EEG-triggered TMS as a promising approach to the treatment of schizophrenia
Presenting author:
EEG-triggered TMS as a possible approach for schizophrenia treatment
Baklushev M.E., Nazarova M.A., Nikulin V.V., Novikov P.A.
Centre for Cognition & Decision Making, National Research University Higher School of Economics, Moscow, Russia
Transcranial magnetic stimulation (TMS) is currently used in schizophrenia to treat auditory hallucinations and negative symptoms. The level of evidence of TMS in schizophrenia is rather low - "C", according to the clinical recommendations of 2020. The current trend in TMS-research is the development of protocols allowing to synchronize TMS with subject's neuronal activity: frequency. Such protocols are called state-dependent or EEG-triggered TMS. In experiments involving healthy subjects, it was shown that EEG-dependent TMS of both the motor and sensory cortices may result in a number of electrophysiological and behavioral effects, which are different or superior to the effects of conventional TMS protocols.
We reviewed the existing TMS protocols used in schizophrenia, including stimulation of the temporo-parietal cortex, dorsolateral prefrontal cortex, and cerebellum at frequencies from 1 to 20 Hz, including stimulation at individual alpha frequency and theta-burst stimulation. We propose new EEG-dependent TMS protocols based on pathogenetic targets characteristic for schizophrenia such as decreased alpha rhythm power, excessive gamma resting activity, and impaired functional connectivity among prefrontal cortex and many others brain regions. We propose to use several approaches to increase the current TMS protocols in schizophrenia (1) TMS synchronization with the phase of the ongoing alpha and beta oscillations; (2) a phase-synchronized TMS of two brain regions, in particular the cerebellum at 5 Hz and the dorsolateral prefrontal cortex at 10 Hz to restore functional connectivity between these regions. In this case, a gradual phase synchronization between these regions and a cross-frequency iteration occurs, which can be considered as a kind of "training" of functional connectivity. It is suggested that by applying these approaches, it might be possible to influence negative and cognitive symptoms of schizophrenia in a more effective way.
Baklushev M.E., Nazarova M.A., Nikulin V.V., Novikov P.A.
Centre for Cognition & Decision Making, National Research University Higher School of Economics, Moscow, Russia
Transcranial magnetic stimulation (TMS) is currently used in schizophrenia to treat auditory hallucinations and negative symptoms. The level of evidence of TMS in schizophrenia is rather low - "C", according to the clinical recommendations of 2020. The current trend in TMS-research is the development of protocols allowing to synchronize TMS with subject's neuronal activity: frequency. Such protocols are called state-dependent or EEG-triggered TMS. In experiments involving healthy subjects, it was shown that EEG-dependent TMS of both the motor and sensory cortices may result in a number of electrophysiological and behavioral effects, which are different or superior to the effects of conventional TMS protocols.
We reviewed the existing TMS protocols used in schizophrenia, including stimulation of the temporo-parietal cortex, dorsolateral prefrontal cortex, and cerebellum at frequencies from 1 to 20 Hz, including stimulation at individual alpha frequency and theta-burst stimulation. We propose new EEG-dependent TMS protocols based on pathogenetic targets characteristic for schizophrenia such as decreased alpha rhythm power, excessive gamma resting activity, and impaired functional connectivity among prefrontal cortex and many others brain regions. We propose to use several approaches to increase the current TMS protocols in schizophrenia (1) TMS synchronization with the phase of the ongoing alpha and beta oscillations; (2) a phase-synchronized TMS of two brain regions, in particular the cerebellum at 5 Hz and the dorsolateral prefrontal cortex at 10 Hz to restore functional connectivity between these regions. In this case, a gradual phase synchronization between these regions and a cross-frequency iteration occurs, which can be considered as a kind of "training" of functional connectivity. It is suggested that by applying these approaches, it might be possible to influence negative and cognitive symptoms of schizophrenia in a more effective way.