How a literature search sheds light on rare health condition

Sarah Witney

5/7/2025

Summary: I studied how REM Sleep Behavior disorder is impacted by a dynamic team of different areas in the brain with the goal of helping clinicians provide their patients with more accurate predictions of what to expect after a brain injury. 

A couple of years ago, I worked on a project that combined medical research, data analysis, and brain imaging to explore a sleep disorder called REM Sleep Behavior Disorder (RBD). While the topic came from the medical world, the skills I used—searching through messy data, spotting patterns, and building clear visual summaries—apply to many fields.

Here’s a look at the project and what it revealed.

The Problem

REM sleep is the part of the sleep cycle when we dream. Normally, our brain temporarily “turns off” our muscles so we don’t move around while we dream.

But for people with REM Sleep Behavior Disorder, this system doesn’t work properly. Instead, their bodies act out their dreams—they might kick, punch, or even leap out of bed. That makes it not only confusing, but potentially dangerous.

This raised an important question: What parts of the brain are responsible for this disorder, and why do injuries in very different brain areas sometimes cause the same condition?

The Process

To answer this, I used a method called lesion network mapping—in simpler terms, it means analyzing how an injury to one part of the brain can affect other connected areas.

Here’s how I approached it:

• I searched through published medical case studies to find examples where someone developed REM Sleep Behavior Disorder due to a brain injury or disease—and where the brain scans were available.

• I selected the clearest, most informative scans and used a tool called Mango to map the exact areas of the brain that were damaged.

• From there, I used data on brain activity to see which other areas were closely connected to the damaged parts—even if they weren’t injured themselves.

• Finally, I created heat maps that showed which brain areas were “in sync” with the injury (lighting up in green) and which showed opposite activation patterns (shown in red).

Why This Matters

Before this research, the leading theory was that injuries to the brainstem—the lowest part of the brain near the neck—were the main cause of RBD. While many injuries we reviewed did involve various areas in the brainstem, others were located in different regions of the brain as well but still led to RBD.

Our findings help explain why: these non-obvious injuries were likely disrupting larger brain networks responsible for REM sleep motor control. In other words, REM Sleep Behavior Disorder may not result from damage to a single “off-switch,” but rather to a distributed network that helps keep us safely still while dreaming.

Ultimately, we hope this work will help healthcare providers develop safer, more informed treatment plans. The results have been shared with a research group building a comprehensive database of brain injuries and their outcomes, with the goal of helping clinicians give people with brain injuries more accurate prognoses—so patients and families can better understand what to expect and make more confident decisions about care. 

It’s my hope that this research contributes to a future where individuals with REM Sleep Behavior Disorder—especially those recovering from brain injury—can get the care they need to stay in bed and stay safe. 

For more information on the study, further reading, and a colorblind-friendly version of the heat maps, see: https://sites.google.com/view/lnm-explained/start-here

You can also contact Sarah Witney with questions at sarahwitney23@gmail.com

You can find out more about the research team assembling the database at https://brain.byu.edu/research