Effect of Non-invasive Vagus Nerve Stimulation on Cerebrovascular Reactivity and Cognition in Chronic Stroke Patients

Overview

This study will be conducted to assess the effect of non-invasive vagus nerve stimulation on cerebrovascular reactivity and cognition in chronic stroke patients

Detailed description

Stroke is a leading cause of disability worldwide, resulting in physical, cognitive, and emotional impairments. These impairments significantly affect individuals, families, and communities. It imposes a substantial social and financial burden on healthcare systems and economies. Deficits in cognitive functions are highly associated with reduced treatment outcomes after stroke. This interferes with social and occupational recovery and limit psychosocial functioning.

Introducing new therapeutic methods such as non-invasive vagus nerve stimulation (VNS) alongside traditional rehabilitation is essential for enhancing cognitive function after stroke. Vagus nerve stimulation can be invasive or non-invasive. Non-invasive method of VNS via transcutaneous stimulation of the peripheral auricular branch of the Vagus nerve (taVNS) is safer, better-tolerated method for delivering VNS with the same effect of invasive VNS.

There are few key human studies that assessed the effects of transcutaneous vagus nerve stimulation (tVNS) on cerebrovascular reactivity (CVR) and cognition in chronic stroke patients. Up to our knowledge, this is the first Egyptian study that will assess the effect of transcutaneous vagus nerve stimulation on cerebrovascular reactivity and cognition in chronic stroke patients. This study will hopefully be of benefit in the physical therapy field. This may guide rehabilitation programs of physical therapy toward better results.

Interventions

• Device Trans-auricular vagus nerve stimulation
  Transcutaneous vagal nerve stimulation will be done through EME Therapic 9200 electrotherapy device (EME Physio, Via degli Abeti 88/161122 Pesaro (PU), Italy). A clip electrode will be applied on cymba conchae of left ear. Stimulation parameters will be set to 30 minutes treatment time, a pulse width of 300 microseconds, pulse frequency 30 HZ and a pulsed mode with a duty cycle of 50% (30 sec on and 30 sec off time).
• Device Sham trans-auricular vagus nerve stimulation
  Patients will receive false trans-auricular vagus nerve stimulation through EME Therapic 9200 electrotherapy device (EME Physio, Via degli Abeti 88/161122 Pesaro (PU), Italy). The ear clip electrode will be attached to the center of the left earlobe of the patient, as it is free from vagus innervation. Stimulation parameters will be set to 30 minutes treatment time, a pulse width of 300 microseconds, pulse frequency 30 HZ and a pulsed mode with a duty cycle of 50% (30 sec on and 30 sec off time)
• Other Conventional physical therapy
  The physical therapy program will include strengthening exercises to the antispastic muscles, stretching exercises to spastic muscles, gait training exercises, proprioceptive neuromuscular facilitation exercises for upper limb and lower limb, and graduated balance exercise.
• Device Computer based cognitive rehabilitation training
  * RehaCom (Dr. G. Schuhfrted Ges.m.b.II., model No. A-2340 device) will be used in this study for assessment and training two cognitive domains: attention/concentration and figural memory. Each patient will be in a comfortable sitting position in front of a screen during the session. The two domains will be assessed at the end of each session. * Attention/concentration domain (AC) includes 24 levels of difficulty. Assessment will start at level one and will be advanced to more challenging levels

Primary outcome measures

• Breathing holding index [Time frame: 4 weeks]

Secondary outcome measures (3)

• Montreal Cognitive Assessment Scale (MOCA): [Time frame: 4 weeks]
• Attention/concentration domain (AC) [Time frame: 4 weeks]
• Figural memory domain [Time frame: 4 weeks]

Eligibility criteria

Inclusion criteria

• Forty chronic ischemic hemiparetic patients, of both sexes, will represent the sample.
• The patient's age will range from 50 to 60 years old.
• Duration of illness will range from six months to twelve months.
• Patients with mild cognitive impairment according to Montreal Cognitive Assessment (MoCA) scale (from 18 to 25).
• Spasticity will be 1 or 1+ according to Modified Aschworth scale.
• Educated patients.

Exclusion criteria

• The patients will be excluded if they have one of the followings:
• Patients with other neurological disease that affect cognition.
• Visual, verbal or hearing impairments that can interfere with communication.
• Depression assessed by Hamilton Depression Scale (Ham-D).
• Patients with poor bone window.
• History of psychiatric disease.
• Hemorrhagic stroke patients.
• Uncontrolled blood pressure or low heart rate.
• Uncontrolled diabetes (>130 mg/dL especially if consistently over 150 to 160 mg/dL)
• Patients with any taVNS contraindications (open heart surgery, pacemaker or other implants, previous surgical intervention on Vagus nerve, Facial or ear pain, and recent ear trauma)
• Stroke patients with severe cognitive impairment.
• Uncooperative patients.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Double blind

Primary purpose

Treatment

Study locations

Egypt · 1 center

• Ahmed Safwat Kamal — Cairo

Identifiers

NCT: NCT07626242 · P.T.REC/012/006121

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗