Neural Correlates of the Antinociceptive Effects of Repetitive Transcranial Magnetic Stimulation on Central Pain After Stroke
Neurorehabilitation and Neural Repair, 05/25/2012
Ohn SH et al. – Mood may affect the modest antinociceptive effects of Repetitive transcranial magnetic stimulation (rTMS) that the authors found, which may be mediated by the superior thalamocortical tract (TCT) through modulation of a distributed pain network.Methods
- Each patient underwent daily 10-Hz rTMS sessions for 1000 pulses on 5 consecutive days over the hotspot for the first dorsal interosseus muscle.
- Pain severity was monitored using the Visual Analogue Scale (VAS).
- Mood was assessed by the Hamilton Depression Rating Scale.
- Clinical data from all participants along with the DTI and fMRI findings from 10 patients were analyzed.
- VAS scores decreased significantly, if modestly, following administration of rTMS in 14 responders, which lasted for 2 weeks after the intervention.
- Regression analysis showed a significant correlation between less initial depression and higher antalgic effect of rTMS.
- Integrity of the superior TCT in the ipsilesional hemisphere showed significant correlation with change of VAS score after rTMS.
- fMRI showed significantly decreased activity in the secondary somatosensory cortex, insula, prefrontal cortex, and putamen in rTMS responders, whereas no change was noted in nonresponders.