Bihemispheric brain stimulation facilitates motor recovery in chronic stroke patients

Abstract

Objective: Motor recovery after stroke depends on the integrity of ipsilesional motor circuits and interactions between the ipsilesional and contralesional hemispheres. In this sham-controlled randomized trial, we investigated whether noninvasive modulation of regional excitability of bilateral motor cortices in combination with physical and occupational therapy improves motor outcome after stroke. Methods:Twenty chronic stroke patients were randomly assigned to receive 5 consecutive sessions of either 1) bihemispheric transcranial direct current stimulation (tDCS) (anodal tDCS to upregulate excitability of ipsilesional motor cortex and cathodal tDCS to downregulate excitability of contralesional motor cortex) with simultaneous physical/occupational therapy or 2) sham stimulation with simultaneous physical/occupational therapy. Changes in motor impairment (Upper Extremity Fugl-Meyer) and motor activity (Wolf Motor Function Test) assessments were outcome measures while functional imaging parameters were used to identify neural correlates of motor improvement.

Multiple sessions of transcranial direct current stimulation and upper extremity rehabilitation in stroke: A review and meta-analysis

“…Combined over studies included in the meta-analysis, 164 (44%) participants had cortico-subcortical or cortical strokes and 49 (11%) participants had subcortical stroke. Three studies did not describe the location of the strokes (Lindenberg et al, 2010;Wu et al, 2013;Viana et al, 2014). Four studies involved 65 (18%) participants with chronic stroke (Lindenberg et al, 2010;Bolognini et al, 2011;Nair et al, 2011;Viana et al, 2014), four studies involved 263 (71%) participants in the sub-acute stage (Kim et al, 2010;Hesse et al, 2011;Wu et al, 2013;Lee and Chun, 2014) and one study involved 40 (11%) people with acute stroke (Khedr et al, 2013).…”

“…Four studies involved 65 (18%) participants with chronic stroke (Lindenberg et al, 2010;Bolognini et al, 2011;Nair et al, 2011;Viana et al, 2014), four studies involved 263 (71%) participants in the sub-acute stage (Kim et al, 2010;Hesse et al, 2011;Wu et al, 2013;Lee and Chun, 2014) and one study involved 40 (11%) people with acute stroke (Khedr et al, 2013). One hundred and forty-five (39%) participants had moderate UE impairments (Kim et al, 2010;Lindenberg et al, 2010;Bolognini et al, 2011;Nair et al, 2011;Lee and Chun, 2014;Viana et al, 2014) and 226 (61%) participants had severe UE impairments (Hesse et al, 2011;Khedr et al, 2013;Wu et al, 2013) at baseline based on the FMA or MRC Scale (shoulder) (Lum et al, 2002).…”

“…Eight studies used the FMA as an outcome measure of UE motor impairments (Kim et al, 2010;Lindenberg et al, 2010;Bolognini et al, 2011;Hesse et al, 2011;Nair et al, 2011;Wu et al, 2013;Lee and Chun, 2014;Viana et al, 2014) and one study used the Medical Research Council scale (Khedr et al, 2013). Only two studies explored the neurophysiological effects of tDCS, using measures of Resting and Active Motor Threshold (Khedr et al, 2013), motor evoked potential amplitude (Bolognini et al, 2011) and transcallosal inhibition to transcranial magnetic stimulation (Bolognini et al, 2011).…”

“…Only two studies explored the neurophysiological effects of tDCS, using measures of Resting and Active Motor Threshold (Khedr et al, 2013), motor evoked potential amplitude (Bolognini et al, 2011) and transcallosal inhibition to transcranial magnetic stimulation (Bolognini et al, 2011). Two studies employed functional MRI of brain activity as an outcome measure (Lindenberg et al, 2010;Nair et al, 2011). The Barthel Index or Modified Barthel Index and Motor Activity Log were utilised as measures of activities of daily living (Kim et al, 2010;Hesse et al, 2011;Bolognini et al, 2011;Khedr et al, 2013;Wu et al, 2013;Lee and Chun, 2014).…”

“…In stroke rehabilitation this means that researchers will employ anodal tDCS over the stroke hemisphere to improve the response of that hemisphere to training protocols (Hummel et al, 2005). Alternatively, employing the logic of inter-hemispheric imbalance, cathodal stimulation of the non-stroke hemisphere will inhibit that hemisphere to reduce its trans-hemispheric inhibition of the affected hemisphere or bihemispheric stimulation by simultaneously modulating the unaffected and affected motor cortex (Nitsche et al, 2003a;Lindenberg et al, 2010).…”