Optimizing recovery potential through simultaneous occupational therapy and non-invasive brain-stimulation using tDCS

Abstract

Purpose It is thought that following a stroke the contralesional motor region exerts an undue inhibitory influence on the lesional motor region which might limit recovery. Pilot studies have shown that suppressing the contralesional motor region with cathodal transcranial Direct Current Stimulation (tDCS) can induce a short lasting functional benefit; greater and longer lasting effects might be achieved with combining tDCS with simultaneous occupational therapy (OT) and applying this intervention for multiple sessions. Methods We carried out a randomized, double blind, sham controlled study of chronic stroke patients receiving either 5 consecutive days of cathodal tDCS (for 30 minutes) applied to the contralesional motor region and simultaneous OT, or sham tDCS+OT. Results We showed that cathodal tDCS+OT resulted in significantly more improvement in Range-Of-Motion in multiple joints of the paretic upper extremity and in the Upper-Extremity Fugl-Meyer scores than sham tDCS+OT, and that the effects lasted at least one week post-stimulation. Improvement in motor outcome scores was correlated with decrease in fMRI activation in the contralesional motor region exposed to cathodal stimulation. Conclusions This suggests that cathodal tDCS combined with OT leads to significant motor improvement after stroke due to a decrease in the inhibitory effect that the contralesional hemisphere exerts onto the lesional hemisphere.

Effect of a contralateral lesion on neurological recovery from stroke in rats

“…Our results are consistent with several previous experimental (Allred et al, 2010; Rha et al, 2011; Zhao et al, 2009) and clinical (Boggio et al, 2007; Bradnam et al, 2011; Kang et al, 2011; Nair et al, 2011) studies, in which attenuating the effect of the contralesional hemisphere improved functional motor recovery after brain infarction. However, other experimental (Jin et al, 2011; Napieralski et al, 1998; Shanina et al, 2006) and clinical (Takeuchi et al, 2012) stroke studies have yielded opposite conclusions.…”

Transcranial Direct Current Stimulation Post-Stroke Upper Extremity Motor Recovery Studies Exhibit a Dose–Response Relationship

“…We used random-effects model to account for this duplication (between-study variance τ 2 = 0.46; heterogeneity index I 2 = 71%). We grouped individual studies based on tDCS montage as anodal [24,25,28], cathodal [23–25,27] or bihemispheric [22,26,29] (Fig. 2A) as well as based on the mean post-stroke duration as acute stroke [23–25,28] or chronic stroke [22,26,27,29] (mean time post-stroke ≤1 month or ≥2.5 years, respectively; Fig.…”

Stimulation targeting higher motor areas in stroke rehabilitation: A proof-of-concept, randomized, double-blinded placebo-controlled study of effectiveness and underlying mechanisms

“…The effect of stimulation was not apparent across individuals with severe impairments who suffered from greater damage to CST from M1. Since the completion of the trial, several groups have continued to report no benefit of the classical approach (Hesse et al, 2011; Seniow et al, 2012; Talelli et al, 2012) even as others have evidenced a promising 5–6-point advantage in UEFM (Bolognini et al, 2011; Lindenberg, Renga, Zhu, Nair, & Schlaug, 2010; Nair, Renga, Lindenberg, Zhu, & Schlaug, 2011). Although, preliminary, we show that 5 of the 6 patients receiving facilitation to the ipsilesional premotor areas achieved clinically important gains ranging between 5 to 14-point increase in UEFM.…”

“…Earlier studies have emphasized a competitive role of the contralesional hemisphere (Marshall et al, 2000; Murase et al, 2004; N. S. Ward, Brown, Thompson, & Frackowiak, 2003a), seeking to decrease its excitability, hence its ability to overly-inhibit the ipsilesional hemisphere (Nair et al, 2011). However, controversy surfaced when studies with fMRI showed a greater shift in cortical activation to the contralesional hemisphere with greater gains after rehabilitative therapy (Cramer et al, 1997; Johansen-Berg, Dawes, et al, 2002).…”