Repetitive transcranial magnetic stimulation and transcranial direct current stimulation in motor rehabilitation after stroke: An update

AbstractStroke is a leading cause of adult motor disability. The number of stroke survivors is increasing in industrialized countries, and despite available treatments used in rehabilitation, the recovery of motor functions after stroke is often incomplete. Studies in the 1980s showed that non-invasive brain stimulation (mainly repetitive transcranial magnetic stimulation [rTMS] and transcranial direct current stimulation [tDCS]) could modulate cortical excitability and induce plasticity in healthy humans. These findings have opened the way to the therapeutic use of the 2 techniques for stroke. The mechanisms underlying the cortical effect of rTMS and tDCS differ. This paper summarizes data obtained in healthy subjects and gives a general review of the use of rTMS and tDCS in stroke patients with altered motor functions. From 1988 to 2012, approximately 1400 publications were devoted to the study of non-invasive brain stimulation in humans. However, for stroke patients with limb motor deficit, only 141 publications have been devoted to the effects of rTMS and 132 to those of tDCS. The Cochrane review devoted to the effects of rTMS found 19 randomized controlled trials involving 588 patients, and that devoted to tDCS found 18 randomized controlled trials involving 450 patients. Without doubt, rTMS and tDCS contribute to physiological and pathophysiological studies in motor control. However, despite the increasing number of studies devoted to the possible therapeutic use of non-invasive brain stimulation to improve motor recovery after stroke, further studies will be necessary to specify their use in rehabilitation

Non-invasive brain stimulation in human stroke survivors

The use of electromagnetic currents toward understanding and curing human disease has long been of interest. In the 1980s, a dramatic increase in our understanding of brain function, along with parallel improvements in non-invasive brain stimulation (NIBS) technologies, subsequently caused rapid expansion of the field. Intraoperative monitoring techniques that incorporated single pulse stimulation were developed concurrently for the purpose of measuring corticospinal integrity (Merton & Morton, 1980a, 1980b); however, with the introduction of transcranial magnetic stimulation (TMS), the use of NIBS decisively exploded, opening a new window into the exploration and modulation of the brain (Barker and Jalinous, Lancet, 1(8437):1106–1107, 1985). Single pulse TMS, used initially to study inter-cortical physiology of the intact corticospinal tract, was thereafter investigated toward the rehabilitation of neurological and psychiatric conditions