Psychiatry Investig.  2023 Jun;20(6):550-558. 10.30773/pi.2022.0334.

Compromised Cerebello-Thalamic White Matter Integrity in Medication-Free Patients With Obsessive-Compulsive Disorder

• Lee W
• Park H
• Moon SY
• Oh S
• Lee J
• Kim M
• Kwon JS

• KMID: 2543113
• DOI: http://doi.org/10.30773/pi.2022.0334

Abstract

Objective
The cerebello-thalamic tract is the only efferent white matter (WM) bundle of the cerebellum that connects the cerebellum to the thalamus and has recently attracted much attention in obsessive-compulsive disorder (OCD) with its integral role in higher order cognitive functions commonly impaired in OCD patients. Previous neuroimaging studies have shown that the cerebello-thalamic circuit is functionally impaired in OCD patients. However, the WM integrity of the cerebello-thalamic tract in OCD, which may underly functional abnormalities of the cerebello-thalamic circuit, is not yet sufficiently understood. Therefore, the current study aimed to elucidate whether compromised cerebello-thalamic WM integrity is observed in medication-free OCD patients.
Methods
In this study, diffusion tensor imaging was acquired from 106 medication-free OCD patients and 105 matched healthy controls (HCs). Probabilistic tractography was then used to reconstruct the cerebello-thalamic tract with accurate anatomical features. Three diffusion indices (fractional anisotropy, FA; mean diffusivity, MD; radial diffusivity, RD) were measured from the reconstructed bilateral cerebello-thalamic tract and then compared between groups.
Results
We found that patients with OCD showed significantly increased MD and RD in the right cerebello-thalamic tract compared to HCs, and there was no difference in FA between groups.
Conclusion
Our findings may indicate the underlying structural abnormalities of the dysfunctional cerebello-thalamic circuit in OCD patients. Therefore, our findings are expected to provide novel insights into the pathophysiology of OCD on the cerebello-thalamic WM architecture, extending our knowledge from the existing functional neurobiological model of OCD.

Keyword

Cerebellum; Diffusion tensor imaging; Obsessive-compulsive disorder; White matter