NEONATAL REFLEXES – Everything you need to know
Domlur, Bengaluru Feb 13, 2017
Neonatal reflexes are inborn reflexes which are present at birth and occur in a predictable fashion. A normally developing newborn responds to certain stimuli with these reflexes, which eventually become inhibited as the child matures.
- Most primitive reflexes begin to occur in utero through the early months of the child’s postnatal life.
- These reflexes are then replaced by voluntary motor skills.
- When the reflexes are not inhibited, there is usually a neurological problem at hand.
- Individuals with cerebral palsy and neurogenic dysphagia, the presence of primitive reflexes is a characteristic
- Stimulated by a sudden movement or loud noise.
- A normally developing neonate will respond by throwing out the arms and legs and then pulling them towards the body (Children’s Health Encyclopedia).
- Emerges 8-9 weeks in utero, and is inhibited by 16 weeks .
- Stimulated when an object is placed into the baby’s palm.
- A normally developing neonate responds by grasping the object.
- This reflex emerges 11 weeks in utero, and is inhibited 2-3 months after birth.
- A persistent palmar grasp reflex may cause issues such as swallowing problems and delayed speech .
Babinski (Plantar) Reflex
- Stimulated by stroking the sole of the foot: –toes of the foot should fan out –the foot itself should curl in.
- Emerges at 18 weeks in utero and disappears by 6 months after birth.
Asymmetric Tonic Neck Reflex
- The child is placed on his/her back and will: –make fists –turn their head to the right.
- This reflex is present at 18 weeks in utero
- Disappears by 6 months after birth
Tonic Labyrinthine Reflex
- Arms and legs extend when head moves backward (away from spine), and will curl in when the head moves forward.
- Emerges in utero after four months, postnatally.
- The neonates back is stimulated –their trunk and hips should move toward the side of the stimulus.
- This reflex emerges 20 weeks in utero and is inhibited by 9 months.
- This turning of the torso aides in neonatal and toddler movement, such as crawling and walking.
- However, if the reflex persists, it can affect walking posture
- Neonate will make walking motions with legs and feet when held in an upright position with the feet touching the ground.
- This reflex appears at birth, lasts for 3-4 months, then reappears at 12-24 months.
- When neonate is placed on stomach, their back arches and head raises.
- Emerges at 3 months post-natally and lasts until the child is 12 months old.
- If this reflex does not occur, it is an indication of a motor development issue –generalized intellectual impairment –cerebral palsy.
- The baby’s cheek is stroked: –they respond by turning their head towards the stimulus –they start sucking, thus allowing for breastfeeding.
- This reflex is inhibited anywhere between 6 and 12 months of age. (Neonatal Reflexes)
Primitive Reflexes and Swallowing
- Some primitive reflexes interfere with achievement of swallowing. –If the Moro Reflex is strong
- There can be many interruptions with feeding if the child is constantly reacting to noises or sudden movements
A present Tonic Labyrinthine Reflex
May cause problems with the holding and/or positioning for feeding,
- Can also change the position of hypo pharynx, leaving less room in the esophagus for food to travel.
A strong Asymmetric Tonic Neck Reflex.
- Can cause constant lateral head turning which may cause problems for feeding .
Normally Persisting Reflexes
- Although it is important that many of these reflexes become inhibited as a child matures, there are also those reflexes that remain throughout a healthy person’s life.
The ‘knee-jerk’ reflex
- stimulated by a tap on the tendon located just below the knee while person is sitting •an involuntary upward swinging of the lower leg and foot is a response.
The acoustic reflex
- stimulated by loud noise.
- The stapedius muscle contracts in response to this stimulus to protect the ear from possible trauma caused by loud sounds.
The pharyngeal reflex, or ‘gag ‘reflex
What Do Abnormal or Persistent Primitive Reflexes Indicate?
- The normal emergence and inhibition of primitive reflexes is extremely important in neonates.
- However, these reflexes should disappear and allow for voluntary skills to replace them.
- Those children who exhibit abnormal reflex patterns most likely suffer from a neurological problem which can result in –dysphagia, –delayed speech –reading problems
- The reemergence of primitive reflexes in adults with a formally mature and healthy neurological system can indicate a problem in the central and/orperipheral nervous systems.
- Thus, testing for the presence of primitive reflexes in adults can determine if there may be neurological breakdown.