Neuropediatrics 2006; 210 - P165
DOI: 10.1055/s-2006-946519

Arousals and behavioral state during spontaneous and induced voiding in infants

H Zotter 1, R Kerbl 1, B Urlesberger 1, G Pichler 1, W Müller 1
  • 1Klinische Abteilung für Neonatologie, Graz, A

Aims: To evaluate whether bladder voiding in healthy infants is accompanied by arousals during sleep and body movements or any changes in heart rate (HR), respiratory frequency (RF) or EEG (electroencephalogram) frequency during wakefulness. Furthermore, we imitated spontaneous bladder voiding in sleeping infants in order to find out whether arousals in sleeping infants can be induced.

Methods: Polygraphic recordings were performed in 33 healthy infants (17 female) born at term. The infants' age at study entry was 41±10 days and actual body weight was 4876±403g (mean±SD). Bladder voiding was recorded by an adapted enuresis detector which was connected to the polygraphic computer unit. Arousals and awakenings were defined as suggested by the International Paediatric Work Group on Arousals.

In order to imitate spontaneous bladder voiding during sleep, we investigated another group of 34 infants (15 female, born at term, age at study entry 56±14 days, actual body weight 5225±701g). Warm water was injected into the diaper of the sleeping infant during non-REM sleep. The exact moment of water injection was recorded by the polygraphic computer unit.

Results: Awakening was observed in 12 (36%) infants 77±9 seconds before bladder voiding. Twenty-one infants (64%) continued sleeping during bladder voiding. In sleeping infants bladder voiding occurred during non-REM sleep only, and was accompanied by a cortical arousal. During wakefulness RF was lower, HR and EEG frequency were higher, but stayed constant during bladder voiding. Induced bladder voiding was unable to cause arousals in sleeping infants.

Conclusions: Our observations demonstrate that spontaneous bladder voiding in healthy infants during sleep is accompanied by body movements, changes in HR and EEG frequency indicating cortical arousals whereas during wakefulness these changes cannot be observed. Induced bladder voiding during sleep is unable to cause arousals indicating more complex pathways.