However, the clinical studies evaluated the effect of lactate administration on cognitive function in patients with mild traumatic brain injury are still limited. Therefore, we conduct a study to evaluate the effect of exogenous lactate infusion contained in hyperosmolar sodium lactate solution on cognitive function assessed by Mini Mental State Examination (MMSE) score evolution in mild traumatic brain injury compared with patients receiving hyperosmolar sodium chloride 3 % as a control group. MMSE score can be used as a tool to describe cognitive function.