Predicting response to psychiatric surgery: a systematic review of neuroimaging findings

Background: Psychiatric surgery, including deep brain stimulation and stereotactic ablation, is an important treatment option in severe refractory psychiatric illness. Several large trials have demonstrated response rates of approximately 50%, underscoring the need to identify and select responders preoperatively. Recent advances in neuroimaging have brought this possibility into focus. We systematically reviewed the psychiatric surgery neuroimaging literature to assess the current state of evidence for preoperative imaging predictors of response. Methods: We performed this study in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) frameworks, and preregistered it using PROSPERO. We systematically searched the Medline, Embase and Cochrane databases for studies reporting preoperative neuroimaging analyses correlated with clinical outcomes in patients who underwent psychiatric surgery. We recorded and synthesized the methodological details, imaging results and clinical correlations from these studies. Results: After removing duplicates, the search yielded 8388 unique articles, of which 7 met the inclusion criteria. The included articles were published between 2001 and 2018 and reported on the outcomes of 101 unique patients. Of the 6 studies that reported significant findings, all identified clusters of hypermetabolism, hyperconnectivity or increased size in the frontostriatal limbic circuitry. Limitations: The included studies were few and highly varied, spanning 2 decades. Conclusion: Although few studies have analyzed preoperative imaging for predictors of response to psychiatric surgery, we found consistency among the reported results: most studies implicated overactivity in the frontostriatal limbic network as being correlated with clinical response. Larger prospective studies are needed. Registration: www.crd.york.ac.uk/prospero/display_record.php?RecordID=131151.

Magnetic Resonance-Guided Focused Ultrasound Capsulotomy for Treatment-Resistant Psychiatric Disorders

BACKGROUND Psychiatric surgery is an important domain of functional neurosurgery and involves deep brain stimulation (DBS) or lesional procedures performed for treatment-resistant psychiatric illness. It has recently become possible to use magnetic-guided focused ultrasound (MRgFUS) to perform bilateral capsulotomy, a lesional technique commonly carried out with surgical radiofrequency ablation or stereotactic radiosurgery. MRgFUS offers several advantages, including improved safety and real-time imaging of the lesions. OBJECTIVE To describe the clinical and technical aspects of performing bilateral MRgFUS capsulotomy in patients with severe refractory depression and obsessive-compulsive disorder. METHODS We describe the clinical and technical considerations of performing MRgFUS capsulotomy. Topics discussed include patient selection, headframe application, targeting, sonication strategies, and follow-up procedures. RESULTS MRgFUS capsulotomy was performed in 16 patients without serious clinical or radiographic adverse events. CONCLUSION MRgFUS allows for a safe, less invasive technique for performing a well-studied psychiatric surgery procedure—the anterior capsulotomy.