EEG Provides Insights Into Motor Control and Neuroplasticity During Stroke Recovery

Abstract

In many branches of medicine, treatment is guided by measuring its effects on underlying physiology. In this regard, the efficacy of rehabilitation/recovery therapies could be enhanced if their administration was guided by measurements that directly capture treatment effects on neural function. Measures of brain function via EEG may be useful toward this goal and have advantages such as ease of bedside acquisition, safety, and low cost. This review synthetizes EEG studies during the subacute phase poststroke, when spontaneous recovery is maximal, and focuses on movement. Event-related measures reflect cortical activation and inhibition, while connectivity measures capture the function of cortical networks. Several EEG-based measures are related to motor outcomes poststroke and warrant further evaluation. Ultimately, they may be useful for clinical decision-making and clinical trial design in stroke neurorehabilitation.

Keywords: biomarker; brain; clinical decision-making; electrophysiology; neurological rehabilitation; neuronal plasticity.

Figure 1:

Summary of studies examining ipsilesional cortical activity in subacute stroke during a motor task. All these studies observed decreased ipsilesional cortical activity compared to healthy controls, except where there is ^, representing a comparison with the contralesional hemisphere. The * represents significantly lower ipsilesional cortical during pre-movement and/or movement, as specified. Results are represented according to the time post-stroke (x-axis). Non-horizontal arrows represent significant within-subject longitudinal changes. Numbers represent the references associated with the results.

Figure 2:

Summary of the link between motor deficits and cortical coherence after stroke. Solid arrows represent a positive link between cortical coherence and motor performance, indicating that higher coherence levels are associated with better motor status, while dotted arrows represent a negative link between cortical coherence and motor performance, indicating that higher coherence levels are associated with poorer motor performance. The numbers are references associated with each result. aIPS=anterior Intraparietal Sulcus, M1=Primary Motor Cortex, PMC=Premotor Cortex, SMA=Supplementary Motor Area.