Effects of Low Intensity Focused Ultrasound Stimulation Combined With Functional Electrical Stimulation on...

Area of Science:

• Neuroscience
• Rehabilitation Medicine

Background:

• Functional electrical stimulation (FES) is used for motor retraining in neurological disorders but has limitations.
• Low-intensity transcranial focused ultrasound stimulation (TUS) offers precise, deep brain stimulation.
• Theta burst TUS (tbTUS) induces neuroplastic changes.

Purpose of the Study:

• To investigate if combining tbTUS with FES enhances corticospinal excitability and motor skill improvement.
• To assess the effects of combined tbTUS and FES on fine motor skills.

Main Methods:

• 15 healthy participants received real or sham tbTUS followed by FES of hand muscles.
• Motor-evoked potentials (MEPs) were recorded at various time points.
• Fine motor skills were assessed using the Nine-Hole Peg Test (NHPT).

Main Results:

• A significant decrease in MEP amplitudes for FDI and OP muscles was observed after real tbTUS+FES.
• MEP amplitudes returned to baseline levels by 80 minutes post-stimulation.
• No significant changes in NHPT scores were found in either condition.

Conclusions:

• Combined tbTUS+FES induces immediate corticospinal inhibition, suggesting homeostatic metaplasticity.
• This neuromodulatory intervention shows potential for further exploration in neurological conditions.
• Further research is needed to optimize tbTUS+FES for therapeutic applications.