NEW YORK, April 23 (Xinhua) -- Even a mild traumatic brain injury (TBI) can highly increase the risk of developing Parkinson's disease, according to a study published in the journal Neurology.

The study, co-authored by Raquel C. Gardner, Amy L. Byers, Deborah E. Barnes, etc. from the University of California, San Francisco, found a strong connection between traumatic brain injuries such as concussions and a heightened risk of Parkinson's disease.

The authors identified all patients with a TBI diagnosis in Veterans Health Administration databases from October 2002 to September 2014 and matched individual with TBI with a non-TBI individual of the same or similar age, to keep the comparison accurate.

The study finds that among 325,870 patients (half with TBI), 1,462 were diagnosed with Parkinson's disease during follow-up. Compared to no TBI, those with TBI had higher incidence of Parkinson's disease.

After adjusting for demographics, medical and psychiatric comorbidities, the study finds that among military veterans, mild TBI is associated with 56% increased risk of Parkinson's disease.

"This study highlights the importance of TBI prevention, long-term follow-up of TBI-exposed veterans, and the need to determine mechanisms and modifiable risk factors for post-TBI Parkinson's disease," the authors wrote.

"Furthermore, because the majority of TBIs sustained by military veterans occur during civilian life either before or after military service, the results of this study may additionally have important implications for civilian and athlete populations," they added.