Transcranial magnetic stimulation (TMS) of the human frontal cortex: implications for repetitive TMS treatment of depression

Transcranial magnetic stimulation (TMS) of the human frontal cortex: implications for repetitive TMS treatment of depression

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J Psychiatry Neurosci 2004;29(4):268-79

Tomáˇs Paus, MD, PhD; Jennifer Barrett, PhD

Montreal Neurological Institute, McGill University, Montréal, Que.

Abstract

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive tool used to manipulate activity in specific neural circuits of the human brain. Clinical studies suggest that, in some patients with major depression, rTMS has the potential to alleviate symptoms that may be related to functional abnormalities in a frontocingulate circuit. This paper reviews the rationale for the use of rTMS in this context. The following topics are discussed: symptoms and cognition in major depression, with special emphasis on the initiation of speech; neuroimaging studies of depression; rTMS as treatment for depression; structure and function of the mid-dorsolateral frontal and anterior cingulate cortices; and combined TMS/positron emission tomography studies of frontocortical connectivity.

Résumé

La stimulation magnétique transcrânienne répétitive (SMTr) est un outil non effractif utilisé pour manipuler l’activité de circuits neuraux précis du cerveau humain. Les études cliniques indiquent que chez certains patients aux prises avec une dépression majeure, la SMTr peut atténuer les symptômes pouvant être reliés à des anomalies fonctionnelles dans un circuit frontocingulaire. Cette communication passe en revue la justification de l’utilisation de la SMTr dans ce contexte. On aborde les sujets suivants : symptômes et cognition en cas de dépression majeure, avec accent sur l’initiation de la parole; étude de la dépression par neuro-imagerie; SMTr comme traitement de la dépression; structure et fonction des cortex cingulaires frontal et antérieur mésodorsolatéral; et étude de la connectivité frontocorticale par SMT et tomographie par émission de positrons combinées.


Medical subject headings: brain; cognition; depression; electroconvulsive therapy; frontal lobe; speech; tomography, emission computed; transcranial magnetic stimulation

Submitted July 4, 2003; Revised Feb. 6, 2004; Accepted Feb. 24, 2004

Acknowledgements: We thank our colleagues at the Montreal Neurological Institute for their contributions to the ongoing transcranial magnetic stimulation/positron emission tomography studies of cortical excitability and connectivity. Dr. Paus’s research is supported by the Canadian Institutes of Health Research, the Canadian Foundation for Innovation and the Natural Sciences and Engineering Research Council of Canada. Cadwell Laboratories Inc. and Rogue Research Inc. donated equipment and services to the laboratory.

Competing interests: None declared.

Correspondence to: Dr. Tomáˇs Paus, Cognitive Neuroscience Unit/Neuropsychology Department, Montreal Neurological Institute, 3801 University St., Montréal QC H3A 2B4; fax 514 398-1338; tomas@bic.mni.mcgill.ca