Deep brain stimulation (DBS) has emerged as a promising therapy for patients with treatment-resistant obsessive-compulsive disorder (OCD), an illness that arises as a result of dysfunction across broad neural networks distributed across the brain. However, it remains challenging to customize DBS therapy for each patient due to variation in the functional dysfunction observed in these networks. Recently, researchers at Texas Children’s Hospital and Baylor College of Medicine, along with their colleagues at Brigham and Women’s Hospital, conducted the first blind testing of a novel ‘connectomic’ model designed to customize DBS surgery for OCD patients. The model was based on a 2020 study conducted at Brigham and Women’s Hospital, which identified an ‘OCD response tract’ – a brain region that could be modulated by DBS to improve clinical outcomes in OCD patients.
To develop a predictive connectomic model, the researchers used connectomic imaging strategies to map the location and direction of white matter bundles and their constituent fibers within the brain. A three-dimensional magnetic resonance imaging technique called white matter tractography was used to identify these networks and inform surgeons of where to implant the DBS electrodes in the patient’s brain. The researchers used this approach to rank and conduct a blind comparison of clinical outcomes in ten OCD patients who had undergone a specific DBS procedure six months prior to the study.
During the study, DBS programming was performed by Dr. Wayne Goodman, Chair of the department of psychiatry at Baylor College, and patient outcomes were periodically assessed by Dr. Eric Storch, Vice Chair of psychology, to track changes in the severity of their OCD and mood symptoms. Meanwhile, the Brigham and Women’s Hospital (BWH) team led by Dr. Andreas Horn analyzed the imaging data and provided rank predictions based solely on the neuroimaging data and stimulation parameters. This team was not involved in DBS planning or programming and did not have prior knowledge of clinical outcomes. The outcomes predicted by the BWH team closely matched the actual clinical outcomes observed by the Baylor team in these patients.
This research is the first example of such a collaborative, blinded effort by two research centers to validate DBS therapy for a brain tract proposed based on retrospective data. The study involved the “connectomic” mapping on the specific fiber bundles and brain regions whose modulation by DBS could improve clinical outcomes in OCD patients. Ultimately, this collaborative approach could serve as a model for validating and optimizing DBS therapies for other neurological conditions in future research.
Overall, this study provides valuable insights into the effectiveness of DBS therapy for patients with treatment-resistant OCD. By developing a predictive connectomic model, researchers have demonstrated that mapping the neural connections involved in specific conditions and understanding how these connections are affected by DBS can improve clinical outcomes. This research could pave the way for more tailored DBS therapies that can offer improved relief to patients with a range of neurological and neuropsychiatric disorders.