This document summarizes intellectual disability and related neurodevelopmental disorders. It defines intellectual disability as significantly subaverage intellectual functioning and deficits in adaptive functioning that onset before age 18. The document outlines diagnostic criteria from the DSM-5 and ICD-11 and describes features of mild, moderate, severe and profound intellectual disability. It lists causes, elements of clinical evaluation, treatment considerations and prevalence statistics. The document also summarizes common communication disorders like language disorder, speech sound disorder, childhood-onset fluency disorder, social communication disorder and aphasia. Related conditions involving sensory impairments, learning disabilities and speech disorders are briefly outlined.

1. Neurodevel
opmental
Disorder

2. Intellectual Disability
A group of disorders that have in
common deficits of adaptive and
intellectual function and an age of
onset before maturity is reached.
Also known as Mental retardation

3. DSM-5
Significantly sub average intellectual functioning an
intelligence quotient (IQ) of approximately 70 or
below
Concurrent deficits or impairments in adaptive
functioning in at least 2 of the following areas :
communication, self-care, home living,
social/interpersonal skills, use of community
resources, self-direction, functional academic skills,
work, leisure, health, and safety
Onset before age 18 years

4. Unspecified Intellectual Disability
Diagnosed in individuals over 5 when assessment of the
degree of intellectual disability by means of locally available
procedures is difficult or impossible because of:
• Associated sensory or physical impairments, as in blindness
or prelingual deafness; locomotor disability ; or
• Presence of severe problem behaviors or co-occurring mental
disorder.
• Should only be used in exceptional circumstances and
requires reassessment after a period of time.

5. Prevalence
Intellectual disability has overall general population
prevalence of approximately 1%, and prevalence rates
vary by age
Prevalence for severe intellectual disability is
approximately 6 per 1,000
Male are more likely then females to be diagnosed
with both mild MR (average male: female ratio 1.6:1)
and severe MR (average male: female ratio 1.2:1)

7. ICD-11 Diagnostic Criteria for Mental
Retardation
class Degree IQ
F70 Mild mental retardation 50-69
F71 Moderate mental retardation 35-49
F72 Severe mental retardation 20-34
F73 Profound mental retardation <20
F78 Other mental retardation sensory, physical, behavioral
impairments preclude standardized IQ testing
F79 Unspecified mental retardation

8. Features of mild, moderate, severe and
profound Intellectual Disability
Mild Moderate Severe/ Profound
IQ range 50-69 35-49 <35
% of cases 85% 10% 5%
Ability to self care Independent Need some help Limited
Language Reasonable Limited Basic or none
Reading and writing Reasonable Basic Minimal or none
Ability to work Semiskilled Unskilled, supervised Supervised basic task
Social skill Normal Moderate Few
Physical problems Rare Sometime Common
Aetiology discovered Sometimes Often Usually
Academic skill 6th grade or higher 2nd to 3rd grade

9. Causes of Intellectual Disability
Prenatal 4-28%
Natal 2-10%
Postnatal 3-12%
Unknown 30-50%

13. Elements of Clinical Evaluation of Patient
With Intellectual Disability
Clinical history
Family pedigree (three generation)
Psychiatric Interview
Physical examination
Neurological examination
Laboratory examination
Neuroimaging
Psychological assessment

14. Treatment
Biological, psychological, social, and developmental
dimensions should all be considered when designing a
treatment plan an individual with intellectual
disability.
Treatment plan includes attention to
• Psychoeducational,
• Psychotherapeutic, and
• Psychopharmacologic interventions.

15. Communication Disorders
A communication disorder is any disorder that
affects an individual's ability to comprehend, detect, or
apply language and speech to engage in discourse
effectively with others. The delays and disorders can
range from simple sound substitution to the inability to
understand or use one's native language.

16. Diagnoses DSM-5
The DSM-5 diagnoses for communication disorders completely rework the ones
stated above. The diagnoses are made more general in order to capture the various
aspects of communications disorders in a way that emphasizes their childhood onset
and differentiate these communications disorders from those associated with other
disorders (i.e., autism spectrum disorders).
Language disorder
The important characteristics of a language disorder are difficulties in learning and
using language, which is caused by problems with vocabulary, with grammar, and
with putting sentences together in a proper manner. Problems can both be receptive
(understanding language) and expressive (producing language).
Speech sound disorder
Previously called phonological disorder, for those with problems with pronunciation
and articulation of their native language.

17. Childhood-Onset Fluency Disorder (Stuttering)
Standard fluency and rhythm of speech is interrupted, often causing the
repetition of whole words and syllables. May also include the prolongation of
words and syllables; pauses within a word; and/or the avoidance of
pronouncing difficult words and replacing them with easier words that the
individual is better able to pronounce. This disorder causes many
communication problems for the individual and may interfere with social
communication and performance in work and/or school settings where
communication is essential.
Social (pragmatic) communication disorder
This diagnosis described difficulties in the social uses of verbal and nonverbal
communication in naturalistic contexts, which affects the development of
social relationships and discourse comprehension. The difference between this
diagnosis and autism spectrum disorder is that in the latter there is also a
restricted or repetitive pattern of behavior.
Unspecified communication disorder
For those who have symptoms of a communication disorder but who do not
meet all criteria, and whose symptoms cause distress or impairment.

18. Examples
Examples of disorders that may include or create challenges in language and
communication and/or may co-occur with the above disorders:
autism spectrum disorder - autistic disorder (also called "classic"
autism), pervasive developmental disorder, and Asperger syndrome –
developmental disorders that affect the brain's normal development of social and
communication skills.
expressive language disorder – affects speaking and understanding where there is
no delay in non-verbal intelligence.
mixed receptive-expressive language disorder – affects speaking, understanding,
reading and writing where there is no delay in non-verbal intelligence.
specific language impairment – a language disorder that delays the mastery of
language skills in children who have no hearing loss or other developmental
delays. SLI is also called developmental language disorder, language delay, or
developmental dysphasia.

19. Sensory impairments
Blindness
A link between communication skills and visual impairment with
children who are blind is currently being investigated.
Deafness/frequent ear infections
Trouble with hearing during language acquisition may lead to spoken
language problems. Children who suffer from frequent ear infections
may temporarily develop problems pronouncing words correctly. It
should also be noted that some of the above communication disorders
can occur with people who use sign language. The inability to hear is
not in itself a communication disorder.

20. Aphasia
Aphasia is loss of the ability to produce or comprehend language. There are acute aphasias which result from
stroke or brain injury, and primary progressive aphasias caused by progressive illnesses such as dementia.
 Acute aphasias
• Expressive aphasia also known as Broca's aphasia, expressive aphasia is a non-fluent aphasia that is
characterized by damage to the frontal lobe region of the brain. A person with expressive aphasia usually
speaks in short sentences that make sense but take great effort to produce. Also, a person with expressive
aphasia understands another person's speech but has trouble responding quickly.
• Receptive aphasia also known as Wernicke's aphasia, receptive aphasia is a fluent aphasia that is
categorized by damage to the temporal lobe region of the brain. A person with receptive aphasia usually
speaks in long sentences that have no meaning or content. People with this type of aphasia often have
trouble understanding other's speech and generally do not realize that they are not making any sense.
• Conduction aphasia
• Anomic aphasia
• Global aphasia
 Primary progressive aphasias
• Progressive nonfluent aphasia
• Semantic dementia
• Logopenic progressive aphasia

21. Learning Disability
Dyscalculia
A defect of the systems used in communicating numbers
 Dyslexia
A defect of the systems used in reading
Dysgraphia
A defect in the systems used in writing

22. Speech Disorder
cluttering - a syndrome characterized by a speech delivery rate which is either abnormally fast,
irregular, or both.
dysarthria - a condition that occurs when problems with the muscles that helps a person to talk
make it difficult to pronounce words.
esophageal voice - involves the patient injecting or swallowing air into the esophagus. Usually
learnt and used by patients who cannot use their larynges to speak. Once the patient has forced the
air into their esophagus, the air vibrates a muscle and creates esophageal voice. Esophageal voice
tends to be difficult to learn and patients are often only able to talk in short phrases with a quiet
voice.
lisp - a speech impediment that is also known as sigmatism.
speech sound disorder - Speech-sound disorders (SSD) involve impairments in speech-sound
production and range from mild articulation issues involving a limited number of speech sounds to
more severe phonologic disorders involving multiple errors in speech-sound production and
reduced intelligibility.
stuttering - a speech disorder in which sounds, syllables, or words are repeated or last longer than
normal. These problems cause a break in the flow of speech (called disfluency).

23. Thanks