EXCITATORY AMINO-ACIDS IN CEREBROSPINAL-FLUID AND THEIR RELATIONS WITH CLINICAL-FEATURES AND OUTCOMES IN ACUTE HEAD-INJURY

Objective To determine the contents and dynamics of excitatory amino a cids (EAAs), glutamate (GLU) and aspartate (ASP) in the cerebrospinal fluid (CSF) of patients with acute head injury and to clarify the rela tionship of EAAs with clinical features and outcomes. Methods Forty-tw o adults with acute head injury were included. Glasgow coma scale (GCS ) obtained at admission and Glasgow outcome scale (GOS) obtained three months post-injury were assessed. Samples of CSF were obtained via ve ntricular or lumbar puncture every 24 hours. GLU and ASP in CSF were a nalyzed by reversed-phase HPLC with a fluorescent detector. Nine contr ol subjects were adults with lumbar anesthesia but without neurologica l diseases. Results The peak concentration of GLU and ASP of head-inju red group was significantly higher than that of the control group. Dyn amic research on severely injured ones indicated that the peak value o f GLU mostly appeared within 48 hours post-injury; it decreased with t he improving or remaining of the neurological status, and increased wi th the deterioration, but was still higher than that of the control se ven days post-injury. The peak value of EAAs of severely injured patie nts was conspicuously higher than that of mildly injured group. There was a significant negative correlation between the peak values of GCS and EAAs. The peak value of EAAs in patients with poor outcome was rem arkably higher than that in patients with good outcome. GOS was closel y correlated to the peak value of EAAs. When the concentration of GLU was over 7 mu mol/L, the rate of poor-outcome increased markedly. Conc lusion The content of EAAs in CSF increases following acute head injur y and remains higher at least a week post-injury in severely injured p atients. The more severe the trauma, the more obvious the excitotoxici ty induced by EAAs; the more serious the secondary brain insult and th e brain edema will be, the worse the outcome, naturally.