Intellectual disability: New name for an old problem???

It is never easy for any one to deal with a child with mental retardation. It is hard for the child no doubt, but equally hard for the parent to come to terms with the fact, and harder still for the dentist to approach the subject with the parent. 

A blunt " Is your child normal?" is not only insulting to the parent and child alike but also; given the broad range of the term "normal" thoroughly unprofessional. 

One of the ways in which the profession has tried to circumvent this problem has been to come up with newer and more "socially correct" terms. But does this really help us understand the condition or does it simply complicate matters by presenting us with a confusing array of terms which mean little to most? In this series of posts DCSN takes a look at our understanding of intelligence, intellect and the various conditions which manifest with intellectual disability.

Definition

The evolution of the term

Intelligence and measuring intelligence

Conditions which manifest with intellectual disabilty

What is Intellectual disability?

Intellectual disability is a disability characterized by significant limitations both in intellectual functioning and in adaptive behavior as expressed in conceptual, social, and practical adaptive skills. This disability originates before the age of 18.

The term intellectual disability covers the same population of individuals who were diagnosed previously with mental retardation in number, kind, level, type, and duration of the disability and the need of people with this disability for individualized services and supports. Furthermore, every individual who is or was eligible for a diagnosis of mental retardation is eligible for a diagnosis of intellectual disability.

What causes intellectual disability?

Intellectual Disability or mental retardation is an umbrella term which is seen in a wide variety of conditions. Strictly speaking the clinician should treat intellectual disability as clinical sign suggestive of an underlying pathology rather than as a disease in itself. Given below is a list of conditions that can lead to intellectual disability

Causes of intellectual disability

(from Bherman Et al (ed) Nelson's Textbook of Pediatrics)

Category	Type	Examples
Prenatal (causes before birth)	Chromosomal disorders	Downs syndrome*, Fragile X syndrome, Prader Wili syndrome, Klinefelters syndrome
	Single gene disorders	Inborn errors of metabolism, such asgalactosemia*, phenylketonuria*,mucopolysaccaridoses Hypothyroidism*, Tay- Sachs disease        Neuro-cutaneous syndromes such as tuberous     sclerosis, andneurofibromatosis Brain malformations such as geneticmicrocephaly, hydrocephalus and  myelo-meningocele* Other dysmorphic syndromes, such as Laurence  Moon Biedl syndrome
	Other conditions of genetic origin	Rubistein Tabi syndrome De Lange syndrome
	Adverse material / environmental influences	Deficiencies* , such as iodine deficiency and folic acid deficiency Severe malnutrition* in pregnancy Using substances * such as alcohol (maternal alcohol syndrome), nicotine, and cocaine during early pregnancy Exposure* to other harmful chemicals such as  pollutants, heavy metals,abortifacients, and harmful medications such as thalidomide,phenytoin and warfarin sodium in early pregnancy Maternal infections such as rubella*,syphillis*,    toxoplasmosis,cytomegalovirus and HIV       Others such as excessive exposure to radiation*, and Rh incompatibility*
Perinatal  (around the time of birth)	Third trimester ( late pregnancy)	Complications of pregnancy* Diseases* in mother such as heart and kidney  disease and diabetes Placental dysfunction
	Labour (during delivery)	Severe prematurity, very low birth weight, birth  asphyxia Difficult and/or complicated delivery*  Birth trauma*
	Neonatal (first four weeks of life)	Septicemia, severe jaundice*, hypoglycemia
Postnatal  (in infancy and childhood)		Brain infections such as tuberculosis, Japanese  encephalitis, and bacterial meningitis Head injury* Chronic lead exposure* Severe and prolonged malnutrition* Gross understimulation*

Does Autism mean Mental Retardation?

Not all Children with autism are mentally retarded however, it is said that between 75% and 90% of all autistics are mentally retarded. To be diagnosed with mental retardation, one must generally show significant impairment in adaptive living skills and have an IQ under 70 as measured by a standardized IQ test. At the same time, advertisements by certain autism awareness sites proclaim that geniuses such as Albert Einstein, Isaac Newton and Thomas Edison may have had forms of Autism. In order to understand this seeming paradox and to help both parents and dentists keep realistic expectations from an autistic child it is important for us to understand the term "Autistic Spectrum" and the disorders classified under it.

At the same time that Leo Kanner described autism in American children, a German scientist, Dr. Hans Asperger, described a milder form of the disorder that became known as Asperger syndrome. Thus these two disorders were described and are today listed in the Diagnostic and Statistical Manual of Mental Disorders DSM-IV-TR (fourth edition, text revision) as two of the five pervasive developmental disorders (PDD), more often referred to today as autism spectrum disorders (ASD). All these disorders are characterized by varying degrees of impairment in communication skills, social interactions, and restricted, repetitive and stereotyped patterns of behavior.  

Disorders such as Aspergers syndrome may result in individuals who, in spite of their social awkwardness, may have an extraordinary intelligence in other fields such as numbers. However the sad truth is that most children diagnosed with childhood autism will have some form of mental impairment. This is even more so in India where the cases with milder forms of autism often go undiagnosed.

Irrespective of their IQ, patients with autism will have some difficulty in communication and therefore it is imperative that both the dentist and parent prepare themselves for a dental visit

See Also

Preparing your Child for a Dental Visit

Preparing to treat an autistic child

For a detailed description of childhood autism you can download the following booklet, put forward by the national institute of mental health.

Click Here