Learning disability Flashcards
Define learning disability.
Impairment in CNS developing in the early period, presenting in childhood with reduced intellectual preformance and ability to acquire life skills.
Levels of intellectual disability
ICD-10 uses IQ to classify levels of learning disability
- Mild: 50-70
- Moderate – 35-50
- Severe – 20-35
- Profound<20
Explain the aetiology/risk factors for learning disability.
Mild to low range of low IQ
Associated with lower SE
Strong correlation with sibling IQ and 1st degree relative
Often associated with ASD – social, communication and repetitive rhythms. High % of epilepsy, sensory or motor deficits coexisting.
What are some genetic risk factors for a learning disability?
Chromosomal: Downs
Mendelian autosomal dominant: Neurofibromatosis, tuberous sclerosis
Mendelian autosomal recessive: Phenylketonuria
Sex-linked: Fragile X
Other: Prader-Willi Syndrome, Velocardiofacial syndrome
What is a structural risk factor for a learning disability?
Hydrocephalus
What are some brain damage related risk factors for a learning disability?
Antenatal: Infection, toxic, hypoxia, maternal disease
Natal: Birth asphyxia, intracranial bleed
Postnatal: Infection, injury, epilepsy, hypothyroid
What are common comorbid conditions associated with learning disabilities?
Autism
Epilepsy
Cerebral palsy
Hearing impairment
Visual impairment
Psychiatric disorder
Physical disability
Summarise the epidemiology of learning disabilities.
2% population - Mild 80%, Moderate 12%, Severe 8%
What are signs of a learning disability?
- Delay in usual developmental milestones
- Difficulty managing school work as well as other children
- Behavioral problems
- *Adolescent:** Difficulties with peers, inappropriate sex behavior, difficulty transitioning to adulthood.
- *Adult:** Every day functioning difficulties, require extra support, problem with social development.
How are learning disabilities assessed?
Obtain collateral history from parent on milestones
Enquire about pregnancy and birth problems (full paeds hx)
FHx of LD
Assess functional life skill and neuropsychological functioning.
Screen for comorbid psychiatric or medical disease.
What are investigations for learning disabilities?
FBC, U+Es, TFTs, LFTs, Glucose
Serology
EEG
Neuroimaging
Keryotype
What is the management for learning disabilities?
MDT approach: Psych, OT, PT, SALT, nurse, educational support.
Treat comorbidities as separate medical and psychiatric problems to improve overall functioning and learning. Give information on support groups. Behavioural treatments to teach certain skills. Medication not certified to be efficacious (low dose antipsychotics).
What are complications associated with learning disabilities? What is the prognosis of learning disabilities?
Higher prevalence of psychiatric comorbidities.
Difficulty to diagnose due to language difficulties and atypical presentation.
What are features of Down’s syndrome?
Features: Small head, round face, single palmar crease, hypotonia, cardiac and GI issues, deafness, AD, leukemia risk, low set ears, upslantic eyes
Genetics: 1/600 births, commonest single cause mental retardation (33%)
IQ 30-70
What are the features of Fragile X syndrome?
Prominent ears, facial hypoplasia and progmathism, macroorchidism in adolescence, cartilage issues (Joint lax/flat feet/MV prolapse).
Epilepsy in 23% in adolescence.
Explain the genetics of Fragile X syndrome.
1/4000 males, 1/8000 females
Deficiency in FMR1
Expansion of CGG trinucleotide repeats on X chromosome (Normal 5-20, Fragile X has 200+ repetitions)
What are the associations between Fragile X syndrome and learning disabilities?
IQ boys
Cognitive deficits – Short term visuospatial deficits, impaired motor planning, repetitive and impulsive interactional style
Autism like behaviors, difficulty maintaining eye contact, social anziety
Immature syntax and preservative language
Autism rate 5% and vice-versa in autism
What are the features of tuberous sclerosis?
Skin lesions: Wood’s light examination shows spots of hypopigmentaton. Adenoma sebecum. Shagreen patch in lumbosacral region
Epilepsy – Infantile spasms
CT scan shows tubers in ventricles from 4yo
Prevalence: 1/6000, autosomal dominant but 2/3 of cases are form de novo mutations
Explain the genetics of tuberous sclerosis.
Two genes can cause disorder:
TSC1 – harmatin , TSC2 - tuberin
Harmatomas can be found in any tissue – slow growing tumor, at rate of body tissues, with body tissue components in it
Neural abnormalities: Retardation, cortical dysplasia, astrocytomas
Large variation in severity
What are the associations between tuberous sclerosis and learning disabilities?
Early infantile spasms
Learning difficulty severity related to seizure occurrence
Cognitive: Dyspraxia, speech delay, dyscalculia
Childhood: ADHD, inattention in most
Association with autism in 50%
Emotional disorders and poor peer relationships in adolescence
