Wednesday, Jun 25: 5:45 PM - 7:00 PM
Oral Sessions
Brisbane Convention & Exhibition Centre
Room: Great Hall
Presentations
Growing knowledge of the link between brain connectivity and transcranial magnetic stimulation (TMS) treatment response has driven recent advances in target refinement and, in turn, treatment efficacy in major depressive disorder (MDD). Notably, mounting evidence suggests that prospectively targeting TMS to dorsolateral prefrontal cortex (DLPFC) sites according to connectivity with the subgenual anterior cingulate cortex (sgACC) might improve therapeutic outcomes in adult MDD.1–6 However, outcome variability remains, with sex differences widely implicated as a contributor7, yet the potential mechanism underlying this difference has remained unexplored.
Here, we explored whether sex differences may exist in DLPFC-sgACC functional connectivity. We also assessed the potential contribution of sex to variability in clinical outcomes in 51 adult patients who received personalized connectivity-guided TMS for treatment of refractory MDD.
Presenter
Nga Yan Tse, Systems Lab, Department of Psychiatry, The University of Melbourne Carlton, VIC
Australia
The spinal cord, a vital component of the central nervous system, plays a critical role in regulating sensorimotor functions through complex neural networks. Despite its importance, the detailed characterization of its motor mechanisms is not yet fully understood and remains an area of active investigation. To address this gap, we utilize a multimodal approach integrating transcranial magnetic stimulation (TMS) for standardized and involuntary motor cortex activation with fMRI to map corresponding spinal cord activity. This method offers a robust framework for systematically elucidating the sensorimotor aspects of spinal circuitry.
Suicidal ideation is a severe symptom of depression and a critical precursor to suicide, requiring effective interventions(Grant, 2018; May, 2015). Transcranial alternating current stimulation (tACS), a novel non-invasive neuromodulation technique, has shown promise in treating neuropsychiatric disorders(Miranda, 2013; Berényi, 2018; Wang, 2022). However, its efficacy in alleviating suicidal ideation in depression and the underlying mechanisms remain unclear. This study aims to evaluate the therapeutic effects of tACS on suicidal ideation and investigate its potential mechanisms.
Presenter
Yuanyuan Guo, Department of Neurology, The First Affiliated Hospital of Anhui Medical University
Department of Neurology, The First Affiliated Hospital of Anhui Medical University
Hefei, Anhui
China
The zona incerta (ZI)–a brain structure implicated in various functions (Mitrofanis, 2005)–is a target for deep brain stimulation (DBS) in essential tremor (ET) (Plaha et al., 2011) and Parkinson's disease (Blomstedt et al., 2018). Yet, precise stereotactic ZI targeting remains challenging due to poor direct visualization. We propose a novel approach by combining (i) our previous in vivo labeling of the human ZI based on 7 Tesla MRI T1 mapping (Lau et al., 2020) and (ii) cortico-incertal structural connectivity maps derived from high-quality diffusion MRI (dMRI) datasets of the Human Connectome Project (HCP) (Van Essen et al., 2012).
Presenter
Roy Haast, Aix-Marseille University
Faculté de Médecine
Marseille Cedex 05, Provence-Alpes-Côte
France
Reward, not only elicits positive emotions (liking), but also generates consummatory behaviour (wanting) (Berridge et al., 2009). Neural studies have indicated the nucleus accumbens (NAc) plays an important role in reward-induced pleasure and motivation (Berridge & Robinson, 2016). However, due to the reliance on neuroimaging methods in existing research and the lack of studies directly stimulated the NAc in healthy individuals, the causal relationship between reward and the NAc remains unclear. Temporal interference stimulation (TIS), a novel non-invasive technique (Grossman et al., 2017), enables selective stimulation of deep brain regions like the NAc without affecting the overlying cortex. This study employs TIS to investigate the direct causal relationship between the NAc and reward, and further explore the dissociation between liking and wanting.
Presenter
Shilin Wen, University of Science and Technology of China Hefei, Anhui
China
The anterior and centromedian thalamic nuclei (ATN, CM) are commonly targeted regions in deep brain stimulation (DBS) for epilepsy (Fig 1A). The motivation for this target strategy is related to the circuits they are involved in. On the one hand, the ATN, which plays a vital role in seizure propagation of focal epilepsy with a mesial temporal focus, is a core node of the Papez circuit that is central to the functional dynamics of the entire limbic structures. On the other hand, the CM, often associated with generalized epilepsy, is also the core of the cerebello-thalamic-cortical (CTC) circuit characterized by diffuse cortical projections [1]. While the efficacy of targeting these nuclei has been previously replicated, the details of the biological substrates that may affect its outcomes remain poorly understood. Here, we sought to address this question by assessing i) the relation between DBS target accuracy and seizure reduction, ii) pathological effects on the thalamic nuclei and their white matter bundles based on the morphological analysis and track density imaging (TDI) and finally iii) the clinical utility of these neuroimaging features to classify responder and non-responder groups (RG/NRG).
Presenter
Yejin Ann, Sungkyunkwan University Gyeonggi-do, Suwon-si
Korea, Republic of