The secondary injury and related complications after trauma
are still the focus of trauma
research. However, whether the remote effects on the central nervous system could be induced by high-energy missile extremity impact remains unclear. Also, the possible biomarker for brain damage in traumatic stress disorder
has not been determined.
Forty-two healthy adult dogs were divided into three groups: the control group (n = 12), the high-speed trauma
group (n = 15), and the low-speed trauma
group (n = 15). Bilateral thighs of dogs were wounded with a smoothbore 6.2-mm rifle at a speed of 1,368 m/s (1.03-g steel bullet) for the high-speed trauma
group and 625 m/s for the low-speed trauma
group. The expression of myelin basic protein (MBP) in cerebrospinal fluid (CSF), hypothalamus and hippocampus of the limbic system
, and temporoparietal cortex was investigated by enzyme-linked immunosorbent assay and dot-blot analysis. Also, the ultrastructure
of the above areas was observed with light and electron microscopy.
Neuronal degeneration and nerve fiber demyelination were seen in the hypothalamus and hippocampus in the high-speed trauma
group at 8 hours after impact. The MBP level was markedly increased in the CSF (p
< 0.01) in the two trauma
groups, in the hypothalamus of the low-speed trauma
< 0.05), and in both the hypothalamus and the hippocampus of the high-speed trauma
< 0.01). The expression of MBP mRNA was also significantly enhanced in these areas at the same time. The increase of MBP content in the CSF was positively correlated with the elevation of MBP concentration in the hypothalamus and hippocampus.
The hypothalamus and hippocampus of the limbic system
in the central nervous system are vulnerable to damage after high-energy missile extremity impact, indicating that it might be one of the important pathologic bases involved in the development of trauma
-related complications. Meanwhile, the MBP level in the CSF may be a sensitive biological indicator for brain damage at the early stage of trauma
-related stress disorder