Lidocaine Infusion Treatment for Subarachnoid Hemorrhage Headaches

The goal of this observational study is to evaluate intravenous lidocaine efficacy and safety in treating headache following non-traumatic subarachnoid hemorrhage. Through this prospective analysis, the investigators hope to: 1. show that intravenous lidocaine infusion causes a clinically significant reduction in pain scores in patients with moderate/severe headache pain following non-traumatic subarachnoid hemorrhage; 2. show that intravenous lidocaine infusion is safe in treating headache following non-traumatic subarachnoid hemorrhage; 3. and report vasospasm prevalence in the cohort. Participants will receive lidocaine infusion as treatment for non-traumatic subarachnoid hemorrhage headache and provide pain scores (on a numeric pain scale) every two hours the patients are awake for a maximum of seven days. Monitoring for vasospasm will occur as part of the patients regular medical care.

Inclusion Criteria: * Patients \> 18 years; * Have a favorable neurological status defined as Hunt and Hess score ≤ 3 (as it accounts for patient awareness); * Can communicate numeric pain scores; * Are diagnosed with non-traumatic subarachnoid hemorrhage Exclusion Criteria: * The patient is diagnosed with traumatic subarachnoid hemorrhage; * If the patient is \< 18 years of age; * If numeric pain scores could not be captured for \> 3 days of hospitalization; * If the patient had a prior aneurysm; * Chronic pain not associated with non-traumatic subarachnoid hemorrhage diagnosis; * A disability before the stroke (\> 2 on modified Rankin Scale score); * A Hunt and Hess score \> 3; * Contraindications to lidocaine (significant cardiac disease, arrhythmia, seizures, previous allergic reaction to lidocaine