A reflex is a muscle reaction that happens automatically in response to stimulation. Certain sensations or movements produce specific muscle responses.
The presence and strength of a reflex is an important sign of nervous system development and function.
Many infant reflexes disappear as the child grows older, although some remain throughout adulthood. A reflex that is still present after the age when it would normally disappear can be a sign of brain or nervous system damage.
Infant reflexes are responses that are normal in infants, but abnormal in other age groups. These include:
- Moro reflex
- Sucking reflex (sucks when area around mouth is touched).
- Startle reflex (pulling arms and legs in after hearing loud noise).
- Step reflex (stepping motions when sole of foot touches hard surface).
Other infant reflexes include:
Tonic neck reflex. This reflex occurs when the head of child who is relaxed and lying face up is moved to the side. The arm on the side where the head is facing reaches away from the body with the hand partly open. The arm on the side away from the face is flexed and the fist is clenched tightly. Turning the baby's face in the other direction reverses the position. The tonic neck position is often described as the fencer's position because it looks like a fencer's stance.
Truncal incurvation or Galant reflex. This reflex occurs the side of the infant's spine is stroked or tapped while the infant lies on the stomach. The infant will twitch his or her hips toward the touch in a dancing movement.
Grasp reflex. This reflex occurs if you place a finger on the infant's open palm. The hand will close around the finger. Trying to remove the finger causes the grip to tighten. Newborn infants have strong grasps and can almost be lifted up if both hands are grasping your fingers.
Rooting reflex. This reflex occurs when the baby's cheek is stroked. The infant will turn toward the side that was stroked and begin to make sucking motions.
Parachute reflex. This reflex occurs in slightly older infants when the child is held upright and the baby's body is rotated quickly to face forward (as in falling). The baby will extend his arms forward as if to break a fall, even though this reflex appears long before the baby walks.
Examples of reflexes that last into adulthood are:
- Blinking reflex -- blinking the eyes when they are touched or when a sudden bright light appears
- Cough reflex -- coughing when the airway is stimulated
- Gag reflex -- gagging when the throat or back of the mouth is stimulated
- Sneeze reflex -- sneezing when the nasal passages are irritated
- Yawn reflex - yawning when the body needs more oxygen
Causes of Infant reflexes
Infant reflexes can occur in adults who have:
- Brain damage
When to Contact a Health Professional
The health care provider will often discover abnormal infant reflexes during an exam that is done for another reason. Reflexes that remain longer than they should may be a sign of a nervous system problem.
Parents should talk to their child's health care provider if:
- They have worries about their child's development.
- They notice that baby reflexes continue in their child after they should have stopped.
What to Expect at Your Office Visit
The health care provider will perform a physical exam and ask questions about the child's medical history.
Questions may include:
- What reflexes did the baby have?
- At what age did each infant reflex disappear?
- What other symptoms are also present (for example, decreased alertness or seizures)?
Volpe, JJ. Neurological examination: normal and abnormal features. In Volpe JJ. Neurology of the Newborn. 5th ed. Philadelphia, Pa: Saunders Elsevier; 2008:chap 3.
|Review Date: 12/4/2013
Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.