<p>Resting-state functional magnetic resonance imaging (fMRI) and functional connectivity density mapping in patients with corneal ulcer</p>

Abstract

Purpose To investigate alternations in spontaneous brain activities reflected by functional connectivity density (FCD) in patients with corneal ulcer (CU) using resting-state functional connectivity (rsFC). Methods We recruited 24 patients with CU (12 males, 12 females), and 24 healthy controls (HCs; 12 males, 12 females) matched for age, gender and education status. Functional magnetic resonance imaging examinations were performed on all subjects in a resting state and the following parameters determined: rsFC, long-range FCD (longFCD) and short-range FCD (IFCD). Receiver operating characteristic (ROC) curves were then used to differentiate patients with CU from HCs. Results Compared with HCs, CU patients showed significantly reduced rsFC values in the right cerebellum posterior lobe gyrus, right middle frontal gyrus/inferior frontal gyrus/superior frontal gyrus and left inferior parietal lobule/precuneus. Significantly reduced longFCD values were found in the right hippocampus/inferior temporal gyrus and the left inferior temporal gyrus. Moreover, compared with HCs, IFCD values were significantly reduced in the left inferior temporal gyrus/middle temporal gyrus, left limbic lobe/medial frontal gyrus, and left precuneus/limbic lobe, but were significantly increased in the right insula/superior temporal gyrus, left superior temporal gyrus/inferior frontal gyrus/insula, right superior temporal gyrus/postcentral gyrus, and left precentral gyrus. Conclusions Patients with CU exhibited alterations in spontaneous brain activities in several brain areas. These novel findings may help to reveal the neuropathological mechanisms underlying CU. This study provides a direction for further exploration of underlying neural mechanisms of CU and facilitate the clinical diagnosis and treatment of CU.

Altered Long- and Short-Range Functional Connectivity Density in Patients With Thyroid-Associated Ophthalmopathy: A Resting-State fMRI Study

“…FCD is divided into long-range and short-range FCDs, reflecting interregional and intraregional functional interactions, respectively. Previously, the method has already been applied in several ocular diseases, such as glaucoma ( 17 ), neuromyelitis optica ( 16 ), corneal ulcer ( 18 ), and eye pain ( 19 ), to explore changes in global and local functional connectivity of the brain. Hence, we hypothesized that the underlying alterations of interregional and intraregional functional interactions in the TAO cohort could also be visualized by long- and short-range FCDs, which may be a supplement to the functional neural mechanism of TAO.…”

Voxel-based morphometry reveals altered gray matter volume related to cognitive dysfunctioning in neovascular glaucoma patients

“…It is concerned with recognition and judgement based on spatial information about objects and simultaneously plays an important role in optic nerve positioning, multi-retina correspondence, and the formation of scotoma of the fixation point [37]. The frontal gyrus includes superior, medial and inferior frontal gyrus, and abnormalities of its structure or function have been investigated in many ophthalmic diseases, including but not limited to diabetic retinopathy [38], strabismus with amblyopia [39], corneal ulcer [40] and ophthalmectomy [14]. In this study, we found that VBM results indicated significant GMV reduction in all of these regions (medial, superior, and inferior frontal gyrus), which are the same as Wang et al [41] and it may be related to increased intraocular pressure (IOP).…”

Bayesian variable selection in logistic regression with application to whole-brain functional connectivity analysis for Parkinson’s disease

“…Resting-state functional connectivity analysis is an effective method for estimating spontaneous functional activity and measuring the temporal correlation between spatially remote neurophysiological events. 50 The preprocessed rs-fMRI images were further segmented into 112 regions of interest (ROI) with reference to the Harvard-Oxford atlas (HOA) using the Resting-State fMRI Data Analysis Toolkit (REST, http://restfmri.net/). Functional connectivity is defined as the temporal correlations between spatially remote neurophysiological events and a dynamic functional brain connectivity time series is usually created by estimating the connectivity (most often Pearson correlation coefficients) for multiple time points across two nodes (often voxels or ROIs).…”