Brain functional connectivity and cognition in mild traumatic brain injury.

ABSTRACT

INTRODUCTION: The aim of this study was to analyze brain functional connectivity and its relationship to cognition in patients with mild traumatic brain injury (mTBI). METHODS: Twenty-five patients with mTBI and 25 healthy control subjects were studied using resting-state functional MRI (rs-fMRI). Amplitudes of low-frequency fluctuations (ALFFs) and functional connectivity (FC) were calculated and correlated with cognition. RESULTS: Compared with the normal control group, the mTBI patients showed a significant decrease in working memory index (WMI) and processing speed index (PSI), as well as significantly decreased ALFFs in the cingulate gyrus, the middle frontal gyrus and superior frontal gyrus. In contrast, the mTBI patients' ALFFs in the left middle occipital gyrus, the left precuneus, and lingual gyrus increased. Additionally, FC significantly decreased in the thalamus, caudate nucleus, and right hippocampus in the mTBI patients. Statistical analysis further showed a significant positive correlation between the ALFF in the cingulate gyrus and the WMI (R (2) = 0.423, P < 0.05) and a significant positive correlation between the FC in the left thalamus and left middle frontal gyrus and the WMI (R (2) = 0.381, P < 0.05). CONCLUSION: rs-fMRI can reveal the functional state of the brain in patients with mTBI. This finding differed from observations of the normal control group and was significantly associated with clinical cognitive dysfunction. Therefore, rs-fMRI offers an objective imaging modality for treatment planning and prognosis assessment in patients with mTBI.