Joshua J. Chern

Relationship between pharyngitis and peri‐odontoid pannus: A new etiology for some Chiari I malformations?

The pathophysiology underlying Chiari I malformations (CIMs) provides room for debate with several theories attempting to address this issue. We retrospectively reviewed many of our past patients with pediatric CIMs (specifically, those with peri‐odontoid pannus), and present a hypothesis for the development of the malformation in some of said patients. Our experience with the pediatric CIM has shown that almost 1 in 20 patients who present with symptoms is found to have a peri‐odontoid pannus. These masses ranged in size from 4 to 11 mm in diameter. Forty percent had a history of clinically significant pharyngitis or pharyngeal abscess. Pannus formation around the dens (odontoid) resulted in ventral compression of the craniocervical junction in each of these patients. Highlighting the hypermobility that causes such lesions, following fusion, the pannus and symptoms in several patients were diminished. Impairment of normal cerebrospinal fluid circulation out of the fourth ventricle and across the craniocervical junction appears to be a plausible endpoint in this discussion and a suitable explanation for some patients with CIM. Still, the mechanisms by which cerebrospinal fluid circulation is compromised may be variable and are not well understood. This is the first study dedicated to the evaluation of pannus formation in the CIM population. We hypothesize that pharyngeal inflammatory conditions contribute to the formation and progression of hindbrain herniation in a small subset of patients with CIMs. Clin. Anat. 28:602–607, 2015.

Sonographic determination of normal Conus Medullaris level and ascent in early infancy

IntroductionControversial reports exist in the literature regarding both the spinal level of the conus medullaris (CM) in normal infants and the age at which the CM achieves its adult level. Autopsy studies have demonstrated ascent continuing into early infancy while more recent imaging study series’ suggest the adult conus level is attained by the 40th postmenstrual week.MethodsThe authors conducted a retrospective review of 1,273 screening lumbar ultrasound studies performed over 5xa0years at a pediatric tertiary referral center. All patients were infants referred for initial imaging to rule out the presence of a tethered spinal cord. Referral sources included urban academic, urban private practice, and rural private practice pediatricians. After excluding studies lacking sufficient documentation (nu2009=u200990) and those reported as abnormal (nu2009=u2009106), 1,077 remained for review. The CM level and patient age in days were recorded from each study. Statistical analysis was performed using unpaired t testing and ANOVA for continuous variables; chi-square for categorical data.ResultsThe mean CM level for infants in group I (ages 0–30xa0days) was compared to those in groups II (31–60xa0days) and group III (61–100xa0days). Group I had a mean CM level of 0.125 and 0.2 vertebral segments lower than groups II and III (pu2009=u20090.0005 and <0.0001, respectively). ANOVA comparison of all three groups confirmed a rostral migratory trend (pu2009<u20090.001). The prevalence of CM level caudal to L2 in group I was 13xa0%, group II 11.4xa0%, and group III 4.7xa0%; also indicating a significant rostral trend (pu2009=u20090.004).ConclusionsRostral migration of CM level continues through the first few months of post-natal life, albeit of limited extent. Documentation of continued ascent in a neonate may obviate the need for magnetic resonance imaging.

Preventability of Pediatric 30-Day Readmissions following Ventricular Shunt Surgery

OBJECTIVEnTo compare the preventability of 30-day pediatric ventricular shunt readmissions using clinical and administrative data review.nnnSTUDY DESIGNnWe performed a retrospective chart review of one hundred forty-seven 30-day ventricular shunt readmissions at a tertiary pediatric center from May 2009-April 2013 under 2 scenarios: scenario 1 considered all ventricular shunt failures preventable; and scenario 2 considered shunt failures with excellent/good catheter positioning and no contributing deficiencies in care not preventable. Three physician reviewers independently assessed readmissions to determine their preventability and whether deficiencies in care existed that contributed to the readmission. We also evaluated the degree of interrater agreement in adjudicating readmission preventability.nnnRESULTSnOnly 42% of 30-day readmissions following ventricular shunt procedures were preventable when considering all shunt failures as preventable. When classifying shunts with excellent/good proximal catheter position as not preventable, 21% of ventricular shunt readmissions were deemed preventable. Interrater agreement on readmission preventability was high (kappa 0.88). Deficiencies in care existed in 29 readmissions (20%), the largest category being physician related, but not all deficiencies contributed to a readmission.nnnCONCLUSIONSnSignificant discrepancy exists in the preventability adjudication of ventricular shunt readmissions between administrative and chart review. Although using administrative data has determined that a majority of readmissions following pediatric ventricular shunt procedures are preventable, our review suggests a significantly lower degree of preventability.

Relationships between the posterior interosseous nerve and the supinator muscle: application to peripheral nerve compression syndromes and nerve transfer procedures.

BACKGROUND AND STUDY AIMSnLittle information can be found in the literature regarding the relationships of the posterior interosseous nerve (PIN) while it traverses the supinator muscle. Because compression syndromes may involve this nerve at this site and researchers have investigated using branches of the PIN to the supinator for neurotization procedures, the authors aim was to elucidate information about this anatomy.nnnMATERIALS AND METHODSnDissection was performed on 52 cadaveric limbs to investigate branching patterns of the PIN within the supinator muscle.nnnRESULTSnOn 29 sides, the PIN entered the supinator muscle as a single nerve and from its medial side provided two to four branches to the muscle. On 23 sides, the nerve entered the supinator muscle as two approximately equal-size branches that arose from the radial nerve on average 2.2 cm from the proximal edge of this muscle. In these cases, the medial of the two branches terminated on the supinator muscle, and the lateral branch traveled through the supinator muscle; in 13 specimens, it provided additional smaller branches to the supinator muscle. The length of PIN within the supinator muscle was 4 cm on average, and the diameter of its branches to the supinator muscle ranged from 0.8 to 1.1 mm. In 10 specimens, the PIN left the supinator muscle before the most distal aspect of the muscle. In two specimens with a single broad PIN, muscle fibers of the supinator muscle pierced the PIN as it traveled through it.nnnCONCLUSIONnThis knowledge of the anatomy of the PIN as it passes through the supinator muscle may be useful to neurosurgeons during decompressive procedures or neurotization.

Multicenter retrospective evaluation of the validity of the Thoracolumbar Injury Classification and Severity Score system in children

OBJECTIVE The Thoracolumbar Injury Classification and Severity Score (TLICS) system was developed to streamline injury assessment and guide surgical decision making. To the best of the authors knowledge, external validation in the pediatric age group has not been undertaken prior to this report. METHODS This study evaluated the use of the TLICS in a large retrospective series of children and adolescents treated at 4 pediatric medical centers (Texas Childrens Hospital, Childrens Healthcare of Atlanta, Riley Childrens Hospital, and Doernbecher Childrens Hospital). A total of 147 patients treated for traumatic thoracic or lumbar spine trauma between February 1, 2002, and September 1, 2015, were included in this study. Clinical and radiographic data were evaluated. Injuries were classified using American Spinal Injury Association (ASIA) status, Denis classification, and TLICS. RESULTS A total of 102 patients (69%) were treated conservatively, and 45 patients (31%) were treated surgically. All patients but one in the conservative group were classified as ASIA E. In this group, 86/102 patients (84%) had Denis type compression injuries. The TLICS in the conservative group ranged from 1 to 10 (mean 1.6). Overall, 93% of patients matched TLICS conservative treatment recommendations (score ≤ 3). No patients crossed over to the surgical group in delayed fashion. In the surgical group, 26/45 (58%) were ASIA E, whereas 19/45 (42%) had neurological deficits (ASIA A, B, C, or D). One of 45 (2%) patients was classified with Denis type compression injuries; 25/45 (56%) were classified with Denis type burst injuries; 14/45 (31%) were classified with Denis type seat belt injuries; and 5/45 (11%) were classified with Denis type fracture-dislocation injuries. The TLICS ranged from 2 to 10 (mean 6.4). Eighty-two percent of patients matched TLICS surgical treatment recommendations (score ≥ 5). No patients crossed over to the conservative management group. Eight patients (8/147, 5%) had a calculated TLICS of 4, which meant they were candidates for surgery or conservative therapy by TLICS criteria. Excluding these patients, the degree of agreement between TLICS and surgeon decision was deemed to be very good (κ = 0.878). CONCLUSIONS The TLICS results and recommendations matched treatment in 96% of conservative group cases. In the surgical group, TLICS recommendations matched treatment in 93% of cases. The TLICS recommendations and surgeon decision making displayed very good concordance. The TLICS appears to be effective in the classification of thoracic and lumbar spine injuries and in guiding treatment in the pediatric age group.

De novo AVM formation

Dear Editor: We read with great interest the recent report by Yeo and colleagues [2] describing two cases of de novo AVMs in children. Their cases and literature review provide further evidence that AVMs, especially in children, are dynamic lesions that can appear and change throughout a patient’s lifetime. Our recent publication [1], which was not included in their review, provides another case example of de novo formation of a pediatric AVM. Like the majority of patients described in their review, our patient had a history of a possible inciting event (a severe traumatic brain injury) that may have contributed to formation of the AVM. Additionally, the patient we described presented with seizures, as did one of the patients described by Yeo and colleagues. This reinforces the fact that new neurologic symptoms must be investigated with appropriate studies even in patients who have previously undergone neuroimaging.

The Central Role of Community-Practicing Pediatricians in Contemporary Concussion Care: A Case Study of Children's Healthcare of Atlanta's Concussion Program.

Increased lay media coverage of the long-term impact of concussions and the widespread adoption of “concussion laws” mandating professional clearance for returnto-play and return-to-learn are driving an increasing number of children with suspected concussions to seek clinical care. Providing concussion-specific decision support tools for community-practicing, pediatric care providers is critical to address both the surging demand and the need for practice guidance for clinicians unaccustomed to routinely treating concussion patients. To address these challenges in the contemporary management of youth concussions, a multidisciplinary group of clinicians at Children’s Healthcare of Atlanta (CHOA), a tertiary care pediatric hospital, developed a comprehensive, evidence-based, community concussion program. The core feature of the program was to enable community pediatricians to play the central role in managing these patients. Extensive partnering and education programs were instituted with the goal of ensuring that the necessary tools were readily available to support primary care physicians. Other elements of CHOA’s Concussion Program include providing appropriate tertiary support for those children who remain symptomatic beyond the expected course, partnering with statewide preventive programs, and supporting concussion-related research efforts. The design and implementation of the CHOA Concussion Program is presented here, with the hope that it will serve as a template for other communities. Increasing Case Load

Intramedullary placement of ventricular shunts: a review of using bone as a distal cerebrospinal absorption site in treating hydrocephalus

PurposeIntraosseous (IO) vascular access has been used since the Second World War and is warranted when there is an emergency and/or urgent need to replenish the vascular pool. Despite long-term and satisfactory results from delivering large quantities of intravenous fluid via the medullary space of bone, use of this space for a distant receptacle for cerebrospinal fluid (CSF) diversion has seldom been considered.MethodsThe current paper reviews the literature regarding the bony medullary space as a receptacle for intravenous fluid and CSF.ResultsPrevious authors have demonstrated the potential of the diploic space of the calvaria for CSF shunting. Pugh and colleagues tested the ability of the cranium to receive and absorb a small amount of tracer fluid.ConclusionThe literature suggests that intraosseous placement of ventricular diversionary shunts is an alternative to more traditional sites such as the pleural cavity and peritoneum. When these latter locations are not available or are contraindicated, placement in the medullary space of bone is another option available to the surgeon.

Clinical outcome of children with suspected shunt malfunction evaluated in the emergency department.

BACKGROUNDnPatients with cerebrospinal fluid shunts frequently present to the emergency department (ED) with suspected shunt malfunction. The outcome of those patients who were discharged from ED when shunt malfunction was deemed unlikely has not been previously documented.nnnOBJECTIVEnTo demonstrate there is no increase in severity or likelihood of harm for patients who are discharged directly from the ED after adequate evaluation, as compared to patients who were selected for inpatient hospitalization.nnnMETHODSnThe report screens 3080 ED visits between 2010 and 2013 made by patients with shunted hydrocephalus. ED visits preceded by another ED visit or neurosurgical procedures within 60 days were excluded. ED visits for reasons unrelated to shunt function were excluded, and 1943 visits met the inclusion criteria. Final dispositions from the ED included home (n = 1176), admission to neurosurgery service (n = 550), and admission to other services (n = 217). Subsequent events within 30 days, including ED visits and elective and nonelective shunt-related surgery, were reviewed.nnnRESULTSnThe clinical characteristics of the 3 groups were similar. Of patients discharged home from the ED, 19.0% returned to ED, and 4.5% required shunt-related surgeries. Of the patients admitted for observation, 18.7% returned to ED and 14.2% required shunt-related surgery. Of the patients admitted to other hospital services, 19.6% patients returned to the ED, with 2.0% requiring surgical intervention. There were no shunt-related mortalities in any of the 3 groups.nnnCONCLUSIONnChildren with cerebrospinal fluid shunts are often evaluated in the ED. Discharge from the ED, when suspicion for shunt malfunction is low, is an appropriate practice.

The Anterior Atlantodental Ligament: Its Anatomy and Potential Functional Significance

OBJECTIVEnKnowledge of the anatomy of the ligaments that unite the head to the neck is important to the clinician who treats patients with lesions in this region. Although the anatomy and function of the majority of these ligaments have been well described, some are relatively unknown. One of these includes the anterior atlantodental ligament (AADL). Our goal was to increase knowledge about the AADL.nnnMETHODSnWe dissected the craniocervical junction in sixteen adult cadavers and paid special attention to the presence and anatomy of the AADL.nnnRESULTSnThe AADL was found in 81.3% of specimens. The attachment of each ligament was consistent and traveled between the base of the anterior dens to the posterior aspect of the anterior arch of the atlas in the midline and just inferior to the fovea dentis. In 38.5% of specimens, there was some connection between the AADL and the anterior atlanto-occipital membrane. The ligament was roughly 4 × 4 × 4 mm in all specimens. With transection of the transverse ligament, the AADL could be made taut with posterior distraction of the dens. In addition, with left and right rotation of the atlantoaxial joint, the AADL became taut (less than 10°) before any tautness of the alar ligaments in all specimens.nnnCONCLUSIONSnThe AADL appears to resist posterior displacement of the dens and, with the alar ligaments, resists rotation. When present, the AADL contributes to the predental space. Knowledge of this ligament may aid in further understanding craniocervical stability and help in differentiating normal anatomy from pathology via imaging modalities.