Resting Motor Threshold (RMT) during “Preservation” Transcranial Magnetic Stimulation (TMS)

Abstract

RMT is central to therapeutic TMS. Routine clinical checks may reveal changes and some research has reported changes. It is unclear whether long-term preservation TMS treatment produces accumulative/permanent change in RMT of clinical concern. Our aim was to examine RMT records of participants in preservation TMS for any evidence of possible accumulative/permanent RMT change. The records were accessed of 30 females and 10 males who had received preservation TMS for from 24 to 57 (male) and 60 (female) months. Generalized estimating equations were used to explore trajectories of RMT over time for the overall sample and by age and gender. Some individual records displayed occasional sharp (up or down) spikes, frequently followed by a degree of rectification. The records of the three highest (mean 75.8) and lowest (mean 36.1) RMT scores were free of large variations. There were no significant changes in RMT over time for the total group, or by gender or age. For this group of 40 patients receiving long term TMS, there were no significant changes in the RMT.