Combining Non-Invasive Vagus Nerve Stimulation and Robotic Training in Upper Limb-Impaired Chronic Stroke Patients

Combining Non-Invasive Vagus Nerve Stimulation and Robotic Training in Upper Limb-Impaired Chronic Stroke Patients

Previous studies suggested that both robot-assisted rehabilitation and non-invasive vagus nerve stimulation can improve upper limb function in chronic stroke patients. Aim of present study is to explore whether the combination of these two approaches might enhance their positive effects on motor recovery. Safety and efficacy of this combination will be assessed within a proof-of-principle, double-blinded, randomized, sham-controlled trial. Transcutaneous vagus nerve stimulation (tVNS) will be delivered at left ear, in order to improve the response to the following robot-assisted therapy. Patients with both ischemic and hemorrhagic chronic stroke will be randomized to robot-assisted therapy associated with real or sham tVNS, delivered for 10 working days. Change in Fugl-Meyer has been chosen as primary outcome, while changes in several quantitative indicators of motor performance extracted by the robot as secondary outcomes.

Inclusion Criteria:

• first-ever ischemic or hemorrhagic stroke at least 1 year earlier
• hand function impairment
• ability to give informed consent and comprehend instructions

Exclusion Criteria:

• previous surgical intervention on vagus nerve
• low hearth rate (< 60 bpm)
• cognitive impairment or any substantial decrease in alertness, language reception, or attention that might interfere with understanding instructions for motor testing
• apraxia
• excessive pain in any joint of the paretic extremity
• advanced liver, kidney, cardiac or pulmonary disease
• history of significant alcohol or drug abuse
• depression or use of neuropsychotropic drugs such as antidepressants or benzodiazepines
• pregnant women