Effect of hypothermia on brain edema formation following intracerebral hemorrhage in rats

Abstract

Brain edema is an important clinical complication of intracerebral hematoma (ICH). Hypothermia has been employed as an effective neuroprotective treatment on cerebral ischemia and contusional brain injuries. In this study, we attempted to evaluate the effects of mild hypothermia (35 °C) on brain edema formation at 48 hours after ICH in the rat. Brain hypothermia started at 6, 12 and 24 hours after the induction of hematoma (HT6; n = 6, HT12; n = 11, HT24; n = 6). Brain water contents in the basal ganglia was significantly reduced in the rats treated with mild hypothermia compared with the normothermic rats (NT; 82.0 ± 0.04% vs. HT6; 78.6 ± 0.09%: p<0.01, HT12; 79.7 ± 0.05%: p<0.01, HT24; 79.7 ± 0.05%: p < 0.01). Differences in the brain water content were not significant among the hypothermic subgroups. The BBB disruption to Evan's blue was significantly reduced with hypothermia compared with the normothermic rats in the ipsilateral basal ganglia (42.3 ± 4.0 vs. 23.0 ± 5.2 ng/g wet tissue; p < 0.05). Hypothermic treatment tended to inhibit the accumulation of polymorphonuclear (PMN) leukocytes in the lesion compared with the normothermic treatment (0.78 ± 0.13 vs. 0.51 ± 0.16 δAbs/mg tissue). This study indicates that hypothermic treatment significantly reduces the brain edema formation after ICH in rats. © Springer-Verlag 2003.