Detecting Damage to the Blood-Brain Barrier of Stroke Patients
Tissue plasminogen activator (tPA), also referred to as the “clot busting” medication, has revolutionized the treatment of acute ischemic stroke. However this medication has a potentially fatal side effect of bleeding in the brain. This complication of tPA has limited the number of patients who are eligible to receive this drug. Even in patients who meet the strict FDA guidelines for use of tPA, approximately 6% of patients will suffer significant bleeding.
Dr. Richard Leigh has developed a novel way to estimate the risk of bleeding stroke patients who are being considered for tPA. This technique uses a type of MRI scan that is routinely acquired in stroke patients for other purposes, and detects damage to the blood-brain barrier which is a maker for bleeding risk. Preliminary results indicate that this new imaging technique will be helpful to clinicians when deciding whether to give, or withhold, tPA. This tool has the potential to increase the number of patients that get treated while decreasing the number of complications.
Understanding How Decreased Blood Flow Affects the Brain Using pH-Weighted MRI
When a blood vessel that supplies the brain is blocked for a prolonged period of time, the consequence is often a stroke. Current MRI techniques are able to measure the blood flow to the brain, however it is difficult to know if such an interruption of blood flow is severe enough to cause injury. Animal studies indicate that brain tissue that is not getting enough blood flow will start to generate lactic acid, which makes it more acidic (lower pH). Thus a method to detect changes in pH of the brain would likely be useful to doctors treating stroke patients.
Researchers at the F. M. Kirby Center designed a new MRI technique to solve this challenge. Lead by Dr. Peter van Zijl, this group developed a method for imaging the pH (acid-base balance) of the brain. In an effort to advance the treatment of acute stroke patients, Dr. Richard Leigh has teamed up with the basic scientists at the F.M. Kirby Center in a translational research project to bring this new pH-weighted imaging into clinical use.
To learn more about the Neuro Vascular Brain Imaging Laboratory, please call 410.614.2381.