P 69 Assessing the relation between brain structure and function during motor imagery in stroke patients and controls using EEG and MRI

摘要

Background Motor imagery (MI) training, in particular in combination with EEG-based neurofeedback (MI-NF), has been suggested as a potential add-on therapy for rehabilitation of upper limb motor impairments after stroke. Most MI-NF implementations are based on the event-related desynchronization (ERD) in the 8–30 Hz frequency range that is typically observed over sensorimotor areas during motor execution and imagination. The amplitude and consistency of the ERD depends, among other things, on brain structure and function during motor imagery (e.g., ). Because the vast majority of the research on MI-NF has been conducted with young healthy individuals, it is unclear to what degree changes regarding the relationship between MI-induced ERD, MI-induced functional magnetic resonance imaging (fMRI) activation and brain structure in stroke patients are due to normal aging and the stroke, respectively. Objectives (1) to investigate in healthy older adults (45 years) associations of MI-induced ERD, MI-induced fMRI activation and diffusion tensor imaging (DTI) measures, and (2) to investigate differences in these measures between chronic stroke patients and healthy older adults matched for age and gender. Methods We included 12 chronic stroke patients with residual upper limb motor impairment (mean age 61.5 years – range 49–75 years; 3 females) and 17 healthy older adults (mean age 60.4 years – range 48–77 years; 9 females). All participants completed a 3T MRI session and a 96-electrode EEG session. The MRI session included a high-resolution anatomical scan, DTI, and fMRI during rest, motor execution and kinesthetic MI of repeated hand opening and closing. The EEG session consisted of three blocks: motor execution, kinesthetic MI and kinesthetic MI with real-time EEG-based visual feedback, all with the same hand movement as during fMRI. Each patient also completed a motor assessment consisting of the upper limb section of the Fugl-Mayer Assessment and the Modified Ashworth Scale. Results We will present preliminary results regarding the correlations of ERD and fMRI activation related to motor execution and imagination. Moreover, we will present the results of a replication of the analysis of that for young healthy adults indicated a significant association between MI-induced ERD and white matter integrity (fractional anisotropy) in subcortical structures. ]]>