Divergent Effects of Repetitive Peripheral Stimulation in Subacute and Chronic Stroke: Results From the RESTORES...

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Clinical Trials

Background:

• Repetitive peripheral sensory stimulation (RPSS) above sensory threshold (RPSS_SUPRA) aids motor recovery post-stroke.
• The effects of subsensory RPSS (RPSS_SUB) versus RPSS_SUPRA on motor function and brain chemistry at different stroke stages are not fully understood.

Purpose of the Study:

• To compare the effects of RPSS_SUPRA and RPSS_SUB on motor function and primary motor cortex GABA+ levels in early subacute and chronic stroke phases.
• To investigate the impact of RPSS intensity on motor performance and neurochemical changes.

Main Methods:

• A multicenter, randomized clinical trial involving 51 participants in subacute or chronic stroke phases.
• Participants received a single session of either RPSS_SUPRA or RPSS_SUB of the median nerve, followed by motor training.
• Motor function was assessed using the Jebsen-Taylor test (JTT), and GABA+ levels in the primary motor cortex were measured using proton magnetic resonance spectroscopy.

Main Results:

• Motor performance improved more after training than after RPSS across all groups.
• In the subacute phase, JTT scores declined after RPSS_SUPRA but improved after RPSS_SUB.
• In the chronic phase, both RPSS_SUB and RPSS_SUPRA improved JTT scores. RPSS_SUPRA decreased GABA+ levels in the subacute phase, with no significant changes in other groups.

Conclusions:

• Subsensory and suprasensory RPSS have distinct effects on motor performance and M1 GABA+ levels in stroke survivors.
• The intensity of RPSS influences motor recovery and neurochemical changes differently depending on the stroke phase (subacute vs. chronic).
• These findings highlight the potential for tailored RPSS interventions based on stroke recovery stage.