A pilot longitudinal study of hippocampal volumes in pediatric maltreatment-related posttraumatic stress disorder.

BACKGROUND: Adult posttraumatic stress disorder (PTSD) is associated with decreased hippocampal volumes; however, decreased hippocampal volumes were not seen in pediatric maltreatment-related PTSD. We examined hippocampal volumes longitudinally to determine if a history of childhood traumatic stress alters hippocampal growth during puberty. METHODS: Magnetic resonance imaging was used to measure temporal lobes, amygdala, and hippocampal volumes in nine prepubertal maltreated subjects with pediatric maltreatment-related PTSD and nine sociodemographically matched healthy nonmaltreated yoked control subjects at baseline and after at least 2 years follow-up (during the later stages of pubertal development) using identical equipment and measurement methodology. RESULTS: Temporal lobe, amygdala and hippocampal volumes did not differ between groups at baseline, follow-up, or across time. CONCLUSIONS: Whereas these data are from a small sample, the results do not support hippocampal changes in pediatric maltreatment-related PTSD.

Sex differences in brain maturation during childhood and adolescence.

Brain development during childhood and adolescence is characterized by both progressive myelination and regressive pruning processes. However, sex differences in brain maturation remain poorly understood. Magnetic resonance imaging was used to examine the relationships between age and sex with cerebral gray and white matter volumes and corpus callosal areas in 118 healthy children and adolescents (61 males and 57 females), aged 6-17 years. Gender groups were similar on measures of age, handedness, socioeconomic status and Full Scale IQ. Significant age-related reductions in cerebral gray and increases in white matter volumes and corpus callosal areas were evident, while intracranial and cerebral volumes did not change significantly. Significant sex by age interactions were seen for cerebral gray and white matter volumes and corpus callosal areas. Specifically, males had more prominent age-related gray matter decreases and white matter volume and corpus callosal area increases compared with females. While these data are from a cross-sectional sample and need to be replicated in a longitudinal study, the findings suggest that there are age-related sex differences in brain maturational processes. The study of age-related sex differences in cerebral pruning and myelination may aid in understanding the mechanism of several developmental neuropsychiatric disorders.

A pilot study of amygdala volumes in pediatric generalized anxiety disorder.

BACKGROUND: The neurodevelopment of childhood anxiety disorders is not well understood. Basic research has implicated the amygdala and circuits related to these nuclei as being central to several aspects of fear and fear-related behaviors in animals. METHODS: Magnetic resonance imaging was used to measure amygdala volumes and comparison brain regions in 12 child and adolescent subjects with generalized anxiety disorder and 24 comparison subjects. Groups were matched on age, sex, height, and handedness and were also similar on measures of weight, socioeconomic status, and full scale IQ. RESULTS: Right and total amygdala volumes were significantly larger in generalized anxiety disorder subjects. Intracranial, cerebral, cerebral gray and white matter, temporal lobe, hippocampal, and basal ganglia volumes and measures of the midsagittal area of the corpus callosum did not differ between groups. CONCLUSIONS: Although these data are preliminary and from a small sample, the results are consistent with a line of thinking that alterations in the structure and function of the amygdala may be associated with pediatric generalized anxiety disorder.

A.E. Bennett Research Award. Developmental traumatology. Part II: Brain development.

BACKGROUND: Previous investigations suggest that maltreated children with a diagnosis of posttraumatic stress disorder (PTSD) evidence alterations of biological stress systems. Increased levels of catecholaminergic neurotransmitters and steroid hormones during traumatic experiences in childhood could conceivably adversely affect brain development. METHODS: In this study, 44 maltreated children and adolescents with PTSD and 61 matched controls underwent comprehensive psychiatric and neuropsychological assessments and an anatomical magnetic resonance imaging (MRI) brain scan. RESULTS: PTSD subjects had smaller intracranial and cerebral volumes than matched controls. The total midsagittal area of corpus callosum and middle and posterior regions remained smaller; while right, left, and total lateral ventricles were proportionally larger than controls, after adjustment for intracranial volume. Brain volume robustly and positively correlated with age of onset of PTSD trauma and negatively correlated with duration of abuse. Symptoms of intrusive thoughts, avoidance, hyperarousal or dissociation correlated positively with ventricular volume, and negatively with brain volume and total corpus callosum and regional measures. Significant gender by diagnosis effect revealed greater corpus callosum area reduction in maltreated males with PTSD and a trend for greater cerebral volume reduction than maltreated females with PTSD. The predicted decrease in hippocampal volume seen in adult PTSD was not seen in these subjects. CONCLUSIONS: These data suggest that the overwhelming stress of maltreatment experiences in childhood is associated with adverse brain development.