Brain Symmetry Index in Healthy and Stroke Patients for Assessment and Prognosis.

Andrei Agius Anastasi,Malcolm Vella,Kenneth Camilleri,Owen Falzon,Richard Muscat

doi:10.1155/2017/8276136

Andrei Agius Anastasi, Malcolm Vella + Show 3 more

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https://doi.org/10.1155/2017/8276136

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Abstract

Objective. Quantitative neurophysiological signal parameters are of value in predicting motor recovery after stroke. The novel role of EEG-derived brain symmetry index for motor function prognostication in the subacute phase after stroke is explored. Methods. Ten male stroke patients and ten matched healthy controls were recruited. Motor function was first assessed clinically using the MRC score, its derivative Motricity Index, and the Fugl–Meyer assessment score. EEG was subsequently recorded first with subjects at rest and then during hand grasping motions, triggered by visual cues. Brain symmetry index (BSI) was used to identify the differences in EEG-quantified interhemispheric cortical power asymmetry observable in healthy versus cortical and subcortical stroke patients. Subsequently, any correlation between BSI and motor function was explored. Results. BSI was found to be significantly higher in stroke subjects compared to healthy controls (p = 0.023). The difference in BSI was more pronounced in the cortical stroke subgroup (p = 0.016). BSI showed only a mild general decrease on repeated monthly recording. Notably, a statistically significant correlation was observed between early BSI and Fugl–Meyer score later in recovery (p < 0.050). Conclusions. Brain symmetry index is increased in the subacute poststroke phase and correlates with motor function 1-2 months after stroke.

Highlights

Stroke is one of the leading causes of physical disability in adulthood, with more than a third of the 15 million yearly stroke sufferers being left with permanent disability [1]
This study successfully presents a very strong correlation between the Fugl–Meyer and the Medical Research Council (MRC) score, along with its derivative, the Motricity Index
Correlation between clinical scores and neurophysiological signal parameters was stronger with Fugl–Meyer than with MRC and Motricity Index scores, reflecting the more detailed and accurate nature of the Fugl–Meyer over the other two time-efficient bedside scores

Summary

Introduction

Stroke is one of the leading causes of physical disability in adulthood, with more than a third of the 15 million yearly stroke sufferers being left with permanent disability [1]. Assessment of deficit and residual motor function in the clinical field is often restricted to bedside examination. The Medical Research Council (MRC) 0-to-5 scale muscle power assessment tool, originally designed for peripheral neuromuscular disorders, is one of the most ubiquitously used tools for motor power assessment in the clinical field [2]. Prognostication of recovery is often based on the more simple bedside examination, along with the size of infarct on CT and MR imaging of the brain [5, 6]. Such benchmarks are often prone to interassessor variability and bias [2]

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