Neurodevelopmental disorders

Question 1

Diagnostic features of ADHD

Answer 1

Hyperactivity

Inattention

Impulsivity

Onset in childhood (<12/<7 for ICD), inconsistent with developmental stage

Pervasive (>1 setting e.g. home + school) + present for >=6mo

Question 2

Aetiology of ADHD

Answer 2

• Biological
  
  • Strong heritability (FDR 5x risk)
  • Mothers who used drugs/alcohol/tobacco during pregnancy
  • Prematurity, small for gestational age
  • Early brain injury/perinatal complications
• Psychological
  
  • Foster children/prolonged childhood deprivation
  • Abuse

Question 3

Differential diagnosis in ADHD

Answer 3

Sleep, visual, hearing problems

ASD

Anxiety

Intellectual disability

Brain injury

Question 4

Features of inattention in Hx

Answer 4

Poor performance at school

Struggling to organise themselves (need high parental scaffolding)

Question 5

Features of impulsivity in Hx

Answer 5

Higher risk taking behaviour

Frequent A&E attendances

Strained family/peer relationships

Question 6

Key components of developmental Hx

Answer 6

Pregnancy + prematurity

Walk + talk milestones

Sleep/feeding problems

Early temparement

Development of social + communication skills

Question 7

Assessment questionairres for ADHD

Answer 7

C-GAS: assessing impairment

QB+ test: High Sens, low Sp

SDQ/SNAP/Conner’s: Diagnostic standardised tests

Question 8

Common comorbidities with ADHD

Answer 8

ASD (20-50% of ADHD will have ASD)

Depression, anxiety

Tic disorders

Dyspraxia/dyslexia

Sleep disorder

Conduct disorder/ODD

Dissocial PD/substance misuse develops later

Question 9

Gender ratio for ADHD

Answer 9

2-3x more common in males (may be underdiagnosed due to ‘atypical’ more inattentive presentation in females)

Question 10

Neurotransmitter system implicated in ADHD

Answer 10

Low D2/D3 receptors in basal ganglia

Question 11

Prognosis for ADHD

Answer 11

• 50-60% one or more core symptoms into adulthood
  
  • Over-activity lessens
  • Impulsivity, risk-taking, poor concentration may worsen/stay same/improve
• 15-30% full ADHD syndrome
• Problems with substance misuse, criminal record, poor academic/career achievement

Question 12

Non-pharmacological interventions for ADHD

Answer 12

Mixed evidence, esp if using blinded assessors

Classroom: Teacher awareness + special strategies (e.g. fiddle toys, movement breaks)

Parent: Training, NICE recommended, better evidence for conduct disorder

Behavioural/social skills training: For child

Psychological: CBT, better evidence for adolescents esp w/ comorbidities (pref on meds)

Question 13

Efficacy of ADHD medication

Answer 13

70% symptomatic response (but no cure)

Brain changes in adult populations –> more normal

Question 14

Pharmacological treatments for ADHD

Answer 14

1st line: Methylphenidate 6w trial (psychostimulant)

2nd line: lis-dexamphetamine 6w trial (psychostimulant)

3rd line: atomoxetine (NA RI)

Inhibit reuptake of DA/NA

Question 15

Common side effects of ADHD medication

Answer 15

Neuro: headache, insomnia, tics

CVS: BP + pulse increase. Regular monitoring + ECG, esp if Hx of palpitations/syncope or FHx of SCD

Growth: Reduced in first 3 years, consider drug holidays for catchup

Psych: Psychosis, suicidality

GI: Nausea, weight loss, anorexia

Question 16

Core triad of symptoms for ASD

Answer 16

Impairment of social interaction/behaviour

Communication difficulties

Narrowing of interests/rigid + repetitive behaviour

Question 17

Features of impaired social functioning in ASD

Answer 17

Aloofness, egocentricity, reduced interest in others + difficulty sharing interests

Few/no sustained relationships, preference for solitude

Lack of awareness of social rules + reciprocity

Excessive/diminished stranger anxiety

Question 18

Features of communication difficulties in ASD

Answer 18

Poor nonverbal communication (pointing, gesturing, body posture)

Abnormal speech, pronoun reversal

Delayed development of smiling/pointing/speech (assessment in all <3yo with delays)

Pedantic speech ‘little professor’

Question 19

Features of rigid/repetitive behaviour in ASD

Answer 19

Stereotyped/repetitive speech or motor movements or use of objects

Adherence to routines/rituals + resistance to change (high transition anxiety)

Abnormal sensory sensitivity

Preoccupation with objects/topics, specific, fixed, intense

Question 20

Important differentials for ASD

Answer 20

ADHD (esp girls)

ID

Social anxiety

OCD

Question 21

Assessment for suspected ASD

Answer 21

• Screening tools: e.g. ADOS, DISCO; AQ for adults
• Multidiscplinary: Speech + lang, OT, EdPsych/SENCO at school
• Corroborative Hx: Parents, teachers, coaches

Question 22

Management of ASD

Answer 22

• Psychoeducation + signposting: E.g. National Autism Society, self-help books
• Liaising with school: For adjustments via SENCO/EdPsych
• Parental support groups/courses: e.g. All Things Autism
• Early intervention schemes: e.g. TEACCH, ESDM
• Psychological treatment: Social skills training (e.g. stories), SALT, behavioural training programs
• Comorbidity: Psychiatric, sensory (OT), ID/SpLD
• Melatonin: For sleep disturbance, if necessary

Question 23

M:F ratio for ASD

Answer 23

1.5-3:1

Dx may be missed in girls due to atypical presentation (‘masked’ behaviours and present later)

Question 24

Aetiology of ASD

Answer 24

Bio: 40-90% heritability (2-14% risk in siblings); altered brain connectivity esp frontal/parietal, empathy circuits, and corpus callosum

Psycho: Weak central coherence, ‘Mindblindness’, Executive dysf(x)

Question 25

Characteristics of learning disability

Answer 25

Reduced IQ (\<70) Impairment in social/adaptive funcitoning Onset \<18yo (i.e. during developmental period)

Question 26

IQ cutoff values for different LDs

Answer 26

**Mild:** 50-69 **Moderate:** 35-49 **Severe:** 20-35 **Profound:** \<20

Question 27

Prevalence of LDs

Answer 27

3% of general population, of which 85% mild 10% moderate 5% severe/profound

Question 28

Speech abnormalities across LD spectrum

Answer 28

**Mild:** Almost normal, simple content **Moderate:** Short sentences + not connected **Severe:** Limited speech, up to 10 words **Profound:** No speech

Question 29

Most common causes of severe LD

Answer 29

Down's Fragile X

Question 30

Key physical comorbidity in severe LD that needs to be managed

Answer 30

High seizure risk

Question 31

Physical features of fragileX syndrome

Answer 31

Large, protruding ears Large testes Lax joints Flat feet Long face

Question 32

Prevalence of psychiatric illness in population with LD

Answer 32

3x general population (Except unipolar depression, same prevalence)

Question 33

Confounders in psychiatric presentations in LD

Answer 33

Hypothyroidism/epilepsy/infection as common causes --\> must screen More likely to present with somatic/behavioural symptoms Grief timeline must be extended to allow for processing time

Question 34

Management of psychiatric conditions in those with LD

Answer 34

Similar to general population CBT may be more effective due to lack of intellectualisation

Question 35

Aetiology of Down's syndrome

Answer 35

Trisomy 21

Question 36

Aetiology of fragile X syndrome

Answer 36

Triplet repeat in FMR1 on X chromosome

Question 37

Aetiology of Prader-Willi syndrome

Answer 37

Deletion on chromosome 15 from *father* (c.f. Angelman)

Question 38

Clinical features of Prader-Willi syndrome

Answer 38

Obesity Hypogonadism Compulsive eating (esp of inedible things) Psychosis LD

Question 39

Clinical features of Williams syndrome

Answer 39

Hypercalcaemia Elfin like appearance LD - affects visuospatial \> verbal

Question 40

Incidence of Down's

Answer 40

1/1000 live births

Question 41

Incidence of fragile X

Answer 41

1/1500 live births

Question 42

Prenatal causes of LD

Answer 42

**Infections:** HIV, syphillis, Rubella, CMV, toxoplasmosis **Exposure:** Drugs, alcohol, radiation **Nutrition:** Placental insufficiency, maternal malnutrition **Psychiatric:** Maternal schizophrenia, untreated unipolar depression **Genetics:** Chromosomal abnormalities, single gene disorders, SNPs

Question 43

Perinatal causes of LD

Answer 43

V high or low birth weight Asphyxia Hypoglycaemia, hypothyroidism, hyperbilirubinaemia

Question 44

Postnatal causes of LD

Answer 44

**Infections:** Meningitis, encephalitis ## Footnote **Head injury** **Hypoxia** **Brain tumours**

Question 45

Scale for calculating mental age and relationship to IQ

Answer 45

Stanford-Binnett Intelligence Scale Mental age/chronological age (max 18) = approx IQ

Question 46

Mechanism of action of amphetamines

Answer 46

Competitive substrate of VMAT --\> displaces NA/DA out of synpatic vesicles Weak reuptake + MAO inhibitor

Question 47

Normal age for development of theory of mind (i.e. passing Sally-Anne test)

Answer 47

3-4yo

Question 48

Physical illness associations with ASD

Answer 48

Tuberous sclerosis PKU Epilepsy

Question 49

Heritability of ASD

Answer 49

Approx 80%

Question 50

Prevalence of ASD in UK

Answer 50

1%

Question 51

Risk of ASD if sibling has ASD

Answer 51

4-17% (varies depending on order, gender mismatch)

Question 52

Indications for medications in ADHD

Answer 52

Failure of psychosocial interventions in moderate ADHD Severe ADHD