Bilateral Contralaterally Controlled Functional Electrical Stimulation Reveals New Insights Into the Interhemispheric Competition Model in Chronic Stroke

Abstract

Background. Upper-limb chronic stroke hemiplegia was once thought to persist because of disproportionate amounts of inhibition imposed from the contralesional on the ipsilesional hemisphere. Thus, one rehabilitation strategy involves discouraging engagement of the contralesional hemisphere by only engaging the impaired upper limb with intensive unilateral activities. However, this premise has recently been debated and has been shown to be task specific and/or apply only to a subset of the stroke population. Bilateral rehabilitation, conversely, engages both hemispheres and has been shown to benefit motor recovery. To determine what neurophysiological strategies bilateral therapies may engage, we compared the effects of a bilateral and unilateral based therapy using transcranial magnetic stimulation. Methods. We adopted a peripheral electrical stimulation paradigm where participants received 1 session of bilateral contralaterally controlled functional electrical stimulation (CCFES) and 1 session of unilateral cyclic neuromuscular electrical stimulation (cNMES) in a repeated-measures design. In all, 15 chronic stroke participants with a wide range of motor impairments (upper extremity Fugl-Meyer score: 15 [severe] to 63 [mild]) underwent single 1-hour sessions of CCFES and cNMES. We measured whether CCFES and cNMES produced different effects on interhemispheric inhibition (IHI) to the ipsilesional hemisphere, ipsilesional corticospinal output, and ipsilateral corticospinal output originating from the contralesional hemisphere. Results. CCFES reduced IHI and maintained ipsilesional output when compared with cNMES. We found no effect on ipsilateral output for either condition. Finally, the less-impaired participants demonstrated a greater increase in ipsilesional output following CCFES. Conclusions. Our results suggest that bilateral therapies are capable of alleviating inhibition on the ipsilesional hemisphere and enhancing output to the paretic limb.

Effectiveness of Contralaterally Controlled Functional Electrical Stimulation versus Neuromuscular Electrical Stimulation on Upper Limb Motor Functional Recovery in Subacute Stroke Patients: A Randomized Controlled Trial

“…And compared with coupled bilateral movement and placebo stimulation, coupled bilateral movement and FES had better effect on improvement of functional test of upper limb and active range of wrist extension [ 26 , 27 ]. A recent crossover study showed that CCFES (bilateral symmetric movement) reduced interhemispheric inhibition and maintained ipsilesional output when compared with NMES (unilateral-based therapy) [ 28 ]. Besides, the intention-to-control mode of stimulation offered by CCFES enables patients who have no or fewer residual motor function of affected limb to do functional-related repetitive training.…”

Bilateral Transcutaneous Electrical Nerve Stimulation Improves Upper Limb Motor Recovery in Stroke: A Randomized Controlled Trial

“…First, Bi-TENS could enhance interactions between the intact and lesioned hemispheres via the transcallosal pathway that connects the two cerebral hemispheres. 26 Cunningham et al 15 found that 60 minutes of bilateral functional electrical stimulation over paretic extensor digitorum communis and extensor pollicis longus muscles could reduce interhemispheric inhibition but that unilateral stimulation did not. Reducing interhemispheric inhibition with Bi-TENS helps reinforce the interhemispheric interaction via the transcallosal pathway and enhances the motor recovery of paretic upper limb.…”

Effectiveness of a Novel Contralaterally Controlled Neuromuscular Electrical Stimulation for Restoring Lower Limb Motor Performance and Activities of Daily Living in Stroke Survivors: A Randomized Controlled Trial

“…Activity in the contralesional hemisphere is likely to contribute to motor function recovery after stroke via a small proportion (10%) of the pyramidal tract that did not decussate [ 35 ]. Cunningham et al showed that this type of bilateral neuromuscular electrical stimulation can reduce the interhemispheric inhibition from unaffected motor cortices and maintain the ipsilesional output to the paretic limb [ 36 ]. This indicates that bilateral and unilateral electrical stimulation act through different neurophysiological mechanisms in stroke participants and that CCNMES has the potential to promote the recovery of paretic limbs through symmetric bilateral movement, which reduces inhibition between the bilateral hemispheres.…”