Reduced auditory perception and brain response with quiet TMS coil

Autor: David L.K. Murphy, Lari M. Koponen, Eleanor Wood, Yiru Li, Noreen Bukhari-Parlakturk, Stefan M. Goetz, Angel V. Peterchev
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Brain Stimulation, Vol 17, Iss 6, Pp 1197-1207 (2024)
Druh dokumentu: article
ISSN: 1935-861X
DOI: 10.1016/j.brs.2024.10.003
Popis: Background: Electromagnetic forces in transcranial magnetic stimulation (TMS) coils generate a loud clicking sound that produces confounding auditory activation and is potentially hazardous to hearing. To reduce this noise while maintaining stimulation efficiency similar to conventional TMS coils, we previously developed a quiet TMS double containment coil (qTMS-DCC). Objective: To compare the stimulation strength, perceived loudness, and EEG response between qTMS-DCC and a commercial TMS coil. Methods: Nine healthy volunteers participated in a within-subject study design. The resting motor thresholds (RMTs) for qTMS-DCC and MagVenture Cool-B65 were measured. Psychoacoustic titration matched the Cool-B65 loudness to qTMS-DCC pulsed at 80, 100, and 120 % RMT. Event-related potentials (ERPs) were recorded for both coils. The psychoacoustic titration and ERPs were acquired with the coils both on and 6 cm off the scalp, the latter isolating the effects of airborne auditory stimulation from body sound and electromagnetic stimulation. The ERP comparisons focused on a centro-frontal region that encompassed peak responses in the global signal while stimulating the primary motor cortex. Results: RMT did not differ significantly between the coils, with or without the EEG cap on the head. qTMS-DCC was perceived to be substantially quieter than Cool-B65. For example, qTMS-DCC at 100 % coil-specific RMT sounded like Cool-B65 at 34 % RMT. The general ERP waveform and topography were similar between the two coils, as were early-latency components, indicating comparable electromagnetic brain stimulation in the on-scalp condition. qTMS- DCC had a significantly smaller P180 component in both on-scalp and off-scalp conditions, supporting reduced auditory activation. Conclusions: The stimulation efficiency of qTMS-DCC matched Cool-B65 while having substantially lower perceived loudness and auditory-evoked potentials.
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