Restoration of sensory feedback from the foot and reduction of phantom limb pain via closed-loop spinal cord stimulation.

Restoring somatosensory feedback in individuals with lower-limb amputations would reduce the risk of falls and alleviate phantom limb pain. Here we show, in three individuals with transtibial amputation (one traumatic and two owing to diabetic peripheral neuropathy), that sensations from the missing foot, with control over their location and intensity, can be evoked via lateral lumbosacral spinal cord stimulation with commercially available electrodes and by modulating the intensity of stimulation in real time on the basis of signals from a wireless pressure-sensitive shoe insole. The restored somatosensation via closed-loop stimulation improved balance control (with a 19-point improvement in the composite score of the Sensory Organization Test in one individual) and gait stability (with a 5-point improvement in the Functional Gait Assessment in one individual). And over the implantation period of the stimulation leads, the three individuals experienced a clinically meaningful decrease in phantom limb pain (with an average reduction of nearly 70% on a visual analogue scale). Our findings support the further clinical assessment of lower-limb neuroprostheses providing somatosensory feedback.

Evaluation of free-hand screw placement in cervical, thoracic, and lumbar spine by neurosurgical residents.

BACKGROUND: Knowledge of free-hand screw technique remains critical to adequately train neurosurgical residents. The purpose of this study was to evaluate the accuracy of screw placement via the free-hand technique in lumbar, thoracic, and cervical spine by neurosurgical residents completing an enfolded spine fellowship. METHODS: Medical records of all patients who underwent free-hand screw placement at all spinal levels over a 6-month period by senior neurosurgical residents enrolled in an in-folded spine fellowship were retrospectively reviewed. Postoperative CT images were assessed for presence and direction of cortical breach. RESULTS: Twenty-six patients underwent 162 free-hand screw placements. The most commonly placed screws were cervical lateral mass screws (n = 69), thoracic (n = 41), and lumbar pedicle screws (n = 41). The most common indication for surgery was deformity (n = 22), followed by infection (n = 2) and trauma (n = 2). Fifty-five breaches were identified in 44 (27 %) screws placed in 21 patients (81 %). Anterior breach was identified in 22 cases (40.0 %), lateral in 12 (23.6 %), superior in 7 (12.7 %), and inferior in 7 (12.7 %), and medial in 6 (10.9 %). The most common level of breach was observed in cervical lateral mass screws (n = 19, 43 %) and least common in C2 pars screws (n = 1, 2%). With an average length of follow up of 12.1 ± 7.7 months of follow-up, no clinical sequalae of screw breach was observed. CONCLUSIONS: Despite the high prevalence of screw breach using the free-hand technique by neurosurgical residents, the absence of clinical sequelae implies safety and emphasizes the importance of early exposure to this technique during neurosurgical residency training.

Impact of Coronavirus Disease 2019 Shutdown on Neurotrauma Volume in Pennsylvania.

OBJECTIVE: The 2020 coronavirus disease 2019 (COVID-19) pandemic resulted in state-specific quarantine protocols and introduced the concept of social distancing into modern parlance. We assess the impact of the COVID-19 pandemic on neurotrauma presentations in the first 3 months after shutdown throughout Pennsylvania. METHODS: The Pennsylvania Trauma Systems Foundation was queried for registry data from the Pennsylvania Trauma Outcomes Study between March 12 and June 5 in each year from 2017 to 2020. RESULTS: After the COVID-19 shutdown, there was a 27% reduction in neurotrauma volume, from 2680 cases in 2017 to 2018 cases in 2020, and a 28.8% reduction in traumatic brain injury volume. There was no significant difference in neurotrauma phenotype incurred relative to total cases. Injury mechanism was less likely to be motor vehicle collision and more likely caused by falls, gunshot wound, and recreational vehicle accidents (P < 0.05). Location of injury was less likely on roads and public locations and more likely at indoor private locations (P < 0.05). The proportion of patients with neurotrauma with blood alcohol concentration >0.08 g/dL was reduced in 2020 (11.4% vs. 9.0%; P < 0.05). Mortality was higher during 2020 compared with pre-COVID years (7.7% vs. 6.4%; P < 0.05). CONCLUSIONS: During statewide shutdown, neurotrauma volume and alcohol-related trauma decreased and low-impact traumas and gunshot wounds increased, with a shift toward injuries occurring in private, indoor locations. These changes increased mortality. However, there was not a change in the types of injuries sustained.

Sport-Related Structural Brain Injury and Return to Play: Systematic Review and Expert Insight.

BACKGROUND: Sport-related structural brain injury (SRSBI) is intracranial pathology incurred during sport. Management mirrors that of non-sport-related brain injury. An empirical vacuum exists regarding return to play (RTP) following SRSBI. OBJECTIVE: To provide key insight for operative management and RTP following SRSBI using a (1) focused systematic review and (2) survey of expert opinions. METHODS: A systematic literature review of SRSBI from 2012 to present in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and a cross-sectional survey of RTP in SRSBI by 31 international neurosurgeons was conducted. RESULTS: Of 27 included articles out of 241 systematically reviewed, 9 (33.0%) case reports provided RTP information for 12 athletes. To assess expert opinion, 31 of 32 neurosurgeons (96.9%) provided survey responses. For acute, asymptomatic SRSBI, 12 (38.7%) would not operate. Of the 19 (61.3%) who would operate, midline shift (63.2%) and hemorrhage size > 10 mm (52.6%) were the most common indications. Following SRSBI with resolved hemorrhage, with or without burr holes, the majority of experts (>75%) allowed RTP to high-contact/collision sports at 6 to 12 mo. Approximately 80% of experts did not endorse RTP to high-contact/collision sports for athletes with persistent hemorrhage. Following craniotomy for SRSBI, 40% to 50% of experts considered RTP at 6 to 12 mo. Linear regression revealed that experts allowed earlier RTP at higher levels of play (ß = -0.58, 95% CI -0.111, -0.005, P = .033). CONCLUSION: RTP decisions following structural brain injury in athletes are markedly heterogeneous. While individualized RTP decisions are critical, aggregated expert opinions from 31 international sports neurosurgeons provide key insight. Level of play was found to be an important consideration in RTP determinations.

High Energy Side and Rear American Football Head Impacts Cause Obvious Performance Decrement on Video.

The objective of this study was to compare head impact data acquired with an impact monitoring mouthguard (IMM) to the video-observed behavior of athletes' post-collision relative to their pre-collision behaviors. A total of n = 83 college and high school American football players wore the IMM and were video-recorded over 260 athlete-exposures. Ex-athletes and clinicians reviewed the video in a two-step process and categorized abnormal post-collision behaviors according to previously published Obvious Performance Decrement (OPD) definitions. Engineers qualitatively reviewed datasets to check head impact and non-head impact signal frequency and magnitude. The ex-athlete reviewers identified 2305 head impacts and 16 potential OPD impacts, 13 of which were separately categorized as Likely-OPD impacts by the clinical reviewers. All 13 Likely-OPD impacts were in the top 1% of impacts measured by the IMM (ranges 40-100 g, 3.3-7.0 m/s and 35-118 J) and 12 of the 13 impacts (92%) were to the side or rear of the head. These findings require confirmation in a larger data set before proposing any type of OPD impact magnitude or direction threshold exists. However, OPD cases in this study compare favorably with previously published impact monitoring studies in high school and college American football players that looked for OPD signs, impact magnitude and direction. Our OPD findings also compare well with NFL reconstruction studies for ranges of concussion and sub-concussive impact magnitudes in side/rear collisions, as well as prior theory, analytical models and empirical research that suggest a directional sensitivity to brain injury exists for single high-energy impacts.

Long term delay in onset of prevertebral hematoma following anterior cervical discectomy and fusion: A case report.

Post-operative hematoma following anterior cervical discectomy and fusion (ACDF) is an uncommon but feared complication. Typically, these complications present in the immediate post-operative period. We present a case of a 51 year-old woman who underwent a C4-5 ACDF for left sided radicular pain. Her immediate post-operative course was uncomplicated, but she presented 6 weeks subsequently to the emergency department with neck swelling, difficulty swallowing, cough, and shortness of breath. She was found to have a 4.5 cm anterior neck hematoma with settling of the instrumentation and a new C4 vertebral fragment protruding anteriorly. She underwent evacuation of hematoma without clear evidence of a bleeding source. After several days of observation, she was discharged home and ultimately had resolution of her presenting symptoms. Most hematomas resulting in airway compromise appear in the immediate post-operative period, but a high index of suspicion must remain high in any patient with a prior anterior cervical surgery presenting with symptoms of pre-vertebral compression or respiratory compromise.

Laboratory and On-field Data Collected by a Head Impact Monitoring Mouthguard.

Although concussion continues to be a major source of acute and chronic injury in automotive, athletic and military arenas, concussion injury mechanisms and risk functions are ill-defined. This lack of definition has hindered efforts to develop standardized concussion monitoring, safety testing and protective countermeasures. Recent research has provided evidence of the role of repetitive head impact exposure as a predisposing factor for the onset of concussion using developed instrumented helmets and mouthguards.To overcome this knowledge gap, we have developed, tested and deployed a head impact monitoring mouthguard (IMM) system. In this study, we deployed the IMM system to gather high quality estimates of athlete head impacts in situ. And with enough longer-term data collection, potential concussive events or mild traumatic brain injuries (mTBIs) will be gathered and ideally will provide actionable risk-based threshold.

Treatment of holocord spinal epidural abscess via alternating side unilateral approach for bilateral laminectomy.

To date, this is the first reported case of the surgical management of a holocord epidural abscess done through level-skipping laminectomies. It is also the first reported case of these laminectomies being performed via an alternating side unilateral approach for this condition. A 51-year-old patient presenting with progressive lower extremity weakness secondary to a spinal epidural abscess extending from C4 to S1. A minimally disruptive method of relieving the spinal cord compression via evacuation of the abscess was employed successfully. This report demonstrates the efficacy of level skipping laminectomies via a unilateral approach for holocord epidural abscesses (extending 20 vertebral levels). Performing the laminectomies via a unilateral approach as well as alternating the side of the approach minimized iatrogenic instability risk. Both strategies were designed to minimize incision size, tissue disruption, and the amount of muscular weakness/imbalance postoperatively.

Anatomy and biomechanics of the spinal column and cord.

The field of biomechanics combines the disciplines of biology and engineering, attempting to quantitatively describe the complicated properties of biological materials. These properties depend not only upon the inherent attributes of its constituents but also upon how the constituents are arranged relative to each other. Its importance in understanding spinal column and spinal cord pathology cannot be overemphasized. This chapter is a primer on the application of biomechanical principles to the normal and pathological spine. The basic concepts of biomechanics will first be reviewed followed by a review of the structural anatomy of the osteoligamentous spinal column and the biomechanics of injury. Relevant spinal cord anatomy will then be addressed as well as current biomechanical theories of spinal cord injury.

Boxing and mixed martial arts: preliminary traumatic neuromechanical injury risk analyses from laboratory impact dosage data.

OBJECT: In spite of ample literature pointing to rotational and combined impact dosage being key contributors to head and neck injury, boxing and mixed martial arts (MMA) padding is still designed to primarily reduce cranium linear acceleration. The objects of this study were to quantify preliminary linear and rotational head impact dosage for selected boxing and MMA padding in response to hook punches; compute theoretical skull, brain, and neck injury risk metrics; and statistically compare the protective effect of various glove and head padding conditions. METHODS: An instrumented Hybrid III 50th percentile anthropomorphic test device (ATD) was struck in 54 pendulum impacts replicating hook punches at low (27-29 J) and high (54-58 J) energy. Five padding combinations were examined: unpadded (control), MMA glove-unpadded head, boxing glove-unpadded head, unpadded pendulum-boxing headgear, and boxing glove-boxing headgear. A total of 17 injury risk parameters were measured or calculated. RESULTS: All padding conditions reduced linear impact dosage. Other parameters significantly decreased, significantly increased, or were unaffected depending on padding condition. Of real-world conditions (MMA glove-bare head, boxing glove-bare head, and boxing glove-headgear), the boxing glove-headgear condition showed the most meaningful reduction in most of the parameters. In equivalent impacts, the MMA glove-bare head condition induced higher rotational dosage than the boxing glove-bare head condition. Finite element analysis indicated a risk of brain strain injury in spite of significant reduction of linear impact dosage. CONCLUSIONS: In the replicated hook punch impacts, all padding conditions reduced linear but not rotational impact dosage. Head and neck dosage theoretically accumulates fastest in MMA and boxing bouts without use of protective headgear. The boxing glove-headgear condition provided the best overall reduction in impact dosage. More work is needed to develop improved protective padding to minimize linear and rotational impact dosage and develop next-generation standards for head and neck injury risk.

Pathoanatomic basis for stretch-induced lumbar nerve root injury with a review of the literature.

OBJECTIVE: Persistent pain originating from a dysfunctional lumbar motion segment poses significant challenges in the clinical arena. Although the predominance of the existing spine literature has addressed nerve root compression as the principal cause of pain, it is equally likely that a stretch mechanism may be responsible for all or part of the pathology. METHODS: The literature supporting the role of stretch damage as a primary cause of nerve root injury and pain was systematically reviewed. Pathoanatomic considerations between nerve roots and juxtaposed environment are described and correlated with the available literature. Potential anatomic relationships that may lead to stretch-induced injury are delineated. RESULTS: A dynamic lumbar functional spinal unit that encloses a tethered nerve root can create significant stretch and/or compression. This phenomenon may be present in a variety of pathological conditions. These include anterior, posterior, and rotatory olisthesis as well as degenerative conditions such as the loss of disc interspace height and frank multisegment spinal deformity. Although numerous studies have demonstrated that stretch can result in nerve damage, the pathophysiology that may associate nerve stretch with chronic pain has yet to be determined. CONCLUSION: The current literature concerning stretch-related injury to nerve roots is reviewed, and a conceptual framework for its diagnosis and treatment is proposed and graphically illustrated using cadaveric specimens. The dynamic biomechanical and functional interrelationships between neural structures and adjacent connective tissue elements are particularly important in the face of spinal deformity.

Subaxial positional vertebral artery occlusion corrected by decompression and fusion.

STUDY DESIGN: A rare case of subaxial vertebral artery (VA) positional occlusion is reviewed and treatment methods discussed. OBJECTIVE: The decision process involved in treating subaxial VA positional occlusion is reviewed. SUMMARY OF BACKGROUND DATA: Bow Hunter stroke is a symptomatic vertebrobasilar insufficiency caused by stenosis or occlusion of the VA with physiologic head rotation. It most commonly occurs at the junction of C1 and C2 and less commonly as the VA enters the C6 transverse foramen. Rotational stenosis of the VA is quite rare during its passage through the foramen transversarium of C3-C6. METHODS: A 48-year-old gentleman presented describing syncopal episodes when he turns his head to the left side. Imaging revealed a congenitally narrowed right foramen transversarium and high-grade stenosis of the left VA when the head was turned to the left. A routine anterior cervical discectomy and fusion was performed with the addition of decompression of the left transverse foramen. RESULTS: Vascular imaging should be performed with the patient's head in both the neutral position and in the symptomatic position. Surgical treatment may be chosen if conservative therapies fail and generally has 1 of 2 goals-decompression of the VA or elimination of rotational movement at the affected level. Decisions between anterior and posterior decompressions may be influenced by the surgeon's comfort level with the approach and if the transverse foramen stenosis is caused mainly by an anterior (osteophytes at the uncinate process) or posterior (facet joint hypertrophy) process. The patient remains symptom-free after treatment. CONCLUSION: This report demonstrates the condition in the subaxial spine and describes successful treatment by fusion of the affected level combined with decompression of the foramen transversarium-a combination of previously described therapies.

Objectifying when to halt a boxing match: a video analysis of fatalities.

OBJECTIVE: Although numerous prestigious medical organizations have called for its abolishment, participation in the sport of boxing has reached an all-time high among both men and women, and its elimination is unlikely in the near future. Physicians should strive to increase boxing safety by improving the rules of competition, which have evolved minimally over the past two centuries. Currently, subjective criteria are used to determine whether or not a contest should be halted. Developing a standardized, objective method of determining when a contest should be halted would be a significant paradigm shift and could increase the safety of the sport's participants. This study analyzed the number and types of punches landed in a typical professional match, in bouts considered to be competitive and in those that ended in fatalities, to determine whether or not this would be a practical method of differentiating between these groups. METHODS: Three groups of professional boxing matches were defined at the beginning of the study: 1) a "fatal" group, consisting of bouts that resulted in the death of a participant; 2) a "classic" group that represented competitive matches; and 3) a "control" group of 4000 professional boxing matches representing the average bout. A computer program known as Punchstat (Compubox, Inc., Manorville, NY) was used in the objective analysis of these matches via videotape playback. RESULTS: Several statistically significant differences were discovered between matches that resulted in fatalities and the control group. These include the number of punches landed per round, the number of power punches landed per round, and the number of power punches thrown per round by losing boxers. However, when the fatal bouts were compared with the most competitive bouts, these differences were no longer evident. CONCLUSION: Based on the data analyzed between the control and fatal-bout groups, a computerized method of counting landed blows at ringside could provide sufficient data to stop matches that might result in fatalities. However, such a process would become less effective as matches become more competitive, and implementing such a change would significantly decrease the competitive nature of the sport. Therefore, other methods of quantifying acceleration-deceleration brain injuries are necessary to improve the safety of boxing.

Subdural hematomas in boxing: the spectrum of consequences.

Boxing is a violent sport in which every participant accepts the risk of brain damage or death. This sport has been linked to acute neurological injury and chronic brain damage. The most common life-threatening injury encountered by its participants is subdural hematoma (SDH), and the most feared consequence of chronic insult to the nervous system is dementia pugilistica, or punch drunkenness. Although advances in imaging and neuropsychological testing have improved our ability to diagnose these injuries, the unprecedented sensitivity and wide availability of these modalities have increased the detection of mild cognitive impairment and small, asymptomatic imaging abnormalities. The question has thus been raised as to where on the spectrum of these injuries an athlete should be permanently banned from the sport. In this report the authors describe six boxers who were evaluated for SDH sustained during participation in the sport, and who experienced remarkably different outcomes. Their presentations, clinical courses, and boxing careers are detailed. The athletes ranged in age from 24 to 55 years at the time of injury. Two were female and four were male; half of them were amateurs and half were professionals. Treatments ranged from observation only to decompressive craniectomy. Two of the athletes were allowed to participate in the sport after their injury (one following a lengthy legal battle), with no known sequelae. One boxer died within 48 hours of her injury and at least two suffered permanent neurological deficits. In a third, dementia pugilistica was diagnosed 40 years later, and the man died while institutionalized.

Sideline and ringside evaluation for brain and spinal injuries.

Participation in contact and collision sports carries an inherent risk of injury to the athlete, with damage to the nervous system producing the most potential for significant morbidity and death. Neurological injuries suffered during athletic competition must be treated promptly and correctly to optimize outcome, and differentiation between minor and serious damage is the foundation of sideline/ringside management of the injury. In this article the authors present a guide to the sideline or ringside identification and management of head and spinal injuries.

Participation in contact or collision sports in athletes with epilepsy, genetic risk factors, structural brain lesions, or history of craniotomy.

Despite a plethora of guidelines for return to play following mild head injury, a discussion of when and if an athlete should be allowed to participate in contact or collision sports if he or she sustains a structural brain lesion or after a head injury requiring craniotomy is lacking. The structural lesions discussed include arachnoid cyst, Chiari malformation Type I, cavum septum pellucidum, and the presence of ventriculoperitoneal shunts. Issues unique to this population with respect to the possibility of increased risk of head injury are addressed. The population of athletes with epilepsy and certain genetic risk factors is also discussed. Finally, the ability of athletes to participate in contact or collision sports after undergoing craniotomies for traumatic or congenital abnormalities is evaluated. Several known instances of athletes returning to contact sports following craniotomy are also reviewed.

A review of intrathecal morphine therapy related granulomas.

The development of catheter associated granulomatous masses in intrathecal morphine therapy is an uncommon, but potentially serious problem. While these systems have historically been used in patients with short life expectancies, more recently patients with pain from a benign source have benefited from this therapy, and new complications are being encountered secondary to the patients' longer life spans. Morphine is the most commonly used intrathecal opioid and evidence exists that the formation of granulomatous masses are related to the use of higher doses. When the patients' requirement of morphine increases significantly, the physician should be alert for signs of spinal cord compression, such as new neurological deficits, myelopathy, or radiculopathy. Patients that require these higher doses should be properly informed of the association with granulomas and their associated risks. Indolent infection may also be the etiology of granulomatous masses, and the presence of organisms, both aerobic and anaerobic, should be routinely investigated. Patients with catheter-associated granulomas appear to share several features. They exhibit the onset of symptoms several months following the initiation of intraspinal opioids and commonly present with an increase in pain that precedes signs and symptoms of neurological deterioration. While MRI might be the preferred method of detection of intrathecal granulomas, its cost and availability are prohibitive for routine screening. CT myelogram via pump side port injection of contrast can also be performed to detect catheter tip related granulomas/obstructions. Serial neurological examinations for new deficits may be performed and recorded during pump refill visits to recognize a granulomatous mass in its early stages. If an abnormality is identified, imaging studies are appropriate. Awareness of the condition and vigilance are the keys to successful management of this complication.

Intrathecal morphine therapy related granulomas: two case reports.

Intrathecal morphine infusions have historically been used in patients with short life expectancies. More recently, patients with pain from a benign source have benefited from this therapy. While use in this population has been well documented and found to be relatively safe, new complications are being encountered secondary to the patients' longer life spans. The development of granulomatous masses from catheter use in intrathecal morphine therapy is an uncommon, but potentially serious problem. At West Virginia University Hospital, we have implanted more than 700 intrathecal drug delivery systems (IT-DDS) since 1989, and have encountered two cases of granulomatous masses developing at the tip of the intrathecal catheter. This report describes these illustrative cases and provides a review of the literature.

Diagnostic pitfall of computed tomography in patients with superficial siderosis of the central nervous system.

Superficial siderosis of the central nervous system (SSCN) is a well-described entity with distinct clinical presentation as well as computed tomography (CT) and magnetic resonance imaging (MRI) findings. However, it is critical that when a patient previously diagnosed with SSCN undergoes CT on the brain at a later date, that this scan not be misinterpreted as a new subarachnoid hemorrhage (SAH) so unecessary repeated angiograms are not performed. This report describes such a situation and discusses unique CT findings in SSCN that have been under-recognized and under-emphasized. While conditions such as SAH should not be ruled out, they would be considered atypical. Combined with an adequate prior diagnostic testing history, physicians should proceed to MRI without subjecting the patient to repeat angiography.