Fractional anisotropy changes after several weeks of daily left high-frequency repetitive transcranial magnetic stimulation of the prefrontal cortex to treat major depression

F. Andrew Kozel, Kevin A. Johnson, Ziad Nahas, Paul A. Nakonezny, Paul S. Morgan, Berry S. Anderson, Samet Kose, Xingbao Li, Kelvin O. Lim, Madhukar H. Trivedi, Mark S. George

Research output: Contribution to journalArticle

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Objectives: As part of a sham controlled treatment trial using daily left repetitive transcranial magnetic stimulation (rTMS), brain changes associated with 4 to 6 weeks of treatment were examined using diffusion tensor imaging to noninvasively evaluate prefrontal white matter (WM) microstructure. A decrease in fractional anisotropy values of the left prefrontal WM could indicate damage to the region. Methods: Diffusion tensor imaging was performed before and after 4 to 6 weeks of daily rTMS treatments. Mean fractional anisotropy levels associated with active rTMS and sham rTMS for the right and left prefrontal WM were assessed. Results: Adequate images were acquired for 8 participants (active n = 4, sham n = 4) before and after rTMS. A mean increase was found for the left prefrontal WM. The mixed model revealed a trend toward a significant treatment group × region interaction effect (P = 0.11). Furthermore, simple region effects (left prefrontal WM vs right prefrontal WM) were at a trend toward significance for difference after treatment within the active rTMS group (P = 0.07), but not within the sham rTMS group (P = 0.88). Conclusions: Repetitive transcranial magnetic stimulation resulted in no evidence of damage to WM on the side of stimulation. Diffusion tensor imaging may offer a unique modality to increase our understanding of mechanisms of action for rTMS.

Original languageEnglish (US)
Pages (from-to)5-10
Number of pages6
JournalJournal of ECT
Issue number1
StatePublished - Mar 1 2011



  • depression
  • diffusion tensor imaging
  • mixed linear model analysis of repeated measures
  • transcranial magnetic stimulation

ASJC Scopus subject areas

  • Neuroscience (miscellaneous)
  • Psychiatry and Mental health

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