header-logo
Brightly colored AI-generated brain on gray gradient background

Nelson Lab Research

The Nelson Laboratory studies patients' feeling and function after traumatic brain injury with goals of improving clinical endpoints for translational studies and clinical trials, better understanding patient heterogeneity, and developing patient-centered improvements in patient care. 
Brightly colored brain

Research Overview

The Nelson Lab focuses on characterizing and improving patient outcomes for traumatic brain injury, or TBI. Using a variety of quantitative—and sometimes qualitative— methods, the Nelson Lab investigates a diverse ranges of TBI-related problems, posing questions such as: 

  • What is the typical course of TBI recovery from the immediate post-injury period onward, such as the areas of subjective symptoms, observable clinical signs, cognitive performance, and day-to-day functioning? 
  • What are the subtypes of TBI that might inform more precision medicine approaches to treatment?
  • How and why do patients differ in their TBI outcomes?
  • How can measures of TBI-related disability be made more sensitive to better reflect treatment effects in clinical trials?
  • What improvements to clinical care would patients with TBI and their families value?
  • How can healthcare systems better adopt evidence-based practices and improve care pathways for persons with TBI?

Active Research Projects

Active research projects in the Nelson Lab include phenotyping traumatic brain injury, improving outcome measurement for clinical trials, understanding individual differences in TBI recovery and outcomes, as well as developing patient-centered systems for care for TBI.

Two variable modeling strategies for traumatic brain injury designating somatic, cognitive and affective variables

Phenotyping Traumatic Brain Injury 

TBI is a heterogeneous injury that affects patients in diverse ways. The Nelson Lab uses latent variable modeling strategies such as factor analysis and latent profile analysis with large, multicenter samples of athletes and community members with TBI to understand heterogeneity in how patients present after TBI, with goals of identifying subtypes of injury that may inform more personalized assessment and treatment approaches. 

 

Representative Publications

Images

Top: Example of a factor model showing how one can conceptualize and estimate latent dimensions of Somatic, Cognitive, and Affective symptoms by modeling the correlations among 9 observed symptom ratings. The dimensions of Somatic, Cognitive, and Affective symptoms are subsumed by a common factor that explains their correlations.

Bottom: A hypothetical latent class model showing how a sample who has rated themselves on Somatic, Cognitive, and Affective symptom dimensions could be stratified into 5 qualitatively distinct subgroups, who differ in their symptom profile. In this example the symptom profiles are Low symptoms, High symptoms, and Somatic, Cognitive, or Affective symptoms only.

Improving Outcome Measurements for Clinical Trials

Alternative outcomes measure for TBI-related disability, graph

Expert's believe the field's long history of unsuccessful clinical trials is, in part, a result of its use of an outcome measure that is not sufficiently sensitive to individual differences in TBI-related disability and recovery. Investigators at the Nelson Lab use Item Response Theory (IRT) and other psychometric tools to understand and improve clinical outcome measures, such as measures of TBI-related symptoms, functional limitations, quality of life, and cognitive performance. Goals of this work are to produce clinical trial endpoints that are better able to detect treatment effects; more accurately reflect patients' experiences of TBI; and improve evidence-based personalized outcome measurement strategies for clinical and translational studies of TBI.

Representative Publications

Image

Figure compares the measurement precision of 3 traumatic brain injury disability outcome measures. The x-axis reflects estimated disability level, as modeled by an item response theory model. The y-axis displays the test information of each of the 3 outcome measures. The measure with the lowest information is the Glasgow Outcome Scale Extended (GOSE), a conventional outcome measure treated as an ordinal 8-level variable. The measure with the next highest information is the GOSE rescored using item response theory. The measure with the highest information is the Functional Status Examination, another measure of injury-related disability.

Understanding Individual Differences in Traumatic Brain Injury Recovery and Outcomes

Factors affecting TBI outcome: pre-injury risk/resilience, injury response, injury characteristics, environmentImproving personalized medicine for TBI will require better understanding why individuals have such different outcomes from what appear to be similar injuries. We investigate how diverse neurobiological, psychosocial, and environmental factors influence acute presentation and outcome from TBI, which will inform ongoing efforts to build systems of care for TBI that address our patients' needs. 

Representative Publications

Image

Figure displays a circular puzzle with 4 quadrants. The top left quadrant conveys pre-injury risk and resilience factors such as genetics, neurophysiology, social determinants, cognitive reserve, psychiatric symptoms, and personality traits. The bottom left quadrant conveys injury characteristics such as cause of injury, TBI characteristics, polytrauma, and complications. The bottom right quadrant conveys environment, exemplified by treatment and rehabilitation, social support, financial resources, secondary gain, and repeated trauma exposure. The top left quadrant conveys injury response, exemplified by symptoms, attributions/expectancies, cognitive sequelae, neurophysiologic response, and epigenetics.

Systems of Care described as Patient Feedback fueling stakeholder engagement, stakeholder engagement fueling clinical improvements and clinical improvements fueling patient feedbackDeveloping Patient-Centered Systems for Care for Traumatic Brain Injury

There is a great need for the development of standardized, coordinated systems of care for persons with TBI around the globe. The Nelson Lab's ongoing projects—led by a multi-stakeholder group of persons with TBI, clinicians, hospital administrators, researchers, and others—is performing mixed-methods research, quality improvement initiatives, and implementation science studies to build better healthcare systems for community members with TBI.  

Image

Figure displays a pie chart with 3 segments—patient feedback, stakeholder engagement, and clinical improvements. Arrows linking the segments convey that they inform each other. 

Recent Publications