Non-Invasive Brain Stimulation: An Interventional Tool for Enhancing Behavioral Training after Stroke

Abstract

Stroke is the leading cause of disability among adults. Motor deficit is the most common impairment after stroke. Especially, deficits in fine motor skills impair numerous activities of daily life. Re-acquisition of motor skills resulting in improved or more accurate motor performance is paramount to regain function, and is the basis of behavioral motor therapy after stroke. Within the past years, there has been a rapid technological and methodological development in neuroimaging leading to a significant progress in the understanding of the neural substrates that underlie motor skill acquisition and functional recovery in stroke patients. Based on this and the development of novel non-invasive brain stimulation (NIBS) techniques, new adjuvant interventional approaches that augment the response to behavioral training have been proposed. Transcranial direct current, transcranial magnetic, and paired associative (PAS) stimulation are NIBS techniques that can modulate cortical excitability, neuronal plasticity and interact with learning and memory in both healthy individuals and stroke patients. These techniques can enhance the effect of practice and facilitate the retention of tasks that mimic daily life activities. The purpose of the present review is to provide a comprehensive overview of neuroplastic phenomena in the motor system during learning of a motor skill, recovery after brain injury, and of interventional strategies to enhance the beneficial effects of customarily used neurorehabilitation after stroke.

Emergent properties of neural repair: elemental biology to therapeutic concepts

“…Unlike the pharmacological manipulation of tonic GABA in rodent models of stroke, which specifically manipulate excitatory neurons and preferentially those that have been impacted by stroke,5 tDC and TMS more grossly affect all of the brain tissue in the electrical or magnetic field, and induce many distinct types of cortical circuits 55. Nonetheless, small‐scale studies indicate that excitatory tDC or TMS over the ipsilesional hemisphere in stroke, or inhibitory tDC over the contralateral hemisphere, may improve recovery after stroke 55. Larger‐scale trials are under way for this application 56, 57…”

Cerebellar transcranial static magnetic field stimulation transiently reduces cerebellar brain inhibition

“…Non-invasive brain stimulation techniques are frequently used and studied for their potential applications in physical medicine and rehabilitation (Hoyer and Celnik, 2011;Adeyemo et al, 2012;Wessel et al, 2015). However, rTMS and tDCS are not comfortable for subjects submitted to these techniques (Hardwick et al, 2014).…”

A proof-of-concept study on the combination of repetitive transcranial magnetic stimulation and relaxation techniques in chronic tinnitus

“…A combination of behavioral training and non-invasive brain stimulation was also shown to present a new adjuvant in the treatment of neurological patients after brain injury (Wessel et al 2015). Using transcrancial direct current stimulation (tDCS), it could recently be demonstrated that episodic memory retrieval is dependent from activity during the encoding phase (Zwissler et al 2014) and that cognitive training of working memory is superior if applied ''online'' (tDCS during performance) in contrast to priming (tDCS before performance) (Martin et al 2014).…”