Saba Amiri1, Mohammad Arbabi2, Kamran Kazemi3, Mansour Parvaresh-Rizi4, Mehdi M Mirbagheri5. 1. Medical Physics and Biomedical Engineering Department, Faculty of Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran. 2. Psychiatry, Psychosomatic Medicine Research Center Department, Tehran University of Medical Sciences, Tehran, Iran. 3. Electrical and Electronics Engineering Department, Shiraz University of Technology, Shiraz, Iran. Electronic address: kazemi@sutech.ac.ir. 4. Neurosurgery Department, Iran University of Medical Sciences (IUMS), Tehran, Iran. 5. Medical Physics and Biomedical Engineering Department, Faculty of Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran; Physical Medicine and Rehabilitation Department, Northwestern University, USA. Electronic address: Mehdi@northwestern.edu.
Abstract
OBJECTIVE: To characterize the functional connectivity (FC) of target brain regions for deep brain stimulation (DBS) in patients with treatment-resistant depression (TRD), and to evaluate its gender and brain lateralization dependence. METHODS: Thirty-one TRD patients and twenty-nine healthy control (HC) subjects participated. FC of subcallosal cingulate gyrus (SCG), ventral caudate (VCa), nucleus accumbens (NAc), lateral habenula (LHb), and inferior thalamic peduncle (ITP) were evaluated using resting-state fMRI. FC was characterized by calculating the nodal 'degree', a major feature of the graph theory. RESULTS: The degree measures of the left and right VCa, the left LHb, and the left ITP were significantly greater in the TRD than in the HC group. The degree was greater in females with TRD in all these regions except the right LHb. Finally, the left hemisphere was generally more affected by depression and presented significant degrees in LHb and ITP regions of the patients. CONCLUSION: Our findings demonstrate the ability of degree to characterize brain FC and identify the regions with abnormal activities in TRD patients. This implies that the degree may have the potential to be used as an important graph-theoretical feature to further investigate the mechanisms underlying TRD, and consequently along with other diagnostic markers, to assist in the determination of the appropriate target region for DBS treatment in TRD patients.
OBJECTIVE: To characterize the functional connectivity (FC) of target brain regions for deep brain stimulation (DBS) in patients with treatment-resistant depression (TRD), and to evaluate its gender and brain lateralization dependence. METHODS: Thirty-one TRD patients and twenty-nine healthy control (HC) subjects participated. FC of subcallosal cingulate gyrus (SCG), ventral caudate (VCa), nucleus accumbens (NAc), lateral habenula (LHb), and inferior thalamic peduncle (ITP) were evaluated using resting-state fMRI. FC was characterized by calculating the nodal 'degree', a major feature of the graph theory. RESULTS: The degree measures of the left and right VCa, the left LHb, and the left ITP were significantly greater in the TRD than in the HC group. The degree was greater in females with TRD in all these regions except the right LHb. Finally, the left hemisphere was generally more affected by depression and presented significant degrees in LHb and ITP regions of the patients. CONCLUSION: Our findings demonstrate the ability of degree to characterize brain FC and identify the regions with abnormal activities in TRD patients. This implies that the degree may have the potential to be used as an important graph-theoretical feature to further investigate the mechanisms underlying TRD, and consequently along with other diagnostic markers, to assist in the determination of the appropriate target region for DBS treatment in TRD patients.