Intellectual disorders Flashcards
Is the term “mental retardation” still used?
Was known as this term by ICD-10 however was changed due to being offensive and outdated.
Now known as “disorder of intellectual development” by ICD-11.
What are the points that define intellectual disability?
- Impaired intellectual functioning (e.g. intelligence).
- Impaired social or adaptive functioning.
- Originating during development period
What conditions aren’t classed as intellectual disabilities?
Learning difficulties AKA specific learning difficulty
- Dyslexia
- Dyscalculia
- Dysgraphia
- Dyspraxia
Autism - however a LOT of autistic people do have intellectual disabilities and a lot of people with intellectual disabilities are autistic.
ADHD – BUT ADHD and ID are no longer considered mutually exclusive
Cerebral Palsy
Cognitive Decline
What is intellectual impairment?
Significantly below average intellectual functioning.
Tests for intellectual impairment?
Weschler intelligence scale for adults, children, and pre-schoolers.
Results for intellectual impairment?
Approx 2 or more standard deviations below the mean (approx less than 2.3rd percentile)
IQ less than 70
Test and results of social or adaptive dysfunction?
Vineland scale - an individually-administered measure of adaptive behaviour that is widely used to assess individuals with intellectual, developmental, and other disabilities.
Result -Deficits/Impairments in 2 or moreadaptive skills e.g.
Communication
Self-Care
Home Living
Social Skills
Community Use
Self-direction
Health and Safety
Functional Academics
Leisure and work
How many degrees of severity and what are the IQ ranges for intellectual disability?
4 degrees of severity
Mild – IQ 50-69 (85%)
Moderate – IQ 35-49 (10%)
Severe – IQ 20-34 (3-4%)
Profound – IQ <20 (1-2%)
In general,a person with a milder degree of disability may need support in only some areas. true/false?
True
Common areas of difficulty in mild degree of learning disability?
Common areas of difficulty would include budgeting,making plans, managing time.
When the learning difficulty is more severe, what example tasks would the patient struggle with?
limited communication, very significantly reduced ability to learn new skills, and to need support with daily activities such as dressing, washing, eating, and mobility.
Causes of intellectual/learning disability?
There are many different causes of learning or intellectual disability
In some patients there is a single,discrete cause
In many however we label it as idiopathic or suggest multifactorial causes
Anything which impacts the development of the brain can lead to LD(learning disabilities)
Average case of mild learning disability? (IQ: 50-69)
“Mental age” 9 to 12 years.
Delayed speech – but typically able to use everyday speech eventually
Often exhibit difficulties in the acquisition and comprehension of complex language concepts and academic skills.
Most master basic self-care, domestic, and practical activities.
Can generally achieve relatively independent living and employment as adults but may require appropriate support.
Average case of moderate learning disability? (IQ: 35-49)
“Mental age” 6 to 9 years
Language and capacity for acquisition of skills are generally limited to basics.
Some may master basic self-care, domestic, and practical activities.
Most require considerable and consistent support to achieve independent living and employment
Usually fully mobile
Majority have organic aetiology
Epilepsy and Physical Disabilities common
Discrepant “bumpy/spiky” profiles seen
Average case of severe learning disability? (IQ: 20-34)
“Mental age” 3 to 6 years
Epilepsy very common
Affected persons exhibit very limited language and capacity for acquisition of academic skills.
They may also have motor impairments and typically require daily support in asupervised environment for adequatecare butmay acquire basic self-care skills withintensive training.
Average case of profound learning disability? (IQ:<20)
Difficult to measure IQ reliably at this level
“Mental age” less than 3 years
Affected persons possess very limited communication abilities and capacity foracquisition of academic skills is restricted to basic concrete skills.
They may also have co-occurring motor and sensory impairments and typicallyrequire daily support in a supervised environment for adequate care.
Single gene disorder causes of learning disability?
Fragile X
Phenylketonuria
Rett
Lesch-Nyhan
Copy number variants/microdeletion/duplication causes of learning disability?
DiGeorge
Prader-Willi
Angelman
Cri du chat
Chromosomal disorder causes of learning disability?
Down’s Syndrome (Trisomy 21)
Patau Syndrome (Trisomy 13)
Edward’s Syndrome (Trisomy 18)
Turners (45, XO)
Trisomy X (47, XXX)
Klinefelter (XXY)
Common physical features of fragile X syndrome?
Prominent, broad forehead
Long face
Large ears
Crowding high arched palate
Squint
Hollow chest
Hypotonia
Symptoms of fragile x syndrome?
Autism spectrum disorders
Intellectual disability
Distinct facial features
Incidence of fragile x syndrome?
Incidence 1:4000 males /1:8000 females
Genetics behind fragile x syndrome?
FMR1 Gene
X linked dominant with variable penetration (possibly outdated )
Large sequence of CGG repeats at a fragile site on X chromosome
What is Phenylketonuria?
Preventable cause of Severe LD due to deficiency of an enzyme called phenylalanine hydroxylase
How is phenylketonuria diagnosed?
Diagnosed postnatally (Guthrie Test)
Phenylketonuria clinical features?
Clinical Features
Fair hair/skin and blue eyes
Neurological signs (stooped posture/broad-based gait/increased tone and reflexes/tremor/stereotyped movements)
Behavioural Problems (Hyperactivity/temper tantrums/perseveration/echolalia)
Management of phenylketonuria?
Supervised early dietary restriction of pheylalanine (found in most protein-containing foods i.e. milk, eggs, cheese, nuts, chicken etc).
Prognosis of phenylketonuria?
Lower than average IQ even with dietary restriction
What is Rett syndrome?
a rare genetic neurological and developmental disorder that affects the way the brain develops. This disorder causes a progressive loss of motor skills and language. Mainly present in females
Clinical features of Rett syndrome?
Initially Normal Development followed by 4 stages:
Early Onset Developmental Arrest
Rapid destructive/regressive
Plateau
Late motor deterioration
Aetiology of Rett syndrome?
Mutations in MECP2 gene on X chromosome present in most girls with Rett’s
Prognosis of Rett syndrome?
Poor with motor deterioration and severe LD (learning disability)
Gene therapy
Aetiology of Di George syndrome?
Microdeletion (small chromosomal deletion) of 22q11
Clinical features of Di George syndrome?
LD (learning disability)
Cardiac Abnormalities (Tetralogy of Fallot/VSD/Interrupted aortic arch/Pulmonary atresia/truncus arteriosis)
Facial Features
Hypocalcaemia (low blood calcium)
Hypospadias (opening of urethra on underside of penis)
Aetiology of Prader - Willi syndrome?
Microdeletion 15q11-q13 (paternal copy)
Prader-willi is more common in males. true/false?
True
M:F ratio is 4:3
Clinical features of Prader-willi?
Massive hyperphagia(greater desire for food)
Compulsive food seeking, marked obesity
Short stature, hypogenitalism, behavioural disorders, mild/moderate LD, speech abnormalities and sleep disturbance in Childhood/Adolescence.
How is Angelman syndrome similar to Prader-willi syndrome?
Microdeletion of the same 15q11-q13 gene however in Angelman syndrome it is maternal copy instead of paternal copy.
Clinical features of Angelmans syndrome?
Ataxia
Epilepsy (86%)
Paroxsysms of laughter (uncontrollable bursts of laughter)
Absence of speech
Facial Features
Severe/Profound LD
Hand flapping/tongue thrusting/mouth movements
URTIs/ear infections/obesity
Cri du chat is caused by deletion of short arm of chromosome 7. true/false?
False
Short arm of chromosome 5
Clinical features of Cri du chat?
Small children with microcephaly
Hypertelorism (increased distance between eyes), and downward slant of eyes.
Small chin
Low set ears
Nose broad and “beak like”
Down syndrome (trisomy 21) can present with instability of the atlantoaxial joint. true/false?
True
Hand appearance of patient with Down syndrome?
Square palm with palmar crease
Wide gap between thumb and second finger
Short stubby fingers
Are umbilical hernias common in Down syndrome?
Yes
Hair is usually unaffected in down syndrome. true/false?
false
hair features: Dry, sparse and fine – some have focal alopecia
Patau syndrome present with an extra chromosome 12? true/false?
false
extra chromosome 13 (trisomy 13)
kleinfelter’s syndrome (XXY) only occurs in males. true/false?
True
What is kleinfelter’s syndrome development like and what are some clinical features?
Development normal until puberty
Secondary sexual characteristics fail to develop – Treated with Testosterone
Testes small/undescended
Body hair sparse
c. 30% males show moderately severe gynaecomastia
Appearance of kleinfelter’s patient?
Long lower limbs
Taller than average
What does kleinfelter’s increase the risk of?
leg ulcers
Osteoperosis
Breast Cancer
Psychosis
What is the difference between learning difficulties and learning disabilities?
A learning difficulty does not affect general intelligence, whereas a learning disability is linked to an overall cognitive impairment. Some examples of specific learning difficulties are: dyspraxia.
What is Guthrie test for Phenylketonuria?
detects phenylalanine in the blood of newborns, enabling for early diagnosis of PKU. Early diagnoses of PKU prevent the development of mental disabilities
