Primitive And Tonic Reflexes


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Primitive And Tonic Reflexes

  2. 2.  Normal infants are born with numerous primitive reflexes because of the unrestrained influence of the “old brain” (deep gray matter), which contains the centers for such reflexes. These centers include the brainstem, cerebellum, mid brain and basal ganglia.  The “new brain” (cerebral cortical mantle) can be viewed as an inhibitory organ: during development, primitive reflexes are inhibited and integrated into more functional, postural and voluntary motor responses.  With cerebral insults, this cortical suppression /integration is released, and various deep gray matter responses (primitive reflexes) reappear.
  3. 3. Reflexes important to examine in the patient suspected of abnormal reflex activity include:  Flexor withdrawal  Traction  Grasp  Tonic neck  Tonic labyrinthine  Positive support and  Associated reactions.
  4. 4.  Flexor withdrawal reaction is generally the simplest to observe and is judged by an overt movement response.  Tonic neck reflexes, on the other hand, bias the musculature and may not be visible through overt movement responses.  In these reflexes movement is rarely produced but rather posture is typically influenced through tonal adjustments.
  5. 5.  Capute et al in 1976 described a quantitative reflex scale for the grading reflexes: 0 : absent 1+ : transient; elicited involuntarily by passive action of the infant, or noted only by change in tone. 2+ : visible movement of extremities. 3+ : pronounced or sustained; more exaggerated than normally seen at chronological age; not readily habituated. 4+ : obligatory; infant unable to break out of reflex for a minimum of 60 sec (pathologic).
  6. 6. ASYMMETRICAL TONIC NECK REFLEX  The asymmetric tonic neck reflex is mediated ipsilaterally through the first three cervical nerve roots.  Mc Couch et al. (1951) localised the receptive field for the tonic neck reflexes to the upper neck joints, especially to the atlantoaxial and atlanto- occipital joints.  Pacella and Barera (1940) documented an influence of the ATNR on the grasp reflex with a reinforcement of the grasp reflex on the occiput side and the weakening of the grasp reflex on the face side of an ATNR.  This interaction between the two reflexes explains the occasional inclusion of finger extension/flexion in the ATNR pattern.
  7. 7. ASYMMETRICAL TONIC NECK REFLEX Onset: birth Integration: 4-6 months DESCRIPTION : When the child is supine he may be seen to lie with head turned to one side with extension of extremities on that side, and contralateral flexion of extremities. This may also be noted in sitting position. It is often described as “fencer” position. TECHNIQUE: The child is placed in supine. He is first observed for active head turning and subsequent extremity movement. If the reflex is not noted, the head is turned for 5 sec. This is repeated for five times to each side. If no movement is noted, the head turning is repeated and changes in tone are observed. This is then repeated with the child in a seated position. GRADING:  0 : Absent  1+: tone changes in extremities with head rotation. On the chin side there is increased tone on flexion. On the occiput side there is increased tone on extension. Active head rotation on the child’s part may yield slight movement of the extremities Passive movement of the head does not yield movement of the extremities.  2+: Visible extension of the extremities on the chin side and the flexion of the extremities on the occiput side. Movement is noted on both passive and active rotation of the head. (this is seen in normal development of reflex between 1 and 3 months of age.)  3+: Exaggerated quality with full extension of extremities on the chin side (180 degrees) or full flexion of extremities on occiput side (greater than or equal to 90 degrees at the elbow)  4+: Pathologic. Obligatory extension/flexion for more than 60 sec.
  9. 9. SYMMETRICAL TONIC NECK REFLEX Onset: 4-6 months Integration: 8-12 months  The symmetrical tonic reflex is analogous to the asymmetrical tonic neck reflex, but the head-on- body manipulation of the flexion extension in the midline changes the axis of differentiation from sagittal to horizontal ( i.e., there is an upper- lower rather than a right left extremity difference).
  10. 10. SYMMETRICAL TONIC NECK REFLEX DESCRIPTION : On raising the head of a prone child, extensor tone increases in the arms and flexor tone increases in the legs; flexing the neck has the opposite effect with increased flexor tone in the arms and increased extensor tone in the legs. TECHNIQUE: The child is prone , suspended, sitting or kneeling. Active neck extension/flexion is sought through visual stimulus or command. Movement or tone changes in extremities is assessed. If there is no active movement, the neck is passively extended/flexed five times and tone/movement is assessed. GRADING:  0 : Absent  1+: Mild, intermittent arm extension and leg flexion with neck extension; the reverse with neck flexion. Frequently only tone changes in the extremities with neck flexion/extension.  2+: Visible and consistent arm extension, or leg flexion with neck extension; the reverse is noted with flexion.  3+: Marked arm extension or leg flexion with neck extension, reverse with flexion. Not easily overcome by the child. Not readily habituated and present after five trials.  4+: Pathologic. Obligatory. Position remains after 60 sec.
  12. 12. TONIC LABYRINTHINE REFLEX  Magnus (1926) described the essential components of the tonic labyrinthine reflex:  There is only one position in which the extension becomes maximal: the supine position with snout about 45degrees above the horizontal plane. The extensor tone diminishes to a relative minimum if the baby is brought into the prone position with snout about 45degrees below the horizontal plane.  These reflexes are not evoked by movement but depend upon position.
  13. 13. TONIC LABYRINTHINE REFLEX  Tonic labyrinthine reflex in a supine position (TLS) demonstrates not only an increase in extensor tone, but also shoulder adduction with retraction, thus mimicking a “surrender” position.  In prone , the tonic labyrinthine reflex (TLP) consists of hip-knee flexion with shoulder protraction and further flexion.  A persistent non physiologic TLS will prevent an infant from rolling over in normal fashion.; however the history of “rolling over” before 3 months of age should make the examiner highly suspicious of a strong TL with an attendant high risk for significant motor impairment.  A marked TL may inhibit the “embrace” phase of MORO reflex.
  14. 14. TONIC LABYRINTHINE REFLEX DESCRIPTION : The posture of the limbs changes with respect to the position of head in space (orientation of the labyrinths). Supine the limb extends or extensor tone increase. Prone, the limbs flex or the flexor tone increases. TECHNIQUE: The child is observed supine. Support is then placed between the shoulders so that the head is extended to 45 degrees. The tone is assessed. The child’s head is then flexed to 45 degrees with the back supported and finally he is asked to grasp the midline. The child is then placed prone and tone is GRADING:  0 : Absent  1+: In the supine position, the shoulders are retracted and arms are lying in “surrender” posture. There would be momentary shoulder retraction and leg extension when support is placed between the shoulders and head extended. When the child is made to flex his head, shoulder retraction is broken and hands immediately come to midline. In prone there may be momentary flexion noted at the hips.  2+: With his head in extension the child is not able to overcome shoulder retraction. His hands do not come to the midline when his head is flexed, but he can overcome this on command. Prone, some degree of flexion with increased flexor tone is noted.  3+: When the child’s head is extended there is a significant shoulder retraction and leg extension. He is unable to bring his hands together fully when asked to flex his head and his shoulders do not protract. In prone there may be considerable flexion.
  16. 16. POSITIVE SUPPORT REFLEX Onset: birth Integration: 6 months  Magnus (1925) described positive supporting reaction as a mechanism necessary for maintaining erect posture.  Rademaker’s (1924) further refined its description as a simultaneous contraction of opposing muscles so as to fix the joints of the lower extremities; tactile, pressure, and proprioceptive components were used to elicit it.  He proposed it as a preparatory position for motion.  Paine( 1964) reported that its presence to a strong degree from a newborn period is common in spastic tetraparesis.  Pressure on the soles of the feet yields an anti gravity contraction of the extensor muscles producing an erect
  17. 17. POSITIVE SUPPORT REFLEX DESCRIPTION : Upon stimulation, co- contraction of the opposing muscle groups occurs so as to fix the joints of the lower extremities in a position capable of supporting weight. TECHNIQUE: The child is suspended in a vertical position and the balls of the feet are brought in contact with the floor or a surface for 60 secs. The child is then bounced five times. GRADING:  0 : Absent. No attempt at weight bearing.  1+: The child does not maintain his weight for 60 sec. he may land flatfooted with no discernible movement from heel to toe. The knees may be partially flexed without evidence of extension.  2+: The child is able to support his weight for greater than 60 sec. there is quick movement from plantar flexion to dorsiflexion. There is extremity extension with body support. Slight hip and knee flexion may be noted.  3+: There is delayed movement from plantar flexion to dorsiflexion. The child remains in equinus position. The knees may be hyper extended in a genu recurvatum position or there may be fixed and persistent knee flexion. The child seems to be standing on his toes.  4+: The child remains in equinus position. He is not able to move out of position without circumducting the legs and stays in this position for greater than 60 sec.
  19. 19. ASSOCIATED REACTIONS Onset: birth- 3months Integration: 8-9 years  STIMULUS: Resisted voluntary movement on any part of the body.  RESPONSE: Involuntary movements in a resting extremity.
  20. 20. Apeksha Besekar Ist yr. MPTh. A.I.I.P.M & R. 9.05.2013