Recovery of resting brain connectivity ensuing mild traumatic brain injury

Abstract

Brains reveal amplified plasticity as they recover from an injury. We aimed to define time dependent plasticity changes in patients recovering from mild traumatic brain injury (mTBI). Twenty-five subjects with mild head injury were longitudinally evaluated within 36 h, 3 and 6 months using resting state functional connectivity (RSFC). Region of interest (ROI) based connectivity differences over time within the patient group and in comparison with a healthy control group were analyzed at p < 0.005. We found 33 distinct ROI pairs that revealed significant changes in their connectivity strength with time. Within 3 months, the majority of the ROI pairs had decreased connectivity in mTBI population, which increased and became comparable to healthy controls at 6 months. Within this diffuse decreased connectivity in the first 3 months, there were also few regions with increased connections. This hyper connectivity involved the salience network and default mode network within 36 h, and lingual, inferior frontal and fronto-parietal networks at 3 months. Our findings in a fairly homogenous group of patients with mTBI evaluated during the 6 month window of recovery defines time varying brain connectivity changes as the brain recovers from an injury. A majority of these changes were seen in the frontal and parietal lobes between 3 and 6 months after injury. Hyper connectivity of several networks supported normal recovery in the first 6 months and it remains to be seen in future studies whether this can predict an early and efficient recovery of brain function.

Detection of Mild Traumatic Brain Injury by Machine Learning Classification Using Resting State Functional Network Connectivity and Fractional Anisotropy

“…Connectivity changes associated with the DMN and the precuneus has been observed before. 32,49 Dysfunctions associated to the DMN are found in a variety of conditions 50 and are likely to be present in the cohort of this study. Four of the significant changes in rsFNC observed in our analysis involved connectivity between cerebellum and sensorimotor RSNs.…”

Preliminary findings of altered functional connectivity of the default mode network linked to functional outcomes one year after pediatric traumatic brain injury

“…27 While to date, most longitudinal studies examining an overlapping cohort of individuals with TBI have followed individuals only through the subacute stages of recovery (i.e., up to three months post-injury), in a recent study, adults with mild TBI were followed for six months post-injury; similar to our findings, changing connectivity patterns were observed over time following injury, lending further support to evolution of functional connectivity during TBI recovery. 43 …”

Small world properties changes in mild traumatic brain injury

“…There has been tremendous progress made of the connectivity studies in MTBI for the past several years, including more heterogeneous patients population, different disease stages including acute and recovery, multiple imaging metrics including DTI, EEG, blood flow, metabolism (MR spectroscopy), and large‐scale network studies . It has been generally accepted that small‐worldness nature of brain networks is dynamically appealing and robust.…”

“…There has been tremendous progress made of the connectivity studies in MTBI for the past several years, including more heterogeneous patients population, different disease stages including acute and recovery, multiple imaging metrics including DTI, EEG, blood flow, metabolism (MR spectroscopy), and large-scale network studies. [31][32][33][34][35][36] It has been generally accepted that small-worldness nature of brain networks is dynamically appealing and robust. It is not surprising that higher small-worldness (i.e., higher local efficiency but lower global efficiency) was found in MTBI patients in comparison to controls, possibly to maintain dynamic equilibrium efficiency after injury.…”