1575 VESTIBULAR RESPONSES TO CALORIC STIMULATION IN PREMA-TURE INFANTS AND THEIR CORRELATION WITH ACQUISITION OF HEAD CONTROL

Abstract

Premature infants are often delayed in the acquisition of head and postural control even in the absence of neuromuscular deficits. Our previous studies have shown that vestibular responses to rotation and caloric irrigation are late to mature in prematures. 13 premature infants were followed prospectively for a period of 2 years with repeated neurodevelopmental evaluations and vestibular tests, recording oculo-motor responses to rotation and cold caloric stimulation by electronystagmography. 36 full term infants were recruited and followed simultaneously. None of the infants had evidence of neuromuscular dysfunction. The time of appearance and the quality of vestibular responses recorded were compared with the time when good head control in the sitting position was acquired. Delayed head control was found in all the infants who had either delayed appearance of vestibular responses to rotation, poor caloric responses bilaterally or only a unilateral response. Among the prematures, gestational age alone did not correlate well with the time of acquisition of head control. The incidence of delayed abnormal vestibular responses was much higher in the premature babies who,as a group, also had a higher incidence of delayed head control. An excellent time correlation was found between the recording of good vestibular responses to caloric stimulation and the acquisition of head control. The study suggests that the acquisition of head control in infants is largely dependent on appropriate information from the vestibular organs.