TY - JOUR
T1 - Neurophysiological effects of mirror visual feedback in stroke patients with unilateral hemispheric damage
AU - Bartur, Gadi
AU - Pratt, Hillel
AU - Frenkel-Toledo, Silvi
AU - Soroker, Nachum
N1 - Publisher Copyright:
© 2018
PY - 2018/12/1
Y1 - 2018/12/1
N2 - Background and Objective: Mirror visual feedback (MVF; the illusory perception of movement in one hand upon viewing the moving opposite hand in a midsagittal mirror) is thought to facilitate restoration of mal-adaptive neurophysiological processes underlying conditions like complex regional pain syndrome and phantom limb pain, and to have a positive effect on brain plasticity processes underlying motor recovery after stroke. However, its exact mode of action remains unclear. The aim of the current study was to explore the immediate neurophysiological effects of MVF in patients with stroke-related hemiparesis. We also investigated how these effects relate to lesion location and extent. Method: EEG and EMG data were obtained from 14 first-event sub-acute stroke patients (8 with right-, 6 with left-hemiparesis) during repeated wrist extension movements of the Non-paretic Upper-Limb (NUL), without (NUL/M-) and with (NUL/M+) a midsagittal mirror, as well as during bilateral movements with a mirror (Bil/M+). EEG data was correlated with normalized lesion data obtained from follow-up CT scans. Results: NUL movement was accompanied by an asymmetric event-related de-synchronization (ERD) of low-beta EEG oscillations, with a more conspicuous ERD in the non-affected hemisphere. In the mirror condition, ERD magnitude was attenuated in both hemispheres. Stronger attenuation in the non-affected hemisphere abolished the hemispheric asymmetry. ERD attenuation by the mirror was affected by lesion side, the severity of hemiparesis and by lesion location and extent. Conclusion: Following hemispheric stroke, the magnitude of low-beta ERD accompanying unilateral movement of the non-involved upper limb, and its hemispheric asymmetry, are both reduced by MVF. Low-beta ERD dynamics may serve as a marker of neurophysiological response to MVF in research aimed to elucidate the factors influencing patients’ clinical gain from this treatment.
AB - Background and Objective: Mirror visual feedback (MVF; the illusory perception of movement in one hand upon viewing the moving opposite hand in a midsagittal mirror) is thought to facilitate restoration of mal-adaptive neurophysiological processes underlying conditions like complex regional pain syndrome and phantom limb pain, and to have a positive effect on brain plasticity processes underlying motor recovery after stroke. However, its exact mode of action remains unclear. The aim of the current study was to explore the immediate neurophysiological effects of MVF in patients with stroke-related hemiparesis. We also investigated how these effects relate to lesion location and extent. Method: EEG and EMG data were obtained from 14 first-event sub-acute stroke patients (8 with right-, 6 with left-hemiparesis) during repeated wrist extension movements of the Non-paretic Upper-Limb (NUL), without (NUL/M-) and with (NUL/M+) a midsagittal mirror, as well as during bilateral movements with a mirror (Bil/M+). EEG data was correlated with normalized lesion data obtained from follow-up CT scans. Results: NUL movement was accompanied by an asymmetric event-related de-synchronization (ERD) of low-beta EEG oscillations, with a more conspicuous ERD in the non-affected hemisphere. In the mirror condition, ERD magnitude was attenuated in both hemispheres. Stronger attenuation in the non-affected hemisphere abolished the hemispheric asymmetry. ERD attenuation by the mirror was affected by lesion side, the severity of hemiparesis and by lesion location and extent. Conclusion: Following hemispheric stroke, the magnitude of low-beta ERD accompanying unilateral movement of the non-involved upper limb, and its hemispheric asymmetry, are both reduced by MVF. Low-beta ERD dynamics may serve as a marker of neurophysiological response to MVF in research aimed to elucidate the factors influencing patients’ clinical gain from this treatment.
KW - EEG
KW - Event related de-synchronization
KW - Inter-hemispheric dynamics
KW - Mirror visual feedback
KW - Stroke rehabilitation
UR - http://www.scopus.com/inward/record.url?scp=85053218786&partnerID=8YFLogxK
U2 - 10.1016/j.brainres.2018.09.003
DO - 10.1016/j.brainres.2018.09.003
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C2 - 30194016
AN - SCOPUS:85053218786
SN - 0006-8993
VL - 1700
SP - 170
EP - 180
JO - Brain Research
JF - Brain Research
ER -