Sensitivity, Specificity, and Cut-off Point of the Mini-Mental State Examination in Patients With Mild Traumatic Brain Injury

Background and Aim: Most patients suffering from traumatic brain injury (TBI) are those with mild injuries (mTBI). However, due to the absence of symptoms in brain imaging until long after the injury, the manifestations of cognitive impairments remain undiagnosed. Therefore, cognitive screening is considered a key measure in these patients. One of the common screening tools for evaluating cognitive impairments is the mini-mental state examination (MMSE) test. The present study aimed to determine the cut-off point, sensitivity, and specificity of the MMSE test in mTBI patients. Methods and Materials/Patients: In this observational and cross-sectional-analytical study, the statistical population included all patients with mTBI who were injured in the 1st half of 2022. The case group included 79 mTBI patients admitted to the trauma, neurosurgery, and intensive care unit (ICU) departments of Poursina Hospital in Rasht City, Iran, in the 1st half of 2022, who had been referred to the same hospital and Velayat specialized clinic for rehabilitation and re-visit, and the control group included 79 normal healthy individuals. Both groups were cognitively evaluated by the MMSE test on two occasions with an average time interval of 2-3 weeks. Results: The results of the discriminant analysis showed a cut-off point of 27 to 28 as the probable point of cognitive impairment. Also, to identify the cognitive impairment in mTBI patients, this test reported low sensitivity of 0.43-0.58 and a moderate specificity of 0.69-0.80 in two tests. Conclusion: In screening for possible mild cognitive impairment in mTBI patients, the MMSE is relatively useful and should not be used solely to replace a comprehensive neuropsychological evaluation with diagnostic purposes.