Widespread cortical changes in pediatric bipolar disorder with psychosis
MedWire News: Children with bipolar disorder (BD) who also experience symptoms of psychosis show widespread cortical changes relative to their mentally healthy peers, research shows.
"Pediatric BD is a severe and persistent, cyclic mood disorder with an estimated prevalence of 1%. The disorder is thought to arise from dysfunction in neural networks subserving emotional processing and regulation and to involve frontolimbic, frontostriatal, and frontotemporal circuitries," observe Anthony James (Warneford Hospital, Oxford, UK) and team.
To identify neuropsychological and structural brain changes associated with pediatric BD with psychosis, the team recruited 15 children with the mood disorder who also suffered from delusions and/or hallucinations and 20 age- and gender-matched mentally healthy controls. All of the children with BD were euthymic at the time of recruitment.
"Although not typical of all pediatric BD, psychosis provides a marker of severity of PBD and characterizes a defined, potentially homogenous group of those with BD," explains the team.
All of the participants underwent high-resolution structural and diffusion tensor imaging of the brain, with voxel-based morphometry, tract-based spatial statistics, and probabilistic tractography used to analyze the data.
They also underwent a comprehensive neuropsychological test battery to assess various cognitive domains.
Compared with controls, patients with BD showed similar overall intelligence, but had specific deficits in working memory, executive function, language function, and verbal memory.
Regarding gray matter density, BD patients exhibited reductions in the left orbitofrontal cortex, left pars triangularis, right premotor cortex, occipital cortex, right occipital fusiform gyrus, and right crus of the cerebellum compared with controls.
Regarding white matter density, patients with BD had reduced fractional anisotropy in the anterior half of the corpus callosum relative to controls.
Regressional analysis showed that only verbal memory and working memory positively correlated with fractional anisotropy in BD patients.
Gray matter density, in contrast, was positively associated with all four cognitive domains: executive functioning, language, verbal memory, and working memory.
James and team conclude in the journal Bipolar Disorders: "The findings suggest widespread cortical changes as well as specific involvement of interhemispheric prefrontal tracts in pediatric BD, which may reflect delayed myelination in these tracts."
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By Mark Cowen