This technology is a closed-loop system combining functional magnetic resonance imaging (fMRI) and electroencephalogram (EEG) to deliver repetitive transcranial magnetic stimulation (rTMS) phase-locked to the individual patient’s alpha wave.
Unmet Need: Synchronizing alpha rhythms with delivery of transcranial magnetic stimulation
Current methods that combine functional magnetic resonance imaging (fMRI), electroencephalogram (EEG), and transcranial magnetic stimulation (TMS) are only capable of simultaneous TMS-EEG recordings and are open-loop. Open-loop systems measure neurophysiological responses after TMS treatment, yet fail to consider the state of the brain during input. In addition, the lack of fMRI recording during treatment omits information related to spatial brain activity. Although fMRI, TMS, and EEG systems exist, there are currently no systems that can perform simultaneous fMRI-EEG recording and utilize these measurements to tune TMS in real-time.
The Technology: fMRI-EEG-TMS system with brain state synchronized rTMS triggering
This technology combines a bipolar electroencephalogram (EEG), magnetic resonance imaging (MRI) scanner, and a transcranial magnetic stimulation (TMS) neurostimulator in a custom built TMS coil positioner and MRI compatible setup. At the start of each treatment session, the individual alpha frequency (IAF) is determined using a short EEG recording. This recording is then used to predict the time point for the next peak for TMS triggering by using a Root Mean Square Error (RMSE) model fit parameter. The predicted time point for the next peak in the alpha rhythm is then scheduled for future triggering. After each rTMS pulse, a new model is fit using EEG measurements to ensure treatment is synchronized with the desired alpha frequency.
This system has been tested in a clinical setting on patients with Major Depressive Disorder (MDD).
Applications:
- Treatment for patients with Major Depressive Disorder (MDD)
- Treatment for patients with motor dysfunction
- Research tool to determine efficacy of transcranial magnetic stimulation (TMS)
- Repetitive TMS treatment in patients with psychological or neurological disorders
- Research tool to determine the effect of TMS on a subject’s motor or visual response
Advantages:
- Phase-locked transcranial magnetic stimulation (TMS) pulse triggering at any angle
- Closed-lop control of TMS triggering
- Simultaneous MRI and EEG recording
- Provides a data processing pipeline to determine and measure an individual’s preferred phase
- Real-time data analysis of EEG recordings
- User-friendly
Lead Inventor:
Paul Sajda, Ph.D.
Related Publications:
Faller J, Doose J, Sun X, Mclntosh JR, Saber GT, Lin Y, Teves JB, Blankenship A, Huffman S, Goldman RI, George MS, Brown TR, Sajda P. “Daily prefrontal closed-loop repetitive transcranial magnetic stimulation (rTMS) produces progressive EEG quasi-alpha phase entrainment in depressed adults” Brain Stimul. 2022 Feb 26; 15(2): 458-471.
Huffman S, Dancy M, Li X, Doose J, Goldman R, Sajda P, Brown T, George M. “Does Synchronizing TMS pulses with EEG alpha Phase improve the Antidepressant Efficacy of Prefrontal TMS?” Brain Stimulation: Basic, Translational, and Clinical Research in Neuromodulation. 2021 Nov 1; 14(6): 1624.
Faller J, Lin Y, Doose J, Saber GT, McIntosh JR, Teves JB, Goldman RI, George MI, Sajda P, Brown T. “An EEG-fMRI-TMS instrument to investigate BOLD response to EEG guided stimulation” IEEE. 2019 Mar; 1054-1057.
- George M, Saber G, McIntosh J, Doose J, Faller J, Lin Y, ... & Brown T. “Combined TMS-EEG-fMRI. The level of TMS-evoked activation in anterior cingulate cortex depends on timing of TMS delivery relative to frontal alpha phase” Brain Stimul. 2019 Mar 1; 12(2): 580.
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