Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
Dr. Balentine received his undergraduate degree from McDaniel College in Westminster, Maryland. He attended medical school at the Philadelphia College of Osteopathic Medicine graduating in1983. He completed his internship at St. Joseph's Hospital in Philadelphia and his Emergency Medicine residency at Lincoln Medical and Mental Health Center in the Bronx, where he served as chief resident.
Drugs for acute stroke: Currently, only one medicine is approved to treat new strokes. It is the clot-busting medication called tissue plasminogen activator (tPA). This medicine works with the body's own chemicals and helps dissolve the blockage in the blood vessel in the brain that may be causing the stroke. It is the same drug that is often used to treat heart attacks. This is not a miracle drug, but studies of tPA have shown that it can reduce disability from stroke by about 30%. It has potentially serious side effects that include bleeding within the brain. This usually occurs in people who have serious strokes or who were not going to do well regardless of treatment (see the illustration of how effective this drug is). Not all people with stroke can receive the clot-busting drug tPA.
For tPA to work, it must be given within 3 to 4 ½ hours of the onset of symptoms. The earlier the drug is given within those 3 to 4 ½ hours, the better it works. Symptom onset is defined as the time the patient was last known to be okay. If the patient awakens with symptoms, the symptom onset time is set back to the hour he or she went to sleep. This criterion alone may exclude many people from receiving this drug. This is also why it is so important to get to a stroke team for evaluation. Those excluded (>3 to 4 ½ hours) are "… patients over 80 years old, those on oral anticoagulants, those with a baseline NIHSS score >25, those with imaging evidence of ischemic damage to more than one-third of the middle cerebral artery (MCA) territory, and those with a history of both stroke and diabetes mellitus."
The patient must not have any evidence of bleeding on the CT scan of the head. The clot-busting medication is not used for anyone having a hemorrhagic stroke. That is why it is critical to know what kind of stroke the patient is having.
The doctor uses specific guidelines to evaluate whether the patient should receive treatment with this drug and will discuss the risks and benefits of giving it. If given, strict guidelines must be met for the administration of this drug to prevent bad side effects.
Ideally, the tTPA should be given within 60 minutes of the arrival of the patient.
Other treatments for acute stroke are being tested. At some hospitals, clot-busting drugs are given through a small catheter that is threaded up into the neck and into the artery where there is a blockage. This treatment can potentially be used up to 6 hours after onset of stroke symptoms. Recently three large studies compared this technique to the IV method and found no advantages, so this method may undergo revision. Many other new treatments for stroke are being developed. It may be possible to participate in a study of a new stroke drug or another acute treatment.