Striatal dysfunction during failed motor inhibition in children at risk for bipolar disorder
ABSTRACT A better understanding of the neural underpinnings of bipolar disorder (BD) can be obtained by examining brain activity in symptom-free individuals at risk for BD. This study examined the neural correlates of motor inhibition in a sample of symptom-free youths at familial risk for BD.
19 euthymic youths with BD, 13 asymptomatic youths with a first-degree relative with BD, and 21 healthy comparison children completed the stop signal task in a 3 T scanner.
Children at familial risk for BD exhibited increased putamen activation during unsuccessful inhibition that distinguished them from both healthy and BD children. Youths with BD exhibited reduced activation of the right nucleus accumbens during unsuccessful inhibition as compared to the other participant groups.
Striatal activation patterns differ between youths at risk for BD and healthy comparison children during a motor inhibition task.
SourceAvailable from: Mani N Pavuluri[Show abstract] [Hide abstract]
ABSTRACT: Objectives: Identifying early markers of brain function among those at high risk (HR) for pediatric bipolar disorder (PBD) could serve as a screening measure when children and ado-lescents present with subsyndromal clinical symptoms prior to the conversion to bipolar disorder. Studies on the offspring of patients with bipolar disorder who are genetically at HR have each been limited in establishing a biomarker, while an analytic review in summarizing the findings offers an improvised opportunity toward that goal. Methods: An activation likelihood estimation (ALE) meta-analysis of mixed cognitive and emotional activities using the GingerALE software from the BrainMap Project was com-pleted. The meta-analysis of all fMRI studies contained a total of 29 reports and included PBD, HR, and typically developing (TD) groups. Results:The HR group showed significantly greater activation relative to theTD group in the right DLPFC–insular–parietal–cerebellar regions. Similarly, the HR group exhibited greater activity in the right DLPFC and insula as well as the left cerebellum compared to patients with PBD. Patients with PBD, relative to TD, showed greater activation in regions of the right amygdala, parahippocampal gyrus, medial PFC, left ventral striatum, and cerebellum and lower activation in the right VLPFC and the DLPFC. Conclusion: The HR population showed increased activity, presumably indicating greater compensatory deployment, in relation to both the TD and the PBD, in the key cognition and emotion-processing regions, such as the DLPFC, insula, and parietal cortex. In con-trast, patients with PBD, relative to HR and TD, showed decreased activity, which could indicate a decreased effort in multiple PFC regions in addition to widespread subcortical abnormalities, which are suggestive of a more entrenched disease process.Frontiers in Psychiatry 03/2014; 5. DOI:10.3389/fpsyt.2014.00141
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ABSTRACT: Background Pediatric bipolar disorder (PBD) has attracted increasing attentions due to its high prevalence and great influence on social functions of children and adolescents. However, the pathophysiology underlying PBD remains unclear. In the present study, the resting-state functional magnetic resonance imaging (fMRI) was used to detect abnormalities of baseline brain functions in depressed PBD youth.Methods Seventeen youth with PBD-depression aged 10 - 18 years old and 18 age- and sex-matched normal controls were recruited in this study. The fMRI data under resting state were obtained on a Siemens 3.0 Tesla scanner and were analyzed using the regional homogeneity (ReHo) method. Correlations between the ReHo values of each survived area and the severity of depression symptoms in patients were further analyzed.ResultsAs compared with the control group, PBD-depression patients showed decreased ReHo in the medial frontal gyrus, bilateral middle frontal gyrus and middle temporal gyrus, and the right putamen. Significant negative correlations of the mood and feelings questionnaire scores with mean ReHo values in the medial frontal gyrus and the right middle frontal gyrus in PBD-depression patients were observed.Conclusion Our results suggest that extensive regions with altered baseline brain activities are existed in PBD-depression and these brain regions mainly locate in the fronto-limbic circuit and associated striatal structures. Moreover, the present findings also add to our understanding that there could be unique neuropathophysiological mechanisms underlying PBD-depression.BMC Psychiatry 08/2014; 14(1):222. DOI:10.1186/s12888-014-0222-y · 2.24 Impact Factor
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ABSTRACT: Background Pediatric bipolar disorder (PBD) has emerged as a field of research in which neuropsychological studies are continuously providing new empirical findings. Despite this, a comprehensive framework for neurocognitive impairments is still lacking, and most of the evidence remains unconnected. We addressed this question through a systematic review of neuropsychological research, with the aim of elucidating the main issues concerning this topic. Method A comprehensive search of databases (PubMed, PsycINFO) was performed. Published manuscripts between 1990 and January 2014 were identified. Overall, 124 studies fulfilled inclusion criteria. Methodological differences between studies required a descriptive review of findings. Results Evidence indicates that verbal/visual-spatial memory, processing speed, working memory, and social cognition are neurocognitive domains impaired in PBD youth. Furthermore, these deficits are greater among those who suffer acute affective symptoms, PBD type I, and/or attention deficit hyperactivity disorder (ADHD) comorbidity. In addition, several neurocognitive deficits imply certain changes in prefrontal cortex activity and are somewhat associated with psychosocial and academic disabilities. Strikingly, these deficits are consistently similar to those encountered in ADHD as well as severe mood dysregulation (SMD). Besides, some neurocognitive impairments appear before the onset of the illness and tend to maintain stable across adolescence. Finally, any therapy has not yet demonstrated to be effective on diminishing these neurocognitive impairments. Limitations More prolonged follow-up studies aimed at delineating the course of treatment and the response to it are warranted. Conclusions Despite noteworthy research on the neurocognitive profile of PBD, our knowledge is still lagging behind evidence from adult counterparts.Journal of Affective Disorders 09/2014; 166:297–306. DOI:10.1016/j.jad.2014.05.025 · 3.71 Impact Factor