developmental delay

The developmental delay - A term used if a baby or young child has not acquired new skills within the expected time range. Normally, new abilities and new patterns of behaviour appear at given ages, and existing behaviour patterns change and sometimes disappear (see child development). Delays vary in severity, and may affect the development of one or more of the following skills: hand–eye coordination, walking, listening, language, speech, or social interaction.

GENERALIZED DELAY
A child who is late in most aspects of development usually has a generalized problem. This may be due to a severe visual or hearing impairment, limited intellectual abilities (see learning difficulties), or damage to the brain before, during, or after birth. For further information on possible causes of generalized delay, see the table above.

SPECIFIC FORMS OF DELAY
Delay in movement and walking often has no serious cause. In some cases, however, there are specific causes; these can include muscular dystrophy and spina bifida.

Delay in developing manipulative skills (the ability to pick up and use objects with the hands) is often due to lack of adequate stimulation. Delayed speech development may have various causes. The most important is deafness, which may cause the child to be unresponsive to sound.

Autism is a rare cause; in this condition, hearing is normal but the child may be unresponsive to the human voice. Another possible cause is generalized difficulty with muscle control, which may affect speech production; this may occur in children who have cerebral palsy. Damage to, or structural defects of, the speech muscles, the larynx (voicebox), or the mouth may also cause speech difficulties, as may any disorder that affects the speech area of the brain (see aphasia; dysarthria; dysphonia; speech disorders).

Children vary enormously in the age at which they gain control of bladder and bowel function. Usually, bowel control is acquired first. Delay in bladder control is much more common than delay in bowel control. Such delays have many possible causes (see enuresis; encopresis; soiling).

ASSESSMENT
Delays may first be noticed by parents; if this is the case, a health visitor or doctor should be consulted promptly. Delays may also be detected during routine developmental checks with a health visitor, family doctor, or paediatrician. These checks are performed at various ages, but usually at birth, six weeks, six to eight months, 18 to 24 months, three years, and five years.

A child who shows signs of developmental delay should undergo a full assessment. This will usually include a physical examination, along with hearing tests, vision tests, and a thorough developmental assessment. The child may need to undergo further investigations, such as blood tests, to check for any genetic abnormality, or referral to a specialist such as a neurologist, speech therapist, or physiotherapist.

TREATMENT
The treatment depends on the severity and probable cause of the delay. It may include a course of speech therapy or family therapy, or provision of physical aids such as glasses or a hearing aid. Parents are often of prime importance in providing help for their child. In some cases, however, the child may also benefit
from being admitted to a school or special unit that provides education for children with specific difficulties.

CAUSES OF DEVELOPMENTAL DELAY
• Physical or emotional deprivation (child abuse). Lack of affection, stimulation, or teaching.
• Severe visual impairment. Vision is vital for normal development in all areas. Children learn to recognize objects before learning their names, they learn about sounds by seeing which objects make which sounds, and they become motivated to crawl and walk by the desire to explore their surroundings (see vision, disorders of; blindness).
• Severe hearing impairment (see deafness).
• Learning difficulties.
• Damage to the brain before, during, or after birth, or in infancy. The results of damage depend on which parts of the brain are damaged and on severity (see brain damage; cerebral palsy).
• Severe, prolonged disease of any organ or body system (such as bone, heart, kidney, muscle, and nutritional disorders).