Infant Reflexes Infant Reflexes Keith Holland BSc, FCOptom, FCOVD, - PDF document

Infant Reflexes Infant Reflexes Keith Holland BSc, FCOptom, FCOVD, FAAO, DipCLP United Kingdom ICBO 2006 History History What is a reflex? What is a reflex? • At it’s most basic, a reflex is a stereotyped, • Numerous authorities have talked of the automatic response to a stimulus reflex heirarchy, including Gesel, de – e.g. simple muscle responses such as the movement Quiros, Getman, Holt, Ayres, Bobath, away from pain. Blythe and others • In the human, in addition to these basic ‘arc’ reflexes, there exist both postural and primitive • In recent years, much work on reflexes, designed to help the helpless infant in understanding the role of these reflexes on a hapless world human development has come from • These are far more complex, involving motor Blythe and Goddard of INPP in Britain conrol, midbrain and in some cases cortical involvement – but at a sub-conscious level. 1

The development of children and The development of children and • This development is largely linked to the nerves nerves maturation of the central nervous system, and would appear to be pre-programmed • Although at birth we are already from conception programmed with many complex movements, we are still by and large • Development and need go hand-in-hand helpless – we cannot move, find food or – We do not develop complex motor skills until communicate simple ones are in place – Simple motor skills are there to fulfil simple • None the less, we have already started to needs develop many complex skills in-utero that lay the foundations for the future Hierarchy of development Hierarchy of development • We see from VT that development is along a broad front – one skill depends on Foetal First Year First Decade Adulthood another maturing, and on it’s being ||||| Motor roots needed by the body to achieve a purpose |||||| Sensory roots ||| Acoustic tectum ||||Acoustic analyser – We don’t walk until we can crawl! ||||Sub-cerebellum ||||||mid-cerebellum • This development follows a clear pattern |||||||||reticular formation across the human race, and seems to be |||optic nerve & tract inextricably linked to the presence of a ||optic radiations ||||||||||acoustic radiations series of reflexes that are similar and Thalamic |||| radiations consistent in all races Intra ||||||||||||||||| Cortical associations After Robeck – The Brain 2

Hierarchy of development Hierarchy of development Primitive Reflexes Primitive Reflexes Foetal First Year First Decade Adulthood • These are automatic, stereotyped ||||| Motor roots |||||| Sensory roots Feldenstructure development movements that are directed from the ||| Acoustic tectum brain-stem and executed without cortical ||||Acoustic analyser involvement ||||Sub-cerebellum ||||||mid-cerebellum • Most are essential to survival |||||||||reticular formation – At least to effective survival |||optic nerve & tract • Primitive reflexes should ideally clear, or ||optic radiations transform into postural reflexes well before ||||||||||acoustic radiations Thalamic |||| radiations one year of age Intra ||||||||||||||||| Cortical associations After Robeck – The Brain Postural Reflexes Postural Reflexes • These are higher order automated movements, controlled by the mid-brain, indicating cortical involvement that allows FUNCTION some voluntary inhibition of otherwise STRUCTURE “automatic responses” to stimulus. • They pave the way for the dependant infant to become an independent adult 3

Adult Behaviour – – beyond reflex beyond reflex Adult Behaviour Beyond Reflexes Beyond Reflexes action action • Classically, postural reflexes are seen as the upper layer of involuntary action and • Our heritage has been to develop and development potentiate all three of these levels through vision therapy and lenses • I submit there is another, higher layer, as described by Peachey and others – those schema of action that allow automated responses to events that are sub- conscious, yet cortical in origin Lest we forget.. Lest we forget.. Four Circles Model of Vision Four Circles Model of Vision Identification Centering What are you? Where are you? Speech & Language Anti Gravity What can I tell you about it? Where am I? 4

Summary Summary Key reflexes Key reflexes Conception Conception In-utero In-utero Early life Maturity • Key Reflexes that relate to our work LIFE LIFE – MORO Cellular Reflex arcs Development – Asymmetrical tonic neck reflex And control Primitive reflexes – Tonic neck reflex Brain Stem control – Spinal gallant Postural reflexes Mid-brain control – Postural reflexes Adult Cortical – Fear Paralysis Reflex schema control Moro Moro Moro Moro • Possibly the most crucial device for kick starting • That sympathetic system stimulation results in: life in air – Release of adrenaline • Any sudden stimulus causes instantaneous – Increased breathing rate (can cause hyperventilation) arousal of the organism – Increased heart rate – Rise in blood pressure • There is a sudden expansion of the lungs • This can all be accompanied by aggression / – Followed by a momentary pause or “freeze” anger / excessive emotional outburst – And then explosive exhalation, often with a cry – Immediately following, there is a stimulation of the sympathetic nervous system 5

Moro Moro • The reflex movement itself involves the arms flying out, with the fingers open, allowing the lungs to expand • The arms then pull in across the body, causing an exhalation, usually with a cry Thus, we take our first breath of life… Moro Moro - - in the longer term in the longer term Moro Moro • The moro is usually emerging at about 11 weeks • In early days, the Moro also acts as a means of in utero, and is fully developed at birth summoning help to the helpless infant • Ideally the Moro subsides by the third month • It is like a panic alarm • If not, the child becomes hypersensitive to – All or nothing, and very ‘loud’ sudden stimuli • It can be initiated by a number of stimuli – They over-react Auditory – Loud noise – They may be emotionally over-sensitive Visual – Bright light – The constant release of adrenalin leads to draining of Tactile – Sharp touch cortisol supplies. In turn this lowers auto-immune defences, and leaves them prone to minor infections Vestibular – Sharp change in balance • Sore throats, asthma and eczema are particularly common 6

Moro – – in the longer term in the longer term Moro – – the positive side the positive side Moro Moro – Visual effects include dilated pupils and • Yes, there really is one! photosensitivity • The Moro bound individual may be:- – The child may be constantly drawn to bright or – Good at multi-tasking sudden visual stimuli, leading to figure-ground – Can go into ‘hyper-drive’ in emergencies problems, and difficulty coping with detail – Can be good at ‘explosive’ type tasks, and may be an – Auditory issues mirror vision excellent athlete (but not at the marathon!) • They overact to noise – May like ‘living on the edge’, and be good at extreme • They have difficulty coping with auditory discrimination type sports, or enjoys danger • There is a specific hearing loss at 6,000Hz Asymmetric Tonic Neck Reflex Asymmetric Tonic Neck Reflex ATNR ATNR (ATNR) (ATNR) 1 Head turn to the side • If the moro helps us breathe: ATNR helps 3 (1)causes limb on that us get out! side to extend (2), and • ATNR provides a corkscrewing action that 2 opposite limb to pull in (3) helps the head engage, and the baby to – flexion pass down the birth canal, it is activated A similar effect occurs by maternal contractions with the legs (4) 4 7

ATNR ATNR ATNR ATNR • Vision: In those crucial early days, ATNR helps • After birth, the ATNR helps ensure free air stimulate hand / eye correspondence, passage in the early weeks, and later stimulating both vergence, version AND helps prepare the body for turning over accommodation and crawling 4 in 1! – (Remember the four circles?) – 3 for 1 What an economy of action! • ATNR should clear by six months as it is no longer needed • Almost always very strong in Cerebral Palsy • The down side of retention… ATNR – ATNR – negatives negatives ATNR – ATNR – negatives negatives • ATNR and writing… • As we move to crawl, a retained ATNR – As head turns to blocks cross crawling right, so right hand – This blocks good bilateral integration pulls out to right development – Tension – In turn, this may block myelination of corpus increases, leading callosum to pressure, and • Later, can effect walking causing broken pencils ipsilateral march and poor postural stability 8

ATNR – ATNR – negatives negatives ATNR – ATNR – positives positives • Some suggest affects development of dominance Only of use in • Visually, can ‘tether’ vergence to near Australia (baby looks at hand all the time) - And if you are a – NPS & Myopia development? Koala! • May affect lateral pursuits, and later impact on reading Tonic Neck Reflex (TLR) Tonic Neck Reflex (TLR) TLR TLR Backward TLR • Closely linked to the Moro • Controlled by vestibular system • Bending forward of neck causes folding of arms & legs (forward TLR) • Extension of neck causes extension of arms & legs (backward TLR) Forward TLR 9