Changes in Low Frequency Fluctuations in Patients with Mild Traumatic Brain Injury: A Resting State fMRI Study

Jadwiga Rogowska¹, Piotr Bogorodzki², Melissa Lopez-Larson¹, Jace B. King¹, Deborah Yurgelun-Todd¹

The purpose of this study was to utilize rfMRI to investigate changes in low-frequency fluctuations related to mild traumatic brain injury (mTBI). Traumatic brain injury is a serious public health problem, and the neurobiological correlates of mTBI have been difficult to study. While there are several ways to examine regional spontaneous activity in resting state fMRI, in this study we used fractional amplitude of low-frequency fluctuations ALFF (fALFF), which is a fraction of ALFF in a given frequency band to the ALFF over the entire frequency range detectable in a given signal. We found that there are differences in fALFF between the two bands in many brain regions, specifically in regions associated with motor functions.The significant differences between HC and mTBI patients show that spontaneous activity in frequency bands located in frontal regions, particularly in medial frontal and anterior cingulate areas, are reduced in mTBI. These differences are important, as they demonstrate focal functional differences in the absence of task demands.