Spinal Cord Stimulators: an Introduction

Pain can be divided into two broad categories, nociceptive pain and neuropathic pain. Nociceptive pain is a dull, throbbing pain which results from irritated nerves after physical tissue injury. This is seen commonly in cancer or after a fracture. Nociceptive pain is amenable to treatment with pain medications such as opioids and/or anti-inflammatories. Neuropathic pain is described as burning, shooting, or shocking pain. This type of pain results from nerve damage or abnormal nerve conduction such as pain exhibited with failed back syndrome, post surgical pain, neuromas, shingles, and complex regional pain syndrome (previously called RSD or causalgia). Neuropathic pain tends to be resistant to treatment with pain medications. Neurostimulation has been an effective treatment option for the management of chronic neuropathic pain. It is a reversible therapy which can even be tested before permanent implantation. Spinal cord stimulation (SCS) is an adjustable, non-destructive, neuromodulatory procedure which delivers therapeutic doses of electrical current to the spinal cord or to a targeted nerve. This low-voltage stimulation can block the transmission of pain. The enthusiasm for SCS began with the introduction of the gate control theory for pain control by Melzack and Wall in 1965 1.They noted that stimulation of large myelinated fibers of peripheral nerves resulted in paresthesias and blocked the activity in small nociceptive projections. In other words, pain receptors compete with each other and with other sensory afferents. Appropriate stimulation of a “rival” afferent can effectively block a pain signal. This is why rubbing your chin after its been hit relieves the pain – the bump is still present, but the rubbing blocks it. The SCS system is implanted in a space surrounding the spinal cord, called the epidural space, where it stimulates the dorsal columns which can mask the sensation of pain by producing a tingling sensation

Case Report: Intramedullary Cervical Spinal Cord Hemangioblastoma with an Evaluation of von Hippel-Lindau Disease

History of Present Illness MO is a 49 year old male with a history of multiple sclerosis who presents with a one year history of progressive numbness in his shoulders bilateral and upper back. The patient describes occasional sharp pains that radiate to his first three fingers on his right hand. He denies weakness, clumsiness, difficulty walking, or bladder/bowel dysfunction. He describes no problems with handwriting, or fine motor skills

Awake vs. Asleep Placement of Spinal Cord Stimulators: A Cohort Analysis of Complications Associated With Placement

Introduction: Patients will typically undergo awake surgery for permanent implantation of SCS in an attempt to optimize electrode placement using patient feedback about the distribution of stimulation-induced paresthesia. The present study compared efficacy of first-time electrode placement under awake conditions with that of neurophysiologically-guided placement under general anesthesia. Methods: A retrospective review was performed of 387 SCS surgeries among 259 patients which included 167 new stimulator implantation to determine whether first time awake surgery for placement of spinal cord stimulators is preferable to non-awake placement. Results: The incidence of device failure for patients implanted using neurophysiologically-guided placement under general anesthesia was one-half that for patients implanted awake (14.94% vs 29.7%). Conclusion: Non-awake surgery is associated with fewer failure rates and therefore fewer re-operations, making it a viable alternative. Any benefits of awake implantation should carefully be considered in the future

Development of an Educational Curriculum for Spinal Cord Stimulation.

BACKGROUND: Spinal cord stimulators (SCSs) are used for treating chronic pain. The number of SCSs implanted each year is on the increase. The North American Neuromodulation Society (NANS) education committee aimed to develop a SCS curriculum as a tool to guide physicians at different training levels, based on the most recent evidence. MATERIAL AND METHODS: A multidisciplinary (anesthesiology, physical medicine, neurosurgery, and neurology), taskforce representing the education committee of the NANS met to develop a SCS curriculum following the Accreditation Council for Graduate Medical Education (ACGME) milestones. The task force used the best available evidence and knowledge to develop the curriculum. Once developed, the SCS curriculum was then approved by the NANS board. RESULTS: The task force developed a SCS training curriculum. Milestones included patient care and procedural skills, system-based practice, medical knowledge, interpersonal communication, practice based learning and professionalism. Each milestone was defined for three categories, early learner, advanced learner, and practitioner. CONCLUSION: A multidisciplinary task force of the NANS education committee developed a SCS training curriculum that defines ACGME milestones for basic learners, advanced learners, and practitioners

Prognostication of traumatic brain injury outcomes in older trauma patients: A novel risk assessment tool based on initial cranial CT findings.

INTRODUCTION: Advanced age has been traditionally associated with worse traumatic brain injury (TBI) outcomes. Although prompt neurosurgical intervention (NSI, craniotomy or craniectomy) may be life-saving in the older trauma patient, it does not guarantee survival and/or return to preinjury functional status. The aim of this study was to determine whether a simple score, based entirely on the initial cranial computed tomography (CCT) is predictive of the need for NSI and key outcome measures (e.g., morbidity and mortality) in the older (age 45+ years) TBI patient subset. We hypothesized that increasing number of categorical CCT findings is independently associated with NSI, morbidity, and mortality in older patients with severe TBI. METHODS: After IRB approval, a retrospective study of patients 45 years and older was performed using our Regional Level 1 Trauma Center registry data between June 2003 and December 2013. Collected variables included patient demographics, Injury Severity Score (ISS), Abbreviated Injury Scale Head (AISh), brain injury characteristics on CCT, Glasgow Coma Scale (GCS), Intensive Care Unit (ICU) and hospital length of stay (LOS), all-cause morbidity and mortality, functional independence scores, as well as discharge disposition. A novel CCT scoring tool (CCTST, scored from 1 to 8+) was devised, with one point given for each of the following findings: subdural hematoma, epidural hematoma, subarachnoid blood, intraventricular blood, cerebral contusion/intraparenchymal blood, skull fracture, pneumocephalus, brain edema/herniation, midline shift, and external (skin/face) trauma. Descriptive statistics and univariate analyses were conducted with 30-day mortality, in-hospital morbidity, and need for NSI as primary end-points. Secondary end-points included the length of stay in the ICU (ICULOS), step-down unit (SDLOS), and the hospital (HLOS) as well as patient functional outcomes, and postdischarge destination. Factors associated with the need for NSI were determined using matched NSI ( RESULTS: A total of 620 patients were analyzed, including 310 patients who underwent NSI and 310 age- and ISS-matched non-NSI controls. Average patient age was 72.8 ± 13.4 years (64.1% male, 99% blunt trauma, mean ISS 25.1 ± 8.68, and mean AISh/GCS of 4.63/10.9). CCTST was the only variable independently associated with NSI (AOR 1.23, 95% CI 1.06-1.42) and was inversely proportional to initial GCS and functional outcome scores on discharge. Increasing CCTST was associated with greater mortality, morbidity, HLOS, SDLOS, ICULOS, and ventilator days. On multivariate analysis, factors independently associated with mortality included AISh (AOR 2.70, 95% CI 1.21-6.00), initial GCS (AOR 1.14, 1.07-1.22), and CCTST (AOR 1.31, 1.09-1.58). Variables independently associated with in-hospital morbidity included CCTST (AOR 1.16, 1.02-1.34), GCS (AOR 1.05, 1.01-1.09), and NSI (AOR 2.62, 1.69-4.06). Multivariate models incorporating factors independently associated with each respective outcome displayed good overall predictive characteristics for mortality (AUC 0.787) and in-hospital morbidity (AUC 0.651). Finally, modified CCTST demonstrated good overall predictive ability for NSI (AUC 0.755). CONCLUSION: This study found that the number of discrete findings on CCT is independently associated with major TBI outcome measures, including 30-day mortality, in-hospital morbidity, and NSI. Of note, multivariate models with best predictive characteristics incorporate both CCTST and GCS. CCTST is easy to calculate, and this preliminary investigation of its predictive utility in older patients with TBI warrants further validation, focusing on exploring prognostic synergies between CCTST, GCS, and AISh. If independently confirmed to be predictive of clinical outcomes and the need for NSI, the approach described herein could lead to a shift in both operative and nonoperative management of patients with TBI