Study of Repetitive Movements Induced Oscillatory Activities in Healthy Subjects and Chronic Stroke Patients

Abstract

Repetitive movements at a constant rate require the integration of internal time counting and motor neural networks. Previous studies have proved that humans can follow short durations automatically (automatic timing) but require more cognitive efforts to track or estimate long durations. In this study, we studied sensorimotor oscillatory activities in healthy subjects and chronic stroke patients when subjects were performing repetitive finger movements. We found the movement-modulated changes in alpha and beta oscillatory activities were decreased with the increase of movement rates in finger lifting of healthy subjects and the non-paretic hands in stroke patients, whereas no difference was found in the paretic-hand movements at different movement rates in stroke patients. The significant difference in oscillatory activities between movements of non-paretic hands and paretic hands could imply the requirement of higher cognitive efforts to perform fast repetitive movements in paretic hands. The sensorimotor oscillatory response in fast repetitive movements could be a possible indicator to probe the recovery of motor function in stroke patients.

Effective assessments of electroencephalography during stroke recovery: contemporary approaches and considerations

“…It is known that during the acute stages of stroke, spatiotemporal abnormalities of delta waves are prominent across brain regions and are generally present following an ischemic stroke. Delta foci (1-3 Hz), which are typically slow, highamplitude oscillatory waves, highly correlate with stroke lesion locations, as confirmed via later neuroimaging (Finnigan and van Putten 2013). Furthermore, a recent study by demonstrated the prognostic utility of delta/alpha ratios (ratio of absolute power within a frequency band), which when coupled with findings of attenuation to alpha power (8 -12 Hz) provide more defined indices of slowing EEG.…”

“…Recent techniques for analyzing EEG during acute stages of stroke have improved upon established methods of the past (Finnigan and van Putten 2013), allowing a deeper understanding of cortical activity and connectivity changes following brain injury.…”

“…Over the past two decades, several analyses of stroke EEG have progressed from a conventional neurological (manual) scoring of data to the use of quantitative techniques that provide more rapid and robust metric-based indices of injury and recovery poststroke. Examples of quantified EEG, such as frequency spectrum analyses, have thus substantially improved interpretation of conventional EEG, allowing for better clinical categorization of stroke severity with respect to brain function (Finnigan and van Putten 2013). Quantitative EEG analyses of stroke have also been further refined over time and now critically integrate brain connectivity techniques (Auriat et al 2015;Ward 2015), which have provided a renewed focus on the robust characterization of whole-brain connectivity between lesion and perilesional areas poststroke.…”

“…Current evidence in the acute phase (6 to 24 h poststroke) suggests that quantifying changes in slow and fast frequency bands are potentially strong indicators of clinical outcomes, such as severity of injury and likelihood for recovery (Caliandro et al 2017;Wu et al 2016). As stroke progresses to more subacute and chronic stages (within days postinjury to greater than 3 mo), whole brain (functional) connectivity measures such as the application of phase synchrony and graph theoretic measures (Borich et al 2016;Hsu et al 2016;Nicolo et al 2015), become more important in addressing how the brain reorganizes neural connections between stroke-affected and unaffected brain regions, particularly as patients show progress toward functional recovery. Parallel to the application of these techniques is the emergence of multimodal (neuroimaging and EEG) monitoring following stroke in an effort to achieve more targeted, individually tailored neurorehabilitation paradigms (Auriat et al 2015).…”

“…Parallel to the application of these techniques is the emergence of multimodal (neuroimaging and EEG) monitoring following stroke in an effort to achieve more targeted, individually tailored neurorehabilitation paradigms (Auriat et al 2015). This review article highlights several recent reports (Borich et al 2016;Caliandro et al 2017;Hsu et al 2016;Mrachacz-Kersting et al 2016;Nicolo et al 2015;Wu et al 2016) to discuss the vital role of effectively quantifying EEG in informing stroke-neurorehabilitation paradigms and improving future poststroke assessments.…”