Differential diagnosis of speech and language delay

Mental retardation
This is usually associated with global language delay. Causes of mental retardation include;  genetic defects, intrauterine infection, placental insufficiency, maternal medication, trauma to the central nervous system, hypoxia, maternal  hypothyroidism, meningitis or encephalitis, and metabolic disorders

Hearing loss
This can be conductive or sensorineural hearing loss. There may be an associated history of kernicterus or severe jaundice, neonatal hypoxia, bacterial meningitis, intracranial haemorrhage. It is associated with Pendred syndrome, Waardenburgs syndrome, Ushers syndrome

Cerebral palsy
Speech delay is very common in children with cerebral palsy

Autism
This is characterised by delayed language development, with speech abnormalities like echolalia, failure to develop the ability to relate to others and ritualistic and compulsive behaviour, including stereotype repetitive behaviour.

Bilingualism
Bilingualism is known to result in temporary expressive language delay. The child usually develops both languages by the age of 5 years

Maturation delay
Delay in the maturation of central neurological processes necessary for talking. This is more common in boys and there is usually a family history. The prognosis is excellent

Psychosocial deprivation
There is an increased incidence of speech delay in abused children

Expressive language disorder (developmental expressive aphasia)
This children have a normal development in all other areas but unable to translate ideas into speech due to a primary brain dysfunction.

Elective mutism
These children do not speak because they do not want to. They may require referral to a child psychiatrist. They may also have associated speech delay.

Receptive aphasia
There is a deficit in the comprehension of spoken language. They show normal response to non verbal auditory stimuli. They gradually acquire a language of their own usually understood by their family.