High-Resolution Spinal Motor Mapping Using Thoracic Spinal Cord Stimulation in Patients With Chronic Pain.

BACKGROUND: High-resolution spinal cord stimulation (HR-SCS) paddle can stimulate medial-dorsal columns and extend stimulation coverage to the laterally positioned spinal targets. OBJECTIVE: To investigate the medio-lateral selectivity of an HR-SCS paddle in patients with chronic pain. METHODS: During standard-of-care spinal cord stimulation (SCS) placement, epidurally evoked electromyography and antidromic dorsal column-evoked potentials were recorded in 12 subjects using an HR-SCS paddle with 8 medio-lateral sites spanning the full epidural width at thoracic T9-12 and a commercial paddle consecutively. RESULTS: Recruitment maps were aligned with respect to physiological midline which was overlapping with anatomic midline in 10 of 11 cases. Overlapping contacts between the HR-SCS and commercial paddles exhibited similar patterns while HR-SCS demonstrated higher precision targeting of certain dermatomes. Spinal motor maps showed that the lateral contacts triggered stronger responses in medial gastrocnemius, adductor magnus, and tibialis anterior while the medial contacts triggered stronger responses in gluteus maximus and adductor hallucis. The time-locked popliteal fossa responses indicated ipsilateral activation by HR-SCS at the lateral contacts and bilateral activation at the medial contacts with stronger ipsilateral responses. CONCLUSION: This study is the first to perform high-resolution medio-lateral SCS mapping in patients with chronic pain. These results show promise that HR-SCS may provide additional ipsilateral recruitment within the extremities which improve targeting of focal pain in the lower extremities. Furthermore, this study supports the functional use of intraoperative neuromonitoring as a decision tool to determine physiological midline in thoracic SCS surgeries and provides a full methodological framework.

Differences in EEG patterns between tonic and high frequency spinal cord stimulation in chronic pain patients.

OBJECTIVE: To investigate the differences in neural patterns between spinal cord stimulation (SCS) waveforms (60-Hz tonic vs 10-KHz high frequency stimulation, HFS) and their correlation to stimulation-induced pain relief. METHODS: We recorded 10-channel electroencephalogram (EEG) in response to stimulation ON and OFF in 9 chronic pain patients (4 women, 5 men) during SCS surgery and examined the intraoperative spatio-spectral EEG features. RESULTS: We discovered stronger relative alpha power in the somatosensory region and higher trend in alpha/theta peak power ratio in frontal cortex with HFS. We also observed a shift in peak frequency from theta to alpha rhythms in HFS as compared to baseline and tonic stimulation, where slower theta activity was maintained. Further, a positive correlation was found between changes in Oswestry disability index (ODI) scores (from preoperative to postoperative) and HFS-induced alpha/theta peak power ratio in frontal and somatosensory regions. CONCLUSIONS: Altogether, our findings suggest that dynamic spectral interactions in theta-alpha band and their spatial distributions might be the first intraoperative neural signatures of pain relief induced by HFS in chronic pain. SIGNIFICANCE: Examining electrophysiological changes intraoperatively has a potential to elucidate response to SCS therapy prior to device selection, reducing the healthcare expenditures associated with failed implants.

The consultant practitioner: an evolving role to meet changing NHS needs.

Since the introduction of the consultant practitioner role, with its huge variability in purpose and context, it has had to evolve in response to the changing needs of the NHS to achieve sustainability and transformation of services. AIM: This article reflects on the relevance of the consultant practitioner role and the impact of an action learning set in hastening its evolution in one NHS foundation trust. METHOD: From a process of collective critical reflection on their practice, six consultant practitioners analysed the impact they have had on influencing services and empowerment of their patients. Additionally, they have analysed the impact of an externally facilitated action learning set as a catalyst for change. RESULTS: All six consultant practitioners recognised that working together through the learning set enabled them to be more influential and effective. It encouraged them to share their experiences of continuous service improvement and crystalised their views on the impact they have had in delivering the organisation's vision. CONCLUSION: From their critical reflection, the six consultant practitioners acknowledged the influence of the action learning set on accelerating their confidence and competence to lead, and evaluating new models of care delivery at scale and pace. They recognised how far they have travelled in achieving the four dimensions of the role and ultimately their impact on their local sustainability and transformation plan (STP) and their trust's vision.

Prospective Study of the Use of Intraoperative Neuromonitoring in Determining Post-Operative Energy Requirements and Physiologic Midline in Spinal Cord Stimulation.

BACKGROUND: Intraoperative neuromonitoring (IONM) through electromyography (EMG) studies has been shown to be a safe, effective way to determine the laterality of the spinal cord and guide electrode placement during spinal cord stimulation (SCS). However, the use of IONM to predict post-operative energy requirements and midline has not been examined and offers a new avenue to streamline programming and device selection. Further, the impact of cerebrospinal fluid (CSF) thickness on intraoperative and post-operative amplitudes is understood but has not been explicitly characterized. METHODS: A total of 24 patients undergoing SCS implantation for chronic pain had intraoperative EMG studies performed to determine physiologic midline. The intraoperative midline was compared to the midline determined on post-operative day 1 based on paresthesia patterns during programming. For patients who had thoracic leads placed, the amplitudes needed to induce abdominal and extremity lateralization during SCS placement were compared with the intensities needed to induce therapy at post-operative day 1. Additionally, we examined whether CSF thickness, body mass index, diabetes, drug use, and smoking correlated with intraoperative and post-operative amplitudes. RESULTS: Intraoperative EMG was able to predict post-operative paresthesia-based midline in 70.83% of patients. There was a statistically significant relationship between the intraoperative intensity needed to induce extremity lateralization with the post-operative intensity to induce therapy (p = 0.009) as well as the intraoperative intensity needed to stimulate abdominals with the post-operative intensity (p = 0.033). There was also a relationship seen between CSF thickness and the post-operative energy requirements in patients (p = 0.039). DISCUSSION: EMG accurately predicts post-operative energy requirements and midline in SCS patients. While 29.17% of patients did not have a match between their intraoperative and post-operative midlines, EMG testing was still valuable in guiding electrode placement and providing information to predict post-operative intensities. Additionally, CSF thickness correlated with amplitude settings on the first post-operative day.

Supporting clinical leadership through action: The nurse consultant role.

AIMS AND OBJECTIVES: To evaluate the effectiveness of an action learning set to enhance clinical leadership and extend their scope and confidence more strategically. BACKGROUND: As the most senior clinical role in most healthcare systems, the consultant nurse role is a solitary one. They are required to develop personal resilience, commitment and a belief in their ability to lead, with new consultants needing a strong support network to succeed. DESIGN: Following a 2-year action learning set, four nurse consultants, one therapy consultant, and a university educationalist engaged in a cooperative inquiry approach using four cycles of discussion, reflection, analysis and action over an 18-month period from March 2015-July 2016, to learn how to change and enhance their working practices. Data were analysed thematically. RESULTS: Four themes emerged where the action learning set (i) offered structure and support, (ii) enabled a wider influence and (iii) empowered them to lead. The cooperative inquiry helped them realise how much they had gained from their collective learning and they felt empowered to lead. CONCLUSION: Their motivation to "make a difference" remains palpable. The outcomes of the cooperative inquiry included an enhanced understanding of the importance of openness and trust and a willingness to share and learn from each other in a respectful and confidential environment with a receptiveness to change. Self-leadership has clearly been accepted and embraced, and their collaboration has improved communication across the organisation, enhanced their strategic leadership capability and given confidence to disseminate externally. RELEVANCE TO CLINICAL PRACTICE: The action learning set offered structure to support these clinical leaders to keep them focused across the breadth of their role. Additionally, peer review with external facilitation has enabled these clinical leaders to gain a wider influence and empowered them to lead.