Children, as opposed to adults, are characterized by a continuous process of growth and neuromotor development. The maturation of central nervous system is characterized by coordination of motor activity and as infants grow they respond to their environment in a purposeful manner with the help of special senses (acoustic and auditory inputs), integrity of labyrinthine, vestibular and musculoskeletal systems. Children achieve neuromotor mile stones of development at predictable ages within a narrow range of few weeks or months.
Development is dependent upon interaction between innate genetic potential and environmental factors like emotional security, love and attention, stimulating home environment, optimal nutrition, ethnic and cultural factors. Neuromotor retardation may occur due to gestational immaturity, perinatal hypoxia, birth trauma, metabolic disorders (inborn errors of metabolism), hypoglycemia, kemicterus, intrauterine infections, postnatal CNS infections, hypothyroidism, developmental and chromosomal disorders.
Principles of Development
1. It is the most distinctive attribute of childhood and is a continuous process from conception to maturity.
2. Development is intimately related to the maturation of central nervous system.
3. The sequence of development is identical in all children but the rate of development varies from child to child.
4. The generalized mass activity of early infancy is replaced by specific and subtle individual responses. It is a common observation that when shown a bright object, an infant shows wild excitement by moving trunk, arms, legs and babbling while an older child merely smiles and reaches for the object.
5. The development proceeds in a cephalo-caudal direction. The infant initially develops head control fol lowed by ability to grasp, sitting, crawling, standing, walking etc.
6. Certain primitive reflexes like grasp reflex and walking reflex must be lost before corresponding voluntary movements are acquired.
7. The development of language is early and advanced in girls as compared to boys.
8. Timing of dentition is unreliable for assessment of neuromotor development.
9. The child with odd-looking face does not necessarily have associated mental subnormality.
10. The attributes like creativity, future potentiality, IQ and mental superiority cannot be predicted in an individual child by developmental assessment.
Methods of Assessment
A large number of methods have been standardized to assess the development of children. They demand the availability of skilled clinical psychologist and specialized kits for reliable assessment. Gessel development evaluates gross motor, fine motor, social, adaptive and language behaviour. Amiel-Tison method of assessment pays special attention to muscle tone (active and passive), neurosensory responses (visual and acoustic) and neurobehavioural assessment. Vineland and Raval’s social maturity scale assesses the social and adaptive mental development. The other methods of neuromotor assessment include Bayley scales of infant development (motor and mental), Brazelton neonatal behaviour scale, Vojta technique (postural reactions and central coordination) and Denver developmental screening test (DDST). Among these, Bayley scales of infant development (BS1D), is most popular and widely practised. It requires the services of a highly trained examiner and takes 45 minutes to administer 130 lest items covering mental, motor and infant behaviour. Bayley scales of infant development have been standardized for Indian children upto 30 months of age. In the community setting health workers can be trained to screen development of children by using Baroda Development Screening Tests (BDST), Trivandrum Development Screening Chart (TDSC), and Woodside Screening System (WSST). Draw-a-man test for Indian children is also a simple and a reliable tool of development assessment in pre-school children. Binet-Kamath (Stanford-Binet) and Wechsler intelligence scale for children arc more sophisticated and can be conducted in some selected centers. The developmental quotient can be calculated as follows: DQ = developmental age / chronological age x 100. The quotient can be separately calculated for motor and mental development.
Basic Bed-side Tools for Assessment
The pediatric resident must acquire simple objects and instruments to undertake bed-side assessment of development whenever indicated. These items include torch, dangling red ring of 6.5 cm diameter, red ball of 5.0 cm diameter, ten 2 to 5 cm sized colourful cubes, temple bell, rattle, cup with handle, bunch of keys, pellets or beads, picture book, paper and crayon and percussion hammer.
Indicatio for Developmental Assessment
1. Follow up of high risk neonates for early detection of cerebral palsy and or mental retardation.
2. Complete evaluation of children with developmental, chromosomal and neurological disorders.
3. To differentiate children with retardation in specific fields of development as opposed to those with global retardation.
Accurate history of developmental mile stones is often difficult to obtain due to poor observation and educational status of mother. Early events in the life of child’s development may be forgotten by the parents. The mile stones should be asked in a chronological order in a simple and lucid manner. The social smile must be differentiated from spontaneous smile which even newborn babies may exhibit during sleep or fantasy. It is not enough to know when the child controlled his head or was able to sit. It is equally if not more important to know the quality of head control and whether he could sit without support with a straight back or in a crouched posture. It is important to ask the mother as to how the development of the index child compares with his siblings. She can recollect comparison more readily rather than precise ages for achieving various skills. The mother should be asked whether the child interacts and plays with children of his age or likes the company of younger children. The efforts should be made to identify whether child is globally retarded or backward only in an individual or specific field e.g. delayed speech in a deaf child, delayed walking in a child with congenital dislocation of hips etc. The developmental progress of older children is best evaluated by consideration of school performance, proficiency in games, motor dexterity and social behaviour.
Apart from assessing the developmental milestones, the resident should undertake a detailed neurological examination, evaluate the muscle tone (adductor angle, scarf manouvre, Landau reflex, parachute reaction etc.) and special senses (vision and hearing). All high-risk infants must be subjected to detailed assessment of hearing and vision at the age of 6 months. Factors associated with deafness during infancy include prematurity, meningitis, cranio-facial malformations, hypoxic-ischemic encephalopathy, congenital viral infections, kemicterus, prolonged use of aminoglycosides and furosemide, parental consanguinity and family history of deafness.
The child is placed in different postures and positions depending upon his chronological age and assessed for expected developmental responses as given below. In preterm babies corrected age (conceptional age) should be used as the chronological age especially during first year of life.
The examiner suspends the infant in a prone position by supporting the abdomen of the baby on his palm. The extension of neck and flexion of the extremities is observed.
Newborn – Head hangs completely and back is rounded.
4 weeks – Head momentarily lifted up, elbow flexed.
6 weeks – Head held momentarily in the same plane as rest of the body.
8 weeks – Head maintained in the same plane as rest of the body and momentarily lifted beyond this.
12 weeks – Head maintained well beyond the plane of the rest of the body.
The infant is placed on the examination table in a prone position and watched for position of head, arms, pelvis and legs.
Newborn – Head is kept to one side, pelvis is raised, knees are drawn up under the abdomen.
4-6 weeks – Hips and knees are partially extended, can lift chin off the couchmomentarily.
8 weeks – Head maintained in midline with chin lifted off the couch.
12 weeks – Pelvis is kept flat on couch with legs completely extended, chinis lifted off the couch.
16 weeks – Chest is maintained off the couch, arms are stretched out in full extension.
20 weeks – The body weight is supported on forearms.
24 weeks – Weight is supported on hands, and baby rolls from prone to supine. Indian babies first learn to roll from supine to prone because they are usually not nursed in a prone position.
Supine Posture and Sitting
The infant is placed supine on the couch and pulled to sitting position by lifting at the forearms (traction response).
Newborn – Complete head lag.
4 weeks – Head maintained in plane of the body momentarily when baby is held in a sitting position, back is rounded. Chin may be lifted up momentarily.
12 weeks – Head held up when supported in a sitting position but it tends tobob forwards.
16 weeks – When pulled up, there is slight head lag during the beginning and then head is flexed beyond the plane of the body. When held in sitting position and baby is swayed, the head wobbles.
20 weeks – No head lag, head is stable without wobbling and back is straight.
24 weeks – When about to be pulled up, lifts head off the couch in anticipation. Can sit supported in a pram or high chair.
28 weeks – Can sit on the floor with hands forward for support.
32 weeks – Can sit momentarily on the floor without support. I
36 weeks – Sits steadily without support and can lean forward and recover his balance.
40 weeks – Can sil up from supine position.
48 weeks – Can turn side ways and twist around to pick up an object.
Vertical Suspension, Standing and Walking
Newborn – Walking reflex for 2 to 3 weeks.
8 weeks – Can hold head up more than momentarily.
24 weeks – Puts almost all weight of the body on the legs.
28 weeks – Bounces with pleasure.
36 weeks – Pulls self to stand, can stand with support.
44 weeks – Lifts one foot while standing.
48 weeks – Walks two hands held or on holding the furniture.
1 year – Walks few steps independently.
15 months – Creeps upstairs, can kneel without support.
18 months – Can get up and down the stairs without help, pull a wheeled toy.
2 years – Walks up and down the stairs with two feet on each step, walks backwards on imitation, picks up objects from floor without falling, runs, can kick a ball.
2½ years – Can walk tiptoes, jumps on both feet.
3 years – Goes upstairs with one foot on each step, jumps off the bottom step.
4 years – Comes down stairs with one foot on each step, can skip on one foot.
5 years – Skips on both feet.
Fine Motor, Adaptive and Social Responses (Manipulations)
Newborn – Grasp reflex
4 weeks -Hands mostly closed
8 weeks – Hands kept open more often
12 weeks – Hands mostly open, grasp reflex disappears, plays with a rattle when it is placed in the hand.
16 – to reach objects but overshoots, hands come together during play.
20 weeks – Goes for objects and gets them usually with bidexterous approach, puts objects into mouth, plays with toes.
24 weeks – Drops one object when another is given, holds rattle, picks up a cube with crude palmar grasp.
28 weeks – Unidexterous approach to objects, transfers object from one hand to the other, feeds self with a biscuit, bangs object with each other or on table top, retains one cube when another is offered.
40 weeks – Pincer finger-thumb fine grasp to pick up a pellet.
1 year – Gives toy to examiner, puts one object after another into the basket, mouthing is much reduced.
15 months – Self feeds with a cup, builds tower of 2-3 cubes, holds two cubes in one hand.
18 months – Can self feed with a spoon, makes tower of 3-4 cubes.
2 years – Makes tower of 6-7 cubes, can turn door knob, puts on and takes off socks, shoes and pants.
2½ years – Can hold pencil in hand to scribble lines.
3 years – Makes tower of 9-10 cubes, can dress and undress, can manage buttons, can draw a circle.
Social Mental and Language
4 weeks – Watches mother intently when she speaks to him. Follow a dangling object upto 90°, quietens on sound of bell.
6 weeks – Social smile, follows moving person
8 weeks – Fixes and focusses gaze, eye-to-eye contact, vocalizes.
12 weeks – Hand regard, recognizes mother, can follow an object upto 180°, babbles when spoken to, squeals with pleasure and gets excited on seeing a toy.
16 weeks – Demonstrates excitement when feed is being prepared, laughs loud, turns head towards sound of bell/rattle.
20 weeks – Smiles at mirror image, dry during day time if toilet trained.
24 weeks – No more hand regard, shows displeasure when toy is taken away, demonstrates likes and dislikes, when an object is dropped he looks for it searchingly, dry by night.
28 weeks – Imitates actions and sounds, enjoys “peek-a-boo” and “pat-a-cake” games, responds to name, pats mirror image, says monosyllables like ba, da, ma.
32 weeks – Imitates sounds, responds to ‘no*, produces disyllables like ma-ma, ba-ba, da-da etc.
40 weeks – Pulls clothes of mother to attract attention, waves bye-bye, repeats performance which is laughed at.
1 year – Gives toy to examiner, interested in picture book, shakes head for ‘no’, says 2-3 words with meaning.
1 ½ year – Jargon spcech, indicates the need for pottie and when parts are wet.
2 years – Repeats what is said, uses the words T, ‘me’, ‘you’, lisping and some stuttering is common., can point to 3 parts of a doll.
3 years – Normal speech, attends to toilet needs except for wiping, candress and undress.
The developmental milestones are achieved by healthy normal children within a narrow range of several weeks. The recommended corrected ages (calculated from the expected date of delivery) for undertaking developemental assessement are 4 months, 8 months, 12 months and then every 6 months till 3 years of age. The upper age-limits for achievement of some of the target milestones are given below:
1. Lack of social smile by 2 months.
2. Absence of stable head control by 4 months.
3. Inability to recognize the mother by 6 months.
4. Inability to sit when pulled to sit by 6 months and lack of independent sitting without support by 8 months.
5. Lack of creeping by 9 months.
6. Inability to stand without support by one year.
7. Inability to walk without support by 18 months.
8. Absence of syllabic babbling by the age of one year and failure to make meaningful sentences by 3 years of age.
9. Lack of pincer grasp by the age of one year.
10. Inability to play interactive games by the age of one year.
These children should be subjected to a detailed developmental assessment by an experienced developmental psychologist.
Early Markers of Cerebral Palsy
The high risk newborn babies should be followed up for early identification of neuromotor disability so that appropriate stimulation therapy can be initiated to enhance neuromotor development. Mother can be taught by the therapist to use simple culturally acceptable procedures to provide stimulation to the child. The child should be stimulated by music, bright colored objects, lullabies and interactive overtures of the mother. It must be realized that mother is the best therapist and teacher for her infant. She should caress, touch, tease, talk, sing, tell stories and respond to child’s pranks. The following clinical markers should be looked for to make an early diagnosis of cerebral palsy.
1. Episodes of inconsolable crying, chewing movements, lip smacking, excessive sensitivity to light and noise, spontaneous Moro response etc.
2. Persistent neck tonic posture beyond 4 weeks.
3. Clenched fists with thumbs adducted and flexed across the palm beyond 8 weeks.
4. Paucity or absence of fidgety limb movements during 6-12 weeks.
5. Abnormalities of tone (usually hypertonia but occasionally hypotonia) as assessed by scarf sign and various angles.
6. Persistence of automatic reflexes beyond 4-5 months (Moro reflex, grasp reflex, asymmetric tonic neck reflex).
7. Persistent asymmetry of posture, tone, movements and reflexes is abnormal.
8. Slow head growth.
Gives ages at appearance and disappearance of common developmental reflexes. Absence of parachute response and Landau reflex and persistence of other automatic reflexes beyond the ages mentioned in the table are indicative of cerebral palsy.
|Reflex||Age of appearance||Age of disappearance|
Adductor spread of knee jerk
Persists in normal children
Assessment of Muscle Tone as a Marker of Cerebral Palsy
Alterations in muscle tone especially hypertonia is common in cerebral palsy. Healthy term newborn babies have physiological hypertonia and there is gradual reduction of muscle tone during first year of life. Muscle tone should be assessed when baby is alert, wide awake, not crying and should lie supine with head in the midline. The muscle tone is assessed by (i) looking for abnormal posture of the limb, (ii) palpation of muscles for flabby or firm feel, (iii) range of movements and resistance encountered at major joints and (iv) by shaking the unsupported limb for range and flaility or stiffness of movements.
The range of movements at major joints is tested during infancy as follows:
Adductor angle. Infant lies supine with legs extended and head in the midline. Both the hips are abducted maximally by holding at the knees with index finger resting over the front of thighs. The angle between the thighs is the adductor angle. The adductor angle is narrow and resistance is encountered during the procedure when infant is hypertonic. Asymmetry between the right and left leg should be noted.
Popliteal angle. The infant lies supine on the cot. The hips are flexed completely on to the abdomen by holding at the knees. The legs are then extended by gentle pressure with examiner’s hands placed behind the legs and popliteal angle is measured. The resistance encountered to the manouvre is noted on both sides. The angle is measured separately on two sides.
Dorsiflexion angle of the foot. The fool is passively dorsiflexed by applying gentle pressure with the thumb placed over the sole. Angle between dorsum of foot and front of leg is noted. During infancy dorsiflexion angle at the ankle is 70” or less.
Heel-to-ear manouvre. With the infant lying supine, legs extended at the knees are held together and lifted as far backwards as possible towards the ears without lifting the pelvis from the table. Increased resistance on one side is suggestive of asymmetry of tone on the two sides.
Scarf sign. The muscle tone in the upper limbs is tested by assessing the range of movements at the shoulders. The infant lies supine on the cot. The upper limb, flexed at the elbow, is pulled as far possible across the chest by holding at the hand and wrist. The position of the elbow in relation to midline of the body is noted.
Transitory tone abnormalities (especially hypotonia) may be noted during first six months of life and they normalize by the age of one year.
Parachute response. Hold the child with both hands by the waist and suddenly lower him over a table top. There will be brisk extension and abduction of the upper limbs with extension of fingers as if to break the fall. It is a protective reflex and appears around 8 to 9 months of age. The reflex is absent in infants with spastic type of cerebral palsy.
Landau reflex. The infant is suspended in prone position by supporting the abdomen of the baby on the palm. The infant spontaneously extends the neck, trunk and legs after the age of 10 months. Forcible flexion of neck is associated with flexion of hips and legs. The reflex is absent if there is a disorder of muscle tone especially in floppy infants.
Developmental Screening Charts
Sophisticated developmental testing instruments are time consuming and require the services of a trained developmental psychologist. They are useful for detection of borderline abnormalities as well as for research purposes. There is a need to develop reliable simple developmental charts which can be used by a busy clinician or medical health worker in the community.
Trivandrum Developmental Screening Chart (TDSC)
It is suitable for developmental screening of children below 2 years by a paramedical health worker. The range of each test item has been taken from the norms obtained on the Bayley scales of infant development. It is based on 17 simple test items carefully chosen from among 67 motor items of Bayley scales of infant development (Baroda norms). The left hand side of each horizontal dark line represents age at which 3 percent of children passed the item and the right edge represents the age at which 97 percent of the children passed the item in studies conducted at Trivandrum. A plastic ruler or a pencil is kept vertically at the level of chronological age of the child being tested. If the child fails to pass any item that lies to the left side of the age-marker, the child is considered to have developmental delay. It is simple to use and takes 5 to 7 minutes to administer. It is best suited to use in infants around one year of age because most of the test items are concentrated around that age period.
Baroda Development Screening Test (BDST)
To simplify the Bayley scales of infant development, 22 motor items and 31 mental items, not requiring any standardized equipment have been retained. These items were grouped age-wise, one monthly in the first 12 months and 3- monthly thereafter till 30 months. The 50 percent and 97 percent age placement of each item has been plotted on a graph and joined to have two smooth curves. The total number of the items passed by a child is plotted against his chronological age (or corrected age if preterm). When this point falls below 97 percentile curve, the child is considered to have developmental delay and is subjected to detailed assessment.
Interpretation of Developmental Findings
1. The global developmental delay in all the spheres (motor, adaptive, social, language etc.) is suggestive of mental retardation.
2. Isolated delay in gross motor development may occur due to poor physical growth due to protein-energy malnutrition.
3. Lack of environmental stimulation and poor interaction by parents may adversely affect neuromotor development
4. Delay in an isolated sphere of motor development like walking may be due to congenital dislocation of hips.
5. Isolated delay in the development of speech is most commonly due to deafness.
6. Autistic children must be differentiated from children with mental retardation. Autistic children may have normal development upto certain age and then regress especially in their social and communication skills. The autistic children do not like to be held or cuddled and they have no or brief eye contact. They lack emotional warmth and social interaction. They may have stereotyped, compulsive and repetititive movements like rocking, bouncing, head banging, swinging, spinning objects and flapping or twisting their hands. They are lost and engrossed in their own world. The child may be fascinated by visual stimuli like moving lights and fans. Other abnormal behaviours include toe walking, sniffing, licking or smelling objects. Speech may be absent or they may have a gibberish and repetitive (echolalia) language of their own. They may have intense liking or possessive behaviour regarding some inanimate object and violently react to any change in their environment and daily routines. Some children may have a severe sleep problem. The childhood autism rating scale and autism behaviour checklist are useful assessment tools. Patients with fragile X syndrome, congenital rubella syndrome, tuberous sclerosis and Rett syndrome may have some autistic mannerisms.
7. Children with attention deficit hyperactivity disorder (ADHD) may have learning disability and school problems.due to hyperactivity and poor attention span. The developmental mile stones are usually normal and some children may have exceptional congnitive abilities. They are unable to sit still and are perpetually “on the go”. They are constantly on the move, fidget, squirm, aimlessly touch and poke their fingers into everything. They are unable to sit through a television program or listen to a story. They have short attention span with poor school performance. They have an impulsive behaviour, blurting out answers before completion of questions and have trouble waiting for their turn. Their behaviour becomes worse in crowded places and infront of guests. They demonstrate temper tantrums and crying episodes on minor pretexts. They are aggressive in their behaviour and uncooperative with their classmates and have difficulty in cultivating friendship. They may have antisocial behaviour like disobediency, defiance, lack of discipline, destructiveness, fire setting and inflicting harm to others. They have associated language and learning disability due to distractibility and short attention span. The diagnosis is facilitated by using Connors questionnaires which are comprised of 28- items for teacher and .48- items for parents for objectivised evaluation of children with ADHD.