Effectiveness of Noninvasive Vagus Stimulation for Upper Extremity in Parkinson's Disease

Investigation of the Effectiveness of Noninvasive Vagus Stimulation on Upper Extremity Functions in Parkinson's Disease

Vagus nerve stimulation in the treatment of PD is a non-pharmacological intervention with the potential to improve gait, cognition, fatigue, and autonomic functions, but more evidence is needed for VSS in the treatment of PD. The potential mechanisms of VSS in the improvement seen in PD are explained by increased cholinergic transmission, decreased neuroinflammation, and enhanced NE release.

In this study, it was aimed to investigate the effects of non-invasive vagus nerve stimulation to be applied to patients with Parkinson's disease on tremor and vagus nerve activity in patients.

The tremor and autonomic activations of the participants will be evaluated at pre and post treatment.

Vagus nerve stimulation in the treatment of PD is a non-pharmacological intervention with the potential to improve gait, cognition, fatigue, and autonomic functions, but more evidence is needed for VSS in the treatment of PD. The potential mechanisms of VSS in the improvement seen in PD are explained by increased cholinergic transmission, decreased neuroinflammation, and enhanced NE release.

5 patients who meet the inclusion criteria will be included in this prospectively planned study. As a vagus stimulation protocol, noninvasive auricular stimulation and stimulation frequency of 10 Hz, pulse width of 300 µs, biphasic application for 20 minutes will be applied to each patient 3 times on different days. Stimulations will be performed 3 times on 3 different days as the right ear, left ear and bilateral ear.

The tremor of the patients participating in the study will be evaluated with the smartphone application. After opening the phone application (G-Sensor), which is used to measure tremor, the patients will be asked to hold the phone in each hand at rest for 30 seconds and the tremor will be recorded. In this application, the maximum amplitude and frequency of the tremor in the 3D plane are calculated automatically.

The effect of vagus nerve stimulation on autonomic nervous system activity is evaluated using heart rate variability with Polar device.

The participants will be evaluated pre and post-treatment.

Inclusion Criteria:

• Being between the ages of 40-65.
• Diagnosed with Parkinson's Disease by a specialist neurologist.
• Hoehn-Yahr stage 2-3.
• Having bilateral resting tremor of the hands.
• Being agreed to participate in the study.

Exclusion Criteria:

• Bilateral or unilateral previous injury to the vagus nerve (eg injury during carotid endarterectomy).
• Severe depression (Beck Depression Scale > 29)
• Current use of any other stimulation device, such as a pacemaker or other neurostimulator; current use of any other investigational device or drug.
• Medical or mental instability (diagnosis of personality disorder, psychosis, or substance abuse) that would prevent the subject from following the protocol timeline.
• Pregnancy or planning to become pregnant or breast-feed during the study period.
• Botox injections or any other upper extremity rehabilitation within 6 months prior to treatment.