Total number of waves in relation to sleep. In both the non-spinal cord injury (SCI) and SCI groups, the total number of waves was significantly suppressed during the sleep phase compared to the pre-sleep phase (Pre-sleep vs Sleep, non-SCI: 98 ± 11 vs 70 ± 5, P < 0.005; SCI: 68 ± 11 vs 51 ± 2, P < 0.001), and was significantly increased after awakening from sleep (Sleep vs Arousal, non-SCI: 70 ± 5 vs 120 ± 21, P < 0.001; SCI: 51 ± 2 vs 88 ± 12, P < 0.001).