This study aims to determine whether transcutaneous vagus nerve stimulation (tVNS) via auricular or cervical branches enhances recovery when combined with task-specific training in subacute stroke patients. We anticipate finding that both stimulation methods may improve upper limb motor function compared to conventional therapy. The research is expected to reveal specific cognitive domains (attention, memory, executive function) that benefit most from each stimulation approach, while also demonstrating meaningful improvements in patients' quality of life measures. These findings may make a significant practical contribution by providing clinicians with evidence-based guidance on suitable tVNS approach for improving functional independence and quality of life for stroke survivors.
Stroke is characterized as a neurological deficit resulting from a sudden focal injury to central nervous system due to vascular issue by blockage and rupture of artery that leads to hypoxic injury and ultimately cell death. Stroke is primarily categories into two types: ischemic stroke that accounts for 85 % of cases and haemorrhagic stroke which make up 15%. Stroke leads to physical, cognitive, speech, perceptual and psychological Impairments. Post stroke impairments of the upper limb and lower limb leads to activity limitations in self-care and mobility and restricted participation in caring family and employment. Multidisciplinary approach is used in stroke rehabilitation to create a rehabilitation program that aim to improve the function and improve the quality of life. Physical medicine and rehabilitation is focused on promoting recovery, improving or restoring functional abilities, anticipating potential long-term complications, and enhancing the quality of life for individuals with physical impairments or disabilities. Now a days there are many contemporary approaches used in rehabilitation like non-invasive brain simulation, robotics, gamification, virtual reality, CIMT, mirror therapy and many others, aimed to enhance the recovery after stroke. Transcutaneous vagus nerve stimulation tVNS was developed two decades ago as a non-invasive, cost effective and easily applicable treatment option as compared to invasive vagus nerve stimulation for the treatment of epilepsy, cognitive impairments and stroke rehabilitation. Cutaneous innervation of vagus nerve is by two branches, one through auricular branch at external acoustic meatus, inner tragus, and the periauricular skin surrounding the cymba conchae and the other through cervical branch at anterior to sternocleidomastoid at the mid of neck. Several devices are used for stimulating the vagus nerve transcutaneously, as NEMOS that stimulates at the concha of outer ear, CE (European Conformity) and a hand held device Gammacore. On the other hand TENS-200 or Digitimer DS7A often require custom-made electrodes, also used in stimulation. In 2018 a systematic review was conducted on the safety of tVNS that results in transcutaneous vagus nerve stimulation (tVNS) is generally well tolerated in humans at the tested doses and is considered safe. In parasympathetic nervous system vagus nerve is a major component that emerges from the medullae oblongata, passes through the jugular foramen to leave the cranial activity and travel downward between the neurovascular bundle situated between internal jugular vein and common carotid artery. It extends to thoracic and abdominal cavities and supply multiple organs and regulate autonomic nervous system. VNS play its role by stimulating the afferent and efferent fibers of the VN that primarily comprises the unmyelinated sensory afferent fibers, accounting for 80-90% of the nerve fiber, with the remaining 10-20% being myelinated efferent fibers. These fibers project upward to the brainstem nucleus and relay circuit, influencing the nucleus tractus solitarius (NTS) and locus coeruleus (LC). NTS projects different brain areas as amygdala, hippocampus, locus coeruleus and prefrontal cortex. The effects of direct VNS on enhancement of memory, motor learning and neuroplasticity also suggest a role for treatment of cognitive disorders, stroke, and other conditions. The cholinergic activity of the efferent branch of the vagus nerve has an immune inflammatory regulatory effect, which is referred to as the cholinergic anti-inflammatory pathway (CAP). Upper limb impairment is a frequent outcome of stroke, greatly affecting a patient's quality of life. Recent research has shown that vagus nerve stimulation (VNS) combined with rehabilitation significantly enhances forelimb strength and movement speed in rat models of ischemic stroke. VNS is thought to amplify the advantages of rehabilitation by fostering neuroplasticity. While the efficacy of taVNS in enhancing motor recovery post-stroke is well-documented, there is a paucity of comparative studies investigating the distinct effects of auricular and cervical tVNS on upper limb function, cognitive outcomes, and quality of life in subacute stroke patients. This gap necessitates further research to determine optimal stimulation modalities and their broader neurorehabilitation benefits
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
54
Group A will receive application of TENS to stimulate the vagus nerve at the ear level, apply the clip electrodes at the targus/cymba concha and the other electrode anywhere in the skin over neck Mode on TENS will be normal, with the width pulse of 250µs. FITT will be as follow Frequency of 25 Hz, Intensity 1mA, Time 30 minutes and the treatment will be of 5 days a week for 8 consecutive weeks * For grip and release: Use a soft ball, putty, or other textured objects. The patient squeezes the object to strengthen their grip and then releases it. * Reaching task: Place objects at varying distances in front of the patient. Encourage them to reach out with the affected arm to grasp the items and then bring them back. * Bilateral arm movement: Encourage simultaneous reaching or moving with both arms (e.g., pushing against a wall or lifting a lightweight object) to promote symmetry and coordination. Improve coordination and function of both arms. * Tabletop activities: Engaging in activities lik
Group B will receive application of TENS to stimulate the vagus nerve at the neck level, apply the pad electrodes at the anterior mid to neck and the other electrode over back of neck Mode on TENS will be normal, with the width pulse of 250µs. FITT will be as follow Frequency of 25 Hz, Intensity 1mA, Time 30 minutes and the treatment will be of 5 days a week for 8 consecutive weeks * For grip and release: Use a soft ball, putty, or other textured objects. The patient squeezes the object to strengthen their grip and then releases it. * Reaching task: Place objects at varying distances in front of the patient. Encourage them to reach out with the affected arm to grasp the items and then bring them back. * Bilateral arm movement: Encourage simultaneous reaching or moving with both arms (e.g., pushing against a wall or lifting a lightweight object) to promote symmetry and coordination. Improve coordination and function of both arms. * Tabletop activities: Engaging in activities like sortin
Shadman Medical Center, Stroke Rehabilitation
Lahore, Punjab Province, Pakistan
RECRUITINGFugl-meyer assessment of upper limb (FMA-UE)
The Fugl-Meyer Assessment-Upper Extremity (FMA-UE) is a commonly utilized tool for measuring motor impairment in stroke rehabilitation. The FMA-UE has demonstrated excellent test-retest and inter- and intra-rater reliability, and evidence for its content validity in acute and subacute populations has been widely reported. The UE section of the FMA consists of 33 items and is scored on a 3-point ordinal scale with 0 meaning cannot perform, 1 meaning can partially perform, and 2 meaning can perform fully. Scores are summed with a maximum potential score of 66 points.
Time frame: baseline, after 4 weeks, after 8 weeks
Montreal cognitive assessment (MoCA)
The Montreal Cognitive Assessment (MoCA) is a one-page, 30-point cognitive screening measurement scale that takes about 10 minutes to administer. There are 12 subtasks in the MoCA test that include memory, visuospatial orientation, executive functioning, phonemic fluency, and two-item abstract thinking task, attention, concentration, and working memory, language, orientation to time and place. A score of 26 is a cutoff score to differentiate between normal and abnormal. These findings suggest that MoCA is a reliable and valid tool for detecting major neurocognitive disorders in older populations.
Time frame: baseline, after 4 weeks, after 8 weeks
Wolf Motor Function Test (WMFT)
The Wolf Motor Function Test (WMFT) is a standardized assessment tool designed to evaluate upper extremity motor function in individuals who have suffered a stroke or other neurological impairments. It measures the ability to perform tasks that require reaching, grasping, and manipulating objects, focusing on both speed and quality of movement. It is a 21 items scale, ranging from simple movements to more complex actions, allowing for a comprehensive evaluation of motor skills. The items are rated on a 6-point scale, it took approximately 30 minutes.
Time frame: baseline, after 4 weeks, after 8 weeks
Stroke-Specific Quality of Life Scale (SS-QOL)
The Stroke-Specific Quality of Life Scale (SS-QOL) is a comprehensive, self-report measure designed specifically to assess health-related quality of life in stroke survivors. The novel 17-item SS-QOL scale (SS-QOL-17) was constructed with the aim of providing a well-balanced measuring tool to depict QOL widely while ensuring the simplicity of administration. It consists of 17- items including mobility, energy, upper extremity function, work/productivity, mood, self-care, social roles, family roles, vision, language, thinking, and personality. Each item is rated on a 5-point Likert scale, with higher scores indicating better function. The total score ranges from 49 to 245, with domain scores calculated as the mean of item scores within each domain.
Time frame: baseline, after 4 weeks, after 8 weeks
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