Arrested Intellectual Development: Learning Disability Flashcards
Various terms used in the place of learning disability?
Mental retardation (this is not used clinically but is used in ICD-10, etc)
Mental handicap (used in legislation)
Learning disability
Intellectual disability
Intellectual developmental disorder (being used now)
Co-morbidities with learning disability?
Many will have comorbid conditions, e.g:
• Epilepsy occurs in 1/3rd of patients with learning disability
• Cardiac issues in Down’s syndrome
Define learning disability?
Condition of arrested or incomplete development of the mind, which is esp. characterised by impairment of skills, manifested during the developmental period; this contributes to the overall level of intelligence (cognitive, language, motor and social abilities)
Criteria for a learning disability diagnosis?
IQ <70
Developmental aetiology (<18 years)
Deficits in adaptive functioning, e.g: school class, no exam results, no work, not married, no driver’s license, management of ADLs difficult, unable to look after children
Psychometric assessments used when considering learning disability?
Most common is Weschler Adult Intelligence Scale (WAIS)
Others used include:
• Stanford Binet
• Raven’s Progressive Matrices
What is the average IQ?
100
Prevalence of an IQ <70 in the general population?
3% (only ~1-1.5% are known to services)
Explain the Flynn effect
Average IQ has been rising by ~3 IQ points per decade
It is slowing down, esp. in developed countries
NOTE - there has also been an increase in attention and in semantic & episodic memory
Theorised causes of the Flynn effect?
Schooling
Test familiarity (internet sources of the same tests used formally)
Stimulation
Nutrition
Infection
What conditions are not classed as a learning disability?
Dyslexia or any other educational difficulty, i.e: a learning difficulty is not the same as a learning disability
Learning disability is not something that happens to an adult, e.g: dementia, acquired brain injury, etc
Cognitive decline due to chronic psychosis
Methods of determining if a patient has a learning disability?
May be immediately apparent, e.g: a genetic syndrome, dysmorphic features
Info from the patient themselves or a carer
Hx of special schooling
Behaviour and communication of the patient
Types of learning disability, according to severity?
Mild LD - IQ 50-69, mental age of 9 to <12 years
Moderate LD - IQ 35-49, mental age of 6 to <9 years
Severe LD - IQ 20-34; mental age of 3 to <6 years
Profound LD - IQ <20, mental age <3 years
Borderline LD - IQ 70-84,
mental age of 12 to under 15 years (this is an unofficial category, as an IQ >70 is technically not an LD)
Most common type of LD?
Mild LD
NOTE - mild LD rarely has an organic aetiology
Features of mild LD?
Delayed speech but able to use everyday speech
Full independence (self-care, practical and domestic skills)
Difficulty reading/writing
Capable of unskilled / semi-skilled work
Problems, if they have social or emotional immaturity
Features of moderate LD?
Slow with comprehension and language
Limited achievements
Delayed self-care and motor skills
Simple practical tasks (often with supervision)
Usually fully mobile (physically active)
Cause of moderate LD?
Majority have an organic aetiology
Co-morbidities with moderate LD?
Epilepsy and physical disability are common
Features of severe LD?
Generally, more marked impairment than in moderate LD
Achievements are more restricted
Co-morbidities with severe LD?
Epilepsy
Features of profound LD?
Severe limitation in ability to understand or comply with requests or instructions
Little/no self-care
Often, severe mobility restriction
Basic/simple tasks may be acquired
Aetiology of learning disabilities?
At conception, there are genetic and chromosomal factors
During the antenatal period: • Maternal infections (Rubella, CMV, Toxoplasmosis) • Poor diet • Substance abuse (medication or drugs) • Alcohol (foetal alcohol syndrome) • Poor diet
At birth: • Extreme prematurity • Birth injury • Neonatal septicaemia • Pneumonia • Meningitis/encephalitis • Cerebral anoxia • Respiratory distress
During the post-natal period:
• Metabolic causes
• Hypoglycaemia
• High bilirubin
During infancy/childhood:
• Infections
• NAI, trauma, toxins
Chromosomal conditions the cause learning disability?
Down’s syndrome (trisomy 21) - IQ 30-55
Alzheimer’s disease and Down’s syndrome?
Most patients with Down’s syndrome will develop changes assoc. with Alzheimer’s dementia by the time they are in their 40s
Other chromosomal defects that cause a learning disability?
Pateau syndrome (trisomy 13)
Edward’s syndrome (trisomy 18) -
cri du chat 5P - causes microcephaly and severe/profound LD
Angelman 15Q - maternally derived; causes LD, ataxia, paroxysms of laughter
Prader-Willi 15Q - paternally derived; causes LD, over-eating, self-injurious behaviour
Velo-cardiofacial syndrome 22Q - 1/2 have a LD; there is an increased risk of schizophrenia
William’s syndrome 7Q
