Title: 2578 - Effect of Repetitive Transcranial Magnetic Stimulation on Perceptual Distortion


Simple Futarmal Kothari (Presenter)
Aarhus University

Lilja Dagsdottir, Aarhus University
Mohit Kothari, Regionshospital Hammel Neurocenter
Jakob Blicher, Aarhus University
Abhishek kumar, Karolinska Institutet
Poul Erik Buchholtz, Aarhus University
Mahmoud Ashkania, Aarhus University
Peter Svensson, Aarhus University


Objectives: Chronic orofacial pain patients often perceive the painful face area as “swollen” without clinical signs – a phenomenon known as perceptual distortion (PD). This study tested the neuromodulatory effect of repetitive transcranial magnetic stimulation (rTMS) on PD in order to gain an insight into the possible underlying cortical mechanisms important for coding PD.

Methods: This study was a single-blinded, randomized, and placebo controlled trial, consisting of 52 healthy individuals: Group I (n=26) receiving active rTMS; Group II (n=26) receiving sham rTMS. PD was induced by administering infraorbital local anesthesia (LA). It was measured as perceived change in the size of the affected face area using a numerical rating scale. In addition, mechanical and visual stimuli were applied. The participants rated the PD at baseline, 6 mins after LA administration, immediately, 20 and 40 mins after rTMS. PD was rated both before and after the stimuli. The rTMS (active and sham) was applied to face (lip) representation area of primary somatosensory cortex (SI) as an intervention at 10 min after the LA administration, which is when the magnitude of PD is large. Continuous theta-burst stimulation paradigm (50 Hz) for 40 s was employed as an active rTMS. Analysis of variance was used to compare the magnitude of PD at different time points between the groups.

Results: There was a significant decrease in the magnitude of PD immediately and 20 min after the application of active rTMS compared with sham rTMS (P<0.006). Further, upon visual stimulation, the magnitude of PD significantly decreased immediately, 20 and 40 min after the application of active rTMS compared with sham rTMS (P<0.001).

Conclusions: Active rTMS applied to a somatotopical-relevant cortical region appears to modulate PD of the face. Future studies will be needed to examine the effects of rTMS on PD and chronic orofacial pain.

Student Presenter

This abstract is based on research that was funded entirely or partially by an outside source:
Danish Research Council (Det Frie Forskningsråd (DFF)

Disclosure Statement:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: NONE