Effects of Combined Peripheral Nerve Stimulation and Brain Polarization on Performance of a Motor Sequence Task After Chronic Stroke

Abstract

Background and Purpose-Recent work demonstrated that application of peripheral nerve and cortical stimulation independently can induce modest improvements in motor performance in patients with stroke. The purpose of this study was to test the hypothesis that combining peripheral nerve stimulation (PNS) to the paretic hand with anodal direct current stimulation (tDCS) to the ipsilesional primary motor cortex (M1)

Bihemispheric brain stimulation facilitates motor recovery in chronic stroke patients

“…Previous unihemispheric brain stimulation studies revealed transient beneficial effects after modulation of either ipsilesional 7,10,11,14 or contralesional motor cortex excitability. 9,12 The novel bihemispheric stimulation design used in the present study allowed us to test the efficacy of simultaneously affecting both components of the hypothesized imbalance of interhemispheric interactions after stroke.…”

“…Furthermore, the multisession design of the present study cannot be easily related to previous single session experiments of chronic stroke patients. 11,12,14 To adequately compare the efficacy of different tDCS montages in combination with peripheral sensorimotor stimulation and to assess differences in short-term and longer-term functional improvements, larger patient samples are needed. Furthermore, although we chose to combine tDCS with PT/OT, which is commonly applied in routine poststroke rehabilitation, more standardized peripheral stimulation programs such as constraintinduced movement therapy may be an alternative in future studies.…”

“…5,6 The model of interhemispheric imbalance provides a framework for developing hypotheses based on its 2 facets: 1) upregulating excitability of intact portions of the ipsilesional motor cortex and 2) downregulating excitability of the contralesional motor cortex to modulate its unrestrained inhibitory influence on ipsilesional regions. 2,4 Pilot and proof-ofprinciple studies, using either rTMS [7][8][9][10] or tDCS, [11][12][13][14] have shown both approaches to have beneficial effects on motor skills and motor learning. Furthermore, the combination of tDCS and peripheral stimulation (e.g., peripheral nerve stimulation or peripheral sensorimotor activities) seems to enhance the effects of each intervention by itself.…”

“…Furthermore, the combination of tDCS and peripheral stimulation (e.g., peripheral nerve stimulation or peripheral sensorimotor activities) seems to enhance the effects of each intervention by itself. 13,14 To date, however, no study has tested the efficacy of bihemispheric stimulation, i.e., upregulation of ipsilesional and simultaneous downregulation of contralesional motor regions, in combination with peripheral sensorimotor activities in chronic stroke patients. Bihemispheric tDCS may potentiate the effects of anodal stimulation to the lesional hemisphere 11,14 through additional modulation of interhemispheric interactions 15 via cathodal stimulation to the contralesional motor cortex.…”

Neurophysiological basis of a new electrode configuration to potentiate the tDCS: Protocols for upper limbs

“…In fact, the association of tDCS with peripheral nerve electrical stimulation, aerobic exercise or conventional physiotherapy improves pain and motor function in a more pronounced way than these interventions per se [8][9][10][11][12][13] . These results have been interpreted on the basis of the meta plasticity phenomenon 14 .…”