Connectivity Analysis of Cingulotomy Lesion Using Tractography: Do More Effective Targets Exist? Jennifer A. Sweet, MD (1,2); Suraj Thyagaraj, PhD (2); Curtis Tatsuoka, PhD (2); Jonathan P. Miller, MD (1,2); Cameron C. McIntyre, PhD (2) (1) University Hospitals Cleveland Medical Center, Cleveland, OH USA (2) Case Western Reserve University, Cleveland, OH USA

Introduction Methods Conclusion Table 1. Cingulotomy Lesion • Cingulotomy procedures for the • Ten healthy volunteers underwent Tractography based connectivity Connectivity treatment of depression, pain, T1 and diffusion-weighted MRI analysis of cingulotomy lesions and OCD consists of 1-3 bilateral • Regions of interest (ROIs) were compared to subregions of the rostral lesions in the dorsal anterior created to replicate three dorsal CB, showed highest connectivity cingulate cortex and an cingulotomy lesions and eight Fraction of total streamlines from predominantly to dACC. underlying WM tract called the equally-sized subdivisions of the cingulotomy lesions 1-3, that are This suggests that therapeutic effects cingulum bundle (CB) rostral dorsal CB (Figure1) connected to each cortical or subcortical of cingulotomy lesions results from • While cingulotomy is effective, the • Subdivisions (1-3) coincided location; dlFC, dorsolateral frontal cortex; disruption of the connections to the exact region responsible for respectively with the bottom dmFC, dorsomedial frontal cortex; dACC, dACC, and that perhaps lesions made symptom relief is unclear halves of the three lesions dorsal anterior cingulate cortex; sACC, more anteriorly to current cingulotomy • The CB has long been implicated • Deterministic tractography was subgenual anterior cingulate cortex; PCC, targets, might further optimize the in the pathophysiology of performed to assess connectivity posterior cingulate cortex; FP, frontal pole; therapeutic efficacy of the results. psychiatric disorders and certain of each ROI to 11 cortical and m/cOFC, medial/central orbitofrontal CB regions, such as the rostral subcortical brain structures cortex; lOFC, lateral orbitofrontal cortex; References dorsal CB, have greater vlPFC, ventrolateral prefrontal cortex. Heilbronner SR, Haber SN. Frontal cortical connectivity than others, to Results and subcortical projections provide a basis Table 2. Rostral Dorsal Cingulum cortical and subcortical structures • Deterministic tractography was for segmenting the cingulum bundle: Bundle Subregion Connectivity implications for neuroimaging and associated with mood and thought performed seeding from three psychiatric disorders. J. Neurosci. • This study uses tractography to bilateral cingulotomy lesions and 2014;34(30):10041-10054. assess connectivity of standard eight bilateral rostral dorsal CB Yang JC, Ginat DT, Dougherty DD, et al. cingulotomy lesions, compared to subregions Lesion analysis for cingulotomy and limbic subdivisions of the rostral dorsal • All three cingulotomy lesions leucotomy: comparison and correlation with CB, to help shed light on showed greatest connectivity to Fraction of total streamlines from rostral clinical outcomes. J Neurosurg. 120: 152- pathways responsible for the three cortical areas: posterior dorsal CB subregions 1-8 164, 2014. therapeutic effects of cingulotomy Mayberg HS, Liotti M, et al. Reciprocal cingulate cortex (PCC) for lesion Discussion and to determine if other regions limbic-cortical function and negative mood: 1, followed by dorsal anterior Based on their connectivity, the converging PET findings in depression and of the CB might be more effective cingulate cortex (dACC), and then therapeutic effects of cingulotomy normal sadness. Am J Psychiatry. 1999 targets dorsomedial frontal cortex lesions may be due to disruption of May;156(5):675-82 (dmFC); dACC for lesions 2&3, connections to dACC, dmFC, & PCC. Zhang Y, Schuff N, et al. Diffusion tensor followed by dmFC and PCC Figure 1. Regions of Interest for Thus, since subregions 2-5 all show imaging of cingulum fibres in mild cognitive (Table1) Tractography Analysis highest connectivity to dACC, and impairment and Alzheimer’s disease. • The CB subregion with the subregion 1 shares highest Neurology. 2007;68:13–18. greatest connectivity to the PCC connectivity to dACC and PCC, it is was subregion 1, but it showed possible that cingulotomy lesions Acknowledgement equivalent connectivity to dACC positioned more anteriorly to currently This work was supported by the National Region of interest masks replicating three as well. Subregions 2-5 showed placed lesions, may produce more Institutes of Health grant 2KL2TR000440. standard cingulotomy lesions (a), and 8 greatest connectivity to dACC effective results by further disrupting This work made use of the High Performance Computing Resource in the equally-sized subdivisions of the rostral (Table 2) pathways traveling to dACC. Core Facility for Advanced Research dorsal CB (b) Computing at CWRU.