Cerebrospinal fluid monoamine metabolites and glucose metabolism in posttraumatic aggression.

BACKGROUND

This pilot study was conducted to determine if aggressive, post brain-injured patients have abnormal glucose metabolism or abnormal CSF monoamine metabolite concentrations as compared with non-aggressive, post brain-injured controls.

METHODS

Subjects with a history of traumatic brain injury underwent a lumbar puncture and glucose tolerance test after a three-week medication wash-out period. Monoamine metabolite concentrations and glucose nadirs were compared between aggressive and control subjects.

RESULTS

There were no statistical differences between the aggressive (n = 4) and control (n = 6) group with respect to age (28.5 +/- 15.7 versus 28.0 +/- 10.8), weight (72.5 kg +/- 14.1 versus 67.7 kg +/- 10.1) or number of months since brain injury (31.8 +/- 26.1 versus 33.3 +/- 23.3). There were no significant differences between the two groups in glucose nadirs following oral glucose challenge or in levels of CSF monoamine metabolite concentrations of 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA), or 3-methoxy-4-hydroxyphenylglycol (MHPG), although a trend toward significance was noted between the MHPG groups (higher MHPG within aggressive group).

CONCLUSIONS

The preliminary data suggest that glucose metabolism and CSF monoamine metabolite concentrations do not differ significantly from aggressive subjects to controls in persons with brain injury. Follow-up prospective studies with larger sample sizes are needed to evaluate these preliminary findings.