There was a high degree of variability in how surgeons addressed emotional and psychological aspects of recovery. Whereas some surgeons embraced the practice of addressing these components of care, others felt strongly that BPI surgeons should remain focused on technical aspects of care. Several participants described the emotional toll that caring for BPI patients can have on surgeons and how this concern has affected their approach to care. Surgeons also recognized the importance of setting preoperative expectations. There was an emphasis on setting low expectations in an attempt to minimize the risk for dissatisfaction. Surgeons described the challenges in effectively counseling patients about a condition that is prone to substantial injury heterogeneity and variability in functional outcomes. Conclusions: Our results demonstrate wide variability in how surgeons address emotional, psychological, and social barriers to recovery for BPI patients. Clinical relevance: Best practices for BPI care are difficult to establish because of the relative heterogeneity of neurologic injury, the unpredictable impact and recovery of the patient, and the substantial variability in physician approach to the care of these patients.

15.
Bone Jt Open ; 2(1): 9-15, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33537671

RESUMO

Aims: Brachial plexus injury (BPI) is an often devastating injury that affects patients physically and emotionally. The vast majority of the published literature is based on surgeon-graded assessment of motor outcomes, but the patient experience after BPI is not well understood. Our aim was to better understand overall life satisfaction after BPI, with the goal of identifying areas that can be addressed in future delivery of care. Methods: We conducted semi-structured interviews with 15 BPI patients after initial nerve reconstruction. The interview guide was focused on the patient's experience after BPI, beginning with the injury itself and extending beyond surgical reconstruction. Inductive and deductive thematic analysis was used according to standard qualitative methodology to better understand overall life satisfaction after BPI, contributors to life satisfaction, and opportunities for improvement. Results: Among the 15 patients interviewed, the following themes emerged: 1) happiness and life satisfaction were noted despite limitations in physical function; 2) quality of social support influences life satisfaction during recovery from BPI; and 3) social participation and having a sense of purpose impact life satisfaction during recovery from BPI. Conclusion: How patients perceive their BPI treatment and recovery varies widely, and is not directly linked to their self-reported functional outcome. Patients with stronger social circles and activities that give them a sense of fulfillment were more likely to be satisfied with their current status. Evaluating a patient's social network, goals, and potential supportive adaptations early in the treatment timeline through coordinated multidisciplinary care may improve overall satisfaction during recovery from BPI.Cite this article: Bone Joint Open 2020;2(1):9-15.

16.
J Neurosurg ; : 1-10, 2021 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-33578389

RESUMO

OBJECTIVE: The aim of this study was to examine the role of intraoperative neuromonitoring (IONM) during resection of benign peripheral nerve sheath tumors in achieving gross-total resection (GTR) and in reducing postoperative neurological complications. METHODS: Data from consecutive adult patients who underwent resection of a benign peripheral nerve sheath tumor at 7 participating institutions were combined. Propensity score matching was used to balance covariates. The primary outcomes of interest were the association between IONM and GTR and the association of IONM and the development of a permanent postoperative neurological complication. The secondary outcomes of interest were the association between IONM and GTR and the association between IONM and the development of a permanent postoperative neurological complication in the subgroup of patients with tumors involving a motor or mixed nerve. Univariate and multivariate logistic regression were then performed on the propensity score-matched samples to assess the ability of the independent variables to predict the outcomes of interest. RESULTS: A total of 337 patients who underwent resection of benign nerve sheath tumors were included. In multivariate analysis, the use of IONM (OR 0.460, 95% CI 0.199-0.978; p = 0.047) was a significant negative predictor of GTR, whereas none of the variables, including IONM, were associated with the occurrence of a permanent postoperative neurological complication. Within the subgroup of motor/mixed nerve tumors, in the multivariate analysis, IONM (OR 0.263, 95% CI 0.096-0.723; p = 0.010) was a significant negative predictor of a GTR, whereas IONM (OR 3.800, 95% CI 1.925-7.502; p < 0.001) was a significant positive predictor of a permanent postoperative motor deficit. CONCLUSIONS: Overall, 12% of the cohort had a permanent neurological complication, with new or worsened paresthesias most common, followed by pain and then weakness. The authors found that formal IONM was associated with a reduced likelihood of GTR and had no association with neurological complications. The authors believe that these data argue against IONM being considered standard of care but do not believe that these data should be used to universally argue against IONM during resection of benign nerve sheath tumors.

18.
Neuroimage Clin ; 29: 102530, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33338968

RESUMO

Chronic low back pain (LBP) is a very common health problem worldwide and a major cause of disability. Yet, the lack of quantifiable metrics on which to base clinical decisions leads to imprecise treatments, unnecessary surgery and reduced patient outcomes. Although, the focus of LBP has largely focused on the spine, the literature demonstrates a robust reorganization of the human brain in the setting of LBP. Brain neuroimaging holds promise for the discovery of biomarkers that will improve the treatment of chronic LBP. In this study, we report on morphological changes in cerebral cortical thickness (CT) and resting-state functional connectivity (rsFC) measures as potential brain biomarkers for LBP. Structural MRI scans, resting state functional MRI scans and self-reported clinical scores were collected from 24 LBP patients and 27 age-matched healthy controls (HC). The results suggest widespread differences in CT in LBP patients relative to HC. These differences in CT are correlated with self-reported clinical summary scores, the Physical Component Summary and Mental Component Summary scores. The primary visual, secondary visual and default mode networks showed significant age-corrected increases in connectivity with multiple networks in LBP patients. Cortical regions classified as hubs based on their eigenvector centrality (EC) showed differences in their topology within motor and visual processing regions. Finally, a support vector machine trained using CT to classify LBP subjects from HC achieved an average classification accuracy of 74.51%, AUC = 0.787 (95% CI: 0.66-0.91). The findings from this study suggest widespread changes in CT and rsFC in patients with LBP while a machine learning algorithm trained using CT can predict patient group. Taken together, these findings suggest that CT and rsFC may act as potential biomarkers for LBP to guide therapy.


Assuntos
Dor Lombar , Biomarcadores , Mapeamento Encefálico , Humanos , Dor Lombar/diagnóstico por imagem , Aprendizado de Máquina , Imageamento por Ressonância Magnética
19.
HSS J ; 16(Suppl 2): 339-343, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33380966

RESUMO

Background: Brachial plexus injury (BPI) is a life-altering event, and surgical treatment of BPI is costly ($66 million nationwide in 2006 alone). Despite the sizable costs associated with surgically treated BPI, the incidence of such cases in adults in the USA remains unknown. Questions/Purposes: We sought to provide an estimate of the national incidence of surgically treated BPI in the USA and to determine whether changes have occurred over time. Methods: We sought to identify privately insured adults ages 18 through 64 years who underwent BPI surgery between 2008 and 2014 in the IBM® MarketScan® Commercial Database. We then extrapolated those data to the same age group in the general population (all insurance types were considered), using data from the National Health Interview Survey and a study on the proportion of BPI surgery cases covered by private insurance to estimate the national incidence. We also used the Cochran-Armitage trend test to evaluate for statistically significant changes in BPI incidence over time in MarketScan private insurance data. Results: We identified 966 patients surgically treated for BPI in the MarketScan database in the study period. The average annual incidence of surgically treated BPI in this population of privately insured patients was 0.64 per 100,000 (range, 0.38 to 1.03). When extrapolated to all payers, the average annual incidence was 0.89 per 100,000 people (range, 0.53 to 1.47). In the MarketScan data, there was a statistically significant overall increase in the incidence of surgically treated BPI from 2008 through 2014 (0.47 per 100,000 to 1.03 per 100,000). Conclusion: The estimated annual incidence of surgically treated BPI is 0.89 per 100,000 persons in the USA, and the incidence has increased over time. These findings can serve as a baseline for further studies of disease epidemiology and societal and financial impact.

20.
HSS J ; 16(Suppl 2): 468-474, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33380981

RESUMO

Background: Emotional and social characteristics may influence rehabilitation and recovery after traumatic brachial plexus injury. Purposes: We sought to investigate if traumatic brachial plexus injury patients have different levels of social support and employ distinct coping strategies from uninjured control subjects. In addition, we studied which coping strategies are more commonly used among traumatic brachial plexus injury patients. Methods: Questionnaires for social support (Interpersonal Support Evaluation List and Social Support Questionnaire) and coping strategies (Brief-Coping Orientation to Problems Experienced) were administered to traumatic brachial plexus injury patients and an age- and sex-matched volunteer cohort (without brachial plexus injury). Results: There were no differences in interpersonal support (mean [SD] = 26.0 [8.6], 26.5 [6.8]), number of persons available for emotional support, and satisfaction with support between traumatic brachial plexus injury patients (n = 36) and volunteers (n = 43). The following coping strategies were more common among traumatic brachial plexus injury patients: active coping, self-distraction, denial, behavioral disengagement, venting, planning, self-blame, and acceptance. Conclusion: Patients with traumatic brachial plexus injury have similar levels of social support as healthy volunteers but are more likely to use an array of coping strategies. Surgeons and other clinicians should be aware of coping strategies favored by patients, particularly the potential for behaviors detrimental to recovery such as behavioral disengagement, self-blame, and denial. This work will inform future investigations into the influence of social support and coping strategies on clinical outcomes after traumatic brachial plexus injury.

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