This study will be conducted to assess the effect of non-invasive vagus nerve stimulation on cerebrovascular reactivity and cognition in chronic stroke patients
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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
40
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).
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).
Ahmed Safwat Kamal
Cairo, Egypt
Breathing holding index
Transcranial doppler ultrasonography technique will be used to assess cerebrovascular reactivity by measuring the percentage increase in cerebral blood flow velocity during apnea, divided by the duration of breath hold in seconds. Breath holding index will be calculated according to the following equation: BHI= ((Mean Flow Velocity (MFV) post- Mean Flow Velocity (MFV)rest/ Mean Flow Velocity (MFV)rest) × (100/Duration in second)) normal range:1.03-1.65.
Time frame: 4 weeks
Montreal Cognitive Assessment Scale (MOCA):
It will be used to assess cognition before and after treatment period for all patients. Each patient will be asked to write and draw using the non-affected hand. The test consists of a single page, with reading items presented in a clear and appropriately sized font. The assessment will include short-term memory, executive functions, visuospatial abilities, language, attention, concentration, working memory, and temporal and spatial orientation. Total score of MoCA is from 0 to 30. From 26-30 is normal cognition, from 18-25 is mild cognitive impairment (MCI), from 10-17 is moderate cognitive impairment, and less than ten is Severe cognitive impairment.
Time frame: 4 weeks
Attention/concentration domain (AC)
RehaCom (Dr. G. Schuhfrted Ges.m.b.II., model No. A-2340 device) will be used in this study to assess and rehabilitate the cognitive function in stroke patients. It is a valid and reliable instrument for assessing and improving cognitive functions in stroke patients. Attention/concentration domain (AC) includes 24 levels of difficulty. Assessment will start at level one and will be advanced to more challenging levels. normal range :10-12 level; indicative cognitive impairment: below 10 level
Time frame: 4 weeks
Figural memory domain
RehaCom (Dr. G. Schuhfrted Ges.m.b.II., model No. A-2340 device) will be used in this study to assess and rehabilitate the cognitive function in stroke patients. It is a valid and reliable instrument for assessing and improving cognitive functions in stroke patients. Figural memory domain includes 9 levels of difficulty. Assessment will start at level one and will be advanced to more challenging levels. normal range :7-8 level; indicative cognitive impairment: below 7 level
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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.
* 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. * Figural memory domain includes nine levels of difficulty. Assessment will start at level one and will be advanced to more challenging levels. Each cognitive training session will last 30 minutes, with 15 minutes dedicated to each targeted domain.
Time frame: 4 weeks