Robyn Smith Department of Physiotherapy UFS 2012 Primitive
Reflexes in the baby
Slide 2
Objectives for the lecture: After this lecture the learner
should be: familiar with the primitive reflexes present in the baby
at birth, identify which of these reflexes are relevant the
neurological examination of the baby, be able to explain the role
of the primitive reflexes, be able to explain the
disappearance/integration of these reflexes, be able to explain the
clinical significance of the reappearance or persistence of the
primitive reflexes.
Slide 3
Background Primitive reflexes start to emerge during the late
foetal period, Most of these reflexes are already present at birth
e.g. Rooting and sucking reflex These reflexes are of sub-cortical
origin, arising mainly in the brainstem and to some degree in the
Spinal Cord.
Slide 4
Background The majority reflexes are integrated/ disappear by
the age of 6/12 (at latest by 12/12) due to the increasing
inhibitory effect of the maturing cortex. Those with protective
value tend to persist throughout life. The persistence or
reappearance of these primitive reflexes after the age of 6/12 is
abnormal and usually indicative of cortical or cerebral damage.
These reflexes lock the child in a holding pattern and their
development becomes stuck, significantly impair their development
of postural control, achievement of milestones and volitional
movement.
Slide 5
CORTEX MIDBRAIN BRAINSTEM SPINAL CORD The levels of hierarchy
in motor control Higher order control centra Lower order control
centra
Slide 6
Background Some typical developing children continue to have
persistent primitive reflexes e.g. ATNR, which are strongly
associated with developmental challenges such as dyslexia,
dyspraxia and hyperactivity
Slide 7
Eliciting of the primitive reflexes Why do we test these
primitive reflexes in the neonate? Evaluate the developmental
status and the integrity of the neurological system in the newborn
Can give an indication of the babys gestational age (in case of
prematurely born)
Slide 8
Eliciting of the primitive reflexes In some cases e.g. moro,
the reflex can be used to evaluate symmetry and could help identify
possible unilateral pathology of the nervous system e.g. obstetric
brachial plexus injury Eliciting these reflexes in the neonate is
closely related to the hunger status and alertness of the baby e.g.
often hard to elicit if baby is sleeping
Slide 9
Classification of primitive reflexes Primitive Reflexes are
divided into 3 groups : Functional significance (help birth
process) Protective value e.g. flexor withdrawal, crossed extensor
Early postural reactions e.g. moro and startle
Glabellar tap Tap the child with your finger on the forehead
just above nose. He blinks/closes eyes (protective value) Appears
at 32 weeks gestation Clinical implications of persistence ?
persistence of this reflex associated Parkinsons disease
Slide 12
Rooting reflex Elicited by gently touching the top lip, and
area of the facial with your finger. The baby will turn his head in
the direction of the stimulus and open his mouth Reflex appears
around 24-28 weeks and disappears around 3-4 months Clinical
implications of persistence ? persistence of the reflex may
contribute towards a drooling, hypersensitivity in the mouth and on
the lips contributing factor in dyspraxia
Slide 13
Sucking reflex Elicited by placing a clean gloved finger,
bottle teet or dummy in the mouth and onto the tongue The stimulus
in the mouth should elicit a sucking reflex Clinical implications
of persistence ? premature babies often have a weak suck reflex and
subsequently need tube feeding
Slide 14
Asymmetrical Tonic Neck Reflex (ATNR) Elicited head is turned
to the side and kept there for 15 seconds (position of the head is
the eliciting stimulus) The child assumes a fencing position The
arm and leg on the side of the skull remain in flexion, whilst the
arm and the leg on the face side extend. If the child does not
revert to a normal symmetrical position within seconds this is to
be considered an abnormal reflex.
Slide 15
Asymmetrical Tonic Neck Reflex (ATNR)
Slide 16
Reflex is less obvious during the first month, becoming more
obvious during months 2-4. Should have disappeared by 6 months
Clinical implications of persistence ? Difficulty in visual
pursuits (tracking) Impaired development bilateral hand function
(midline),writing problems, dyslexia Asymmetry & deformities
(spine/limbs) or even hip dysplasia (sublexation) Impaired
development in prone (crawling) Hand-eye co-ordination difficulties
Balance difficulties in sitting
Slide 17
Startle Elicited by a loud noise or by tapping on the sternum
Abduction of the arms with flexion of the elbows and adduction of
the fingers is noted. Clinical implications of persistence ? over
exaggerated in case of neurological injuries e.g. CP poor balance
in sitting
Slide 18
Startle
Slide 19
Moro Vestibular reflex elicited by sudden movement of the head
Tested on a padded surface e.g. on crib cushion or foam mat Child
is held at a 45 degree angle to the supporting surface. The head is
then lifted up slightly. Allow the head to suddenly fall a couple
of centimetres before immediately supporting the head again (dont
allow head to make contact with the padded surface though !!!) A
sudden abduction, extension of the arms associated with the
spreading of the fingers is observed. Followed by and embracing
action of adduction and flexion as the arms return to the normal
position This reflex is usually integrated by 3-4 months
Slide 20
Moro Clinical implications of persistence ? Over exaggerated in
case of some neurological conditions e.g. CP Hypotonia
neuromuscular defects may be considered if this reflex is decreased
o absent in young baby Asymmetry may indicate an obstetric brachial
plexus injury Difficulty in transitioning and poor balance in
positions like sitting Child is uncertain about their own
reactions, fearful of positional change Can be elicited by sound,
light, temperature changes and movement
Slide 21
Palmar Grasp When a finger/or other stimulus into the palm of
the childs hand stimulating the palm on the lateral aspect Fingers
flex and the child firmly grasps the hand. Hand will relax and open
directly after reaction occurred Integrated by 2 -3 months of age
Pathological if tonic part of the reflex (flexion ) persists
Slide 22
Palmar Grasp Clinical implications of persistence ? In some
children this reflex is elicited as soon as something is brought
into contact with the hand and even in some cases the childs own
thumb. Difficulty with releasing objects from hand Interferes with
the development of grasp Difficulty with activities requiring WB on
an open hand
Slide 23
Plantar Grasp Elicited by pressing on the sole of the foot near
the base of the toes. The toes and the ball of the foot curl around
the finger Present at birth and disappears by 3 months
Slide 24
Flexor withdrawal Elicited when a painful stimuli applied (pin
prick) e.g. sole of the foot is pricked or stimulated with a sharp
object In response the leg is flexed in a mass pattern. This is a
protective reflex Already present at birth, and never disappears
Clinical implications of persistence ? over exaggerated in some
children with CP, any stimulation under foot results in flexor
withdrawal. This negatively impact on WB and locomotion toe clawing
during gait
Slide 25
Flexor withdrawal
Slide 26
Crossed Extensor Reflex Flexion of one leg may be accompanied
by extension opposite leg Strengthens the limb support on the
weight bearing leg. Prevents the person from falling over Clinical
implications of persistence ? When overactive as is sometimes case
with children with CP it negatively impacts on gait. When the one
leg is in the swing through phase of gait, the weight bearing legs
extensor tone increases making balance very difficult
Slide 27
Positive support reflex Elicited when placing weight on the
sole of the foot or pressure is given against the sole of the foot
resulting in extension of legs Clinical implications of persistence
? Pattern of extensor spasticity is strengthened and stimulated. If
overactive it interferes with gait, co- contraction in the limb
results in the leg being rigidly extended.
Slide 28
Spinal gallant reflex Reflex emerges at 20 weeks gestation and
should be inhibited by 3-9 months Suggested that this reflexes aids
the birth process Elicited by holding the baby in ventral
suspension. Pull your finger down the lateral side of the back
muscles unilaterally. The spine and torso curve towards the side
where the fingers are.
Slide 29
Spinal gallant reflex Clinical implications of persistence ?
Absence of this reflex can be valuable in determining sensory loss
in the case of a myelomenigiocele Persistence of this reflex can
affect the childs ability to sit, poor posture (scoliosis)
Slide 30
Automatic walking Baby held supported under axillas with the
soles of the feet on a firm, flat supporting surface The baby
automatically steps one foot in front of the other Present at birth
but disappears within 4-6 weeks after birth Clinical implications
of persistence ? In children with CP can still observe this reflex
when holding the child up, do not confuse with voluntary gait
Slide 31
Automatic walking
Slide 32
Parachute reflex Elicited by holding the baby in ventral
suspension with the head down, extension of the arms should occur
to protect the head This is a protective reflex and appears at six
moths and never disappears
Slide 33
Landau reflex Elicited by holding the baby in ventral
suspension The child will extend his head and legs. This reflex
appears at 3 months and disappears by 1 year of age. Clinical
implications of persistence ? In children with myelomenigeocele no
extension of the legs occurs
Slide 34
References Images courtesy of GOOGLE (2012) PA Henning.
Ondersoek van die pasgebore baba. Costerus, PJ. 2003. Zooming in on
reflexes.
