This is a randomized open-label, with blinded outcome pilot study to evaluate the effect on inflammatory laboratory values and explore clinical outcomes in patients who present with ischemic strokes due to large vessel occlusions and are treated with either current accepted management, or accepted management in addition to transcutaneous auricular vagal nerve stimulation.
Stroke is a leading cause of death and disability worldwide. Approximately 80% of strokes are caused by cerebral ischemia. Although stroke is the third leading cause of death after heart disease and cancer, it leads to permanent disabilities in 80% of survivors. Large vessel occlusions (LVOs) account for up to 38% of acute ischemic strokes (AIS). LVOs represent a clinically significant subpopulation of cerebral ischemia due to their disproportionate morbidity and mortality without treatment. Up to 64% of patients without treatment of their LVO are dead or dependent at 3-6 months. Even after successful treatment (recanalization), infarcts can continue to increase in size, a process referred to as ischemia-reperfusion injury, for which even patients who are successfully treated in the acute setting can have poor outcomes. Highlighting the need for adjunct therapies to minimize ischemia progression for both post recanalized and unrecanalized patients. Neuroinflammation has long been recognized as an important element of AIS pathology. In the acute phase of AIS, non-specific inflammatory markers such as C reactive protein, and classical pro-inflammatory cytokines are elevated and have been associated with aggravating brain injury. An interesting avenue of research has now aimed to better understand, and eventually to target these inflammatory pathways to improve outcomes after AIS, with anti-inflammatory interventions trialed in humans. Although ongoing trials are occurring in AIS, the immunomodulation agents can be costly and have marked side effects, for which finding adjunct treatments that are easy to administer and with minimal side effects is of the utmost importance. Vagal nerve stimulation (VNS) has previously been established to have anti-inflammatory effects, and has been successfully demonstrated in other models of inflammatory conditions. Given these promising results in animal studies of AIS, and the established safety of the noninvasive transcutaneous auricular VNS (taVNS), the authors propose prospectively studying this non-morbid and safe intervention in our AIS patients due to LVO population at Barnes Jewish Hospital. Our central hypothesis is that implementing transcutaneous auricular vagal nerve stimulation (taVNS) in the acute period following an ischemic stroke due to a large vessel occlusion will attenuate the expected inflammatory response to the stroke and will curtail morbidity associated with inflammatory-mediated clinical endpoints (i.e., infarct progression). The investigators aim to determine if inflammatory markers in the blood are impacted in patients treated with noninvasive VNS, and as a secondary outcome track patient outcomes to better understand the impact on morbidity and mortality. Patients enrolled in the trial will be randomized to treatment with electrical stimulation to the auricular branch of the vagus nerve (intervention) or stimulation to the great auricular nerve (cervical nerve branch)(Sham) via an auricular, transcutaneous vagus nerve stimulator. All patients will be fitted with the device, the investigators will attach adhesive contacts to the left ear. Stimulation sessions will occur for 20 minutes twice daily during the inpatient period. Patients will have electricity applied to the different nerves depending on the randomization, they will be treated with stimulation with the following parameters: frequency 20 Hz, pulse width 250 µm, and a fixed intensity of 0.5 milliampere. The amplitude of stimulation may be reduced if a patient complains of discomfort at the site of stimulation. The site of stimulation will be inspected daily before and after treatment to ensure there is no redness or irritation at the site. The investigators will obtain laboratory samples on admission, day 0, and every 1.5 days till day 5 or discharge (whichever occurs first) to assess the patients inflammatory markers.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
40
Stimulus of the auricular branch of the vagal nerve with the transcutaneous auricular vagal nerve stimulation.
Patients assigned to the controls arm will have no electricity applied to the Auricular Branch of the Vagus Nerve. Stimulus will be provided to the lobule of the ear, which is not innervated by the Auricular Branch of the Vagus Nerve.
Washington University in St. Louis School of Medicine
St Louis, Missouri, United States
Interleukin - 1b - Changes and Differences in the Levels
The primary endpoint was change in inflammatory biomarkers from baseline to day 5, with samples obtained every 1.5 days. Interleukin-1β was the main analyte. Repeated measures were analyzed longitudinally using mixed-effects models (FDA guidance), specifying subject as a random effect to account for multiple observations. This approach accommodated irregular timing, missing data, and time-varying covariates. Models included treatment, time since last known normal, and their interaction to test group differences in biomarker trajectories. Time was modeled quadratically for cytokine and WBC outcomes to capture U-shaped temporal patterns. Interaction p-values assessed trajectory differences between taVNS and sham arms.
Time frame: 5 days
Interleukin - 6 - Changes and Differences in the Levels
The primary endpoint was change in inflammatory biomarkers from baseline to day 5, with samples obtained every 1.5 days. Interleukin-6 was the main analyte. Repeated measures were analyzed longitudinally using mixed-effects models (FDA guidance), specifying subject as a random effect to account for multiple observations. This approach accommodated irregular timing, missing data, and time-varying covariates. Models included treatment, time since last known normal, and their interaction to test group differences in biomarker trajectories. Time was modeled quadratically for cytokine and WBC outcomes to capture U-shaped temporal patterns. Interaction p-values assessed trajectory differences between taVNS and sham arms.
Time frame: 5 days
Tumor Necrosis Factor Alpha - Changes and Differences in the Levels
The primary endpoint was change in inflammatory biomarkers from baseline to day 5, with samples obtained every 1.5 days. Tumor necrosis factor was the main analyte. Repeated measures were analyzed longitudinally using mixed-effects models (FDA guidance), specifying subject as a random effect to account for multiple observations. This approach accommodated irregular timing, missing data, and time-varying covariates. Models included treatment, time since last known normal, and their interaction to test group differences in biomarker trajectories. Time was modeled quadratically for cytokine and WBC outcomes to capture U-shaped temporal patterns. Interaction p-values assessed trajectory differences between taVNS and sham arms.
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Time frame: 5 days
White Blood Cell Total Count - Changes and Differences in the Levels
The primary endpoint was change in inflammatory biomarkers from baseline to day 5, with samples obtained every 1.5 days. WBC count was the main analyte. Repeated measures were analyzed longitudinally using mixed-effects models (FDA guidance), specifying subject as a random effect to account for multiple observations. This approach accommodated irregular timing, missing data, and time-varying covariates. Models included treatment, time since last known normal, and their interaction to test group differences in biomarker trajectories. Time was modeled quadratically for cytokine and WBC outcomes to capture U-shaped temporal patterns. Interaction p-values assessed trajectory differences between taVNS and sham arms.
Time frame: 5 days
Neutrophil to Lymphocyte Ratio - Changes and Differences in the Levels
The primary endpoint was change in inflammatory biomarkers from baseline to day 5, with samples obtained every 1.5 days. neutrophil to lymphocyte ratio based on blood samples was the main result of interestse. Repeated measures were planned to be analyzed longitudinally using mixed-effects models (FDA guidance), specifying subject as a random effect to account for multiple observations. This approach accommodated irregular timing, missing data, and time-varying covariates. Models included treatment, time since last known normal, and their interaction to test group differences in biomarker trajectories.
Time frame: 5 days
Change in NIH Stroke Scale (NIHSS)
The secondary endpoint was change in NIHSS from baseline to discharge (\~ day 5) and 30 days. Change in the NIHSS stroke scale number (0-42 and a measure of severity) was the outcome of interest. Repeated measures were analyzed longitudinally using mixed-effects models (FDA guidance), specifying subject as a random effect to account for multiple observations. This approach accommodated irregular timing, missing data, and time-varying covariates. Models included treatment, time since last known normal, and their interaction to test group differences in biomarker trajectories. Time was modeled quadratically for cytokine and WBC outcomes to capture U-shaped temporal patterns. Interaction p-values assessed trajectory differences between taVNS and sham arms and linearly for in-hospital NIHSS scores based on panel data plots. Interaction terms were utilized to delineate differences amongst trajectories of the outcome of interest.
Time frame: 30 days
Modified Ranking Scale (mRS)
This is a clinical secondary exploratory endpoints. The Modified Ranking Scale (mRS) is a clinical tool used to assess functional status after suffering a stroke. It ranges from 0 up to 6. It was assessed at day 90. The investigators will assess differences in mRS dependent of the intervention arm. 0 = no symptoms at all 1. = No significant disability despite symptoms; able to carry out all usual duties and activities 2. = Slight disability; unable to carry out all previous activities, but able to look after own affairs without assistance. 3. = Moderate disability; requiring some help, but able to walk without assistance. 4. = Moderately severe disability; unable to walk without assistance and unable to attend to own bodily needs without assistance 5. = Severe disability; bedridden, incontinent and requiring constant nursing care and attention. 6. = Dead
Time frame: 90 days
Number of Participants With Treatment-related Adverse Events as Assessed by CTCAE v4.0 - Hypotension (C143352)
The investigator will monitor the patient's blood pressure (millimeters of mercury - mmHg) before, during, and after the transauricular vagal nerve stimulation or sham. If hypotension occurs (systolic blood pressure less than 80 mmHg or mean arterial pressure \<60 mmHg) , the investigator will document it and assigned the appropriate grade from 1-5 based on the CTCAE.
Time frame: 5 days
Number of Participants With Treatment-related Adverse Events as Assessed by CTCAE v4.0 - Sinus Bradycardia (C54940)
The investigator will monitor the patient's heart rate (beat per minute) before, during, and after the transauricular vagal nerve stimulation or sham. If Sinus Bradycardia (C54940) occurs (heart rate less than 60 beats per minute), the investigator will document it and assigned the appropriate grade from 1-5 based on the CTCAE.
Time frame: 5 days