There are many ways that use of a MSU might prove valuable in stroke patients, but we will focus on acute ischemic stroke (AIS) and treatment with IV tissue plasminogen activator (tPA) within 4.5 hours of symptom onset since that is the most evidence based effective emergency treatment for the most prevalent stroke diagnosis. We hypothesize that the MSU pathway will result in an overall shift towards earlier evaluation and treatment, particularly into the first hour after symptom onset, leading to substantially better outcome. We also hypothesize that as a result of improved clinical outcomes resulting from earlier treatment, the costs of a MSU program will be offset by a reduction in the costs of long term stroke care and increase in quality adjusted life years, thereby supporting more widespread use of this technology. To make MSU deployment more practical, we will confirm that a Vascular Neurologist (VN) on board the MSU can be replaced by a remote VN connected to the MSU by telemedicine (TM) thereby reducing manpower requirements and costs.