Auditory arousal thresholds of normal and near-miss SIDS infants.

The sleep characteristics and auditory arousal thresholds of 20 near-miss sudden infant death syndrome (SIDS) infants and 97 age- and sex-matched normal infants were studied. It was observed that spontaneous arousals occurred significantly less frequently in the near-miss SIDS infants. In both groups, induced arousals occurred at comparable stimulation intensities, and arousal thresholds decreased significantly from the 44th to the 52nd postconceptional week. This supports the notion that both groups present a similar maturational process within the auditory pathways and brainstem, and that arousal is not related to differences in behavioural response to ambient noise during sleep.