Decrease in N-Acetylaspartate Following Concussion May Be Coupled to Decrease in Creatine

Objectives: To assess the time course changes in N-acetylaspartate (NAA) and creatine (Cr) levels in the brain of athletes who suffered a sport-related concussion. Participants: Eleven nonconsecutive athletes with concussive head injury and 11 sex-and age-matched control volunteers Main outcome measures: At 3, 15, 30, and 45 days postinjury, athletes were examined by proton magnetic resonance spectroscopy for the determination of NAA, Cr, and choline (Cho) levels. Proton magnetic resonance spectroscopic data recorded for the control group were used for comparison. Results: Compared with controls (2.18 +/- 0.19), athletes showed an increase in the NAA/Cr ratio at 3 (2.71 +/- 0.16; P <.01) and 15 (2.54 +/- 0.21; P <.01) days postconcussion, followed by a decrease and subsequent normalization at 30 (1.95 +/- 0.16, P <.05) and 45 (2.17 +/- 0.20; P < .05) days postconcussion. The NAA/Cho ratio decreased at 3, 15, and 30 days postinjury (P < .01 compared with controls), with no differences observed in controls at 45 days postconcussion. Compared with controls, significant increase in the Cho/Cr ratio after 3 (+ 33%, P < .01) and 15 (+ 31.5%, P < .01) days postinjury was observed whereas no differences were recorded at 30 and 45 days postinjury. Conclusions: This cohort of athletes indicates that concussion may cause concomitant decrease in cerebral NAA and Cr levels. This provokes longer time for normalization of metabolism, as well as longer time for resolution of concussion-associated clinical symptoms.