The current role of diagnostic imaging in the preoperative workup for refractory neonatal brachial plexus palsy.

INTRODUCTION: Despite recent improvements in perinatal care, the incidence of neonatal brachial plexus palsy (NBPP) remains relatively common. CT myelography is currently considered to be the optimal imaging modality for evaluating nerve root integrity. Recent improvements in MRI techniques have made it an attractive alternative to evaluate nerve root avulsions (preganglionic injuries). AIM: We demonstrate the utility of MRI for the evaluation of normal and avulsed spinal nerve roots. We also show the utility of ultrasound in providing useful preoperative evaluation of the postganglionic brachial plexus in patients with NBPP.

Utility of ultrasound in noninvasive preoperative workup of neonatal brachial plexus palsy.

BACKGROUND: Ultrasound has been utilized in the evaluation of compressive and traumatic peripheral nerve pathology. OBJECTIVE: To determine whether US can provide comprehensive evaluation of the post-ganglionic brachial plexus in the setting of neonatal brachial plexus palsy and whether this information can be used to guide preoperative nerve reconstruction strategies. MATERIALS AND METHODS: In this retrospective cohort study, preoperative brachial plexus ultrasonography was performed in 52 children with neonatal brachial plexus palsy who were being considered for surgery. The 33 children who had surgery compose the patient cohort. The presence and location of post-ganglionic neuromas were evaluated by US and compared to the surgical findings. US evaluation of shoulder muscle atrophy was conducted as an indirect way to assess the integrity of nerves. Finally, we correlated glenohumeral joint laxity to surgical and clinical management. RESULTS: Ultrasound correctly identified 21 of 25 cases of upper trunk and middle trunk neuroma involvement (84% sensitivity for each). It was 68% sensitive and 40% specific in detection of lower trunk involvement. US identified shoulder muscle atrophy in 11 of 21 children evaluated; 8 of these 11 went on to nerve transfer procedures based upon the imaging findings. US identified 3 cases of shoulder joint laxity of the 13 children evaluated. All 3 cases were referred for orthopedic evaluation, with 1 child undergoing shoulder surgery and another requiring casting. CONCLUSION: Ultrasound can provide useful preoperative evaluation of the post-ganglionic brachial plexus in children with neonatal brachial plexus palsy.

Repeatability of diagnostic features and scoring systems for hepatocellular carcinoma by using MR imaging.

PURPOSE: To determine for expert and novice radiologists repeatability of major diagnostic features and scoring systems (ie, Liver Imaging Reporting and Data System [LI-RADS], Organ Procurement and Transplantation Network [OPTN], and American Association for the Study of Liver Diseases [AASLD]) for hepatocellular carcinoma (HCC) by using magnetic resonance (MR) imaging. MATERIALS AND METHODS: Institutional review board approval was obtained and patient consent was waived for this HIPAA-compliant, retrospective study. The LI-RADS discussed in this article refers to version 2013.1. Ten blinded readers reviewed 100 liver MR imaging studies that demonstrated observations preliminarily assigned LI-RADS scores of LR1-LR5. Diameter and major HCC features (arterial hyperenhancement, washout appearance, pseudocapsule) were recorded for each observation. LI-RADS, OPTN, and AASLD scores were assigned. Interreader agreement was assessed by using intraclass correlation coefficients and κ statistics. Scoring rates were compared by using McNemar test. RESULTS: Overall interreader agreement was substantial for arterial hyperenhancement (0.67 [95% confidence interval {CI}: 0.65, 0.69]), moderate for washout appearance (0.48 [95%CI: 0.46, 0.50]), moderate for pseudocapsule (0.52 [95% CI: 050, 0.54]), fair for LI-RADS (0.35 [95% CI: 0.34, 0.37]), fair for AASLD (0.39 [95% CI: 0.37, 0.42]), and moderate for OPTN (0.53 [95% CI: 0.51, 0.56]). Agreement for measured diameter was almost perfect (range, 0.95-0.97). There was substantial agreement for most scores consistent with HCC. Experts agreed significantly more than did novices and were significantly more likely than were novices to assign a diagnosis of HCC (P < .001). CONCLUSION: Two of three major features for HCC (washout appearance and pseudocapsule) have only moderate interreader agreement. Experts and novices who assigned scores consistent with HCC had substantial but not perfect agreement. Expert agreement is substantial for OPTN, but moderate for LI-RADS and AASLD. Novices were less consistent and less likely to diagnose HCC than were experts.

Effect of intravenous low-osmolality iodinated contrast media on patients with myasthenia gravis.

PURPOSE: To determine whether the intravenous administration of low-osmolality contrast material is associated with exacerbation of disease-related symptoms in patients with myasthenia gravis. MATERIALS AND METHODS: This HIPAA-compliant, retrospective cohort study was approved by the institutional review board. The requirement to obtain patient consent was waived. Computed tomography (CT) was performed in 267 patients with clinically confirmed myasthenia gravis between January 1, 1995, and December 31, 2011. CT was performed without intravenous administration of contrast material in 155 patients and with intravenous administration of low-osmolality contrast material in 112. Electronic medical records were searched to identify myasthenia gravis-related symptoms before (≤ 14 days) and after (≤ 45 days) each CT examination. The Mantel-Cox log-rank test was used to compare the time to symptom progression between the two groups. The Fisher exact test was used to compare rates of disease-related symptoms during three time periods: (a) 0-1 day after CT, (b) 2-7 days after CT, and (c) 8-45 days after CT. RESULTS: The unenhanced and contrast-enhanced CT groups had similar thymectomy rates (P = .97) and disease-related symptom trends before CT (P = .58). The contrast-enhanced CT group was associated with a significant reduction in time to disease-related symptom progression following CT (median time to onset of symptom progression, 2.5 days with contrast-enhanced CT vs 14.0 days with unenhanced CT; P = .05). There were significantly more disease-related symptom exacerbations within 1 day of CT in the contrast-enhanced CT group compared with the unenhanced CT group (6.3% [seven of 112 patients] vs 0.6% [one of 155 patients], respectively; P = .01). Acute exacerbations were primarily respiratory (five patients with new-onset dyspnea [four in contrast-enhanced CT group and one in unenhanced CT group], two patients with progressive dyspnea [both in the contrast-enhanced CT group], and one patient with progressive weakness [in contrast-enhanced CT group]). There was no difference in symptoms between groups at 2-7 days (P = .70) or 8-45 days (P = .99). CONCLUSION: Intravenous administration of low-osmolality contrast material is significantly associated with exacerbation of myasthenia gravis-related symptoms. Exacerbations most commonly manifest as new or progressive acute respiratory compromise.

Ultrasonography for neonatal brachial plexus palsy.

Ultrasonography has previously been reported for use in the evaluation of compressive or traumatic peripheral nerve pathology and for its utility in preoperative mapping. However, these studies were not performed in infants, and they were not focused on the brachial plexus. The authors report a case in which ultrasonography was used to improve operative management of neonatal brachial plexus palsy (NBPP). An infant boy was born at term, complicated by right-sided shoulder dystocia. Initial clinical evaluation revealed proximal arm weakness consistent with an upper trunk injury. Unlike MRI or CT myelography that focus on proximal nerve roots, ultrasonography of the brachial plexus in the supraclavicular fossa was able to demonstrate a small neuroma involving the upper trunk (C-5 and C-6) and no asymmetry in movement of the diaphragm or in the appearance of the rhomboid muscle when compared with the unaffected side. However, the supra- and infraspinatus muscles were significantly asymmetrical and atrophied on the affected side. Importantly, ultrasound examination of the shoulder revealed posterior glenohumeral laxity. Instead of pursuing the primary nerve reconstruction first, timely treatment of the shoulder subluxation prevented formation of joint dysplasia and formation of a false glenoid, which is a common sequela of this condition. Because the muscles innervated by proximal branches of the cervical nerve roots/trunks were radiographically normal, subsequent nerve transfers were performed and good functional results were achieved. The authors believe this to be the first report describing the utility of ultrasonography in the surgical treatment planning in a case of NBPP. Noninvasive imaging, in addition to thorough history and physical examination, reduces the intraoperative time required to determine the extent and severity of nerve injury by allowing improved preoperative planning of the surgical strategy. Inclusion of ultrasonography as a preoperative modality may yield improved outcomes for children with NBPP.

Shorter sleep duration is associated with increased risk for being overweight at ages 9 to 12 years.

OBJECTIVE: The potential association between short sleep duration or sleep problems and childhood overweight has not been well described. The objective of this study was to test the independent associations of sleep duration and problems with overweight risk in children. METHODS: Data from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development were analyzed. In 3rd and 6th grades, sleep duration and problems were obtained by maternal report, and height and weight were measured, with overweight defined as a BMI of > or = 95th percentile for age and gender. Logistic regression evaluated the association of sleep duration and problems with overweight at 6th grade cross-sectionally adjusting for gender, race, and maternal education. Additional covariates tested individually included the level of chaos at home, the quality of the home environment, the lax-parenting subscale score of the Raising Children Checklist, and the Child Behavior Checklist internalizing and externalizing subscale scores. Logistic regression also evaluated the relationship of sleep duration at 3rd grade and overweight at 6th grade, adjusting for gender, race, maternal education, and the child's BMI z score in 3rd grade. RESULTS: Of 785 children, 50% were male, 81% were white, and 18% were overweight in 6th grade. Shorter sleep duration in 6th grade was independently associated with a greater likelihood of overweight in 6th grade. Shorter sleep duration in 3rd grade was also independently associated with overweight in 6th grade, independent of the child's weight status in 3rd grade. Sleep problems were not associated with overweight. CONCLUSION: One preventive approach to overweight may be to ensure adequate sleep in childhood.