Sunday, April 19, 2015
New Ways of Monitoring the Brain Mean Better Outcomes for Those with Severe Brain Injuries
No one ever wants to get the news that someone they love has been diagnosed with a serious brain injury such as a stroke, a trauma or an aneurysm. But if you live anywhere in Westchester Medical Center’s region you should make room for a very precious commodity—hope.
Consider Moira*, an athletic, health-conscious, international business professional in her early 40s. Although Moira had been to her doctor for her severe, recurring headaches, no one suspected that her headaches were actually a sign of something more ominous: Moira’s aneurysm was about to rupture.
“She sat up in bed one night, and told me to call 911,” says her husband, Sean* of that sleeting November night. She was initially taken to a smaller community hospital, where she was diagnosed and stabilized. Then she was rushed to Westchester Medical Center and into the hands of Michael Stiefel, MD, PhD, Chief, Neurovascular Surgery.
Dr. Stiefel is one of the country’s leading researchers in severe brain injuries, and Westchester Medical Center is one of only a handful of medical facilities in the country that has a Trauma ICU and a Neuro ICU experienced in instituting his research.
Dr. Stiefel became intrigued by neural injuries while an undergraduate student at Stony Brook University. While continuing his academic studies of the microscopic events following a brain injury, he wondered what could be done to stop the “cascade” of damage (see sidebar).
“We didn’t have a lot of these ways to look at the brain,” Dr. Stiefel says of the new technology his department uses. “When someone has a severe brain injury, that’s bad. But when we add hypoxia, or lack of oxygen, and blood pressure [issues], how do you monitor that?” Previously, there was no way to measure the cellular metabolism in the brain. All doctors could do was make assumptions by measuring the pressure of the cerebral spinal fluid in the brain, which is pretty general, and by doing tests, such as an MRI or EEG.
Demy Sebastian, RN, discusses monitoring brain metabolism with Dr. Stiefel.
The prognosis for Moira’s type of brain injury is usually poor. “Dr. Stiefel told us she had a 20 to 30 percent chance of survival,” Sean says. But those odds didn’t figure in the technology now available to Dr. Stiefel and his colleagues, Corrado P. Marini, MD, the Director of Trauma and Critical Care at Westchester Medical Center, and Dipak Chandy, MD, Medical Director of the Neuro ICU.
At the heart of this research are four FDA-approved monitors, surgically placed around the injury in the brain, which constantly measure acute signs of brain metabolism in the microenvironment. Since the monitors help them determine what is happening around the site of the injury, in terms of brain perfusion (which is how well the blood is flowing through those tiny capillaries in the tissue next to the injury), oxygen, glucose and metabolism, they can figure out how to stop the secondary damage to surrounding tissue.
Since those factors must remain as consistent as possible in brain tissues in the hours to days after an injury, treatment decisions, such as fine-tuning ventilator settings, administering medications or using other medical interventions must be made quickly if and when any of these critical values start to fluctuate. The name of this game is to optimize the cellular environment around the damaged brain cells, allowing the recovery from the trauma to be as smooth and complete as possible.
And the results?
Studies have been presented on the technology in the Journal of Trauma, Neurocrit Care and the Journal of Neurosurgery, among others. Dr. Stiefel has presented the results of his research several times at national medical conferences. “Fewer than five [hospitals] in the US do all of this for patients,” he says. He’s hoping the technology will spread to save more lives, and improve the quality of those lives saved.
Moira, for example, has intentions of returning to her active life. Three and a half months after her aneurysm, she’s regaining her autonomy, submitting to a steady rehabilitation regimen from home, regaining her overall strength and mental agility. She is planning to return to work when appropriate.
But there’s still work to be done. For instance, if oxygen levels in the brain fall, but the other factors are constant, how do you effectively treat that while minimizing side effects? And if a treatment works for a single patient, how well will that treatment work for other patients? Can we find a way to monitor larger parts of the brain instead of very focused samples? Dr. Stiefel’s research continues, primarily by studying treatment of past patients in retrospective studies. He hopes his research will help develop treatment strategies for future patients.
“We do this in hopes of understanding the injured brain better,” Dr. Stiefel says of his research. “We hope to improve a patient’s outcome. Making a difference is what it’s all about.” •
*To protect patient confidentiality, names have been changed.
The Cascade
It doesn’t take much imagination to understand that injuries to the brain are dangerous. However, many people don’t realize that it’s what happens after the injury that can be critical to survival and recovery.
Remember the last time you banged your shin on the coffee table? It’s doubtful that you injured the bone itself. Instead, you’ve probably damaged “soft tissue” that was between the hard bone and the coffee table. Tiny blood vessels and cells burst upon impact. The damaged vessels start to bleed and leak fluid under the skin, causing swelling. Since this swelling is forced away from the bone and into tissue that has very little space, much like a water being forced into a balloon, your shin hurts. In fact, these “secondary” symptoms, the bruise and swelling that develop after the injury, probably caused you more discomfort than the actual injury itself.
The same thing happens inside the skull. An aneurysm, stroke or trauma sets off a chain of events. After neurons are damaged, bleeding and swelling begins. Unlike the shin, however, the skull encloses the injury. Since swelling cannot expand outward, the blood and fluid is forced inward, into healthy brain tissue that was not originally affected by the injury. This swelling puts pressure on tiny blood vessels flowing into that healthy tissue. That’s when blood flow, and thus the metabolism, in those uninjured cells becomes disrupted. Since the brain cells, more than any other bodily tissue, require an extremely consistent flow of oxygen and glucose, these cells sustain damage and die. That process stimulates even more swelling. In head injuries, this “cascading” effect can cause even more damage than the initial injury.