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ORIGINAL RESEARCH
Determining targets for personalized multitarget noninvasive stimulation of the frontoparietal control network
Correspondence should be addressed: Alexandra G. Poydasheva
Volokolamskoye shosse, 80, Moscow, 125310, Russia; ur.ygoloruen@avehsadyop
Funding: the study was conducted as part of the project “Developing a Transcranial Magnetic Stimulation Method to Improve Cognitive Functions in Healthy Individuals” implemented within the framework of the National Project “New Health Preservation Technologies” (registration number 1025020400006-8-3.2.25).
Author contribution: Poydasheva AG, Sinitsyn DO, Bakulin IS — study planning and design; Poydasheva AG, Zabirova AH — literature review; Bakulin IS, Zabirova AH, Lagoda DYu — data acquisition; Sinitsyn DO, Poydasheva AG — data analysis; Poydasheva AG, Sinitsyn DO — manuscript writing; all authors — data interpretation, manuscript editing.
Compliance with ethical standards: the study was approved by the Ethics Committee of the Russian Сenter of Neurology and Neurosciences (protocol No. 5-1/25 dated 19 May 2025). All the volunteers signed the informed consent form.
Personalization of selecting a target for rTMS is a problem, solving which can significantly increase the method efficacy. Stimulation of the key hubs of individual-level resting-state networks represents an approach to personalization. The study aimed to develop an rTMS personalization method based on the selection of individual frontoparietal control network (FPCN) hubs and assessment of their localization variability. To determine the FPCN hubs, individual maps were built using the FPCN group mask as a seed. The searchlight algorithm with the sphere radius of 5 mm was used to select targets within the dorsolateral prefrontal cortex (DLPFC) and posterior parietal cortex (PPC). The target spatial localization variability and correctness of using the routine “5 cm rule” for the DLPFC localization were analyzed. In 24 healthy volunteers (9 males, average age 29±7 years), high interindividual variability of targets was demonstrated. In no area is there a universal position of the stimulation coil that would effectively stimulate targets in all volunteers. Spatial dispersion of points is higher in the DLPFC (volumes of the polyhedral containing the point sets are 2095 mm3 in the DLPFC and 739 mm3 in the PPC). All individual targets in the DLPFC are located within the FPCN mask, while in the PPC some targets are outside this mask. The average distance between the М1 zones and DLPFC is 64±13 mm. In 75% of the subjects, this exceeds 5 cm, which confirms that it was incorrect to use the routine “5 cm rule” for coil positioning in the majority of subjects. An algorithm to select personalized targets for rTMS based on the resting-state fMRI data in the DLPFC and PPC being the key FPCN hubs has been developed.
Keywords: multitarget transcranial magnetic stimulation, personalization, resting-state networks, frontoparietal control network