Bilateral Mechanoreception Discrimination based on Bihemispheric Somatosensory Response Patterns is Associated with...

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Biomedical Engineering

Background:

• Stroke frequently impairs proprioception and motor control, with underlying cortical sensory changes not fully understood.
• Previous studies focused on unilateral responses, potentially missing crucial bilateral sensory processing details relevant to recovery.

Purpose of the Study:

• To investigate bilateral cortical sensory responses to vibrotactile stimulation in stroke survivors.
• To determine the relationship between these sensory responses and proprioceptive and motor function.

Main Methods:

• Recorded EEG from 46 chronic stroke individuals during fingertip vibrotactile stimulation.
• Quantified somatosensory evoked potentials (SEPs) and event-related desynchronization (ERD).
• Assessed finger proprioception and motor function using standardized tests; analyzed associations with unilateral responses and a somatosensory decoder.

Main Results:

• Reduced ipsilesional SEPs and ERD were observed when stimulating the paretic hand.
• Lower SEP magnitude and sensory decoder performance correlated with poorer proprioception.
• Somatosensory decoder performance, unlike unilateral responses, significantly predicted motor function (explaining ~22.5% of variance).

Conclusions:

• The hemispheric distribution and discriminability of cortical sensory responses are key indicators of sensorimotor function post-stroke.
• Bilateral sensory response analysis, particularly using decoding, may offer superior insights into stroke recovery compared to unilateral measures.
• Decoding-based neurophysiological measures show promise for rehabilitation, biomarker development, and patient stratification.