Advances in brain stimulation techniques

Aims: To critically review the exciting recent advances in new, minimally invasive brain stimulation (MIBS) techniques. Particular attention will focus on their potential antidepressant effects, ability to be coupled with functional brain imaging techniques, and known neurobiological mechanisms of action.

Methods: The current MIBS renaissance builds on recent knowledge from the field of functional brain imaging, as well as classic teachings from neuropsychiatry. The past decade has seen fundamental advances in the following MIBS techniques: transcranial magnetic stimulation (TMS), vagus nerve stimulation (VNS), conventional electroconvulsive therapy (ECT) (now modified and produced by magnetic currents: (magnetic seizure therapy (MST)), and finally, deep brain stimulation (DBS). Antidepressant clinical trial data will be reviewed for each technique, as well as data from their combination with functional brain imaging.

Conclusions: These tools hold the promise of a new age for neuropsychiatry, from both a research and clinical perspective. As research tools, MIBS techniques can formally test hypotheses about brain-behaviour relations. Although still crude clinically, several of the techniques have shown early promise, particularly in the area of depression. Unfortunately, rapid clinical progress is hampered by incomplete understanding of the effects of brain stimulation at a cellular, neurotransmitter, or genetic level, particularly as function of stimulation use parameters (frequency, intensity, pulse width, duty cycle, and dose). Nevertheless, these advances suggest that perhaps the real golden age of neuropsychiatry was not during the time of Ferrier, Jackson, and Gowers. Rather, armed with advanced brain scans and MIBS tools (and full knowledge of their neurobiological effects), neuropsychiatrists of the near future will be able to use MIBS techniques to research and probe the normal human brain and then to correct its dysfunctions.

Transcranial magnetic stimulation of the brain: mechanisms and application

Aims: To understand more about the physiological mechanism(s) responsible for long term effects of repetitive transcranial magnetic stimulation (rTMS) on the human cerebral cortex.

Methods: …