CNS Abstracts

Name:

Daniel Côté

Abstract Title:

Neurosurgical Guidance with Optical Techniques

Authors:

Daniel Côté, Damon De Paoli, Martin Parent

Affiliations:

Université Laval

Abstract:

Introduction: 
We have developed optical techniques that are compatible with DBS surgery to provide guidance in real-time during surgery. The optical signature of the tissue is used to identify the exact position of the tip of the electrode, thereby providing information that could supplement pre-op MRI.
Methods:
An optical fibre is modified to to condition the beam for spectroscopy. The beam is focussed into the tissue to a very small point (less than a few microns) for a very high spatial resolution. The light that is re-emitted from the tissue (through the Raman effect or the diffuse reflectance) is used to identify the tissue with various algorithms (principal components analysis and neural networks). The device is demonstrated in non-human primates.
Results:
Tissue is identified from the spectral signature, in a very short time. We can also identify blood vessels unambiguously. The optical fibre can be inserted in a standard DBS electrode without modifications.
Conclusion:
We can acquire data and identify the tissue using the spectral signatures of the tissue. A very high spatial resolution (several microns), complementary to pre-op MRI is obtained. We believe this technique is easily adapted to many surgeries.

Submission Type:

Poster/Oral

Name:

Line Jacques

Abstract Title:

Management of Chronic Pain Post Neurectomy: A Role for Dorsal Root Ganglion Stimulation

Authors:

Line Jacques

Affiliations:

UCSF University of California San Francisco

Abstract:

Management of chronic pain post neurectomy: a role for Dorsal Root Ganglion Stimulation
Chronic neuropathic pain may be iatrogenic or post traumatic and can be a disabling and crippling in some individuals. Patients may have significant sleep disturbances, experience socio-psychological changes, along with significant physical limitations. A combination of pharmacological treatments along with physical therapy and local infiltrations may be useful. In certain cases, surgical approaches including selective neurectomy can be effective; others will remain chronic and intractable despite all interventional measures.
Neurostimulation techniques that can include: spinal cord stimulation, peripheral nerve stimulation and most recently dorsal root ganglion stimulation have shown promising results in the treatment of chronic neuropathic pain.
Method:
Pre-operatively, 12 patients were screened for suitability for dorsal root ganglion stimulation after triple neurectomy for groin pain, superficial peroneal nerve neurectomy for ankle and foot pain, saphenous neurectomy for knee pain.
Quality of life scores, VAS, and paresthesia mapping were recorded as baseline parameters as well as post operatively. Up to 4 percutaneous leads were placed epidurally at the dorsal root ganglion.
Results:
Overall, pain and quality of life measures were reduced by greater than 50%.
Conclusions:
Dorsal root ganglion stimulation is a viable option in the treatment of chronic neuropathic pain and should be considered as part of the pain treatment algorithm when treating this challenging patient population.

Submission Type:

Poster/Oral

Name:

Line Jacques

Abstract Title:

The Role of the MRINeurogram in the Selection of Patients for Peripheral Nerve Stimulation

Authors:

Line Jacques

Affiliations:

UCSF University of California San Francisco

Abstract:

Background:
The majority of peripheral nerve surgical pathology requires a good understanding of the anatomy. The utility of high resolution imaging in one’s peripheral nerve practice, the technical and technological advances being made by collaborations of surgeons, clinicians, radiologists and imaging scientists in terms of imaging of peripheral nerves, is crucial for successful surgical interventions.
Understanding the use of high resolution imaging; preoperatively, intraoperatively and postoperatively will be discussed.
We will review our operative experiences and outcomes correlated to surgical peripheral nerve pathology, with a special focus on interesting and unique cases. The importance of imaging including ultrasound, MRI-Neurogram and Tractography prior and after the surgery, the use of intraoperative electrophysiology, the technical aspects with intraoperative pictures and pathology will be presented. 
Results:
Entrapment, iatrogenic, traumatic, vascular, neoplastic and painful syndrome pathologies will be reviewed. Successful surgeries can be achieved with the help of good imaging pre and intra operatively. Targeted interventions with smaller incisions are an achievable outcome. 
Conclusion:
Understanding of the imaging characteristics of the peripheral nerve pathology prior to the procedure, allows a better ability to evaluate the risk related to nerve dysfunction, the potential outcome post operatively.
Intraoperative nerve monitoring, ultrasound and the understanding of the pathology are important to the surgeon undertaking the peripheral nerve surgery including peripheral nerve stimulation
Finally the advancement of imaging and collaboration with our radiology colleagues may help to develop better surgical approaches and improve our treatment strategies for this challenging patient population.

Submission Type:

Oral/Poster

Name: C. Michael Honey

Abstract Title:

Vagal Nerve Stimulation for Rheumatoid Arthritis: Systematic Review

Authors:

C. Michael Honey

Affiliations:

University of Manitoba

Abstract:

Introduction:
Rheumatoid Arthritis (RA) is a prevalent autoimmune disease that results in damaging joint inflammation and often results in disability. In 2015 it was estimated that approximately 24.5 million individuals were affected worldwide, creating a significant burden to the health care system. At present there exists no cure and treatment is limited to symptom management and decelerating disease progression. Recently, Vagal Nerve Stimulation (VNS) has emerged as a potential candidate in the multimodal treatment of RA. Efferent vagal signals have been shown to suppress the release of pro-inflammatory cytokines through the ‘cholinergic anti-inflammatory pathway’. VNS provides a therapeutic potential of modulating this pathway. 
Methods:
We performed a systematic review of VNS in association with RA and its applicability in both the clinical and laboratory setting. We searched MEDLINE, SCOPUS, GlobalHealth, BIOSIS, EMBASE, and the Cochrane Databases from inception to February 2019. Seventeen Articles which examined the relationship between vagal tone, rheumatoid arthritis, the cholinergic anti-inflammatory pathway were included. A further two studies examined the direct relationship between stimulation of the cervical vagus nerve and its effect on the inflammatory reflex. 
Results:
The available literature suggests a relationship between vagal nerve stimulation and a down regulation of inflammatory pathways that can be potentially beneficial in the treatment of rheumatoid arthritis. 
Conclusion:
Currently VNS for RA should be considered experimental, requiring further validation and evaluation before widespread adoption. Nevertheless, clinicians in the Canadian Neuromodulation Society need to know that VNS for RA may be a new and potentially rapidly expanding field of neuromodulation.

Submission Type:

Poster

Name: Victoria Bains

Abstract Title:

Education Before Stimulation: A survey of Patients and Their Caregivers About Effectiveness of a Pre-Neuromodulation Education Session.

Authors:

Victoria Bains RN, Brianna Wolters RN, Kathryn Curtis PhD C.Psych, Lakshmi Matmari PT MScCh, Yasmine Hoydonckx MD FIPP, Anuj Bhatia MD FRCPC

Affiliations:

Spinal Cord and Peripheral Nerve Neuromodulation for Pain Program, Toronto Western Hospital and University of Toronto, Toronto, Ontario

Abstract:

Introduction:

Neuromodulation for pain is a complex intervention and its various aspects can be challenging to grasp for patients and their caregivers. A structured pre-neuromodulation education session (PNES) can improve knowledge, alleviate anxiety, and improve outcomes of neuromodulation trials and implants through active involvement of patients and caregivers.1 At our Institution, PNES is delivered by a multidisciplinary team including medicine, nursing,2 psychology and physiotherapy to all patients (and their caregivers) awaiting trial of neuromodulation for pain. The effectiveness of this approach in delivering the information and addressing knowledge gaps is not known.
Methods: Feedback is collected from all attendees (patients and their caregivers) through a structured survey administered at the end of the PNES. Questions in the survey address following aspects of the PNES: content, delivery, and interaction with the presenters. Attendees are also questioned about their understanding of their role in a neuromodulation trial and their confidence in using psychological skills to alleviate anxiety and pain. Finally, their awareness about the role of physiotherapy in assisting with both function and pain management is also ascertained. Data is collected through close- and open-ended questions. Correlation between survey responses and patient demographics (age, gender, type and duration of pain syndrome) will be performed during qualitative and quantitative analysis.
Results: We are currently in the process of analyzing data from fifty patients and caregivers who attended the PNES at our Institution. Results of this analysis will be presented at the meeting.
Conclusions: A survey of the pre-neuromodulation education session can help improve its quality and effectiveness while empowering the attendees. Patient- and caregiver-centric feedback is essential to enhancing the efficacy of neuromodulation for pain and in removing barriers to its success.

Submission Type:

Poster/Oral

Name:

Martin Parent

Abstract Title:

Post-Mortem Analysis of Parkinson's Disease Brains After 11 and 12 Years of Deep Brain Stimulation of the Subthalamic Nucleus

Authors:

Desmeules F, Lecours C, Carrondo Cottin S, Noecker A, Gould P, Saikali S, Langlois M, Tremblay ME, McIntyre C, Côté D, Prud'homme M, Cantin L, Parent M

Affiliations:

Université Laval, Case Western Reserve University

Abstract:

Objective:

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is widely used to alleviate motor symptoms of Parkinson’s disease (PD). Through these unique case studies, we aim to describe the fine alterations that were induced by chronic stimulation of brain tissue, and to correlate these changes with clinical outcomes and with estimation of current spreading obtained with patient-specific DBS computational modeling.

Methods:

We provide detailed analysis of 2 PD brains who underwent DBS for 11 and 12 years, the longest STN stimulation periods ever reported in the literature.

Results:

Clinical data indicate positive outcomes of DBS such as significant reduction of motor symptoms and dopamine medication. As expected, we observed a 300 μm-width gliosis around the implanted electrodes showing high immunoreactivity for GFAP, but also for PCNA and GDNF. In the STN stimulated area only, we identified GFAP+ astrocytes endowed with highly varicose processes that were in close apposition to GLUT1+ blood vessels, potentially involved in decreased permeability of the blood-brain barrier. We also found an increase of the length of GLUT1+ blood vessels in the STN stimulated area, compared to non-stimulated STN regions, the vast majority being immunoreactive for VEGF, indicating important DBS-mediated angiogenesis. A significant reduction of the number of Iba1+ microglia was also observed near the active contacts, the majority being non-phagocytic, supporting the hypothesis of altered neuroinflammation induced by DBS. The subventricular zone in these particular DBS implanted brains was thicker than in non- implanted PD brains and similar to non-pathological brains matched for age, sex and post-mortem delay, suggesting that DBS may restore normal cell proliferation known to be reduced in PD. Conclusion:

With these unique case studies, we hope to reach a better understanding of the long- term cellular and molecular changes induced by chronic DBS.

Submission Type:

Oral

Name:

Zelma Kiss

Abstract Title:

The Ethics of Neuromodulation in Canada: From Methods Patents to Rationing

Authors:

Kiss ZHT, Roskams-Edris D, Anderson-Redick S, Illes J

Affiliations:

Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary; Neuroethics Canada, UBC

Abstract:

Introduction:

There are several ethical issues facing Canadian neuromodulation. One we have studied recently is the rapidly growing number of patents on methods of modulating brain regions. The other involves the economics of neuromodulation, from rationing of implants in different provinces, to the burgeoning private sector using direct-to-consumer or clinical non-invasive stimulation techniques. Our AIM here is to present these topics to foster high-level neuroethics discussions among neuromodulation practitioners to hopefully influence public policy. 
Methods:

Legal literature was gathered from Google Scholar, Westlaw, and Lexis Nexis. Patent documents were gathered from Lens.org. Canadian-held US method patents on brain stimulation targets were identified and their pathways traced. Members of the Canadian Neuromodulation Society and stakeholders will be asked open-ended questions about their opinions on funding of devices to determine common themes. 
Results:

There has been a massive increase in US methods patents implicating brain regions over the past 20 years, with a wide variety of targets listed and claims made, many of which lack scientific credibility. Many are held by industry, however, about an equal number are held by university/hospital or physicians/researchers. Of the 22 patents originating with Canadian inventors, 10 were acquired by US companies of which 6 were used as security. We will further explore the flow of funding from patenting to gaining securities in the neuromodulation field. We will report on themes identified in a poll of neuromodulation practitioners in Canada. 
Conclusions:

The legal protections offered by patents will affect the future of neuromodulation. These effects will be both direct and indirect and will impact the lives of patients and the development of future treatments. As neuromodulation rapidly matures, it is important to consider these effects using principles of neuroethics in a forward thinking manner.

Submission Type:

Oral

Name:

Judy Illes

Abstract Title:

Readiness of Novel Neurointerventions for Neurologic Disorders: Key Stakeholder Perspectives

Authors:

Iris Coates McCall [1], Nir Lipsman [2,3,4], Patrick McDonald [1,5], Allison Bethune [3], Judy Illes [1]

Affiliations:

[1] Neuroethics Canada, Division of Neurology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada; [2] Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto, Canada. [3] Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, Canada. [4] Division of Neurosurgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada; [5] Division of Neurology, Department of Pediatrics, University of British Columbia and BC Children's Hospital, Vancouver, BC, Canada

Abstract:

Introduction:
First-in-human (FIH) trials are challenged by the inherent lack of available data on the nature and magnitude of potential risks. With what information, then, are decisions made and informed consent given to participate in a FIH neurosurgery? This qualitative research seeks to provide much needed data on the relatively underreported translational process for novel neurosurgeries by examining what factors key stakeholders – both providers and patients – consider when determining readiness of a novel neurointervention for translation FIH trials.

Methods:
We use semi-structured interviews and qualitative analytic techniques to identify decision-making factors for patients and clinicians regarding FIH neurointerventions. Purposive and snowball sampling were used. Interviews were conducted with surgeons, neurologists, psychiatrists, and research personnel involved with FIH trials, and with patients who opted for a novel neurointervention over an established procedure. Open-ended questions were asked about perceptions of risk, readiness, and invasiveness of novel neurointerventions, and the data were analyzed for these and other emerging themes.
Results:
Eleven patients and 5 clinicians were interviewed. Preliminary results indicate divergent values, priorities, and understanding between both clinicians and patients, and patients affected by different neurologic conditions. Notably, perceptions of invasiveness differed between clinicians and patients.
Conclusions:
This research fills gaps in knowledge about attributes of neuromodulatory interventions that stakeholders value in the translational FIH neurosurgery process. Findings of divergent goals and expectations must be addressed in the development of guidance documents for clinicians and decision aids for future patients.

Submission Type:

Oral/Poster

Name:

Vishal Varshney

Abstract Title:

Demographic Analysis of Spinal Cord Stimulation in the Calgary Neuromodulation Program

Authors:

Vishal Varshney, John X Pereira, Kelly Shinkaruk, Kara Hallett, Zelma HT Kiss

Affiliations:

University of Calgary, Calgary Chronic Pain Centre, Departments of Anesthesiology University of Calgary, Calgary Chronic Pain Centre, Department of Clinical Neurosciences University of Calgary

Abstract:

Sociodemographic factors are associated with different prevalence of chronic pain, and affect equitable access to resource-intensive care, such as spinal cord stimulation (SCS). To determine if our demographics are similar to reported data, we analysed the clinical features and demographics of patients who were trialed and implanted for SCS in the Calgary Neuromodulation Program (CNP). 
A retrospective analysis of all patients enrolled in the CNP (who received either a SCS trial or full system implant) from 2002 to 2018 was performed. Data were extracted for age, sex and chronic pain diagnosis. 
85 patients received a SCS trial or system implant. Ages ranged from 21-81 years (median age 50 years) and 56% were male, while 44% were female. Patients presented with the following disease classifications: failed back surgery syndrome (32.9%), complex regional pain syndrome (29.4%), peripheral neuropathy (21.2%), refractory angina (10.6%) and phantom limb pain (5.9%). No female patients presented with phantom limb pain or refractory angina during this timespan. 
Compared to the PROCESS study, the EMP3OWER study and other SCS referral population studies in North America, the CNP has patients with similar average age as these studies, however a larger percentage of male patients (43% male patients shown in a 2016 North American study). The population of Calgary in 2018 had a median age of 37.4 years, and slightly more females overall (50.1%). The program also sees a higher number of CRPS patients (29.4% compared to 6.1% in EMP3OWER study), and fewer patients presenting with peripheral neuropathies (21.2% compared to 32.3%). This may relate to the program’s historical referral base focusing on musculoskeletal pain and interventions for CRPS. Future directions for our neuromodulation program may involve diversifying our referral base, and providing more educational resources to referring physicians and patients to improve equitable access.

Submission Type:

Poster

Name:

Vishal Varshney

Abstract Title:

Factors and Variability in Canadian Spinal Cord Stimulation Trial Duration

Authors:

Vishal Varshney, Kara Hallet

Affiliations:

Department of Anesthesiology, University of Calgary; Calgary Chronic Pain Centre

Abstract:

Spinal cord stimulation (SCS) is used to treat various chronic pain conditions, where other pain therapies have failed. The technique to perform SCS involves placing percutaneous electrodes in the epidural space connected to an external pulse generator for a certain duration, as a trial to determine efficacy prior to permanent device implantation. Currently, there is extensive variability on this trial period duration, and no evidence-based consensus or guideline exists to determine what duration is optimal. 
In Canada, the resource-intensive nature of SCS in the context of our public health care system warrants a sufficient trial duration to justify its use as a viable treatment option. Our aims were to potentially develop a national SCS guideline, based on patient and health economic factors.
We surveyed Canadian pain centres using the Canadian Neuromodulation Society member database, asking the following questions: 
1)In patients with chronic pain, what percutaneous SCS trial duration do you use to determine success prior to full system implantation? (less than 5 days; 5-7 days; 8-14 days; more than 14 days)
2)How did you determine your trial duration length?
3)Where do you perform your percutaneous SCS trials? 
6 Canadian pain centres who use SCS responded. 4/6 centres perform trials lasting 8-14 days. Centres described their trial duration as being based on factors like “personal experience”, “arbitrary”, “tradition”, and “institutional preference”. All trials were performed in an operating room (OR) setting, with multiple centres expressing a preference to perform trials in an interventional suite setting if available.
Trial durations in Canada are variable between pain centres, and the reasons for trial duration are largely subjective and not based on evidence, guidelines, or objective factors. Moving trials from the OR to interventional suites may significantly reduce systemic healthcare costs and allow for more appropriate resource allocation.

Submission Type:

Poster

Name:

Caitlin Courchesne

Abstract Title:

Practice, Perceptions and Predictions: A Survey of North American Functional Neurosurgeons

Authors:

Laura Y. Cabrera (1), Caitlin Courchesne (2), Judy Illes (2)

Affiliations:

(1) Center for Ethics and Humanities in the Life Sciences, Michigan State, Lansing, MI, USA, (2) Neuroethics Canada, University of British Columbia, Vancouver, BC, Canada

Abstract:

Introduction:

A wide range surgical interventions are under investigation to remediate psychiatric conditions resistant to conventional pharmacologic therapy. Given the troubled history of psychosurgery and its renaissance today, we sought to gauge current attitudes among functional neurosurgeons about these techniques. 
Methods:

We designed a 51-question online survey and distributed it to members of the American Society for Stereotactic and Functional Neurosurgery. Descriptive statistical analysis was performed on the data obtained.
Results: We received 38 completed surveys (19% response rate). 50% (19) of responders reported using psychiatric neurosurgery interventions at least once per year in their clinical practice. Of those with experience performing psychiatric neurosurgery, 11 (58%) reported using both neuromodulatory and ablative interventions in their practice, 6 (32%) reported using neuro-modulatory interventions exclusively, and 2 (11%) reported using ablative or lesioning procedures exclusively. 71% of all respondents (27) supported the clinical utility of ablative surgery in modern neuropsychiatric practice, 87% (33) agreed that ablative procedures constitute a valid treatment alternative to deep brain stimulation, and 23 (61%) agreed that ablative surgery may be an acceptable treatment option for patients who are unlikely to comply with postoperative care. 95% (36) of functional neurosurgeons agreed that significant barriers exist for both patients and physicians who consider treatment with psychiatric neurosurgery. 
Conclusions:

These findings and prior studies suggest that stigma, historical misuse, unclear clinical indications, reluctance of colleagues to refer, and concerns about adverse effects all constitute barriers to the acceptance and clinical practice of psychiatric neurosurgery. Given both the potential benefits of these interventions and identified barriers, continued innovation on the psychiatric neurosurgery frontier is an imperative.

Submission Type:

Poster/Oral

Name:

Julia Kaal

Abstract Title:

The Clinical Research Landscape of Neuromodulation for the Treatment of Pediatric Drug Resistant Epilepsy

Authors:

K. Julia Kaal, MSc (1,2,3), Magda Aguiar, PhD (1,3), Mark Harrison, PhD (1,4), Patrick J. McDonald, MD, MHSc, FRCSC (3,5), Judy Illes, CM, PhDn (3)

Affiliations:

1. Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, 2. School of Population and Public Health, University of British Columbia, Vancouver, BC, 3. Neuroethics Canada, Division of Neurology, Department of Medicine, University of British Columbia, Vancouver, BC, 4. Centre for Health Evaluation and Outcome Sciences, St Paul’s Hospital, Vancouver, BC 5 Faculty of Medicine, Division of Neurosurgery, Department of Surgery University of British Columbia, Vancouver, BC

Abstract:

Introduction:

The rapid emergence of neurotechnologies over the past decade has compounded the complexity of decision-making in pediatric neurosurgery. Unlike new drugs, innovative neurosurgical treatments are less likely to undergo rigorous testing via RCTs, leaving physicians and parents with a knowledge gap regarding the efficacy, safety and long-term side effects. We aim to characterize the clinical research landscape of pediatric drug resistant epilepsy (DRE) with a focus on neuromodulating interventions, using data retrieved from the ClinicalTrials.gov registry.
Method:

We searched ClinicalTrials.gov using the terms ‘epilepsy’ and ‘drug resistant’, restricting age to 0-17 years. We included all trials and grouped them by intervention (i.e., neuromodulating intervention, device or diagnostic procedure, behavioral, drug, dietary). We conducted a comparative analysis with focus on key trial features such as age range, recruitment status and outcomes.
Results:

We identified 96 registered trials: 36 investigate a drug, 25 a neuromodulating intervention, and 15 a dietary therapy. Vagus nerve stimulation, transcranial direct current stimulation, deep brain stimulation represent 60% of the registered neuromodulating interventions. Of trials investigating this group of interventions, 10 are currently recruiting, 2 have not yet started recruiting, 8 are listed as complete or terminated, and 3 posted results. The eligible age ranges of trials vary significantly depending on the type of intervention. Seizure frequency is the most frequently measured outcome of interventional trials.
Conclusion:

The landscape of registered trials for pediatric DRE reflects a lag between clinical research and clinical practice, highlighting the need for timely evidence before novel interventions are adopted into clinical practice. Further research is also needed to determine if intervention endpoints reflect treatment attributes of highest priority to parents and physicians.

Submission Type:

Poster/Oral

Name:

Victoria Bains

Abstract title:

Are We Try(al)ing Hard Enough?: A Survey of Patients’ Experience with Triphasic SCS Trials for Pain Relief

Authors:

Victoria Bains RN, Brianna Wolters RN, Yasmine Hoydonckx MD FIPP, Anuj Bhatia MD FRCPC

Affiliations:

Spinal Cord and Peripheral Nerve Neuromodulation for Pain Program, Toronto Western Hospital and University of Toronto, Toronto, Ontario

Abstract:

Introduction:

A trial of spinal cord stimulation (SCS) is recommended to support the decision regarding an implant of the SCS system to relieve pain.1 Trialing affords the opportunity to assess SCS before committing to permanent implantation. At our Institution, a SCS trial is triphasic and lasts 12 days with patients experiencing tonic, placebo, and paresthesia-free modes, each for 4 days. We survey all patients who have undergone a trial of SCS with the goal of enhancing quality and minimizing adverse effects including expectation bias.
Methods:

In the survey, patients are asked about their level of knowledge regarding the SCS trial prior to its initiation. Patients are also questioned about their experiences during the three phases of the trial and whether they were able to discriminate between placebo and paresthesia-free stimulation. Other data collected during the survey includes patients’ level of comfort with the technological aspects of the trial. Finally, demographic data including age, gender, type and duration of pain syndrome, daily opioid dose, and the patient’s baseline psychological status are also collected.
Results:

We are currently in process of correlating and analyzing data for a total of forty patients that have had triphasic trials of SCS at our Institution. We intend to correlate data from the surveys with baseline demographic data and outcomes of the trial (successful with recommendation of SCS implant versus unsuccessful). The final analysis will be presented at the meeting.
Conclusions:

We believe the use of a questionnaire at the end of SCS trials will provide us with a better understanding of the patients’ experience. We will also cross-reference the data for any pattern differentiation between patients. Feedback from patients will also help us quantify the importance of including a placebo phase2 during the SCS trial.
References
1. Deer, et al. Neuromodulation 2014;17:515-50.
2. Al-Kaisy, et al. Neuromodulation 2018;21:

Submission Type:

Poster/Oral

Name:

Lutz Weise

Abstract title:

Influence of Disease Lateralization in Parkinson’s on Tractography and Electrophysiology Findings

Authors:

Lutz Weise, Ron Hill, Susan Morris, Erika Leck, Matthias Schmidt, Heather Rigby

Affiliations:

Division of Neurosurgery and Neurology and Neuroradiology, Dalhousie University, Halifax, Canada

Abstract:

Objectives:
Asymmetric motor symptoms are typical in Parkinsn’s disease (PD). The side of predominance may have implications on the course of the disease. 
Multiple imaging modalities (SPECT, PET, MRI) have demonstrated asymmetry in PD, such as motor cortex thinning in the hemisphere corresponding to the symptomatic side. 
The objective was to assess the correlation between lateralized symptoms and Diffusion Tensor Imaging (DTI) characteristics of the submotor area in Deep Brain Stimulation (DBS) candidates with PD and possible implications on DBS parameters.

Methods:
34 patients were included. Disease dominance was assessed based on UDPRS items. A 1cm3 subcortical region of interest (ROI) was positioned underneath the motor cortex. The primary outcome was the difference in fibers between the disease-dominant and non disease-dominant cortex. Fractional anisotropy (FA) and stimulation parameters (mA) were assessed. Statistical analysis comprised T-test, ANOVA, Pearson and Spearman correlation. 
Results: 
There was a higher number of fibers (p=0.0031) and FA (p=0.0427) in the submotor ROI corresponding to the disease dominant side. Based on 23 patients that were operated the threshold for stimulation-induced side effects on the left side was inversely correlated with the number of fibers in the left ROI (Spearman -0.497, p=0.0158).
Conclusion:
Surprisingly, DTI analysis showed increased fiber concentration and FA in the disease dominant hemisphere. The underlying pathophysiology remains unclear with the possibility of a compensatory mechanism or compacting of fibers underneath a shrinking motor cortex. The increased threshold for side effects in relation to decreased fibers could have implications in DBS planning.

Submission Type:

Poster/Oral

Name:

Roshini Jain

Abstract title:

Whisper RCT: An Updated Post-Hoc Evaluation Of Sub-Perception SCS AT ≤1.2 KHZ In Previously-Implanted Subjects

Authors:

James North, MD (1), WHISPER RCT Clinical Study Group, Lilly Chen, MD (2), Roshini Jain, MS (2)

Affiliations:

1. Carolinas Pain Institute, Winston-Salem, NC USA 2. Boston Scientific, Valencia, CA, USA.

Abstract:

Introduction:
Results from a recent randomized controlled trial (RCT) provided Level 1 evidence that equivalent pain relief using a range of frequencies from 1 to 10 kHz spinal cord stimulation (SCS) with appropriate neural dosing was achieved (Thomson SJ. et al. 2018). Furthermore, 1 kHz SCS required significantly less charge than higher frequencies. The WHISPER RCT evaluates safety and clinical effectiveness of sub-perception Spinal Cord Stimulation (SCS) at ≤1.2 kHz in subjects previously implanted with a SCS System for treatment of chronic, neuropathic pain.
Methods:
WHISPER is a prospective, multicenter RCT with a crossover design sponsored by Boston Scientific (ClinicalTrials.gov: NCT02314000). Subjects previously implanted with SCS and a baseline overall pain score ≥6 (with SCS off) at study start were enrolled. Eligible subjects were randomized to either receive sub-perception or supra-perception for a period of 90 days and then crossed over to receive vice versa. At completion of crossover, outcomes related to overall pain, satisfaction and preference were collected.
Results: 
The study met its primary endpoint, based on overall pain responder rate (≥ 50% improvement from Baseline) in a pre-specified cohort of 70 randomized subjects (interim analysis) who were previously implanted for ~4 years and with a mean disability score (Oswestry Disability Index) of 69.4. For those subjects using sub-perception SCS, significant pain relief was sustained (p < 0.001) at 1 year. Additionally, improvement in disability and treatment satisfaction was noted. Post-hoc analysis (n=140 randomized subjects) demonstrated that multiple options provided superior outcomes when subjects could choose the most effective option.
Conclusions:
The WHISPER study demonstrates that sub-perception SCS at ≤1.2 kHz is safe and effective, and that providing waveform options enables superior outcomes when subjects can choose their most effective form of neurostimulative therapy.

Submission Type:

Poster

Name:

Roshini Jain

Abstract title:

A Prospective Global Registry of Real-World Outcomes Using Spinal Cord Stimulation Systems For Chronic Pain

Authors:

Richard Rauck, MD (1), Simon Thomson, MBBS (2), RELIEF Clinical Study Group, Rex Woon, MS (3), Roshini Jain, MS (3)

Affiliations:

1. Carolinas Pain Institute, Winston-Salem, NC USA. 2. Basildon and Thurrock University Hospitals NHS, Basildon, UK 3. Boston Scientific, Valencia, CA USA.

Abstract:

Introduction:
Large patient outcome registries are a key part of the compendium of information typically mined to generate real-world data and evidence. Real world evidence (RWE) derived from such registries via application of advanced data analytics therefore represents a potentially important aspect of the on-going rational assessment and future development of commercially-available Spinal Cord Stimulation (SCS) devices. We present here a prospective global registry designed to evaluate long-term, clinical application of neurostimulation therapy for pain.
Methods:
This is a prospective, multicenter global registry (RELIEF Registry, Boston Scientific) that aims to assess several various aspects of the pain treatment experience and the safety profile associated with using SCS in up to 1700 participants at up to 81 centers (ClinicalTrials.gov Identifier: NCT01719055). Eligible study participants are trialed for “on label” use only with a commercially-approved SCS system (Boston Scientific) and must sign an IRB-approved informed consent form. All permanently-implanted subjects are followed out to 36-months.
Results: 
A total of 1,151 subjects have been assessed out to 3-years post-implantation. Patient satisfaction (PGIC) assessment determined that 88% of registry participants reported overall therapeutic improvement within the span of this 3-year duration. In addition, a low incidence of explants due to device-related complications of 7.9% was determined with only 2.4% indicating that this was due to inadequate pain relief (% explant per year: 3.6%). 
Discussion: 
Real-world evidence derived from large patient registries is needed to assess patient quality of life and device longevity when using SCS to treat chronic pain. The 3-year results of this prospective, real-world registry demonstrate a low percent explant rate per year and a high percentage of patients reporting therapeutic improvement when using an SCS device to treat their chronic pain.

Submission Type:

Poster

Name:

Roshini Jain

Abstract title:

Outcomes Following Utilization of a Device Adaptor in Previously-Implanted Patients Using SCS for Chronic Pain

Authors:

Thomas Yearwood, MD, PhD (1), Yu Pei, MPA (2), Roshini Jain, MS (2)

Affiliations:

1. Neuromodulation Specialists, Pascagoula, MS USA. 2. Boston Scientific Neuromodulation, Valencia, CA USA.

Abstract:

Introduction:
Patients using Spinal Cord Stimulation (SCS) systems who have endured problems with device longevity and/or loss of efficacy may be able to achieve better outcomes utilizing newer technologies that offer an increased variety of waveforms and programming options to address their chronic pain. In this retrospective study, we examined the outcomes of previously-implanted patients who went on to use a commercially-available adaptor enabling connection to an SCS system that offers multiple neurostimulation based treatment approaches to regain and maintain efficacious therapy. 
Methods:
This is a real-world, retrospective study of patients who were previously implanted with an SCS system (commercially-available SCS device, Abbott) who then went on to utilize an adaptor (Precision S8, Boston Scientific) to connect to a new SCS system capable of multiple modality stimulation and/or combination therapy. Pain relief and other associated outcomes with both previously-implanted SCS systems and newly connected commercially¬ available systems (Boston Scientific) are being collected.
Results:
Seven subjects were assessed at baseline and at post-implantation follow-up visits following use of a previously-implanted system and a newly-implanted system (current system) as facilitated by the utilization of an SCS device adaptor. An NRS mean score improvement of 4.7 ± 1.8 points was reported by patients using their current system versus an improvement of 2.7 ± 1.8 points when using their previous system. Five out of 7 patients assessed reported better pain relief after using the newly-implanted system, while the remaining 2 patients reported no change. 
Conclusions:
The outcomes of this small, multicenter observational case-series suggest that offering previously-implanted SCS patients a system capable of providing multiple waveforms may be helpful in salvaging or improving pain relief when using a commercially-available device adaptor.

Submission Type:

Poster

Name:

Roshini Jain

Abstract title:

Outcomes Using an SCS Device Capable of Delivering Combination Therapy (Stimulator Sequential) and Advanced Waveforms/Field Shapes

Authors:

Clark Metzger, MD (1), M.B. Hammond, PA (1), Stephen T. Pyles, MD (2), Anthony Berg, MD (3), Romanth Waghmarae, MD (4), James North, MD (5), Yu Pei, MPA (6), Roshini Jain, MS (6)

Affiliations:

1. NeuroMicroSpine, Pensacola, FL USA. 2. Pain Treatment Centers, Ocala, FL, USA. 3. Spine Team Texas, Rockwall, TX USA. 4. Advanced Pain And Wellness Institute, Williamsville, NY USA. 5. Carolinas Pain Institute, Winston-Salem, NC USA. 6. Boston Scientific, Valencia, CA USA.

Abstract:

Introduction:
Developing “all-in-one” spinal cord stimulation (SCS) systems with capability for multiple types of neurostimulation paradigms will likely empower patients to identify the best treatment approach suitable for their needs. In this report, we provide observed real-world outcomes in patients who used a new SCS system designed to combine multiple waveform availability, capable of sequential or simultaneous delivery of therapeutic neurostimulation, with an algorithm designed to enable highly manipulatable control of stimulation field shape.
Methods:
This is a consecutive, multi-center case-series of patients based on retrospective chart review as part of an ongoing real-world evaluation of SCS outcomes for chronic pain (Clinicaltrials.gov identifier: NCT01550575). Patients were treated with a newly designed SCS system (Precision Spectra WaveWriter, Boston Scientific) capable of combination therapy (sequential or simultaneous), multiple waveforms and advanced field shapes, and waveform automation for treatment of low back and/or leg pain. 
Results:
To date, 217 patients have been analyzed. A statistically significant improvement in overall targeted pain scores (NRS) at last follow-up was reported (Baseline NRS: 7.5; at last follow-up [96.6 ± 80.9 days] NRS: 2.4; p < 0.0001). Thirty-nine percent of all patients indicated >80% pain relief at their last follow-up. Twenty-two percent (48 of 217) of all patients reported being pain free (NRS = 0) at last follow-up. Updated data will be presented. 
Conclusions: 
These results provide support for the postulate that an SCS system designed to provide combination therapy, multiple waveform options, and enhanced anatomical targeting capabilities, allows for highly effective pain relief outcomes in a patient-specific manner within the real‑world clinical setting.

Submission Type:

Poster

Name:

Karen Waterhouse

Abstract title:

Hippocampal Deep Brain Stimulation for Intractable Epilepsy

Authors:

Karen Waterhouse, Aleksander Vitali, and Jose Tellez-Zenteno

Affiliations:

Royal University Hospital, Saskatoon, Sask.

Abstract:

Despite optimal medical treatment and even epilepsy surgery as many as 40% of patients with epilepsy continue to have a recurrence of seizures. For these patients, neurostimulation procedures are gaining interest. Deep brain stimulation (DBS) delivers electrical impulses to targeted areas of the brain to restore the balance of circuits that are disrupted. DBS has been shown as a productive intervention for seizure control in patients with drug resistant epilepsy.
This presentation will discuss our center's experience with Hippocampal Deep Brain Stimulation and will highlight the cases of 2 patients who received treatment with DBS after both had a failed response to antiepileptic drugs (AEDs) and a temporal lobectomy.

Submission Type:

Poster/Oral

Name:

David Brandman

Abstract title:

Rapidly Calibrating Intracortical Brain Computer Interfaces For Communication in Three People With Paralysis

Authors:

Brandman DM (1, 2), Harrison MH (3), Hochberg LR (2, 4)

Affiliations: (1)

Department of Surgery (Neurosurgery), Halifax, NS, (2) Carnie Institute for Brain Sciences, Brown University, Providence RI, (3) Department of Applied Math, Brown University, Providence RI, (4) Neurology, Harvard Medical School, Boston MA

Abstract:

Introduction:

Intracortical brain-computer interfaces can enable individuals with paralysis to communicate and control external devices using intuitive motor imagery. Much progress has been made in improving the quality and robustness of neural control; however, less research has focused on optimizing calibration. We sought to quantify how much time was required to acquire state-of-the-art cursor control using a closed-loop calibration paradigm.
Methods:

Three people with cervical AIS-A spinal cord injuries underwent surgical placement of two 96-channel intracortical silicon microelectrode arrays. Raw neural signals for each electrode were sampled at 30 kHz using the NeuroPort System (Blackrock Microsystems, Salt Lake City, UT). We extracted: (1) the rate of threshold crossings (not spike sorted) on each channel, and (2) the total power in the band-pass filtered signal. Neural signals were decoded in real-time using (1) the Kalman filter, and (2) Gaussian process regression. 
Results:

Neural control was poor at the start of calibration for each participant; as more data were collected, each user gained better control in all directions. Towards the end of calibration, the time to target acquisition was comparable to state-of-the-art decoding and calibration methods. Decoder performance saturated within 3 minutes for each participant.
Conclusions:

These data suggest that intracortical brain computer interfaces can provide 2D cursor control with performance plateauing within 3 min of starting calibration. This study is an important step toward a neural prosthetic communication device that could be used by people with paralysis immediately upon deployment. 

Submission Type:

Oral

Name:

Joseph Buwembo

Abstract Title:

Direct Sciatic Nerve Electrical Stimulation (DISNES) for Complex Regional Pain Syndrome (CRPS) Type I

Authors:

Joseph Buwembo, Russell Munson

Affiliations:

Saskatchewan Health Authority

Abstract:

Introduction:
Foot and leg pain in CRPS has presents a challenge in management even with neuromodulation techniques such as spinal cord stimulation (SCS) and dorsal root ganglion (DRG) stimulation. We report our experience with a novo technique of Direct Sciatic Nerve Electrical Stimulation (DISNES) for intractable foot and leg pain in CRPS I.
Methods:
Thirteen patients (7 Females and 6 Males, age range is 31 – 62 years) were subjected to ipsilateral DISNES. All patients had failed conventional medical management (CMM) and 6 patients who were previously treated with SCS for CRPS I pain had relief of pain symptoms in the thigh and the leg but SCS was unable to alleviate the disabling foot pain. The remaining 7 patients were treated primarily with DISNES. Evaluation of the patients was done using Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), and Quality of Life (EQ-5D, and SF-36) Scores done both pre-DISNES and at two follow-ups post DISNES.
Results:
VAS Scores decreased by >50% at the first follow-up and a similar decrease in disability scores was seen in ODI. Quality of life indexes (SF-36 and EQ-5D) both showed improvement in all parameters following DISNES. There was also a rapid resolution of autonomic features such as edema, hyperemia, and allodynia (within 7-10 days). Two subjects returned to work post-DISNES.
Conclusion:
Our study shows that DISNES helps control the disabling foot pain in CRPS I patients, thus improving the quality of life, improving ambulation and decreasing disability. DISNES also alleviates autonomic features and dystonia in CRPS I. Further studies would be needed to determine long term efficacy of DISNES as this study pool is limited in size and follow up period.

Submission Type:

Oral

Name:

Jan Huizinga

Abstract Title:

Sacral Low-Level Laser Stimulation Triggers Autonomic Nerves Visible in a Change in Heart Rate Variability

Authors:

M. Khawar Ali, Shrayasee Saha, Ji-Hong Chen, Jan D. Huizinga

Affiliations:

McMaster University

Abstract:

Introduction and aim:

Our ultimate goal is to restore abnormal defecation reflexes mediated by Onuf’s nucleus and the sacral parasympathetic nucleus, through sacral low level laser therapy or photo-neuromodulation. Our first aim was to investigate if sacral subcutaneous low-level laser stimulation (LLLS) would penetrate the sacral area enough to stimulate autonomic nerves and to see if this could be measured by heart rate variability (HRV) since our hypothesis was that if action potentials were triggered they would go up to the NTS and likely affect HRV.

Methods:

Sacral nerves were stimulated in 16 patients with motility disorders, with LLLS using IR LED light at wavelength of 840 nm for 10 minutes and IR Laser light with wavelength of 825 nm for 20 minutes. Respiratory Sinus Arrhythmia (RSA) and SD1 (minor axis of Poincare plot) were used to quantify parasympathetic reactivity and Pre-Ejection Period (PEP) was used as a measure of sympathetic reactivity.
Results:

IR Laser light induced parasympathetic activity (RSA increased by 10.8%, P< 0.02, SD1 increased by 45%; P< 0.001) while there was no effect on PEP value hence no change in sympathetic activity.

Conclusion and inference:

LLLS activates sacral nerves; neural activity travels to the NTS and influences heart rate variability. This is a promising first step in evaluation of low-level laser therapy to restore autonomic neural reflexes associated with defecation.

Submission Type:

Poster/Oral

Name:

Yasmine Hoydonckx

Abstract Title:

Specific Neuropathic Pain Subgroups Detected By Validated Questionnaires Predict Response to Spinal Cord Stimulation

Authors:

Yasmine Hoydonckx, Pranab Kumar, Suneil Kalia, Mojgan Hodaie, Jamal Kara, Kawalpreet Singh Dhillon, Anuj Bhatia

Affiliations:

University of Toronto, Toronto Western Hospital

Abstract:

Introduction:

Spinal cord stimulation (SCS) is used to treat neuropathic pain (NP) from a variety of etiologies. There is a lack of data on specific NP symptoms that are more likely to abate with SCS. This retrospective study evaluated specific phenotypes of NP that were associated with success of SCS trial.
Methods:

Data from SCS patients who had trialed at our centre between July 1, 2017 to November 30, 2018 was accessed from our database after approval from the Institutional REB. SCS trials at our centre involve use of tonic stimulation for 4 days followed by 4 days of paresthesia-free stimulation. A minimum of 50% reduction in pain intensity from baseline is required with either or both SCS modes to classify the trial as “success”. Data from two validated questionnaires for NP was also accessed – Douleur Neuropathique 4 (DN4; a screening questionnaire) and Neuropathic Pain Symptom Inventory (NPSI; a questionnaire designed to evaluate the different symptoms of NP over time).
Results:

64 patients underwent SCS trials with a success rate of 66%. Patients with a successful trial had significantly lower mean DN4 and NPSI scores at the end of the trial compared to baseline. Patients who had a successful trial had a significant reduction in NPSI scores for superficial spontaneous burning, deep spontaneous pressure, paroxysmal, and paresthesia/dysesthesia subscales compared to those who failed. Further, patients who failed the trial were seen to have only reduction of the superficial spontaneous burning and paresthesia/dysesthesia subscales of NPSI.
Conclusions:

Incorporating validated tools to evaluate subgroups of NP can help in improving success rate of SCS trials. Further research and evaluation of long-term outcomes are required to compare effects of tonic and paresthesia-free SCS modes on different phenotypes of NP.

Submission Type:

Poster/Oral