Role of the Microbiome in the Persistence of Complex Regional Pain Syndrome

A car accident during medical school profoundly affected Dr. Lara Wiley Crock, MD, PhD, MSCI’s life. Fortunate to recover, she became more aware of the many patients in the clinical settings who did not fully recover and set out to understand why. This propelled Dr. Crock down a path to better understand pain and how research may be able to influence patient outcomes related to it. With the help of a 2019 IARS Mentored Research Award, she began to unravel those unknowns with a study, “Role of the Microbiome in the Persistence of Complex Regional Pain Syndrome,” focused on identifying gut microbiota differences in acute and chronic pain due to specific pain condition and determining if this information could predict who would develop chronic pain after an acute injury by their microbiota differences. In examining patients with chronic complex regional pain syndrome (CRPS) and household members without CRPS as a control, they found something that no one had observed before. About 50% of participants with CRPS lived with someone with chronic pain (as opposed to a 20% prevalence in the general population). Although this is just an observation in this adult population, this finding may well be an independent risk factor for the development of chronic pain. Dr. Crock and her research collaborators continue to pursue answers to this question, making progress towards early identification of patients at high risk for the development of chronic pain and preventing its development. Below, she shares her research journey, how the IMRA helped her progress in her career as a researcher and her hopes for the future of the study of pain.

1. What is your current position? How long have you been in this position? What was your role when you were first funded by IARS?

I am an assistant professor since 2020, was a resident/fellow (combined advanced research track) when I was funded.

2. What drew you to academic anesthesiology and to your particular area of research? Has your research subject area evolved since the award?

I have been interested in pain research since graduate school. I was in a car accident during medical school, which profoundly affected my life. I was lucky to recover, but most patients I see in the clinical setting do not. I wanted to research pain to figure out why different patients have different trajectories and if we can influence them.

3. What was the goal of your initial research project? Was it met?

The goals of my initial project were to identify gut microbiota differences in acute and chronic pain due to specific pain condition and determine if we could predict who would develop chronic pain after an acute injury by their microbiota differences. To accomplish this, we first examined taxonomic differences in gut microbiota between patients suffering from acute and chronic complex regional pain syndrome (CRPS), compared to each other as well as household controls (people who live with them without CRPS, but may have chronic pain) and non-cohabitating healthy controls. Second, we planned on longitudinal enrollment of patients with acute complex regional pain to determine how their gut microbiota changed as they recovered from this pain condition or developed chronic pain. The COVID-19 pandemic made longitudinal enrollment a challenge, so we adjusted our second aim to include a mouse model of complex regional pain syndrome.

4. How did your findings impact patient care?

Not yet.

5. How did your research impact the field of anesthesiology?

In examining patients with CRPS and household members without CRPS as a control, we found something that no one had observed before. About 50% of participants with CRPS lived with someone with chronic pain (as opposed to a 20% prevalence in the general population). In the pediatric literature, it is clear that children whose parents have chronic pain are more likely to develop chronic pain themselves. Although this is just an observation in this adult population, this may well be an independent risk factor for the development of chronic pain. Other studies we are doing are not including questions about household members. In addition, we found in both mice and people, there is a significant decrease in the richness and diversity of the gut microbiota in those with CRPS when compared to healthy controls.

6. How did the award affect your research/professional trajectory?

This award gave me the confidence to apply for additional grants, and obtain preliminary data to start my research career. I have not yet obtained external funding, but am actively involved in research.

7. How do you feel about having received the IARS Mentored Research Award?

I feel incredibly lucky and grateful to have received this award. I was able to develop a new set of skills in the application of clinical and translational research.

8. What is something that someone would be surprised to learn about you?

I met my husband at a skate park.

9. What is your vision for the future of anesthesia research?

My hope is that we can move towards early identification of patients at high risk for the development of chronic pain and prevent its development.