Development Flashcards
What factors influence normal development?
- genetic
- nutritional
- environmental
Define median age
‘age when 50% of the population achieve a skill’
Define limit age
‘age when skill should have been acquired by 97.5% of children’
Describe gross motor development within the first 6 weeks of life
Head control in vertical
Describe gross motor development within the first 3 months of life
No head lag on pulling to sit
Describe gross motor development within the first 6 months of life
Sits unsupported, weight bears on legs
Describe gross motor development within the first 9 months of life
Crawls, holds onto furniture to stand and reaches on
Describe gross motor development within the first 12 months of life
Pulls to standing, walks
Describe gross motor development within the first 18 months of life
Runs, climbs onto adult chair
Describe gross motor development by 2 years of age
Climbs stairs with two feet/step, sits and steers trike
Describe gross motor development by 3 years of age
Climbs stairs using alternate feet, jumps off bottom step
Describe gross motor development by 4 years of age
Hops and climbs ladders
Name five primitive reflexes
Sucking and Rooting Palmar and Plantar grasp ATNR Moro Stepping and Placing
Describe the fine motor and vision development at 6 weeks
Follow torch with eyes
Describe the fine motor and vision development at 3 months
Hand regard in midline
Describe the fine motor and vision development at 6 months
Grasps toys, hand in hand
Describe the fine motor and vision development at 9 months
Scissor grip, points with index finger
Describe the fine motor and vision development at 12 months
Pincer grasp, bangs toys together
Describe the fine motor and vision development at 18 months
Tower of 3-4 bricks
Describe the fine motor and vision development at 2 years
Tower of 6-7 bricks, scribbles
Describe the fine motor and vision development at 3 years
Tower of 9 bricks, copies circle
Describe the fine motor and vision development at 4 years
Threads beads, draws simple man
Describe hearing and language development at 6 weeks
Stills to voice
Describe hearing and language development at 3 months
Starts to vocalise
Describe hearing and language development at 6 months
Babbles, screams when annoyed
Describe hearing and language development at 9 months
Imitates sounds, localises sound
Describe hearing and language development at 12 months
Knows and turns to name, many vowels and consonants
Describe hearing and language development at 18 months
5-20 words
Describe hearing and language development at 2 years
Simple instructions, 50+ words
Describe hearing and language development at 3 years
Asks questions, complex instructions, nursery rhymes
Describe hearing and language development at 4 years
Tells stories, counts to 20
Describe social and play development at 6 weeks
Social smile
Describe social and play development at 3 months
Pleasure on friendly handling
Describe social and play development at 6 months
Plays with feet, friendly with strangers
Describe social and play development at 9 months
Plays peek-a-boo, distinguishes strangers
Describe social and play development at 12 months
Drinks from a cup, waves bye bye
Describe social and play development at 18 months
Feeds with a spoon
Describe social and play development at 2 years
Puts on some clothes, symbolic play
Describe social and play development at 3 years
Toilet trained, washes hands, pretend interactive play
Describe social and play development at 4 years
Dresses and undresses, washes/dried hands, understands taking turns
Define developmental delay
Failure to attain appropriate developmental milestones for child’s correct chronological age
Name three types of abnormal development
- delay (global/specific)
- deviation (autism)
- regression (Rett’s syndrome, metabolic disorders)
What is Rett’s Syndrome?
Genetic condition where children develop normally in first year and then plateau before losing developmental skills
States seven red flags for abnormal development
- Asymmetry of movement
- Not reaching for objects by 6 months
- Unable to sit supported by 12 months
- Unable to walk by 18 months
- No speech by 18 months
- Concerns re. vision or hearing
- Loss of skills
What is global developmental delay?
Significant delay in 2 or more; gross/fine motor speech/language cognition social/personal ADL
What does Down’s syndrome screening consist of?
- cardiac
- vision
- hearing
- thyroid (annual)
- sleep related breathing disorders
- growth/development charts
- genetic
What is the genetic defect in Down’s syndrome?
trisomy 21
What is the IQ range of a mild learning disability?
IQ 50-70
What is the IQ range of a severe learning disability?
IQ <50
What are specific developmental delays?
Delay in one of the subsections for development
State three motor delays
- duchenne muscular dystrophy
- cerebral palsy
- co-ordination disorders
Name a language delay
Specific language impairment
Name two sensory delays
Oculocutaneous albinism
Treacher-Collins
Name a developmental deviation
Autism Spectrum disorders
Describe Duchenne Muscular Dystrophy
X-linked recessive disorder which impacts all muscles and often presents with speech delay. Ultimately life limiting, patients have calf pseudohypertrophy but muscles have no increased tone. Lordosis is common.
How is DMD investigated and what is the clinical test?
Measure CK - very high
Gower’s manoeuvre shows pelvic girdle weakness
What is cerebral palsy?
Group of disorders of development of movement/posture due to - disturbances to the foetus in utero/during delivery or insult after birth leading to neurological ischaemia and loss of inhibitory messages
What type is most cerebral palsy?
Spastic
Name the three types of spastic cerebral palsy
- hemiplegic (arm and leg on one side)
- diplegic (both legs)
- quadriplegic (both arms and legs)
Name some conditions associated with cerebral palsy
- mobility problems
- learning difficulties
- epilepsy
- visual/hearing impairment
- communication problems
- feeding/sleep problems
What does an MRI of cerebral palsy show?
Loss of white matter around ventricles
Describe oculocutaneous albinism
Autosomal recessive disease affecting the pigment in hair/skin/eyes
What do people with oculocutaneous albinism look like?
Very pale skin, light coloured hair and red eyes
What eye problems can present in oculocutaneous albinism?
astigmatism
nystagmus
What is hydrocephalus?
Build up of fluid on the brain which can cause serious problems including visual impairment
What will an MRI of hydrocephalus look like?
Enlarged ventricles
What causes hydrocephalus?
Spina bifida, mumps, rubella in utero
How is hydrocephalus treated?
Ventriculoperitoneal shunt
What is a middle ear effusion?
Build up of secretions behind the ear drum leads to conductive hearing loss - separation of air and bone conduction
Other than conductive what is the other type of hearing loss?
Sensorineural - equal air and bone conduction
How is an ear effusion treated?
Temporary grommets to drain fluid and keep eardrum open
In terms of the CNS what do genes determine?
- the correct sequence of brain development from conception to neuronal proliferation, migration and reorganisation
- development of dendritic and axonal interconnections
- development of synapses, receptors and neurotransmitters
Other than genes what is another key factor in CNS development?
Environment
What contributes to the intrauterine environment?
- maternal health and disease
- insults which may be continuous throughout pregnancy (alcohol, CMV, rubella)
- placental function/nutrition
Give an example of a maternal disease that can impact the intrauterine environment
Maternal PKU - phenylalanine levels must be controlled otherwise excess may impact foetal brain development
What is the extrauterine environment made of?
- physical factors (nutrition, environmental toxins)
- emotional and social factors (neglect, lack of stimulation)
- exposure to drugs, alcohol and other substances
When is the embryonic period?
Conception - week 8
Name the two layers the embryo starts as
Epiblast and hypoblast
After the formation of the epiblast and hypoblast what happens?
Streak develops with a primitive node
What are the opposite ends of the embryo called?
Rostral (top)
Caudal (bottom)
What determines the way the cells migrate?
Nodal signalling
What layer do the cells migrate within?
Mesoderm
Name the three layers that form during gastrulation
ectoderm - skin, nails, hair & neural tissue
mesoderm - muscle, bone, cartilage, vasculature
endoderm - gut and respiratory system
What is the first well defined neural structure and when does it form?
Neural tube between 20-27 days
Explain the formation of the neural tube
- Neuronal progenitor cells form a neuronal plate
- Plate develops a groove
- Plate folds on itself to form a tube
What is derived from the neural tube?
Brain (rostral tube) and spinal cord (caudal tube)
What happens to the inside of the tube?
It is lined with neuronal progenitors to form the ventricular zone
What does the the hollow centre become?
Ventricular system and the central channel is the spinal cord
Name the three brain vesicles at the start of development
- prosencephalon
- mesencephalon
- rhombencephalon
What does the prosencephalon divide into?
Telencephalon and Diencephalon
What does the telencephalon become?
Cerebrum
What does the diencephalon become?
Eye cup
Thalamus/hypothalamus/epithalamus
What does the mesencephalon become?
Midbrain
Where do the pons and cerebellum originate from?
Mesencephalon
What does the myelencephalon become?
Medulla Oblongata
How is the neocortex formation regulated?
Variable concentrations of signalling molecules decide where the cells will go and what they will do
Name two genes that encode for chemical which are distributed in the brain?
Emx2 and Pax6
Describe the concentrations of Emx2 and Pax6 at the front and back of the brain
Front - low emx2 and high pax6
Back - low pax6 and high emx2
What neurons are formed when there is a low emx2 and high pax6?
Motor neurons
What neutrons form when there is a low pax6 and high emx2?
Visual cortex neurons
When is the foetal period?
Week 9 to term
What happens to the neural tube during the foetal period?
Out pouching of the neural tube and brain. Brain is originally lissencephalic (smooth) but gradually it develops folds
Name the structures that form in the foetal period
Sulci - grooves
gyri - ridges
Why are sulci and gyri required?
To accommodate the proliferating neuronal populations
How do neurons migrate?
- Somal translocation
- Radial glial glial guide
- Tangential migration
What is the function of axons?
Transmit signals from the neuron, develops a synapse when it reaches another neuron
What is the function of dendrites?
Gather information and transmit to neutrons often arranged in a ‘tree like’ formation around the neuron to put in lots of information
What is the key CNS process that occurs after birth?
Myelination
How does myelination occur?
Oligodendrocyte progenitor cells develop processes which wrap around axons to form myelin sheaths to insulate the neuron and increase conduction
What is a key factor in CNS development postnatally?
Experience - stimulation and input
What changes occur in adolescence?
Synapses are eliminated, there is an increase in white matter volume and a change in neurotransmitter systems
After puberty how do the specific hormones cause different responses in boys and girls?
Girls - oestrogen makes them more prone to stress
Boys - androgens makes then more resilient
Name the condition where the neural tube does not close at the top end
Anencephaly (babies don’t survive)
Name the condition where the caudal tube does not close
Spina bifida
Name the condition where the vesicles fail to form, what are the three types?
Holoprosencephaly
- lobar, semilobar, alobar
What are the three types of myelination disorders?
Hypomyelination - does not myelinate fully
Dysmyelination - myelinated incorrectly
Demyelination - myelinates and then loses myelin
Name an example of a myelination disorder
Pelizaeus Merzbacher Disease
Describe Pelizaeus Merzbacher Disease
PLP1 gene codes for a protein which is in myelin responsible for main functions of the sheath
How does Pelizaeus Merzbacher Disease present?
nystagmus, hypotonia, cognitive impairment progresses to spasticity and ataxia