Primitive Reflexes in the baby

Objectives : identify which of these reflexes are relevant the neurological examination of the baby, 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.

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.

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.

The levels of hierarchy in motor control CORTEX MIDBRAIN BRAINSTEM SPINAL CORD Higher order control centra Lower order control centra

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

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 baby’s gestational age (in case of prematurely born)

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

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

Clinical implications of persistence ? 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 Parkinson’s disease

Clinical implications of persistence ? 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

Clinical implications of persistence ? 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

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.

Asymmetrical Tonic Neck Reflex (ATNR)

Asymmetrical Tonic Neck Reflex (ATNR) 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

Clinical implications of persistence ? 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

Startle

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 (don’t 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

Clinical implications of persistence ? 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

Palmar Grasp When a finger/or other stimulus into the palm of the child’s 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

Clinical implications of persistence ? 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 child’s own thumb. Difficulty with releasing objects from hand Interferes with the development of grasp Difficulty with activities requiring WB on an open hand

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

Clinical implications of persistence ? 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

Flexor withdrawal

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 leg’s extensor tone increases making balance very difficult

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.

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.

Clinical implications of persistence ? 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 child’s ability to sit, poor posture (scoliosis)

Clinical implications of persistence ? 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

Automatic walking

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

Clinical implications of persistence ? 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