Effects of Trans-Auricular Vagal Stimulation on Neuromotor Recovery in Subacute Stroke During Technological and Traditional Training

Istituti Clinici Scientifici Maugeri SpA48 enrolled

Overview

This randomized pilot clinical study aims to investigate the effects of trans-auricular vagus nerve stimulation (tVNS) on neuromotor recovery in patients in the subacute phase after stroke. Participants admitted for intensive rehabilitation at ICS Maugeri Centers (Montescano, Pavia, Nervi) will be randomized into four groups receiving either traditional or technological rehabilitation (Khymeia device), combined with active or sham tVNS. The Parasym® device (CE 0197) delivers non-invasive stimulation of the auricular branch of the vagus nerve at the left ear for 60 minutes daily. The primary outcome is the improvement in upper limb motor function, assessed by the Fugl-Meyer scale. Secondary outcomes include other clinical, cognitive, and psychological measures, as well as neurophysiological and cardiovascular autonomic parameters. The study hypothesizes that coupling tVNS with rehabilitation enhances cortical plasticity and accelerates motor recovery. Adverse effects are expected to be minimal, with previous studies reporting only mild transient skin irritation. The results may provide new insights into the neurophysiological mechanisms of recovery and support the integration of non-invasive neuromodulation in post-stroke rehabilitation.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Enrollment

Conditions

Stroke

Interventions

Active trans-auricular vagus nerve stimulation (tVNS)DEVICE

Active tVNS with the Parasym® device (CE 0197). Electrode placed on the left tragus, 25 Hz, 250 μs, intensity to tolerance, 60 min/day, 5 days/week for 4 weeks.

Sham tVNSDEVICE

Sham tVNS using the Parasym® device with electrodes on the left earlobe (non-vagal area). Same schedule as active tVNS (60 min/day, 5 days/week for 4 weeks).

Khymeia robotic upper limb rehabilitationDEVICE

Robotic-assisted rehabilitation for the upper limbs using the Khymeia system.

Traditional RehabilitationBEHAVIORAL

Standard traditional physical therapy and rehabilitation protocols for upper limb recovery.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Patients with hemiplegia following ischemic or hemorrhagic stroke occurred within the previous 6 months, clinically stable * Age ≥ 18 years * Single cortical or subcortical lesion documented on neuroimaging, corresponding to the motor deficit * Cognitively able to understand and follow therapeutic instructions * Upper limb weakness confirmed by a Motricity Index score below maximum * Spasticity, if present, compatible with limb function (Modified Ashworth Scale ≤ 2) * Written informed consent provided Exclusion Criteria: * Multiple brain lesions on neuroimaging * Severe spasticity (Modified Ashworth Scale 3-4) * Aphasia preventing comprehension of verbal instructions * Cognitive decline or behavioral disorders interfering with collaboration during training * Orthopedic conditions or surgical outcomes preventing the execution of the rehabilitation training

Outcomes

Primary Outcomes

Upper limb motor recovery assessed by Fugl-Meyer Assessment (FMA-UE)

The FMA-UE is a scale used to measure sensorimotor impairment. Scores range from 0 to 66, where higher scores indicate better motor function.

Time frame: Baseline and 4 weeks after treatment

Secondary Outcomes

Functional Independence Measure (FIM)

The FIM assesses the physical and cognitive disability of a patient. Total scores range from 18 to 126, where higher scores indicate greater independence in activities of daily living.

Time frame: Baseline and 4 weeks.

Barthel Index

The Barthel Index measures the extent to which a person can function independently and has mobility in activities of daily living (ADL). The total score ranges from 0 to 100, where higher scores indicate better performance and greater independence.