Yes, to a large extent. Let us first know what DD is?

DD:DQ <65-75% at risk of DD. When a child can't perform an item (gross motor, coordination and fine motor, personal social and language), which 90% of children of children of his age can perform, he is suffering from DD.

MR:A generic name for intellectual disorders of variable causes-criteria being:

• Low intelligence (IQ <70) clinically judged in case of infants
• Impaired adaptive and social functioning.
• Onset before maturity i.e. <18 years.

CP: A disorder of mainly of movement and posture due to non-progressive injury to developing brain up to the age of 5 years.

A child with MR and CP has developmental delay.

Prevalence: 3% in the general population (2.5% in USA), 1% in school children.

Sex: Commoner in boys than in girls – 2:1 (mild DD), 1.5:1 (severe DD), may be due to X linked disorders like Fragile X syndrome.

Classification of MR IQ (MA/Cax100) based on intelligence tests in auditory memory, visual-spatial capability and receptive and expressive language.

Normal: IQ 90-110, Borderline: IQ 70-90, low achiever, independent life, psychosocial.

Criteria	Mild	Moderate	Severe	Profound
IQ	51-70	26-50	21-35	< 20
Prevalence	85%	5-10%	5	10
Major  grading	Educable	Trainable	Unable to manage self	Unable to guard
Social  Functions	Well adjusted repetitive work independent	Well adjusted Special training Semi Dependent	Simple conversation Minimal self care	Minimal language very min. self care Total supervision

International classification of DD: based on etiology.

• SDD (Severe type): DQ<50, 0.3-0.2% of population. Mainly biological causes affecting embryogenesis or severe early brain insult like.
• Genetic: Down syndrome, inborn errors of metabolism-phenylketonuria, galactosemia
• Prematurity: <1500 gm (5-10%), <1000 gm (20%).
• Birth asphyxia, Prenatal/neonatal infections, Cretinism.
• CNS malformations : Schizencephaly, Migration defects.
• Severe and profound DD may have blindness, deafness, seizure, motor disabilities.
• MDD (mild type) : DQ 50-70, 85%, difficult to diagnose than SDD.

Diagnosis:

• History:
  Gestational history, timing and mode of delivery, first cry, birth weight, birth asphyxia, birth trauma, pathological jaundice, After birth stay in hospital.
  Age at detection, co-existing medical problems like seizure disorders, sleep and behavioral problems, previous rehabilitation services, investigations and laboratory tests, school performance, family history, consanguinity, h/o substance use etc. in mother, father
• Physical examination:
  Dysmorphism, head circumference shape of head, fontanels and sutures, spine abnormalities, Face, Eyes, Ears, Cutaneous markers, Other anomalies, Cranial nerves, tone (hypo/hyper), Strength (paucity of movements), Deep tendon reflexes (exaggerated), Cerebellar signs, Abnormal or persistent neonatal reflexes Moro, ATNR (atypical tonic neck reflex), Postural responses (neck tightening).

Parameters	Dd, if not achieved	Normal Range
Response to voice	4 th mo	1-3 mo
Smiles at others  (social)	6 th mo	2 mo (1-4 mo)
Holds head steady	6 th mo	4 mo (2-6 mo)
Sits alone steady	12 th mo	8 mo (5-10 mo)
Stands alone steady	18 th mo	1 year (9-14 mo)
Walks well	20 th mo	10-20 mo
Talk in 2-3 words	3 rd yea	10-30 mo
Talk in 2-3 words	3 rd yea	10-30 mo
Tells name / eats, drink self	4 th year	2-3 years
Toilet control	4 th year	3-4 years

Common presentations:
First few mo : dysmorphism, poor suckling, feeding difficulties, extremely irritable or lethargic, floppy or spastic, asymmetry of movements, lack of visual or auditory response, no social smile, poor head control.
Infancy : Persistent fisting beyond 3mo, no sitting, standing, hand preference before 12 mo Toddlers (2-3 years): delayed speech, Preschool: language problem, delay in fine motor skills like cutting, coloring, drawing, behavior problems, School going (> 5 years): poor learning, behavior problems like in attention, anxiety, mood changes.

Commonly used Tests:
Developmental tests:

• DDST: Assessment of 4 areas of development up to 6 years in 10-25 m.
• Gessel development schedule: Dx and evaluation rather than milestones up to 5 years.
• BSID (Baley scale for infant development): 1 month to 3½ years to assess language, visual problem-solving skills, behavior, fine and gross motor skills.
• Baroda development screening test: BSD based standardized on Indian children.
• Trivandrum development screening chart: based on 17 selected items of BISD Baroda norms up to 24 mo in 5-7 m.
• Development screening test: up to 15 years, standardized on Indian children. These development tests do not predict future IQ and have limitations.

Intelligence tests in children:

• WPPSI-R (Wechsler Preschool and Primary scale of intelligence-revised): for 3-7 years.
• WISC-III (Wechsler intelligence screening chart): mental age> 6 years.

Tests for adapting functions:

• VABS (Vineland adaptive behavior scale)
• ABS: Stability of adaptive skills through adulthood in Prader-Willi syndrome, increasing adaptive defects in Fragile X-syndrome

Investigations:

• Urine Metabolic Screening
  
• Urinary amino acids
  
• Blood: VMA, ammonia, lactate, lead, copper, uric acid, ca, phosphate, very long chain fatty acids, alkaline phosphatase, CPK, serum T3 T4 & TSH.
• Serology: TORCH, AIDS, Chicken pox, Syphilis.
• Radio imaging: Bone age, x-ray skull: craniosynostosis, calcifications. CT, MRI: gross malformation of brain, infarct/hemorrhage, PVL, porencephaly, mass, tumors, nodule, hydrocephalus
• Neuro electro physiological tests: EEG, EMG, NCV visual and auditory EP.
• ENZYMEASSAYS
• T/t ANDEM MASS SPECTROMETRY (TMS) on blood filter paper spots.
• Cytogenetic studies: Chromosomal analysis-Karyotyping if abnormal genitals. History of exposure to teratogens, Down syndrome, Fragile X syndrome.
• Specific mitochondrial tests in selected cases.

Prevention : Although DD can't be treated but it can be prevented to a large extent.

Primary prevention : Measures before, during and after delivery, and infancy and childhood that can stop the occurrence of DD.

• Early prenatal care and use of folic acid to prevent neural tube defects.
• Prenatal diagnosis of chromosomal and genetic diseases, biochemical diseases and given advice-choice of reproduction left to the family.
• Immunization program: MMR to all children at 15-18 mo, Rubella vaccine to all girls and especially before marriage and at least 3 mo before conception, varicella, JB, Meningococcal and Hib vaccines.
• Avoid consanguineous marriage to prevent AR metabolic disorders.
• No marriage of adolescent girls <18 years and family education to adolescents to prevent adolescent pregnancy and transmission of STDs and HIV.
• No pregnancy>35 years to prevent Down syndrome.
• No use of alcohol, smoking, drugs or substance especially during pregnancy.
• Better antenatal and obstetric care: At least 3 antenatal checkups, Nutritional support, Avoidance of teratogenic drugs, hormones, iodides, anti-thyroid drugs, irradiation and contact with viral infections during pregnancy.
• Safe delivery and neonatal care: Prevention and management of birth injuries, asphyxia, hypoglycemia, hypothermia, hyperbilirubinemia and sepsis.
• Accident prevention: (a) Railing and guards on roofs to prevent falls and other accidents in the home, (b) Appropriate seat restraints during driving and helmets during biking and skate boarding.
• Improving psycho social and cultural factors: Marriage age, stability of marriage, limiting the number of children, compulsory education especially to ten girls, improving poverty, public awareness, community progress etc.

Secondary prevention:

• Pre-symptomatic detection: (a) Newborn screening for inborn errors of metabolism, hypothyroidism, (b) Newborn hearing screening, (c) Pre-school lead poisoning prevention
• Early diagnosis and prompt treatment of CNS infection, cretinism, neonatal hyperbilirubinemia, galactosemia, PKU, Homocystinuria to prevent brain damage
  
  

Bihar Pedicon 2006 - Conference Abstracts.Pediatric Oncall [serial online] 2006 [cited 15 September 2006(Supplement 9)];3. Available from:
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BIHAR_PEDICON/developmental_delay.asp