Neurology highlights work from Drs. Leng, Byers, Barnes, and Yaffe on TBI and risk of sleep disorders.

MINNEAPOLIS - People who have concussions may be at increased risk of developing sleep disorders years later, according to a study published in the March 3, 2021, online issue of Neurology®, the medical journal of the American Academy of Neurology. “We found that people with TBI had an increased risk of insomnia, sleep apnea, sleep-related movement disorders and excessive daytime sleepiness—every sleep disorder we looked at,” said study author Yue Leng, M.D., Ph.D., of the University of California, San Francisco. “Since sleep disorders affect people’s quality of life and their rehabilitation process, it will be important to develop strategies to identify these disorders early as well as prevent them from occurring after traumatic brain injuries to improve people’s overall health and quality of life.” The study looked at all people diagnosed with a traumatic brain injury (TBI) within the Veterans Health Administration system. The 98,709 veterans with TBI were matched by age with the same number of veterans with no history of traumatic brain injury. The injuries ranged from mild traumatic brain injuries, or concussions, to severe TBIs. None of the people had sleep disorders at the start of the study. The people were followed for a total of 14 years. During that time, 23,127 people with TBI developed sleep disorders, or 23%, compared to 15,583 people without TBI, or 16%. After researchers adjusted for other factors that could affect risk of sleep disorders, such as diabetes, tobacco use or substance use disorder, they found that people with TBI were 40% more likely to develop a sleep disorder than people without TBI. Eleven percent of the veterans with TBI developed sleep apnea, compared to 8% of those without TBI. For insomnia, 12% of those with TBI started experiencing it, compared to 7% of those without TBI. People who had post-traumatic stress disorder were not more or less likely to develop sleep disorders than those who did not have post-traumatic stress disorder. The researchers found that the association between TBI and sleep disorders was stronger for people who had mild traumatic brain injuries than for those who had moderate or severe TBIs. “More research is needed to determine the underlying mechanisms for a link between different severity of TBI and development of sleep disorders,” Leng said. “The stronger association for people with mild TBI could be due to the different brain injury mechanism for those injuries, which often involve repetitive concussive injuries or acceleration or deceleration injuries causing more diffuse injury and inflammation, compared to moderate or severe TBIs, which are often due to a direct blow to the head with more focused but severe damage.” Limitations of the study were that TBI and sleep disorders were determined by medical diagnoses codes, which may be less sensitive than a clinical assessment, and sleep disorders may have been underdiagnosed. The study was supported by the U.S. Army Medical Research and Material Command and U.S. Department of Veterans Affairs. Learn more about brain health at, home of the American Academy of Neurology’s free patient and caregiver magazine focused on the intersection of neurologic disease and brain health. Follow Brain & Life® on Facebook, Twitter and Instagram. When posting to social media channels about this research, we encourage you to use the hashtags #Neurology and #AANscience.

The American Academy of Neurology is the world's largest association of neurologists and neuroscience professionals, with 36,000 members. The AAN is dedicated to promoting the highest quality patient-centered neurologic care. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Alzheimer's disease, stroke, migraine, multiple sclerosis, concussion, Parkinson's disease and epilepsy.

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