Awake Craniotomy without Invasive Blood Pressure Monitoring.

OBJECTIVE: To assess the safety of foregoing invasive monitoring in a select group of patients undergoing awake craniotomy for supratentorial tumor resection. METHODS: Awake craniotomies were performed for tumor resection without invasive blood pressure monitoring when there was no preexisting cardiopulmonary indication as determined by the attending anesthesiologist according to institutional protocol. Noninvasive monitoring was performed every 3-5 minutes intraoperatively and then every 15 minutes in the recovery room for 4 hours before transfer to the ward. RESULTS: At a single tertiary care hospital, 74 consecutive awake surgeries were performed with noninvasive blood pressure monitoring. Among patients, 39 (52.7%) were male, 42 (83.8%) had infiltrative primary brain tumors, 2 (2.7%) had a history of coronary artery disease, 6 (8.1%) were diabetics, 10 (29.7%) were smokers, and 22 (29.7%) were on antihypertensive medications preoperatively. American Society of Anesthesiologists classification was I in 1.4% of patients, II in 36.4%, III in 60.8%, and IV in 1.4%. Intraoperative vasoactive medications were administered in 21 (28.4%) patients; 8 (38%) of these were on antihypertensive agents preoperatively. Vasodilators were administered in 13 (61.9%) patients, vasopressors were given in 6 (28.6%) patients, and both vasodilators and vasopressors were given in 2 (9.5%) patients. One patient experienced a lenticulostriate artery stroke intraoperatively, and 1 patient experienced atrial fibrillation 1 week postoperatively. There were no other perioperative anesthetic, hemorrhagic, renal, or cardiopulmonary complications. CONCLUSIONS: Intraoperative physiologic control and surgical site complication avoidance do not warrant routine invasive blood pressure monitoring during awake craniotomy for tumor resection.

Does tamsulosin decrease postoperative urinary retention in spine surgery? A double-blind, randomized controlled trial.

OBJECTIVE: The authors' objective was to determine whether preoperative administration of tamsulosin decreases postoperative urinary retention after spine surgery. METHODS: In this randomized, double-blind, placebo-controlled clinical trial performed at a single institution between 2016 and 2019, eligible males aged 50 to 85 years were administered tamsulosin or placebo for 5 days prior to elective spine surgery. Patients were excluded if they were taking alpha adrenergic blocking drugs; were allergic to tamsulosin, lactose, or sulfa drugs; had a preexisting indwelling urinary catheter, orthostatic hypotension, history of urological surgery, or renal failure; or were scheduled for cataract surgery within 2 weeks. Screening identified 1051 eligible patients (140 declined participation, 150 did not meet the inclusion criteria, and 151 did not enroll for other reasons). A total of 610 patients were randomly assigned to receive 0.4 mg oral tamsulosin or an identical placebo capsule for 5 days preoperatively and 2 days postoperatively. RESULTS: A total of 497 patients were included in the final statistical analysis. The overall rate of postoperative urinary retention was 9.7%, and tamsulosin had no observed effect on reducing the rate of postoperative urinary retention as compared with placebo (9.4% vs 9.9%, p = 0.96). There were no significant differences in the reported adverse events between groups. Multivariate logistic regression was performed to model the effects of patient, surgical, and anesthetic factors on postoperative urinary retention, and the study drug remained an insignificant factor. CONCLUSIONS: This study did not detect an effect of perioperative tamsulosin on reducing the rate of postoperative urinary retention in male patients aged 50 to 85 years who underwent elective spine surgery. This study does not support the routine use of tamsulosin to reduce postoperative urinary retention in patients without a previous prescription. It is unknown if subpopulations exist for which prophylactic tamsulosin may reduce postoperative urinary retention.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline on Subthalamic Nucleus and Globus Pallidus Internus Deep Brain Stimulation for the Treatment of Patients With Parkinson's Disease: Executive Summary.

QUESTION 1: Is bilateral subthalamic nucleus deep brain stimulation (STN DBS) more, less, or as effective as bilateral globus pallidus internus deep brain stimulation (GPi DBS) in treating motor symptoms of Parkinson's disease, as measured by improvements in Unified Parkinson's Disease Rating Scale, part III (UPDRS-III) scores? RECOMMENDATION: Given that bilateral STN DBS is at least as effective as bilateral GPi DBS in treating motor symptoms of Parkinson's disease (as measured by improvements in UPDRS-III scores), consideration can be given to the selection of either target in patients undergoing surgery to treat motor symptoms. (Level I). QUESTION 2: Is bilateral STN DBS more, less, or as effective as bilateral GPi DBS in allowing reduction of dopaminergic medication in Parkinson's disease? RECOMMENDATION: When the main goal of surgery is reduction of dopaminergic medications in a patient with Parkinson's disease, then bilateral STN DBS should be performed instead of GPi DBS. (Level I). QUESTION 3: Is bilateral STN DBS more, less, or as effective as bilateral GPi DBS in treating dyskinesias associated with Parkinson's disease? RECOMMENDATION: There is insufficient evidence to make a generalizable recommendation regarding the target selection for reduction of dyskinesias. However, when the reduction of medication is not anticipated and there is a goal to reduce the severity of "on" medication dyskinesias, the GPi should be targeted. (Level I). QUESTION 4: Is bilateral STN DBS more, less, or as effective as bilateral GPi DBS in improving quality of life measures in Parkinson's disease? RECOMMENDATION: When considering improvements in quality of life in a patient undergoing DBS for Parkinson's disease, there is no basis to recommend bilateral DBS in 1 target over the other. (Level I). QUESTION 5: Is bilateral STN DBS associated with greater, lesser, or a similar impact on neurocognitive function than bilateral GPi DBS in Parkinson disease? RECOMMENDATION: If there is significant concern about cognitive decline, particularly in regards to processing speed and working memory in a patient undergoing DBS, then the clinician should consider using GPi DBS rather than STN DBS, while taking into consideration other goals of surgery. (Level I). QUESTION 6: Is bilateral STN DBS associated with a higher, lower, or similar risk of mood disturbance than GPi DBS in Parkinson's disease? RECOMMENDATION: If there is significant concern about the risk of depression in a patient undergoing DBS, then the clinician should consider using pallidal rather than STN stimulation, while taking into consideration other goals of surgery. (Level I). QUESTION 7: Is bilateral STN DBS associated with a higher, lower, or similar risk of adverse events compared to GPi DBS in Parkinson's disease? RECOMMENDATION: There is insufficient evidence to recommend bilateral DBS in 1 target over the other in order to minimize the risk of surgical adverse events. The full guideline can be found at: https://www.cns.org/guidelines/deep-brain-stimulation-parkinsons-disease.

Socioeconomic and regional differences in the treatment of cervical spondylotic myelopathy.

BACKGROUND: Cervical spondylotic myelopathy (CSM) is the leading cause of spinal cord dysfunction in the world. Surgical treatment is both medically and economically advantageous, and can be achieved through multiple approaches, with or without fusion. We used the Nationwide Inpatient Sample (NIS) database to better elucidate regional and socioeconomic variances in the treatment of CSM. METHODS: The NIS database was queried for elective admissions with a primary diagnosis of CSM (ICD-9 721.1). This was evaluated for patients who also carried a diagnosis of anterior (ICD-9 81.02) or posterior cervical fusion (ICD-9 81.03), posterior cervical laminectomy (ICD 03.09), or a combination. We then investigated variances including regional trends and disparities according to hospital and insurance types. RESULTS: During 2002-2012, 50605 patients were electively admitted with a diagnosis of CSM. Anterior fusions were more common in Midwestern states and in nonteaching hospitals. Fusion procedures were used more frequently than other treatments in private hospitals and with private insurance. Median hospital charges were also expectedly higher for fusion procedures and combined surgical approaches. Combined approaches were found to be significantly greater in patients with concurrent diagnoses of ossification of the posterior longitudinal ligament (OPLL) and CSM. Ultimately, there has been an increased utilization of fusion procedures versus nonfusion treatments, over the past decade, for patients with cervical myelopathy. CONCLUSIONS: Fusion surgery is being increasingly used for the treatment of CSM. Expensive procedures are being performed more frequently in both private hospitals and for those with private insurance, whereas the most economical procedure, posterior cervical laminectomy, was underutilized.

A protocol for postoperative admission of elective craniotomy patients to a non-ICU or step-down setting.

OBJECTIVE Selecting the appropriate patients undergoing craniotomy who can safely forgo postoperative intensive care unit (ICU) monitoring remains a source of debate. Through a multidisciplinary work group, the authors redefined their institutional care process for postoperative monitoring of patients undergoing elective craniotomy to include transfer from the postanesthesia care unit (PACU) to the neurosurgical floor. The hypothesis was that an appropriately selected group of patients undergoing craniotomy could be safely managed outside the ICU in the postoperative period. METHODS The work group developed and implemented a protocol for transfer of patients to the neurosurgical floor after 4-hour recovery in the PACU following elective craniotomy for supratentorial tumor. Criteria included hemodynamically stable adults without significant new postoperative neurological impairment. Data were prospectively collected including patient demographics, clinical characteristics, surgical details, postoperative complications, and events surrounding transfer to a higher level of care. RESULTS Of the first 200 consecutive patients admitted to the floor, 5 underwent escalation of care in the first 48 hours. Three of these escalations were for agitation, 1 for seizure, and 1 for neurological change. Ninety-eight percent of patients meeting criteria for transfer to the floor were managed without incident. No patient experienced a major complication or any permanent morbidity or mortality following this care pathway. CONCLUSIONS Care of patients undergoing uneventful elective supratentorial craniotomy for tumor on a neurosurgical floor after 4 hours of PACU monitoring appears to be a safe practice in this patient population. This tailored practice safely optimized hospital resources, is financially responsible, and is a strong tool for improving health care value.

Increased Utilization of Cervical Disk Arthroplasty in University Hospitals with Regional Variation and Socioeconomic Discrepancies.

OBJECTIVE: Treatment of cervical radiculopathy with disk arthroplasty has been approved by the U.S. Food and Drug Administration since 2007. Recently, a significant increase in clinical data including mid- and long-term follow-up has become available, demonstrating the superiority of disk arthroplasty compared with anterior discectomy and fusion. The aim of this project is to assess the nationwide use of cervical disk arthroplasty. METHODS: The University Healthcare Consortium database was accessed for all elective cases of patients treated for cervical radiculopathy caused by disk herniation (International Classification of Diseases [ICD] 722.0) from the fourth quarter of 2012 to the third quarter of 2015. Within this 3-year window, temporal and socioeconomic trends in the use of cervical disk replacement for this diagnosis were assessed. RESULTS: Three thousand four hundred forty-six cases were identified. A minority of cases (10.7%) were treated with disk arthroplasty. Median hospital charges were comparable for cervical disk replacement ($15,606) and anterior cervical fusion ($15,080). However, utilization was seen to increase by nearly 70% during the timeframe assessed. Disk arthroplasty was performed in 8% of patients in 2012 to 2013, compared with 13% of cases in 2015. Disk replacement use was more common for self-paying patients, patients with private insurance, and patients with military-based insurance. There was widespread variation in the use of cervical disk replacement between regions, with a nadir in northeastern states (8%) and a peak in western states (20%). CONCLUSION: Over a short, 3 -year period there has been an increase in the treatment of symptomatic cervical radiculopathy with disk arthroplasty. The authors predict a further increase in cervical disk arthroplasty in upcoming years.

Pedunculopontine Nucleus Region Deep Brain Stimulation in Parkinson Disease: Surgical Techniques, Side Effects, and Postoperative Imaging.

The pedunculopontine nucleus (PPN) region has received considerable attention in clinical studies as a target for deep brain stimulation (DBS) in Parkinson disease. These studies have yielded variable results with an overall impression of improvement in falls and freezing in many but not all patients treated. We evaluated the available data on the surgical anatomy and terminology of the PPN region in a companion paper. Here we focus on issues concerning surgical technique, imaging, and early side effects of surgery. The aim of this paper was to gain more insight into the reasoning for choosing specific techniques and to discuss shortcomings of available studies. Our data demonstrate the wide range in almost all fields which were investigated. There are a number of important challenges to be resolved, such as identification of the optimal target, the choice of the surgical approach to optimize electrode placement, the impact on the outcome of specific surgical techniques, the reliability of intraoperative confirmation of the target, and methodological differences in postoperative validation of the electrode position. There is considerable variability both within and across groups, the overall experience with PPN DBS is still limited, and there is a lack of controlled trials. Despite these challenges, the procedure seems to provide benefit to selected patients and appears to be relatively safe. One important limitation in comparing studies from different centers and analyzing outcomes is the great variability in targeting and surgical techniques, as shown in our paper. The challenges we identified will be of relevance when designing future studies to better address several controversial issues. We hope that the data we accumulated may facilitate the development of surgical protocols for PPN DBS.

Pedunculopontine Nucleus Region Deep Brain Stimulation in Parkinson Disease: Surgical Anatomy and Terminology.

Several lines of evidence over the last few years have been important in ascertaining that the pedunculopontine nucleus (PPN) region could be considered as a potential target for deep brain stimulation (DBS) to treat freezing and other problems as part of a spectrum of gait disorders in Parkinson disease and other akinetic movement disorders. Since the introduction of PPN DBS, a variety of clinical studies have been published. Most indicate improvements in freezing and falls in patients who are severely affected by these problems. The results across patients, however, have been variable, perhaps reflecting patient selection, heterogeneity in target selection and differences in surgical methodology and stimulation settings. Here we outline both the accumulated knowledge and the domains of uncertainty in surgical anatomy and terminology. Specific topics were assigned to groups of experts, and this work was accumulated and reviewed by the executive committee of the working group. Areas of disagreement were discussed and modified accordingly until a consensus could be reached. We demonstrate that both the anatomy and the functional role of the PPN region need further study. The borders of the PPN and of adjacent nuclei differ when different brainstem atlases and atlas slices are compared. It is difficult to delineate precisely the PPN pars dissipata from the nucleus cuneiformis, as these structures partially overlap. This lack of clarity contributes to the difficulty in targeting and determining the exact localization of the electrodes implanted in patients with akinetic gait disorders. Future clinical studies need to consider these issues.

Appraisal of the Quality of Neurosurgery Clinical Practice Guidelines.

OBJECTIVE: The rate of neurosurgery guidelines publications was compared over time with all other specialties. Neurosurgical guidelines and quality of supporting evidence were then analyzed and compared by subspecialty. METHODS: The authors first performed a PubMed search for "Neurosurgery" and "Guidelines." This was then compared against searches performed for each specialty of the American Board of Medical Specialties. The second analysis was an inventory of all neurosurgery guidelines published by the Agency for Healthcare Research and Quality Guidelines clearinghouse. All Class I evidence and Level 1 recommendations were compared for different subspecialty topics. RESULTS: When examined from 1970-2010, the rate of increase in publication of neurosurgery guidelines was about one third of all specialties combined (P < 0.0001). However, when only looking at the past 5 years the publication rate of neurosurgery guidelines has converged upon that for all specialties. The second analysis identified 49 published guidelines for assessment. There were 2733 studies cited as supporting evidence, with only 243 of these papers considered the highest class of evidence (8.9%). These papers were used to generate 697 recommendations, of which 170 (24.4%) were considered "Level 1" recommendations. CONCLUSION: Although initially lagging, the publication of neurosurgical guidelines has recently increased at a rate comparable with that of other specialties. However, the quality of the evidence cited consists of a relatively low number of high-quality studies from which guidelines are created. Wider implications of this must be considered when defining and measuring quality of clinical performance in neurosurgery.

Survival following Ommaya reservoir placement for neoplastic meningitis.

The objective of this study was to evaluate the outcomes of patients with neoplastic meningitis (NM) following Ommaya reservoir placement in order to determine whether any patient factors are associated with longer survival. NM is a devastating late manifestation of cancer, and given its dismal prognosis, identifying appropriate patients for Ommaya reservoir placement is difficult. The authors performed a retrospective review of 80 patients who underwent Ommaya reservoir placement at three medical centers from September 2001 through September 2012. The primary outcome was death. Differences in survival were assessed with Kaplan-Meier survival analyses. The Cox proportional hazards and logistic regression modeling were performed to identify factors associated with survival. The primary diagnoses were solid organ, hematologic, and primary central nervous system tumors in 53.8%, 41.3%, and 5%, respectively. The median overall survival was 72.5 days (95% confidence interval 36-122) with 30% expiring within 30 days and only 13.8% surviving more than 1 year. There were no differences in median overall survival between sites (p=0.37) despite differences in time from diagnosis of NM to Ommaya reservoir placement (p<0.001). Diagnosis of hematologic malignancy was inversely associated with death within 90 days (p=0.04; odds ratio 0.34), older age was associated with death within 90 days (p=0.05; odds ratio 1.5, per 10 year increase in age). The prognosis of NM remains poor despite the available treatment with intraventricular chemotherapy. There exists significant variability in treatment algorithms among medical centers and consideration of this variability is crucial when interpreting existing series of Ommaya reservoir use in the treatment of patients with NM.

A socioeconomic analysis of intraoperative neurophysiological monitoring during spine surgery: national use, regional variation, and patient outcomes.

OBJECT: In the United States in recent years, a dramatic increase in the use of intraoperative neurophysiological monitoring (IONM) during spine surgeries has been suspected. Myriad reasons have been proposed, but no clear evidence confirming this trend has been available. In this study, the authors investigated the use of IONM during spine surgery, identified patterns of geographic variation, and analyzed the value of IONM for spine surgery cases. METHODS: In this retrospective analysis, the Nationwide Inpatient Sample was queried for all spine surgeries performed during 2007-2011. Use of IONM (International Classification of Diseases, Ninth Revision, code 00.94) was compared over time and between geographic regions, and its effect on patient independence at discharge and iatrogenic nerve injury was assessed. RESULTS: A total of 443,194 spine procedures were identified, of which 85% were elective and 15% were not elective. Use of IONM was recorded for 31,680 cases and increased each calendar year from 1% of all cases in 2007 to 12% of all cases in 2011. Regional use of IONM ranged widely, from 8% of cases in the Northeast to 21% of cases in the West in 2011. Iatrogenic nerve and spinal cord injury were rare; they occurred in less than 1% of patients and did not significantly decrease when IONM was used. CONCLUSIONS: As costs of spine surgeries continue to rise, it becomes necessary to examine and justify use of different medical technologies, including IONM, during spine surgery.

Deep brain stimulation for obsessive-compulsive disorder: systematic review and evidence-based guideline sponsored by the American Society for Stereotactic and Functional Neurosurgery and the Congress of Neurological Surgeons (CNS) and endorsed by the CNS and American Association of Neurological Surgeons.

BACKGROUND: It is estimated that 40% to 60% of patients with obsessive-compulsive disorder (OCD) continue to experience symptoms despite adequate medical management. For this population of treatment-refractory patients, promising results have been reported with the use of deep brain stimulation (DBS). OBJECTIVE: To conduct a systematic review of the literature and develop evidence-based guidelines on DBS for OCD. METHODS: A systematic literature search was undertaken using the PubMed database for articles published between 1966 and October 2012 combining the following words: "deep brain stimulation and obsessive-compulsive disorder" or "electrical stimulation and obsessive-compulsive disorder." Of 353 articles, 7 were retrieved for full-text review and analysis. The quality of the articles was assigned to each study and the strength of recommendation graded according to the guidelines development methodology of the American Association of Neurological Surgeons/Congress of Neurological Surgeons Joint Guidelines Committee. RESULTS: Of the 7 studies, 1 class I and 2 class II double-blind, randomized, controlled trials reported that bilateral DBS is more effective in improving OCD symptoms than sham treatment. CONCLUSION: Based on the data published in the literature, the following recommendations can be made: (1) There is Level I evidence, based on a single class I study, for the use of bilateral subthalamic nucleus DBS for the treatment of medically refractory OCD. (2) There is Level II evidence, based on a single class II study, for the use of bilateral nucleus accumbens DBS for the treatment of medically refractory OCD. (3) There is insufficient evidence to make a recommendation for the use of unilateral DBS for the treatment of medically refractory OCD.

Bilateral pallidal stimulation for sargoglycan epsilon negative myoclonus.

We report on the clinical efficacy of bilateral globus pallidus internus deep brain stimulation in two patients with myoclonus dystonia/essential myoclonus who lack mutations in the epsilon sarcoglycan gene. The primary outcome measures were the Burke-Fahn-Marsden Dystonia Scale motor severity and the Unified Myoclonus Rating Scale scores, and the secondary outcome measure was the 36-item Short Form Health Survey score at the last postoperative follow up. Neuronal firing rates were also calculated from microelectrode recordings. At the last postoperative follow-up (16 weeks for Patient 1 and 18 weeks for Patient 2), there was 57.1% (Patient 1) improvement in the Burke-Fahn-Marsden Dystonia Scale motor severity score and 31.3% (Patient 1) and 69% (Patient 2) in the Unified Myoclonus Rating Scale score while individual SF-36 scores showed improvement in most subdomains. Bilateral globus pallidus internus deep brain stimulation can be effective in ameliorating epsilon sarcoglycan negative myoclonus with or without concurrent dystonia. Whether an epsilon sarcoglycan negative status represents a less favorable prognostic factor for pallidal deep brain stimulation remains to be elucidated.

Acute complications of movement disorders surgery: effects of age and comorbidities.

The most common indication for movement disorder surgery is Parkinson's disease (PD), and the incidence of PD increases with age. The analysis reported here was undertaken with the primary goal of examining whether there is a relationship between peri-operative complications and age. The Nationwide Inpatient Sample (Agency for Healthcare Research and Quality, Rockville, MD, USA) was queried for 10 years beginning in 1999 for patients undergoing deep brain stimulator insertion, pallidotomy, and thalamotomy for treatment of PD, essential tremor, and dystonia. Inpatient complications, including death, stroke (both ischemic and hemorrhagic), and other overall complications were examined. The relative risks associated with advanced age; primary diagnosis; treatment modality; the diagnoses of hypertension, diabetes, and nicotinism; and the cumulative number of comorbidities were examined. There were 5464 patients who met inclusion criteria, including 4145 patients treated for PD and 4961 patients treated with deep brain stimulation (DBS). Overall in-hospital mortality was 0.26%, with 0.15% related to surgical factors. There was a correlation between in-hospital mortality, increasing age, and number of medical comorbidities. After multivariate regression no factor remained predictive of mortality. Having more than 1 medical comorbidity or PD increased the risk of in-hospital complications. Patients with PD were more likely to suffer hemorrhage or stroke. Hypertension, diabetes, nicotinism, and modality of treatment were not associated with increased mortality, hemorrhage or stroke risk, or in-hospital mortality in univariate or multivariate analysis. Both age and medical comorbidity are correlated with in-hospital complications, but age appears to serve as a surrogate for comorbidity. Surgery for PD appears to carry an increased risk of hemorrhage or stroke and in-hospital complications.

Bilateral pallidal stimulation for Wilson's disease.

BACKGROUND: To report on the clinical efficacy of bilateral globus pallidus internus deep brain stimulation in a 29-year-old patient with severe generalized dystonia secondary to Wilson's disease. METHODS: The primary outcome measure was the Burke-Fahn-Marsden Dystonia Scale motor severity score (blinded assessment) and the secondary outcome measures were the Abnormal Involuntary Movement Scale (blinded assessment) and the Zaritt Caregiver Burden Interview score, at 20-week postoperative follow up. RESULTS: There was a 14% improvement in the Burke-Fahn-Marsden Dystonia Scale motor severity score. Abnormal Involuntary Movement Scale score remained unchanged while the Zaritt Caregiver Burden Interview score improved by 44.4%. CONCLUSIONS: Bilateral globus pallidus deep brain stimulation can be effective in ameliorating dystonia and caregiver burden in Wilson's disease. Outcomes may depend on the stage of the disease at which the surgical procedure is completed. © 2013 Movement Disorder Society.

Lower motor neuron findings after upper motor neuron injury: insights from postoperative supplementary motor area syndrome.

Hypertonia and hyperreflexia are classically described responses to upper motor neuron injury. However, acute hypotonia and areflexia with motor deficit are hallmark findings after many central nervous system insults such as acute stroke and spinal shock. Historic theories to explain these contradictory findings have implicated a number of potential mechanisms mostly relying on the loss of descending corticospinal input as the underlying etiology. Unfortunately, these simple descriptions consistently fail to adequately explain the pathophysiology and connectivity leading to acute hyporeflexia and delayed hyperreflexia that result from such insult. This article highlights the common observation of acute hyporeflexia after central nervous system insults and explores the underlying anatomy and physiology. Further, evidence for the underlying connectivity is presented and implicates the dominant role of supraspinal inhibitory influence originating in the supplementary motor area descending through the corticospinal tracts. Unlike traditional explanations, this theory more adequately explains the findings of postoperative supplementary motor area syndrome in which hyporeflexia motor deficit is observed acutely in the face of intact primary motor cortex connections to the spinal cord. Further, the proposed connectivity can be generalized to help explain other insults including stroke, atonic seizures, and spinal shock.