Reflexes present in infants


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Reflexes present in infants

  1. 1. Presented by:Piyush VermaMDS 2nd yrDept of Paedodontics & Preventive Dentistry
  2. 2. Contents Introduction Reflex arc Classification of reflexes Significance of reflexes Types of reflexes Conclusion
  3. 3. Introduction A reflex is an involuntary or automatic action that yourbody does in response to something without evenhaving to think about it Neonatal reflexes – inborn reflexes present at birth &occur in a predictable fashion Normally developing newborn should respond tocertain stimuli with these reflexes
  4. 4. Reflex arc Anatomical pathway for a reflex iscalled as reflex arc It has 5 components : Receptor Afferent nerve Center Efferent nerve Effector organ
  5. 5. Classification of reflexes Depending upon whether inborn or acquired Unconditioned reflexes, inborn reflex Conditioned reflexes/acquired reflexes
  6. 6.  Depending upon the situation of the center Cerebellar reflexes Cortical reflex Midbrain reflex Bulbar or medullary reflexes Spinal reflexes
  7. 7.  Depending upon the purpose Protective/flexor reflexes Antigravity/extensor reflexes Depending upon clinical basis Superficial reflexes Mucus membrane Cutaneous reflex Deep reflexes Visceral reflexes Pathological reflexes
  8. 8. Significance of reflexes Helps a paedodontist to identify whether the child isdeveloping normally or not Tells about what abnormalities the child may behaving if all reflexes are not proper Knowledge of development of motor skills – helps toidentify whether development is going on at a properrate or not
  9. 9. Types of reflexes
  10. 10. General body reflexes : Moro reflex/Startle reflex Palmar/grasp reflex Plantar grasp reflex Walking/stepping reflex Limb placement reflex Asymmetric tonic neck reflex Symmetric tonic neck reflex Babinski’s reflex Babkin reflex Parachute reflex Landau reflex
  11. 11.  Withdrawal reflex Trunk incurvation reflex Tendon reflexes Gallant’s reflexTonic labyrinthine reflexFacial reflexes : Nasal reflex Blink reflex Doll’s eye reflex Auditory orienting reflex
  12. 12. Oral reflexes : Rooting reflex Sucking reflex Swallowing reflex Gag reflex Cry reflex
  13. 13. General body reflexes Moro reflex/ startle reflex Begins at 28 weeks of gestation Initiated by any sudden movement ofthe neck Elicited by -- pulling the baby halfwayto sitting position from supine &suddenly let the head fall back Consists of rapid abduction & extensionof arms with the opening of hands,tensing of the back muscles, flexion ofthe legs and crying
  14. 14. Within moments, the arms come together again Clinical significanceIts nature gives an indication of muscle toneFailure of the arms to move freely or the hands to openfully indicates hypotonia.It fades rapidly and is not normally elicited after 6months of age.
  15. 15.  Palmar/grasp reflex Begins at 32 weeks of gestation Light touch of the palm producesreflex flexion of the fingers Most effective way -- slide thestimulating object, such as a fingeror pencil, across the palm from thelateral border Disappears at 3-4 months Replaced by voluntary grasp at 45months
  16. 16.  Clinical significance Exceptionally strong grasp reflex -- spastic form of cerebralpalsy & Kernicterus May be asymmetrical in hemiplagia & in cases of cerebraldamage Persistence beyond 3-4 months indicate spastic form ofpalsy
  17. 17.  Plantar/grasp reflex Placing object or finger beneath thetoes causes curling of toes around theobject Present at 32 weeks of gestation Disappears at 9-12 months• Clinical significance : This reflex is referred to as the"readiness tester". Integrates at the same time thatindependent gait first becomespossible.
  18. 18.  Walking/steppingreflex When sole of foot is pressedagainst the couch, baby tries towalk Legs prance up & down as if babyis walking or dancing Present at birth, disappears atapprox 2-4 months With daily practice of reflex,infants may walk alone at 10months
  19. 19. Clinical significancePremature infants will tend to walk in a toe-heelfashion while more mature infants will walk in aheel-toe pattern.
  20. 20.  Limb placement reflex When the front of the leg below theknee or the arm below the elbow isbrought into contact with the edgeof a table, child lifts the limbs overthe edge Present at birth, fades away rapidlyin early months of life• Clinical significance Reflex is readily demonstrable in thenewborn and persistent failure toelicit it at this stage, is thought toindicate neurological abnormality
  21. 21.  Withdrawal reflex Protective reflex Stimulus : a pinprick or a sharppainful stimulus to sole of foot Response : flexion & withdrawal ofstimulated leg Present at birth, persists throughoutlife Clinical significance – Absence ofthis is seen in neurologically impairedinfants.
  22. 22.  Asymmetric tonic neck reflex Most evident between 2-3 months of age• Clinical significance The reflex fades rapidly and is not normallyseen after 6 months of age. Persistence is the most frequently observedabnormality of the infantile reflexes ininfants with neurological lesions Greatly disrupts development
  23. 23.  Symmetric tonic neckreflex Extension of the head causesextension of the fore limbs andflexion of the hind limbsEvident between 2-3 months of age Clinical significance Not normally easily seen or elicited innormal infants May be seen in an exaggerated formin many children with cerebral palsy.
  24. 24.  Babinski’s reflex Stimulus consists of a firm painful strokealong the lateral border of the sole from heelto toe Response consists of movement (flexion orextension) of the big toe and sometimesmovement (fanning) of the other toes Present at birth, disappears at approx 9-10months Presence of reflex later may indicate disease
  25. 25.  Babkin reflex Deep pressure applied simultaneouslyto the palms of both hands while theinfant is in supine position Stimulus is followed by flexion orforward bowing of the head, opening ofthe mouth and closing of the eyes Fades rapidly and normally cannot beelicited after 4 months of age.
  26. 26. • Clinical significance Reflex can be demonstrated in the newborn, thus showinga hand-mouth neurological link, even at that early stage
  27. 27.  Parachute reflex Reflex appears at about 6-9 months &persists thereafter Elicited by holding the child in ventralsuspension & suddenly lowering him to thecouch Arms extend as a defensive reaction• Clinical significance Absent or abnormal in children withcerebral palsy Would be asymmetrical in spastichemiplagia
  28. 28.  Landau reflex Seen in horizontal suspension with thehead, legs & spine extended If the head is flexed, hip knees &elbows also flex Appears at approximately 3 months,disappears at 12-24 months• Clinical significance Absence of reflex occurs in hypotonia,hypertonia or mental abnormality
  29. 29.  Trunk incurvation reflex Stroking one side of spinal columnwhile baby is on his abdomen causes Crawling motion with legs Lifting head from surface Present in utero, seen atapproximately 3rd or 4th day Persists for 2-3 months
  30. 30.  Gallant’s reflex Firm sharp stimulation along sides ofthe spine with the fingernails or a pinproduces contraction of the underlyingmuscles and curving of the back. Response is easily seen when the infantis held upright and the trunkmovement is unrestricted Best seen in the neonatal period andthereafter gradually fades.
  31. 31.  Tendon reflexes Simple monosynaptic reflexes, which are elicited by asudden stretch of a muscle tendonOccurs when the tendon is tappedPresent throughout life
  32. 32. Spinal cord levels of the tendon reflexes
  33. 33.  Clinical significance Useful diagnostically for :Detection of upper motor neuron lesions (exaggeratedresponse)Myopathic conditions (depressed or absent response)Localization of the segmental lesions of the cord.
  34. 34.  Tonic labyrinthine reflex Labyrinths -- most important organsconcerned with the development ofanti-gravity postures and balance Movement of the head in anydimension stimulates the labyrinths;and produces the appropriateresponses Arms & legs extend when head movesbackwards, & will curl in when thehead moves forward Emerges in utero until approximately4 months postnatally
  35. 35. Facial reflexes Nasal reflex Stimulation of the face or nasal cavity with water or localirritants produces apnea in neonates Breathing stops in expiration with laryngeal closure ininfants – bradycardia & lowering of cardiac output Blood flow to skin, splanchnic areas muscles & kidneydecreases Flow to the heart & brain remains protected
  36. 36.  Blink reflex A bright light suddenly shone into the eyes, a puff of airupon the sensitive cornea or a sudden loud noise willproduce immediate blinking of the eyes Purpose – to protect the eyes from foreign bodies & brightlight May be associated tensing of the neck muscles, turning ofthe head away from the stimulus, frowning and crying Reflexes are easily seen in the neonate and continue to bepresent throughout life
  37. 37.  Clinical significance Examination is a part of some neurological exams,particularly when evaluating comaSatisfactory demonstration of these reflexes indicate – No cerebral depression Contraction of appropriate muscles in response
  38. 38.  Doll’s eye reflex(Oculocephalic reflex) Passive turning of the head ofthe newborn leaves the eye“behind” A distinct time lag occurs beforethe eyes move to a new positionin keeping with the head position Disappears at within a week ortwo of birth Failure of this reflex to appearindicates a cerebral lesionHeadEye
  39. 39.  Auditory orienting reflex A sudden loud and unpleasant noise : May produce the blink reflex Infant may remain still and show increased alertness Quieter sounds usually cause reflex eye and head turning to theside of the sound, as if to locate it Seen first at about 4 months of age Thereafter, head turning towards sound stimuli occurs and theaccuracy of localization increases rapidly by 9-10 months
  40. 40.  Clinical significance Reflex responses are made use of in tests of infants forhearing loss Pattern of the localization responses indicates the level ofneurological maturity
  41. 41. Oral reflexes Rooting reflex Baby’s cheek is stroked : They respond by turning their headtowards the stimulus They start sucking, thus allowing forbreast feeding When corner of mouth is touched, lowerlip is lowered, tongue moves towards thepoint stimulated When finger slides away, head turns tofollow it When center of lip is stimulated, lipelevates
  42. 42.  Onset -- 28 weeks IU Well established – 32-34 weeks IU Disappears – 3-4 months Clinical significancePersistence can interfere with sucking Absence of this is seen in neurologically impairedinfants.
  43. 43.  Sucking / Swallowingreflex Touching lips or placing something inbaby’s mouth causes baby to drawliquid into mouth by creating vacuumwith lips, cheeks & tongue Onset – 28 weeks IU Well established – 32-34weeks IU Disappears around 12 months
  44. 44. Clinical significance :Persistence may inhibit voluntary suckingSigmund Freud - Any kind of deprivation of theactivity will lead to fixation resulting in oral habits
  45. 45.  Gag reflex(Pharyngeal reflex) Seen in 19 weeks of IU life Reflex contraction of the backof the throat Evoked by touching the roof ofthe mouth, the back of thetongue, the area around thetonsils and the back of thethroat
  46. 46.  Functional significance It, along with reflexive pharyngeal swallowing, preventssomething from entering the throat except as part ofnormal swallowing and helps prevent choking Clinical significance Absence of the gag reflex -- symptom of a number ofsevere medical conditions : Damage to the glossopharyngeal nerve, the vagus nerve, Brain death.
  47. 47.  Cry reflex Non conditioned reflex whichaccounts for its lack of itsindividual character Sporadic in nature Starts as early as 21-29 weeks of IUlife
  48. 48.  Importance of cry It is infant’s first verbal communication Can be interpreted as a message of urgency or distress Indicates: Hunger Pain Discomfort
  49. 49. ConclusionAppropriate knowledge of reflexes enables a paedodontist to identify whether the child is developing normally ornot to identify whether development is going on at a properrate or not Knowledge of abnormalities if all reflexes are not proper
  50. 50. References Shobha Tandon. Textbook of Paedodontics MS Muthu. Paediatric Dentistry, Principals & practice