Sub-graph entropy based network approaches for classifying adolescent obsessive-compulsive disorder from resting-state functional MRI

• Published in: NeuroImage clinical Vol. 26; p. 102208
• Main Authors: Sen, Bhaskar, Bernstein, Gail A., Mueller, Bryon A., Cullen, Kathryn R., Parhi, Keshab K.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.01.2020; Elsevier
• Subjects: Adolescent; Classification; Entropy; Female; Functional network; Humans; Image Interpretation, Computer-Assisted - methods; Magnetic Resonance Imaging - methods; Male; Nerve Net - diagnostic imaging; Nerve Net - physiopathology; Neural Pathways - diagnostic imaging; Neural Pathways - physiopathology; Neuroimaging - methods; Obsessive compulsive disorder; Obsessive-Compulsive Disorder - classification; Obsessive-Compulsive Disorder - diagnostic imaging; Obsessive-Compulsive Disorder - physiopathology; Psychiatry; Regular; Sub-graph entropy; Sub-graph entropy; Obsessive compulsive disorder; Psychiatry; Functional network; Classification
• ISSN: 2213-1582; 2213-1582
• DOI: 10.1016/j.nicl.2020.102208

•The proposed classification scheme improves the best-known adolescent OCD vs. healthy controls classification accuracy from 78% to 89%.•This paper validates the efficacy of sub-graph entropy for classifying OCD vs. healthy groups.•The proposed technique identifies a predictive sub-network that partially consists of regions from well-known cortico-striato-thalamic-cortical (CSTC) network.•For both predictive sub-network and CSTC sub-network, sub-graph entropy is significantly lower in OCD patients compared with healthy controls.•Sub-graph entropy using 1-hop neighborhood is effective in the classification task. Sub-graph entropy using 2-hop neighborhood has a lower classification accuracy. This paper presents a novel approach for classifying obsessive-compulsive disorder (OCD) in adolescents from resting-state fMRI data. Currently, the state-of-the-art for diagnosing OCD in youth involves interviews with adolescent patients and their parents by an experienced clinician, symptom rating scales based on Diagnostic and Statistical Manual of Mental Disorders (DSM), and behavioral observation. Discovering signal processing and network-based biomarkers from functional magnetic resonance imaging (fMRI) scans of patients has the potential to assist clinicians in their diagnostic assessments of adolescents suffering from OCD. This paper investigates the clinical diagnostic utility of a set of univariate, bivariate and multivariate features extracted from resting-state fMRI using an information-theoretic approach in 15 adolescents with OCD and 13 matched healthy controls. Results indicate that an information-theoretic approach based on sub-graph entropy is capable of classifying OCD vs. healthy subjects with high accuracy. Mean time-series were extracted from 85 brain regions and were used to calculate Shannon wavelet entropy, Pearson correlation matrix, network features and sub-graph entropy. In addition, two special cases of sub-graph entropy, namely node and edge entropy, were investigated to identify important brain regions and edges from OCD patients. A leave-one-out cross-validation method was used for the final predictor performance. The proposed methodology using differential sub-graph (edge) entropy achieved an accuracy of 0.89 with specificity 1 and sensitivity 0.80 using leave-one-out cross-validation with in-fold feature ranking and selection. The high classification accuracy indicates the predictive power of the sub-network as well as edge entropy metric.