Stingers, cervical cord neurapraxia, and stenosis

Congenital Cervical Stenosis: a Review of the Current Literature

PURPOSE OF REVIEW

Congenital cervical stenosis (CCS) is a phenomenon in which an individual has a narrow canal due to abnormal anatomy which can present with earlier degenerative symptoms due to a reduced sagittal diameter. The diagnosis of CCS is important to individual treatment and preventative measures. Often, athletes are warned against sport participation that may cause damage to the cervical spine. There may be a predisposition in certain populations, but lack of data limits conclusions. The current review investigates recent literature on the definition, pathoanatomy, clinical presentation, and management of CCS. It specifically interrogates potential populations predisposed to this condition.

RECENT FINDINGS

The current literature reveals a potential predisposition for CCS in the black population when compared to the white population; however, many studies do not report race when discussing CCS patients. The lack of data limits a consensus on specific populations with a congenitally narrow canal. CCS may be more prevalent in specific populations. With knowledge of populations more at risk for this condition, physicians and teams can be alert when evaluating players and young adults. Furthermore, this may provide insight into risk for symptoms with degenerative disease. These findings introduce an avenue for further research into CCS.

On-Field Management of Suspected Spinal Cord Injury

Acute spinal cord injuries in athletes are rare. However, on-field management of such injuries requires a well-planned approach from a team of well-trained medical staff. Athletes wearing protective gear should be handled with care; a primary survey should be conducted to rule out life-threatening injury while concomitantly immobilizing the spine. Treatment with steroids or hypothermia have not been shown to be beneficial, ultimately time to surgery provides the athlete with the best chance of a good outcome.

Strain stiffening of peripheral nerves subjected to longitudinal extensions in vitro

The mechanical response of peripheral nerves is crucial to understand their physiological and pathological conditions. However, their response to external mechanical solicitations is still partially unclear, since peripheral nerves could behave in a quite complex way. In particular, nerves react to longitudinal strains increasing their stiffness to keep axons integrity and to preserve endoneural structures from overstretch. In this work, the strain stiffening of peripheral nerves was investigated in vitro through a recently introduced computational framework, which is able to theoretically reproduce the experimental behaviour of excised tibial and sciatic nerves. The evolution and the variation of the tangent modulus of tibial and sciatic nerve specimens were quantitatively investigated and compared to explore how stretched peripheral nerves change their instantaneous stiffness.

Acute management of cervical spine trauma

Traumatic cervical spine injuries represent a significant cause of morbidity and mortality in sports. Appropriate management of such injuries is critical to minimizing harm and facilitating optimal long-term recovery and outcome. Management strategies begin with emergency preparedness amongst sideline providers and extends to paramedic services and medical teams in the acute care setting. This chapter outlines the principles of treatment across the care continuum, with a primary focus on hospital-based care. Diagnostic imaging and equipment considerations are reviewed, with discussion of corticosteroid administration, therapeutic hypothermia, and traction of the cervical spine. Approaches to cervical spine stabilization and return to play are also detailed, with an emphasis on patient-centered care and individualized treatment approaches to the athlete.

Common peripheral nerve injuries in sport: diagnosis and management

Peripheral nerve injuries are unusual in sport but impact an athlete's safe return to play. Nerve injuries result from either acute trauma (most commonly in contact/collision sports) or from repetitive microtrauma and overuse. Diagnosis of overuse nerve injuries includes nerve localization and surrounding soft-tissue anatomy, and must account for possible causes of repetitive microtrauma, including biomechanics, equipment, training schedule, and recovery. Prognosis is related to the type of nerve injury. Management should not simply be rest and gradual return to sport but should address biomechanical and training predispositions to injury. Understanding the type of injury and the tissues involved will guide appropriate rehabilitation decisions. Recognizing acute care considerations and implementing appropriate strategies can help minimize secondary trauma to an area following acute injury.

A unified approach to model peripheral nerves across different animal species

Peripheral nerves are extremely complex biological structures. The knowledge of their response to stretch is crucial to better understand physiological and pathological states (e.g., due to overstretch). Since their mechanical response is deterministically related to the nature of the external stimuli, theoretical and computational tools were used to investigate their behaviour. In this work, a Yeoh-like polynomial strain energy function was used to reproduce the response of in vitro porcine nerve. Moreover, this approach was applied to different nervous structures coming from different animal species (rabbit, lobster, Aplysia) and tested for different amount of stretch (up to extreme ones). Starting from this theoretical background, in silico models of both porcine nerves and cerebro-abdominal connective of Aplysia were built to reproduce experimental data (R² > 0.9). Finally, bi-dimensional in silico models were provided to reduce computational time of more than 90% with respect to the performances of fully three-dimensional models.

Neurologic Injuries in Noncontact Sports

Noncontact sports are associated with a variety of neurologic injuries. Concussion, vascular injury (arterial dissection), and spinal cord trauma may be less common in noncontact sports, but require special attention from the sports neurologist. Complex regional pain disorders, muscle injury from repetitive use, dystonia, heat exposure, and vascular disorders (patent foramen ovale), occur with similar frequency in noncontact and contact sports. Management of athletes with these conditions requires an understanding of the neurologic consequences of these disorders, the risk of injury with return to play, and consideration for the benefits of exercise in health restoration and disease prevention.

Severe Brachial Plexus Injuries in American Football

This article reports a series of severe permanent brachial plexus injuries in American football players. The authors describe the mechanisms of injury and outcomes from a more contemporary treatment approach in the form of nerve transfer tailored to the specific injuries sustained. Three cases of nerve transfer for brachial plexus injury in American football players are discussed in detail. Two of these patients regained functional use of the extremity, but 1 patient with a particularly severe injury did not regain significant function. Brachial plexus injuries are found along a spectrum of brachial plexus stretch or contusion that includes the injuries known as "stingers." Early identification of these severe brachial plexus injuries allows for optimal outcomes with timely treatment. Diagnosis of the place of a given injury along this spectrum is difficult and requires a combination of imaging studies, nerve conduction studies, and close monitoring of physical examination findings over time. Although certain patients may be at higher risk for stingers, there is no evidence to suggest that this correlates with a higher risk of severe brachial plexus injury. Unfortunately, no equipment or strengthening program has been shown to provide a protective effect against these severe injuries. Patients with more severe injuries likely have less likelihood of functional recovery. In these patients, nerve transfer for brachial plexus injury offers the best possibility of meaningful recovery without significant morbidity. [ Orthopedics. 2016; 39(6):e1188-e1192.].

Incidence of Stingers in Young Rugby Players

BACKGROUND

A stinger is a type of neurapraxia of the cervical roots or brachial plexus and represents a reversible peripheral nerve injury. The incidence of and major risk factors for stingers among young rugby players remain uninvestigated.

PURPOSE

To investigate the incidence, symptoms, and intrinsic risk factors for stingers in elite rugby union teams of young players.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

A total of 569 male rugby players, including 358 players from 7 high school teams and 211 players from 2 university teams, were investigated using self-administered preseason and postseason questionnaires.

RESULTS

The prevalence of a history of stingers was 33.9% (95% CI, 30.3-37.9), and 20.9% (119/569) of players experienced at least 1 episode of a stinger during the season (34.2 [95% CI, 26.2-42.1] events per 1000 player-hours of match exposure). The reinjury rate for stingers per season was 37.3% (95% CI, 30.4-44.2). Using the multivariate Poisson regression method, a history of stingers in the previous season and the grade and position of the player were found to be risk factors for stingers during the current season. The mean severity of injury was 2.9 days, with 79.3% (191/241) of the players not losing any time from playing after sustaining a stinger injury and 5.8% (14/241) of the players recovering within more than 14 days. The most frequent symptom was numbness in the unilateral upper extremity, and the most severe symptom was weakness of grasping (mean severity, 6 days). A logistic regression analysis indicated that a history of stingers in the previous season and an injury with more than 3 symptoms, especially motor weakness, were correlated with the severity of injury.

CONCLUSION

Young rugby players with a history of stingers have a significantly high rate of repeat injuries. Although nearly 80% of the players experienced only minimal (0-1 day) time loss injuries, neurological deficits sometimes last beyond 1 month. A history of stingers was identified to be the strongest risk factor for injuries and for lasting symptoms. This information may be useful for planning the proper treatment for stingers in young rugby players.

The envelope of motion of the cervical spine and its influence on the maximum torque generating capability of the neck muscles

The posture of the head and neck is critical for predicting and assessing the risk of injury during high accelerations, such as those arising during motor accidents or in collision sports. Current knowledge suggests that the head's range-of-motion (ROM) and the torque-generating capability of neck muscles are both dependent and affected by head posture. A deeper understanding of the relationship between head posture, ROM and maximum torque-generating capability of neck muscles may help assess the risk of injury and develop means to reduce such risks. The aim of this study was to use a previously-validated device, known as Neck Flexibility Tester, to quantify the effects of head's posture on the available ROM and torque-generating capability of neck muscles. Ten young asymptomatic volunteers were enrolled in the study. The tri-axial orientation of the subjects' head was controlled via the Neck Flexibility Tester device. The head ROM was measured for each flexed, extended, axially rotated, and laterally bent head's orientation and compared to that in unconstrained neutral posture. Similarly, the torque applied about the three anatomical axes during Isometric Maximum Voluntary Contraction (IMVC) of the neck muscles was measured in six head's postures and compared to that in fully-constrained neutral posture. The further from neutral the neck posture was the larger the decrease in ROM and IMVC. Head extension and combined two-plane rotations postures, such as extension with lateral bending, produced the largest decreases in ROM and IMVC, thus suggesting that these postures pose the highest potential risk for injury.

Behavioral and anatomical consequences of repetitive mild thoracic spinal cord contusion injury in the rat

Moderate and severe spinal cord contusion injuries have been extensively studied, yet much less is known about mild injuries. Mild contusions result in transient functional deficits, proceeding to near-complete recovery, but they may render the spinal cord vulnerable to future injuries. However, to date there have been no appropriate models to study the behavioral consequences, anatomical changes, and susceptibility of a mild contusion to repeated injuries, which may occur in children as well as adults during competitive sport activities. We have developed a novel mild spinal cord contusion injury model characterized by a sequence of transient functional deficits after the first injury and restoration to near-complete motor and sensory function, which is then followed up by a second injury. This model can serve not only to study the effects of repeated injuries on behavioral and anatomical changes, but also to examine the relationship between successive tissue damage and recovery of function. In the present study, we confirmed that mild thoracic spinal cord contusion, utilizing the NYU impactor device, resulted in localized tissue damage, characterized by a cystic cavity and peripheral rim of spared white matter at the injury epicenter, and rapid functional recovery to near-normal levels utilizing several behavioral tests. Repeated injury after 3weeks, when functional recovery has been completed, resulted in worsening of both motor and sensory function, which did not recover to prior levels. Anatomical analyses showed no differences in the volumes of spared white matter, lesion, or cyst, but revealed modest extension of lesion area rostral to the injury epicenter as well as an increase in inflammation and apoptosis. These studies demonstrate that a mild injury model can be used to test efficacy of treatments for repeated injuries and may serve to assist in the formulation of policies and clinical practice regarding mild SCI injury and spinal concussion.

Brachial neuropraxia in Canadian Atlantic University sport football players: what is the incidence of "stingers"?

OBJECTIVES

The objectives of this study were (1) to determine the incidence of brachial neuropraxia (stingers) among varsity football players during the 2010 season; (2) to determine if associations exist between sustaining a stinger and previous history of stingers, years played, equipment, age, body mass index (BMI), and conditioning; and (3) to provide descriptive statistics regarding stingers and position played, symptoms, activity during injury, mechanism of tackling, and reporting of stingers.

DESIGN

Retrospective.

SETTING

Canadian Atlantic University Sport football league.

PARTICIPANTS

Two hundred forty-four players.

ASSESSMENT OF RISK FACTORS

Two written questionnaires.

MAIN OUTCOME MEASURES

Number of players experiencing stingers that occurred during the 2010 season.

RESULTS

The incidence was 26% (64 of 244). A multivariate analysis revealed that previous history of a stinger (P < 0.0001) and years played (P = 0.0018) were associated with sustaining a stinger. There was no statistically significant effect related to additional equipment, a player's age, BMI, or participation in a strength training program. Linebackers, offensive linemen, and wide receivers had the highest incidence of stingers. The most frequent symptoms reported were tingling, numbness, burning, and weakness. Of all stingers sustained, only 59% (38 of 64) were reported to medical staff.

CONCLUSIONS

Stingers are a common injury in Canadian university football and are underreported to medical staff. Education of players at increased risk is needed.

Predicting chronic stinger syndrome using the mean subaxial space available for the cord index

A 21-year-old division I collegiate football player who had a history of several stingers presented with 5 days of persistent left neck and shoulder pain associated with paresthesias and upper extremity weakness. His symptoms began immediately during a game when he was struck on the right side of his helmet, which induced a compression-extension mechanism of injury to his neck. Clinical and electrodiagnostic evaluation was consistent with a left C5 radiculopathy, but magnetic resonance imaging of the cervical spine yielded normal results. The mean subaxial cervical space available for the cord (MSCSAC) index is a novel tool to predict chronic stinger syndrome. It is calculated by subtracting the sagittal diameter of the spinal cord from the disc-level sagittal diameter of the spinal canal at levels C3 through C6 and then averaging these values. A cutoff of < 4.3 mm has been shown to predict a greater-than-13-fold increase in risk of developing chronic stinger syndrome. This patient had a MSCSAC index of 3.2 mm, which correlated with his history of multiple stingers. The MSCSAC index may be a useful tool to help counsel athletes on the risk of developing future stingers, although more extensive research on this measurement tool is indicated.

Pediatric cervical spine injuries: a comprehensive review

INTRODUCTION

Cervical spine injuries can be life-altering issues in the pediatric population. The aim of the present paper was to review this literature.

CONCLUSIONS

A comprehensive knowledge of the special anatomy and biomechanics of the spine of children is essential in diagnosis and treating issues related to spine injuries.

High-energy contact sports and cervical spine neuropraxia injuries: what are the criteria for return to participation?

STUDY DESIGN

Clinically based systematic review.

OBJECTIVE

To define optimal clinical care for patients after sport-related neuropraxic injuries using a systematic review supported with expert opinion.

SUMMARY OF BACKGROUND DATA

Athletes who participate in contact sports may experience cervical cord neuropraxia, with bilateral motor or sensory symptoms such as burning, numbness, or loss of sensation referable to the cervical spinal cord. The symptoms last from minutes to hours, but recovery is usually believed to be complete. The underlying condition is cervical spinal stenosis that predisposes the athlete to a transient compression or concussive injury to the spinal cord.

METHODS

Focused questions on the treatment of cervical spine sport-related injuries resulting in transient neuropraxia were refined by a panel of spine traumatology surgeons consisting of fellowship-trained neurologic and orthopedic surgeons. Medical subject heading keywords were searched through MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews to identify pertinent English-language abstracts and articles whose focus was human subjects. The quality of literature was rated as high, moderate, low, or very low. The proposed questions were answered using the Grading of Recommendations Assessment, Development and Evaluation evidence-based review system. These treatment recommendations were rated as either strong or weak based on the quality of evidence and clinical expertise.

RESULTS

The literature searches revealed low and very low quality evidence with no prospective or randomized studies. One hundred fifty-three pertinent articles were identified; these were supplemented with additional articles to form an evidentiary table with 17 original articles containing unique patient data.

CONCLUSION

Literature regarding the optimal treatment of patients with transient neuropraxia is of low quality. On the basis of expert opinion, there was a recommendation that a return to full participation in high-energy contact sports could be based on radiographic findings: patients with transient neuropraxia without stenosis could return as a strong recommendation, whereas stenotic patients could not return as a weak recommendation. Furthermore, a strong recommendation was made to permit players to return to full participation after decompression with a single-level anterior cervical fusion.

Mortality resulting from head injury in professional boxing: case report

BACKGROUND

The majority of boxing-related fatalities result from traumatic brain injury. Biomechanical forces in boxing result in rotational acceleration with resultant subdural hematoma and diffuse axonal injury.

OBJECTIVE

Given the inherent risk and the ongoing criticism boxing has received, we evaluated mortalities associated with professional boxing.

METHODS

We used the Velazquez Fatality Collection of boxing injuries and supplementary sources to analyze mortality from 1950 to 2007. Variables evaluated included age at time of death, association with knockout or other outcome of match, rounds fought, weight class, location of fight, and location of preterminal event.

RESULTS

There were 339 mortalities between 1950 and 2007 (mean age, 24 +/- 3.8 years); 64% were associated with knockout and 15% with technical knockout. A higher percentage occurred in the lower weight classes. The preterminal event occurred in the ring (61%), in the locker room (17%), and outside the arena (22%). We evaluated for significant changes after 1983 when championship bouts were reduced from 15 to 12 rounds.

CONCLUSION

There was a significant decline in mortality after 1983. We found no significant variables to support that this decline is related to a reduction in rounds. Rather, we hypothesize the decline to be the result of a reduction in exposure to repetitive head trauma (shorter careers and fewer fights), along with increased medical oversight and stricter safety regulations. Increased efforts should be made to improve medical supervision of boxers. Mandatory central nervous system imaging after a knockout could lead to a significant reduction in associated mortality.

Cervical spine injuries in children: attention to radiographic differences and stability compared to those in the adult patient

The relative rarity of pediatric cervical spine injuries can impede rapid response and efficient care of this patient population. An understanding of the unique anatomical, radiographic, and biomechanical characteristics of the pediatric cervical spine is essential to the appropriate care of these challenging patients. Patterns of injury, diagnosis, and issues related to operative and nonoperative management are discussed with a focus on the developing spine. Our aim is to improve the understanding of traumatic cervical spine injuries in children for all practitioners involved with their care.

Medical conditions affecting sports participation

Children and adolescents with medical conditions present special issues with respect to participation in athletic activities. The pediatrician can play an important role in determining whether a child with a health condition should participate in certain sports by assessing the child's health status, suggesting appropriate equipment or modifications of sports to decrease the risk of injury, and educating the athlete, parent(s) or guardian, and coach regarding the risks of injury as they relate to the child's condition. This report updates a previous policy statement and provides information for pediatricians on sports participation for children and adolescents with medical conditions.

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.

Cervical stenosis in a professional rugby league football player: a case report

Background

This paper describes a case of C7 radiculopathy in a professional rugby league player after repeated cervical spine trauma. The report outlines the management of the patient following an acute cervical hyperflexion injury with chiropractic manipulation and soft tissue therapies. It also presents a change in approach to include distractive techniques on presentation of a neurological deficit following re-injury. The clinical outcomes, while good, were very dependent upon the athlete restricting himself from further trauma during games, which is a challenge for a professional athlete.

Case presentation

A 30-year old male front row Australian rugby league player presented complaining of neck pain after a hyperflexion and compressive injury during a game. Repeated trauma over a four month period resulted in radicular pain. Radiographs revealed decreased disc height at the C5-C6 and C6-C7 levels and mild calcification within the anterior longitudinal ligament at the C6-C7 level. MRI revealed a right postero-lateral disc protrusion at the C6-C7 level causing a C7 nerve root compression.

Conclusion

Recommendations from the available literature at the present time suggest that conservative management of cervical discogenic pain and disc protrusion, including chiropractic manipulation and ancillary therapies, can be successful in the absence of progressive neurological deficit. The current case highlights the initial successful management of a football athlete, and the later unsuccessful management. This case highlights the issues involvement in the management of a collision sport athlete with a serious neck injury.

Management of Common Neurologic Conditions in Sports

Neurological conditions are common in athletes. Trauma can cause direct central (eg, concussion or hemorrhage) or peripheral (eg, stinger) injury. Also, as neurological conditions in athletes become better understood, more people who have pre-existing conditions are becoming involved in organized sports. This article reviews assessment and initial management of head injury, stingers, seizures, and headaches. Return-to-play criteria are also discussed.

Medicolegal issues in sports medicine

This article reviews medicolegal issues in sports medicine. Nonmusculoskeletal medical conditions discussed include cardiac abnormalities, heat illness, and concussion in the athlete. Musculoskeletal injuries with the greatest potential for litigation, knee dislocation, and cervical spine trauma, are also reviewed. We provide legal case examples and discuss evaluation and treatment strategies to assist the medical team in the care of athletes.