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.