Lauren W. Averill

Obstructive airway in Morquio A syndrome, the past, the present and the future

Patients with severe tracheal obstruction in Morquio A syndrome are at risk of dying of sleep apnea and related complications. Tracheal obstruction also leads to life-threatening complications during anesthesia as a result of the difficulty in managing the upper airway due to factors inherent to the Morquio A syndrome, compounded by the difficulty in intubating the trachea. A detailed description of the obstructive pathology of the trachea is not available in the literature probably due to lack of a homogenous group of Morquio A patients to study at any one particular center. We present a series of cases with significant tracheal obstruction who were unrecognized due to the difficulty in interpreting tracheal narrowing airway symptoms. Our goal is to provide the guidelines in the management of these patients that allow earlier recognition and intervention of tracheal obstruction. Sagittal MRI images of the cervical spine of 28 Morquio A patients (12±8.14years) showed that19/28 (67.9%) patients had at least 25% tracheal narrowing and that narrowing worsened with age (all 8 patients over 15years had greater than 50% narrowing). Eight out of 28 patients were categorized as severe (>75%) tracheal narrowing when images were evaluated in neutral head and neck position. Of the 19 patients with tracheal narrowing, compression by the tortuous brachiocephalic artery was the most common cause (n=15). Evidence of such tracheal narrowing was evident as early as at 2years of age. The etiology of tracheal impingement by the brachiocephalic artery in Morquio A appears to be due to a combination of the narrow thoracic inlet crowding structures and the disproportionate growth of trachea and brachiocephalic artery in relationship to the chest cavity leading to tracheal tortuosity. In conclusion, tracheal narrowing, often due to impression from the crossing tortuous brachiocephalic artery, increases with age in Morquio A patients. Greater attention to the trachea is needed when evaluating cervical spine MRIs as well as other imaging and clinical investigations, with the goal of establishing a timely treatment protocol to reduce the mortality rate in this patient population.

Septic Arthritis and Concern for Osteomyelitis in a Child with Rat Bite Fever

ABSTRACT Rat bite fever is a rare infection usually caused by Streptobacillus moniliformis. A case of septic arthritis and possible osteomyelitis as sequelae of rat bite fever in a pediatric patient is described.

Fetal Brain Magnetic Resonance Imaging Findings In Congenital Cytomegalovirus Infection With Postnatal Imaging Correlation.

Fetal brain magnetic resonance imaging (MRI) is a powerful tool in the diagnosis of symptomatic congenital cytomegalovirus infection, requiring a detailed search for specific features. A combination of anterior temporal lobe abnormalities, white matter lesions, and polymicrogyria is especially predictive. Fetal MRI may provide a unique opportunity to detect anterior temporal cysts and occipital horn septations, as dilation of these areas may decrease later in development. Cortical migration abnormalities, white matter abnormalities, cerebellar dysplasia, and periventricular calcifications are often better depicted on postnatal imaging but can also be detected on fetal MRI. We present the prenatal brain MRI findings seen in congenital cytomegalovirus infection and provide postnatal imaging correlation, highlighting the evolution of findings at different times in prenatal and postnatal developments.

Chronic recurrent multifocal osteomyelitis: typical patterns of bone involvement in whole-body bone scintigraphy.

Chronic recurrent multifocal osteomyelitis (CRMO) is an autoinflammatory bone disease of unknown etiology. It affects children and adolescents predominantly and occurs mostly in the female population. It is characterized by the insidious onset of pain and swelling, with a fluctuating clinical course of relapses and remissions. Typically, several bones are affected, either synchronously or metachronously, and bilateral involvement is common. CRMO most commonly affects the metaphysis of long bones, especially the tibia, femur, and clavicle. The spine, pelvis, ribs, sternum, and mandible may also be affected. Although lesions are mostly multiple, patients may present with a single symptomatic focus. Radiographic findings may be negative early in the course of the disease. Bone scintigraphy is useful in determining the presence of abnormality and the extent of disease. The imaging and clinical features of CRMO overlap with those of infectious osteomyelitis, bone malignancy, and inflammatory arthritis. Nonetheless, CRMO can be confidently diagnosed with the recognition of typical imaging patterns in the appropriate clinical setting. This article reviews imaging findings with special emphasis on bone scintigraphy and specific disease sites.

Update on Pediatric Leukemia and Lymphoma Imaging

Together, leukemia and lymphoma account for half of all childhood malignancies. Leukemia and lymphoma arise from similar cell lines and can have overlapping imaging features; however, the clinical presentation, imaging strategies, and treatment protocols can vary substantially based on the specific subtype. Although imaging does not play a central role in staging or monitoring disease in childhood leukemia, findings on imaging may be the first indication of the diagnosis. Advanced imaging, especially positron emission tomography/computed tomography, has moved to the forefront of staging and treatment response evaluation in Hodgkins disease and non-Hodgkins lymphoma. Imaging also plays a key role in evaluating the myriad of treatment complications that are commonly seen with chemotherapy and associated neutropenia. Future efforts will be largely focused on decreasing radiation exposure to these children, utilizing reduced or radiation-free modalities, such as positron emission tomography/magnetic resonance and diffusion-weighted whole-body imaging with background suppression, as well as refining surveillance imaging strategies. The purpose of this article is to briefly review the classification of pediatric leukemia and lymphoma, illustrate common imaging findings at presentation throughout the body, describe staging and therapeutic response evaluation, and show a spectrum of commonly encountered complications of treatment.

Surgical Reconstruction for Severe Tracheal Obstruction in Morquio A Syndrome

Progressive tracheal obstruction is commonly seen in Morquio A syndrome and can lead to life-threatening complications. Although tracheostomy can address severe upper airway obstruction, lower airway obstruction, commonly associated with a narrow thoracic inlet and vascular compression, requires an alternative approach. We describe the case of a 16-year-old patient with Morquio A syndrome whose near-fatal tracheal obstruction was relieved by timely surgical tracheal vascular reconstruction with dramatic resolution of his respiratory symptoms.

Factors Related to Increased Ulnar Collateral Ligament Thickness on Stress Sonography of the Elbow in Asymptomatic Youth and Adolescent Baseball Pitchers

Background: Stress ultrasound (SUS) of the elbow has demonstrated changes in the anterior band of the ulnar collateral ligament (UCL) in professional and high school–aged pitchers. However, there have been no large reports correlating pitching history data with SUS changes in youth and adolescent baseball pitchers. Hypothesis: Changes of the UCL on SUS will correlate with pitching volume in youth and adolescent baseball pitchers. Study Design: Cross-sectional study; Level of evidence, 3. Methods: SUS of the elbow was performed in both elbows of 102 youth and adolescent baseball pitchers. UCL thickness and the width of the ulnohumeral joint, at rest and with 150 N of valgus stress, were measured using a standardized, instrumented device. Demographic data, arm measurements, and a pitching history questionnaire were recorded as well. The pitchers were separated into 2 groups based on age: group 1 (12-14 years) and group 2 (15-18 years). SUS findings of the dominant elbows were compared between the 2 groups. Correlation analysis and linear regression were used to identify relationships between SUS findings and pitching history data. Results: In all pitchers, the mean UCL thickness was 4.40 mm in the dominant elbow and 4.11 mm in the nondominant elbow (P =.03). There was no significant difference between elbows in any joint space characteristics. A comparison of group 1 versus group 2 demonstrated significant differences in UCL thickness (4.13 vs 4.96 mm; P < .001), resting joint space width (6.56 vs 4.04 mm; P < .001), and stressed joint space width (7.68 vs 4.07 mm; P < .001). There was no difference in the change in joint space width between the 2 groups (1.11 vs 0.76 mm; P = .05). The UCL was significantly thicker in pitchers who threw more than 67 pitches per appearance (4.69 vs 4.14 mm), who pitched more than 5 innings per appearance (4.76 vs 4.11 mm), and who had more than 5.5 years of pitching experience (4.71 vs 4.07 mm; P < .001). Linear regression demonstrated that age, weight, and pitches per appearance (R 2 = 0.114, 0.370, and 0.326, respectively) significantly correlated with UCL thickness. Conclusion: These findings suggest that UCL thickness increases as pitchers get older and heavier and as they increase their pitch volumes.

Pre- and postoperative imaging of adolescents undergoing laparoscopic adjustable gastric banding surgery.

BackgroundAs childhood obesity rates rise, laparoscopic adjustable gastric banding (LAGB) is being investigated as a bariatric surgical option in adolescents.ObjectiveTo examine pre- and postoperative imaging in adolescents undergoing LAGB, describe the most common abnormal preoperative imaging findings, and illustrate the typical appearance and variants on postoperative upper-gastrointestinal (UGI) examinations.Materials and methodsA retrospective chart review was performed of all adolescents from 2008 to 2010 undergoing LAGB at a single tertiary-care pediatric hospital. The picture archiving and communication system was queried for all imaging obtained before and after surgery. Postoperative UGI studies were analyzed for common patterns.ResultsTwenty-seven obese adolescents who underwent LAGB were identified. Twenty-five had preoperative imaging, most commonly a UGI study (81.5%). Eight UGI studies were abnormal but did not impact surgery. Preoperative chest and neck radiographs were also common. Intraoperative imaging was rare. Seventy-three postoperative UGI studies were performed on 22 children (range, 2–12 studies). A common postoperative imaging pattern was observed in 19/22 (86%) children. No complications were observed.ConclusionThe most common pre- and postoperative imaging studies in adolescents undergoing LAGB are UGI studies. Pediatric radiologists should be familiar with the imaging of LAGB as this procedure becomes increasingly common.

Natural history of Morquio A patient with tracheal obstruction from birth to death

Morquio A syndrome (mucopolysaccharidosis IVA, MPS IVA) is a lysosomal storage disease caused by a deficiency of N-acetylgalactosamine-6-sulfate sulfatase, resulting in systemic accumulation of the partially degraded glycosaminoglycans (GAGs), keratan sulfate and chondroitin-6-sulfate. The accumulation of these GAGs leads to distinguishing features as skeletal dysplasia with disproportionate dwarfism, short neck, kyphoscoliosis, pectus carinatum, tracheal obstruction, coxa valga, genu valgum, and joint laxity. In the absence of autopsied cases and systemic analysis of multiple tissues, the pathological mechanism of the characteristic skeletal dysplasia associated with the disease largely remains a question. Here we report an autopsied case of a 23-year-old male with MPS IVA, who developed characteristic skeletal abnormalities by 4 months of age and died of severe tracheal obstruction and hypoventilation originating from respiratory muscle weakness from neurological cord deficit due to cord myelopathy at the age of 23. We analyzed postmortem tissues pathohistologically, including the thyroid, lung, lung bronchus, trachea, heart, aorta, liver, spleen, kidney, testes, humerus, knee cartilage, and knee ligament. Examination of the tissues demonstrated systemic storage materials in multiple tissues, as well as severely ballooned and vacuolated chondrocytes in the trachea, humerus, knee cartilage, and lung bronchus. This autopsied case with MPS IVA addresses the importance of tracheal obstruction for morbidity and mortality of the disease, and the pathological findings contribute to a further understanding of the pathogenesis of MPS IVA and the development of novel therapies.

Molecular genetics and metabolism, special edition: Diagnosis, diagnosis and prognosis of Mucopolysaccharidosis IVA

Mucopolysaccharidosis IVA (MPS IVA, Morquio A syndrome) is an autosomal recessive disorder caused by the deficiency of N-acetylgalactosamine-6-sulfate sulfatase. Deficiency of this enzyme leads to the accumulation of specific glycosaminoglycans (GAGs), chondroitin-6-sulfate (C6S) and keratan sulfate (KS), which are mainly synthesized in the cartilage. Therefore, the substrates are stored primarily in the cartilage and its extracellular matrix (ECM), leading to a direct impact on bone development and successive systemic skeletal spondylepiphyseal dysplasia. The skeletal-related symptoms for MPS IVA include short stature with short neck and trunk, odontoid hypoplasia, spinal cord compression, tracheal obstruction, obstructive airway, pectus carinatum, restrictive lung, kyphoscoliosis, platyspondyly, coxa valga, genu valgum, waddling gait, and laxity of joints. The degree of imbalance of growth in bone and other organs and tissues largely contributes to unique skeletal dysplasia and clinical severity. Diagnosis of MPS IVA needs clinical, radiographic, and laboratory testing to make a complete conclusion. To diagnose MPS IVA, total urinary GAG analysis which has been used is problematic since the values overlap with those in age-matched controls. Currently, urinary and blood KS and C6S, the enzyme activity of GALNS, and GALNS molecular analysis are used for diagnosis and prognosis of clinical phenotype in MPS IVA. MPS IVA can be diagnosed with unique characters although this disorder relates closely to other disorders in some characteristics. In this review article, we comprehensively describe clinical, radiographic, biochemical, and molecular diagnosis and clinical assessment tests for MPS IVA. We also compare MPS IVA to other closely related disorders to differentiate MPS IVA. Overall, imbalance of growth in MPS IVA patients underlies unique skeletal manifestations leading to a critical indicator for diagnosis.