Safety and Efficacy of Non-invasive Vagus Nerve Stimulation in the Treatment of Headache in Subarachnoid Hemorrhage

This is a single site, randomized, sham-controlled, double-blind study assessing the feasibility, safety, tolerability, and efficacy of non-invasive VNS (nVNS) in the treatment of headache in subarachnoid hemorrhage (SAH). The hypothesis is that two-two minute noninvasive stimulations of the cervical branch of the Vagus nerve, every 5 hours, is efficacious in safely reducing headache intensity and frequency in patients with headache due to SAH, during the patient's intensive care unit (ICU) stay. After screening and obtaining informed consent, eligible patients diagnosed with SAH on head scans, admitted to the Neurosurgical Intensive Care Unit (NSCU) at Northshore University Hospital will be randomized to either the treatment (stimulation of the cervical branch of the Vagus nerve) or sham (inactive stimulation) group. Pain intensity will be evaluated every 4 hours. Non-invasive stimulation will be performed every 5 hours. Device related adverse events, mean headache intensity, and mean and peak morphine equivalence dosage during the study period will be compared between the VNS group and the sham group. The primary objective of this study is to examine the safety and effectiveness of nVNS as a treatment for headache in subarachnoid hemorrhage (SAH). The primary safety endpoint for this study is the incidence of device related serious adverse events. The primary outcome measurements for effectiveness is the difference between the active and sham treatment groups in morphine equivalence dosage Secondary endpoints include descriptive comparisons between the active and sham treatment groups in: * The difference between the active and sham treatment groups in the mean daily headache intensity * The difference between total overall morphine equivalence dosage between the active and sham group per subject during study * Opiate related adverse events (such as urinary retention, constipation, sedation, respiratory depression, nausea, vomiting and pruritis) * The difference in CSF and blood inflammatory markers before and after VNS * Difference in vessel diameter during angiogram for cerebral vasospasm before and after VNS Study period is 14 days starting 24-72 hours post successful treatment of the aneurysm and extubation.