The relationship between bladder voiding and the brain activities during sleep in healthy preterm newborn children

Objective To explore the relationship between voiding pattern and brain activities by using video-electroencephalogram (video-EEG) in healthy preterm newborn children. Methods Twenty-eight healthy preterm neonates (16 boys and 12 girls) were recruited.Based on conceptual age (CA), the subjects were divided into three groups ofⅠ (31 weeks ≤CA<33 weeks; n=11), Ⅱ (33 weeks ≤CA<35 weeks; n=7) and Ⅲ (35 weeks≤CA<37 weeks; n=10). Video-EEG data from 8 cortical regions were recorded from 8 to 12 am.Meanwhile, voiding frequency (VF), voiding volume (VV), post-void residual volume (PRV) and status at voiding (awake/sleep) were recorded. Results A total of 91 voids were recorded. And 52.7% of all bladder voiding occurred during an awakened state.Intermittent voiding pattern (urination ≥2 every 10 min) was 13 times up to 14.3% of all voiding.VF in sleeping of group Ⅲ was significantly less than that of two other groups (2.4±1.0, 1.6±1.0, 1.0±0.9, P=0.00). PRV/BW of groupⅠwas significantly larger than those of groups Ⅱ & Ⅲ (11.1±5.6, 7.6±2.5, 6.6±4.2, P=0.02). In each group, comparing EEG amplitude during quiet sleep voiding, 5 second before and after voiding, electrode pair Fp1-T3 and Fp2-T4 amplitude showed significant difference between groups Ⅰ& Ⅱ and electrode pair C3-O1 and C4-O2 amplitude showed significant difference in group Ⅲ (P<0.05). Comparing the amplitude among three groups during quiet sleep voiding, 5 second before and after voiding, electrode pair Fp1-T3, C3-O1 and T3-O1 showed significant differences (P<0.05). EEG frequency showed no statistical differences. Conclusions During an early neonatal period, brain is involved in controlling bladder voiding.With advancing age, central brain and occipital area, especially left cerebral regions, play important roles in voiding control in preterm neonates. Key words: Micturition; Newborn; Electroencephalogram