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Assessment of early auditory and visual abilities of extremely premature infants
Insights
Extremely premature infants show early auditory and visual responses. Simple bedside tests like bell and light reflexes can assess infants under 30 weeks postconceptional age.
Area of Science:
- Neonatology
- Developmental Pediatrics
- Neuroscience
Background:
- Assessing sensory development in extremely premature infants is crucial for early intervention.
- Established methods for evaluating auditory and visual abilities in neonates are limited, especially for those born very early.
Purpose of the Study:
- To evaluate the early auditory and visual abilities of extremely premature infants.
- To determine the postconceptional age at which specific sensory responses emerge and mature.
Main Methods:
- Auditory (bell) and visual (light, optokinetic nystagmus drum) stimuli were used to assess 47 extremely premature infants.
- Infants' responses, including heart rate, respiratory rate, blinking, and nystagmus, were recorded.
- Comparison was made with 15 full-term newborn infants.
Main Results:
- Infants responded to a bell and blinked to light from 25 weeks postconceptional age (PCA).
- Habituation to bell and light stimuli was observed in most infants within a week.
- Optokinetic nystagmus was elicited from 30 weeks PCA, becoming universal by 40 weeks PCA.
Conclusions:
- Alerting to sound, blinking to light, and habituation are feasible bedside assessments for extremely premature infants (<30 weeks PCA).
- Optokinetic nystagmus is a valuable tool for assessing visual abilities in premature infants nearing term.
Abstract:
The early auditory and visual abilities of 47 extremely premature infants (31 born less than or equal to 28 weeks gestation) were assessed with a bell, a light and an optokinetic nystagmus drum. All the infants altered to the bell and blinked to the light from 25 weeks postconceptional age (PCA) and beyond. A few infants at first had only a change in heart rate or respiratory rate in response to the bell, or required a high-intensity light to elicit a blink. The majority appeared to habituate to the bell and light during their first examination at one week of age. None of the infants blinked in response to a threatening gesture. Optokinetic nystagmus could be elicited as early as 30 weeks PCA, could be elicited in the majority by 36 weeks PCA, and universally by term (40 weeks PCA). The responses of 15 fullterm newborn infants were not significantly different from those of the preterm infants at term. Alerting to a bell, blinking to light and habituation to both are simple bedside maneuvers for assessing extremely premature infants less than 30 weeks PCA. Optokinetic nystagmus may be useful in assessing the visual abilities of premature infants closer to term.