Localized Connectivity in Obsessive-Compulsive Disorder: An Investigation Combining Univariate and Multivariate...

Area of Science:

• Neuroscience
• Psychiatry
• Radiology

Background:

• Obsessive-compulsive disorder (OCD) is associated with disrupted large-scale functional brain network organization.
• The impact of localized brain area activation abnormalities on network dysfunction in OCD requires further investigation.

Purpose of the Study:

• To investigate regional homogeneity (ReHo) abnormalities in medication-free OCD patients compared to healthy controls.
• To determine if ReHo can differentiate individuals with OCD from healthy controls.

Main Methods:

• Utilized univariate analysis and multivariate pattern analysis (MVPA) on resting-state functional magnetic resonance imaging (RS-fMRI) data.
• Analyzed ReHo, an index of localized connectivity, in 88 OCD patients and 88 healthy control subjects (HCS).
• Employed support vector machine (SVM) for individual-level classification.

Main Results:

• OCD patients exhibited lower ReHo in the bilateral cerebellum and higher ReHo in the bilateral superior frontal gyri (SFG), right inferior parietal gyrus (IPG), and precuneus compared to HCS.
• Left SFG ReHo positively correlated with Yale-Brown Obsessive Compulsive Scale (Y-BOCS) scores.
• SVM classification achieved 78.98% accuracy in differentiating OCD patients from HCS, with key discriminative regions including frontal, temporal, parietal areas, and the cerebellum.

Conclusions:

• Localized activation disequilibrium between the prefrontal cortex (PFC) and cerebellum is linked to OCD pathophysiology.
• ReHo patterns demonstrate potential as a discriminative biomarker for detecting OCD at the individual level.