If physical Zheng Wang, a therapist in Shanghai, worked with people recovering from strokes after their brains were damaged by lack of oxygen. They usually followed a predictable pattern of recovery, made great progress during the first few visits, and then hit a wall. Patients asked when they would finally feel normal, and Wang told them they would get better with time. “But actually,” he recalls, “I knew from the bottom of my heart that they weren’t going to improve much, no matter how hard we tried.”
Meanwhile, halfway around the world, Marc Dalecki, then an associate professor in the School of Kinesiology at Louisiana State University (LSU), couldn’t stop thinking about oxygen. Dalecki spent much of his early career studying scuba diving and remembers divers using nasal cannulas of O2 to help with everything from hypoxia to headaches. He always wondered if this simple treatment could help neurological patients in rehabilitation. “I promised myself I would study it if I got my own research lab,” he says.
For its relatively small size, the brain expends a ridiculous amount of energy: 20 to 30 percent of the body’s energy at rest. To fuel all its neurons, the brain depends on oxygen. When someone has a stroke or head injury, the flow of oxygenated blood to the brain becomes disrupted. Without oxygen, brain tissue is damaged, leading to numerous problems with memory, speech, strength, and motor control.
Rehabilitation from brain trauma usually involves working with a physical therapist to relearn motor skills, building the strength and coordination needed for daily activities, such as making coffee, writing, and brushing your teeth. Many physical therapists are already using high-tech devices to help patients recover faster, from robots that move damaged limbs to virtual reality games that simulate aspects of everyday life that can’t be easily replicated in a hospital setting. But Wang and Dalecki both wondered if oxygen could be the simple, cheap, and accessible addition to neurological rehabilitation they’ve been looking for. If they could give patients a little extra oxygen during early motor rehabilitation sessions, they thought, they’d be able to relearn old skills more quickly.
The two joined forces in Dalecki’s lab at LSU, where Wang, frustrated as a clinician, decided to pursue a PhD in kinesiology. In a study published last week in Frontiers in neuroscience, their team showed that sniffing pure oxygen while learning a challenging motor task helped healthy young people learn faster and perform better. They think this relatively inexpensive, low-risk idea could be used to accelerate stroke recovery.
For their study, they recruited 40 healthy young adults to each sit at a desk while wearing a nasal cannula. Their instructions were simple: hold a stylus in the center of a tablet screen and drag it as quickly and efficiently as possible to a target that appears elsewhere. But after a few tries, the relationship between the stylus and the screen shifted, creating a 60-degree difference between the line a participant thought they drew and the line actually appeared on the screen. As the volunteers adjusted their line drawing to these new, more challenging conditions, air began to flow through the cannula. Half of the participants received pure oxygen, while the other half received medical air (essentially an ultra-clean version of regular air). It was a quick blast just during these few minutes of initial learning. Then the airflow stopped and the screen returned to normal.