Cognition and dorsolateral prefrontal cortex volume in corticosteroid‐treated patients given lamotrigine

Abstract

In addition to changes in declarative memory and the hippocampus, corticosteroid excess is associated with prefrontal cortex changes. We previously reported that patients receiving exogenous corticosteroid therapy had impaired performance on prefrontal cortex‐related tasks, including working memory and executive functioning tasks. Glutamate release inhibitors attenuate corticosteroid‐effects on the hippocampus in both animal and human models. Twenty‐eight outpatients receiving chronic prednisone therapy for transplant rejection or other medical conditions were randomized to lamotrigine (a glutamate release inhibitor) or placebo for 24 weeks. Dorsolateral prefrontal cortex (DLPFC) volume was manually traced from MRI scans by trained staff members. Cognition was examined using the Stroop Color Word Test (SCWT), Delis‐Kaplan Executive Function System (D‐KEFS) and the Trail Making Test. Groups were compared using analysis of covariance. Consistent with prior findings in corticosteroid‐treated patients, baseline cognitive function was in the low normal range. At baseline, prednisone duration showed a trend towards negative correlation with SCWT and D‐KEFS inhibition switching time error scores, and DLPFC volume showed a trend towards a positive correlation with SCWT scores. No significant between‐group differences in outcomes were observed following lamotrigine therapy. Thus, this study found lamotrigine to not be associated with either positive or negative effects on cognition or DLPFC volume. Copyright © 2010 John Wiley & Sons, Ltd.

Does traditional asian vegetables (ulam) consumption correlate with brain activity using fMRI? A study among aging adults from low‐income households

“…Since the left DLPFC had been selectively activated during the high conflict of the SCWT trials, 35 this had thus demonstrated a higher left DLPFC activation through the coordinated recruitment of brain systems and, consequently, a higher cognitive skill was observed among the subjects with higher ulam consumption. 36 Although the right DLPFC activation had not been significantly associated with ulam consumption, its activation could have been due to the macro-adjustments of the cognitive control, which minimized the subsequent attentional conflict during the frequent congruent and incongruent SCWT. 23 The sample size of this study was also calculated and justified sufficiently, where the investigation on the association between ulam consumption and brain activation had been successfully conducted through the use of the fMRI; hence, corresponding to several previous studies that were conducted on the nutrients intake and brain activation with a small sample (n = 15-30).…”

“…The latest evidence therefore reported the left hemisphere of the human brain as being more affected by the interference than the right hemisphere when naming the color of a word that conflicted with the displayed word (eg, the word "yellow" printed in "orange"). Since the left DLPFC had been selectively activated during the high conflict of the SCWT trials, this had thus demonstrated a higher left DLPFC activation through the coordinated recruitment of brain systems and, consequently, a higher cognitive skill was observed among the subjects with higher ulam consumption . Although the right DLPFC activation had not been significantly associated with ulam consumption, its activation could have been due to the macro‐adjustments of the cognitive control, which minimized the subsequent attentional conflict during the frequent congruent and incongruent SCWT …”