Regionally specific resting-state beta neural power predicts brain injury and symptom recovery in adolescents with concussion: a longitudinal study.

Mild traumatic brain injury (mTBI) is common in adolescents. Magnetoencephalography (MEG) studies (primarily reporting on adult males) have demonstrated abnormal resting-state (RS) brain activity in mTBI. The present study sought to identify RS abnormalities in male and female adolescents with mTBI (no previous mTBI and no previous DSM-5 diagnosis) identified from an outpatient specialty care concussion program setting as a basis for evaluating potential clinical utility. Visit 1 MEG RS data were obtained from 46 adolescents with mTBI (mean age: 15.4 years, 25 females) within 4 months of a mTBI (mTBI acute to sub-acute period) as well as from 34 typically developing (TD) controls (mean age: 14.8 years; 17 females) identified from the local community. Visit 2 RS data (follow-up ∼4.3 months after Visit 1; mTBI sub-chronic period) were obtained from 36 mTBI (19 females) and 29 TD (14 females) of those participants. Source-space RS neural activity was examined from 4 to 56 Hz. Visit 1 t-tests showed that group differences were largest in the beta range (16-30 Hz; mTBI < TD), with Visit 2 whole-brain linear mixed model (LMM) analyses examining beta-band group differences as a function of Visit. A main effect of Group indicated Visit 1 and 2 beta-band group differences in midline superior frontal gyrus, right temporal pole, and right central sulcus (all mTBI < TD). The group effects were large (Cohen's d values 0.75 to 1.31). Of clinical significance in the mTBI group, a decrease in mTBI symptoms from Visit 1 to 2 was associated with an increase in beta power in 4 other brain regions. Present findings suggest that RS beta power has potential as a measure and perhaps as a mechanism of clinical recovery in adolescents with mTBI.