Neuroengineering approaches assessing structural and functional changes of motor descending pathways in stroke.

Stroke is a leading cause of adult disability worldwide, with approximately 101 million survivors globally. Over 60% of these individuals live with from long-term, often lifelong, movement impairments that significantly hinder their ability to perform essential daily activities and maintain independence. Post-stroke movement disabilities are highly associated with structural and functional changes in motor descending pathways, particularly the corticospinal tract (CST) and other indirect motor pathways via the brainstem.

The Role of Hemispheric Sensory Shifts: Impacts on Stretch Reflex and Motor Plasticity Post-Stroke.

Previous studies have found that post-stroke motor impairments are associated with damage to the lesioned corticospinal tract and the hyperexcitability of the cortico-reticulospinal tract at the hemisphere opposite to the lesion side, i.e., the contralesional hemisphere.

Alteration of Cortical Somatosensory Feedback in Post-Stroke Movement Control.

Sensory feedback is of vital importance in motor control, yet is rarely studied in diseases which frequently result in motor deficiency, such as hemiparetic stroke. This study employs the laterality index (LI) of somatosensory evoked potentials (SEPs) to investigate whether sensory feedback is altered in hemiparetic stroke during movements of the paretic arm, with a hemispheric shift from the lesioned hemisphere toward contralesional hemisphere. Through experimental design involving the isometric lifting of the paretic arms during tactile finger stimulation and the analysis of LI in SEPs P50 and N100, we found: 1) increased contralesional sensory activity in stroke participants when they are receiving sensory input in their paretic hand for both P50 and N100 and 2) the contralesional N100 activity is enhanced when stroke participants are performing an isometric arm lifting task.

Implications of Hemispheric Shift of Sensory Feedback during Post-stroke Motor Control on Personalized Stroke Rehabilitation.

Sensory feedback is crucial for motor control as it establishes the internal representation of motion. This study investigates changes in sensory feedback in hemiparetic stroke by analyzing the laterality index (LI) of somatosensory evoked potentials (SEPs) during movements of the paretic arm, focusing on a shift from the lesioned to the contralesional hemisphere. Three chronic stroke participants performed isometric lifts of their paretic arms at two different levels of their maximum voluntary contraction while receiving tactile finger stimulation.