LIMBIC-CENC: Successfully conducting longitudinal mTBI research during the COVID-19 pandemic.

Background: Conducting mild traumatic brain injury (mTBI) longitudinal studies across multiple sites is a challenging endeavor which has been made more challenging because of COVID-19.

Objective: This article briefly describes several concerns that need to be addressed during the conduct of research to account for COVID-19's impact.

Methods: The recent actions and steps taken by the Long-term Impact of Military-relevant Brain Injury Consortium (LIMBIC)-Chronic Effects of Neurotrauma Consortium (CENC) researchers are reviewed.

Results: COVID-19's effects on the conduct of LIMBIC-CENC for the short-term and long-term were considered to ensure the study continued safely for participants and researchers. COVID-19 may have long-lasting health and especially neurological effects which may confound the quantitative and qualitative measures of this any comparable longitudinal studies.

Conclusion: The recognition, understanding, and preparation of COVID-19's impact on a longitudinal military and veteran mTBI population is crucial to successfully conducting LIMBIC-CENC and similar neurological research studies. Developing a plan based on the best available information while remaining agile as new information about COVID-19 emerge, is essential. Research presented in this special issue underscores the complexity of studying long-term effects of mTBI, in a population exposed to and symptomatic from COVID-19.