EEG Correlates of Upper Limb Function During the Box and Block Test After Stroke

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Biomedical Engineering

Background:

• Upper limb motor impairment is common after stroke, necessitating objective assessment for effective rehabilitation.
• Current clinical tools like the Box and Block Test (BBT) lack detailed insights into motor control processes.
• Integrating biosignals with neurorehabilitation technologies requires advanced assessment methods.

Purpose of the Study:

• To investigate the feasibility of using electroencephalography (EEG) during an adapted BBT for motor assessment in stroke survivors.
• To identify EEG-based markers reflecting motor and motor planning processes during a functional task.
• To explore the potential of EEG-derived features for characterizing post-stroke upper limb function.

Main Methods:

• Fifteen healthy individuals and eleven stroke survivors performed an EEG-adapted BBT.
• Simultaneous recording of electroencephalographic (EEG), kinematic, and behavioral data.
• Computation of event-related desynchronization/synchronization (ERD/ERS) in alpha, beta, and gamma bands during task phases.

Main Results:

• Stroke patients showed reduced medial-frontal desynchronization during block handling compared to controls.
• Beta-band ERD over sensorimotor areas positively correlated with Fugl-Meyer Assessment scores.
• Phase-classification analysis using ERD/ERS features achieved high discrimination (AUC up to 0.86), though reduced for the affected limb in stroke survivors.

Conclusions:

• Phase-resolved EEG analysis is feasible during complex functional tasks like the BBT.
• EEG-derived markers show promise for detailed characterization of post-stroke upper limb motor function.
• This approach could enhance the integration of biosignal feedback in neurorehabilitation.