β-Oscillations Reflect Recovery of the Paretic Upper Limb in Subacute Stroke

Abstract

Background. Recovery of upper limb function post-stroke can be partly predicted by initial motor function, but the mechanisms underpinning these improvements have yet to be determined. Here, we sought to identify neural correlates of post-stroke recovery using longitudinal magnetoencephalography (MEG) assessments in subacute stroke survivors. Methods. First-ever, subcortical ischemic stroke survivors with unilateral mild to moderate hand paresis were evaluated at 3, 5, and 12 weeks after stroke using a finger-lifting task in the MEG. Cortical activity patterns in the β-band (16-30 Hz) were compared with matched healthy controls. Results. All stroke survivors (n=22; 17 males) had improvements in action research arm test (ARAT) and Fugl-Meyer upper extremity (FM-UE) scores between 3 and 12 weeks. At 3 weeks post-stroke the peak amplitudes of the movement-related ipsilesional β-band event-related desynchronization (β-ERD) and synchronization (β-ERS) in primary motor cortex (M1) were significantly lower than the healthy controls (p<0.001) and were correlated with both the FM-UE and ARAT scores (r=0.51-0.69, p<0.017). The decreased β-ERS peak amplitudes were observed both in paretic and non-paretic hand movement particularly at 3 weeks post-stroke, suggesting a generalized disinhibition status. The peak amplitudes of ipsilesional β-ERS at week 3 post-stroke correlated with the FM-UE score at 12 weeks (r=0.54, p=0.03) but no longer significant when controlling for the FM-UE score at 3 weeks post-stroke. Conclusions. Although early β-band activity does not independently predict outcome at 3 months after stroke, it mirrors functional changes, giving a potential insight into the mechanisms underpinning recovery of motor function in subacute stroke.

Motor beta cortical oscillations are related with the gait kinematics of youth with cerebral palsy

“…[56][57][58] Furthermore, prior MEG studies have also identified that, when compared with controls, the sensorimotor beta cortical oscillations are also abnormal in individuals that have incurred a stroke, although the directionality of the differences in beta oscillatory strength have been mixed (i.e., stronger vs. weaker) across the respective studies. [59][60][61][62] Nevertheless, we suggest care should be taken in linking our results in CP to observations in the stroke literature, as the neural injuries in those who incurred a stroke generally occur in the less plastic adult brain, while those seen in CP generally occurred in the highly plastic perinatal de novo brain. The enormous capacity for neuroplasticity in the developing brain obviously raises challenges in making direct comparisons.…”

The Impact of Electroacupuncture at Hegu, Shousanli, and Quchi Based on the Theory “Treating Flaccid Paralysis by Yangming Alone” on Stroke Patients’ EEG: A Pilot Study

“…In the current study, EA treatment was found to induce modulation of beta and delta band power from the ipsilesional and contralesional primary motor cortex of stroke patients while, in our previous study, we found that Jin's three-needle acupuncture therapy (an empiric treatment) could induce alpha rhythm oscillations from the occipital and parietal areas [ 28 ]. As we know, beta-band power oscillations within the primary motor cortex (M1) were reported to be linked to upper limb motor recovery in many studies [ 19 , 29 , 30 ]. Previous research also suggested delta band power in M1 was related to a better motor status [ 21 , 31 ].…”

The effect of alertness and attention on the modulation of the beta rhythm to tactile stimulation

“…These findings support the reliability of group-level findings of changes in beta suppression/ rebound, that is, in different clinical conditions. Especially the minimal effect of reduced alertness on the strength of beta rebound is important, as the beta rebound has been suggested as a biomarker of the functional state of the SMI cortex after stroke (Laaksonen et al, 2012;Parkkonen et al, 2017Parkkonen et al, , 2018Tang et al, 2020). However, at the individual level, alterations in alertness may affect beta rhythm modulation, especially beta suppression, which should be taken into account in longitudinal experiments to avoid misinterpretations.…”

“…The beta rebound has been proposed to reflect the functional state of the SMI cortex in various neurological diseases such as stroke (Laaksonen et al, 2012;Parkkonen et al, 2017;Tang et al, 2020), schizophrenia (Brookes et al, 2015;Liddle et al, 2016), Parkinson's disease (Degardin et al, 2009;Hall et al, 2014;Vinding et al, 2019), and cerebral palsy (Demas et al, 2019;Pihko et al, 2014). However, patients are prone to changes in their alertness during MEG/EEG recordings, which may alter the oscillatory activity, and thus potentially affect the estimated cortical level of excitability.…”