Discordance of prenatal and neonatal brain development in twins

pre-printBackground: Discordance of birth weight has been observed in twin pairs, though little is known about prenatal and early neonatal discordance of head and brain size, and the role that zygosity and chorionicity play in discordances of early brain development in twins. Aims: To compare prenatal and neonatal discordances of head size in monozygotic - monochorionic (MZ-MC), monozygotic-dichorionic (MZ-DC), and same-sex dizygoticdichorionic twin pairs (DZ-DC). Study Design: Subjects prospectively had ultrasounds at 22 and 32 weeks gestational age, and magnetic resonance imaging (MRI) of the brain MRI after birth. Subjects: 88 twin pairs recruited from two university hospital prenatal diagnostic clinics; 22 MZ-MC, 17 MZ-DC, and 49 same sex DZ-DC pairs. Outcome measures: Discordance of head circumference (HC) and weight at 22 weeks, 32 weeks and birth, as well as intracranial volume (ICV) on neonatal MRI. Results: There were no group differences in discordance of head circumference and weight on the 22 or 32 week ultrasounds, or at birth. MZ-MC twins tended to have numerically greater discordances of HC and weight. There was a significant group difference in ICV on neonatal MRI (ANOVA, p = 0.0143), with DZ-DC twins having significantly greater discordance than MZ-MC (p = 0.028) or MZ-DC (p = 0.0131) twins. Conclusions: This study indicates that zygosity and chorionicity do not contribute to significant discordances of head size in late prenatal development. DZ twins do have significantly greater discordances of ICV on neonatal MRI, suggesting a relatively greater genetic influence on brain growth in the first weeks after birth

Discordance of prenatal and neonatal brain development in twins

Discordance of birth weight has been observed in twin pairs, though little is known about prenatal and early neonatal discordance of head and brain size, and the role that zygosity and chorionicity play in discordances of early brain development in twins

Attitudes of dermatologists in the southeastern United States regarding treatment of alopecia areata: a cross-sectional survey study

<p>Abstract</p> <p>Background</p> <p>Little evidence exists to guide treatment of alopecia areata (AA). The current practices in treatment of children compared to adults and of progressive stages of hair loss are unknown. The objective of this study was to examine the current practices of southeastern United States dermatologists for the treatment of AA.</p> <p>Methods</p> <p>Dermatologists were sent anonymous questionnaires regarding their treatment practices by mail. Respondents' frequencies of treatment in children compared to adults and in patchy hair loss compared to widespread hair loss were compared with Wilcoxon signed-ranks tests and Friedman tests. As a secondary source, the National Alopecia Areata Registry (NAAR) database was analyzed for patients' treatment histories.</p> <p>Results</p> <p>Survey results suggested that dermatologists recommend treatment less frequently for children than adults and for more advanced hair loss. NAAR data confirmed that offering no treatment for AA is relatively common.</p> <p>Conclusion</p> <p>Dermatologists' treatment of AA is inconsistent. A stronger evidence base will provide more consistent treatment options.</p