Lesion network mapping analysis identifies potential cause of post-operative depression in a case of cingulate low-grade glioma.

Abstract

BACKGROUND\nDepression following resection of diffuse low-grade gliomas (DLGG) has rarely been described. The location of the tumor or surgical route are among a multitude of potential causes. Lesion-network mapping (LNM), leveraging high quality resting-state fMRI data from large samples of healthy adults, has been used to explore the broader network connectivity for given lesions. However, LNM has not been applied to large intra-axial masses or surgical lesions. Here we utilized LNM to examine a potential cause of postoperative depression in a patient with a cingulate DLGG (Zones I-III).\n\n\nCASE DESCRIPTION\nThis 34-year female underwent surgery for medically refractory seizures attributable to the lesion. A near-total resection was attained through a single-stage, trans-cortical route through the medial prefrontal cortex. Despite seizure-freedom and lack of tumor growth (42 months follow-up), she developed symptoms of major depressive disorder (MDD) soon after surgery that have persisted. To identify functional networks potentially engaged by the surgical corridor and tumor resection cavity, both were segmented separately and used as seeds for normative resting-state fMRI connectivity mapping. Then, to study depression specifically, networks associated with the tumor and surgical approach were compared to those associated with subgenual cingulate deep brain stimulation (DBS). The LNM results suggested that the surgical corridor, rather than the tumor, had greater overlap with DBS-based depression networks (32% vs 8%).\n\n\nCONCLUSION\nThe early postoperative development of MDD following resection of a cingulate region tumor, though likely multi-factorial, should be considered and patients appropriately counselled preoperatively. Further validation of LNM as a viable methodology for correlating symptoms to lesion(s) could make it a valuable tool in selection of surgical approach and patient counseling.