Abnormal Frontal Gyrus, Limbic Activity Observed During Attentional Activity in Pediatric Bipolar Disorder

According to results of a meta-analysis published in Progress in Neuropsychopharmacology & Biological Psychiatry, abnormal fronto-striatal and fronto-limbic circuitries are present in pediatric bipolar disorder while probing the attentional systems. However, these abnormalities do not appear to persist into adulthood, indicating a differential pattern in pediatric and adult bipolar disorders.

Researchers used literature databases to retrieve functional magnetic resonance imaging (fMRI) studies of pediatric bipolar disorder (PBD) or adult bipolar disorder (ABD). Each study had a control group of age-matched healthy volunteers. A total of 10 pediatric studies and 9 adult patient studies were extracted and included in a meta-analysis on the attention domain in patients with bipolar disorder. Researchers employed an activation likelihood estimation technique for analysis, which evaluates the consistency of activation in any given set of studies. 

The PBD group demonstrated decreased activation in the anterior cingulate cortex and in limbic regions while paying attention in comparison with typically developing patients. In addition, increased activation was observed in the frontal gyrus in patients with PBD during attentional tasks, compared with typically developing controls. Patterns of decreased activity relative to control patients were also observed in the dorsolateral prefrontal cortex, the right lentiform nucleus, and the right globus pallidus in patients with PBD. However, these discrepancies did not seem to persist into adulthood, with no significant activation differences between adult patients with bipolar disorder and healthy adult patients during attentional activities.

Researchers noted that attention response is difficult to isolate as it recruits multiple brain circuits. Still, these results indicate that PBD and ABD demonstrate differential activation patterns, which may be helpful in elucidating the specific brain mechanisms of bipolar disorder during cognitive development, as well as the association between emotional dysregulation and attentional systems.

Reference

Lee M-S, Anumagalla P, Talluri P, Pavuluri MN. Attentional engagement increases inferior frontal gyrus activity and mutes limbic activity in pediatric bipolar disorder: meta-analyses of fMRI studies [published online May 19, 2018]. Prog Neuropsychopharmacol Biol Psychiatry. doi:10.1016/j.pnpbp.2018.05.011