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22 results on '"Veerakumar, Ashan"'

2. Cingulate dynamics track depression recovery with deep brain stimulation

Author

Alagapan, Sankaraleengam, Choi, Ki Sueng, Heisig, Stephen, Riva-Posse, Patricio, Crowell, Andrea, Tiruvadi, Vineet, Obatusin, Mosadoluwa, Veerakumar, Ashan, Waters, Allison C., Gross, Robert E., Quinn, Sinead, Denison, Lydia, O’Shaughnessy, Matthew, Connor, Marissa, Canal, Gregory, Cha, Jungho, Hershenberg, Rachel, Nauvel, Tanya, Isbaine, Faical, Afzal, Muhammad Furqan, Figee, Martijn, Kopell, Brian H., Butera, Robert, Mayberg, Helen S., and Rozell, Christopher J.

Published
2023
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3. Subcallosal cingulate deep brain stimulation evokes two distinct cortical responses via differential white matter activation.

Author

Seas, Andreas, Noor, M. Sohail, Ki Sueng Choi, Veerakumar, Ashan, Obatusin, Mosadoluwa, Dahill-Fuchel, Jacob, Tiruvadi, Vineet, Elisa Xu, Riva-Posse, Patricio, Rozell, Christopher J., Mayberg, Helen S., McIntyre, Cameron C., Waters, Allison C., and Howell, Bryan

Subjects
DEEP brain stimulation, EVOKED potentials (Electrophysiology), WHITE matter (Nerve tissue), ELECTROCONVULSIVE therapy, ELECTROENCEPHALOGRAPHY
Abstract

Subcallosal cingulate (SCC) deep brain stimulation (DBS) is an emerging therapy for refractory depression. Good clinical outcomes are associated with the activation of white matter adjacent to the SCC. This activation produces a signature cortical evoked potential (EP), but it is unclear which of the many pathways in the vicinity of SCC is responsible for driving this response. Individualized biophysical models were built to achieve selective engagement of two target bundles: either the forceps minor (FM) or cingulum bundle (CB). Unilateral 2 Hz stimulation was performed in seven patients with treatment-resistant depression who responded to SCC DBS, and EPs were recorded using 256-sensor scalp electroencephalography. Two distinct EPs were observed: a 120 ms symmetric response spanning both hemispheres and a 60 ms asymmetrical EP. Activation of FM correlated with the symmetrical EPs, while activation of CB was correlated with the asymmetrical EPs. These results support prior model predictions that these two pathways are predominantly activated by clinical SCC DBS and provide first evidence of a link between cortical EPs and selective fiber bundle activation. [ABSTRACT FROM AUTHOR]

Published
2024
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4. 437. A Novel Subcallosal Cingulate Biomarker of Deep Brain Stimulation Mediated Stable Depression Recovery

Author

Alagapan, Sankaraleengam, primary, Heisig, Stephen, additional, Choi, Ki Seung, additional, Waters, Allison, additional, Veerakumar, Ashan, additional, Tiruvadi, Vineet, additional, Obatusin, Mosadoluwa, additional, Nauvel, Tanya, additional, Cha, Jungho, additional, Crowell, Andrea, additional, Figee, Martijn, additional, Posse, Patricio Riva, additional, Butera, Robert, additional, Mayberg, Helen, additional, and Rozell, Christopher, additional

Published
2023
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5. Exploration of acute effects of stimulation frequency on subcallosal cingulate dynamics in SCC DBS

Author

Fitoz, Elif Ceren, primary, Alagapan, Sankaraleengam, additional, Waters, Allison, additional, Tiruvadi, Vineet, additional, Veerakumar, Ashan, additional, Obatusin, Mosadoluwa, additional, Choi, Ki Sueng, additional, Crowell, Andrea, additional, Riva-Posse, Patricio, additional, Butera, Robert, additional, Mayberg, Helen, additional, and Rozell, Christopher, additional

Published
2023
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7. Time-frequency signatures evoked by single-pulse deep brain stimulation to the subcallosal cingulate

Author

Smith, Ezra E., primary, Choi, Ki Sueng, additional, Veerakumar, Ashan, additional, Obatusin, Mosadoluwa, additional, Howell, Bryan, additional, Smith, Andrew H., additional, Tiruvadi, Vineet, additional, Crowell, Andrea L., additional, Riva-Posse, Patricio, additional, Alagapan, Sankaraleengam, additional, Rozell, Christopher J., additional, Mayberg, Helen S., additional, and Waters, Allison C., additional

Published
2022
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14. Longitudinal Changes in Subcallosal Cingulate Local Field Potential Features in Patients Undergoing DBS for Treatment-Resistant Depression

Author

Alagapan, Sankaraleengam, primary, Waters, Allison, additional, Veerakumar, Ashan, additional, Obatusin, Mosadoluwa, additional, Tiruvadi, Vineet, additional, Crowell, Andrea, additional, Riva-Posse, Patricio, additional, Butera, Robert, additional, Mayberg, Helen, additional, and Rozell, Christopher, additional

Published
2020
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16. Field potential 1/f activity in the subcallosal cingulate region as a candidate signal for monitoring deep brain stimulation for treatment-resistant depression

Author

Veerakumar, Ashan, primary, Tiruvadi, Vineet, additional, Howell, Bryan, additional, Waters, Allison C., additional, Crowell, Andrea L., additional, Voytek, Bradley, additional, Riva-Posse, Patricio, additional, Denison, Lydia, additional, Rajendra, Justin K., additional, Edwards, Johnathan A., additional, Bijanki, Kelly R., additional, Choi, Ki Sueng, additional, and Mayberg, Helen S., additional

Published
2019
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19. 674. Subcallosal Cingulate Local Field Potential (SCC-LFP) 1/f Noise Changes during SCC Deep Brain Stimulation (DBS) for Major Depressive Disorder (MDD): Observations across Treatment Phases and Circadian Cycles

Author

Veerakumar, Ashan, primary, Tiruvadi, Vineet, additional, Howell, Bryan, additional, Waters, Allison, additional, Crowell, Andrea, additional, Riva Posse, Patricio, additional, Denison, Lydia, additional, Rajendra, Justin, additional, Seung Choi, Ki, additional, and Mayberg, Helen, additional

Published
2017
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20. Versatile genetic assembly system (VEGAS) to assemble pathways for expression inS. cerevisiae

Author

Mitchell, Leslie A., primary, Chuang, James, additional, Agmon, Neta, additional, Khunsriraksakul, Chachrit, additional, Phillips, Nick A., additional, Cai, Yizhi, additional, Truong, David M., additional, Veerakumar, Ashan, additional, Wang, Yuxuan, additional, Mayorga, María, additional, Blomquist, Paul, additional, Sadda, Praneeth, additional, Trueheart, Joshua, additional, and Boeke, Jef D., additional

Published
2015
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22. Field potential 1/ f activity in the subcallosal cingulate region as a candidate signal for monitoring deep brain stimulation for treatment-resistant depression.

Author

Veerakumar A, Tiruvadi V, Howell B, Waters AC, Crowell AL, Voytek B, Riva-Posse P, Denison L, Rajendra JK, Edwards JA, Bijanki KR, Choi KS, and Mayberg HS

Subjects
Aged, Female, Humans, Longitudinal Studies, Male, Middle Aged, Deep Brain Stimulation methods, Depressive Disorder, Treatment-Resistant therapy, Electrophysiological Phenomena, Gyrus Cinguli, Process Assessment, Health Care
Abstract

Subcallosal cingulate cortex deep brain stimulation (SCC-DBS) is an experimental therapy for treatment-resistant depression (TRD). Refinement and optimization of SCC-DBS will benefit from increased study of SCC electrophysiology in context of ongoing high-frequency SCC-DBS therapy. The study objective was a 7-mo observation of frequency-domain 1/ f slope in off-stimulation local field potentials (SCC-LFPs) alongside standardized measurements of depression severity in 4 patients undergoing SCC-DBS. SCC was implanted bilaterally with a combined neurostimulation-LFP recording system. Following a 1-mo off-stimulation postoperative phase with multiple daily recordings, patients received bilateral SCC-DBS therapy (130 Hz, 90 μs) and weekly resting-state SCC-LFP recordings over a 6-mo treatment phase. 1/ f slopes for each time point were estimated via linear regression of log-transformed Welch periodograms. General linear mixed-effects models were constructed to estimate pretreatment sources of 1/ f slope variance, and 95% bootstrap confidence intervals were constructed to estimate treatment phase 1/ f slope association with treatment response (50% decrease in preimplantation symptom severity). Results show the time of recording was a prominent source of pretreatment 1/ f slope variance bilaterally, with increased 1/ f slope magnitude observed during night hours (2300-0659). Increase in right 1/ f slope was observed in the setting of treatment response, with bootstrap analysis supporting this observation in 3 of 4 subjects. We conclude that 1/ f slope can be measured longitudinally in a combined SCC-DBS/LFP recording system and likely conforms to known 1/ f circadian variability. The preliminary evidence of 1/ f slope increase during treatment response suggests a potential utility as a candidate biomarker for ongoing development of adaptive TRD-neuromodulation strategies. NEW & NOTEWORTHY In four patients with treatment-resistant depression undergoing therapeutic deep brain stimulation (DBS), we present the first longitudinal observations of local field potentials (LFP) from the subcallosal cingulate region outside the postoperative period. Specifically, our results demonstrate that frequency-domain 1/ f activity is measurable in a combined DBS-LFP recording system and that right hemisphere recordings appear sensitive to mood state, thus suggesting a potential readout suitable for consideration in ongoing efforts to develop adaptive DBS delivery systems.

Published
2019
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