DAWN is a groundbreaking study that is changing the way doctors are treating people who have had strokes. Dr. Mark Alberts is the physician-in-chief at the Hartford HealthCare Ayer Neuroscience Institute with details.
Q. What do these protocols mean for stroke patients?
A. This new study (called the DAWN Trial for short) investigated the treatment of acute ischemic stroke (due to blockage of a large blood vessel in the brain) up to 24 hours out from stroke treatment with mechanical thrombectomy. The study found by using advanced imaging and defined clinical criteria, a subset of patients are treatment candidates up to 24 hours out with excellent results. Patients who had a significant amount of brain tissue that was found to be at risk for continuing to stroke who had the clot removed by a catheter based procedure had a significant reduction in disability by about 73%. Before this study, the benefit of treatment beyond 6 hours was not established, but now potentially patients who wake up with stroke symptoms or who we do not know when the stroke symptoms started can be screened and treated.
Q. What type of stroke patient might benefit from these protocols?
A. Patients with ischemic stroke with a large vessel occlusion, meaning a blockage in the brain blood vessel by a blood clot who have significant at risk tissue that can be saved by intervening by removing the clot safely.
Q. When a qualifying stroke patient arrives at the emergency department, what happens? Take us through the process.
A. When a patient comes in, they are assessed for clinical signs of stroke first by the clinician. Typically patients with a blockage of a large blood vessels present with moderate to significant stroke symptoms and severity such as severe weakness on one side or speech and language difficulty etc. A CT scan is performed first to rule out a bleeding type of stroke first. If the patient is within the traditional time window and can be safely treatment with IV clot busters they receive that., if beyond that time window, advanced imaging is done to evaluate for blood vessel blockage and assess the degree of brain tissue damaged already and areas where the damage has not set in yet but is at risk and can be treated. For patients with these criteria, a procedure called mechanical thrombectomy can be done to remove the clot by a catheter based approach.
Learn more about the Hartford HealthCare Stroke Center here.