Developmental delay

Before looking at developmental delay, you need to understand normal development. In normal development, there are four areas which leads to four areas of potential delay. Specific delay or one of these four areas (fine and gross motor delay tends not to present separately) and global delay where all four areas are delayed. This page contains some key concepts which you may not be familiar with so have a look at this page.

In the same sort of area, there's also things like assessing hearing and vision. Learning disability is another condition which can present with developmental delay.

Global developmental delay

This is a delay of all areas of development and usually presents in the first two years of life. There is a wide variety of causes but essentially, anything which can affect the development of the brain in the antenatal, perinatal or postnatal periods. This can include genetic problems, infections, neurological syndromes - basically it's a really long list of things that affect the brain early in life. If it affects your brain early in life, you can probably get global developmental delay.

Abnormal motor development

Essentially, if the child is not reaching the normal milestones purely in the motor area or not having normal variants (e.g. bottom-shuffling instead of crawling). Children acquire a large proportion of their motor skills between 6 months and 2 years which is hence when abnormal motor development usually presents.

The most important disease to exclude is cerebral palsy but there are other causes of abnormal motor development. Spinal cord lesion, the most common of which is spina bifida can present in this way and some congenital muscle disorders. In 25% of cases, however, no cause is found.

Hand dominance shouldn't become apparent until 1-2 years or later. If there is an asymmetry before this type it could be a sign of a hemiplegia.

Abnormal speech and language development

If you've checked out the key concepts page, you'll know that disorder and delay are two different things. Although it might not be obvious whether the problem is just a delay rather than a full-blown disorder.

Delay

Hearing loss is often picked up through speech delay. If you can't hear, you can't easily learn to speak. It can part of a the spectrum of symptoms in global developmental delay. Difficulty in speech production due to disease or anatomical deficit can cause delay (e.g. cleft palate or cerebral palsy). If the child is in an environment with a lack social interaction then its never going to learn to speak. Finally, it can just be a normal variant.

Disorders

Disorders of speech are thought of in the same way as they are in stroke. Obviously, the cause is different as children tend not to get cerebrovascular disease. Anyway, you get disorders of:

• Comprehension (receptive dysphasia) - difficulty understanding speech
• Expression (expressive dysphasia) - difficulty to say things even if you know what you want to say
• Phonation - problems such as dysfluency (stammering), dysarthria or verbal dyspraxia
• Semantics - basically, construction of sentences
• Social skill - which is basically the bit below.

Abnormal social development

See autism to get a better idea of what this is. Autistic spectrum disorders covers a wide range of disorders.