A nurse is observing a newborn for signs of neonatal neck righting reflex.
The nurse gently turns the newborn’s head to one side and observes the response.
What should the nurse expect to see if the reflex is present?
A.
The newborn’s arm and leg on the same side as the head extend, while the opposite side flex.
B.
The newborn’s arm and leg on the opposite side as the head extend, while the same side flex.
C.
The newborn’s arm and leg on both sides extend and then flex.
D.
The newborn’s arm and leg on both sides flex and then extend.
The Correct Answer and Explanation is:
The correct answer is A. The newborn’s arm and leg on the same side as the head extend, while the opposite side flex.
Explanation:
The neonatal neck righting reflex, also known as the asymmetric tonic neck reflex (ATNR), is a primitive reflex observed in newborns. It is essential for assessing neurological function and development. The reflex is typically present from birth and usually disappears by 6 months of age as the infant’s motor control matures. This reflex plays a role in the development of hand-eye coordination and body awareness.
When the nurse gently turns the newborn’s head to one side, the reflex causes the arm and leg on the side to which the head is turned (the ipsilateral side) to extend. Simultaneously, the arm and leg on the opposite side (the contralateral side) flex. This reflexive pattern resembles a “fencer’s position” and is a normal response in infants.
The asymmetric tonic neck reflex helps infants develop the ability to roll over and plays a role in their early motor development. The purpose of this reflex is to begin establishing connections between sensory inputs (the head turning) and motor responses (the movement of the arms and legs).
The presence of the reflex indicates proper neurological development. However, if this reflex persists beyond the typical age range (6 months), it may signal developmental delays or neurological issues such as cerebral palsy. A lack of this reflex in a newborn could indicate an abnormality in the nervous system and requires further evaluation.
In summary, the correct response to turning the newborn’s head to one side is the extension of the arm and leg on the same side, while the opposite side flexes. This reflects the normal ATNR, which is a critical part of infant neurological assessments.