Neuroimaging in lesioning therapy for obsessive-compulsive disorder: region-based and network analysis of
Lyndon Boone1, Mahan Shafie2, Aariz Naeem3
1Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada; Sunnybrook Research Institute, Toronto, ON, Canada.
Introduction:
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.
Methods:
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.
Results:
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.
Conclusion:
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.
