In order to study RBD, we needed a lot of brain scans from people who 1) have RBD, and 2) the RBD was caused by a brain injury (such as stroke, cancer, etc.).
Where did we get these scans? We used case studies.
In case studies, an individual who is experiencing a troubling symptom goes to a doctor or other professional to get help. The doctor records the history of the person's symptoms, treats the person, takes brain scans, and follows up to see how treatment went. Sometimes, the doctor thinks that the treatment they did for the patient was so unique, new, difficult, or interesting that other doctors would benefit from learning about the patient and how they were treated. When this happens, the doctor gets permission from the patient to publish a paper about their treatment where they share, without using the patient's name, the history of the person's symptom, the treatment, brain scans (sometimes), and how treatment worked long-term. This helps other doctors to learn and to apply that knowledge if they see another patient in a similar situation.
We searched online for these case studies: specifically ones 1) about RBD, 2) where the RBD was caused by a brain injury (such as stroke, cancer, etc.), and 3) where it included a brain scan. We wrote down detailed notes of how we found each study to show other researchers how we got these results. (For more on this, see the Our Process page of the 10-minute version.)
After finding the case studies, we input the information about what parts of the brain had been injured in each individual into a medical visualization application. Then, we used a supercomputer to analyze the files to see which networks of the brain were affected in most of the individuals. This is how we ultimately got our results.