An online, open source book focusing on ultrasound in tropical medicine and resource-limited environments. Our goal is to create an up-to-date and useful resource for those taking care of vulnerable patients around the globe.

Intraspinal rib head dislocation is an important but under-recognized consequence of dystrophic scoliosis in patients with neurofibromatosis 1 (NF1). To present clinical and imaging findings of intraspinal rib head dislocation in NF1. We retrospectively reviewed clinical presentation, imaging, operative reports and post-operative courses in four NF1 patients with intraspinal rib head dislocation and dystrophic scoliosis. We also reviewed 17 cases from the English literature. In each of our four cases of intraspinal rib head dislocation, a single rib head was dislocated on the convex apex of the curve, most often in the mid- to lower thoracic region. Cord compression occurred in half of these patients. Analysis of the literature yielded similar findings. Only three cases in the literature demonstrates the MRI appearance of this entity; most employ CT. All of our cases include both MRI and CT; we review the subtle findings on MRI. Although intraspinal rib head dislocation is readily apparent on CT, sometimes MRI is the only cross-sectional imaging performed. It is essential that radiologists become familiar with this entity, as subtle findings have significant implications for surgical management.

Background

Few studies exist to inform the extrapolated practice of irradiating children for heterotopic ossification (HO) prevention. We report the incidence of HO formation following prophylactic preoperative compared with postoperative radiation therapy (RT) in children with neuromuscular hip dysplasia (NHD) following proximal femoral resection (PFR).

Methods

A retrospective, 2-institution chart review was performed. Eligibility was limited to patients with at least 1 year of follow-up. Evaluation included radiographic HO grading by a combined severity scale, assessment of synchronous symptoms of pain or decreased range of motion, and stratification by preoperative versus postoperative reception of RT. A control cohort included 4 nonirradiated hips with NHD after PFR.

Results

Twenty-five hips in 20 children met eligibility criteria. Eleven hips were irradiated preoperatively and 14 postoperatively. Radiographic evidence of post-RT development of radiographic evidence of heterotopic ossification (rHO) was found in all 25 hips and earlier in patients irradiated preoperatively (median time to rHO was 4.0 vs. 15.7 mo, P=0.03, 95% confidence interval, 0.24-21.5). There was no statistically significant difference in the development of symptomatic HO (P=0.62) between the preoperative (45.5%) and postoperative (35.7%) groups, nor in HO grade (P=0.34). Seven (28%) of the 25 hips (5 preoperative and 2 postoperative) had documentation of rHO-free intervals after surgery, with an average duration of 5.6 months, while the remaining presented with rHO at first follow-up visit. All eligible control hips (100%) developed rHO and symptomatic heterotopic ossification.

Conclusions

Perioperative RT did not prevent the formation of HO in any child with NHD after PFR. Extrapolation of evidence of the efficacy of RT for HO prevention in ambulatory adults after traumatic hip injury to a population of children with central nervous system injury and NHD may be premature. Additional studies are needed to clarify optimal prevention of HO in this population.

Level of evidence

Level III-therapeutic retrospective comparative study.

Intussusception is relatively uncommon, occurring in 0.5 to 2.3 cases per 1,000 live births in the USA. Radiology residents, therefore, have few opportunities to participate in intussusception reduction during training, and practicing radiologists encounter it infrequently. Training is essential, as successful reduction avoids surgery. The judgment involved in reducing an intussusception is best gained with experience. We developed a training device that simulates fluoroscopic intussusception reduction with air. The device consists of a doll that contains a cylinder with similar stress and strain characteristics to the human colon. The trainee pumps air into the cylinder through a rectal tube using a standard hand-held air reduction pump. A sensor measures the pressure within the chamber and transmits readings to a computer, which displays images from actual intussusception reductions based on the pressure maintained within the device. A random component in the software gives the user a new experience each time and models uncertainties in the actual reduction process, including perforation. This intussusception reduction simulator can enhance resident education, giving residents the opportunity to practice this technique before employing it on a real patient. The simulator can also help practicing radiologists become more comfortable with intussusception air reduction.

Introduction

Diagnosis of infantile thiamine deficiency disorders (TDD) is challenging due to the non-specific, highly variable clinical presentation, often leading to misdiagnosis. Our primary objective is to develop a case definition for thiamine responsive disorders (TRD) to determine among hospitalised infants and young children, which clinical features and risk factors identify those who respond positively to thiamine administration.

Methods and analysis

This prospective study will enrol 662 children (aged 21 days to <18 months) seeking treatment for TDD symptoms. Children will be treated with intravenous or intramuscular thiamine (100 mg daily for a minimum of 3 days) alongside other interventions deemed appropriate. Baseline assessments, prior to thiamine administration, include a physical examination, echocardiogram and venous blood draw for the determination of thiamine biomarkers. Follow-up assessments include physical examinations (after 4, 8, 12, 24, 36, 48 and 72 hours), echocardiogram (after 24 and 48 hours) and one cranial ultrasound. During the hospital stay, maternal blood and breast-milk samples and diet, health, anthropometric and socio-demographic information will be collected for mother-child pairs. Using these data, a panel of expert paediatricians will determine TRD status for use as the dependent variable in logistic regression models. Models identifying predictors of TRD will be developed and validated for various scenarios. Clinical prediction model performance will be quantified by empirical area under the receiver operating characteristic curve, using resampling cross validation. A frequency-matched community-based cohort of mother-child pairs (n=265) will serve as comparison group for evaluation of potential risk factors for TRD.

Ethics and dissemination

Ethical approval has been obtained from The National Ethics Committee for Health Research, Ministry of Health, Lao PDR and the Institutional Review Board of the University of California Davis. The results will be disseminated via scientific articles, presentations and workshops with representatives of the Ministry of Health.

Trial registration number

NCT03626337.

OBJECTIVE: To develop a predictive model for thiamine responsive disorders (TRDs) among infants and young children hospitalized with signs or symptoms suggestive of thiamine deficiency disorders (TDDs) based on response to therapeutic thiamine in a high-risk setting. STUDY DESIGN: Children aged 21 days to <18 months hospitalized with signs or symptoms suggestive of TDD in northern Lao Peoples Democratic Republic were treated with parenteral thiamine (100 mg daily) for ≥3 days in addition to routine care. Physical examinations and recovery assessments were conducted frequently for 72 hours after thiamine was initiated. Individual case reports were independently reviewed by three pediatricians who assigned a TRD status (TRD or non-TRD), which served as the dependent variable in logistic regression models to identify predictors of TRD. Model performance was quantified by empirical area under the receiver operating characteristic curve. RESULTS: A total of 449 children (median [Q1, Q3] 2.9 [1.7, 5.7] months old; 70.3% exclusively/predominantly breastfed) were enrolled; 60.8% had a TRD. Among 52 candidate variables, those most predictive of TRD were exclusive/predominant breastfeeding, hoarse voice/loss of voice, cyanosis, no eye contact, and no diarrhea in the previous 2 weeks. The area under the receiver operating characteristic curve (95% CI) was 0.82 (0.78, 0.86). CONCLUSIONS: In this study, the majority of children with signs or symptoms of TDD responded favorably to thiamine. While five specific features were predictive of TRD, the high prevalence of TRD suggests that thiamine should be administered to all infants and children presenting with any signs or symptoms consistent with TDD in similar high-risk settings. The usefulness of the predictive model in other contexts warrants further exploration and refinement. TRIAL REGISTRATION: Clinicaltrials.gov NCT03626337.