Bernadette L. Koch

Achondroplasia and Cervicomedullary Compression: Prospective Evaluation and Surgical Treatment

The association between sudden death and cervicomedullary compression in infants with achondroplasia has been well described. Prospective clinical and imaging evaluations have been recommended to identify those infants with achondroplasia who are at risk of dying suddenly from respiratory arrest secondary to unrecognized cervicomedullary compression. Since 1988, we have prospectively evaluated 11 infants (average age 13 weeks) with achondroplasia who were asymptomatic for cervicomedullary compression on initial clinical evaluation. Craniocervical magnetic resonance imaging (MRI) findings included narrowing of the foramen magnum, effacement of the subarachnoid spaces at the cervicomedullary junction, abnormal intrinsic cord signal intensity and mild to moderate ventriculomegaly. Two patients with severe cord compression underwent immediate decompression. Two patients developed opisthotonic posturing within 3 months of evaluation and underwent foramen magnum decompression, including suboccipital craniectomy and atlantal laminectomy. Surgery in all cases revealed forward extension of the squamous portion of the occipital bone, thickened posterior rim of the foramen magnum and a dense fibrotic epidural band. There were no complications from surgery. Seven patients did not require surgery and were followed closely. All 11 patients remain asymptomatic at follow-up (mean 4.6 years; range 16 months to 7.3 years), and no patient has required a diversionary shunt procedure. The results of this prospective study confirm that early clinical and MRI evaluations are necessary to determine whether infants with achondroplasia have cervicomedullary compression. With early recognition, an immediate decompression can be performed safely to avoid serious complications associated with cervicomedullary compression, including sudden death.

Correlation between computed tomography and surgical findings in retropharyngeal inflammatory processes in children.

Retropharyngeal abscess (RPA) in children is a potentially life-threatening process which often requires immediate surgical intervention. Contrast enhanced computed tomography (CT) is utilized frequently to determine abscess versus cellulitis/phlegmon and aids in determining cases needing surgical drainage. The purpose of this retrospective study was to determine the accuracy of CT in distinguishing retropharyngeal abscess from cellulitis in children. The medical records of 32 children from 1989 to 1997 suspected of having a retropharyngeal abscess were reviewed. All patients included in the study underwent a CT scan as well as surgical exploration within 48 h of the scan. Two patients required two surgical procedures (n = 34). A comparison between CT results and operative findings was made to determine the accuracy of CT imaging in confirming the presence of RPA versus cellulitis. Suspected diagnosis of abscess or cellulitis/phlegmon on CT was confirmed at surgery in 25 of 34 cases (73.5%). The false positive rate of CT scan was 11.8% (4/34), while the false negative rate was 14.7% (5/34). Based on our results, CT is accurate in differentiating abscess from cellulitis in 73.5% of cases. Clinical findings, as well as radiologic findings, must be considered together prior to surgical drainage of a suspected retropharyngeal abscess in children.

Diagnostic and interventional ultrasound of the pediatric spine.

Abstract. Ultrasound is useful as a diagnostic tool in the evaluation of the pediatric spine, and can also help guide procedures in the interventional radiology suite or the operating room. This pictorial exhibit will display examples of diagnostic and interventional uses of ultrasound with respect to the pediatric spine.

Ultrasonographic imaging of sternocleidomastoid tumor of infancy.

A 6-week-old male infant presented with a 4-week history of a nontender right neck mass that was associated with torticollis and flexion of the neck to the right and slight rotation ofthe chin to the left. The patient was afebrile. There was no erythema of the overlying skin, and no additional masses were palpable. The patientwas the productof an uncomplicated full-term gestation via spontaneous vertex vaginal delivery.

Vesicoureteral reflux: subpopulations of patients defined by clinical variables

Background. The first imaging evaluation of the child with urinary tract infection (UTI) is often the same for all children, regardless of the childs clinical presentation. However, this approach is simplistic and ignores considerable differences in the frequency of abnormal pathophysiology in different subpopulations of children with UTI.¶Objective. Six clinical variables are evaluated as predictors of vesicoureteral reflux (VUR) in a large series of girls with UTI.¶Materials and methods. Data were collected from a consecutive series of 919 girls undergoing a first imaging evaluation for UTI. Six input variables were used: age, maximum body temperature (Tmax), number of UTIs, hospitalization, family history of childhood UTI, and rapidity of response to antibiotic therapy. The dependent variable was VUR. Data were enumerated and analyzed by logistic regression and the chi-square test.¶Results. VUR was present in 28.8 %. The percentage with VUR varied from 56.1 % for age < 6 months and Tmax L 38.5 °C to 13.0 % for age L 10 years and Tmax < 38.5 °C. The frequency of VUR was significantly lower in girls with Tmax < 38.5 °C in most age groups. Logistic regression demonstrated, when all clinical variables were taken together, that only age and Tmax were independent predictors of VUR.¶Conclusions. Girls with UTI should not be considered to be a homogeneous group. The frequency of VUR is related to Tmax and inversely to age. Data about these subpopulations should be used in deciding which girls should undergo cystography.

Orthopaedic injuries in children secondary to airbag deployment.

In recent years, airbag deployment has become recognized as a substantial contributor to vehicularrelated trauma in children. Particular attention has been focused on the mortality associated with these devices, with children younger than the age of ten years having a 34 percent higher risk of dying if they are passengers in a frontal motor-vehicle accident when dual airbags are present. However, there have been very few reports concerning orthopaedic injuries in children secondary to airbag deployment and, to the best of our knowledge, none concerning extremity injuries in nonfatally injured children. Airbag patents were first issued in the 1950s, but the technology lay dormant for virtually thirty years. In 1987, Federal Motor Vehicle Standard 208, Occupant Crash Protection, stating that airbags should be fitted in combination with three-point seat belts in all passenger automobiles, trucks, and vans, was released in the United States. A second federal mandate, in 1991, required airbag installation in all new automobiles by the beginning of model year 1998 and in all new light trucks by model year 1999. Currently, more than fifty-six million vehicles have driver-side airbags and nearly twenty-seven million have additional front-passenger-side airbags. Frontal impact in the range of about eight to fourteen miles (12.9 to 22.5 kilometers) per hour or greater will trigger airbag deployment. Any of up to five sensors located in the front-bumper region send electrical signals that ignite a sodium azide propellant. The combustion of the propellant liberates nitrogen gas, carbon dioxide, and an alkaline aerosol. The airbag inflates within fifty milliseconds of impact to cushion the passenger. This rapid series of events requires an inflation rate of about 150 to 200 miles (241.4 to 321.9 kilometers) per hour. Airbag-generated gas and debris have been shown to cause chemical irritation and burns in both adults and children who are crash victims. The impact of the rapidly inflating nylon fabric bag and the airbag module cover is thought to be the cause of the remainder of airbag injuries. Most reports of nonfatal airbag injury have focused on soft-tissue trauma, ocular injury, facial burns, and orbital fracture. On review of published reports of fatally injured children, the only orthopaedic injuries that we could identify were cervical spine injury and decapitation. Cervical spine injury also has been reported in several nonfatally injured children. To the best of our knowledge, the current report is the first to describe airbag-related extremity injuries in a child who survived a collision. Although adults are becoming increasingly more accustomed to wearing seat belts, it is alarming that 40 percent of children traveling in motor vehicles are unrestrained. Even when a child safety seat is used, it is used improperly up to 80 percent of the time. Review of the 1996 statistics revealed that 1701 children younger than fifteen years of age died as passengers in motor-vehicle collisions. The National Highway Traffic Safety Administration (NHTSA) reported that 55 percent of children who were involved in these fatal collisions were completely unrestrained. NHTSA also reported that only two of thirty-two fatal injuries caused by airbag deployment from January 1993 to November 1996 were sustained by children who were properly restrained in the front seat by lap and shoulder belts. The recent guidelines released by NHTSA *No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. No funds were received in support of this study. †Children’s Hospital Medical Center, Cincinnati, 3333 Burnet Avenue, Cincinnati, Ohio 45229-3039.

Central nervous system relapse of treated stage IV neuroblastoma.

Abstract Neuroblastoma is the most common extracranial solid tumor in pediatrics. The long-term survival of patients with advanced-stage neurobastoma has remarkably improved secondary to aggressive treatment protocols including autologous bone marrow transplant (BMT). As a result, a different natural history of this disease is being reported with unusual, late manifestations. The central nervous system (CNS), once a rare site of disease, is being involved with increasing frequency. Appropriate neuroimaging in these patients is important. Two cases of patients with treated stage IV neuroblastoma who developed isolated CNS metastases are presented. The proposed pathogenesis and neuroradiologic manifestations of this complication are reviewed.