TBI Research Round-Up: Link to Parkinson and Novel Treatment Approach

With continued pressure from the public and announcements from sport celebrities like Brett Favre voicing concern about concussions and traumatic brain injury (TBI), researchers and clinicians alike continue to search for improved prevention, detection, and treatment options.

The negative effects of repeated head trauma are clear, and new evidence is emerging that even a single event can have deleterious effects. In a study published in the April issue of Neurology, Kristine Yaffe, MD, professor of psychiatry, neurology and epidemiology and the Roy and Marie Scola Endowed Chair at the University of California, San Francisco, and colleagues explored the link between TBI and the increased risk of Parkinson disease.¹ The study, which followed 325,870 veterans selected from three medical databases for an average of 4.6 years, found a 56% increased risk of developing Parkinson in people who had mild traumatic brain injury. The risk increased to 83% in patients who had severe traumatic brain injury. Furthermore, Yaffe et al. noted patients with any form of TBI were diagnosed two years earlier, on average, than their counterparts without TBI.

“This study highlights the importance of concussion prevention, long-term follow-up of those with concussion, and the need for future studies to investigate if there are other risk factors for Parkinson’s disease that can be modified after someone has a concussion,” co-author Raquel C. Gardner, MD, assistant professor of neurology at the University of California, San Francisco, said in a press statement. “While our study looked at veterans, we believe the results may have important implications for athletes and the general public as well.”

To help clinicians better understand TBI and its consequences, researchers from Portland State University published results of their study using “causal-loop diagramming to visualize relationships between factors influencing the pathophysiology and recovery trajectories of concussive injury, including persistence of symptoms and deficits.”² Their interdisciplinary approach looked at TBI’s effects on a biological level (including cellular and neural networks) as well as somatic, cognitive, and affective symptoms. Their loop and feedback analysis allows for a better understanding of how systems and interventions behave in patients with TBI and may lead to the development of improved interdisciplinary treatment approaches.

“Our causal-loop diagram shows how specific variables and processes interact to influence concussion recovery. By analyzing patterns in the feedback dynamics, we can better understand how recovery might be facilitated or impeded,” lead author Erin S. Kenzie, doctoral student and member of Portland State University’s Dynamic Model Initiative, explained in a statement to the press.

Attendees of the American Academy of Neurology 2018 Annual Meeting will have the opportunity to further explore issues in evaluating concussion and TBI. Among several discussions, David W. Dodick, MD, professor of neurology at Mayo Clinic College of Medicine and a consultant in neurology at the Mayo Clinic in Scottsdale, Arizona, will be sharing research updates on the early and late sequelae of concussion as well as the management of post-concussion symptoms on Tuesday, April 24^th. Check back regularly with Neurology Times to learn more about the meeting. 

References:

• Gardner RC, Byers AL, Barnes DE, et al. Mild TBI and risk of Parkinson disease: A Chronic Effects of Neurotrauma Consortium Study. Neurology. Online Access. April 18, 2018.
• Kenzie ES, Parks EL, Bigler ED et al. The Dynamics of concussion: Mapping pathophysiology, persistence, and recovery with causal-loop diagramming. Front Neurol. April 17, 2018.