Transcranial Magnetic Stimulation: A non-invasive neuromodulation technique for altering neuronal networks in the brain*

Transcranial Magnetic Stimulation (TMS) can tune brain functions non-invasively, safely, and effectively without the need for surgery or drugs. Thus, it can enable the treatment of several debilitating neurological obsessive-compulsive disorders, and migraine [1]. My lab has designed and fabricated an anatomically accurate human brain phantom that can be used to test the feasibility and safety of several TMS protocols. We have investigated a feasibility study of combined TMS and DBS using brain phantom in collaboration with the VCU Dept. of Neurosurgery [2], [3]. We have also designed and fabricated novel focal stimulation coils based on novel soft ferromagnetic materials that can stimulate only a local region of the primary motor cortex. We are currently working to experimentally verify the results from coil design in rats in collaboration with the Dept. of Neurology at VCU [4]. We are also working to establish an accurate mechanism underlying TMS by investigating the neuronal firing patterns in several brain regions induced by cortical stimulation and by establishing the role of individual nuclei in affecting other nuclei of the motor circuitry. My team has also designed a TMS coil configuration that can stimulate multiple sites simultaneously and vary sites of stimulation without moving the coils physically. These new TMS techniques will enable the future development of effective TMS protocols for the diagnosis and treatment of several neurological and psychiatric disorders.

References: 

[1]  S. Rossi et al., “Safety and recommendations for TMS use in healthy subjects and patient populations, with updates on training, ethical and regulatory issues: Expert Guidelines,” Clin. Neurophysiol., 132, p. 269, 2021.

[2]  H. Magsood, et al., Front. Hum. Neurosci., 14, p. 123, 2023.

[3] H. Magsood and R. L. Hadimani, Mater. Sci. Eng. C, 120, p. 111705, 2021.

[4] I. C. Carmona, D. Kumbhare, M. S. Baron, and R. L. Hadimani,  AIP Adv., 11,  p. 025210, 2021.