ABSTRACT
Preterm neonates represent a high-risk population for abnormal neuropsychological development. But presently, an accurate method for identifying those at risk is not available. This study evaluated the association between the microstructural organization measured with Diffusion Tensor Imaging (DTI) in term-corrected preterm neonates and subsequent motor performance. Fractional anisotropy (FA), axial diffusion (AD), mean diffusivity (MD) and radial diffusivity (RD) were determined in two regions of interest (ROIs) corresponding to the posterior limb of the internal capsule (PLIC) and cortico-spinal tract (CST). The Griffiths Mental Developmental Scales (GMDS) were longitudinally administered at 3, 6 and 15 months; and correlations between the metrics of diffusivity and the motor subscale of the GMDS were assessed using the Spearman correlation. A statistically significant negative correlation was observed between the AD of PLIC of the left hemisphere and the 3-month GMDS Locomotor Subscale. These results suggested that AD is a valid indicator of the stage of maturation of the motor pathway in preterm neonates, but not of later motor outcome.
Subject(s)
Brain/pathology , Diffusion Tensor Imaging , Motor Disorders/diagnostic imaging , Motor Disorders/etiology , Premature Birth/diagnostic imaging , Premature Birth/physiopathology , Analysis of Variance , Anisotropy , Brain/growth & development , Female , Follow-Up Studies , Gestational Age , Humans , Infant , Infant, Newborn , Magnetic Resonance Imaging , Male , Statistics as TopicABSTRACT
Self-experience anomalies are elementary features of schizophrenic pathology. Such deficits can have a profound impact on self-other relationship, but how they are related through aberrant brain function remains poorly understood. In this functional magnetic resonance imaging (fMRI) study, we provide new evidence for a cortical link between aberrant self-experience and social cognition in first-episode schizophrenia (FES). As identified in previous studies, ventral premotor cortex (vPMC) and posterior insula (pIC) are candidate brain regions underlying disturbances in both self-experience and self-other relationship due to their processing of predominantly externally guided (vPMC; goal-oriented behavior) and internally guided (pIC; interoception) stimuli. Results from functional interaction analysis in a sample of 24 FES patients and 22 healthy controls show aberrant functional interactions (background/intrinsic connectivity) of right vPMC and bilateral pIC with posterior cingulate cortex (PCC), a midline region that has been shown central in mediating self-experience. More specifically, our results show increased functional coupling between vPMC and PCC, which positively correlated with basic symptoms (subjective self-experience disturbances). pIC showed reduced functional coupling with PCC and postcentral gyrus and increased functional interactions with anterior insula. Taken together, our results suggest an imbalance in the processing between internally and externally guided information and its abnormal integration with self-referential processing as mediated by PCC. Due to our correlation findings, we suggest this imbalance to be closely related to basic symptoms in FES and thus anomalous self-experience. The findings further disentangle the cortical basis of how self-experience anomalies may pervade the social domain.
