Developmental delay: A clue to developmental
disorders
by Joel D. Lazaro
Developmental delay is a common problem of children with an estimated prevalence
as high as 10% (Batshaw, 1993). Despite its common occurrence, cues to developmental
delay remains to be difficult and challenging for most doctors. It is known that
early identification of developmental delay leads to early intervention that promotes
good outcome reducing the chances of long- term disability in the child. It is the
objective of this article to determine the approach for identifying developmental
delay in infants and young children and discuss the approach in the management of
a child with developmental delay.
What is the definition of a developmental delay?
Delay is said to exist when a child does not reach developmental milestones at the
expected age. This may seem to be a simple definition but in actual clinical practice
may be a complicated process to determine. The reasons behind this are as follows:
First, there is a wide variation as to what constitute 'normal'. Indeed, normality
is infinitely more variable than abnormality and allowance has to be given to cover
a broad variation in children's abilities. Second, children's developmental skills
are continuously evolving making it difficult to decide if the delay is something
permanent or transient in nature. A common pitfall committed even by doctors is
to say that 'the child will outgrow' the delays even before an extensive evaluation
has been made. Finally, development is a transactional process with many forces
and influences in the child's environment affecting its course throughout life making
it difficult to make definitive prognosis regarding future outcomes.
What are the signs to watch out for?
The early identification of developmental disabilities in children rests on the
hands of parents and physicians who are attuned to the developmental progress of
children. The first order of the day is to be familiar and knowledgeable about the
normal progress of development in children. This should be followed by learning
the 'red flags' or danger signals of developmental delay in various areas of developmental
function as enumerated in Tables 1-4 (Palfrey, 1994). The 'red flags' serve as a
guide for healthy professionals on when to recommend for a more extensive neurodevelopmental
evaluation
Table 1 Gross Motor: Red flags
4.5 months Does not pull up to sit
5 months Does not roll over
7-8 months Does not sit without support
9-10 months Does not stand while holding on
18 months Not walking
2 years old Not climbing up and downstairs
2.5 years old Not jumping with both feet
3 years old Unable to stand on one foot momentarily
Table 2 Fine Motor: Red flags
3.5 months Persistence of grasp reflex
4-5 months Unable to hold rattle
7 months Unable to transfer objects from one hand
to another
10-11 months Absent pincer grasp
15 months Unable to release objects from hand
2 years old Unable to scribble
Table 3 Language: Red flags
6 months Does not turn eyes/head to sound
10 months Not babbling
15 months Does not respond to 'no' , 'bye-bye'
18 months Does not have meaningful words beyond
mama/papa
2 years old No two word phrases
3 years old No simple sentences
Table 4 Psychosocial: Red flags
3 months Not smiling socially
6-7 months Not laughing in playful situation
8-9 months No interest in peek-a-boo
12 months Does not search for hidden objects
15-18 months No interest in cause and effect games
2 years old Does not engage or interact with other kids
How is developmental delay diagnosed?
The child with developmental delay requires an extensive diagnostic evaluation which
aims to: (1) describe the child's current healthy status; (2) describe the child's
current functional status, including developmental abilities and disabilities; (3)
identify the etiologic cause of the condition; and (4) describe the child's socio-environmental
condition (Lepta, 1998).
Clinical History
The physician must perform a systematic history taking with emphasis on identifying
established biologic and environmental risk factors implicated in cases of developmental
delay (table 5).
Table 5 Risk Factors for Developmental Delay
Biologic:
Prenatal Maternal Factors Substance abuse (drug/alcohol)
Chronic illness (diabetes)
Previous stillbirths or miscarriage
Perinatal factors Prematurity
Low birth weight
Obstetrical problems (toxemia, bleeding)
Neonatal factors Sepsis, meningitis
Seizures
Bleeding
Hypoxia
Jaundice
Postnatal factors Exposure to lead, other toxins
Seizures
Meningitis/Encephalitis
Growth retardation
Socio-environmental Factors
Child abuse/neglect
Poverty
Stressful life events (death, divorce)
Single, teenage parent
The family history may also be helpful because many developmental disorders are
genetically based and are passed on from one generation to another. The developmental
history is also extremely important as this will chronicle the acquisition of developmental
skills at a particular age over a period of time. If accurately gathered, the information
will help the health professional in determining whether the developmental delay
is inborn or acquired. It should also help distinguish whether there was delayed
acquisition of skills or loss/regression of skills.
What are the physical tests to perform?
Abnormalities on physical examination may serve as an indirect indicator of the
presence of developmental delay. It may also provide a clue to the etiologic cause
of the delay. Anthropometric measurements such as height, weight and head circumference
are vital in the assessment as many children developmental delay have co-existing
abnormalities in growth patterns. The presence of congenital anomalies or dysomorphic
features are also important markers as many genetic syndromes have co-existing developmental
disabilities. Functional assessment of sensory functions e.g. hearing and vision
must also be included. Finally, a developmentally oriented neurologic examination
is vital to the diagnostic process of a child with developmental delay.
What is developmental evaluation?
Standardized evaluation of development is indicated in the comprehensive evaluation
of a child who has developmental delay. These may include tests of general intelligence,
language, fine motor skills, gross motor skills and social adaptation. The selection
of test should relate to the child's condition and should provide a profile of the
child's strengths and weaknesses, not just a series of scores. The tests to be valid
must also be administered by competent and trained professionals. The results of
developmental evaluation will help the health professionals in formulating a developmental
diagnosis. Table 6 shows the different patterns of developmental delay exhibited
by selected developmental disorders. The results can also serve as baseline for
subsequent monitoring of the child's progress especially after intervention or treatment.
Table 6 Pattens of Developmental Delay
Developmental disorder Gross Motor Fine Motor Language Social Adaptive
Cerebral Palsy D N/D N/D N/D
Mental Retardation N/D D D D
Autism N N/D D D
Communication N N D N/D
Legend:
N: Normal
D: Delayed
Are the laboratory tests?
There are no standard or routine laboratory studies indicated for a child with developmental
delay. The decision to choose a particular diagnostic test will depend on the etiologic
cause being implicated as a cause of developmental delay. The test selections are
varied and wide-ranging which includes genetic studies, imaging studies, metabolic
studies, and electrophysiologic tests (EGG, BAER).
MANAGEMENT OF A CHILD WITH DEVELOPMENTAL DELAY
Regardless of the specific nature of the child's developmental delay, there is unanimous
opinion from different sectors (e.g. medical, educational, etc) that early identification
of developmental delays leads to early intervention and better outcome for the child.
There is sufficient evidence in medical research that the best chance for effecting
developmental change is while the nervous system of the very young child is still
malleable and responsive (Palfrey, 1994). This concept is called i®neuroplasticity'.
Management of a child with developmental delay needs a multidisciplinary approach
involving many disciplines providing a variety of effective educational and therapeutic
interventions depending on the specific nature and/or etiologic cause of developmental
delay. Aside from those mentioned, additional treatment includes (1) health maintenance,
(2) treatment of underlying cause (if possible), (3) treatment of associated conditions,
(4) relief of symptoms, (5) anticipatory guidance to prevent secondary complications
and (6) environmental support (Lipak, 1996). The prognosis of a child with developmental
delay varies widely according to the type and severity of the underlying disorder.
REFERENCES
Batshaw, M. 1993 Mental Retardation. Pediatrics Clinics of North America Vol. 40:507-521
Palfrey, J. 1994 The Infant or Young Child with Developmental Delay The New England
Journal of Medicine. Vol. 330 No. 7:478-483
Liptak, G. 1996 The Pediatrician's Role in caring for the Developmentally Disabled
child. Pediatrics in Review. Vol. 17 No. 6:203-210
Liptak, G. 1998 The Child who Has Severe Neurologic Impairment Pediatric Clinics
of North America . Vol. 45 No. 1: 123-144