Correlação entre espessura cortical frontal e desempenho de funções executivas em pacientes com infecção pelo vírus da imunodeficiência humana

The association of peripheral immune markers with brain cortical thickness and surface area in South African people living with HIV

A spectrum of cognitive impairments known as HIV-associated neurocognitive disorders (HAND) are consequences of the effects of HIV-1 within the central nervous system. Regardless of treatment status, an aberrant chronic neuro-immune regulation is a crucial contributor to the development of HAND. However, the extent to which inflammation affects brain structures critical for cognitive status remains unclear. The present study aimed to determine associations of peripheral immune markers with cortical thickness and surface area. Participants included 65 treatment-naïve HIV-positive individuals and 26 HIV-negative controls. Thickness and surface area of all cortical regions were derived using automated parcellation of T1-weighted images acquired at 3 T. Peripheral immune markers included C-C motif ligand 2 (CCL2), matrix metalloproteinase 9 (MMP9), neutrophil gelatinase-associated lipocalin (NGAL), thymidine phosphorylase (TYMP), transforming growth factor (TGF)-β1, and vascular endothelial growth factor (VEGF), which were measured using enzyme-linked immunosorbent assays. Associations of these markers with thickness and surface area of cortical regions were evaluated. A mediation analysis examined whether associations of inflammatory markers with cognitive functioning were mediated by brain cortical thickness and surface area. After controlling for multiple comparisons, higher NGAL was associated with reduced thickness of the bilateral orbitofrontal cortex in HIV-positive participants. The association of NGAL with worse motor function was mediated by cortical thickness of the bilateral orbitofrontal region. Taken together, this study suggests that NGAL plays a potential role in the neuropathophysiology of neurocognitive impairments of HIV.

Clinical and Cognitive Correlates of Insight in Bipolar Disorder

Insight is greatly impaired in Bipolar Disorder (BD), especially during mania. Cognitive impairment is also present in BD. Despite that, few studies have investigated a possible association between these two aspects. The main goal of the current study is to compare BD affective states regarding performance in cognitive testing and investigate clinical and cognitive predictors for insight loss in BD. The study investigated a sample of 65 patients who were evaluated in one of the BD phases (mania, euthymia or depression). All the subjects underwent neuropsychological evaluation and completed the Insight Scale for Affective Disorders (ISAD). The relationship between level of insight and clinical/cognitive variables was analyzed through multiple regression models. No significant differences were found among BD phases regarding performance on cognitive testing. Insight was more impaired in mania then in depression or euthymia. Predictors for loss of insight were: severity of manic symptoms and impairments in selective attention (Symbol search test), divided attention (Trail making test) and inhibition (Stroop test). The sample size is a potential limitation of the current study. Nevertheless, the results suggest this had limited impact, with group differences being detected for a number of variables. The results found have important clinical importance, suggesting, for example, that rehabilitation of specific cognitive skills may improve insight in BD.