PSY345 Atypical brain development and degeneration
Lecture 1
Diagnosis and key facts;
- Diagnostic processes differ between the various conditions
- Quality of evidence bases also differs between conditions due to prevalence of the
condition, heterogeneity and practical constraints
What is meant by cognition and behaviour?
- Cognition refers to how we think and learn e.g. language, attention and memory
- Behaviour refers to how we act and interact with others
Intervention, support and context
- Certain issues are syndrome specific and certain issues are common across
syndromes
Introduction into neurodevelopmental conditions
- Neurodevelopmental conditions refer to conditions that are associated with atypical
brain development
- ‘ Conditions that are of a genetic or multifactorial origin that result in one or more
specific cognitive difference. These differences are present early in life and extend
into adult life without showing relapse or remission’
Diagnoses
1. Referral, typically from a GP or health visitor in the case of young children
2. Formal assessment (NHS), usually diagnosis is made by a clinical psychologist or
clinical geneticist. This may be a multi-disciplinary diagnostic assessment based on
DSM-5 / ICD-11 criteria
3. Post diagnostic support e.g. in school support such as speech and language therapy
Certain conditions have an establishes genetic basis. These are known as chromosomal
disorders. For example downs syndrome which is caused by the presence of all or part of a
third copy of chromosome 21. DS is the most common chromosome abnormality in humans.
The physical growth delays, a particular set of facial characteristics and intellectual disability
is also associated with the condition.
Another example of a condition with an established genetic basis is sotos syndrome. It is
resulted from mutations in the NSD1 gene on chromosome 5. It causes physical overgrowth
during the first years of life. Children with sotos syndrome are often taller heavier and have
larger heads than their peers. They often have intellectual disabilities.
,Certain conditions have a less clear genetic basis. For example autism spectrum disorder.
This has a complex genetic basis where 1000s of genes are implicated. It is unclear whether
ASD is explained more by rare mutations or by rare combinations of common genetic
variants. Currently there is no genetic test diagnosis is made on the basis of behaviour.
The development of neurodevelopmental conditions
- Each individual changes and develops over time
- There is a complex interaction of genes and environment e.g. in utero (maternal diet
or stress). The early years can also be a critical period.
Neurodiversity
- An approach to learning and disability that suggests that diverse neurological
conditions appear as a result of normal variations in the human genome.
Neurological differences should be recognised and respected as a social category.
- We should use terms such a s neurotypical or non-neurotypical
- Avoid ableist language
Methodology for studying neurodevelopmental conditions
- Population based prevalence studies
- Behavioural observation
- Parent/ teacher questionnaires
- Behavioural experiments such as eye tracking
- Cognitive neuroscience experiments such as EEGs and fMRIs
- Semi structured interviews
Fragile X syndrome
- The differences in the brain of
people with typical brain
development and nontypical brain
development can be seen in
differences of grey matter and
white matter
- Grey matter = cell bodies,
dendrites and axon terminals
- White matter = axons connecting
different parts of grey matter to
each other
,Differences in the brain at 1-3 years
- Voxel-wise grey and white matter volumes comparison
- 2 year period assessed in 1-3 year old boys with FXS
- There were and development matched controls
- Enlarged GMV in the caudate, thalamus, and fusiform gyri
- Reduced GMV in cerebellar vermis
- WMV of striatal-prefrontal regions was greater in FXS
- Suggests early, possibly prenatal, genetically mediated alterations in
neurodevelopment and disrupted synaptic pruning
Physical features in those with fragile X
- Long, narrow face
- Prominent jaw
- Prominent ears
- Flat feet
Common features
- Short attention span
- Distractibility impulsiveness
- Restlessness
- Over activity
- Sensory problems
- Social difficulties
- Emotional difficulties
- Communication difficulties
Co-occurance
- Dual diagnosis of autism is common
- 50-90% have autistic symptoms
- 25-80% have ASD diagnoses
- Prevalence of ADHD symptoms in children with FXS is between 54% and 59%
- Epilepsy is also quite common
Common strengths
- Imitation
- Visual learning
- Personable e.g. sensitive or sense of humour
, Cognitive and behavioural profiles;
First signs of FXS
- Sensory motor atypicality’s at 9-12 months
- Decreased object play
- Increased leg stereotypies
- Atypical posturing
- Prolonged visual attention to objects
- Missing milestones may alert parents to seek medical advice
Adaptive behaviour
- Measured via vineland adaptive behaviour scales
- Assessed real life skills and independence
- Semi-structures parent interview on communication, daily living, socialisation and
motor skills
- Outcomes of this provide a variable trajectory
- Positive environmental influences may act as protective factors
Lecture 1
Diagnosis and key facts;
- Diagnostic processes differ between the various conditions
- Quality of evidence bases also differs between conditions due to prevalence of the
condition, heterogeneity and practical constraints
What is meant by cognition and behaviour?
- Cognition refers to how we think and learn e.g. language, attention and memory
- Behaviour refers to how we act and interact with others
Intervention, support and context
- Certain issues are syndrome specific and certain issues are common across
syndromes
Introduction into neurodevelopmental conditions
- Neurodevelopmental conditions refer to conditions that are associated with atypical
brain development
- ‘ Conditions that are of a genetic or multifactorial origin that result in one or more
specific cognitive difference. These differences are present early in life and extend
into adult life without showing relapse or remission’
Diagnoses
1. Referral, typically from a GP or health visitor in the case of young children
2. Formal assessment (NHS), usually diagnosis is made by a clinical psychologist or
clinical geneticist. This may be a multi-disciplinary diagnostic assessment based on
DSM-5 / ICD-11 criteria
3. Post diagnostic support e.g. in school support such as speech and language therapy
Certain conditions have an establishes genetic basis. These are known as chromosomal
disorders. For example downs syndrome which is caused by the presence of all or part of a
third copy of chromosome 21. DS is the most common chromosome abnormality in humans.
The physical growth delays, a particular set of facial characteristics and intellectual disability
is also associated with the condition.
Another example of a condition with an established genetic basis is sotos syndrome. It is
resulted from mutations in the NSD1 gene on chromosome 5. It causes physical overgrowth
during the first years of life. Children with sotos syndrome are often taller heavier and have
larger heads than their peers. They often have intellectual disabilities.
,Certain conditions have a less clear genetic basis. For example autism spectrum disorder.
This has a complex genetic basis where 1000s of genes are implicated. It is unclear whether
ASD is explained more by rare mutations or by rare combinations of common genetic
variants. Currently there is no genetic test diagnosis is made on the basis of behaviour.
The development of neurodevelopmental conditions
- Each individual changes and develops over time
- There is a complex interaction of genes and environment e.g. in utero (maternal diet
or stress). The early years can also be a critical period.
Neurodiversity
- An approach to learning and disability that suggests that diverse neurological
conditions appear as a result of normal variations in the human genome.
Neurological differences should be recognised and respected as a social category.
- We should use terms such a s neurotypical or non-neurotypical
- Avoid ableist language
Methodology for studying neurodevelopmental conditions
- Population based prevalence studies
- Behavioural observation
- Parent/ teacher questionnaires
- Behavioural experiments such as eye tracking
- Cognitive neuroscience experiments such as EEGs and fMRIs
- Semi structured interviews
Fragile X syndrome
- The differences in the brain of
people with typical brain
development and nontypical brain
development can be seen in
differences of grey matter and
white matter
- Grey matter = cell bodies,
dendrites and axon terminals
- White matter = axons connecting
different parts of grey matter to
each other
,Differences in the brain at 1-3 years
- Voxel-wise grey and white matter volumes comparison
- 2 year period assessed in 1-3 year old boys with FXS
- There were and development matched controls
- Enlarged GMV in the caudate, thalamus, and fusiform gyri
- Reduced GMV in cerebellar vermis
- WMV of striatal-prefrontal regions was greater in FXS
- Suggests early, possibly prenatal, genetically mediated alterations in
neurodevelopment and disrupted synaptic pruning
Physical features in those with fragile X
- Long, narrow face
- Prominent jaw
- Prominent ears
- Flat feet
Common features
- Short attention span
- Distractibility impulsiveness
- Restlessness
- Over activity
- Sensory problems
- Social difficulties
- Emotional difficulties
- Communication difficulties
Co-occurance
- Dual diagnosis of autism is common
- 50-90% have autistic symptoms
- 25-80% have ASD diagnoses
- Prevalence of ADHD symptoms in children with FXS is between 54% and 59%
- Epilepsy is also quite common
Common strengths
- Imitation
- Visual learning
- Personable e.g. sensitive or sense of humour
, Cognitive and behavioural profiles;
First signs of FXS
- Sensory motor atypicality’s at 9-12 months
- Decreased object play
- Increased leg stereotypies
- Atypical posturing
- Prolonged visual attention to objects
- Missing milestones may alert parents to seek medical advice
Adaptive behaviour
- Measured via vineland adaptive behaviour scales
- Assessed real life skills and independence
- Semi-structures parent interview on communication, daily living, socialisation and
motor skills
- Outcomes of this provide a variable trajectory
- Positive environmental influences may act as protective factors
