# Neuroimaging in lesioning therapy for obsessive-compulsive disorder: region-based and network analysis of preoperative outcome predictors and postoperative effects

## TL;DR

This paper reviews neuroimaging studies to identify brain regions and networks that predict outcomes and explain mechanisms in OCD lesioning therapy.

## Contribution

The study systematically maps preoperative predictors and postoperative brain changes in OCD lesioning therapy using region-based and network analyses.

## Key findings

- The dorsal anterior cingulate cortex is frequently linked to preoperative response prediction in OCD lesioning.
- Postoperative imaging shows decreased activity in fronto-striatal regions and less consistent changes in cortical and cerebellar areas.
- Network analyses highlight the insula, paracingulate, and middle temporal gyrus as central nodes in postoperative brain changes.

## Abstract

•Preoperative imaging predictors of OCD lesioning response are in their infancy.•The dACC is frequently implicated in predictive findings, warranting further study.•Postoperative imaging consistently suggests decreased fronto-striatal activity.•Widespread cortical & cerebellar changes beyond CSTC circuits remain underexplored.•Normative connectivity reveals central network hubs after lesioning.

Preoperative imaging predictors of OCD lesioning response are in their infancy.

The dACC is frequently implicated in predictive findings, warranting further study.

Postoperative imaging consistently suggests decreased fronto-striatal activity.

Widespread cortical & cerebellar changes beyond CSTC circuits remain underexplored.

Normative connectivity reveals central network hubs after lesioning.

Lesioning procedures such as capsulotomy and cingulotomy offer therapeutic options for patients with severe, treatment-resistant obsessive–compulsive disorder (OCD). However, treatment response remains variable, and mechanisms underlying clinical improvement are poorly understood. Neuroimaging may help identify response predictors and elucidate mechanisms of action.

We systematically reviewed neuroimaging findings from studies of lesioning therapy for OCD, focusing on preoperative predictors of response and postoperative imaging changes. To synthesize findings, we performed region-based frequency mapping alongside connectivity analyses to characterize the functional networks embedding these regions.

Twenty-four studies met inclusion criteria. Six reported preoperative neuroimaging findings associated with clinical response. Across heterogeneous modalities and metrics, the dorsal anterior cingulate cortex was most frequently implicated in predictive findings. Twenty studies reported postoperative changes, with frequent reductions in volume, metabolism, and connectivity noted in the prefrontal cortex, striatum, and thalamus. Less consistent changes were reported in widespread cortical regions and the cerebellum. Symptom reduction did not significantly differ across affected areas. Connectivity analyses revealed that the insula, paracingulate, and middle temporal gyrus may serve as central nodes within the network linking regions of postoperative change.

Despite high methodological heterogeneity and small sample sizes in the primary literature, these findings underscore the potential of neuroimaging to inform patient selection and clarify mechanisms of OCD lesioning therapy. Network analyses may provide a framework for considering novel therapeutic targets. Future prospective research should verify the role of the anterior cingulate cortex in predicting treatment response, and further explore mechanistic changes in distributed brain circuits.