Figure 4. Quantitative histopathologic evaluation of L3, L4, and L5 spinal segments expressed as a spinal histopathologic score in all experimental groups. Similar to neurologic outcome in study 1 (A), temperature-dependent suppression of spinal neuronal degeneration was seen, with the maximum protection observed in 27 [degree sign]C hypothermic groups (sequential comparisons using the Mann-Whitney U test). Comparable to study 2 (B), better protection was afforded after 2 h of cooling compared with the 15-min cooling period at 27 [degree sign]C. In study 3 (C), no significant differences were seen in the extent of neuronal degeneration among groups (spinal histopathologic scores: 0 = no damage, 9 = > 50% gray matter damage; shaded bars represent the median).