N-Acetyl-Aspartate in the Dorsolateral Prefrontal Cortex Long After Concussion in Youth

Objective: Despite increasing interest in the neurobiological effects of concussion in youth, a paucity of information is available regarding outcomes long after injury. The objective of this study was to determine the association between a history of concussion and the putative neuronal marker N-acetyl-aspartate (NAA) in the dorsolateral prefrontal cortex (DLPFC) in youth.

Setting: Outpatient clinic in a children's hospital.

Participants: Youth with concussion (N = 35, mean = 2.63, SD = 1.07 years postinjury) and youth with a nonconcussive orthopedic injury (N = 17) participated.

Design: A cross-sectional proton magnetic resonance spectroscopy (H-MRS) study.

Main Measures: The primary outcome measure was NAA concentration in the right and left DLPFCs.

Results: We observed lower levels of NAA in the right DLPFC in youth with past concussion (F = 3.31, df = 4,51, P = .018) than in orthopedic controls but not in the left DLPFC (F = 2.04, df = 4,51, P = .105). The effect of lower NAA concentrations in the right DLPFC was primarily driven by youth with a single prior concussion versus those with multiple concussions. NAA in the left DLPFC, but not in right DLPFC, was associated with worse emotional symptoms in youth with concussion.

Conclusion: The presence of lower levels of DLPFC NAA suggests potential association of concussion in youth, although further investigation is needed, given that the result is driven by those with a single (and not multiple) concussion. Exploration of applying MRS in other brain regions is also warranted.