Probing the Mysteries of Brain Injury and Sleep
Date: November 1, 2011
The traumatic brain injury suffered by victims of blasts and car accidents can be challenging to assess and treat. That may in part be because of damage to the pathways along which different areas of the brain communicate—pathways that are largely mysterious because there has never been a good way for researchers to follow them. Now Johns Hopkins researcher John Desmond hopes to cast a light on these pathways with magnetic stimulation. “This will give us a chance to do the first neuroanatomical tracings of the injured human brain,” says Desmond.
Desmond is enlisting the help of transcranial magnetic stimulation (TMS), applied through a coil placed on the scalp. TMS can cause a specific region of the brain to briefly become more active, and that enhanced activity can be clearly imaged via fMRI—along with any other regions that light up in response. In this way, Desmond thinks he’ll be able to chart the paths of brain signals. Comparing the results from a traumatic brain injury patient with those of uninjured subjects could show that one or more of these pathways are damaged in the patient. “That could give us ideas about which areas and functions are most affected by the injury and guide us in treatment,” says Desmond. “And it might give us a good way to monitor progress.”
Insomnia may not seem quite as dramatic a problem, but Johns Hopkins neurologist Rachel Marie Salas thinks another type of brain stimulation might reduce the toll sleeplessness can take on patients’ daytime functioning. Even though insomnia is one of the conditions patients complain of most, says the sleep disorders specialist, “we don’t really have good evaluation and treatment strategies.”
To help clear up some of the questions, Salas is conducting a study in which both insomniacs and good sleepers learn a simple, single-task video game, and then take a two-hour nap while she monitors their brain waves via EEG. The key, she says, is that some of her study participants will also get transcranial direct current stimulation—a mild electric current applied to the scalp with electrodes—to see how it affects either group with the task or sleep. “We want to see if the stimulation can make a difference,” says Salas, “and we want to come up with better ways to evaluate people’s responses to different medications and other therapies.” It’s an idea worth sleeping on.
- Challenge: Find the brain-pathway problems behind traumatic brain injury, and treat insomnia
- Approach: Magnetic stimulation to reveal the pathways, and electrical stimulation to shed light on insomnia
- Progress: Patient studies are planned for brain injury and will be starting soon for insomnia