P42-F New mobile application for adaptive threshold hunting in transcranial magnetic stimulation

Abstract

Background Use of transcranial magnetic stimulation (TMS) in clinical neurophysiology has expanded as navigated TMS and repetitive TMS therapies have gained popularity. Clinical applications and scientific studies often apply adaptive threshold hunting (ATH) to determine motor threshold (MT). MT expresses corticospinal excitability, and it is used as a baseline stimulation intensity (SI) for modulatory, therapeutic and mapping procedures. Currently available tools for ATH are system-integrated tools and stand-alone software. System-integrated tools are rare, and the available stand-alone software require a dedicated computer adding to laboratory space-requirements. Material and methods I programmed an Android-based “bestPEST” mobile application for ATH to allow for a simple recording of MTs with sharing capabilities and logging. The application applies parameter estimation by sequential testing and was named after Pentlands BestPEST-routine ( Pentland , 1980 ). The application is free through Google Play. For comparison I applied Motor Threshold Assessment Tool 2.0 ( Awiszus and Borckardt, 2012 ) as a reference method. I used data gathered from 15 healthy volunteers to simulate realistic motor evoked potentials (MEPs) utilizing random generator which considered the experimentally measured individual mean MEP amplitude and variation at different SIs ( Kallioniemi et al., 2018 ). Results The MTs of the different methods agreed well (ICC ⩾ 0.989, p Conclusions The bestPEST application produced similar MTs with the reference method, and will help investigators to determine MTs and to log results.