# Abnormal spontaneous regional white-matter brain activity in patients with obsessive-compulsive disorder

## TL;DR

This study found abnormal brain activity in white matter regions of people with obsessive-compulsive disorder, which may explain their cognitive inflexibility.

## Contribution

The study is the first to investigate spontaneous white-matter neural activity in OCD using resting-state fMRI.

## Key findings

- OCD patients showed higher ReHo in the left posterior limb of the internal capsule and right superior corona radiata.
- OCD patients showed lower ALFF in the right superior longitudinal fasciculus and right cerebral peduncle.
- No correlation was found between clinical symptoms and abnormal ALFF or ReHo values in OCD patients.

## Abstract

Previous studies on white matter (WM) in patients with obsessive-compulsive disorder (OCD) have focused primarily on its structural aspects. This study aimed to investigate any abnormal spontaneous WM neural activity in patients with OCD.

The study was based on resting-state functional magnetic resonance imaging (fMRI) data from 27 patients with OCD and 24 matched healthy controls (HC). Regional homogeneity (ReHo) and the amplitude of low-frequency fluctuation (ALFF) were used to explore spontaneous neural activity changes in the subjects’ WM regions. A two-sample Student’s t-test was performed, and correlations between the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), Hamilton Anxiety Scale (HAMA), and Hamilton Depression Scale (HAMD) scores were analyzed.

The ReHo in the left posterior limb of the internal capsule (LPLIC) and right superior corona radiata (RSCR) of the OCD group was significantly higher than those in the HCs (pTFCE–FWE < 0.001). The ALFFs in the right superior longitudinal fasciculus (RSLF) and right cerebral peduncle (RCP) of the OCD group, by contrast, were significantly lower than those in the HCs (pTFCE–FWE < 0.05). There was no correlation between the clinical symptoms of patients with OCD and their abnormal amplitude of low-frequency fluctuation (ALFF) and ReHo values.

Abnormal spontaneous WM activity was observed in several brain regions in patients with OCD. This activity may help explain the cognitive inflexibility often observed in this patient group.