Based on the available evidence , motor evoked potentials at rest were the only biomarker that predicted motor outcome in individuals with severe arm impairment following stroke .
To build an underst and ing of the neurobiology underpinning arm recovery in people with severe arm impairment due to stroke , we conducted a pooled individual data systematic review to : 1 ) characterize brain biomarkers ; 2 ) determine relationship(s ) between biomarkers and motor outcome ; and 3 ) establish relationship(s ) between biomarkers and motor recovery .
Efficacy of EMG-triggered electrical arm stimulation in chronic hemiparetic stroke patients.
PURPOSE EMG-triggered electrostimulation ( EMG-ES ) may improve the motor performance of affected limbs of hemiparetic stroke patients even in the chronic stage . This study was design ed to characterize cortical activation changes following intensified EMG-ES in chronic stroke patients and to identify predictors for successful rehabilitation depending on disease severity . METHODS We studied 9 patients with severe residual hemiparesis , who underwent 8 weeks of daily task-orientated multi-channel EMG-ES of the paretic arm .  Before and after treatment , arm function was evaluated clinical ly and cortical activation patterns were assessed with functional MRI ( fMRI ) and /or transcranial magnetic stimulation ( TMS ) . RESULTS As response to therapy , arm function improved in a subset of patients with more capacity in less affected subjects , but there was no significant gain for those with Box & Block test values below 4 at inception . The clinical improvement , if any , was accompanied by an ipsilesional increase in the sensorimotor cortex ( SMC ) activation area in fMRI and enhanced intracortical facilitation ( ICF ) as revealed by paired TMS . The SMC activation change in fMRI was predicted by the presence or absence of motor-evoked potentials ( MEPs ) on the affected side . CONCLUSIONS The present findings support the notion that intensified EMG-ES may improve the arm function in individual chronic hemiparetic stroke patients but not in more severely impaired individuals . Functional improvements are paralleled by increased ipsilesional SMC activation and enhanced ICF supporting neuroplasticity as contributor to rehabilitation . The clinical score at inception and the presence of MEPs have the best predictive potential
Based on the available evidence , motor evoked potentials at rest were the only biomarker that predicted motor outcome in individuals with severe arm impairment following stroke .
To build an underst and ing of the neurobiology underpinning arm recovery in people with severe arm impairment due to stroke , we conducted a pooled individual data systematic review to : 1 ) characterize brain biomarkers ; 2 ) determine relationship(s ) between biomarkers and motor outcome ; and 3 ) establish relationship(s ) between biomarkers and motor recovery .