The Past, Current and Future Research in Cerebellar TMS Evoked Responses—A Narrative Review

TL;DR

This review explores the use of cerebellar TMS-EEG, highlighting its potential and challenges in studying brain function and disease.

Contribution

The paper provides a comprehensive overview of technical challenges and future directions in cerebellar TMS-EEG research.

Findings

Cerebellar TMS-EEG shows promise but faces issues like muscle twitches and sensory contamination.

Variability in experimental methods leads to inconsistent results across studies.

Addressing technical limitations is crucial for advancing cerebellar TMS-EEG research.

Abstract

Transcranial magnetic stimulation coupled with electroencephalography (TMS-EEG) is a novel technique to investigate cortical physiology in health and disease. The cerebellum has recently gained attention as a possible new hotspot in the field of TMS-EEG, with several reports published recently. However, EEG responses obtained by cerebellar stimulation vary considerably across the literature, possibly due to different experimental methods. Compared to conventional TMS-EEG, which involves stimulation of the cortex, cerebellar TMS-EEG presents some technical difficulties, including strong muscle twitches in the neck area and a loud TMS click when double-cone coils are used, resulting in contamination of responses by electromyographic activity and sensory potentials. Understanding technical difficulties and limitations is essential for the development of cerebellar TMS-EEG research. In this review, we summarize findings of cerebellar TMS-EEG studies, highlighting limitations in experimental design and potential issues that can result in discrepancies between experimental outcomes. Lastly, we propose a possible direction for academic and clinical research with cerebellar TMS-EEG.

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